JP7523075B2 - Compound and its manufacturing method, resin, composition, resist film, pattern forming method, underlayer film for lithography, optical component, and method for purifying compound or resin - Google Patents

Description

The present invention relates to a compound and its manufacturing method, a resin, a composition, a resist film, a pattern formation method, an underlayer film for lithography, an optical component, and a method for purifying a compound or resin.

Until now, the most common resist materials have been polymeric resist materials capable of forming amorphous thin films. Examples include polymeric resist materials such as polymethyl methacrylate, and polyhydroxystyrene or polyalkyl methacrylates that have dissociative reactive groups. A solution of such a polymeric resist material is applied to a substrate to produce a resist thin film, which is then irradiated with ultraviolet light, far ultraviolet light, electron beams, extreme ultraviolet light (EUV), X-rays, or the like to form line patterns of about 45 to 100 nm.

However, polymer-based resist materials have a large molecular weight of about 10,000 to 100,000, and a wide molecular weight distribution. For this reason, in lithography using polymer-based resist materials, roughness occurs on the surface of fine patterns, making it difficult to control the pattern dimensions and reducing yields. Therefore, there are limits to how much finer patterns can be produced with lithography using conventional polymer-based resist materials. In order to produce finer patterns, various low-molecular-weight resist materials have been proposed.

For example, alkaline development type negative radiation-sensitive compositions using a low molecular weight polynuclear polyphenol compound as the main component have been proposed (see, for example, Patent Documents 1 and 2). In addition, as a candidate for a low molecular weight resist material having high heat resistance, an alkaline development type negative radiation-sensitive composition using a low molecular weight cyclic polyphenol compound as the main component has also been proposed (see, for example, Patent Document 3 and Non-Patent Document 1). Furthermore, it is known that polyphenol compounds, although they have a low molecular weight, can impart high heat resistance as a base compound of a resist material, and are useful for improving the resolution and roughness of a resist pattern (see, for example, Non-Patent Document 2).

In addition, the reaction mechanism of lithography using electron beams or extreme ultraviolet rays (hereinafter referred to as "EUV") is different from that of normal photolithography. Furthermore, in lithography using electron beams or EUV, the goal is to form fine patterns of several tens of nm. As the resist pattern dimensions become smaller, a resist material with high sensitivity to the exposure light source is required. In particular, in lithography using EUV, it is necessary to increase the sensitivity of the resist composition in terms of throughput.
As resist materials that can solve these problems, inorganic resist materials containing titanium, hafnium, or zirconium have been proposed (see, for example, Patent Documents 4 and 5).

JP 2005-326838 A JP 2008-145539 A JP 2009-173623 A JP 2015-75500 A JP 2015-108781 A

T. Nakayama, M. Nomura, K. Haga, M. Ueda: Bull. Chem. Soc. Jpn. , 71, 2979 (1998) Shinji Okazaki and 22 others, "New Developments in Photoresist Material Development," CMC Publishing Co., Ltd., September 2009, pp. 211-259

However, the compositions described in Patent Document 1 and Patent Document 2 do not have sufficient heat resistance, and the shape of the resulting resist pattern may be poor. The compositions described in Patent Document 3 and Non-Patent Document 1 do not have sufficient solubility in safe solvents used in semiconductor manufacturing processes. In addition, the compositions described in Patent Document 3 and Non-Patent Document 1 do not have sufficient sensitivity, and the shape of the resulting resist pattern may be poor, so further improvement of low molecular weight resist materials is desired. Non-Patent Document 2 does not describe solubility, and the heat resistance of the described compounds is still insufficient, so further improvement of heat resistance is required. In addition, the resist materials described in Patent Documents 4 and 5 have relatively high sensitivity, but still do not have sufficient sensitivity. Furthermore, the resist materials have disadvantages such as low solubility in safe solvents, poor storage stability, and many defects in the film.

The object of the present invention is to provide a compound that has high sensitivity, a high refractive index and transparency in a specific wavelength range, and high solubility in safe solvents, a method for producing the compound, and a resin.

As a result of intensive research into solving the above problems, the inventors discovered that a compound having a specific structure can solve the above problems, and thus completed the present invention.

In other words, the present invention is as follows.

[1] A compound represented by the following formula (X):

(In formula (X), X ₀ is a group represented by the following formula (A-1) or a halogen atom; Y is a single bond, a heteroatom or a divalent group; each P ⁰ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group or a halogen atom; each q is independently an integer of 0 to 3; and each v is independently an integer of 0 to (4+2×q). Two X ₀ may be bonded together to form a group represented by the following formula (A-1-1).)

(In formula (A-1), each R ⁰ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; each p is independently an integer from 0 to 3; and each n is independently an integer from 0 to (5+2×p). * represents connection to Te.)

(In formula (A-1-1), R ⁰ , p, and n are the same as those in formula (A-1), and Z is an oxygen atom, a sulfur atom, or a single bond. * indicates connection to Te.)

[2] The compound according to [1], wherein in the formula (A-1) and the formula (A-1-1), R ⁰ are each independently a hydrocarbon group; a halogen atom; a cyano group; a nitro group; an amino group; an alkyl group having 1 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond; an alkenyl group having 2 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond; an aryl group having 6 to 40 carbon atoms and containing an ether bond, a ketone bond or an ester bond; or a hydroxyl group or a group in which the hydrogen atom of a hydroxyl group is substituted with a crosslinkable reactive group or a dissociable reactive group.

[3] The compound according to [1], wherein the group represented by formula (A-1) is a group represented by the following formula (1A), and the group represented by formula (A-1-1) is a group represented by the following formula (1A-1).

(In formula (1A), p is defined as in formula (A-1), each R ¹ is independently a hydrocarbon group; a halogen atom; a cyano group; a nitro group; an amino group; an alkyl group having 1 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond; an alkenyl group having 2 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond; or an aryl group having 6 to 40 carbon atoms and containing an ether bond, a ketone bond or an ester bond; each R ² is independently a hydrogen atom, a crosslinkable reactive group or a dissociable reactive group; each n ¹ is independently an integer of 0 to (5+2×p), and each n ² is independently an integer of 0 to (5+2×p), with the proviso that at least one n ² is an integer of 1 to (5+2×p). * indicates that the group is connected to Te.)

(In formula (1A-1), p, R ¹ , n ¹ , R ² and n ² are the same as those in formula (1A), and Z is an oxygen atom, a sulfur atom or a single bond. * indicates connection to Te.)

[4] The compound according to [3], wherein in the formula (1A) and the formula (1A-1), R ¹ is each independently the hydrocarbon group which is an alkyl group, an aryl group, or an alkenyl group, or the halogen atom.

[5] A compound according to [3] or [4], in which in formula (1A) and formula (1A-1), p is 0.

[6] The compound according to any one of [3] to [5], wherein in the formula (1A) and the formula (1A-1), n ¹ and n ² are 1.

[7] The compound according to any one of [3] to [6], wherein in each of the formula (1A) and the formula (1A-1), at least one R ² is a dissociable reactive group.

[8] The compound according to any one of [3] to [6], wherein in the formula (1A) and the formula (1A-1), all of the R ² 's are hydrogen atoms.

[9] A resin containing a structural unit derived from a compound described in any one of [1] to [8].

[10] A resin described in [9] containing a structural unit represented by the following formula (B1-M):

In formula (B1-M), each R ³ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; s is an integer of 0 to 3; n ³ is 0 to (4+2×s); Y, P ⁰ , q, and v are the same as those defined in formula (X); R ⁴ is a single bond or a group represented by the following formula (5).

(In formula (5), R ⁵ is a substituted or unsubstituted linear alkylene group having 1 to 20 carbon atoms, a branched alkylene group having 3 to 20 carbon atoms, or a cyclic alkylene group having 3 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and each R ^5' is independently any group of the following formula (5').)

(In formula (5'), * indicates connection to ^R5 .)

[11] The resin according to [10], wherein R ⁴ is a group represented by formula (5).

[12] A resin described in [9] containing a structural unit represented by the following formula (B2-M'):

(In formula (B2-M'), each R ³ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; s is an integer of 0 to 3, and n ³ is 0 to (4+2×s); Y, P ⁰ , q, and v are the same as defined in formula (X); R ⁶ is a substituted or unsubstituted linear, branched, or cyclic trivalent aliphatic group having 1 to 20 carbon atoms, or a substituted or unsubstituted trivalent aromatic group having 6 to 20 carbon atoms; and each R ^6' is independently a group represented by the following formula (6').)

(In formula (6'), * indicates connection to ^R6 .)

[13] A resin according to [9] containing a structural unit represented by the following formula (C1).

(In formula (C1), each R ⁷ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; r is an integer of 0 to 3; and n ⁷ is an integer of 2 to (4+2×r). Y, P ⁰ , q, and v are each defined as in formula (X).)

[14] A method for producing the compound according to any one of [1] to [8], wherein X ₀ in the formula (X) is a halogen atom,
A method for producing a compound, comprising a step of reacting a tellurium halide with a compound represented by the following formula (Y-1):

(In formula (Y-1), Y, P ⁰ , q, and v are the same as those in formula (X).)

[15] A method for producing a compound according to any one of [1] to [8], wherein, in formula (X), X ₀ is a group represented by formula (A-1) or formula (A-1-1),
A method for producing a compound, comprising a step of reacting the compound of formula (X) in which _X0 is a halogen atom with a compound represented by the following formula (B-1) or (B-1-1):

(In formula (B-1), R ⁰ , n and p are the same as those in formula (A-1).)

(In formula (B-1-1), Z, R ⁰ , n and p are the same as those in formula (A-1-1).)

[16] A composition containing a compound according to any one of [1] to [8] or a resin according to any one of [9] to [13].

[17] The composition described in [16], further containing a solvent.

[18] The composition described in [16] or [17], further containing an acid generator.

[19] The composition described in any one of [16] to [18], further comprising an acid crosslinking agent.

[20] The composition described in any one of [16] to [19], further containing a diazonaphthoquinone photoactive compound.

[21] A resist film formed from a composition described in any one of [16] to [20].

[22] A film formation step of forming a film on a substrate using the composition according to any one of [16] to [20];
an exposure step of exposing the film to light;
a developing step for developing the film exposed in the exposure step to form a pattern;
A pattern forming method comprising the steps of:

[23] A composition described in any one of [16] to [20], further containing a silicon-containing compound.

[24] The composition described in [23], wherein the silicon-containing compound is a hydrolyzable organosilane, its hydrolysate, or its hydrolyzed condensate.

[25] An underlayer film for lithography formed using a composition described in any one of [16] to [20], [23] and [24].

[26] An optical component formed using a composition described in any one of [16] to [20].

[27] A step of dissolving the compound according to any one of [1] to [8] or the resin according to any one of [9] to [13] in a solvent containing an organic solvent that is arbitrarily immiscible with water to obtain a solution (A);
a first extraction step of contacting the obtained solution (A) with an acidic aqueous solution to extract impurities in the compound or the resin;
A method for purifying a compound comprising:

[28] The method for purifying a compound or resin described in [27], wherein the acidic aqueous solution is an aqueous solution of one or more mineral acids selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid; or an aqueous solution of one or more organic acids selected from the group consisting of acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, tartaric acid, citric acid, methanesulfonic acid, phenolsulfonic acid, p-toluenesulfonic acid, and trifluoroacetic acid.

[29] A method for purifying a compound or resin described in [27] or [28], wherein the organic solvent that is arbitrarily immiscible with water is one or more organic solvents selected from the group consisting of toluene, 2-heptanone, cyclohexanone, cyclopentanone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, and ethyl acetate.

[30] A method for purifying a compound or resin according to any one of [27] to [29], comprising a second extraction step of contacting the solution phase containing the compound or resin with water after the first extraction step to extract impurities in the compound or resin.

The present invention provides a compound that is highly sensitive, has a high refractive index and transparency in a specific wavelength range, and is highly soluble in safe solvents, as well as a method for producing the compound and a resin.

Hereinafter, an embodiment of the present invention will be described (hereinafter, may be referred to as the "present embodiment"). Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to only the present embodiment.

[Compound]
The compound according to this embodiment is represented by the following formula (X).

(In formula (X), X ₀ is a group represented by the following formula (A-1) or a halogen atom; Y is a single bond, a heteroatom or a divalent group; each P ⁰ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group or a halogen atom; each q is independently an integer of 0 to 3; and each v is independently an integer of 0 to (4+2×q). Two X ₀ may be bonded together to form a group represented by the following formula (A-1-1).)

(In formula (A-1), each R ⁰ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; each p is independently an integer from 0 to 3; and each n is independently an integer from 0 to (5+2×p). * represents connection to Te.)

(In formula (A-1-1), R ⁰ , p, and n are the same as those in formula (A-1), and Z is an oxygen atom, a sulfur atom, or a single bond. * indicates connection to Te.)

The chemical structure of the compound according to this embodiment can be determined by ¹ H-NMR analysis. The compound according to this embodiment has high sensitivity, a high refractive index and transparency in a specific wavelength region, and high solubility in safe solvents. In addition, since the compound according to this embodiment contains tellurium as shown in the formula (X), a sensitizing effect can be expected, particularly in EUV lithography. In addition, since the compound has a benzene skeleton or a naphthalene skeleton, it has excellent heat resistance.

In the formula (X), X ₀ is a group represented by the formula (A-1) or a halogen atom. Two X ₀ may be bonded together to form a group represented by the formula (A-1-1). The group represented by the formula (A-1-1) is a divalent group in which two groups represented by the formula (A-1) are bonded by Z, and each of the two *'s is connected to Te. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In the formula (A-1), p is an integer of 0 to 3, each independently, and is a value that determines the structure of a (condensed) ring structure (hereinafter, the ring structure may be referred to as "ring structure A"). That is, as shown below, in the formula (A-1), when p = 0, the ring structure A is a benzene structure, when p = 1, the ring structure A is a naphthalene structure, when p = 2, the ring structure A is a three-ring structure such as anthracene or phenanthrene, and when p = 3, the ring structure A is a four-ring structure such as pyrene. Although not particularly limited, the ring structure A is preferably a benzene structure or a naphthalene structure (p = 0 or 1) from the viewpoint of solubility. In the formula (A-1), R ⁰ and Te (*) are bonded to any bondable site on the ring structure A.

In the formula (A-1), R ⁰ is a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom.

Here, examples of monovalent groups containing an oxygen atom include, but are not limited to, acyl groups having 1 to 20 carbon atoms, alkoxycarbonyl groups having 2 to 20 carbon atoms, linear alkyloxy groups having 1 to 6 carbon atoms, branched alkyloxy groups having 3 to 20 carbon atoms, cyclic alkyloxy groups having 3 to 20 carbon atoms, linear alkenyloxy groups having 2 to 6 carbon atoms, branched alkenyloxy groups having 3 to 6 carbon atoms, cyclic alkenyloxy groups having 3 to 10 carbon atoms, aryloxy groups having 6 to 10 carbon atoms, and aryloxy groups having 6 to 10 carbon atoms. Examples of such groups include an oxy group, an acyloxy group having 1 to 20 carbon atoms, an alkoxycarbonyloxy group having 2 to 20 carbon atoms, an alkoxycarbonylalkyl group having 3 to 20 carbon atoms, a 1-substituted alkoxymethyl group having 2 to 20 carbon atoms, a cyclic etheroxy group having 2 to 20 carbon atoms, an alkoxyalkyloxy group having 2 to 20 carbon atoms, a glycidyloxy group, an allyloxy group, a (meth)acrylic group, a glycidyl acrylate group, a glycidyl methacrylate group, and a hydroxyl group.

Examples of acyl groups having 1 to 20 carbon atoms include, but are not limited to, methanoyl (formyl), ethanoyl (acetyl), propanoyl, butanoyl, pentanoyl, hexanoyl, octanoyl, decanoyl, and benzoyl groups.

Examples of alkoxycarbonyl groups having 2 to 20 carbon atoms include, but are not limited to, methoxycarbonyl groups, ethoxycarbonyl groups, propoxycarbonyl groups, butoxycarbonyl groups, pentyloxycarbonyl groups, hexyloxycarbonyl groups, octyloxycarbonyl groups, and decyloxycarbonyl groups.

Examples of linear alkyloxy groups having 1 to 6 carbon atoms include, but are not limited to, methoxy groups, ethoxy groups, n-propoxy groups, n-butoxy groups, n-pentyloxy groups, and n-hexyloxy groups.

Examples of branched alkyloxy groups having 3 to 20 carbon atoms include, but are not limited to, isopropoxy groups, isobutoxy groups, and tert-butoxy groups.

Examples of cyclic alkyloxy groups having 3 to 20 carbon atoms include, but are not limited to, cyclopropoxy groups, cyclobutoxy groups, cyclopentyloxy groups, cyclohexyloxy groups, cyclooctyloxy groups, and cyclodecyloxy groups.

Examples of linear alkenyloxy groups having 2 to 6 carbon atoms include, but are not limited to, vinyloxy groups, 1-propenyloxy groups, 2-propenyloxy groups, 1-butenyloxy groups, and 2-butenyloxy groups.

Examples of branched alkenyloxy groups having 3 to 6 carbon atoms include, but are not limited to, isopropenyloxy groups, isobutenyloxy groups, isopentenyloxy groups, and isohexenyloxy groups.

Examples of cyclic alkenyloxy groups having 3 to 10 carbon atoms include, but are not limited to, cyclopropenyloxy groups, cyclobutenyloxy groups, cyclopentenyloxy groups, cyclohexenyloxy groups, cyclooctenyloxy groups, and cyclodecenyloxy groups.

Examples of aryloxy groups having 6 to 10 carbon atoms include, but are not limited to, phenyloxy groups (phenoxy groups), 1-naphthyloxy groups, and 2-naphthyloxy groups.

Examples of acyloxy groups having 1 to 20 carbon atoms include, but are not limited to, formyloxy groups, acetyloxy groups, propionyloxy groups, butyryloxy groups, isobutyryloxy groups, and benzoyloxy groups.

Examples of alkoxycarbonyloxy groups having 2 to 20 carbon atoms include, but are not limited to, methoxycarbonyloxy groups, ethoxycarbonyloxy groups, propoxycarbonyloxy groups, butoxycarbonyloxy groups, octyloxycarbonyloxy groups, and decyloxycarbonyloxy groups.

Examples of alkoxycarbonylalkyl groups having 3 to 20 carbon atoms include, but are not limited to, a methoxycarbonylmethyl group, an ethoxycarbonylmethyl group, an n-propoxycarbonylmethyl group, an isopropoxycarbonylmethyl group, and an n-butoxycarbonylmethyl group.

Examples of 1-substituted alkoxymethyl groups having 2 to 20 carbon atoms include, but are not limited to, 1-cyclopentylmethoxymethyl, 1-cyclopentylethoxymethyl, 1-cyclohexylmethoxymethyl, 1-cyclohexylethoxymethyl, 1-cyclooctylmethoxymethyl, and 1-adamantylmethoxymethyl.

Examples of cyclic etheroxy groups having 2 to 20 carbon atoms include, but are not limited to, tetrahydropyranyloxy groups, tetrahydrofuranyloxy groups, tetrahydrothiopyranyloxy groups, tetrahydrothiofuranyloxy groups, 4-methoxytetrahydropyranyloxy groups, and 4-methoxytetrahydrothiopyranyloxy groups.

Examples of alkoxyalkyloxy groups having 2 to 20 carbon atoms include, but are not limited to, methoxymethoxy groups, ethoxyethoxy groups, cyclohexyloxymethoxy groups, cyclohexyloxyethoxy groups, phenoxymethoxy groups, and phenoxyethoxy groups.

(Meth)acrylic groups include, but are not limited to, acryloyloxy groups, methacryloyloxy groups, etc. Furthermore, the glycidyl acrylate group is not particularly limited as long as it can be obtained by reacting acrylic acid with a glycidyloxy group. Furthermore, the glycidyl methacrylate group is not particularly limited as long as it can be obtained by reacting methacrylic acid with a glycidyloxy group.

Examples of the monovalent group containing a sulfur atom include, but are not limited to, a thiol group. The monovalent group containing a sulfur atom is preferably a group in which a sulfur atom is directly bonded to a carbon atom constituting the ring structure A in formula (A-1).

Examples of the monovalent group containing a nitrogen atom include, but are not limited to, a nitro group, an amino group, a diazo group, etc. The monovalent group containing a nitrogen atom is preferably a group in which a nitrogen atom is directly bonded to a carbon atom constituting the ring structure A in formula (A-1).

Examples of hydrocarbon groups include, but are not limited to, linear alkyl groups having 1 to 20 carbon atoms, branched alkyl groups having 3 to 6 carbon atoms, cyclic alkyl groups having 3 to 20 carbon atoms, linear alkenyl groups having 2 to 20 carbon atoms, branched alkenyl groups having 3 to 20 carbon atoms, cyclic alkenyl groups having 3 to 20 carbon atoms, and aryl groups having 6 to 20 carbon atoms.

Examples of linear alkyl groups having 1 to 20 carbon atoms include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-decyl, and n-dodecyl groups.

Examples of branched alkyl groups having 3 to 20 carbon atoms include, but are not limited to, isopropyl, isobutyl, tert-butyl, neopentyl, 2-hexyl, 2-decyl, and 2-dodecyl groups.

Examples of cyclic alkyl groups having 3 to 20 carbon atoms include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclodecyl, adamantyl, bicyclohexyl, and tricyclodecyl groups.

Examples of linear alkenyl groups having 2 to 20 carbon atoms include, but are not limited to, vinyl groups, 1-propenyl groups, 2-propenyl groups (allyl groups), 1-butenyl groups, 2-butenyl groups, 2-pentenyl groups, 2-hexenyl groups, 2-decylinyl groups, and 2-dodecylinyl groups.

Examples of branched alkenyl groups having 3 to 20 carbon atoms include, but are not limited to, isopropenyl, isobutenyl, isopentenyl, isohexenyl, isodecyl, and isododecyl groups.

Examples of cyclic alkenyl groups having 3 to 20 carbon atoms include, but are not limited to, cyclopropenyl groups, cyclobutenyl groups, cyclopentenyl groups, cyclohexenyl groups, cycloheptanyl groups, cyclooctenyl groups, cyclodecenyl groups, and cyclododecenyl groups.

Examples of aryl groups having 6 to 20 carbon atoms include, but are not limited to, phenyl groups, naphthyl groups, biphenyl groups, fluorenyl groups, anthracenyl groups, and pyrenyl groups.

Examples of halogen atoms include, but are not limited to, fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

In the formula (A-1), each n is independently an integer from 0 to (5+2×p). In this embodiment, from the viewpoint of solubility in a solvent, it is preferable that at least one of the n's in the formula (A-1) is an integer from 1 to 4.

In the present embodiment, from the viewpoint of solubility in a solvent and introduction of crosslinkability, it is preferable that at least one of R ⁰ in the formula (A-1) is a monovalent group containing an oxygen atom.

In the formula (A-1-1), Z is an oxygen atom, a sulfur atom, or a single bond. Although there is no particular limitation, Z is preferably an oxygen atom or a sulfur atom from the viewpoint of heat resistance. In the formula (A-1-1), Z is bonded to any bondable site on the ring structure.

In the formula (A-1) and the formula (A-1-1), from the viewpoint of curability, it is preferable that R ⁰ is each independently a hydrocarbon group; a halogen atom; a cyano group; a nitro group; an amino group; an alkyl group having 1 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond; an alkenyl group having 2 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond; an aryl group having 6 to 40 carbon atoms and containing an ether bond, a ketone bond or an ester bond; or a hydroxyl group or a group in which the hydrogen atom of a hydroxyl group is substituted with a crosslinkable reactive group or a dissociable reactive group.

Examples of the hydrocarbon group include linear, branched, and cyclic hydrocarbon groups. Examples of the hydrocarbon group include alkyl groups, alkenyl groups, and aryl groups, such as alkyl groups having 1 to 30 carbon atoms, alkenyl groups having 2 to 30 carbon atoms, and aryl groups having 6 to 40 carbon atoms.

Examples of linear, branched or cyclic hydrocarbon groups include, but are not limited to, linear alkyl groups having 1 to 30 carbon atoms, branched alkyl groups having 3 to 30 carbon atoms, and cyclic alkyl groups having 3 to 30 carbon atoms.

Examples of linear alkyl groups having 1 to 30 carbon atoms include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl groups.

Examples of branched alkyl groups having 3 to 30 carbon atoms include, but are not limited to, isopropyl, isobutyl, tert-butyl, neopentyl, and 2-hexyl groups.

Examples of cyclic alkyl groups having 3 to 30 carbon atoms include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, and cyclodecyl groups.

Examples of aryl groups include, but are not limited to, aryl groups having 6 to 40 carbon atoms, such as phenyl groups and naphthyl groups.

Examples of alkenyl groups include, but are not limited to, linear alkenyl groups having 2 to 30 carbon atoms, branched alkenyl groups having 3 to 30 carbon atoms, and cyclic alkenyl groups having 3 to 30 carbon atoms.

Examples of linear alkenyl groups having 2 to 30 carbon atoms include, but are not limited to, vinyl groups, 1-propenyl groups, 2-propenyl groups (allyl groups), 1-butenyl groups, 2-butenyl groups, 2-pentenyl groups, and 2-hexenyl groups.

Examples of branched alkenyl groups having 3 to 30 carbon atoms include, but are not limited to, isopropenyl groups, isobutenyl groups, isopentenyl groups, isohexenyl groups, etc.

Examples of cyclic alkenyl groups having 3 to 30 carbon atoms include, but are not limited to, cyclopropenyl groups, cyclobutenyl groups, cyclopentenyl groups, cyclohexenyl groups, cycloheptanyl groups, cyclooctenyl groups, and cyclodecenyl groups.

Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

Examples of alkyl groups having 1 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond include methyloxymethyl, ethyloxymethyl, n-propyloxymethyl, n-butyloxymethyl, n-pentyloxymethyl, n-hexyloxymethyl, isopropyloxymethyl, isobutyloxymethyl, tert-butyloxymethyl, neopentyloxymethyl, 2-hexyloxymethyl, cyclopropyloxymethyl, cyclobutyloxymethyl, cyclopentyloxymethyl, cyclohexyloxymethyl, cyclooctyloxymethyl, cyclodecyloxymethyl, methylcarbonylmethyl, ethylcarbonylmethyl, n-propylcarbonylmethyl, n-butylcarbonylmethyl, n-pentylcarbonylmethyl, n-hexylcarbonylmethyl, isopropylcarbonylmethyl, isobutylcarbonylmethyl, tert-butylcarbonylmethyl, neopentylcarbonylmethyl, 2-hexyloxymethyl, carbonylmethyl group, cyclopropylcarbonylmethyl group, cyclobutylcarbonylmethyl group, cyclopentylcarbonylmethyl group, cyclohexylcarbonylmethyl group, cyclooctylcarbonylmethyl group, cyclodecylcarbonylmethyl group, methyloxycarbonylmethyl group, ethyloxycarbonylmethyl group, n-propyloxycarbonylmethyl group, n-butyloxycarbonylmethyl group, n-pentyloxycarbonylmethyl group, n-hexyloxycarbonylmethyl group, isopropyloxycarbonylmethyl group, isobutyloxycarbonylmethyl group, tert-butyloxycarbonylmethyl group, neopentyloxycarbonylmethyl group, 2-hexyloxycarbonylmethyl group, cyclopropyloxycarbonylmethyl group, cyclobutyloxycarbonylmethyl group, cyclopentyloxycarbonylmethyl group, cyclohexyloxycarbonylmethyl group, cyclooctyloxycarbonylmethyl group, cyclodecyloxycarbonylmethyl group, and the like.

Examples of alkenyl groups having 2 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond include a vinyloxymethyl group, a 1-propenyloxymethyl group, a 2-propenyloxymethyl group (allyloxymethyl group), a 1-butenyloxymethyl group, a 2-butenyloxymethyl group, a 2-pentenyloxymethyl group, a 2-hexenyloxymethyl group, an isopropenyloxymethyl group, an isobutenyloxymethyl group, an isopentenyloxymethyl group, an isohexenyloxymethyl group, a cyclopropenyloxymethyl group, a cyclobutenyloxymethyl group, and a cyclopentenyloxymethyl group. alkyl group, cyclohexenyloxymethyl group, cycloheptanyloxymethyl group, cyclooctenyloxymethyl group, cyclodecenyloxymethyl group, vinylcarbonylmethyl group, 1-propenylcarbonylmethyl group, 2-propenylcarbonylmethyl group (allylcarbonylmethyl group), 1-butenylcarbonylmethyl group, 2-butenylcarbonylmethyl group, 2-pentenylcarbonylmethyl group, 2-hexenylcarbonylmethyl group, isopropenylcarbonylmethyl group, isobutenylcarbonylmethyl group, isopentenylcarbonylmethyl group, isohexenylcarbonyl Methyl group, cyclopropenylcarbonylmethyl group, cyclobutenylcarbonylmethyl group, cyclopentenylcarbonylmethyl group, cyclohexenylcarbonylmethyl group, cycloheptanylcarbonylmethyl group, cyclooctenylcarbonylmethyl group, cyclodecenylcarbonylmethyl group, vinyloxycarbonylmethyl group, 1-propenyloxycarbonylmethyl group, 2-propenyloxycarbonylmethyl group (allyloxycarbonylmethyl group), 1-butenyloxycarbonylmethyl group, 2-butenyloxycarbonylmethyl group, 2-pentenyloxycarbonyl Examples of the alkyl group include a methyl group, a 2-hexenyloxycarbonylmethyl group, an isopropenyloxycarbonylmethyl group, an isobutenyloxycarbonylmethyl group, an isopentenyloxycarbonylmethyl group, an isohexenyloxycarbonylmethyl group, a cyclopropenyloxycarbonylmethyl group, a cyclobutenyloxycarbonylmethyl group, a cyclopentenyloxycarbonylmethyl group, a cyclohexenyloxycarbonylmethyl group, a cycloheptanyloxycarbonylmethyl group, a cyclooctenyloxycarbonylmethyl group, and a cyclodecenyloxycarbonylmethyl group.

Examples of aryl groups having 6 to 40 carbon atoms and containing an ether bond, a ketone bond or an ester bond include phenyloxymethyl, naphthyloxymethyl, phenylcarbonylmethyl, naphthylcarbonylmethyl, phenyloxycarbonylmethyl, naphthyloxycarbonylmethyl, etc. Crosslinkable reactive groups and dissociable reactive groups will be described later.

It is preferable that the group represented by the formula (A-1) is a group represented by the following formula (1A), and the group represented by the formula (A-1-1) is a group represented by the following formula (1A-1).

(In formula (1A), p is defined as in formula (A-1), each R ¹ is independently a hydrocarbon group; a halogen atom; a cyano group; a nitro group; an amino group; an alkyl group having 1 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond; an alkenyl group having 2 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond; or an aryl group having 6 to 40 carbon atoms and containing an ether bond, a ketone bond or an ester bond; each R ² is independently a hydrogen atom, a crosslinkable reactive group or a dissociable reactive group; each n ¹ is independently an integer of 0 to (5+2×p), and each n ² is independently an integer of 0 to (5+2×p), with the proviso that at least one n ² is an integer of 1 to (5+2×p). * indicates that the group is connected to Te.)

(In formula (1A-1), p, R ¹ , n ¹ , R ² and n ² are the same as those in formula (1A), and Z is an oxygen atom, a sulfur atom or a single bond. * indicates connection to Te.)

In formula (1A), n ¹ is independently an integer of 0 to (5+2×p), and n ² is independently an integer of 0 to (5+2×p). At least one n ² is an integer of 1 to (5+2×p). That is, the group represented by formula (1A) has at least one "-OR ² " with respect to the ring structure A. In formula (1A) and formula (1A-1), Z, R ¹ , -OR ² , and Te(*) are bonded to any bondable site on the ring structure A. Therefore, the upper limit of n ¹ +n ² in one ring structure A is the same as the upper limit of the number of bondable sites of the ring structure A after taking into account Te(*) (and Z) and the bonded sites. Note that n ¹ +n ² is the same as n in formula (A-1).

Each R ¹ is independently a hydrocarbon group, a halogen atom, a cyano group, a nitro group, an amino group, an alkyl group having 1 to 30 carbon atoms and including an ether bond, a ketone bond or an ester bond, an alkenyl group having 2 to 30 carbon atoms and including an ether bond, a ketone bond or an ester bond, or an aryl group having 6 to 40 carbon atoms and including an ether bond, a ketone bond or an ester bond. R ¹ can be the same as R ⁰ in the above-mentioned formula (A-1) and formula (A-1-1).

In formula (1A), each R ² is independently a hydrogen atom, a crosslinkable reactive group, or a dissociable reactive group.

In this embodiment, the term "crosslinkable reactive group" refers to a group that reacts in the presence of a radical or an acid/alkali and changes the solubility in the acid, alkali, or organic solvent used in the coating solvent or developer. Examples of crosslinkable reactive groups include allyl groups, (meth)acryloyl groups, vinyl groups, epoxy groups, alkoxymethyl groups, and cyano groups, but are not limited to these as long as they react in the presence of a radical or an acid/alkali. From the viewpoint of improving productivity, it is preferable that the crosslinkable reactive group has the property of undergoing a chain cleavage reaction in the presence of an acid.

In this embodiment, the term "dissociable reactive group" refers to a group that can be cleaved to generate an alkali-soluble group. Examples of the alkali-soluble group include, but are not limited to, a phenolic hydroxyl group, a carboxyl group, a sulfonic acid group, and a hexafluoroisopropanol group. Phenolic hydroxyl groups and carboxyl groups are preferred, and phenolic hydroxyl groups are particularly preferred. The dissociable reactive group is not limited to, but can be appropriately selected from those proposed in, for example, hydroxystyrene-based resins and (meth)acrylic acid-based resins used in chemically amplified resist compositions for KrF and ArF.

Preferred examples of the dissociable reactive group include a substituted methyl group, a 1-substituted ethyl group, a 1-substituted n-propyl group, a 1-branched alkyl group, a silyl group, an acyl group, a 1-substituted alkoxymethyl group, a cyclic ether group, an alkoxycarbonyl group, and an alkoxycarbonylalkyl group, which have the property of being dissociated by an acid. It is preferable that the dissociable reactive group does not have a crosslinkable functional group.

The substituted methyl group is not particularly limited, but can usually be a substituted methyl group having 2 to 20 carbon atoms, preferably a substituted methyl group having 4 to 18 carbon atoms, and more preferably a substituted methyl group having 6 to 16 carbon atoms. Specific examples of the substituted methyl group include, but are not limited to, a methoxymethyl group, a methylthiomethyl group, an ethoxymethyl group, an n-propoxymethyl group, an isopropoxymethyl group, an n-butoxymethyl group, a t-butoxymethyl group, a 2-methylpropoxymethyl group, an ethylthiomethyl group, a methoxyethoxymethyl group, a phenyloxymethyl group, a 1-cyclopentyloxymethyl group, a 1-cyclohexyloxymethyl group, a benzylthiomethyl group, a phenacyl group, a 4-bromophenacyl group, a 4-methoxyphenacyl group, a piperonyl group, and the group of substituents represented by the following formula (13-1). Specific examples of R ^2A in the following formula (13-1) include, but are not limited to, a methyl group, an ethyl group, an isopropyl group, an n-propyl group, a t-butyl group, an n-butyl group, and the like.

In the above formula (13-1), R ^2A is an alkyl group having 1 to 4 carbon atoms.

The 1-substituted ethyl group is not particularly limited, but can usually be a 1-substituted ethyl group having 3 to 20 carbon atoms, preferably a 1-substituted ethyl group having 5 to 18 carbon atoms, and more preferably a substituted ethyl group having 7 to 16 carbon atoms. Specific examples of the 1-substituted ethyl group include, but are not limited to, a 1-methoxyethyl group, a 1-methylthioethyl group, a 1,1-dimethoxyethyl group, a 1-ethoxyethyl group, a 1-ethylthioethyl group, a 1,1-diethoxyethyl group, a n-propoxyethyl group, a isopropoxyethyl group, a n-butoxyethyl group, a t-butoxyethyl group, a 2-methylpropoxyethyl group, a 1-phenoxyethyl group, a 1-phenylthioethyl group, a 1,1-diphenoxyethyl group, a 1-cyclopentyloxyethyl group, a 1-cyclohexyloxyethyl group, a 1-phenylethyl group, a 1,1-diphenylethyl group, and the group of substituents represented by the following formula (13-2).

In the formula (13-2), R ^2A has the same meaning as in the formula (13-1).

The 1-substituted n-propyl group is not particularly limited, but can usually be a 1-substituted n-propyl group having 4 to 20 carbon atoms, preferably a 1-substituted n-propyl group having 6 to 18 carbon atoms, and more preferably a 1-substituted n-propyl group having 8 to 16 carbon atoms. Specific examples of the 1-substituted n-propyl group include, but are not limited to, a 1-methoxy-n-propyl group and a 1-ethoxy-n-propyl group.

The 1-branched alkyl group is not particularly limited, but can usually be a 1-branched alkyl group having 3 to 20 carbon atoms, preferably a 1-branched alkyl group having 5 to 18 carbon atoms, and more preferably a branched alkyl group having 7 to 16 carbon atoms. Specific examples of the 1-branched alkyl group include, but are not limited to, an isopropyl group, a sec-butyl group, a tert-butyl group, a 1,1-dimethylpropyl group, a 1-methylbutyl group, a 1,1-dimethylbutyl group, a 2-methyladamantyl group, and a 2-ethyladamantyl group.

The silyl group is not particularly limited, but can usually be a silyl group having 1 to 20 carbon atoms, preferably a silyl group having 3 to 18 carbon atoms, and more preferably a silyl group having 5 to 16 carbon atoms. Specific examples of the silyl group include, but are not limited to, a trimethylsilyl group, an ethyldimethylsilyl group, a methyldiethylsilyl group, a triethylsilyl group, a tert-butyldimethylsilyl group, a tert-butyldiethylsilyl group, a tert-butyldiphenylsilyl group, a tri-tert-butylsilyl group, and a triphenylsilyl group.

The acyl group is not particularly limited, but can usually be an acyl group having 2 to 20 carbon atoms, preferably an acyl group having 4 to 18 carbon atoms, and more preferably an acyl group having 6 to 16 carbon atoms. Specific examples of the acyl group include, but are not limited to, an acetyl group, a phenoxyacetyl group, a propionyl group, a butyryl group, a heptanoyl group, a hexanoyl group, a valeryl group, a pivaloyl group, a isovaleryl group, a lauryl group, an adamantylcarbonyl group, a benzoyl group, and a naphthoyl group.

The 1-substituted alkoxymethyl group is not particularly limited, but can typically be a 1-substituted alkoxymethyl group having 2 to 20 carbon atoms, preferably a 1-substituted alkoxymethyl group having 4 to 18 carbon atoms, and more preferably a 1-substituted alkoxymethyl group having 6 to 16 carbon atoms. Specific examples of the 1-substituted alkoxymethyl group include, but are not limited to, a 1-cyclopentylmethoxymethyl group, a 1-cyclopentylethoxymethyl group, a 1-cyclohexylmethoxymethyl group, a 1-cyclohexylethoxymethyl group, a 1-cyclooctylmethoxymethyl group, and a 1-adamantylmethoxymethyl group.

The cyclic ether group is not particularly limited, but can usually be a cyclic ether group having 2 to 20 carbon atoms, preferably a cyclic ether group having 4 to 18 carbon atoms, and more preferably a cyclic ether group having 6 to 16 carbon atoms. Specific examples of the cyclic ether group include, but are not limited to, a tetrahydropyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group, a tetrahydrothiofuranyl group, a 4-methoxytetrahydropyranyl group, and a 4-methoxytetrahydrothiopyranyl group.

The alkoxycarbonyl group can usually be an alkoxycarbonyl group having 2 to 20 carbon atoms, preferably an alkoxycarbonyl group having 4 to 18 carbon atoms, and more preferably an alkoxycarbonyl group having 6 to 16 carbon atoms. Specific examples of the alkoxycarbonyl group include, but are not limited to, a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl group, a tert-butoxycarbonyl group, or a dissociative reactive group group represented by the following formula (13-3) where n = 0.

The alkoxycarbonylalkyl group is not particularly limited, but can usually be an alkoxycarbonylalkyl group having 3 to 20 carbon atoms, preferably an alkoxycarbonylalkyl group having 4 to 18 carbon atoms, and more preferably an alkoxycarbonylalkyl group having 6 to 16 carbon atoms. Specific examples of the alkoxycarbonylalkyl group include, but are not limited to, a methoxycarbonylmethyl group, an ethoxycarbonylmethyl group, an n-propoxycarbonylmethyl group, an isopropoxycarbonylmethyl group, an n-butoxycarbonylmethyl group, or a dissociative reactive group group represented by the following formula (13-3) where n = 1 to 4.

In the formula (13-3), R ^3A represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms; n represents an integer of 0 to 4.

Among these dissociative reactive groups, substituted methyl groups, 1-substituted ethyl groups, 1-substituted alkoxymethyl groups, cyclic ether groups, alkoxycarbonyl groups, and alkoxycarbonylalkyl groups are preferred, and from the viewpoint of exhibiting higher sensitivity, substituted methyl groups, 1-substituted ethyl groups, alkoxycarbonyl groups, and alkoxycarbonylalkyl groups are more preferred, and furthermore, dissociative reactive groups having a structure selected from cycloalkanes having 3 to 12 carbon atoms, lactones, and aromatic rings having 6 to 12 carbon atoms are even more preferred. The cycloalkanes having 3 to 12 carbon atoms may be monocyclic or polycyclic, but polycyclic rings are preferred. Specific examples of cycloalkanes having 3 to 12 carbon atoms include, but are not limited to, monocycloalkanes, bicycloalkanes, tricycloalkanes, tetracycloalkanes, etc., and more specifically, monocycloalkanes such as cyclopropane, cyclobutane, cyclopentane, and cyclohexane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclodecane, etc., are included. Among these, adamantane, tricyclodecane, and tetracyclodecane are preferred, and adamantane and tricyclodecane are more preferred. The cycloalkane having 3 to 12 carbon atoms may have a substituent. Examples of lactones include, but are not limited to, butyrolactone and cycloalkanes having 3 to 12 carbon atoms and having a lactone group. Examples of aromatic rings having 6 to 12 carbon atoms include, but are not limited to, a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and a pyrene ring, with a benzene ring and a naphthalene ring being preferred, and a naphthalene ring being more preferred. In particular, the dissociative reactive group group represented by the following formula (13-4) is preferred due to its high resolution.

In the formula (13-4), R ^5A is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, R ^6A is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, a cyano group, a nitro group, a heterocyclic group, a halogen atom, or a carboxyl group, n _1A is an integer of 0 to 4, n _2A is an integer of 1 to 5, and n _0A is an integer of 0 to 4.

Due to the structural characteristics described above, the compound having the group represented by the formula (1A) has high heat resistance due to its rigidity even though it has a low molecular weight, and can be used under high-temperature baking conditions. Furthermore, the lithography material according to this embodiment containing the compound has such a low molecular weight and can be baked at high temperatures, and further contains a compound containing tellurium, so it has high sensitivity and can provide a good resist pattern shape.

In the formula (1A) and the formula (1A-1), from the viewpoint of solubility in a safe solvent, it is preferable that each R ¹ is independently a hydrocarbon group such as an alkyl group, an aryl group, or an alkenyl group, or a halogen atom.

In the formula (1A) and the formula (1A-1), it is preferable that p is 0 in terms of solubility in a safe solvent, resist pattern characteristics, and heat resistance. In particular, it is preferable that p is 0 in the formula (1A).

In the formula (1A) and the formula (1A-1), from the viewpoint of ease of production, it is preferable that ⁿ¹ and ⁿ² are 1. In particular, it is preferable that p is 0, and ⁿ¹ and ⁿ² are 1 in the formula (1A).

In the present embodiment, when a positive pattern is formed by alkali development or a negative pattern is formed by organic development, from the viewpoint of obtaining a good pattern shape, in each of the formula (1A) and the formula (1A-1), at least one R ² is preferably a dissociable reactive group.

In the present embodiment, when a negative pattern is formed by alkali development, from the viewpoint of obtaining a good pattern shape, all of the R ^2s in the formulae (1A) and (1A-1) may be hydrogen atoms.

In the formula (X), Y is a single bond, a heteroatom, or a divalent group. Examples of the heteroatom include an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. The heteroatom may not include a nitrogen atom. Examples of the divalent group include a methylene group, an ethylene group, a cyclohexylene group, a carbonyl group, and a carbonyloxy group.

In the formula (X), P ⁰ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom. P ⁰ can be the same as R ⁰ in the formula (A-1). Each q is independently an integer of 0 to 3, and is a value that determines the condensed ring structure in the same way as p in the formula (A-1). As in the formula (A-1), when q = 0, it indicates a benzene structure, when q = 1, it indicates a naphthalene structure, when q = 2, it indicates a three-ring structure such as anthracene or phenanthrene, and when q = 3, it indicates a four-ring structure such as pyrene. From the viewpoint of solubility, q is preferably 0 or 1. In the formula (X), p ⁰ is bonded to any bondable site on the ring structure. Each v is independently an integer of 0 to (4 + 2 × q).

Specific examples of the compound in which X ₀ in the formula (X) is a group represented by the formula (A-1) include the following compounds.

In the formula (X), specific examples of the compound in which two X ₀ are bonded to each other to form a group represented by the formula (A-1-1) include the following compounds.

In the above formula (X), specific examples of the compound in which X ₀ is a halogen atom include the following compounds.

[Method of producing the compound]
In the present embodiment, the method for producing the compound represented by formula (X) is not particularly limited. For example, the method for producing the compound in which _X0 in formula (X) is a halogen atom can include a step of reacting a tellurium halide with a compound represented by the following formula (Y-1).

(In formula (Y-1), Y, P ⁰ , q, and v are the same as those in formula (X).)

The tellurium halide is not particularly limited, and examples thereof include tellurium (IV) tetrafluoride, tellurium (IV) tetrachloride, tellurium (IV) tetrabromide, tellurium (IV) tetraiodide, etc. The compound represented by the formula (Y-1) is commercially available.

The condensation reaction of the tellurium halide with the compound represented by formula (Y-1) can be carried out in the presence of a catalyst. The catalyst is preferably an acidic catalyst or a basic catalyst, more preferably a Lewis acid or a Lewis base. The Lewis acid is not particularly limited, but is preferably a Lewis acid capable of bidentate or higher coordination. Specific examples include boron trifluoride, aluminum chloride, methyldichloroaluminum, dimethylchloroaluminum, trimethylaluminum, magnesium chloride, magnesium bromide, titanium tetrachloride, dichlorotitanium bistriflate, biscyclopentadienyltitanium bistriflate, dichlorotitanium bisfluorosulfonate, tin tetrachloride, tin(II) bistriflate, etc. Titanium tetrachloride can also be used in combination with a catalytic amount of methanesulfonic acid trimethylsilyl ether. The Lewis base is not particularly limited, but specific examples include triethylamine, tributylamine, ethyldiisopropylamine, tetramethylenediamine, N-ethylpiperidine, diazabicyclo[2,2,0]undecene, diazabicyclo[3,3,0]octane, etc. The combination of the Lewis acid and Lewis base used can be appropriately selected depending on the combination of the compounds to be reacted, and among them, the combination of titanium tetrachloride and triethylamine is preferred.

The condensation reaction of the tellurium halide with the compound represented by formula (Y-1) can be carried out in a solvent. There are no particular limitations on the solvent as long as it does not affect the Lewis acid used. Specific examples of the solvent include chlorine-based solvents such as methylene chloride, chloroform, and chlorobenzene, and hydrocarbon-based solvents such as benzene, toluene, hexane, and cyclohexane. These can be used alone or in combination of two or more. In particular, methylene chloride and chlorobenzene are preferred.

The conditions for the condensation reaction between the tellurium halide and the compound represented by formula (Y-1) are not particularly limited and can be appropriately selected depending on the reactivity of the reaction raw materials, but can be, for example, carried out at -70°C to 40°C for 0.5 to 120 hours.

The method for producing the compound in which _X0 in the formula (X) is a group represented by the formula (A-1) or the formula (A-1-1) is not particularly limited, and may include, for example, a step of reacting the compound in which _X0 in the formula (X) is a halogen atom with a compound represented by the following formula (B-1) or the following formula (B-1-1).

(In formula (B-1), R ⁰ , n and p are the same as those in formula (A-1).)

(In formula (B-1-1), Z, R ⁰ , n and p are the same as those in formula (A-1-1).)

The compound of formula (X) in which _X0 is a halogen atom can be produced by the above-mentioned method. The reaction of the compound of formula (X) in which _X0 is a halogen atom with the compound of formula (B-1) or formula (B-1-1) below can be carried out, for example, as follows.

For example, the reaction of a compound in which X ₀ in formula (X) is a halogen atom with a compound represented by formula (B-1) or formula (B-1-1) below can be carried out in the presence of a catalyst. As the catalyst, an acidic catalyst or a basic catalyst is preferred, and a Lewis acid or a Lewis base is more preferred. As the Lewis acid, there is no particular limitation, but among them, a Lewis acid having bidentate or higher coordination ability is preferred. Specific examples include boron trifluoride, aluminum chloride, methyldichloroaluminum, dimethylchloroaluminum, trimethylaluminum, magnesium chloride, magnesium bromide, titanium tetrachloride, dichlorotitanium bistriflate, biscyclopentadienyltitanium bistriflate, dichlorotitanium bisfluorosulfonate, tin tetrachloride, tin(II) bistriflate, etc. Also, titanium tetrachloride can be used in combination with a catalytic amount of methanesulfonic acid trimethylsilyl ether. The Lewis base is not particularly limited, but specific examples include triethylamine, tributylamine, ethyldiisopropylamine, tetramethylenediamine, N-ethylpiperidine, diazabicyclo[2,2,0]undecene, diazabicyclo[3,3,0]octane, etc. The combination of the Lewis acid and Lewis base used can be appropriately selected depending on the combination of the compounds to be reacted, and among them, the combination of titanium tetrachloride and triethylamine is preferred.

The reaction between the compound in which _X0 in the formula (X) is a halogen atom and the compound represented by the formula (B-1) or the following formula (B-1-1) can be carried out in a solvent. The solvent is not particularly limited as long as it does not affect the Lewis acid used, and specific examples include chlorine-based solvents such as methylene chloride, chloroform, and chlorobenzene, and hydrocarbon-based solvents such as benzene, toluene, hexane, and cyclohexane, and these can be used alone or in combination of two or more. In particular, methylene chloride and chlorobenzene are preferred.

The reaction of the compound in which _X0 in the formula (X) is a halogen atom with the compound represented by the formula (B-1) or the following formula (B-1-1) is not particularly limited and can be appropriately selected depending on the reactivity of the reaction raw materials, and can be carried out, for example, at −70° C. to 40° C. for 0.5 to 120 hours.

In addition, the compound in which X ₀ in the formula (X) is a group represented by the formula (A-1) or the formula (A-1-1) can also be synthesized by the following method. For example, a polyalkoxybenzene compound is obtained by reacting an alkoxybenzene with a corresponding tellurium halide, and then a reduction reaction is carried out with a reducing agent such as boron tribromide to obtain a polyphenol compound. A dissociative reactive group is introduced into at least one phenolic hydroxyl group of the obtained polyphenol compound by a known method, thereby obtaining a compound having a group represented by the formula (A-1) or the formula (A-1-1).

In addition, a polyphenol oligomer can be obtained by reacting phenols or thiophenols with the corresponding tellurium halides, and a dissociable reactive group can be introduced into at least one phenolic hydroxyl group of the obtained polyphenol compound by a known method, thereby obtaining a compound having a group represented by the formula (A-1) or (A-1-1).

Furthermore, a polyphenol compound can be obtained by reacting a phenol or a thiophenol with a corresponding tellurium-containing aldehyde or a tellurium-containing ketone in the presence of an acid or base catalyst, and a dissociable reactive group can be introduced into at least one phenolic hydroxyl group of the obtained polyphenol compound by a known method, thereby obtaining a compound having a group represented by the formula (A-1) or the formula (A-1-1).

Although not particularly limited, for example, as described later, tellurium tetrachloride (tellurium (IV) tetrachloride) and a substituted or unsubstituted phenol derivative can be reacted in the presence of a base catalyst to synthesize a compound having a group represented by the formula (A-1) or (A-1-1). That is, the compound in which _X0 in the formula (X) is a group represented by the formula (A-1) or (A-1-1) can also be produced by a production method including a step of synthesizing the compound by reacting tellurium tetrachloride with a substituted or unsubstituted phenol derivative in the presence of a base catalyst.

The tellurium halide is not particularly limited and examples thereof include tellurium(IV) tetrafluoride, tellurium(IV) tetrachloride, tellurium(IV) tetrabromide, tellurium(IV) tetraiodide, etc.

The alkoxybenzenes are not particularly limited, and examples thereof include methoxybenzene, dimethoxybenzene, methylmethoxybenzene, methyldimethoxybenzene, phenylmethoxybenzene, phenyldimethoxybenzene, methoxynaphthalene, dimethoxynaphthalene, ethoxybenzene, diethoxybenzene, methylethoxybenzene, methyldiethoxybenzene, phenylethoxybenzene, phenyldiethoxybenzene, ethoxynaphthalene, and diethoxynaphthalene.

A reaction solvent may be used when producing the polyalkoxybenzene compound. The reaction solvent is not particularly limited as long as the reaction between the alkoxybenzenes used and the corresponding tellurium halide proceeds, but for example, water, methylene chloride, methanol, ethanol, propanol, butanol, tetrahydrofuran, dioxane, dimethylacetamide, N-methylpyrrolidone, or a mixture thereof can be used. The amount of the solvent is not particularly limited, and can be, for example, in the range of 0 to 2000 parts by mass per 100 parts by mass of the reaction raw materials.

When producing the polyphenol compound containing tellurium, the reaction temperature is not particularly limited and can be selected appropriately depending on the reactivity of the reaction raw materials, but it is preferably in the range of 10 to 200°C.

The method for producing the polyalkoxybenzene is not particularly limited, but examples include a method in which the alkoxybenzenes and the corresponding tellurium halides are charged all at once, and a method in which the alkoxybenzenes and the corresponding tellurium halides are added dropwise. After the reaction is completed, in order to remove unreacted raw materials and the like present in the system, the temperature of the reaction vessel can be raised to 130 to 230°C, and volatile matters can be removed at about 1 to 50 mmHg.

The amount of raw materials used in producing the polyalkoxybenzene compound is not particularly limited, but for example, 1 mole to an excess amount of alkoxybenzenes can be used per mole of tellurium halide, and the reaction can be carried out at normal pressure at 20 to 150°C for approximately 20 minutes to 100 hours.

When producing the polyalkoxybenzene compound, the target product can be isolated by a known method after the reaction is completed. The method for isolating the target product is not particularly limited, and examples include a method in which the reaction solution is concentrated, pure water is added to precipitate the reaction product, cooled to room temperature, and then separated by filtration, the resulting solid is filtered and dried, and then separated and purified from the by-products by column chromatography, and the target compound is obtained by distilling off the solvent, filtration, and drying.

The polyphenol compound can be obtained by reducing a polyalkoxybenzene compound. The reduction reaction can be carried out using a reducing agent such as boron tribromide. A reaction solvent may be used when producing the polyphenol compound. The reaction time, reaction temperature, amount of raw materials, and isolation method are not particularly limited as long as the polyphenol compound can be obtained.

A method for introducing a dissociative reactive group into at least one phenolic hydroxyl group of the polyphenol compound can be a known method. For example, a dissociative reactive group can be introduced into at least one phenolic hydroxyl group of the polyphenol compound as follows. Compounds for introducing a dissociative reactive group can be synthesized by known methods or can be easily obtained, and examples thereof include, but are not limited to, activated carboxylic acid derivative compounds such as acid chlorides, acid anhydrides, dicarbonates, alkyl halides, vinyl alkyl ethers, dihydropyrans, and halocarboxylic acid alkyl esters.

For example, the polyphenol compound is dissolved or suspended in an aprotic solvent such as acetone, tetrahydrofuran (THF), propylene glycol monomethyl ether acetate, dimethylacetamide, or N-methylpyrrolidone. Next, a vinyl alkyl ether such as ethyl vinyl ether or dihydropyran is added, and the mixture is reacted at normal pressure at 20 to 60°C for 6 to 72 hours in the presence of an acid catalyst such as pyridinium p-toluenesulfonate. The reaction solution is neutralized with an alkaline compound, added to distilled water to precipitate a white solid, and the separated white solid is washed with distilled water and dried to obtain a compound having a group represented by the formula (A-1) or (A-1-1).

The acid catalyst is not particularly limited, and inorganic acids and organic acids are widely known as well-known acid catalysts. For example, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid, and hydrofluoric acid, organic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, citric acid, fumaric acid, maleic acid, formic acid, p-toluenesulfonic acid, methanesulfonic acid, trifluoroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, naphthalenesulfonic acid, and naphthalenedisulfonic acid, Lewis acids such as zinc chloride, aluminum chloride, iron chloride, and boron trifluoride, and solid acids such as silicotungstic acid, phosphotungstic acid, silicomolybdic acid, and phosphomolybdic acid are included, but are not particularly limited to these. Among these, organic acids and solid acids are preferred from the viewpoint of production, and hydrochloric acid or sulfuric acid is preferably used from the viewpoint of production, such as ease of availability and ease of handling. The acid catalyst may be used alone or in combination of two or more kinds.

Alternatively, a polyphenol compound may be dissolved or suspended in an aprotic solvent such as acetone, THF, propylene glycol monomethyl ether acetate, dimethylacetamide, or N-methylpyrrolidone. Then, an alkyl halide such as ethyl chloromethyl ether or a halocarboxylic acid alkyl ester such as methyladamantyl bromoacetate is added, and the mixture is reacted in the presence of a base catalyst such as potassium carbonate at normal pressure and at 20 to 110°C for 6 to 72 hours. The reaction solution is neutralized with an acid such as hydrochloric acid, and added to distilled water to precipitate a white solid. The separated white solid is then washed with distilled water and dried to obtain a compound having a group represented by the formula (A-1) or (A-1-1).

The base catalyst is not particularly limited and can be appropriately selected from well-known base catalysts. Examples of the base catalyst include inorganic bases such as metal hydrides (alkali metal hydrides such as sodium hydride and potassium hydride), metal alcohol salts (alkaline metal alcohol salts such as sodium methoxide and potassium ethoxide), metal hydroxides (alkali metal or alkaline earth metal hydroxides such as sodium hydroxide and potassium hydroxide), metal carbonates (alkali metal or alkaline earth metal carbonates such as sodium carbonate and potassium carbonate), alkali metal or alkaline earth metal hydrogen carbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate, and organic bases such as amines (e.g., tertiary amines (trialkylamines such as triethylamine, aromatic tertiary amines such as N,N-dimethylaniline, heterocyclic tertiary amines such as 1-methylimidazole), and metal carboxylates (alkali metal acetate or alkaline earth metal salts such as sodium acetate and calcium acetate). From the viewpoint of production, such as ease of availability and ease of handling, sodium carbonate and potassium carbonate are preferred. In addition, one or more types of base catalysts can be used.

It is preferable that the dissociable reactive group has the property of undergoing a chain cleavage reaction in the presence of acid, in order to enable pattern formation with even higher sensitivity and resolution.

[resin]
The resin according to this embodiment includes a structural unit derived from the compound represented by the formula (X) according to the embodiment described above. In other words, the resin according to this embodiment can be a resin obtained by using the compound represented by the formula (X) as a monomer. The resin is not particularly limited as long as it includes a structural unit derived from the compound represented by the formula (X), and can be obtained, for example, by reacting the compound represented by the formula (X) with a reactive compound.

As the reactive compound, any known compound can be used without particular limitation as long as it can oligomerize or polymerize the compound represented by formula (X). Specific examples thereof include, but are not limited to, aldehydes, ketones, carboxylic acids, carboxylic acid halides, halogen-containing compounds, amino compounds, imino compounds, isocyanates, and unsaturated hydrocarbon group-containing compounds.

In addition, it is preferable that the resin according to this embodiment contains a structural unit represented by the following formula (B1-M) in order to have high heat resistance, high refractive index, and high solubility.

In formula (B1-M), each R ³ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; s is an integer of 0 to 3; n ³ is 0 to (4+2×s); Y, P ⁰ , q, and v are the same as those defined in formula (X); R ⁴ is a single bond or a group represented by the following formula (5).

(In formula (5), R ⁵ is a substituted or unsubstituted linear alkylene group having 1 to 20 carbon atoms, a branched alkylene group having 3 to 20 carbon atoms, or a cyclic alkylene group having 3 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and each R ^5' is independently any group of the following formula (5').)

(In formula (5'), * indicates connection to ^R5 .)

In ^R5 of the formula (5), examples of the linear alkylene group having 1 to 20 carbon atoms include, but are not limited to, a methylene group, an ethylene group, an n-propylene group, an n-butylene group, an n-pentylene group, an n-hexylene group, etc. Examples of the branched alkylene group having 3 to 20 carbon atoms include, but are not limited to, an isopropylene group, an isobutylene group, a tert-butylene group, a neopentylene group, a 2-hexylene group, etc. Examples of the cyclic alkylene group having 3 to 20 carbon atoms include, but are not limited to, a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cyclooctylene group, a cyclodecylene group, an adamantylene group, etc. Examples of the arylene group having 6 to 20 carbon atoms include, but are not limited to, a phenylene group, a naphthylene group, a biphenylene group, a fluorenylene group, an anthracenylene group, and a pyrenylene group.

In the formula (B1-M), R ⁴ is preferably a group represented by the formula (5) in order to impart high heat resistance and high solubility.

In addition, it is preferable that the resin according to this embodiment contains a structural unit represented by the following formula (B2-M') in order to further improve heat resistance.

(In formula (B2-M'), each R ³ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; s is an integer of 0 to 3, and n ³ is 0 to (4+2×s); Y, P ⁰ , q, and v are the same as defined in formula (X); R ⁶ is a substituted or unsubstituted linear, branched, or cyclic trivalent aliphatic group having 1 to 20 carbon atoms, or a substituted or unsubstituted trivalent aromatic group having 6 to 20 carbon atoms; and each R ^6' is independently a group represented by the following formula (6').)

(In formula (6'), * indicates connection to ^R6 .)

In R ⁶ of the formula (B2-M'), examples of the linear trivalent aliphatic group having 1 to 20 carbon atoms include, but are not limited to, a methanetriyl group, an ethanetriyl group, an n-propanetriyl group, an n-butanetriyl group, an n-pentanetriyl group, an n-hexanetriyl group, etc. Examples of the branched trivalent aliphatic group having 3 to 20 carbon atoms include, but are not limited to, an isopropanetriyl group, an isobutanetriyl group, a tert-butanetriyl group, a neopentanetriyl group, an 2-hexanetriyl group, etc. Examples of the cyclic trivalent aliphatic group having 3 to 20 carbon atoms include, but are not limited to, a cyclopropanetriyl group, a cyclobutanetriyl group, a cyclopentanetriyl group, a cyclohexanetriyl group, a cyclooctanetriyl group, a cyclodecanetriyl group, an adamantanetriyl group, etc. Examples of the trivalent aromatic group having 6 to 20 carbon atoms include, but are not limited to, a benzenetriyl group, a naphthalenetriyl group, a biphenyltriyl group, a fluorenetriyl group, an anthracenetriyl group, and a pyrenetriyl group.

In addition, it is preferable that the resin according to this embodiment contains a structural unit represented by the following formula (C1) in order to have both high heat resistance and a high refractive index.

(In formula (C1), each R ⁷ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; r is an integer of 0 to 3; and n ⁷ is an integer of 2 to (4+2×r). Y, P ⁰ , q, and v are each defined as in formula (X).)

In addition, in the resin containing each of the above-mentioned structural units, the respective substituents may be different between the structural units. For example, R5 in the case where ^R4 in the formula (B1-M) is a group represented by the formula ( ⁵ ), and ^R6 in the formula (B2-M') may be the same or different between the respective structural units.

Specific examples of the structural unit represented by the formula (B1-M) include the following structural units:

Specific examples of the structural unit represented by the formula (B2-M') include the following structural units:

Specific examples of the structural unit represented by formula (C1) include the following structural units:

[Method for purifying compounds or resins]
The compound or resin of this embodiment can be purified by a purification method including the following steps. That is, the purification method includes a step of dissolving the compound represented by formula (X) according to this embodiment or a resin containing a structural unit derived from the compound in a solvent containing an organic solvent that is not miscible with water to obtain a solution (A), and a first extraction step of contacting the obtained solution (A) with an acidic aqueous solution to extract impurities in the compound or the resin. According to the purification method of this embodiment, the content of various metals that may be contained as impurities in the compound or resin having the above-mentioned specific structure can be effectively reduced.

The metal content contained in solution (A) containing a compound represented by formula (X) or a resin containing a structural unit derived from the compound is transferred to the aqueous phase, and the organic phase and the aqueous phase are separated to obtain a compound represented by formula (X) or a resin containing a structural unit derived from the compound with a reduced metal content.

The compound represented by formula (X) or the resin containing a structural unit derived from the compound used in the purification method of this embodiment may be used alone, or two or more types may be mixed. In addition, the compound represented by formula (X) or the resin containing a structural unit derived from the compound may be applied to the purification method of this embodiment together with various surfactants, various crosslinking agents, various acid generators, and various stabilizers.

The "organic solvent that is not miscible with water at any ratio" used in the purification method of this embodiment means an organic solvent that is not uniformly miscible with water at any ratio. Although there are no particular limitations on such organic solvents, organic solvents that can be safely applied to semiconductor manufacturing processes are preferred, and specifically, organic solvents whose solubility in water at room temperature is less than 30%, more preferably less than 20%, and particularly preferably less than 10% are preferred. The amount of the organic solvent used is preferably 1 to 100 parts by mass per 100 parts by mass of the compound represented by formula (X) or the resin containing a structural unit derived from the compound used.

Specific examples of organic solvents that are not arbitrarily miscible with water include, but are not limited to, ethers such as diethyl ether and diisopropyl ether; esters such as ethyl acetate, n-butyl acetate, and isoamyl acetate; ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl isobutyl ketone, cyclohexanone (CHN), cyclopentanone, 2-heptanone, and 2-pentanone; glycol ether acetates such as ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), and propylene glycol monoethyl ether acetate; aliphatic hydrocarbons such as n-hexane and n-heptane; aromatic hydrocarbons such as toluene and xylene; and halogenated hydrocarbons such as methylene chloride and chloroform. Among these, one or more organic solvents selected from the group consisting of toluene, 2-heptanone, cyclohexanone, cyclopentanone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, ethyl acetate, etc. are preferred, methyl isobutyl ketone, ethyl acetate, cyclohexanone, propylene glycol monomethyl ether acetate are more preferred, and methyl isobutyl ketone and ethyl acetate are even more preferred. Methyl isobutyl ketone, ethyl acetate, etc. have a relatively high saturated solubility of the compound represented by formula (X) or a resin containing a structural unit derived from the compound, and a relatively low boiling point, so that it is possible to reduce the load in the process of industrially distilling off the solvent or removing it by drying. Each of these organic solvents can be used alone, or two or more of them can be mixed and used.

The "acidic aqueous solution" used in the purification method of this embodiment is appropriately selected from among aqueous solutions in which a commonly known organic compound or inorganic compound is dissolved in water. The acidic aqueous solution is not limited to the following, but examples thereof include mineral acid aqueous solutions in which a mineral acid such as hydrochloric acid, sulfuric acid, nitric acid, or phosphoric acid is dissolved in water, or organic acid aqueous solutions in which an organic acid such as acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, tartaric acid, citric acid, methanesulfonic acid, phenolsulfonic acid, p-toluenesulfonic acid, or trifluoroacetic acid is dissolved in water. These acidic aqueous solutions can be used alone or in combination of two or more. Among these acidic aqueous solutions, one or more mineral acid aqueous solutions selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, or one or more organic acid aqueous solutions selected from the group consisting of acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, tartaric acid, citric acid, methanesulfonic acid, phenolsulfonic acid, p-toluenesulfonic acid, and trifluoroacetic acid are preferred, and aqueous solutions of sulfuric acid, nitric acid, and carboxylic acids such as acetic acid, oxalic acid, tartaric acid, and citric acid are more preferred, and aqueous solutions of oxalic acid are even more preferred. Polycarboxylic acids such as oxalic acid, tartaric acid, and citric acid are coordinated to metal ions, and a chelating effect is generated, so that it is considered that there is a tendency to more effectively remove metals. In addition, it is preferable to use water with a low metal content, such as ion-exchanged water, in accordance with the purpose of the purification method of this embodiment.

Although the pH of the acidic aqueous solution used in the purification method of this embodiment is not particularly limited, it is preferable to adjust the acidity of the aqueous solution taking into consideration the effect on the compound represented by formula (X) or the resin containing a structural unit derived from said compound. Typically, the pH range of the acidic aqueous solution is about 0 to 5, and preferably about 0 to 3.

The amount of the acidic aqueous solution used in the purification method of this embodiment is not particularly limited, but it is preferable to adjust the amount used from the viewpoint of reducing the number of extractions for metal removal and from the viewpoint of ensuring operability by taking into account the total liquid volume. From the above viewpoints, the amount of the acidic aqueous solution used is preferably 10 to 200 parts by mass, more preferably 20 to 100 parts by mass, per 100 parts by mass of the solution (A).

In the purification method of this embodiment, the acidic aqueous solution as described above is contacted with solution (A) containing one or more compounds selected from the compound represented by formula (X) and resins containing structural units derived from the compound, and an organic solvent that is arbitrarily immiscible with water, thereby making it possible to extract metal components from the compound or resin in solution (A).

When an organic solvent that is arbitrarily miscible with water is included, the amount of the compound represented by formula (X) or the resin containing a structural unit derived from the compound can be increased, and the liquid separation property is improved, and purification tends to be performed with high kettle efficiency. The method of adding the organic solvent that is arbitrarily miscible with water is not particularly limited. For example, any of the following methods may be used: adding the organic solvent to a solution containing the organic solvent in advance, adding the organic solvent to water or an acidic aqueous solution in advance, or adding the organic solvent after contacting the solution containing the organic solvent with water or an acidic aqueous solution. Among these, the method of adding the organic solvent to a solution containing the organic solvent in advance is preferred in terms of ease of operation and ease of management of the amount of the charge.

The organic solvent that is miscible with water and used in the purification method of this embodiment is not particularly limited, but is preferably an organic solvent that can be safely applied to a semiconductor manufacturing process. The amount of the organic solvent that is miscible with water used is not particularly limited as long as the solution phase and the aqueous phase are separated, but is preferably 0.1 to 100 parts by mass, more preferably 0.1 to 50 parts by mass, and even more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the compound represented by formula (X) or the resin containing a structural unit derived from the compound.

Specific examples of organic solvents that are optionally miscible with water and used in the purification method of this embodiment include, but are not limited to, ethers such as tetrahydrofuran and 1,3-dioxolane; alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone and N-methylpyrrolidone; and aliphatic hydrocarbons such as glycol ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether (PGME), and propylene glycol monoethyl ether. Among these, N-methylpyrrolidone, propylene glycol monomethyl ether, and the like are preferred, and N-methylpyrrolidone and propylene glycol monomethyl ether are more preferred. Each of these solvents can be used alone, or two or more of them can be mixed and used.

In the purification method of this embodiment, the temperature when the solution (A) comes into contact with the acidic aqueous solution, i.e., when the extraction process is performed, is preferably in the range of 20 to 90°C, more preferably 30 to 80°C. The extraction operation is not particularly limited, but for example, the solution (A) and the acidic aqueous solution are thoroughly mixed by stirring or the like, and then the resulting mixed solution is allowed to stand. As a result, the metal content contained in the solution (A) containing one or more selected from the compound represented by formula (X) and the resin containing a structural unit derived from the compound and an organic solvent is transferred to the aqueous phase. In addition, this operation reduces the acidity of the solution (A), and can suppress the deterioration of the compound represented by formula (X) or the resin containing a structural unit derived from the compound.

By allowing the mixed solution to stand, the solution is separated into a solution phase containing one or more compounds selected from the compound represented by formula (X) and a resin containing a structural unit derived from the compound, an organic solvent, and an aqueous phase, and the solution phase containing one or more compounds selected from the compound represented by formula (X) and a resin containing a structural unit derived from the compound, and an organic solvent can be recovered by decantation or the like. The time for allowing the mixed solution to stand is not particularly limited, but it is preferable to adjust the time for allowing the mixed solution to stand from the viewpoint of improving the separation of the solution phase containing the organic solvent and the aqueous phase. Usually, the time for allowing the mixed solution to stand is 1 minute or more, preferably 10 minutes or more, and more preferably 30 minutes or more. The extraction process may be performed only once, but it is also effective to repeat the operations of mixing, allowing the mixed solution to stand, and separating the mixed solution to stand multiple times.

In the purification method of this embodiment, it is preferable to further include a step (second extraction step) of contacting the solution phase containing the compound or the resin with water after the first extraction step to extract impurities in the compound or the resin.

Specifically, for example, after the extraction treatment is performed using an acidic aqueous solution, the solution phase containing one or more compounds selected from the compound represented by formula (X) and a resin containing a structural unit derived from the compound and an organic solvent extracted and recovered from the aqueous solution is preferably subjected to an extraction treatment with water. The extraction treatment with water is not particularly limited, but can be performed, for example, by thoroughly mixing the solution phase and water by stirring or the like, and then allowing the resulting mixed solution to stand. The mixed solution after standing is separated into a solution phase containing one or more compounds selected from the compound represented by formula (X) and a resin containing a structural unit derived from the compound and an organic solvent, and an aqueous phase, so that the solution phase containing one or more compounds selected from the compound represented by formula (X) and a resin containing a structural unit derived from the compound and an organic solvent can be recovered by decantation or the like.

In addition, in accordance with the purpose of this embodiment, the water used here is preferably water with a low metal content, such as ion-exchanged water. The extraction process may be performed only once, but it is also effective to repeat the operations of mixing, leaving, and separating multiple times. In addition, the ratio of both substances used in the extraction process, and the conditions such as temperature and time are not particularly limited, but may be the same as in the case of the contact treatment with the acidic aqueous solution described above.

Water that may be mixed into the solution thus obtained containing one or more selected from the compound represented by formula (X) and the resin containing a structural unit derived from the compound and an organic solvent can be easily removed by performing an operation such as vacuum distillation. In addition, if necessary, an organic solvent can be added to the solution to adjust the concentration of the compound represented by formula (X) or the resin containing a structural unit derived from the compound to an arbitrary concentration.

The method for isolating one or more compounds selected from the compound represented by formula (X) and resins containing structural units derived from the compound from a solution containing one or more compounds selected from the compound represented by formula (X) and resins containing structural units derived from the compound and an organic solvent is not particularly limited, and can be performed by known methods such as removal under reduced pressure, separation by reprecipitation, and combinations thereof. If necessary, known processes such as concentration, filtration, centrifugation, and drying can be performed.

[Composition]
The composition according to the present embodiment contains the compound or resin according to the present embodiment. The composition according to the present embodiment may be, for example, a material for lithography, a material composition for lithography, a composition for forming a resist underlayer film, a composition for forming an optical article, or the like.
[Lithography Materials]
The lithography material according to this embodiment contains the compound or resin according to this embodiment. The lithography material according to this embodiment is a material that can be used in lithography technology, and is not particularly limited as long as it contains the compound or resin according to this embodiment. For example, it can be used as a lithography material composition together with a solvent or the like, and further can be used for resist applications (i.e., resist composition), intermediate layer formation applications (i.e., intermediate layer formation composition), underlayer film formation applications (i.e., underlayer film formation composition), etc. The lithography material according to this embodiment may contain the compound and resin according to this embodiment.

The lithography material according to this embodiment can be used for resist compositions that can reduce defects in the film (thin film formation), have good storage stability, are highly sensitive, have a high refractive index and transparency in a specific wavelength region, and can provide a good resist pattern shape. The lithography material according to this embodiment contains the tellurium-containing compound or resin according to this embodiment, and is therefore expected to have a sensitizing effect, especially in EUV lithography. Tellurium has the second highest sensitizing effect after xenon among all elements. The lithography material according to this embodiment may be solvent-free.

[Lithography material composition]
The lithography material composition according to the present embodiment includes the lithography material according to the present embodiment and a solvent, and is capable of reducing defects in a film (forming a thin film), exhibiting good storage stability, high sensitivity, a high refractive index and transparency in a specific wavelength region, and capable of imparting a good resist pattern shape.

(Physical properties of lithography material composition)
The lithography material of this embodiment can be used for resist applications as described above, and an amorphous film can be formed by a known method such as spin coating. In addition, depending on the type of developer used, either a positive resist pattern or a negative resist pattern can be produced. Hereinafter, a case where a lithography material composition containing the lithography material of this embodiment is used for resist applications (as a resist composition) will be described.

In the case where the lithography material composition of this embodiment is a positive resist pattern, the dissolution rate of the amorphous film formed by spin-coating the lithography material composition of this embodiment in a developer at 23°C is preferably 5 Å/sec or less, more preferably 0.05 to 5 Å/sec, and even more preferably 0.0005 to 5 Å/sec. If the dissolution rate is 5 Å/sec or less, the resist can be insoluble in the developer. If the dissolution rate is 0.0005 Å/sec or more, the resolution may be improved. This is presumably because the contrast at the interface between the exposed portion that dissolves in the developer and the unexposed portion that does not dissolve in the developer increases due to the change in solubility before and after exposure of the compound represented by formula (X) or the resin containing a structural unit derived from the compound. In addition, there is an effect of reducing line edge roughness and reducing defects.

In the case where the lithography material composition of this embodiment is a negative resist pattern, the dissolution rate of the amorphous film formed by spin-coating the lithography material composition of this embodiment in a developer at 23°C is preferably 10 Å/sec or more. If the dissolution rate is 10 Å/sec or more, the film is easily soluble in the developer and is more suitable for resist. In addition, if the dissolution rate is 10 Å/sec or more, the resolution may be improved. This is presumably because the micro surface portion of the compound represented by formula (X) or the resin containing a structural unit derived from the compound dissolves, reducing line edge roughness. There is also an effect of reducing defects. The dissolution rate can be determined by immersing the amorphous film in a developer for a predetermined time at 23°C and measuring the film thickness before and after the immersion by a known method such as visual observation, an ellipsometer, or a QCM method.

When the lithography material composition of this embodiment is used for a positive resist pattern, the dissolution rate in a developer at 23°C of the portion of the amorphous film formed by spin-coating the lithography material composition of this embodiment that is exposed to radiation such as KrF excimer laser, extreme ultraviolet light, electron beam, or X-ray is preferably 10 Å/sec or more. If the dissolution rate is 10 Å/sec or more, the film is easily soluble in a developer and is more suitable for use as a resist. In addition, if the dissolution rate is 10 Å/sec or more, the resolution may be improved. This is presumably because the micro surface portion of the resin containing the compound represented by formula (X) or a structural unit derived from the compound dissolves, reducing line edge roughness. There is also an effect of reducing defects.

When the lithography material composition of this embodiment is used for a negative resist pattern, the dissolution rate of the portion of the amorphous film formed by spin-coating the lithography material composition of this embodiment exposed to radiation such as KrF excimer laser, extreme ultraviolet light, electron beam, or X-ray in a developer at 23°C is preferably 5 Å/sec or less, more preferably 0.05 to 5 Å/sec, and even more preferably 0.0005 to 5 Å/sec. If the dissolution rate is 5 Å/sec or less, the resist can be insoluble in the developer. If the dissolution rate is 0.0005 Å/sec or more, the resolution may be improved. This is presumably because the contrast at the interface between the unexposed portion that dissolves in the developer and the exposed portion that does not dissolve in the developer increases due to the change in solubility before and after exposure of the compound represented by formula (X) or the resin containing a structural unit derived from the compound. There is also an effect of reducing line edge roughness and defects.

Other Components of the Lithographic Material Composition
The lithography material composition of the present embodiment contains, as a solid component, a compound represented by formula (X) or a resin containing a structural unit derived from the compound. The lithography material composition of the present embodiment further contains a solvent in addition to the compound represented by formula (X) or the resin containing a structural unit derived from the compound.

The solvent used in the lithography material composition of this embodiment is not particularly limited, but may be, for example, ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, and ethylene glycol mono-n-butyl ether acetate; ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate (PGMEA), propylene glycol mono-n-propyl ether acetate, and propylene glycol mono-n-butyl ether acetate; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl ether; methyl lactate, ethyl lactate, n-propyl lactate, n-propyl lactate, lactic acid esters such as butyl and n-amyl lactate; aliphatic carboxylic acid esters such as methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, n-amyl acetate, n-hexyl acetate, methyl propionate, and ethyl propionate; methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 3-methoxy-2-methylpropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methoxy-3-methyl Examples of the solvent include other esters such as butyl propionate, butyl 3-methoxy-3-methylbutyrate, methyl acetoacetate, methyl pyruvate, and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclopentanone (CPN), and cyclohexanone (CHN); amides such as N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, and N-methylpyrrolidone; lactones such as γ-lactone, etc. These solvents can be used alone or in combination.

The solvent used in the lithography material composition of this embodiment is preferably a safe solvent, more preferably at least one selected from PGMEA, PGME, CHN, CPN, 2-heptanone, anisole, butyl acetate, ethyl propionate and ethyl lactate, and even more preferably at least one selected from PGMEA, PGME and CHN.

In the lithography material composition of this embodiment, the relationship between the amount of solid components and the amount of solvent is not particularly limited, but it is preferable that the solid components be 1 to 80% by mass and the solvent be 20 to 99% by mass, more preferably 1 to 50% by mass and the solvent be 50 to 99% by mass, even more preferably 2 to 40% by mass and the solvent be 60 to 98% by mass, and particularly preferably 2 to 10% by mass and the solvent be 90 to 98% by mass.

The lithography material composition of this embodiment may contain at least one other solid component selected from the group consisting of an acid generator (C), an acid crosslinker (G), an acid diffusion control agent (E) and other components (F).

In the lithography material composition of this embodiment, the content of the compound represented by formula (X) and the resin containing a structural unit derived from the compound is not particularly limited, but is preferably 50 to 99.4% by mass of the total mass of the solid components (the sum of the compound represented by formula (X) and the resin containing a structural unit derived from the compound, the acid generator (C), the acid crosslinker (G), the acid diffusion controller (E), and other components (F) that are optionally used, the same below), more preferably 55 to 90% by mass, even more preferably 60 to 80% by mass, and particularly preferably 60 to 70% by mass. With this content, the resolution is further improved and the line edge roughness (LER) is further reduced.

(Acid Generator (C))
The lithography material composition of the present embodiment preferably contains one or more acid generators (C) that generate an acid directly or indirectly when irradiated with any one of radiation selected from visible light, ultraviolet light, an excimer laser, an electron beam, extreme ultraviolet light (EUV), X-rays, and an ion beam.

In this case, in the lithography material composition of this embodiment, the content of the acid generator (C) is preferably 0.001 to 49 mass % of the total mass of the solid components, more preferably 1 to 40 mass %, even more preferably 3 to 30 mass %, and particularly preferably 10 to 25 mass %. By using the acid generator (C) within the above content range, a pattern profile with even higher sensitivity and even lower edge roughness can be obtained.

In the lithography material composition of this embodiment, the method of generating the acid is not limited as long as an acid is generated in the system. If an excimer laser is used instead of ultraviolet rays such as g-rays or i-rays, finer processing is possible, and if an electron beam, extreme ultraviolet rays, X-rays, or ion beams are used as high-energy rays, even finer processing is possible.

The acid generator (C) is not particularly limited, and examples thereof include the compounds disclosed in International Publication No. 2017/033943. As the acid generator (C), an acid generator having an aromatic ring is preferable, an acid generator having a sulfonate ion having an aryl group is more preferable, and diphenyltrimethylphenylsulfonium p-toluenesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium trifluoromethanesulfonate, and triphenylsulfonium nonafluoromethanesulfonate are particularly preferable. By using the acid generator, line edge roughness can be reduced.

In addition, the lithography material composition of this embodiment preferably further contains a diazonaphthoquinone photoactive compound as an acid generator. The diazonaphthoquinone photoactive compound is a diazonaphthoquinone substance including a polymeric and non-polymeric diazonaphthoquinone photoactive compound, and is not particularly limited as long as it is generally used as a photosensitive component in a positive resist composition, and one or more types can be arbitrarily selected and used. Among these, from the viewpoint of low roughness and solubility, a non-polymeric diazonaphthoquinone photoactive compound is preferable, and a low molecular weight compound having a molecular weight of 1500 or less is more preferable, a molecular weight of 1200 or less is even more preferable, and a molecular weight of 1000 or less is particularly preferable. A preferred specific example of such a non-polymeric diazonaphthoquinone photoactive compound includes the non-polymeric diazonaphthoquinone photoactive compound disclosed in International Publication No. 2016/158881. The acid generator (C) can be used alone or in two or more types.

(Acid Crosslinker (G))
The lithography material composition of the present embodiment preferably contains one or more acid crosslinkers (G) when used as a negative resist material or as an additive for increasing the strength of a pattern in a positive resist material. The acid crosslinker (G) is a compound that can intramolecularly or intermolecularly crosslink a compound represented by the formula (X) or a resin containing a structural unit derived from the compound in the presence of an acid generated from the acid generator (C). Such an acid crosslinker (G) is not particularly limited, but examples thereof include compounds having one or more groups (hereinafter referred to as "crosslinkable groups") that can crosslink a compound represented by the formula (X) or a resin containing a structural unit derived from the compound.

Specific examples of such crosslinkable groups include, but are not limited to, (i) hydroxyalkyl groups such as hydroxy (alkyl group having 1 to 6 carbon atoms), alkoxy (alkyl group having 1 to 6 carbon atoms) having 1 to 6 carbon atoms, and acetoxy (alkyl group having 1 to 6 carbon atoms), or groups derived therefrom; (ii) carbonyl groups such as formyl group and carboxy (alkyl group having 1 to 6 carbon atoms), or groups derived therefrom; (iii) dimethylaminomethyl group, diethylaminomethyl group, dimethylolaminomethyl group, di ... Examples of the crosslinkable group of the acid crosslinking agent (G) include nitrogen-containing groups such as ethylolaminomethyl and morpholinomethyl groups; (iv) glycidyl group-containing groups such as glycidyl ether, glycidyl ester and glycidylamino groups; (v) groups derived from aromatic groups such as allyloxy (alkyl groups having 1 to 6 carbon atoms) and aralkyloxy (alkyl groups having 1 to 6 carbon atoms) having 1 to 6 carbon atoms, such as benzyloxymethyl and benzoyloxymethyl groups; and (vi) polymerizable multiple bond-containing groups such as vinyl and isopropenyl groups. As the crosslinkable group of the acid crosslinking agent (G), hydroxyalkyl groups and alkoxyalkyl groups are preferred, with alkoxymethyl groups being particularly preferred.

The acid crosslinking agent (G) having a crosslinkable group is not particularly limited, but examples thereof include (i) methylol group-containing compounds such as methylol group-containing melamine compounds, methylol group-containing benzoguanamine compounds, methylol group-containing urea compounds, methylol group-containing glycoluril compounds, and methylol group-containing phenolic compounds; (ii) alkoxyalkyl group-containing compounds such as alkoxyalkyl group-containing melamine compounds, alkoxyalkyl group-containing benzoguanamine compounds, alkoxyalkyl group-containing urea compounds, alkoxyalkyl group-containing glycoluril compounds, and alkoxyalkyl group-containing phenolic compounds; (iii) carboxymethyl group-containing compounds such as carboxymethyl group-containing melamine compounds, carboxymethyl group-containing benzoguanamine compounds, carboxymethyl group-containing urea compounds, carboxymethyl group-containing glycoluril compounds, and carboxymethyl group-containing phenolic compounds; and (iv) epoxy compounds such as bisphenol A-based epoxy compounds, bisphenol F-based epoxy compounds, bisphenol S-based epoxy compounds, novolac resin-based epoxy compounds, resol resin-based epoxy compounds, and poly(hydroxystyrene)-based epoxy compounds.

As the acid crosslinking agent (G), compounds having a phenolic hydroxyl group, and compounds and resins in which the crosslinkable group is introduced into the acidic functional group in an alkali-soluble resin to impart crosslinking properties can be used. In this case, the introduction rate of the crosslinkable group is not particularly limited, and is adjusted to, for example, 5 to 100 mol%, preferably 10 to 60 mol%, and more preferably 15 to 40 mol% based on the total acidic functional groups in the compound having a phenolic hydroxyl group and the alkali-soluble resin. This range is preferable because it allows the crosslinking reaction to occur sufficiently, avoiding a decrease in the residual film rate, and avoids swelling and meandering of the pattern.

In the lithography material composition of this embodiment, the acid crosslinker (G) is preferably an alkoxyalkylated urea compound or a resin thereof, or an alkoxyalkylated glycoluril compound or a resin thereof (acid crosslinker (G1)), a phenol derivative having 1 to 6 benzene rings in the molecule and having two or more hydroxyalkyl groups or alkoxyalkyl groups throughout the molecule, with the hydroxyalkyl groups or alkoxyalkyl groups bonded to any of the benzene rings (acid crosslinker (G2)), or a compound having at least one α-hydroxyisopropyl group (acid crosslinker (G3)). For example, the compounds disclosed in WO 2017/033943 can be mentioned.

In the lithography material composition of this embodiment, the content of the acid crosslinker (G) is preferably 0.5 to 49 mass% of the total mass of the solid components, more preferably 0.5 to 40 mass%, even more preferably 1 to 30 mass%, and particularly preferably 2 to 20 mass%. A content ratio of the acid crosslinker (G) of 0.5 mass% or more is preferable because it improves the effect of suppressing the solubility of the resist film in an alkaline developer and can suppress a decrease in the remaining film rate and the occurrence of swelling and meandering of the pattern, while a content ratio of 49 mass% or less is preferable because it can suppress a decrease in the heat resistance of the resist.

In addition, the content of at least one compound selected from the acid crosslinker (G1), the acid crosslinker (G2), and the acid crosslinker (G3) in the acid crosslinker (G) is not particularly limited, and can be in various ranges depending on factors such as the type of substrate used when forming the resist pattern.

(Acid Diffusion Controller (E))
The lithography material composition of this embodiment may contain an acid diffusion controller (E) that has the effect of controlling the diffusion of the acid generated from the acid generator by radiation exposure in the resist film, thereby preventing undesirable chemical reactions in unexposed areas. By using such an acid diffusion controller (E), the storage stability of the lithography material composition is improved. In addition, the resolution is further improved, and the line width change of the resist pattern due to the variation of the exposure time before and after radiation exposure can be suppressed, resulting in extremely excellent process stability.

Such an acid diffusion control agent (E) is not particularly limited, and examples thereof include radiolytic basic compounds such as nitrogen atom-containing basic compounds, basic sulfonium compounds, and basic iodonium compounds. Examples of the acid diffusion control agent (E) include the compounds disclosed in International Publication No. 2017/033943. The acid diffusion control agent (E) may be used alone or in combination of two or more.

The content of the acid diffusion control agent (E) is preferably 0.001 to 49% by mass, more preferably 0.01 to 10% by mass, even more preferably 0.01 to 5% by mass, and particularly preferably 0.01 to 3% by mass, of the total mass of the solid components. When the content of the acid diffusion control agent (E) is within the above range, the deterioration of the resolution, pattern shape, dimensional fidelity, etc. can be further suppressed. Furthermore, even if the delay time from electron beam irradiation to heating after radiation irradiation is long, the shape of the upper layer of the pattern does not deteriorate. Furthermore, when the content of the acid diffusion control agent (E) is 10% by mass or less, the deterioration of the sensitivity, developability of the unexposed part, etc. can be prevented. Furthermore, by using such an acid diffusion control agent, the storage stability of the lithography material composition is improved, and the resolution is improved, and the line width change of the resist pattern due to the fluctuation of the delay time before radiation irradiation and the delay time after radiation irradiation can be suppressed, resulting in extremely excellent process stability.

(Other Components (F))
To the lithography material composition of this embodiment, one or more of various additives such as a dissolution promoter, a dissolution controller, a sensitizer, a surfactant, and an organic carboxylic acid or a phosphorus oxo acid or a derivative thereof can be added as other component (F) as necessary within a range that does not impair the object of this embodiment. Examples of other component (F) include the compounds disclosed in WO 2017/033943.

The total content of other components (F) is preferably 0 to 49 mass% of the total mass of the solid components, more preferably 0 to 5 mass%, even more preferably 0 to 1 mass%, and particularly preferably 0 mass%.

In the lithography material composition of the present embodiment, the content of the resin containing the compound represented by formula (X) and a structural unit derived from the compound, the acid generator (C), the acid diffusion controller (E), and the other components (F) (resin containing the compound represented by formula (X) and a structural unit derived from the compound/acid generator (C)/acid diffusion controller (E)/other components (F)) is, in mass % on a solid basis, preferably 50 to 99.4/0.001 to 49/0.001 to 49/0 to 49, more preferably 55 to 90/1 to 40/0.01 to 10/0 to 5, even more preferably 60 to 80/3 to 30/0.01 to 5/0 to 1, and particularly preferably 60 to 70/10 to 25/0.01 to 3/0.
The content of each component is selected from the respective ranges so that the sum of the components is 100% by mass. When the content is within the above range, the performance such as sensitivity, resolution, developability, etc. is further improved.

The method for preparing the lithography material composition of this embodiment is not particularly limited, and examples include a method in which each component is dissolved in a solvent at the time of use to prepare a homogeneous solution, and then, if necessary, filtered using a filter having a pore size of, for example, about 0.2 μm.

The lithography material composition of this embodiment may contain a resin to the extent that the object of the present invention is not impaired. The resin is not particularly limited, and examples thereof include novolac resins, polyvinylphenols, polyacrylic acid, polyvinyl alcohol, styrene-maleic anhydride resins, and polymers containing acrylic acid, vinyl alcohol, or vinylphenol as monomer units, or derivatives thereof. The content of the resin is not particularly limited, and is appropriately adjusted depending on the type of compound represented by formula (X) or the resin containing a structural unit derived from the compound used, but is preferably 30 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 0 parts by mass per 100 parts by mass of the compound.

[Pattern formation method]
When forming a pattern on a substrate using a lithography material, for example, a pattern formation method can be used that includes a film formation step of forming a film on a substrate using the lithography material according to this embodiment or a composition containing the same (hereinafter, these may be collectively referred to as "lithography material, etc."), an exposure step of exposing the film to light, and a development step of developing the film exposed in the exposure step to form a pattern.

For example, when a resist pattern is formed using the lithography material of this embodiment, the method of forming the pattern (resist pattern) is not particularly limited, and a suitable method includes a film formation step of applying a resist composition containing the above-mentioned lithography material onto a substrate to form a film (resist film), an exposure step of exposing the formed film (resist film), and a development step of developing the film (resist film) exposed in the exposure step to form a pattern (resist pattern). The resist pattern of this embodiment can also be formed as an upper layer resist in a multilayer process.

Specific methods for forming a resist pattern include, but are not limited to, the following methods. First, the resist composition is applied to a conventionally known substrate by a coating means such as spin coating, casting coating, or roll coating to form a resist film. The conventionally known substrate is not particularly limited, and examples thereof include substrates for electronic components and those on which a predetermined wiring pattern is formed. More specifically, examples thereof include, but are not limited to, silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and glass substrates. Materials for the wiring pattern include, but are not limited to, copper, aluminum, nickel, and gold. If necessary, an inorganic film or an organic film may be provided on the substrate. Examples of inorganic films include, but are not limited to, inorganic anti-reflective films (inorganic BARC). Examples of organic films include, but are not limited to, organic anti-reflective films (organic BARC). Surface treatment with hexamethylenedisilazane or the like may be performed.

Next, the coated substrate is heated as necessary. The heating conditions vary depending on the composition of the resist composition, etc., but are preferably 20 to 250°C, more preferably 20 to 150°C. Heating is preferable because it may improve the adhesion of the resist to the substrate. Next, the resist film is exposed to any radiation selected from the group consisting of visible light, ultraviolet light, excimer laser, electron beam, extreme ultraviolet light (EUV), X-rays, and ion beams in a desired pattern. The exposure conditions, etc. are appropriately selected depending on the composition of the resist composition, etc.
In the method for forming a resist pattern of this embodiment, in order to stably form a highly accurate fine pattern in the exposure, it is preferable to heat the resist composition after irradiation with radiation. The heating conditions vary depending on the formulation of the resist composition, etc., but are preferably 20 to 250°C, and more preferably 20 to 150°C.

Next, the exposed resist film is developed with a developer to form a predetermined resist pattern. As the developer, it is preferable to select a solvent having a solubility parameter (SP value) close to the compound represented by formula (X) or the resin containing a structural unit derived from the compound to be used, and a polar solvent such as a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, or an ether solvent, a hydrocarbon solvent, or an alkaline aqueous solution can be used. Depending on the type of developer, a positive resist pattern or a negative resist pattern can be produced, but generally, a negative resist pattern is obtained in the case of a polar solvent such as a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, or an ether solvent, or a hydrocarbon solvent, and a positive resist pattern is obtained in the case of an alkaline aqueous solution. Examples of ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, hydrocarbon solvents, and alkaline aqueous solutions include those disclosed in International Publication No. WO 2017/033943.

The solvent may be mixed in a plurality of types, or may be mixed with other solvents or water within the range of performance. However, in order to fully achieve the effects of the present invention, the water content of the developer as a whole is preferably less than 70% by mass, more preferably less than 50% by mass, more preferably less than 30% by mass, even more preferably less than 10% by mass, and particularly preferably substantially free of water. That is, the content of the organic solvent in the developer is not particularly limited, and is preferably 30% by mass or more and 100% by mass or less, more preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and particularly preferably 95% by mass or more and 100% by mass or less.

In particular, a developer containing at least one solvent selected from ketone-based solvents, ester-based solvents, alcohol-based solvents, amide-based solvents, and ether-based solvents is preferred because it improves resist performance such as the resolution and roughness of the resist pattern.

The vapor pressure of the developer is not particularly limited, and is preferably 5 kPa or less at 20°C, more preferably 3 kPa or less, and particularly preferably 2 kPa or less. By setting the vapor pressure of the developer to 5 kPa or less, evaporation of the developer on the substrate or in the developing cup is suppressed, improving the temperature uniformity within the wafer surface, and as a result, improving the dimensional uniformity within the wafer surface. Examples of developers having such a vapor pressure include the developer disclosed in International Publication No. 2017/033943.

If necessary, an appropriate amount of a surfactant can be added to the developer. There are no particular limitations on the surfactant, but for example, ionic or non-ionic fluorine-based or silicon-based surfactants can be used. Examples of these fluorine or silicon-based surfactants include those described in JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, U.S. Pat. Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, and 5,824,451. Preferably, they are nonionic surfactants. The non-ionic surfactant is not particularly limited, but it is more preferable to use a fluorine-based surfactant or a silicon-based surfactant.

The amount of surfactant used is usually 0.001 to 5 mass %, preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %, relative to the total amount of the developer.

Examples of development methods that can be used include immersing the substrate in a tank filled with developer for a certain period of time (dip method), piling up developer on the substrate surface by surface tension and leaving it still for a certain period of time (paddle method), spraying developer onto the substrate surface (spray method), and continuously dispensing developer while scanning a developer dispensing nozzle at a constant speed onto a substrate rotating at a constant speed (dynamic dispense method). There are no particular restrictions on the time for developing the pattern, but it is preferably 10 to 90 seconds.

After the development step, a step of stopping the development while replacing the solvent with another solvent may be carried out.

After development, it is preferable to include a step of rinsing with a rinsing solution containing an organic solvent.

The rinse liquid used in the rinse step after development is not particularly limited as long as it does not dissolve the resist pattern hardened by crosslinking, and a solution containing a general organic solvent or water can be used. As the rinse liquid, it is preferable to use a rinse liquid containing at least one organic solvent selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, and an ether solvent. More preferably, after development, a step of cleaning is performed using a rinse liquid containing at least one organic solvent selected from the group consisting of a ketone solvent, an ester solvent, an alcohol solvent, and an amide solvent. Even more preferably, after development, a step of cleaning is performed using a rinse liquid containing an alcohol solvent or an ester solvent. Even more preferably, after development, a step of cleaning is performed using a rinse liquid containing a monohydric alcohol. Particularly preferably, after development, a step of cleaning is performed using a rinse liquid containing a monohydric alcohol having 5 or more carbon atoms. There is no particular limit to the time for rinsing the pattern, but it is preferably 10 to 90 seconds.

Here, the monohydric alcohol used in the rinsing process after development is not particularly limited, but examples include linear, branched, and cyclic monohydric alcohols. Specifically, 1-butanol, 2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 4-methyl-2-pentanol, 1-heptanol, 1-octanol, 2-hexanol, cyclopentanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, and 4-octanol can be used. Particularly preferred monohydric alcohols having 5 or more carbon atoms include 1-hexanol, 2-hexanol, 4-methyl-2-pentanol, 1-pentanol, and 3-methyl-1-butanol.

The above components may be mixed in combination or may be mixed with organic solvents other than those mentioned above.

The water content in the rinse solution is not particularly limited, but is preferably 10% by weight or less, more preferably 5% by weight or less, and particularly preferably 3% by weight or less. By keeping the water content at 10% by weight or less, better development characteristics can be obtained.

The vapor pressure of the rinse liquid used after development is preferably 0.05 kPa or more and 5 kPa or less, more preferably 0.1 kPa or more and 5 kPa or less, and even more preferably 0.12 kPa or more and 3 kPa or less at 20°C. By setting the vapor pressure of the rinse liquid to 0.05 kPa or more and 5 kPa or less, the temperature uniformity within the wafer surface is further improved, and swelling caused by the penetration of the rinse liquid is further suppressed, resulting in improved dimensional uniformity within the wafer surface.

An appropriate amount of surfactant can also be added to the rinse solution.

In the rinsing process, the developed wafer is washed with a rinse solution containing the organic solvent. The method of washing is not particularly limited, but may be, for example, a method of continuously applying rinse solution onto a substrate rotating at a constant speed (spin coating method), a method of immersing a substrate in a tank filled with rinse solution for a certain period of time (dip method), or a method of spraying rinse solution onto the substrate surface (spray method). Among these, it is preferable to wash the substrate using the spin coating method, rotate the substrate at a rotation speed of 2000 rpm to 4000 rpm after washing, and remove the rinse solution from the substrate.

After forming the resist pattern, the patterned wiring board is obtained by etching. The etching method can be a known method such as dry etching using plasma gas or wet etching using an alkaline solution, cupric chloride solution, ferric chloride solution, etc.

After forming the resist pattern, plating can be performed. The plating method is not particularly limited, but examples include copper plating, solder plating, nickel plating, and gold plating.

The remaining resist pattern after etching can be peeled off with an organic solvent. The organic solvent is not particularly limited, but examples thereof include PGMEA (propylene glycol monomethyl ether acetate), PGME (propylene glycol monomethyl ether), and EL (ethyl lactate). The peeling method is not particularly limited, but examples thereof include an immersion method and a spray method. The wiring board on which the resist pattern is formed may be a multilayer wiring board and may have a small diameter through hole.

In this embodiment, the wiring board can also be formed by a method in which a resist pattern is formed, a metal is evaporated in a vacuum, and then the resist pattern is dissolved in a solution, i.e., a lift-off method.

[Composition for forming resist underlayer film, underlayer film for lithography, and method for forming pattern]
(First embodiment)
<Composition for forming resist underlayer film>
The composition for forming a resist underlayer film according to the first embodiment of the present invention is a composition for forming a resist underlayer film, which contains the compound or resin according to this embodiment and a silicon-containing compound (e.g., hydrolyzable organosilane, its hydrolysate, or its hydrolysis condensate). The composition for forming a resist underlayer film according to this embodiment has a relatively high carbon concentration, a relatively low oxygen concentration, high heat resistance, and high solvent solubility. Therefore, the rectangularity of the pattern is excellent. In addition, it is possible to reduce film defects (thin film formation), has good storage stability, has high sensitivity, a high refractive index and transparency in a specific wavelength region, and can impart a good resist pattern shape.

The resist underlayer film forming composition of this embodiment can be suitably used, for example, in a multilayer resist method in which a resist underlayer film is further provided between an upper layer resist (photoresist, etc.) and a hard mask or an organic underlayer film. In such a multilayer resist method, for example, a resist underlayer film is formed on an organic underlayer film or hard mask on a substrate by a coating method or the like, and an upper layer resist (for example, photoresist, electron beam resist, EUV resist) is formed on the resist underlayer film. Then, a resist pattern is formed by exposure and development, and the resist underlayer film is dry-etched using the resist pattern to transfer the pattern, and the organic underlayer film is etched to transfer the pattern, and the substrate is processed using the organic underlayer film.

That is, the resist underlayer film (lithography underlayer film) formed using the resist underlayer film forming composition of this embodiment is less likely to cause intermixing with the upper layer resist, and has heat resistance. For example, the etching rate for halogen-based (fluorine-based) etching gas is higher than that of the patterned upper layer resist used as a mask, so that a good rectangular pattern can be obtained. Furthermore, since the resist underlayer film formed using the resist underlayer film forming composition of this embodiment has high resistance to oxygen-based etching gas, it can function as a good mask when patterning a layer provided on a substrate such as a hard mask. The resist underlayer film forming composition of this embodiment can also be used in an embodiment in which multiple resist underlayer films are laminated. In this case, the position (which layer is laminated) of the resist underlayer film formed using the resist underlayer film forming composition of this embodiment is not particularly limited, and may be directly under the upper layer resist, may be the layer located closest to the substrate, or may be sandwiched between the resist underlayer films.

In forming a fine pattern, the resist film tends to be thin in order to prevent the pattern from collapsing. Dry etching for transferring a pattern to a film existing in an underlying layer by thinning the resist film must have a higher etching rate than the film in the upper layer in order to transfer the pattern. In this embodiment, an organic underlayer film is placed on a substrate, and the resist underlayer film (containing a silicon-based compound) of this embodiment is coated on the organic underlayer film, which is then coated with a resist film (organic resist film). The dry etching rate of the organic component film and the inorganic component film is significantly different depending on the etching gas selected, and the dry etching rate of the organic component film is high with an oxygen-based gas, and the dry etching rate of the inorganic component film is high with a halogen-containing gas.
For example, using a resist underlayer film to which a pattern has been transferred, the organic underlayer film underneath can be dry etched with an oxygen-based gas to transfer the pattern to the organic underlayer film, and then the organic underlayer film to which the pattern has been transferred can be used to process the substrate using a halogen-containing gas.

In addition, the resist underlayer film formed by the resist underlayer film forming composition of this embodiment contains a tellurium-containing compound or a resin containing a structural unit derived from said compound, which has excellent absorption ability for actinic radiation, and a silicon-containing compound (e.g., a hydrolyzable organosilane, its hydrolysate, or its hydrolyzed condensate), thereby improving the sensitivity of the upper layer resist, preventing intermixing with the upper layer resist, and resulting in a rectangular pattern shape for the resist underlayer film formed film after exposure and development. This makes it possible to process substrates with fine patterns.

In addition, the resist underlayer film formed by the resist underlayer film forming composition of this embodiment has high heat resistance, so it can be used even under high temperature baking conditions. Furthermore, since it has a relatively low molecular weight and low viscosity, it is easy to uniformly fill every corner even in a substrate having a step (especially a fine space or hole pattern, etc.), and as a result, the planarization property and filling property tend to be relatively advantageously improved.

The resist underlayer film-forming composition may further contain a solvent, an acid, an acid crosslinking agent, and the like, in addition to the compound or resin according to this embodiment and the silicon-containing compound. In addition, as optional components, an organic polymer compound, an acid generator, a surfactant, and other components such as water, alcohol, and a curing catalyst may be contained. From the viewpoint of coatability and quality stability, the content of the compound and resin according to this embodiment in the resist underlayer film-forming composition is preferably 0.1 to 70% by mass, more preferably 0.5 to 50% by mass, and particularly preferably 3.0 to 40% by mass.

-solvent-
As the solvent used in this embodiment, any known solvent can be used as appropriate as long as it can dissolve at least the compound represented by the above formula (X) or a resin containing a structural unit derived from the compound. For example, the solvent that can be contained in the composition for forming a resist underlayer film disclosed in International Publication No. 2017/188450 can be mentioned.

The content of the solvent is not particularly limited, but from the viewpoints of solubility and film formation, it is preferably 100 to 10,000 parts by mass, more preferably 200 to 8,000 parts by mass, and even more preferably 200 to 5,000 parts by mass, per 100 parts by mass of the total solids content of the composition for forming the resist underlayer film.

-acid-
The composition for forming a resist underlayer film may contain an acid from the viewpoint of promoting curing. Examples of the acid include hydrofluoric acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, perchloric acid, phosphoric acid, methanesulfonic acid, benzenesulfonic acid, and toluenesulfone.

The content of the acid is not particularly limited, but from the viewpoint of solubility and shape stability of the coating film, it is preferably 0.001 to 20 parts by mass, more preferably 0.005 to 10 parts by mass, and even more preferably 0.01 to 5 parts by mass, relative to 100 parts by mass of the total solid content of the composition for forming a resist underlayer film.

- Acid crosslinking agent -
The resist underlayer film forming composition may contain one or more acid crosslinkers when used as a negative resist material or as an additive for increasing the strength of a pattern in a positive resist material. The acid crosslinker is a compound that can intramolecularly or intermolecularly crosslink a resin containing a compound represented by the formula (X) or a structural unit derived from the compound in the presence of the above-mentioned acid. Such an acid crosslinker is not particularly limited, but may be, for example, a compound having one or more groups (hereinafter referred to as "crosslinkable groups") that can crosslink a compound represented by the formula (X) or a resin containing a structural unit derived from the compound. For example, an acid crosslinker that can be contained in a resist underlayer film forming composition disclosed in International Publication No. 2017/188450 may be mentioned. In addition, for example, those described in International Publication No. WO2013/024779 may also be mentioned as specific examples of the acid crosslinker.

The content of the acid crosslinker is not particularly limited, but from the viewpoint of solubility and shape stability of the coating film, it is preferably 0.01 to 30 parts by mass, more preferably 0.05 to 20 parts by mass, and even more preferably 0.1 to 10 parts by mass, relative to 100 parts by mass of the total solid content of the composition for forming a resist underlayer film.

-Silicon-containing compounds-
The resist underlayer film forming composition contains a silicon-containing compound together with the compound or resin according to this embodiment. The silicon-containing compound may be either an organic silicon-containing compound or an inorganic silicon-containing compound, but is preferably an organic silicon-containing compound. Examples of the inorganic silicon-containing compound include polysilazane compounds made of silicon oxide, silicon nitride, and silicon oxynitride, which can be formed into a film by a coating method at low temperature. Examples of the organic silicon-containing compound include polysilsesquioxane-based compounds, hydrolyzable organosilanes, their hydrolysates, and their hydrolyzed condensates. Specific examples of the polysilsesquioxane-based materials include, but are not limited to, those described in JP-A-2007-226170 and JP-A-2007-226204. The hydrolyzable organosilane, its hydrolyzate, or its hydrolyzed condensate may include at least one hydrolyzable organosilane selected from the group consisting of the hydrolyzable organosilane of the following formula (D1) and the following formula (D2), their hydrolyzate, or their hydrolyzed condensate (hereinafter, these may be simply referred to as "at least one organosilicon compound selected from the group consisting of formula (D1) and formula (D2)"). When the resist underlayer film forming composition contains at least one organosilicon compound selected from the group consisting of formula (D1) and formula (D2), it is easy to control the Si-O bond by adjusting the curing conditions, it is advantageous in terms of cost, and it is suitable for introducing organic components. For this reason, a layer formed using the resist underlayer film forming composition containing at least one organosilicon compound selected from the group consisting of formula (D1) and formula (D2) is useful as an intermediate layer of a resist layer (a layer between an upper resist layer and an organic underlayer film provided on a substrate).

Formula (D1): (R ³ ) _a Si(R ⁴ ) _4-a
In formula (D1), ^R3 represents an alkyl group, an aryl group, an aralkyl group, a halogenated alkyl group, a halogenated aryl group, a halogenated aralkyl group, an alkenyl group, an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, "Organic radical" having an alkoxyaryl group, an acyloxyaryl group, an isocyanurate group, a hydroxy group, a cyclic amino group, or a cyano group; or a combination thereof, and bonded to the silicon atom by a Si-C bond. R ⁴ represents an alkoxy group, an acyloxy group, or a halogen group, and a represents an integer of 0 to 3.

Formula (D2): [(R ⁵ ) _c Si(R ⁶ ) _4-c ] ₂ Y _b
In formula (D2), R ⁵ represents an alkyl group, R ⁶ represents an alkoxy group, an acyloxy group, or a halogen group, Y represents an alkylene group or an arylene group, b represents an integer of 0 or 1, represents an integer of 0 or 1.)

In the composition for forming the resist underlayer film, the ratio of the tellurium-containing compound represented by formula (X) and the resin containing structural units derived from the compound to the silicon-containing compound (for example, at least one organosilicon compound selected from the group consisting of formulas (D1) and (D2)) can be used in a molar ratio range of 1:2 to 1:200. In order to obtain a good resist shape, for example, the molar ratio can be used in a range of 1:2 to 1:100. It is preferable to use at least one organosilicon compound selected from the group consisting of formulas (D1) and (D2) as a hydrolysis condensation product (polymer of polyorganosiloxane).

In the hydrolyzable organosilane represented by formula (D1), R ³ is an "organic group" having an alkyl group, an aryl group, an aralkyl group, a halogenated alkyl group, a halogenated aryl group, a halogenated aralkyl group, an alkenyl group, an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an alkoxyaryl group, an acyloxyaryl group, an isocyanurate group, a hydroxy group, a cyclic amino group, or a cyano group, or a combination thereof, and is bonded to a silicon atom via a Si-C bond; R ⁴ represents an alkoxy group, an acyloxy group, or a halogen group; and a represents an integer of 0 to 3.

In the hydrolyzable organosilane of formula (D2), ^R5 represents an alkyl group, ^R6 represents an alkoxy group, an acyloxy group, or a halogen group, Y represents an alkylene group or an arylene group, b represents an integer of 0 or 1, and c represents an integer of 0 or 1.

Examples of hydrolyzable organosilanes represented by formula (D1) and formula (D2) include the hydrolyzable organosilanes that can be included in the composition for forming a resist underlayer film disclosed in International Publication No. 2017/188450.

In this embodiment, a film may be formed as a mixture of the tellurium compound or a resin containing a structural unit derived from the compound and the hydrolyzable organosilane, etc., without reacting them. Alternatively, a tellurium-containing silicon compound or resin may be synthesized by hydrolysis and condensation of the tellurium-containing compound in the composition for forming a resist underlayer film or the resin containing a structural unit derived from the compound and the above-mentioned hydrolyzable organosilane, etc., using one or more compounds selected from inorganic acids, aliphatic sulfonic acids, and aromatic sulfonic acids as an acid catalyst.

Examples of the acid catalyst used at this time include hydrofluoric acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, perchloric acid, phosphoric acid, methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, etc. The amount of the catalyst used is preferably 10 ⁻⁶ to 10 mol, more preferably 10 ⁻⁵ to 5 mol, and even more preferably 10 −4 to 1 mol per mol of monomer (the total amount of the tellurium-containing compound and the resin containing a structural unit derived from said compound, and the ^hydrolyzable organosilane, etc.).

When obtaining tellurium-containing silicon compounds or resins from these monomers by hydrolysis and condensation, the amount of water added is preferably 0.01 to 100 moles per mole of hydrolyzable substituent bonded to the monomer (compounds containing tellurium, resins containing structural units derived from said compounds, hydrolyzable organosilanes, etc.), more preferably 0.05 to 50 moles, and even more preferably 0.1 to 30 moles. Addition of 100 moles or less is economical because the equipment used for the reaction does not become excessively large.

As an operating method for synthesizing tellurium-containing silicon compounds or resins, for example, a monomer is added to an aqueous catalyst solution to initiate a hydrolysis condensation reaction. At this time, an organic solvent may be added to the aqueous catalyst solution, or the monomer may be diluted with an organic solvent, or both may be performed. The reaction temperature is preferably 0 to 100°C, more preferably 40 to 100°C. A method in which the temperature is kept at 5 to 80°C during the dropwise addition of the monomer, and then the mixture is aged at 40 to 100°C is preferred.

Organic solvents that can be added to the aqueous catalyst solution or used to dilute the monomer include, for example, the organic solvents disclosed in WO 2017/188450.

The amount of organic solvent used is preferably 0 to 1,000 ml, particularly preferably 0 to 500 ml, per mole of monomer (total amount of tellurium-containing compound, resin containing structural units derived from said compound, and hydrolyzable organosilane, etc.). If the amount of organic solvent used is 1,000 ml or less, it is economical because the reaction vessel will not become excessively large.

If necessary, the catalyst is neutralized, and the alcohol produced in the hydrolysis and condensation reaction is removed under reduced pressure to obtain an aqueous reaction mixture. At this time, the amount of alkaline substance that can be used for neutralization is preferably 0.1 to 2 equivalents relative to the acid used in the catalyst. This alkaline substance can be any substance that is alkaline in water.

Next, it is preferable to remove by-products such as alcohol generated by the hydrolysis condensation reaction from the reaction mixture. The temperature at which the reaction mixture is heated depends on the type of organic solvent added and the alcohol generated by the reaction, but is preferably 0 to 100°C, more preferably 10 to 90°C, and even more preferably 15 to 80°C. The degree of reduced pressure at this time varies depending on the type of organic solvent and alcohol to be removed, the exhaust device, the condenser, and the heating temperature, but is preferably atmospheric pressure or less, more preferably 80 kPa or less in absolute pressure, and even more preferably 50 kPa or less in absolute pressure. It is difficult to know the exact amount of alcohol removed at this time, but it is desirable to remove approximately 80 mass% or more of the generated alcohol.

Next, the acid catalyst used in the hydrolysis and condensation may be removed from the reaction mixture. An example of a method for removing the acid catalyst is a method in which water and a tellurium-containing silicon compound or resin are mixed, and the tellurium-containing silicon compound or resin is extracted with an organic solvent. The organic solvent used in this case is preferably one that can dissolve the tellurium-containing silicon compound or resin and separates into two layers when mixed with water. For example, the organic solvents disclosed in International Publication No. 2017/188450 can be mentioned.

Furthermore, when removing the acid catalyst used in the hydrolysis and condensation from the reaction mixture, it is also possible to use a mixture of a water-soluble organic solvent and a poorly water-soluble organic solvent. For example, the mixture disclosed in WO 2017/188450 can be used.

The mixing ratio of the water-soluble organic solvent to the poorly water-soluble organic solvent may be appropriately selected, but it is preferable that the water-soluble organic solvent be 0.1 to 1,000 parts by mass, more preferably 1 to 500 parts by mass, and even more preferably 2 to 100 parts by mass, per 100 parts by mass of the poorly water-soluble organic solvent.

In both cases, a tellurium-containing silicon compound or resin containing residual acid catalyst and a tellurium-containing silicon compound or resin from which the acid catalyst has been removed, can be obtained by adding a final solvent and performing solvent exchange under reduced pressure. The temperature for the solvent exchange at this time depends on the type of reaction solvent and extraction solvent to be removed, but is preferably 0 to 100°C, more preferably 10 to 90°C, and even more preferably 15 to 80°C. The degree of reduced pressure at this time varies depending on the type of extraction solvent to be removed, the exhaust device, the condenser, and the heating temperature, but is preferably atmospheric pressure or less, more preferably 80 kPa or less in absolute pressure, and even more preferably 50 kPa or less in absolute pressure.

-Other optional ingredients-
The composition for forming a resist underlayer film may contain, in addition to the above-mentioned components, an organic polymer compound, a crosslinking agent, a photoacid generator, a surfactant, and the like, if necessary.

By using an organic polymer compound, the dry etching rate (amount of film thickness reduction per unit time), attenuation coefficient, refractive index, etc. of the resist underlayer film formed from the composition for forming a resist underlayer film can be adjusted. There are no particular limitations on the organic polymer compound, and various organic polymers can be used. Condensation polymerization polymers and addition polymerization polymers, etc. can be used. For example, the organic polymer compounds disclosed in International Publication No. 2017/188450 can be used.

By using a crosslinking agent, the dry etching rate (amount of film thickness reduction per unit time) of the resist underlayer film formed from the resist underlayer film forming composition can be adjusted. There is no particular limitation on the crosslinking agent, and various crosslinking agents can be used. Specific examples of crosslinking agents that can be used in this embodiment include, for example, melamine compounds, guanamine compounds, glycoluril compounds, urea compounds, epoxy compounds, thioepoxy compounds, isocyanate compounds, azide compounds, and compounds containing double bonds such as alkenyl ether groups, and having at least one group selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group as a substituent (crosslinkable group), but are not particularly limited thereto. For example, crosslinking agents disclosed in International Publication No. 2017/188450 can be mentioned.

In the composition for forming a resist underlayer film, the content of the crosslinking agent is not particularly limited, but is preferably 1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the resin containing a tellurium-containing compound and a structural unit derived from the compound. By setting the content within the above-mentioned preferred range, the occurrence of the mixing phenomenon with the resist layer tends to be suppressed, the anti-reflection effect tends to be enhanced, and the film formability after crosslinking tends to be improved.

The resist underlayer film forming composition may contain an acid generator. Known acid generators include those that generate acid by thermal decomposition and those that generate acid by light irradiation, and any of these may be used. As the acid generator, for example, those described in International Publication WO2013/024779 may be used.

When an acid generator is used, the proportion thereof is 0.01 parts by mass to 5 parts by mass, or 0.1 parts by mass to 3 parts by mass, or 0.5 parts by mass to 1 part by mass per 100 parts by mass of the resin containing a tellurium-containing compound and a structural unit derived from the compound.

The surfactant is effective in suppressing the occurrence of surface defects and the like when the composition for forming a resist underlayer film is applied to a substrate. Examples of the surfactant contained in the composition for forming a resist underlayer film include the surfactants disclosed in International Publication No. 2017/188450. When a surfactant is used, the proportion thereof is, for example, 0.0001 to 5 parts by mass, or 0.001 to 1 part by mass, or 0.01 to 0.5 parts by mass, relative to 100 parts by mass of a resin containing a tellurium-containing compound and a structural unit derived from the compound.

<Underlayer film for lithography and pattern formation method>
The underlayer film for lithography according to the first embodiment of the present invention can be formed by using the composition for forming a resist underlayer film according to the first embodiment of the present invention. The underlayer film for lithography according to this embodiment can be suitably used as an underlayer (resist underlayer film) of a photoresist (upper layer) used in a multilayer resist method.

In this embodiment, for example, a resist underlayer film is formed using a composition for forming a resist underlayer film, at least one photoresist layer is formed on the resist underlayer film, and then a predetermined area of the photoresist layer is irradiated with radiation and developed to form a pattern.

In addition, one aspect of the pattern formation method according to the first embodiment of the present invention using the resist underlayer film forming composition according to the first embodiment of the present invention prepared as described above includes forming an organic underlayer film on a substrate using a coating type organic underlayer film material, forming a resist underlayer film on the organic underlayer film using the resist underlayer film forming composition of the first embodiment of the present invention, forming an upper-layer resist film on the resist underlayer film using an upper-layer resist film composition, forming an upper-layer resist pattern on the upper-layer resist film, transferring a pattern to the resist underlayer film by etching using the upper-layer resist pattern as a mask, transferring a pattern to the organic underlayer film by etching using the resist underlayer film to which the pattern has been transferred as a mask, and further transferring a pattern to the substrate (workpiece) by etching using the organic underlayer film to which the pattern has been transferred as a mask.

Another aspect of the pattern formation method according to the first embodiment of the present invention is a pattern formation method in which an organic hard mask mainly composed of carbon is formed on a substrate by a CVD method, a resist underlayer film is formed on the organic hard mask using the resist underlayer film forming composition of the first embodiment of the present invention, an upper layer resist film is formed on the resist underlayer film using an upper layer resist film composition, an upper layer resist pattern is formed on the upper layer resist film, the pattern is transferred to the resist underlayer film by etching using the upper layer resist pattern as a mask, the pattern is transferred to the organic hard mask by etching using the resist underlayer film to which the pattern has been transferred as a mask, and the pattern is further transferred to the substrate (workpiece) by etching using the organic hard mask to which the pattern has been transferred as a mask.

The base material may be, for example, a semiconductor substrate. The semiconductor substrate may generally be a silicon substrate, but is not particularly limited thereto, and may be made of a material different from the layer to be processed, such as Si, amorphous silicon (α-Si), p-Si, SiO ₂ , SiN, SiON, W, TiN, or Al.

The metal constituting the base material (workpiece; including the semiconductor substrate) can be any of silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, and molybdenum, or an alloy thereof.

Also, a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, or a metal oxide nitride film formed on a semiconductor substrate as a layer to be processed (a portion to be processed) can be used. Examples of such a metal-containing layer to be processed include Si, SiO ₂ , SiN, SiON, SiOC, p-Si, α-Si, TiN, WSi, BPSG, SOG, Cr, CrO, CrON, MoSi, W, W-Si, Al, Cu, Al-Si, and various low dielectric films and their etching stopper films, and can be formed to a thickness of usually 50 to 10,000 nm, particularly 100 to 5,000 nm.

In the pattern formation method of the present embodiment, an organic underlayer film or an organic hard mask can be formed on a substrate. Among them, the organic underlayer film can be formed from a coating-type organic underlayer film material using a spin coating method or the like, and the organic hard mask can be formed from an organic hard mask material mainly composed of carbon using a CVD method. The types of such organic underlayer film and organic hard mask are not particularly limited, but when the upper resist film is patterned by exposure, it is preferable that the organic underlayer film and organic hard mask exhibit sufficient anti-reflective film function. By forming such an organic underlayer film or organic hard mask, the pattern formed by the upper resist film can be transferred onto the substrate (workpiece) without causing a size conversion difference. Note that a hard mask "mainly composed of carbon" means a hard mask in which 50% or more by mass of the solid content is composed of a carbon-based material such as amorphous hydrogenated carbon, also called amorphous carbon and denoted as a-C:H. The a-C:H film can be deposited by various techniques, but plasma enhanced chemical vapor deposition (PECVD) is widely used due to its cost-effectiveness and film quality adjustability. As an example of the hard mask, for example, the one described in JP-T-2013-526783 can be referred to.

The resist underlayer film using the resist underlayer film forming composition of this embodiment used in the pattern forming method of this embodiment can be formed on a workpiece provided with an organic underlayer film or the like by spin coating or the like from the resist underlayer film forming composition. When forming the resist underlayer film by spin coating, it is desirable to evaporate the solvent after spin coating and bake to promote the crosslinking reaction in order to prevent mixing with the upper resist film. The bake temperature is preferably within the range of 50 to 500°C. At this time, although it depends on the structure of the device to be manufactured, a bake temperature of 400°C or less is particularly preferable in order to reduce thermal damage to the device. A bake time within the range of 10 to 300 seconds is preferably used.

In addition, in the pattern formation method of this embodiment, as a method for forming a pattern on the upper resist film, any of the following methods can be suitably used: lithography using light having a wavelength of 300 nm or less or EUV light; electron beam direct writing; and induced self-organization. By using such a method, a fine pattern can be formed on the upper resist film.

The upper layer resist film composition can be appropriately selected according to the method for forming a pattern on the above-mentioned upper layer resist film. For example, when performing lithography using light of 300 nm or less or EUV light, a chemically amplified photoresist film material can be used as the upper layer resist film composition. Examples of such photoresist film materials include those that form a positive pattern by dissolving the exposed parts using an alkaline developer after forming a photoresist film and exposing it, and those that form a negative pattern by dissolving the unexposed parts using a developer made of an organic solvent.

The resist underlayer film formed from the resist underlayer film forming composition of this embodiment may absorb light depending on the wavelength of the light used in the lithography process. In such a case, it can function as an anti-reflective film that has the effect of preventing light from being reflected from the substrate.

In addition to its function as a hard mask, the underlayer film of an EUV resist can also be used for the following purposes. The tellurium-containing composition for forming a resist underlayer film can be used as an underlayer anti-reflective film of an EUV resist that can prevent the reflection of undesirable exposure light, such as the above-mentioned UV and DUV (ArF light, KrF light), from the substrate or interface during EUV exposure (wavelength 13.5 nm) without intermixing with the EUV resist. Reflection can be efficiently prevented in the underlayer of the EUV resist. In addition, since the composition for forming the underlayer film has excellent EUV absorption ability, it is possible to exert a sensitizing effect on the upper layer resist composition, contributing to improved sensitivity. When used as an EUV resist underlayer film, the process can be carried out in the same manner as for the underlayer film for photoresist.

Second Embodiment
<Composition for forming resist underlayer film>
The composition for forming a resist underlayer film according to the second embodiment of the present invention is a composition for forming a resist underlayer film containing the compound or resin according to this embodiment. The composition for forming a resist underlayer film according to this embodiment can reduce defects in the film (form a thin film), has good storage stability, has high sensitivity, has a high refractive index and transparency in a specific wavelength region, and can provide a good resist pattern shape. The composition for forming a resist underlayer film according to this embodiment can be free of a silicon-containing compound.

The resist underlayer film forming composition of this embodiment is applicable to a wet process, and can realize a resist underlayer film forming composition useful for forming a photoresist underlayer film having excellent heat resistance, step filling properties, and flatness. This resist underlayer film forming composition uses a compound having a specific structure with a relatively high carbon concentration, a relatively low oxygen concentration, and high solvent solubility, and therefore can form an underlayer film that suppresses film deterioration during baking and has excellent etching resistance against fluorine gas-based plasma etching and the like. Furthermore, since it has excellent adhesion to the resist layer, an excellent resist pattern can be formed. The resist underlayer film forming composition of this embodiment is particularly excellent in heat resistance, step filling properties, and flatness, and can be used, for example, as a composition for forming a resist underlayer film provided on the lowest layer of a plurality of resist layers. However, the resist underlayer film formed using the resist underlayer film forming composition of this embodiment may further include another resist underlayer between the substrate.

The composition for forming a resist underlayer film according to this embodiment may further contain a solvent, an acid generator, an acid crosslinking agent, etc., in addition to the compound according to this embodiment. In addition, as optional components, a basic compound, water, an alcohol, a curing catalyst, etc. may be contained. From the viewpoint of coatability and quality stability, the content of the compound according to this embodiment in the composition for forming a resist underlayer film is preferably 0.1 to 70% by mass, more preferably 0.5 to 50% by mass, and particularly preferably 3.0 to 40% by mass.

-solvent-
As the solvent used in this embodiment, any known solvent can be used as appropriate as long as it dissolves at least the compound represented by the above formula (X) or a resin containing a structural unit derived from the compound. For example, the solvents disclosed in International Publication No. 2017/188451 can be used.

The content of the solvent is not particularly limited, but from the viewpoints of solubility and film formation, it is preferably 100 to 10,000 parts by mass, more preferably 200 to 5,000 parts by mass, and even more preferably 200 to 1,000 parts by mass, per 100 parts by mass of the total solids content of the composition for forming the resist underlayer film.

- Acid crosslinking agent -
As described above, the resist underlayer film forming composition of the present embodiment may contain an acid crosslinking agent as necessary from the viewpoint of suppressing intermixing, etc. Examples of acid crosslinking agents that can be used in the present embodiment include, for example, melamine compounds, epoxy compounds, guanamine compounds, glycoluril compounds, urea compounds, thioepoxy compounds, isocyanate compounds, azide compounds, and compounds containing double bonds such as alkenyl ether groups, and having at least one group selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group as a substituent (crosslinkable group), but are not particularly limited thereto. These acid crosslinking agents can be used alone or in combination of two or more. These may also be used as additives. Compounds containing a hydroxyl group can also be used as crosslinking agents. Specific examples of the acid crosslinking agents include those described in International Publication No. WO 2013/024779.

In the composition for forming a resist underlayer film of this embodiment, the content of the acid crosslinker is not particularly limited, but is preferably 5 to 50 parts by mass, and more preferably 10 to 40 parts by mass, relative to 100 parts by mass of the total solid content of the composition for forming a resist underlayer film. By setting the content within the above-mentioned preferred range, the occurrence of the mixing phenomenon with the resist layer tends to be suppressed, the anti-reflection effect tends to be enhanced, and the film formability after crosslinking tends to be improved.

- Acid generator -
The resist underlayer film forming composition of the present embodiment may contain an acid generator as necessary from the viewpoint of further promoting the crosslinking reaction by heat. As the acid generator, there are known ones that generate acid by thermal decomposition, ones that generate acid by light irradiation, etc., and any of them can be used. As the acid generator, for example, those described in International Publication WO2013/024779 can be used.

In the composition for forming a resist underlayer film of this embodiment, the content of the acid generator is not particularly limited, but is preferably 0.1 to 50 parts by mass, and more preferably 0.5 to 40 parts by mass, relative to 100 parts by mass of the total solid content of the composition for forming a resist underlayer film. By setting the content within the above-mentioned preferred range, the amount of acid generated tends to increase, enhancing the crosslinking reaction, and also tends to suppress the occurrence of a mixing phenomenon with the resist layer.

- Basic compounds -
Furthermore, the composition for forming a resist underlayer film of the present embodiment may contain a basic compound from the viewpoint of improving storage stability, etc.

The basic compound acts as a quencher for the acid to prevent the acid generated in small amounts from the acid generator from proceeding with the crosslinking reaction. Examples of such basic compounds include, but are not limited to, primary, secondary, or tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amide derivatives, and imide derivatives. Specific examples of basic compounds include those described in International Publication WO 2013/024779.

In the composition for forming a resist underlayer film of this embodiment, the content of the basic compound is not particularly limited, but is preferably 0.001 to 2 parts by mass, and more preferably 0.01 to 1 part by mass, relative to 100 parts by mass of the total solid content of the composition for forming a resist underlayer film. By setting the content within the above-mentioned preferred range, storage stability tends to be improved without excessively impairing the crosslinking reaction.

In addition, the resist underlayer film forming composition of this embodiment may contain other resins or compounds for the purpose of imparting thermosetting properties or controlling absorbance. Examples of such other resins or compounds include naphthol resins, xylene resins, naphthol-modified resins, phenol-modified resins of naphthalene resins, polyhydroxystyrene, dicyclopentadiene resins, (meth)acrylates, dimethacrylates, trimethacrylates, tetramethacrylates, vinylnaphthalenes, polyacenaphthylenes, and other naphthalene rings, phenanthrenequinones, fluorenes, and other biphenyl rings, thiophenes, indenes, and other heterocyclic rings having heteroatoms, and resins not containing aromatic rings; rosin-based resins, cyclodextrins, adamantane (poly)ols, tricyclodecane (poly)ols, and derivatives thereof, and other resins or compounds containing alicyclic structures, but are not particularly limited thereto. In addition, the resist underlayer film forming composition of this embodiment may contain known additives. Examples of the known additives include, but are not limited to, ultraviolet absorbers, surfactants, colorants, and nonionic surfactants.

<Lithography Resist Underlayer Film and Pattern Forming Method>
The resist underlayer film for lithography according to the second embodiment of the present invention is formed by using the composition for forming a resist underlayer film according to the second embodiment of the present invention. The pattern formed in this embodiment can be used as, for example, a resist pattern or a circuit pattern.

The pattern formation method according to the second embodiment of the present invention includes a step (A-1 step) of forming a resist underlayer film on a substrate using the resist underlayer film forming composition of the second embodiment of the present invention, a step (A-2 step) of forming at least one photoresist layer on the resist underlayer film, and a step (A-3 step) of irradiating a predetermined region of the photoresist layer with radiation and developing the photoresist layer after forming the at least one photoresist layer in the A-2 step. Note that the "photoresist layer" refers to the outermost layer of the resist layer, i.e., the layer provided on the outermost side of the resist layer (the side opposite to the substrate).

Further, another pattern formation method of the second embodiment of the present invention includes a step (B-1 step) of forming a resist underlayer film on a substrate using the resist underlayer film forming composition of the second embodiment of the present invention, a step (B-2 step) of forming a resist intermediate layer film on the underlayer film using a resist intermediate layer film material (e.g., a silicon-containing resist layer), a step (B-3 step) of forming at least one photoresist layer on the resist intermediate layer film, a step (B-4 step) of irradiating a predetermined region of the photoresist layer with radiation and developing the photoresist layer to form a resist pattern after the at least one photoresist layer is formed in the B-3 step, and a step (B-5 step) of etching the resist intermediate layer film using the resist pattern as a mask, etching the underlayer film using the obtained intermediate layer film pattern as an etching mask, and etching the substrate using the obtained underlayer film pattern as an etching mask to form a pattern on the substrate.

The resist underlayer film for lithography of this embodiment can be formed by any known method, as long as it is formed from the composition for forming a resist underlayer film of this embodiment. For example, the composition for forming a resist underlayer film of this embodiment can be applied to a substrate by a known coating method or printing method such as spin coating or screen printing, and then the organic solvent can be removed by volatilizing the organic solvent to form a resist underlayer film.

When forming the resist underlayer film, it is preferable to perform a bake treatment in order to suppress the occurrence of a mixing phenomenon with the upper resist layer (e.g., a photoresist layer or a resist intermediate layer film) and to promote a crosslinking reaction. In this case, the bake temperature is not particularly limited, but is preferably in the range of 80 to 450°C, and more preferably 200 to 400°C. In addition, the bake time is also not particularly limited, but is preferably in the range of 10 seconds to 300 seconds. The thickness of the resist underlayer film can be appropriately selected according to the required performance, and is not particularly limited, but is usually preferably about 30 to 20,000 nm, and more preferably 50 to 15,000 nm.

After preparing a resist underlayer film on a substrate, a resist intermediate layer film can be provided between the photoresist layer and the resist underlayer film. For example, in the case of a two-layer process, a silicon-containing resist layer or a monolayer resist made of a normal hydrocarbon can be provided as a resist intermediate layer film on the resist underlayer film. Also, for example, in the case of a three-layer process, it is preferable to prepare a silicon-containing intermediate layer between the resist intermediate layer film and the photoresist layer, and further a silicon-free monolayer resist layer on top of that. Known photoresist materials can be used to form the photoresist layer, the resist intermediate layer film, and the resist layer provided between these layers.

For example, from the viewpoint of oxygen gas etching resistance, a silicon-containing resist material for a two-layer process is preferably a positive photoresist material that uses a silicon atom-containing polymer such as a polysilsesquioxane derivative or a vinylsilane derivative as a base polymer, and further contains an organic solvent, an acid generator, and, if necessary, a basic compound. Here, the silicon atom-containing polymer may be a known polymer used in this type of resist material.

For example, a polysilsesquioxane-based intermediate layer is preferably used as a silicon-containing intermediate layer for a three-layer process. By making the resist intermediate layer effective as an anti-reflective film, reflection tends to be effectively suppressed. For example, in a 193 nm exposure process, if a material containing many aromatic groups and having high substrate etching resistance is used as the resist underlayer film, the k value tends to be high and the substrate reflection tends to be high, but by suppressing reflection with the resist intermediate layer film, the substrate reflection can be reduced to 0.5% or less. As an intermediate layer having such an anti-reflective effect, but not limited to the following, for 193 nm exposure, a polysilsesquioxane that is crosslinked by acid or heat and has a light-absorbing group having a phenyl group or a silicon-silicon bond introduced therein is preferably used.

A resist intermediate layer film formed by the Chemical Vapor Deposition (CVD) method can also be used. As an intermediate layer that is highly effective as an anti-reflective film produced by the CVD method, for example, a SiON film is known, but is not limited to the following. In general, the formation of a resist intermediate layer film by a wet process such as a spin coating method or screen printing has a simpler and more cost-effective advantage than the CVD method. The upper layer resist in the three-layer process may be either positive or negative, and the same resist as the commonly used single-layer resist can be used.

Furthermore, the resist underlayer film of this embodiment can be used as an anti-reflective film for a normal single-layer resist or as an underlayer material for suppressing pattern collapse. The resist underlayer film of this embodiment has excellent etching resistance for underlayer processing, so it can also be expected to function as a hard mask for underlayer processing.

When forming a resist layer using the above-mentioned known photoresist material, wet processes such as spin coating and screen printing are preferably used, as in the case of forming the resist underlayer film. After applying the resist material by spin coating or the like, pre-baking is usually performed, and this pre-baking is preferably performed at a baking temperature of 80 to 180°C and for a baking time of 10 to 300 seconds. Thereafter, exposure is performed according to a conventional method, followed by post-exposure baking (PEB) and development to obtain a resist pattern. The thickness of each resist film is not particularly limited, but generally, it is preferably 30 nm to 500 nm, and more preferably 50 nm to 400 nm.

The exposure light may be appropriately selected depending on the photoresist material used. Generally, high-energy rays with a wavelength of 300 nm or less, specifically, excimer lasers with wavelengths of 248 nm, 193 nm, and 157 nm, soft X-rays with wavelengths of 3 to 20 nm, electron beams, X-rays, etc., are used.

The resist pattern formed by the above-mentioned method is one in which pattern collapse is suppressed by the resist underlayer film of this embodiment. Therefore, by using the resist underlayer film of this embodiment, a finer pattern can be obtained, and the exposure dose required to obtain the resist pattern can be reduced.

Next, etching is performed using the obtained resist pattern as a mask. Gas etching is preferably used as etching of the resist underlayer film in the two-layer process. As the gas etching, etching using oxygen gas is suitable. In addition to oxygen gas, it is also possible to add inert gases such as He and Ar, or CO, CO ₂ , NH ₃ , SO ₂ , N ₂ , NO ₂ , and H ₂ gases. Gas etching can also be performed using only CO, CO ₂ , NH ₃ , N ₂ , NO ₂ , and H ₂ gases without using oxygen gas. In particular, the latter gas is preferably used for sidewall protection to prevent undercut of the pattern sidewall.

On the other hand, gas etching is also preferably used for etching the middle layer (the layer located between the photoresist layer and the resist underlayer film) in the three-layer process. The gas etching can be the same as that described in the two-layer process. In particular, the processing of the middle layer in the three-layer process is preferably performed using a fluorocarbon-based gas with the resist pattern as a mask. After that, the resist underlayer film can be processed by, for example, performing oxygen gas etching with the middle layer pattern as a mask as described above.

Here, when forming an inorganic hard mask intermediate layer film as the intermediate layer, a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiON film) is formed by a CVD method, an ALD method, or the like. The method for forming the nitride film is not limited to the following, but for example, the methods described in JP-A-2002-334869 and WO2004/066377 can be used. A photoresist film can be formed directly on such an intermediate layer film, but an organic anti-reflective coating (BARC) may also be formed on the intermediate layer film by spin coating, and a photoresist film may be formed on top of that.

A polysilsesquioxane-based intermediate layer is also preferably used as the intermediate layer. By making the resist intermediate film effective as an anti-reflective film, reflection tends to be effectively suppressed. Specific materials for the polysilsesquioxane-based intermediate layer are not limited to the following, but for example, those described in JP-A-2007-226170 and JP-A-2007-226204 can be used.

The etching of the substrate can also be performed by a conventional method, for example, if the substrate is SiO ₂ or SiN, etching can be performed mainly with a fluorocarbon-based gas, and if the substrate is p-Si, Al, or W, etching can be performed mainly with a chlorine-based or bromine-based gas. When etching the substrate with a fluorocarbon-based gas, the silicon-containing resist of the two-layer resist process and the silicon-containing intermediate layer of the three-layer process are stripped at the same time as the substrate is processed. On the other hand, when the substrate is etched with a chlorine-based or bromine-based gas, the silicon-containing resist layer or the silicon-containing intermediate layer is stripped separately, and generally, dry etching stripping with a fluorocarbon-based gas is performed after the substrate is processed.

The resist underlayer film of the present embodiment has excellent etching resistance to these substrates. The substrate may be appropriately selected from known substrates and may be any of, but is not limited to, Si, α-Si, p-Si, SiO ₂ , SiN, SiON, W, TiN, Al, and the like. The substrate may be a laminate having a film to be processed (substrate to be processed) on a base material (support). Examples of such a film to be processed include various low-k films such as Si, SiO ₂ , SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, and stopper films thereof, and films made of a material different from that of the base material (support) are usually used. The thickness of the substrate or film to be processed is not particularly limited, but is usually preferably about 50 nm to 10,000 nm, and more preferably 75 nm to 5,000 nm.

The resist underlayer film of this embodiment has excellent flatness and embedding properties in a substrate having a step. A known method for evaluating the flatness and embedding properties can be appropriately selected and used, and is not particularly limited. For example, a solution of each compound adjusted to a predetermined concentration is applied by spin coating onto a silicon substrate having a step, and the solution is dried at 110°C for 90 seconds to remove the solvent, forming a tellurium-containing underlayer film to a predetermined thickness. After baking for a predetermined time at a temperature of about 240 to 300°C, the difference in the thickness of the underlayer film between the line and space region and the open region without a pattern (ΔT) is measured by an ellipsometer, whereby the flatness and embedding properties in a substrate having a step can be evaluated.

[Optical article-forming composition and cured product thereof]
The optical component forming composition according to this embodiment is an optical component forming composition containing the compound or resin according to this embodiment. The optical component forming composition is usefully used for optical materials. The optical component forming composition according to this embodiment contains a compound containing tellurium or a resin containing a structural unit derived from the compound, so that a high refractive index and high transparency can be expected, and further, storage stability, structure forming ability (film forming ability), and heat resistance can be expected.
From the viewpoint of miniaturization of optical components and improvement of light collection efficiency, the refractive index of the optical article is preferably 1.65 or more, more preferably 1.70 or more, and even more preferably 1.75 or more. From the viewpoint of improvement of light collection efficiency, the transparency of the optical article is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more.
The method for measuring the refractive index is not particularly limited, and a known method is used. For example, spectroscopic ellipsometry, minimum deviation method, critical angle method (Abbe method, Pulfrich method), V-block method, prism coupler method, and immersion method (Becke line method) are included. The method for measuring the transparency is not particularly limited, and a known method is used. For example, a spectrophotometer and spectroscopic ellipsometry are included.

Furthermore, the cured product of this embodiment obtained by curing the optical component-forming composition can be a three-dimensional crosslinked product, and coloring is suppressed by a wide range of heat treatments from low to high temperatures, and a high refractive index and high transparency can be expected.

The optical component forming composition of this embodiment may further contain a solvent in addition to the compound represented by formula (X) or a resin containing a structural unit derived from the compound. The solvent may be the same as the solvent used in the lithography material composition of this embodiment described above.

In the optical component-forming composition of this embodiment, the relationship between the amount of solid components and the amount of solvent is not particularly limited, but is preferably 1 to 80% by mass of solid components and 20 to 99% by mass of solvent, more preferably 1 to 50% by mass of solid components and 50 to 99% by mass of solvent, even more preferably 2 to 40% by mass of solid components and 60 to 98% by mass of solvent, and particularly preferably 2 to 10% by mass of solid components and 90 to 98% by mass of solvent. The optical component-forming composition of this embodiment may not contain a solvent.

The optical component forming composition of this embodiment may contain at least one other solid component selected from the group consisting of an acid generator (C), an acid crosslinker (G), an acid diffusion control agent (E) and other components (F).

In the optical component forming composition of this embodiment, the content of the compound represented by formula (X) and the resin containing structural units derived from the compound is not particularly limited, but is preferably 50 to 99.4 mass % of the total mass of the solid components (the sum of the compound represented by formula (X) and the resin containing structural units derived from the compound, the acid generator (C), the acid crosslinker (G), the acid diffusion controller (E) and other components (F) and other optionally used solid components, the same applies below), more preferably 55 to 90 mass %, even more preferably 60 to 80 mass %, and particularly preferably 60 to 70 mass %.

(Acid Generator (C))
The optical part forming composition of the present embodiment preferably contains one or more acid generators (C) that generate acid directly or indirectly by heat. The acid generators (C) are not particularly limited and may be, for example, the same as the acid generators (C) that may be contained in the lithography material composition of the present embodiment described above.

In the optical component forming composition of this embodiment, the content of the acid generator (C) is preferably 0.001 to 49 mass % of the total mass of the solid components, more preferably 1 to 40 mass %, even more preferably 3 to 30 mass %, and particularly preferably 10 to 25 mass %. By using the acid generator (C) within the above content range, an even higher refractive index can be obtained.

(Acid Crosslinker (G))
When the optical component forming composition of the present embodiment is used as an additive for increasing the strength of the structure, it is preferable that the composition contains one or more acid crosslinkers (G). The acid crosslinker (G) is not particularly limited, and may be, for example, the same as the acid crosslinker (G) that may be contained in the lithography material composition of the present embodiment described above.

In the optical component forming composition of this embodiment, the content of the acid crosslinking agent (G) is preferably 0.5 to 49 mass % of the total mass of the solid components, more preferably 0.5 to 40 mass %, even more preferably 1 to 30 mass %, and particularly preferably 2 to 20 mass %. A content ratio of the acid crosslinking agent (G) of 0.5 mass % or more is preferable because it can improve the effect of suppressing the solubility of the optical component forming composition in organic solvents, while a content ratio of 49 mass % or less is preferable because it can suppress a decrease in the heat resistance of the optical component forming composition.

In addition, the content of at least one compound selected from the acid crosslinker (G1), the acid crosslinker (G2), and the acid crosslinker (G3) in the acid crosslinker (G) is not particularly limited, and can be in various ranges depending on factors such as the type of substrate used when forming the optical component forming composition.

(Acid Diffusion Controller (E))
The optical component forming composition of this embodiment may contain an acid diffusion control agent (E) that has the effect of controlling the diffusion of the acid generated from the acid generator in the optical component forming composition and preventing undesirable chemical reactions. By using such an acid diffusion control agent (E), the storage stability of the optical component forming composition is improved. In addition, the resolution is further improved, and the change in line width of the structure due to the variation in the delay time after heating can be suppressed, resulting in extremely excellent process stability. The acid diffusion control agent (E) is not particularly limited, and can be the same as the acid diffusion control agent (E) that can be contained in the lithography material composition of this embodiment described above.

The content of the acid diffusion control agent (E) is preferably 0.001 to 49% by mass of the total mass of the solid components, more preferably 0.01 to 10% by mass, even more preferably 0.01 to 5% by mass, and particularly preferably 0.01 to 3% by mass. When the content of the acid diffusion control agent (E) is within the above range, the deterioration of the resolution, pattern shape, dimensional fidelity, etc. can be further suppressed. Furthermore, even if the waiting time from electron beam irradiation to heating after radiation irradiation is long, the shape of the upper layer of the pattern does not deteriorate. In addition, when the content of the acid diffusion control agent (E) is 10% by mass or less, the deterioration of the sensitivity, developability of the unexposed part, etc. can be prevented. In addition, by using such an acid diffusion control agent, the storage stability of the optical component forming composition is improved, and the resolution is improved, and the line width change of the optical component forming composition due to the fluctuation of the waiting time before radiation irradiation and the waiting time after radiation irradiation can be suppressed, resulting in extremely excellent process stability.

(Other Components (F))
To the optical part forming composition of this embodiment, one or more of various additives such as a dissolution promoter, a dissolution controller, a sensitizer, a surfactant, and an organic carboxylic acid or a phosphorus oxo acid or a derivative thereof can be added as other components (F) as necessary within a range that does not impair the object of this embodiment. The other components (F) can be, for example, the same as the other components (F) that can be included in the lithography material composition of this embodiment described above.

The total content of other components (F) is preferably 0 to 49 mass% of the total mass of the solid components, more preferably 0 to 5 mass%, even more preferably 0 to 1 mass%, and particularly preferably 0 mass%.

In the optical component forming composition of this embodiment, the content of the compound represented by formula (X) and the resin containing the structural unit derived from the compound, the acid generator (C), the acid diffusion controller (E), and the other components (F) (resin containing the compound represented by formula (X) and the structural unit derived from the compound/acid generator (C)/acid diffusion controller (E)/other components (F)) is preferably 50 to 99.4/0.001 to 49/0.001 to 49/0 to 49, more preferably 55 to 90/1 to 40/0.01 to 10/0 to 5, even more preferably 60 to 80/3 to 30/0.01 to 5/0 to 1, and particularly preferably 60 to 70/10 to 25/0.01 to 3/0, in mass % based on solids. The content ratio of each component is selected from each range so that the sum of the components is 100 mass %. When the content ratio is set as above, the performance such as sensitivity, resolution, and developability is further improved.

The method for preparing the optical component forming composition of this embodiment is not particularly limited, and examples include a method in which each component is dissolved in a solvent at the time of use to form a homogeneous solution, and then, if necessary, filtered using a filter having a pore size of, for example, about 0.2 μm.

The optical component forming composition of this embodiment may contain a resin to the extent that the object of the present invention is not hindered. The resin is not particularly limited, and examples thereof include novolac resin, polyvinylphenols, polyacrylic acid, polyvinyl alcohol, styrene-maleic anhydride resin, and polymers containing acrylic acid, vinyl alcohol, or vinylphenol as monomer units, or derivatives thereof. The content of the resin is not particularly limited, and is appropriately adjusted depending on the type of compound represented by formula (X) used or the resin containing a structural unit derived from the compound, but is preferably 30 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 0 parts by mass per 100 parts by mass of the compound and the resin.

The cured product of this embodiment is obtained by curing the optical component-forming composition and can be used as various resins. These cured products can be used for various applications as highly versatile materials that impart various properties such as a high melting point, a high refractive index, and high transparency. The cured products can be obtained by subjecting the composition to light irradiation, heating, or other known methods corresponding to each composition.

These cured products can be used as various synthetic resins such as epoxy resin, polycarbonate resin, acrylic resin, etc., and furthermore, by utilizing their functionality, they can be used as optical components such as lenses and optical sheets.

In this specification, unless otherwise defined, "substituted" means that one or more hydrogen atoms in a functional group are substituted with a halogen atom, a hydroxyl group, a cyano group, a nitro group, a heterocyclic group, a linear aliphatic hydrocarbon group having 1 to 20 carbon atoms, a branched aliphatic hydrocarbon group having 3 to 20 carbon atoms, a cyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 30 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an acyl group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, an alkyloxy group having 1 to 20 carbon atoms, an aryloyloxy group having 7 to 30 carbon atoms, or an alkylsilyl group having 1 to 20 carbon atoms.

Examples of unsubstituted linear aliphatic hydrocarbon groups having 1 to 20 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, hexadecyl, and octadecyl groups. Examples of substituted linear aliphatic hydrocarbon groups having 1 to 20 carbon atoms include fluoromethyl, 2-hydroxyethyl, 3-cyanopropyl, and 20-nitrooctadecyl groups.

Examples of unsubstituted branched aliphatic hydrocarbon groups having 3 to 20 carbon atoms include isopropyl, isobutyl, tertiary butyl, neopentyl, 2-hexyl, 2-octyl, 2-decyl, 2-dodecyl, 2-hexadecyl, and 2-octadecyl groups. Examples of substituted branched aliphatic hydrocarbon groups having 3 to 20 carbon atoms include 1-fluoroisopropyl and 1-hydroxy-2-octadecyl groups.

Examples of unsubstituted cyclic aliphatic hydrocarbon groups having 3 to 20 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclodecyl, cyclododecyl, cyclohexadecyl, and cyclooctadecyl groups. Examples of substituted cyclic aliphatic hydrocarbon groups having 3 to 20 carbon atoms include 2-fluorocyclopropyl and 4-cyanocyclohexyl groups.

Examples of unsubstituted aryl groups having 6 to 20 carbon atoms include phenyl and naphthyl groups. Examples of substituted aryl groups having 6 to 20 carbon atoms include 4-isopropylphenyl, 4-cyclohexylphenyl, 4-methylphenyl, and 6-fluoronaphthyl groups.

Examples of unsubstituted alkenyl groups having 2 to 20 carbon atoms include vinyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, decynyl, dodecynyl, hexadecynyl, and octadecynyl groups. Examples of substituted alkenyl groups having 2 to 20 carbon atoms include chloropropynyl groups.

Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

The present embodiment will be described in more detail below with reference to examples. However, the present invention is not limited to these examples.

The structure of the compound was confirmed by ¹ H-NMR measurement under the following conditions using an Advance 600II spectrometer manufactured by Bruker.
(Measurement conditions for ¹ H-NMR measurement)
Frequency: 400MHz
Solvent: d-DMSO
Internal standard: tetramethylsilane

[Synthesis Example 1-1]
2.7 g (10 mmol) of _TeCl4 and 1.5 g (10 mol) of biphenyl were subjected to a condensation reaction in ₂₀ g of _CHCl3 in the presence of 3.1 g of AlCl3 catalyst at 60°C for 48 hours to obtain the compound A shown below in a yield of 61%. The molecular weight of the obtained compound A was measured by the following measurement method (GPC-MS) and found to be 356.
(GPC-MS measurement method)
Equipment: “ACQUITY UPLC H-Class” manufactured by Waters
Column: Waters "ACQUITY APC column"
Eluent: Tetrahydrofuran

[Synthesis Example 1-2]
Compound A (7.12 g, 20 mmol) was charged in a 50 mL vessel, 10.8 g (100 mmol) of anisole was added, and the reaction was carried out at 160 ° C. for 6 hours under reflux conditions. The obtained product was dried under reduced pressure, and recrystallized twice using acetonitrile, and filtered to obtain orange crystals. The obtained crystals were dried under reduced pressure for 24 hours, and then the entire amount of the dried crystals and 18 ml of methylene dichloride were added to a vessel with an internal volume of 100 mL equipped with a stirrer, a cooling tube, and a burette, and 3.9 g (15.75 mmol) of boron tribromide was added dropwise, and the reaction was carried out at -20 ° C. for 48 hours. The solution after the reaction was dropped into a 0.5 N hydrochloric acid solution in an ice bath, and after filtration, a yellow solid was collected. The obtained solid was dissolved in ethyl acetate, magnesium sulfate was added, and the mixture was dehydrated, concentrated, and separated and purified by column chromatography to obtain 0.2 g of compound A2.
The molecular weight of the obtained compound A2 was measured by the above-mentioned measurement method (GPC-MS) and was found to be 466. Furthermore, when the obtained compound A2 was subjected to NMR measurement under the above-mentioned measurement conditions, the following peaks were found and it was confirmed that the compound A2 had the chemical structure shown below.
δ (ppm) 10.2 (2H, -OH), 6.8 to 7.8 (16H, Ph-H)

[Synthesis Examples 1-3]
In a 200 mL volume vessel equipped with a stirrer, a cooling tube, and a buret, 4.7 g (10 mmol) of the compound A2, 0.30 g (22 mmol) of potassium carbonate, and 0.64 g (2 mmol) of tetrabutylammonium bromide were dissolved in 50 ml of N-methylpyrrolidone and stirred for 2 hours. After stirring, 6.3 g (22 mmol) of 2-methyladamantan-2-yl bromoacetate was further added and reacted at 100° C. for 24 hours. After the reaction was completed, the mixture was dropped into a 1N aqueous hydrochloric acid solution, and the resulting black solid was filtered off and separated and purified by column chromatography to obtain 1.9 g of compound A2-ADBAC.
The molecular weight of the obtained compound A2-ADBAC was measured by the above-mentioned measurement method (GPC-MS) and was found to be 882. In addition, when the obtained compound A2-ADBAC was subjected to NMR measurement under the above-mentioned measurement conditions, the following peaks were found and it was confirmed that the compound had the chemical structure shown below.
δ (ppm) 6.8 to 8.1 (16H, Ph-H), 4.7 to 5.0 (4H, O-CH ₂ -C (=O)-), 1.2 to 2.7 (34H, C-H/Adamantane of methylene and methine)

[Synthesis Examples 1-4]
In a 200 mL volume vessel equipped with a stirrer, a cooling tube, and a buret, 4.7 g (10 mmol) of the compound A2 and 5.5 g (25 mmol) of di-t-butyl dicarbonate (manufactured by Aldrich) were dissolved in 50 ml of N-methylpyrrolidone, and 0.30 g (22 mmol) of potassium carbonate was added and reacted for 24 hours at 100° C. After completion of the reaction, the mixture was dropped into a 1N aqueous hydrochloric acid solution, and the resulting black solid was filtered off and separated and purified by column chromatography to obtain 1.0 g of compound A2-BOC.
The molecular weight of the obtained compound A2-BOC was measured by the above-mentioned measurement method (GPC-MS) and found to be 698. Furthermore, when the obtained compound A2-BOC was subjected to NMR measurement under the above-mentioned measurement conditions, the following peaks were found and it was confirmed that the compound had the chemical structure shown below.
δ (ppm) 7.1 to 7.3 (16H, Ph-H), 1.4 (18H, C-C H ₃ )

[Synthesis Examples 1-5]
Compound A (7.12 g, 20 mmol) was charged in a 200 mL vessel, 2,7-dimethoxynaphthalene 75.32 g (40 mmol) and N,N-dimethylacetamide 50 mL were added, and the reaction was carried out at 160° C. for 6 hours under reflux conditions. Then, 100 ml of hexane was added, and the solid obtained by reprecipitation was filtered and dried under reduced pressure for 24 hours to obtain 10.30 g of an orange solid. Next, the entire amount of the dried solid and 18 ml of methylene dichloride were added to a vessel having an internal volume of 100 mL equipped with a stirrer, a cooling tube, and a burette, and 3.90 g (15.75 mmol) of boron tribromide was added dropwise, and the reaction was carried out at −20° C. for 48 hours. The solution after the reaction was added dropwise to a 0.5 N hydrochloric acid solution in an ice bath, and after filtration, a yellow solid was collected. The obtained solid was dissolved in ethyl acetate, magnesium sulfate was added, and after dehydration treatment, the mixture was dropped into hexane to obtain 9.43 g of resin P-A-DHN represented by the following formula. The molecular weight of the obtained resin P-A-DHN was measured by the above-mentioned measurement method (GPC-MS) and found to be 2135.

[Synthesis Example 2-1]
2.7 g (10 mmol) of _TeCl4 and 1.7 g (10 mmol) of diphenyl ether were subjected to a condensation reaction in ₂₀ g of _CHCl3 in the presence of 3.1 g of AlCl3 catalyst at 60°C for 48 hours to obtain the compound B shown below in a yield of 91%. The molecular weight of the obtained compound B was measured by the above-mentioned measurement method (GPC-MS) and found to be 368.

[Synthesis Example 2-2]
A 50 mL container was charged with 7.36 g (20 mmol) of the compound B instead of the compound A, and the same operation as in Synthesis Example 1-2 was carried out to obtain 0.3 g of compound B2. The molecular weight of the obtained compound B2 was measured by the above-mentioned measurement method (GPC-MS), and was found to be 486. In addition, when the obtained compound B2 was subjected to NMR measurement under the above-mentioned measurement conditions, the following peaks were found, and it was confirmed that the compound B2 had the chemical structure shown below.
δ (ppm) 10.3 (2H, -OH), 6.8 to 7.8 (16H, Ph-H)

[Synthesis Example 2-3]
In a 200 mL volume vessel equipped with a stirrer, a cooling tube, and a buret, 4.9 g (10 mmol) of the compound B2 was used instead of the compound A2, and the same operation as in Synthesis Example 1-3 was carried out to obtain 2.1 g of compound B2-ADBAC. The molecular weight of the obtained compound B2-ADBAC was measured by the above-mentioned measurement method (GPC-MS) and found to be 898. In addition, when the obtained compound B2-ADBAC was subjected to NMR measurement under the above-mentioned measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure shown below.
δ (ppm) 6.8 to 8.0 (16H, Ph-H), 4.7 to 5.0 (4H, O-CH ₂ -C (=O)-), 1.2 to 2.7 (34H, C-H/Adamantane of methylene and methine)

[Synthesis Example 2-4]
In a 200 mL volume vessel equipped with a stirrer, a cooling tube, and a buret, 2.0 g of compound B2-BOC was obtained by carrying out the same operations as in Synthesis Example 1-4, except that 4.9 g (10 mmol) of compound B2 was used instead of compound A2. The molecular weight of the obtained compound B2-BOC was measured by the above-mentioned measurement method (GPC-MS) and was found to be 714. In addition, when the obtained compound B2-BOC was subjected to NMR measurement under the above-mentioned measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure shown below.
δ (ppm) 7.1 to 7.3 (16H, Ph-H), 1.4 (18H, C-C H ₃ )

[Synthesis Example 2-5]
A 200 mL container was charged with 7.36 g (20 mmol) of the compound B instead of the compound A, and the same operation as in Synthesis Example 1-5 was carried out to obtain 8.56 g of a resin P-B-DHN represented by the following formula. The molecular weight of the obtained resin P-B-DHN was measured by the above-mentioned measurement method (GPC-MS) and found to be 2223.

[Synthesis Example 3-1]
_2.7 g (10 mmol) of TeCl4 and 1.9 g (10 mol) of diphenyl sulfide were subjected to a condensation reaction in ₂₀ g of CHCl3 in the presence of 3.1 g of _AlCl3 catalyst at 60°C for 48 hours to obtain the compound C shown below in a yield of 64%. The molecular weight of the obtained compound C was measured by the above-mentioned measurement method (GPC-MS) and found to be 384.

[Synthesis Example 3-2]
A 50 mL container was charged with 7.68 g (20 mmol) of the compound C instead of the compound A, and the same operation as in Synthesis Example 1-2 was carried out to obtain 0.4 g of compound C2. The molecular weight of the obtained compound C2 was measured by the above-mentioned measurement method (GPC-MS), and was found to be 502. In addition, when the obtained compound C2 was subjected to NMR measurement under the above-mentioned measurement conditions, the following peaks were found, and it was confirmed that the compound C2 had the chemical structure shown below.
δ (ppm) 10.3 (2H, -OH), 6.8 to 7.8 (16H, Ph-H)

[Synthesis Example 3-3]
In a 200 mL volume vessel equipped with a stirrer, a cooling tube, and a buret, 2.3 g of the following compound C2-ADBAC was obtained by carrying out the same operations as in Synthesis Example 1-3, except that 5.0 g (10 mmol) of the compound C2 was used instead of the compound A2. The molecular weight of the obtained compound C2-ADBAC was measured by the above-mentioned measurement method (GPC-MS) and was found to be 914. In addition, when the obtained compound C2-ADBAC was subjected to NMR measurement under the above-mentioned measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure shown below.
δ (ppm) 6.8-8.1 (16H, Ph-H), 4.7-5.0 (4H, O-CH ₂ -C (=O)-), 1.2-2.6 (34H, CH / Adamantane of methylene and methine)

[Synthesis Example 3-4]
In a 200 mL volume vessel equipped with a stirrer, a cooling tube, and a buret, 2.5 g of the following compound C2-BOC was obtained by carrying out the same operations as in Synthesis Example 1-4, except that 5.0 g (10 mmol) of the compound C2 was used instead of the compound A2. The molecular weight of the obtained compound C2-BOC was measured by the above-mentioned measurement method (GPC-MS) and was found to be 730. In addition, when the obtained compound C2-BOC was subjected to NMR measurement under the above-mentioned measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure shown below.
δ (ppm) 7.1 to 7.3 (16H, Ph-H), 1.5 (18H, C-C H ₃ )

[Synthesis Examples 3-5]
A 200 mL container was charged with 10.4 g (20 mmol) of the compound C instead of the compound A, and the same operation as in Synthesis Example 1-5 was carried out to obtain 8.96 g of a resin P-C-DHN represented by the following formula. The molecular weight of the obtained resin P-C-DHN was measured by the above-mentioned measurement method (GPC-MS) and found to be 1223.

[Synthesis Example 4]
A condensation reaction was carried out between _4.5 g (10 mmol) of TeBr4 and 1.5 g (10 mol) of biphenyl in the presence of 3.1 g of _AlCl3 catalyst in 20 _g of CHCl3 at 60 °C for 48 hours to obtain the compound D shown below in a yield of 50%.

[Synthesis Example 5]
_6.4 g (10 mmol) of TeI4 and 1.5 g (10 mol) of biphenyl were subjected to a condensation reaction in ₂₀ g of _CHCl3 in the presence of 3.1 g of AlCl3 catalyst at 60 °C for 48 hours to obtain the compound E shown below in a yield of 45%.

[Comparative Synthesis Example 1]
A four-neck flask with a capacity of 10 L and equipped with a Dimroth condenser, a thermometer and a stirring blade, which can be opened from the bottom, was prepared. In this four-neck flask, 1.09 kg (7 mol, manufactured by Mitsubishi Gas Chemical Co., Ltd.), 2.1 kg of 40 mass% formalin aqueous solution (28 mol as formaldehyde, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 0.97 mL of 98 mass% sulfuric acid (manufactured by Kanto Chemical Co., Ltd.) were charged in a nitrogen gas flow, and the mixture was reacted for 7 hours while refluxing at 100°C under normal pressure. Thereafter, 1.8 kg of ethylbenzene (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) was added as a dilution solvent to the reaction solution, and after standing, the aqueous phase of the lower phase was removed. Further, neutralization and washing with water were performed, and ethylbenzene and unreacted 1,5-dimethylnaphthalene were distilled off under reduced pressure to obtain 1.25 kg of dimethylnaphthalene formaldehyde resin as a light brown solid.

Next, a four-neck flask with an internal volume of 0.5 L equipped with a Dimroth condenser, a thermometer, and a stirring blade was prepared. 100 g (0.51 mol) of the dimethylnaphthalene formaldehyde resin and 0.05 g of paratoluenesulfonic acid were charged into this four-neck flask under a nitrogen gas flow, and the temperature was raised to 190°C and heated for 2 hours, after which the mixture was stirred. 52.0 g (0.36 mol) of 1-naphthol was then added, and the temperature was raised to 220°C and reacted for 2 hours. After dilution with the solvent, neutralization and washing with water were performed, and the solvent was removed under reduced pressure to obtain 126.1 g of compound CR-1, a modified resin in the form of a black-brown solid.

[Comparative Synthesis Example 2]
In a 200 mL volume vessel equipped with a stirrer, a cooling tube, and a buret, 10 g of the compound CR-1, 5.5 g (25 mmol) of di-t-butyl dicarbonate (manufactured by Aldrich) were charged in 100 mL of acetone, 3.45 g (25 mmol) of potassium carbonate (manufactured by Aldrich) was added, and the contents were stirred at 20° C. for 6 hours to carry out a reaction to obtain a reaction solution. Next, the reaction solution was concentrated, and 100 g of pure water was added to the concentrated solution to precipitate the reaction product, which was then cooled to room temperature and filtered to separate the solid matter. The obtained solid matter was washed with water and dried under reduced pressure to obtain 4 g of compound CR-1-BOC, which is a black solid modified resin.

[Examples 1 to 12, Comparative Examples 1 and 2]
(Preparation of resist composition)
Using the compounds and resins synthesized in the Synthesis Examples and Comparative Synthesis Examples, resist compositions were prepared according to the formulations shown in Table 1. Of the components of the resist composition in Table 1, the acid generator, acid crosslinker, acid diffusion controller, and solvent used were as follows.
Acid generator: Triphenylbenzenesulfonium trifluoromethanesulfonate (Midori Chemical Co., Ltd.)
Acid crosslinking agent: Trade name "Nicalac MX270 (Nicalac)" manufactured by Sanwa Chemical Co., Ltd. Acid diffusion control agent: Trioctylamine (manufactured by Tokyo Chemical Industry Co., Ltd.)
Solvent: Propylene glycol monomethyl ether acetate (Tokyo Chemical Industry Co., Ltd.)

(Evaluation of resist characteristics)
(1) Evaluation of Solubility of Compounds and Resins in Safe Solvents The solubility of compounds and resins in safe solvents was measured by measuring the solubility of the compounds and resins in propylene glycol monomethyl ether acetate. The solubility was evaluated according to the following criteria using the amount dissolved in propylene glycol monomethyl ether acetate. The amount dissolved was measured at 23°C. The compound or resin was precisely weighed in a test tube, propylene glycol monomethyl ether acetate was added to a predetermined concentration, and ultrasonic waves were applied for 30 minutes in an ultrasonic cleaner. The state of the liquid after that was visually observed, and the amount completely dissolved was used to evaluate according to the following criteria. The results are shown in Table 1.
A: 5.0 mass%≦dissolution amount B: 3.0 mass%≦dissolution amount<5.0 mass%
C: Dissolved amount <3.0% by mass

(2) Evaluation of storage stability and thin film formation of resist composition The storage stability of the resist composition was evaluated by preparing the resist composition, leaving it at rest for 3 days at 23° C., and visually observing whether precipitation occurred. After leaving it at rest for 3 days, the resist composition was rated as "A" if it was a homogeneous solution and no precipitation occurred, and was rated as "C" if precipitation was observed.
The thin film formation of the resist composition was evaluated by the following method. A uniform resist composition was spin-coated on a clean silicon wafer, and then pre-baked (PB) in an oven at 110° C. to form a resist film with a thickness of 40 nm. When the thin film formation was good, it was rated as "A", and when the formed film had defects, it was rated as "C". The results are shown in Table 1.

(3) Evaluation of the sensitivity and pattern shape of the resist composition A uniform resist composition was spin-coated on a clean silicon wafer, and then pre-exposure baked (PB) in an oven at 110° C. to form a resist film with a thickness of 60 nm. The obtained resist film was irradiated with an electron beam in a line-and-space setting of 1:1 with a 50 nm interval using an electron beam lithography device (product name: ELS-7500, manufactured by Elionix Co., Ltd.). After the irradiation, the resist film was heated at a predetermined temperature for 90 seconds, and developed by immersing it in an alkaline developer containing 2.38 mass % of tetramethylammonium hydroxide (TMAH) for 60 seconds. Thereafter, the resist film was washed with ultrapure water for 30 seconds and dried to form a positive resist pattern. The lines and spaces of the formed resist pattern were observed using a scanning electron microscope ("S-4800" manufactured by Hitachi High-Technologies Co., Ltd.) to evaluate the reactivity (sensitivity) of the resist composition due to electron beam irradiation. The sensitivity is indicated by the minimum amount of energy per unit area required to obtain the pattern, and when a pattern was obtained at less than 50 μC/cm ² , it was rated as "A", and when a pattern was obtained at 50 μC/cm ² or more, it was rated as "C". The obtained pattern shape was observed with a SEM (scanning electron microscope), and when a rectangular pattern was obtained, it was rated as "A", when a nearly rectangular pattern was obtained, it was rated as "B", and when a non-rectangular pattern was obtained, it was rated as "C". The results are shown in Table 1. In addition, in Examples 2, 3, 5, 6, 8 and 9 and Comparative Example 2, positive resist patterns were formed, and in Examples 1, 4 and 7 and Comparative Example 1, negative resist patterns were formed.

As can be seen from Table 1, it was confirmed that the compounds or resins used in Examples 1 to 12 have excellent solubility in safe solvents equivalent to the compounds used in Comparative Examples 1 and 2. It was also confirmed that the resist compositions of Examples 1 to 12 have excellent storage stability and thin film formability equivalent to the resist compositions of Comparative Examples 1 and 2. Furthermore, it was confirmed that the resist compositions of Examples 1 to 12 have superior sensitivity and pattern shape to the resist compositions of Comparative Examples 1 and 2.

The above results show that compounds and resins that satisfy the requirements of the present invention have high solubility in safe solvents, and resist compositions containing such compounds and resins have better storage stability, are capable of forming thin films, and are highly sensitive as well as capable of imparting excellent resist pattern shapes, compared to resist compositions containing comparative compounds (CR-1 and CR-1-BOC). As long as they satisfy the above-mentioned requirements of the present invention, compounds and resins other than those described in the examples also show the same effects.

[Examples 13 to 48, Comparative Example 3]
(Preparation of composition for forming resist underlayer film)
Using the compounds and resins synthesized in the Synthesis Examples and Comparative Synthesis Examples, compositions for forming resist underlayer films were prepared according to the formulations shown in Table 2. Among the components of the compositions for forming resist underlayer films in Table 2, the acid generators, acid crosslinkers, and organic solvents used were as follows.
Acid generator: di-tertiary butyl diphenyl iodonium nonafluoromethanesulfonate (DTDPI) (manufactured by Midori Chemical Co., Ltd.)
Acid crosslinking agent: Trade name "Nicalac MX270 (Nicalac)" manufactured by Sanwa Chemical Co., Ltd. Organic solvent: Propylene glycol monomethyl ether acetate (PGMEA)

(Evaluation of Etching Resistance)
The resist underlayer film-forming compositions of Examples 13 to 48 and Comparative Example 3 were spin-coated on a silicon substrate and then baked at 240° C. for 60 seconds to prepare underlayer films having a thickness of 200 nm. Then, an etching test was carried out under the conditions shown below, and the etching rate at that time was measured.

<Etching test conditions>
Etching equipment: Product name "RIE-10NR", manufactured by Samco International, Inc. Output: 50 W
Pressure: 20 Pa
Time: 2 minutes
Etching gas: Ar gas flow rate: _CF4 gas flow rate: _O2 gas flow rate = 50:5:5 (sccm)

The etching resistance was evaluated as follows. A novolac underlayer film was prepared under the same conditions as in Example 13, except that novolac (trade name "PSM4357", manufactured by Gun-ei Chemical Co., Ltd.) was used instead of the compound A2 used in Example 13. The above-mentioned etching test was then performed on this novolac underlayer film, and the etching rate was measured. The etching resistance was evaluated according to the following evaluation criteria, based on the etching rate.
<Evaluation criteria>
A: The etching rate is less than -10% compared to the underlayer film of novolac.
B: The etching rate is −10% to +5% compared to the novolac underlayer film.
C: The etching rate is more than +5% compared to the underlayer film of novolac.

As shown in Table 2, it was confirmed that the underlayer films of Examples 13 to 48 have higher etching resistance than the underlayer film of Comparative Example 3.

[Example 49]
(Formation of Resist Pattern)
The resist underlayer film forming composition of Example 13 was applied onto a SiO ₂ substrate having a thickness of 300 nm, and baked at 240° C. for 60 seconds and then at 400° C. for 120 seconds to form a resist underlayer film having a thickness of 85 nm. An ArF resist solution was applied onto this underlayer film, and baked at 130° C. for 60 seconds to form a photoresist layer having a thickness of 140 nm. The ArF resist solution was prepared by mixing 1 part by mass of the compound CR-1A shown below, 1 part by mass of triphenylsulfonium nonafluoromethanesulfonate, 2 parts by mass of tributylamine, and 30 parts by mass of propylene glycol monomethyl ether.

Compound CR-A1 was synthesized as follows. Anhydrous HF 74.3g (3.71 mol) and BF ₃ 50.5g (0.744 mol) were charged into a temperature-controllable 500mL internal volume electromagnetic stirring autoclave (SUS316L), the contents were stirred, and the liquid temperature was kept at -30°C while the pressure was increased to 2MPa with carbon monoxide. Then, while keeping the pressure at 2MPa and the liquid temperature at -30°C, a raw material mixture of 4-cyclohexylbenzene 57.0g (0.248 mol) and n-heptane 50.0g was supplied and maintained for 1 hour. The contents were then collected and placed in ice, diluted with benzene, and the oil layer obtained by neutralization was analyzed by gas chromatography. The conversion rate of 4-cyclohexylbenzene was 100%, and the selectivity of 4-cyclohexylbenzaldehyde was 97.3%.

The target component was isolated by simple distillation and analyzed by GC-MS, which showed that the molecular weight of the target substance, 4-cyclohexylbenzaldehyde (hereafter also referred to as "CHBAL"), was 188. The molecular weight was measured using a GC-MS (product name "QP2010 Ultra") manufactured by Shimadzu Steel Works. The chemical shift values of 1H-NMR (δ ppm, TMS standard) in deuterated chloroform solvent were 1.0-1.6 (m, 10H), 2.6 (m, 1H), 7.4 (d, 2H), 7.8 (d, 2H), and 10.0 (s, 1H).

A four-neck flask (1000 mL) equipped with a dropping funnel, a Jim Roth condenser, a thermometer, and a stirring blade that had been thoroughly dried and replaced with nitrogen was charged with Kanto Chemical's resorcinol (22 g, 0.2 mol), the above-mentioned 4-cyclohexylbenzaldehyde (46.0 g, 0.2 mol), and dehydrated ethanol (200 mL) under a nitrogen stream to prepare an ethanol solution. This solution was heated to 85°C with a mantle heater while stirring. Next, 75 mL of concentrated hydrochloric acid (35%) was added dropwise using the dropping funnel over 30 minutes, and then stirred at 85°C for 3 hours. After the reaction was completed, the mixture was allowed to cool and reach room temperature, and then cooled in an ice bath. After standing for 1 hour, pale yellow crude crystals of the desired product were produced, which were filtered off. The crude crystals were washed twice with 500 mL of methanol, filtered, and vacuum dried to obtain 50 g of product. The structure of this product was analyzed by GPC-MS, and the molecular weight was 1121. The chemical shift values (δ ppm, TMS standard) of 1H-NMR in deuterated chloroform solvent were 0.8-1.9 (m, 44H), 5.5, 5.6 (d, 4H), 6.0-6.8 (m, 24H), and 8.4, 8.5 (m, 8H). From these results, the obtained product was identified as the target compound (compound CR-1A) (yield 91%).

The photoresist layer was then exposed to light using an electron beam lithography system (Elionix, trade name "ELS-7500", 50 keV), baked at 115°C for 90 seconds (PEB), and developed with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) for 60 seconds to obtain positive resist patterns of 45 nm L/S (1:1) and 80 nm L/S (1:1).

(evaluation)
The shape of the obtained resist pattern was observed using an electron microscope (product name "S-4800") manufactured by Hitachi, Ltd. Regarding the shape of the resist pattern after development, those that had no pattern collapse and good rectangularity were rated as "good", and those that did not were rated as "bad". Furthermore, as a result of the observation, the minimum line width at which there was no pattern collapse and good rectangularity was used as an index of evaluation as "resolution". Furthermore, the minimum amount of electron beam energy capable of drawing a good pattern shape was used as an index of evaluation as "sensitivity". The results are shown in Table 3.

[Comparative Example 4]
A photoresist layer was formed directly on a _SiO2 substrate in the same manner as in Example 49, except that no resist underlayer film was formed, to obtain a positive resist pattern. The resist pattern was evaluated in the same manner as in Example 49. The results are shown in Table 3.

As is clear from Table 3, the resist underlayer film in Example 49 using the resist underlayer film forming composition of the present invention was confirmed to be significantly superior in both resolution and sensitivity compared to Comparative Example 4. In addition, the resist underlayer film in Example 49 was confirmed to have excellent heat resistance and no pattern collapse in the resist pattern shape after development and good rectangularity, so that the pattern does not droop when heated. Furthermore, the difference in the resist pattern shape after development showed that the resist underlayer film forming composition in Example 49 has excellent embedding properties in stepped substrates and film flatness, and has good adhesion to resist materials.

[Examples 50 to 85, Comparative Example 5]
Preparation of Optical Component Forming Composition
An optical component-forming composition was prepared so as to have the composition shown in Table 4. Of the components of the optical component-forming composition in Table 4, PGMEA was used as the organic solvent, DTDPI was used as the acid generator, and Nikalac was used as the acid crosslinking agent.

(Film formation evaluation)
The prepared homogeneous optical component forming composition was spin-coated on a clean silicon wafer, and then prebaked (PB) in an oven at 110° C. to form an optical component forming film having a thickness of 1 μm. When the film formation was good, it was rated as "A", and when the formed film had defects, it was rated as "C". The results are shown in Table 4.

(Refractive index and transparency evaluation)
The prepared uniform optical component forming composition was spin-coated on a clean silicon wafer, and then PB was performed in an oven at 110°C to form a film with a thickness of 1 μm. The refractive index (λ = 589.3 nm) of the film was measured at 25°C using a multi-angle incident spectroscopic ellipsometer VASE manufactured by J.A. Woollam. The prepared film was rated as "A" when the refractive index was 1.8 or more, "B" when it was 1.6 or more and less than 1.8, and "C" when it was less than 1.6. In addition, the transparency (λ = 632.8 nm) was rated as "A" when it was 90% or more, and "C" when it was less than 90%. The results are shown in Table 4.

As can be seen from Table 4, the optical component forming compositions of Examples 50 to 85 were capable of forming excellent films, and it was confirmed that the films had higher refractive index and transparency than those of Comparative Example 5.

The above results show that compounds and resins that satisfy the requirements of the present invention are highly soluble in organic solvents, and that optical component-forming compositions containing such compounds and resins are capable of forming films and imparting high refractive index and high transmittance. Compounds and resins other than those described in the examples also exhibit similar effects as long as they satisfy the above-mentioned requirements of the present invention.

[Example 86]
(Preparation of solutions with reduced metal content)
In a 1000 mL four-neck flask (bottom-opening type), 150 g of a solution in which the compound A2 was dissolved in PGMEA at 2.5% by mass was charged, and the solution was heated to 80° C. while stirring. Next, 37.5 g of an aqueous oxalic acid solution (pH 1.3) was added, stirred for 5 minutes, and then allowed to stand for 30 minutes. As a result, the oil phase and the aqueous phase were separated, and the aqueous phase was removed. After repeating this operation once, 37.5 g of ultrapure water was charged into the obtained oil phase, stirred for 5 minutes, and then allowed to stand for 30 minutes, and the aqueous phase was removed. This operation was repeated three times to obtain a PGMEA solution of compound A2 with a reduced metal content.

(Metal Content Measurement)
The contents of various metals in the solution were measured by ICP-MS (product name "ELAN DRCII", manufactured by PerkinElmer). The measurement results are shown in Table 5. Table 5 also shows the measurement results of a 10 mass % PGMEA solution of compound A2 before purification (hereinafter also referred to as A2 solution before purification), a 10 mass % PGMEA solution of compound A2-ADBAC before purification (hereinafter also referred to as A2-ADBAC solution before purification), and a 10 mass % PGMEA solution of compound A2-BOC before purification (hereinafter also referred to as A2-BOC solution before purification).

[Example 87]
Instead of charging 150 g of a solution in which compound A2 was dissolved at 2.5 mass % in PGMEA, 150 g of a solution in which compound A2 was dissolved at 10 mass % in PGMEA (120 g) / PGME (15 g) was charged, and the same treatment as in Example 86 was performed to obtain a PGMEA solution of compound A2 with a reduced metal content. The content of various metals in the solution was measured in the same manner as in Example 86. The results are shown in Table 5.

[Example 88]
A PGMEA solution of compound A2 having a reduced metal content was obtained by treating in the same manner as in Example 86, except that 130 g of a citric acid aqueous solution (pH 1.8) was used instead of 37.5 g of an oxalic acid aqueous solution (pH 1.3). The contents of various metals in the solution were measured in the same manner as in Example 86. The results are shown in Table 5.

[Example 89]
A PGMEA solution of compound A2-ADBAC having a reduced metal content was obtained by treating in the same manner as in Example 86, except that 150 g of a solution in which compound A2-ADBAC was dissolved in PGMEA at 2.5 mass % was charged instead of 150 g of a solution in which compound A2-ADBAC was dissolved in PGMEA at 2.5 mass %. The contents of various metals in the solution were measured in the same manner as in Example 86. The results are shown in Table 5.

[Example 90]
A PGMEA solution of compound A2-BOC having a reduced metal content was obtained by treating in the same manner as in Example 86, except that 150 g of a solution in which compound A2-BOC was dissolved in PGMEA at 2.5 mass % was charged instead of 150 g of a solution in which compound A2-BOC was dissolved in PGMEA at 2.5 mass %. The contents of various metals in the solution were measured in the same manner as in Example 86. The results are shown in Table 5.

As can be seen from Table 5, the metal content in the solutions of Examples 86 to 90 purified by the purification method of the present invention was effectively reduced compared to each solution before purification.

Claims (24)

A compound represented by the following formula (X):
In formula (X), _X0 is a group represented by the following formula ( 1A ), Y is a single bond, an oxygen atom or a sulfur atom , each ^P0 is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group or a halogen atom, each q is independently an integer from 0 to 3, and each v is independently an integer from 0 to (4+2×q) .
(In formula (1A), each p is independently an integer of 0 to 3; each R ¹ is independently a hydrocarbon group; a halogen atom; a cyano group; a nitro group; an amino group; an alkyl group having 1 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond; an alkenyl group having 2 to 30 carbon atoms and containing an ether bond, a ketone bond or an ester bond; or an aryl group having 6 to 40 carbon atoms and containing an ether bond, a ketone bond or an ester bond; each R ² is independently a hydrogen atom, a crosslinkable reactive group or a dissociable reactive group; each n ¹ is independently an integer of 0 to (5+2×p); and each n ² is independently an integer of 0 to (5+2×p). However, at least one n ² is an integer from 1 to (5+2×p). * indicates connection to Te. The crosslinkable reactive group is an allyl group, a (meth)acryloyl group, a vinyl group, an epoxy group, an alkoxymethyl group, or a cyano group. The dissociable reactive group is a substituted methyl group, a 1-substituted ethyl group, a 1-substituted n-propyl group, a 1-branched alkyl group, a silyl group, an acyl group, a 1-substituted alkoxymethyl group, a cyclic ether group, an alkoxycarbonyl group, or an alkoxycarbonylalkyl group that has the property of being dissociated by an acid. The compound according to claim 1 , wherein in said formula (1A) , each R ¹ is independently the hydrocarbon group which is an alkyl group, an aryl group or an alkenyl group, or the halogen atom. The compound according to claim 1 or 2 , wherein in formula (1A) , p is 0. The compound according to any one of claims 1 to 3 , wherein in the formula (1A) , ⁿ¹ and ⁿ² are 1. The compound according to any one of claims 1 to 4 , wherein in said formula (1A) , at least one ^R2 is a dissociable reactive group. The compound according to any one of claims 1 to 4 , wherein in said formula (1A) , all of said R ² 's are hydrogen atoms. A resin containing a structural unit represented by the following formula (B1-M):
(In formula (B1-M), each R ³ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; s is an integer from 0 to 3; and n ³ is 0 to (4+2×s). Each Y is a single bond, an oxygen atom, or a sulfur atom; each P ⁰ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; each q is independently an integer from 0 to 3; and each v is independently an integer from 0 to (4+2×q). R ⁴ is a group represented by the following formula (5).)
(In formula (5), R ⁵ is a substituted or unsubstituted linear alkylene group having 1 to 20 carbon atoms, a branched alkylene group having 3 to 20 carbon atoms, or a cyclic alkylene group having 3 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and each R ^5' is independently any group of the following formula (5').)
(In formula (5'), * indicates connection to ^R5 .) A resin containing a structural unit represented by the following formula (B2-M'):
(In formula (B2-M'), each R ³ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; s is an integer from 0 to 3; and n ³ is 0 to (4+2×s). Each Y is a single bond, an oxygen atom, or a sulfur atom; each P ⁰ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; each q is independently an integer from 0 to 3; and each v is independently an integer from 0 to (4+2×q). R ⁶ is a substituted or unsubstituted linear, branched, or cyclic trivalent aliphatic group having 1 to 20 carbon atoms, or a substituted or unsubstituted trivalent aromatic group having 6 to 20 carbon atoms; R Each ^6' is independently any group of the following formula (6'):
(In formula (6'), * indicates connection to ^R6 .) A resin comprising a structural unit represented by the following formula (C1):
(In formula (C1), each R ⁷ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; r is an integer from 0 to 3; and n ⁷ is 2 to (4+2×r) ; each Y is a single bond, an oxygen atom, or a sulfur atom; each P ⁰ is independently a monovalent group containing an oxygen atom, a monovalent group containing a sulfur atom, a monovalent group containing a nitrogen atom, a hydrocarbon group, or a halogen atom; each q is independently an integer from 0 to 3; and each v is independently an integer from 0 to (4+2×q). ) A composition comprising the compound according to any one of claims 1 to 6 or the resin according to any one of claims 7 to 9 . The composition of claim 10 further comprising a solvent. The composition according to claim 10 or 11 , further comprising an acid generator. The composition according to claim 10 , further comprising an acid crosslinking agent. The composition of claim 10 further comprising a diazonaphthoquinone photoactive compound. A resist film formed from the composition according to any one of claims 10 to 14 . A film forming step of forming a film on a substrate using the composition according to any one of claims 10 to 14 ;
an exposure step of exposing the film to light;
a developing step for developing the film exposed in the exposure step to form a pattern;
A pattern forming method comprising the steps of: The composition according to claim 10 , further comprising a silicon-containing compound. The composition according to claim 17 , wherein the silicon-containing compound is a hydrolyzable organosilane, a hydrolyzate thereof, or a hydrolyzed condensate thereof. An underlayer film for lithography formed using the composition according to any one of claims 10 to 14 , 17 and 18 . An optical component formed using the composition according to any one of claims 10 to 14 . A step of dissolving the compound according to any one of claims 1 to 6 or the resin according to any one of claims 7 to 9 in a solvent containing an organic solvent that is arbitrarily immiscible with water to obtain a solution (A);
a first extraction step of contacting the obtained solution (A) with an acidic aqueous solution to extract impurities in the compound or the resin;
A method for purifying a compound or resin comprising: The method for purifying a compound or resin according to claim 21, wherein the acidic aqueous solution is an aqueous solution of one or more mineral acids selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid; or an aqueous solution of one or more organic acids selected from the group consisting of acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, tartaric acid, citric acid, methanesulfonic acid, phenolsulfonic acid, p-toluenesulfonic acid , and trifluoroacetic acid. The method for purifying a compound or resin according to claim 21 or 22, wherein the organic solvent which is arbitrarily immiscible with water is one or more organic solvents selected from the group consisting of toluene, 2 -heptanone, cyclohexanone, cyclopentanone, methyl isobutyl ketone , propylene glycol monomethyl ether acetate, and ethyl acetate. The method for purifying a compound or resin according to any one of claims 21 to 23 , further comprising a second extraction step of contacting the solution phase containing the compound or the resin with water after the first extraction step to extract impurities in the compound or the resin.