JP5851282B2 - Resist composition and resist pattern forming method - Google Patents

Description

  The present invention relates to a resist composition and a resist pattern forming method using the resist composition.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed and developed to form a resist pattern having a predetermined shape on the resist film. The process to perform is performed. A resist material in which the exposed portion of the resist film changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, generally, the exposure light source has a shorter wavelength (higher energy). Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. Further, studies have been made on EUV (extreme ultraviolet), EB (electron beam), X-rays, and the like having a shorter wavelength (higher energy) than these excimer lasers.
Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions.
Conventionally, as a resist material satisfying such requirements, a chemically amplified resist composition containing an acid generator component that generates an acid upon exposure and a base material component whose solubility in a developing solution is changed by the action of the acid. Is used.

As a base material component used in the chemically amplified resist composition, a resin (base resin) is generally used.
For example, as a chemically amplified resist composition for forming a positive resist pattern in an alkali development process using an alkali developer as a developer, an acid generator component and solubility in an alkali developer due to the action of an acid are included. What contains the resin component which increases is generally used. When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the acid generator component in the exposed portion, and the alkali developer of the resin component is generated by the action of the acid. As a result, the exposed area becomes soluble in an alkaline developer. Therefore, by performing alkali development, a positive pattern in which an unexposed portion remains as a pattern is formed.
As the resin component, one that increases the polarity of the resin by the action of an acid is generally used. As the polarity increases, solubility in an alkaline developer increases while solubility in an organic solvent decreases. Therefore, when a solvent development process using an organic solvent-containing developer (organic developer) is applied instead of an alkali development process, the solubility in the organic developer is relatively reduced in the exposed area. In the solvent development process, the unexposed portion of the resist film is dissolved and removed by the organic developer, and a negative resist pattern is formed in which the exposed portion remains as a pattern. Such a solvent development process for forming a negative resist pattern is sometimes referred to as a negative development process (see, for example, Patent Document 1).

  At present, as a base resin of a chemically amplified resist composition used in ArF excimer laser lithography and the like, it has a structural unit derived from (meth) acrylic acid ester in its main chain because of its excellent transparency near 193 nm. Resins (acrylic resins) and the like are generally used (see, for example, Patent Document 2). Here, “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position. “(Meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position.

JP 2009-25707 A JP 2011-102380 A

In the future, there is a demand for new materials that can be used for lithography applications as further progress in lithography technology and expansion of application fields progress.
For example, as the pattern becomes finer, the resist material also has resolution and roughness (LWR (line width roughness: line width non-uniformity) for line patterns), roundness for hole patterns, etc. ), Further improvement of various lithography properties such as exposure margin is required.
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a resist composition excellent in coatability, resolution, and lithography characteristics, and a resist pattern forming method using the resist composition. To do.

In order to solve the above problems, the present inventor has attempted to increase the polarity of the base resin that is a constituent of the resist composition. However, there is a problem that a highly polar base resin is hardly soluble in conventional organic solvents. This decrease in solubility leads to non-uniform application of the resist film, which may lead to deterioration of lithography properties and generation of defects during pattern formation. Therefore, the present invention employs the following configuration.
That is, the first aspect of the present invention includes a base material component (A) whose solubility in a developer is changed by the action of an acid, an acid generator component (B) that generates an acid upon exposure, and an organic solvent component (S). A resist composition comprising:
In the said organic solvent component (S) , the organic solvent (S1) which consists of a compound represented by the following general formula (s-1) is contained in the ratio of 5-80 mass% ,
The substrate component (A) contains a resin component (A0) having a structural unit (a2) containing a —SO ₂ -containing cyclic group, a carbonate-containing cyclic group, or a lactone-containing cyclic group. A resist composition.

  According to a second aspect of the present invention, a resist film is formed on a support using the resist composition of the first aspect, the resist film is exposed, and the resist film is developed to form a resist. It is a resist pattern formation method including the process of forming a pattern.

In the present specification and claims, “exposure” is a concept including general irradiation of radiation.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“Aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.
The “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group.
“Halogenated alkyl group” is a group in which some or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms. “Halogenated alkylene group” is a group in which some or all of the hydrogen atoms in the alkylene group are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Fluorinated alkyl group” is a group in which some or all of the hydrogen atoms in the alkyl group are substituted with fluorine atoms, and “fluorinated alkylene group” in which some or all of the hydrogen atoms in the alkylene group are substituted with fluorine atoms Group.

  ADVANTAGE OF THE INVENTION According to this invention, the resist composition excellent in applicability | paintability, resolution, and a lithography characteristic, and a resist pattern formation method can be provided.

≪Resist composition≫
The resist composition of the present invention comprises a base component (A) whose solubility in a developer is changed by the action of an acid (hereinafter referred to as “component (A)”), an acid generator component (B) that generates an acid upon exposure. ) (Hereinafter referred to as “component (B)”) and organic solvent component (S) (hereinafter referred to as “component (S)”).
When a resist film is formed using such a resist composition and selective exposure is performed on the resist film, an acid is generated from the component (B) in the exposed area, and the development of the component (A) is caused by the action of the acid. While the solubility in the liquid changes, the solubility of the component (A) in the developer does not change in the unexposed area, so that a difference in solubility in the developer occurs between the exposed area and the unexposed area. Therefore, when the resist film is developed, when the resist composition is positive, the exposed portion is dissolved and removed to form a positive resist pattern. When the resist composition is negative, the unexposed portion is dissolved and removed. As a result, a negative resist pattern is formed.
In this specification, a resist composition in which an exposed portion is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and a resist composition that forms a negative resist pattern in which an unexposed portion is dissolved and removed. Is referred to as a negative resist composition.
The resist composition of the present invention may be a positive resist composition or a negative resist composition.
In addition, the resist composition of the present invention may be used for an alkali development process using an alkali developer for development processing at the time of forming a resist pattern, and a developer (organic developer) containing an organic solvent is used for the development processing. It may be for the solvent development process used.

<(A) component>
The “base component” in the component (A) is an organic compound having a film forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
Organic compounds used as the base material component are roughly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, the “low molecular compound” refers to a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, those having a molecular weight of 1000 or more are usually used. Hereinafter, the term “resin” refers to a polymer having a molecular weight of 1000 or more.
As the molecular weight of the polymer, a polystyrene-reduced mass average molecular weight by GPC (gel permeation chromatography) is used.

When the resist composition of the present invention is a “negative resist composition for an alkali development process” that forms a negative resist pattern in an alkali development process (or “solvent development that forms a positive resist pattern in a solvent development process”). In the case of “a positive resist composition for a process”, the component (A) is preferably a base component (A2) (hereinafter referred to as “component (A2)”) that is soluble in an alkaline developer. Furthermore, a crosslinking agent component is blended. In such a resist composition, when an acid is generated by exposure, the acid acts to cause crosslinking between the component (A2) and the crosslinking agent component, resulting in a decrease in solubility in an alkaline developer (organic development). The solubility in the liquid increases). Therefore, in the formation of a resist pattern, when a resist film obtained by coating the resist composition on a support is selectively exposed, the exposed portion is hardly soluble in an alkali developer (to an organic developer). On the other hand, the unexposed area remains soluble (almost insoluble in the organic developer) while remaining undissolved in the alkali developer, so that a negative resist pattern can be formed by developing with an alkali developer. . At this time, if an organic developer is used as the developer, a positive resist pattern can be formed.
As the component (A2), a resin that is soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”) is used.
Examples of the alkali-soluble resin include α- (hydroxyalkyl) acrylic acid or α- (hydroxyalkyl) acrylic acid alkyl ester (preferably having 1 to 5 carbon atoms) disclosed in, for example, JP-A-2000-206694. A resin having a unit derived from at least one selected from alkyl ester); a hydrogen atom bonded to a carbon atom at the α-position having a sulfonamide group, which is disclosed in US Pat. No. 6,949,325, is substituted with a substituent. Acrylic resin or polycycloolefin resin that may be contained; disclosed in US Pat. No. 6,949,325; The hydrogen atom bonded to the atom may be substituted with a substituent. Le resin; Japanese Patent disclosed in 2006-259582, JP-polycycloolefin resins having fluorinated alcohol, with minimal swelling can formation of a satisfactory resist pattern.
The α- (hydroxyalkyl) acrylic acid is a hydrogen atom bonded to the α-position carbon atom to which the carboxy group is bonded, among the acrylic acid in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. One or both of acrylic acid having an atom bonded thereto and α-hydroxyalkylacrylic acid having a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) bonded to the α-position carbon atom are shown. .
As the crosslinking agent component, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, a melamine crosslinking agent, or the like because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent component is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the resist composition of the present invention is a resist composition that forms a positive pattern in an alkali development process and a negative pattern in a solvent development process, the component (A) has increased polarity due to the action of an acid. The base material component (A1) (hereinafter referred to as “component (A1)”) is used. By using the component (A1), the polarity of the base material component changes before and after exposure, so that good development contrast can be obtained not only in the alkali development process but also in the solvent development process.
When an alkali development process is applied, the component (A1) is hardly soluble in an alkali developer before exposure. When an acid is generated by exposure, the polarity increases due to the action of the acid, and the component (A1) Solubility increases. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the resist composition on a support is selectively exposed, the exposed portion changes from slightly soluble to soluble in an alkaline developer. Since the unexposed portion remains hardly soluble in alkali and does not change, a positive pattern can be formed by alkali development.
On the other hand, when the solvent development process is applied, the component (A1) is highly soluble in an organic developer before exposure, and when an acid is generated by exposure, the action of the acid increases the polarity. Solubility in system developers is reduced. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the resist composition on the support is selectively exposed, the exposed portion changes from soluble to poorly soluble in an organic developer. On the other hand, since the unexposed portion remains soluble and does not change, by developing with an organic developer, a contrast can be provided between the exposed portion and the unexposed portion, and a negative pattern can be formed.

[Resin component (A0)]
In the present invention, the component (A) is a resin component (A0) having a structural unit (a2) containing a —SO ₂ — containing cyclic group, a carbonate containing cyclic group, or a lactone containing cyclic group (hereinafter referred to as “(A0 ) ”Component)).
The component (A0) may be the component (A2) or the component (A1).

(Structural unit (a2))
The structural unit (a2) in the present invention is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and the —SO ₂ -containing cyclic group structural unit containing (a2 ^S), and a hydrogen atom bonded to the α-position carbon atom of a structural unit derived from an acrylate ester which may have substituted with a substituent structure containing a lactone-containing cyclic group Unit (a2 ^L ) or a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and including a carbonate-containing cyclic group ( it is preferred from the group consisting of a2 ^C) is at least one selected.
These cyclic groups improve the adhesion of the resist film formed using the resist composition containing the polymer of the present invention to the substrate, and a developer containing water (particularly in the case of an alkali development process). It contributes to the improvement of the lithography properties by increasing the affinity of.
These cyclic groups are effective in enhancing the adhesion of the resist film to the substrate when the component (A0) is used for forming the resist film. Moreover, it is effective in the alkali development process in that the affinity with a developer containing water such as an alkali developer is improved.

-Structural unit (a2 ^S ):
The structural unit (a2 ^S ) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and includes a —SO ₂ — containing cyclic group. It is a structural unit.
Here, -SO ₂ - and containing cyclic group, -SO ₂ - within the ring skeleton thereof shows a cyclic group containing a ring containing, in particular, -SO ₂ - in the sulfur atom (S) Are cyclic groups that form part of the ring skeleton of the cyclic group. The ring containing —SO ₂ — in the ring skeleton is counted as the first ring, and when it is only the ring, it is a monocyclic group, and when it has another ring structure, it is a polycyclic group regardless of the structure. Called. The —SO ₂ — containing cyclic group may be monocyclic or polycyclic.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton A cyclic group containing a sultone ring to be formed is preferable.
The —SO ₂ — containing cyclic group preferably has 3 to 30 carbon atoms, more preferably 4 to 20 carbon atoms, still more preferably 4 to 15 carbon atoms, and particularly preferably 4 to 12 carbon atoms. preferable. However, the carbon number is the number of carbon atoms constituting the ring skeleton, and does not include the carbon number in the substituent.
The —SO ₂ — containing cyclic group may be an —SO ₂ — containing aliphatic cyclic group or an —SO ₂ — containing aromatic cyclic group. Preferably -SO ₂ - containing aliphatic cyclic group.
The —SO ₂ -containing aliphatic cyclic group includes at least a hydrogen atom from an aliphatic hydrocarbon ring in which a part of carbon atoms constituting the ring skeleton is substituted with —SO ₂ — or —O—SO ₂ —. One group is excluded. More specifically, a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which —CH ₂ — constituting the ring skeleton is substituted with —SO ₂ —, —CH ₂ — constituting the ring And a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which CH ₂ — is substituted with —O—SO ₂ —.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms are removed from a monocycloalkane having 3 to 6 carbon atoms. Examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane. , Tricyclodecane, tetracyclododecane and the like.

The —SO ₂ — containing cyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ″, —OC (═O) R ″, a hydroxyalkyl group, a cyano group, and the like. Is mentioned.
The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the group couple | bonded with the oxygen atom (-O-) to the alkyl group quoted as the alkyl group as the said substituent is mentioned.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group for the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
Examples of the halogenated alkyl group as the substituent include a group in which part or all of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent are substituted with the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.
R ″ in —COOR ″ and —OC (═O) R ″ is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Alternatively, one or more hydrogen atoms are removed from a polycycloalkane such as a monocycloalkane, bicycloalkane, tricycloalkane, or tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group. More specifically, one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Group.
The hydroxyalkyl group as the substituent is preferably one having 1 to 6 carbon atoms. Specifically, at least one of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent is substituted with a hydroxyl group. Group.
More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by the following general formulas (3-1) to (3-4).

［式中、Ａ’は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり、ｚは０〜２の整数であり、Ｒ^２７はアルキル基、アルコキシ基、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり、Ｒ”は水素原子またはアルキル基である。］

[In the formula, A ′ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, z is an integer of 0 to 2, and R ²⁷ is an alkyl group. , An alkoxy group, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group, and R ″ is a hydrogen atom or an alkyl group.]

In the general formulas (3-1) to (3-4), A ′ represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (—O—) or a sulfur atom (—S—), An oxygen atom or a sulfur atom.
The alkylene group having 1 to 5 carbon atoms in A ′ is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
A ′ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
z may be any of 0 to 2, and is most preferably 0.
When z is 2, the plurality of R ²⁷ may be the same or different.
As the alkyl group, alkoxy group, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in R ²⁷ , the —SO ₂ — containing cyclic group has the above-mentioned, respectively. And the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, and hydroxyalkyl groups as those which may be substituted.
Below, the specific cyclic group represented by the said general formula (3-1)-(3-4) is illustrated. In the formula, “Ac” represents an acetyl group.

Among the above, the —SO ₂ -containing cyclic group is preferably a group represented by the general formula (3-1), and the chemical formulas (3-1-1), (3-1-18), ( It is more preferable to use at least one selected from the group consisting of groups represented by any of 3-3-1) and (3-4-1), and represented by the chemical formula (3-1-1). Are most preferred.

More specifically, examples of the structural unit (a2 ^S ) include structural units represented by general formula (a2-0) shown below.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒ^２８は−ＳＯ_２−含有環式基であり、Ｒ^２９は単結合または２価の連結基である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ²⁸ represents a —SO ₂ — containing cyclic group, and R ²⁹ represents a single bond. Or it is a bivalent coupling group. ]

In formula (a2-0), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group. Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like.
Examples of the halogenated alkyl group having 1 to 5 carbon atoms in R include groups in which part or all of the hydrogen atoms in the above-mentioned “alkyl group having 1 to 5 carbon atoms in R” are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
Especially, it is preferable that R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 fluorinated alkyl group, and it is a hydrogen atom or a methyl group from industrial availability. It is particularly preferred.

R ²⁸ is the same as the —SO ₂ — containing cyclic group mentioned above.
R ²⁹ may be a single bond or a divalent linking group. Since it is excellent in the effect of this invention, it is preferable that it is a bivalent coupling group.

As the divalent linking group for R ^29, but are not limited to, divalent hydrocarbon group which may have a substituent group, and a divalent linking group containing a hetero atom as preferred.
The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with a substituent (a group or atom other than a hydrogen atom).
The hydrocarbon group for R ²⁹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.
The aliphatic hydrocarbon group as the divalent hydrocarbon group for R ²⁹ may be saturated or unsaturated, and is usually preferably saturated.
More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, more preferably 1 to 4, and most preferably 1 to 3.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those described above.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
The alicyclic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group as the divalent hydrocarbon group for R ²⁹ preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, and 6 to 6 carbon atoms. 15 is particularly preferable, and 6 to 10 is most preferable. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; some of the carbon atoms constituting the aromatic hydrocarbon ring are heterogeneous. Aromatic heterocycles substituted with atoms; and the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) ) In which one of the hydrogen atoms is substituted with an alkylene group (for example, arylalkyl such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) Group in which one hydrogen atom is further removed from the aryl group in the group); and the like. The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.
The aromatic hydrocarbon group may or may not have a substituent. For example, a hydrogen atom bonded to the aromatic hydrocarbon ring of the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The hetero atom in the “divalent linking group containing a hetero atom” of R ²⁹ is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
As the divalent linking group containing a hetero atom, —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (= O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, —S (═O) _{2 -O -, - NH-C} (= O) -, = N-, the formula ^{-Y 21 -O-Y 22 -,} - [Y 21 -C (= O) -O] m '-Y 22 - Or a group represented by —Y ²¹ —O—C (═O) —Y ²² —, wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group optionally having a substituent. O is an oxygen atom, and m ′ is an integer of 0 to 3. ] Etc. are mentioned.
When Y ² is —NH—, H may be substituted with a substituent such as an alkyl group or an aryl group (aromatic group).
Formula ^{-Y 21 -O-Y 22 -,} - [Y 21 -C (= O) -O] m '-Y 22 - or ^{-Y 21 -O-C (= O} ) -Y 22 - ^{In, Y 21} And Y ²² are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same groups as those described above as the “divalent hydrocarbon group which may have a substituent” for Y ² .
Y ²¹ is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. preferable.
Y ²² is preferably a linear or branched aliphatic hydrocarbon group, and more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² —, m ′ is an integer of 0 to 3, preferably an integer of 0 to 2, Or 1 is more preferable, and 1 is particularly preferable. That is, the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — is represented by the formula —Y ²¹ —C (═O) —O—Y ²² —. The group is particularly preferred. Among these, a group represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} — is preferable. In the formula, a ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1.
Examples of the divalent linking group containing a hetero atom, a linear group containing an oxygen atom as a hetero atom, for example, a group containing an ether bond or an ester bond, are preferred, the formula -Y 21 ^-O-Y 22 ^-, A group represented by — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — or —Y ²¹ —O—C (═O) —Y ²² — is more preferable.

Among the above, the divalent linking group for R ²⁹ is particularly a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom. preferable. Among these, those containing an alkylene group or an ester bond (—C (═O) —O—) are preferable.
As the divalent linking group containing an ester bond, in particular, the general formula: —R ³⁰ —C (═O) —O— [wherein R ³⁰ is a divalent linking group. ] Is preferable. That is, the structural unit (a2 ^S ) is preferably a structural unit represented by the following general formula (a2-0-1).

［式中、ＲおよびＲ^２８はそれぞれ前記と同様であり、Ｒ^３０は２価の連結基である。］

[Wherein, R and R ²⁸ are the same as defined above, and R ³⁰ represents a divalent linking group. ]

R ³⁰ is not particularly limited, and examples thereof include the same divalent linking groups as R ²⁹ in formula (a2-0).
As the divalent linking group for R ^30, a linear or branched alkylene group, an aliphatic hydrocarbon group containing a ring in the structure, or a divalent linking group containing a hetero atom is preferable. Alternatively, a branched alkylene group or a divalent linking group containing an oxygen atom as a hetero atom is preferable.
As the linear alkylene group, a methylene group or an ethylene group is preferable, and a methylene group is particularly preferable.
As the branched alkylene group, an alkylmethylene group or an alkylethylene group is preferable, and —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — or —C (CH ₃ ) ₂ CH ₂ — is particularly preferable.
The divalent linking group containing an oxygen atom is preferably a divalent linking group containing an ether bond or an ester bond, and the above-described —Y ²¹ —O—Y ²² —, — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — or —Y ²¹ —O—C (═O) —Y ²² — is more preferable. Y ²¹ , Y ²² and m ′ are the same as described above.

As the structural unit (a2 ^S ), a structural unit represented by general formula (a2-0-11) or (a2-0-12) shown below is particularly desirable, and represented by formula (a2-0-12). A structural unit is more preferable.

［式中、Ｒ、Ａ’、Ｒ^２７、ｚおよびＲ^３０はそれぞれ前記と同じである。］

[Wherein, R, A ′, R ²⁷ , z and R ³⁰ are the same as defined above. ]

In formula (a2-0-11), A ′ is preferably a methylene group, an oxygen atom (—O—) or a sulfur atom (—S—).
As the structural unit represented by the formula (a2-0-12), a structural unit represented by the following general formula (a2-0-12a) or (a2-0-12b) is particularly preferable.

［式中、ＲおよびＡ’はそれぞれ前記と同じであり、ｃ〜ｅはそれぞれ独立に１〜３の整数である。］

[Wherein, R and A ′ are the same as defined above, and c to e are each independently an integer of 1 to 3.] ]

-Structural unit (a2 ^L ):
The structural unit (a2 ^L ) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and includes a lactone-containing cyclic group. is there.
Here, the lactone-containing cyclic group refers to a cyclic group containing a ring (lactone ring) containing —O—C (═O) — in the ring skeleton. The lactone ring is counted as the first ring. When only the lactone ring is present, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone cyclic group in the structural unit (a2 ^L ) is not particularly limited, and any one can be used. Specifically, the lactone-containing monocyclic group is a group obtained by removing one hydrogen atom from a 4- to 6-membered ring lactone, such as a group obtained by removing one hydrogen atom from β-propionolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed and a group in which one hydrogen atom has been removed from δ-valerolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
Examples of the structural unit (a2 ^L ) include those obtained by substituting R ²⁸ in the general formula (a2-0) with a lactone-containing cyclic group, and more specifically, the following general formula (a2- The structural unit represented by 1)-(a2-7) is mentioned.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり；Ｒ’はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり、Ｒ”は水素原子またはアルキル基であり；Ｒ^２９は単結合または２価の連結基であり、ｓ”は０〜２の整数であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり；ｍは０または１である。］

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; R ′ is independently a hydrogen atom, an alkyl group, an alkoxy group, or a halogenated alkyl group; , Hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group, R ″ is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group; s ″ is an integer of 0 to 2; A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom; m is 0 or 1. ]

R in the general formulas (a2-1) to (a2-7) is the same as described above.
As the alkyl group, alkoxy group, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in R ′, the —SO ₂ — containing cyclic group has the above-mentioned, respectively. And the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, and hydroxyalkyl groups as those which may be substituted. The same applies to R ″.
R ′ is preferably a hydrogen atom in view of industrial availability.
Examples of A ″ include the same as A ′ in the general formula (3-1). A ″ represents an alkylene group having 1 to 5 carbon atoms, an oxygen atom (—O—) or a sulfur atom (— S-) is preferable, and an alkylene group having 1 to 5 carbon atoms or -O- is more preferable. The alkylene group having 1 to 5 carbon atoms is more preferably a methylene group or dimethylmethylene group, and most preferably a methylene group.
R ²⁹ is the same as ^{R 29} in the aforementioned general formula (a2-0).
In formula (a2-1), s ″ is preferably 1 to 2.
Specific examples of the structural units represented by the general formulas (a2-1) to (a2-7) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (a2 ^L ) is preferably at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-7). Use of a monocyclic lactone represented by the formula (a2-1) is preferable because roughness such as LWR is improved.
On the other hand, EL and the like can also be improved by using polycyclic lactones represented by formulas (a2-1) to (a2-7).
Among them, the formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-7), (a2-2-12), (a2-2-2-) 14), (a2-3-1), at least one selected from the group consisting of structural units represented by (a2-3-5) is preferred.

Structural Unit ^(a2 C):
The structural unit (a2 ^C ) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and includes a carbonate-containing cyclic group. is there.
Here, the carbonate-containing cyclic group refers to a cyclic group containing one ring (cyclic carbonate) containing a —O—C (═O) —O— structure. The cyclic carbonate ring is counted as the first ring. When only the cyclic carbonate ring is used, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
As the structural unit (a2 ^C ), structural units represented by general formula (a23-1) shown below can be given.

［式中、Ｒ、Ｒ’、Ｒ^２９、Ａ”はそれぞれ前記同様であり、ｑ”は１〜３の整数である。］

[Wherein, R, R ′, R ²⁹ and A ″ are the same as defined above, and q ″ is an integer of 1 to 3. ]

R, R ′, R ²⁹ and A ″ in the formula (a23-1) are the same as those in the general formulas (a2-1) to (a2-7).
q ″ is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.
Specific examples of the structural units represented by the general formulas (a23-1) to (a23-3) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (a2) contained in the component (A0) may be one type or two or more types. For example, as the structural unit (a2), only the structural unit (a2 ^S ) may be used, only the structural unit (a2 ^L ) may be used, or only the structural unit (a2 ^C ) may be used. May be used in combination. When used in combination, the structural unit (a2 ^L ) and the structural unit (a2 ^S ) are preferably used in combination. The structural unit (a2 ^S ), the structural unit (a2 ^L ), or the structural unit (a2 ^C) ), One type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a2) is preferably 1 to 80 mol%, more preferably 10 to 70 mol%, based on the total of all structural units constituting the component (A0). More preferably, it is 65 mol%, and 10 to 60 mol% is especially preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units, such as various kinds of DOF, CDU, etc. The lithography characteristics and pattern shape of the film are improved.

In the resist composition of the present invention, in addition to the structural unit (a2), the component (A0) particularly has a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid. (In other words, the component (A0) is preferably the component (A1)).
In addition to the structural unit (a2), or the component (A0), in addition to the structural units (a1) and (a2), the structural unit (a3) containing the polar group (provided that the structural unit (A1) and the structural unit (a2) may be excluded).

(Structural unit (a1))
In addition to the structural unit (a2), the component (A0) particularly preferably has a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid.
“Acid-decomposable group” is an acid-decomposable group in which at least a part of the bond in the structure of the acid-decomposable group can be cleaved by the action of an acid generated by exposure (such as an acid generated from the component (B) described later). It is a group having properties.
Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (—SO ₃ H), and the like. Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include a group in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).
An “acid-dissociable group” is a group having an acid-dissociable property capable of cleaving at least a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid generated by exposure. is there. The acid-dissociable group constituting the acid-decomposable group must be a group having a lower polarity than the polar group generated by dissociation of the acid-dissociable group. Is dissociated, a polar group having a polarity higher than that of the acid dissociable group is generated to increase the polarity. As a result, the polarity of the entire component (A0) increases. As the polarity increases, the solubility in the developer changes relatively. When the developer is an alkaline developer, the solubility increases. On the other hand, the developer contains an organic solvent (organic type). In the case of a developer, the solubility decreases.

The acid-dissociable group is not particularly limited, and those that have been proposed as acid-dissociable groups for base resins for chemically amplified resists can be used. In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like, an acetal type acid dissociable group such as an alkoxyalkyl group, and the like are widely known.
Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (═O The structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of) -O-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom to form a carboxy group.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable group” for convenience.

Examples of the tertiary alkyl ester type acid dissociable group include an aliphatic branched acid dissociable group and an acid dissociable group containing an aliphatic cyclic group.
Here, “aliphatic branched” means having a branched structure having no aromaticity. The structure of the “aliphatic branched acid dissociable group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
Examples of the aliphatic branched acid dissociable group include a group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ). ^Wherein, R 71 ^{to R 73} each independently represents a linear alkyl group of 1 to 5 carbon atoms. The group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ) preferably has 4 to 8 carbon atoms, specifically a tert-butyl group or a 2-methyl-2-butyl group. , 2-methyl-2-pentyl group, 3-methyl-3-pentyl group and the like. A tert-butyl group is particularly preferable.

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The aliphatic cyclic group in the “acid-dissociable group containing an aliphatic cyclic group” may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like. Is mentioned.
The basic ring structure excluding the substituent of the aliphatic cyclic group is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The hydrocarbon group may be either saturated or unsaturated, but is usually preferably saturated.
The aliphatic cyclic group may be monocyclic or polycyclic.
As the aliphatic cyclic group, those having 3 to 30 carbon atoms are preferable, those having 5 to 30 are more preferable, 5 to 20 are more preferable, 6 to 15 are particularly preferable, and 6 to 12 is most preferable. . Examples of the aliphatic cyclic group include one or more monocycloalkanes which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group. A group in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, tricycloalkane, or tetracycloalkane; More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. An alicyclic hydrocarbon group such as a group excluding a hydrogen atom is exemplified. Moreover, a part of carbon atoms constituting the ring of these alicyclic hydrocarbon groups may be substituted with an ether group (—O—).

Examples of the acid dissociable group containing an aliphatic cyclic group include:
(I) On a ring skeleton of a monovalent aliphatic cyclic group, a substituent (on a carbon atom bonded to an atom adjacent to the acid dissociable group (for example, —O— in —C (═O) —O—)) A group in which a tertiary carbon atom is formed by bonding to an atom or group other than a hydrogen atom (hereinafter sometimes referred to as a “group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group”);
(Ii) a group having a monovalent aliphatic cyclic group and a branched alkylene having a tertiary carbon atom bonded thereto.
In the group (i), the substituent bonded to the carbon atom bonded to the atom adjacent to the acid dissociable group on the ring skeleton of the aliphatic cyclic group may have, for example, a substituent. An alkyl group is mentioned. Examples of the alkyl group include those similar to R ¹⁴ in formulas (1-1) to (1-9) described later.
Specific examples of the group (i) include groups represented by the following general formulas (1-1) to (1-9).
Specific examples of the group (ii) include groups represented by the following general formulas (2-1) to (2-6).

［式中、Ｒ^１４は置換基を有していていもよいアルキル基であり、ｇは０〜８の整数である。］

[Wherein, R ¹⁴ represents an alkyl group which may have a substituent, and g represents an integer of 0 to 8. ]

［式中、Ｒ^１５およびＲ^１６は、それぞれ独立してアルキル基である。］

[Wherein, R ¹⁵ and R ¹⁶ each independently represents an alkyl group. ]

In formulas (1-1) to (1-9), the alkyl group of R ¹⁴ may be linear, branched or cyclic, and is preferably linear or branched.

The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and still more preferably 1 or 2. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group and the like, and isopropyl group is most preferable.
The linear or branched alkyl group may have a substituent. Examples of the substituent include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), a cyano group, and a carboxy group.

The cyclic alkyl group preferably has 3 to 10 carbon atoms, and more preferably 5 to 8 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The cyclic alkyl group may have a substituent. Specifically, some or all of the hydrogen atoms constituting the alkyl group may be substituted with alkoxy groups, halogen atoms, halogenated alkyl groups, hydroxyl groups, oxygen atoms (═O), cyano groups, carboxy groups, or the like. In addition, some or all of the carbon atoms constituting the alkyl group may be substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom.
g is preferably an integer of 0 to 3, more preferably an integer of 1 to 3, and still more preferably 1 or 2.

In formulas (2-1) to (2-6), examples of the alkyl group for R ^{15 to} R ¹⁶ include the same alkyl groups as those described above for R ¹⁴ .
In the formulas (1-1) to (1-9) and (2-1) to (2-6), a part of the carbon atoms constituting the ring is substituted with an etheric oxygen atom (—O—). May be.
In formulas (1-1) to (1-9) and (2-1) to (2-6), a hydrogen atom bonded to a carbon atom constituting the ring may be substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, and a fluorinated alkyl group.

The “acetal-type acid dissociable group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an OH-containing polar group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, this acid acts to break the bond between the acetal type acid dissociable group and the oxygen atom to which the acetal type acid dissociable group is bonded. OH-containing polar groups are formed.
Examples of the acetal type acid dissociable group include a group represented by the following general formula (p1).

［式中、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５のアルキル基を表し、ｎは０〜３の整数を表し、Ｙは炭素数１〜５のアルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ ′ and R ² ′ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 3, and Y represents an alkyl group having 1 to 5 carbon atoms. Or represents an aliphatic cyclic group. ]

In formula (p1), n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
In formula (p1), R ^{1 ′} and R ^{2 ′} are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms of R ^{1 ′} and R ^{2 ′} include the same as the alkyl group having 1 to 5 carbon atoms of R, and a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable. preferable.
In the present invention, at least one of R ^{1 ′} and R ^{2 ′} is preferably a hydrogen atom, preferably a combination of a hydrogen atom and a methyl group, or a combination of hydrogen atoms. That is, the acid dissociable group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同じである。］

[Wherein R ¹ ′, n and Y are the same as described above. ]

Examples of the alkyl group having 1 to 5 carbon atoms of Y include the same as the alkyl group having 1 to 5 carbon atoms of R.
The aliphatic cyclic group for Y can be appropriately selected and used from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. Examples thereof are the same as the aliphatic cyclic groups mentioned in “Acid-dissociable groups containing formula groups”.

  Examples of the acetal type acid dissociable group also include a group represented by the following general formula (p2).

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状若しくは分岐鎖状のアルキル基または水素原子であり；Ｒ^１９は直鎖状、分岐鎖状若しくは環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状若しくは分岐鎖状のアルキレン基であって、Ｒ^１７とＲ^１９とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represents a linear or branched alkyl group or a hydrogen atom; and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ may each independently be a linear or branched alkylene group, and R ¹⁷ and R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group.
In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. And the like, in which a hydrogen atom is removed. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the formula (p2), R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and R ¹⁹ and R ¹⁷ And may be combined.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  In the resist composition of the present invention, the structural unit (a1) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, The structural unit (a11) containing an acid-decomposable group whose polarity is increased by the action of: at least part of the hydrogen atoms in the hydroxyl group of the structural unit derived from hydroxystyrene or a hydroxystyrene derivative Protected structural unit (a12), at least part of hydrogen atoms in —C (═O) —OH of the structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative are protected by a substituent containing an acid-decomposable group And the structural unit (a13).

Here, in the present specification and claims, the “structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid ester” is a compound in which the hydrogen atom at the carboxy group terminal of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
In the acrylate ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent that replaces the hydrogen atom bonded to the α-position carbon atom is an atom or group other than a hydrogen atom, such as an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or carbon. Examples thereof include hydroxyalkyl groups of 1 to 5. The α-position carbon atom of the acrylate ester is a carbon atom to which a carbonyl group is bonded unless otherwise specified.
Hereinafter, an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylate ester. Further, the acrylate ester and the α-substituted acrylate ester may be collectively referred to as “(α-substituted) acrylate ester”.
In the α-substituted acrylate ester, the alkyl group as a substituent at the α-position is preferably a linear or branched alkyl group, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, n- Examples thereof include a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group.
Specific examples of the halogenated alkyl group as the substituent at the α-position include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α-position” are substituted with a halogen atom. It is done. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
Specific examples of the hydroxyalkyl group as the substituent at the α-position include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α-position” are substituted with a hydroxy group. .
Bonded to the α-position of the α-substituted acrylate ester is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. An alkyl group or a fluorinated alkyl group having 1 to 5 carbon atoms is more preferred, and a hydrogen atom or a methyl group is most preferred from the viewpoint of industrial availability.

“A structural unit derived from hydroxystyrene or a hydroxystyrene derivative” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene or a hydroxystyrene derivative.
“Hydroxystyrene derivative” is a concept including those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
The “structural unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative” means a structural unit configured by cleavage of an ethylenic double bond of vinyl benzoic acid or a vinyl benzoic acid derivative.
The “vinyl benzoic acid derivative” is a concept including a compound in which the hydrogen atom at the α-position of vinyl benzoic acid is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
Hereinafter, the structural unit (a11), the structural unit (a12), and the structural unit (a13) will be described.

(Structural unit (a11))
Specific examples of the structural unit (a11) include structural units represented by general formula (a11-0-1) shown below, structural units represented by general formula (a11-0-2) shown below, and the like. .

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり；Ｘ^１は酸解離性基であり；Ｙ^２は２価の連結基であり；Ｘ^２は酸解離性基である。］

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; X ¹ is an acid dissociable group; Y ² is a divalent linking group. Yes; X ² is an acid-dissociable group. ]

In general formula (a11-0-1), R is the same as R in formula (a2-0).
X ¹ is not particularly limited as long as it is an acid dissociable group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable groups, acetal type acid dissociable groups, and the like. An ester type acid dissociable group is preferred.
In general formula (a11-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a11-0-1).

Examples of the divalent linking group of Y ^2, but are not limited to, the formula (a2-0) divalent divalent which may have a substituent mentioned in linking group hydrocarbon of R ²⁹ in the Preferred examples include a group and a divalent linking group containing a hetero atom.
Among these, the divalent linking group for Y ² is particularly preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom. Among these, a linear or branched alkylene group or a divalent linking group containing a hetero atom is preferable.

  More specifically, examples of the structural unit (a11) include structural units represented by general formulas (a1-1) to (a1-4) shown below.

［式中、Ｒ、Ｒ^１’、Ｒ^２’、ｎ、ＹおよびＹ^２はそれぞれ前記と同じであり、Ｘ’は第３級アルキルエステル型酸解離性基を表す。］’

[Wherein, R, R ¹ ′, R ² ′, n, Y and Y ² are the same as defined above, and X ′ represents a tertiary alkyl ester-type acid dissociable group. ] '

In the formula, X ′ is the same as the tertiary alkyl ester-type acid dissociable group.
^{R 1 ', R 2',} n, as the Y, respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable group" described above ^{(p1) ', R 2'} , n, similarly to the Y Can be mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in the above general formula (a11-0-2).
Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.
In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

In the present invention, the structural unit (a11) is represented by the following general formulas (a11-0-11) to (a11-0-15) and the following general formula (a11-0-2). It is preferable to have at least one selected from the group consisting of structural units.
Especially, it is more preferable to have at least one selected from the group consisting of structural units represented by the following general formulas (a11-0-11) to (a11-0-15), and has a monocyclic protecting group It is more preferable to have at least one of structural units represented by the following general formulas (a11-0-11) and (a11-0-14).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒ^２１はアルキル基であり；Ｒ^２２は、当該Ｒ^２２が結合した炭素原子と共に脂肪族単環式基を形成する基であり；Ｒ^２３は分岐鎖状のアルキル基であり；Ｒ^２４は、当該Ｒ^２４が結合した炭素原子と共に脂肪族多環式基を形成する基であり；Ｒ^２５は炭素数１〜５の直鎖状のアルキル基である。Ｒ^１５およびＲ^１６は、それぞれ独立してアルキル基である。Ｙ^２は２価の連結基であり、Ｘ^２は酸解離性基である。］

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ²¹ is an alkyl group; R ²² is a carbon to which R ²² is bonded. A group that forms an aliphatic monocyclic group together with an atom; R ²³ is a branched alkyl group; and R ²⁴ is a group that forms an aliphatic polycyclic group together with the carbon atom to which R ²⁴ is bonded. R ²⁵ is a linear alkyl group having 1 to 5 carbon atoms. R ¹⁵ and R ¹⁶ are each independently an alkyl group. Y ² is a divalent linking group, and X ² is an acid dissociable group. ]

In each formula, the description of R, Y ² and X ² is the same as described above.
In formula (a11-0-11), examples of the alkyl group for R ²¹ include the same alkyl groups as those described above for R ¹⁴ in formulas (1-1) to (1-9). Group, isopropyl group, or cyclic alkyl group (preferably polycyclic group) is preferable.
R ²² is, the aliphatic monocyclic group formed together with the carbon atom to which R ²² is bonded, the same aliphatic cyclic groups as those in the aforementioned tertiary alkyl ester-type acid dissociable groups, a monocyclic group The thing similar to what is is mentioned. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably a 3- to 11-membered ring, more preferably a 3- to 8-membered ring, further preferably a 4- to 6-membered ring, and particularly preferably a 5- or 6-membered ring.
In the monocycloalkane, a part of carbon atoms constituting the ring may or may not be substituted with an ether group (—O—).
Moreover, this monocycloalkane may have a C1-C5 alkyl group, a fluorine atom, or a C1-C5 fluorinated alkyl group as a substituent.
Examples of R ²² constituting such an aliphatic monocyclic group include a linear alkylene group in which an ether group (—O—) may be interposed between carbon atoms.

Specific examples of the structural unit represented by the formula (a11-0-11) include the formulas (a1-1-16) to (a1-1-23), (a1-1-27), and (a1-1 -31) and structural units represented by (a1-1-37). Among these, the formulas (a1-1-16) to (a1-1-17), (a1-1-20) to (a1-1-23), (a1-1-27), (a1-1-1- 31), a structural unit represented by the following (a11-1-02) including the structural unit represented by (a1-1-33), (a1-1-33), (a1-1-37) preferable. Moreover, the structural unit represented by the following (a11-1-02 ′) is also preferable.
In each formula, h is an integer of 1 to 4, and 1 or 2 is preferable.

［式中、Ｒ、Ｒ^２１はそれぞれ前記と同じであり、ｈは１〜４の整数である。］

[Wherein, R and R ²¹ are the same as defined above, and h is an integer of 1 to 4, respectively. ]

Wherein ^(A11-0-12), as the branched alkyl group for ^{R 23,} alkyl of the formula (1-1) to (1-9) branched chain mentioned by an alkyl group ^{R 14} in Examples thereof are the same as those described above, and an isopropyl group is most preferable.
R ²⁴ is, the aliphatic polycyclic group formed together with the carbon atom to which R ²⁴ is bonded, the same aliphatic cyclic groups as those in the aforementioned tertiary alkyl ester-type acid dissociable group, polycyclic group The thing similar to what is is mentioned.
Specific examples of the structural unit represented by the formula (a11-0-12) include those represented by the formulas (a1-1-26) and (a1-1-28) to (a1-1-30). Units are listed.
The constitutional unit represented by formula ^{(a11-0-12), R 24} is preferably the aliphatic polycyclic group which forms together with the carbon atom to which ^{R 24} is bonded is a 2-adamantyl group, especially The structural unit represented by the formula (a1-1-26) is preferable.

In formula (a11-0-13), R and R ²⁴ are the same as defined above.
Examples of the linear alkyl group for R ²⁵ include the same linear alkyl groups as those described above for the alkyl group for R ^{14 in} the formulas (1-1) to (1-9), and methyl Most preferred are groups or ethyl groups.
Specific examples of the structural unit represented by the formula (a11-0-13) include formulas (a1-1-1) to (a1-1-2) exemplified as specific examples of the general formula (a1-1). ), Structural units represented by (a1-1-7) to (a1-1-15).
The constitutional unit represented by formula ^{(a11-0-13), R 24} is preferably the aliphatic polycyclic group which forms together with the carbon atom to which ^{R 24} is bonded is a 2-adamantyl group, especially The structural unit represented by the formula (a1-1-1) or (a1-1-2) is preferable. Further, R ²⁴ is also preferably the aliphatic polycyclic group which forms together with the carbon atom to which R ²⁴ is bonded is a "group obtained by removing one or more hydrogen atoms from tetracyclododecane", the formula (a1 The structural unit represented by (-1-8), (a1-1-9) or (a1-1-30) is also preferable.

In formula (a11-0-14), R and R ²² are the same as defined above. R ¹⁵ and ^{R 16} are the same as ^{R 15} and ^{R 16} in each of the general formulas (2-1) to (2-6).
Specific examples of the structural unit represented by the formula (a11-0-14) include the formulas (a1-1-35) and (a1-1-36) exemplified as specific examples of the general formula (a1-1). ).

In formula (a11-0-15), R and R ²⁴ are the same as defined above. R ¹⁵ and ^{R 16} are the same as ^{R 15} and ^{R 16} in each of the general formulas (2-1) to (2-6).
Specific examples of the structural unit represented by the formula (a11-0-15) include formulas (a1-1-4) to (a1-1-6) exemplified as specific examples of the general formula (a1-1). ) And (a1-1-34).

Formula (a11-0-2) is the same as above.
Preferred examples of the structural unit include a structural unit represented by the following general formula (a1-3-01); a structural unit represented by the following general formula (a1-3-02); 3-03) and the like.

［式中、Ｒは前記と同じであり、Ｒ^１３は水素原子またはメチル基であり、Ｒ^１４はアルキル基であり、ｅは１〜１０の整数であり、ｎ’は０〜３の整数である。］

[Wherein, R is the same as above, R ¹³ is a hydrogen atom or a methyl group, R ¹⁴ is an alkyl group, e is an integer of 1 to 10, and n ′ is an integer of 0 to 3] is there. ]

［式中、Ｒは前記と同じであり、Ｙ^２’およびＹ^２”はそれぞれ独立して２価の連結基であり、Ｘ’は酸解離性基であり、ｗは０〜３の整数である。］

[Wherein, R is the same as defined above, Y ² ′ and Y ² ″ are each independently a divalent linking group, X ′ is an acid-dissociable group, and w is an integer of 0 to 3] is there.]

In formulas (a1-3-01) to (a1-3-02), R ¹³ is preferably a hydrogen atom.
R ¹⁴ is the same as ^{R 14} in the formula (1-1) to (1-9).
e is preferably an integer of 1 to 8, more preferably an integer of 1 to 5, and most preferably 1 or 2.
n ′ is preferably 1 or 2, and most preferably 2.
Specific examples of the structural unit represented by the formula (a1-3-01) include structural units represented by the formulas (a1-3-25) to (a1-3-26).
Specific examples of the structural unit represented by the formula (a1-3-02) include structural units represented by the formulas (a1-3-27) to (a1-3-28).

In formula (a1-3-03), examples of the divalent linking group for Y ² ′ and Y ² ″ include the same groups as those described above for Y ² in formula (a1-3).
Y ² ′ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and even more preferably a linear alkylene group. Among these, a linear alkylene group having 1 to 5 carbon atoms is preferable, and a methylene group and an ethylene group are most preferable.
Y ² ″ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and still more preferably a linear alkylene group. A linear alkylene group of 1 to 5 is preferable, and a methylene group and an ethylene group are most preferable.
Examples of the acid dissociable group in X ′ include the same groups as described above, and are preferably tertiary alkyl ester-type acid dissociable groups. In addition, a group in which a substituent is bonded to a carbon atom bonded to an atom adjacent to the acid dissociable group to form a tertiary carbon atom is more preferable. Preferred are the groups
w is an integer of 0 to 3, and w is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.
As the structural unit represented by the formula (a1-3-03), a structural unit represented by the following general formula (a1-3-03-1) or (a1-3-03-2) is preferable. The structural unit represented by the formula (a1-3-03-1) is preferable.

［式中、ＲおよびＲ^１４はそれぞれ前記と同じであり、ａ’は１〜１０の整数であり、ｂ’は１〜１０の整数であり、ｔは０〜３の整数である。］

[Wherein, R and R ¹⁴ are the same as defined above, a ′ is an integer of 1 to 10, b ′ is an integer of 1 to 10, and t is an integer of 0 to 3, respectively. ]

In formulas (a1-3-03-1) to (a1-3-03-2), a ′ is the same as described above, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, or 1 or 2 is particularly preferred.
b ′ is the same as described above, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, and particularly preferably 1 or 2.
t is preferably an integer of 1 to 3, and 1 or 2 is particularly preferable.
Specific examples of the structural unit represented by formula (a1-3-03-1) or (a1-3-03-2) include those represented by formulas (a1-3-29) to (a1-3-32). The structural unit represented is mentioned.

(Structural unit (a12), Structural unit (a13))
In the present specification, the structural unit (a12) is a structural unit in which at least a part of the hydrogen atoms in the hydroxyl group of the structural unit derived from hydroxystyrene or a hydroxystyrene derivative is protected by a substituent containing an acid-decomposable group. .
In addition, the structural unit (a13) is protected by a substituent in which at least part of the hydrogen atoms in —C (═O) —OH of the structural unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative contains an acid-decomposable group. Unit.
In the structural unit (a12) and the structural unit (a13), examples of the substituent containing an acid-decomposable group include the tertiary alkyl ester type acid dissociable group and the acetal type acid dissociable group described in the structural unit (a11). Is preferable.

  Preferred examples of the structural unit (a12) and the structural unit (a13) are represented by any of the following general formulas (a12-1) to (a12-4) and general formula (a13-1). A structural unit etc. can be illustrated.

［式（ａ１２−１）〜（ａ１２−４）、（ａ１３−１）中、Ｒは上記同様であり；Ｒ^８８はハロゲン原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり；ｑは０〜４の整数であり；Ｒ^１’は上記同様であり；ｎは０〜３の整数であり；Ｗは脂肪族環式基、芳香族環式炭化水素基又は炭素数１〜５のアルキル基であり；ｒは１〜３であり；Ｒ^４１、Ｒ^４２、Ｒ^４３はそれぞれ独立して直鎖状または分岐鎖状のアルキル基であり；Ｘ^１は酸解離性基である。］

Expression (a12-1) ~ (a12-4), (a13-1) , R represents a similar ^{above; R 88} is a halogen atom, an alkyl group, or a halogen of 1 to 5 carbon atoms of 1 to 5 carbon atoms Q is an integer of 0 to 4; R ¹ ′ is the same as above; n is an integer of 0 to 3; W is an aliphatic cyclic group or an aromatic cyclic hydrocarbon group Or an alkyl group having 1 to 5 carbon atoms; r is 1 to 3; R ⁴¹ , R ⁴² and R ⁴³ are each independently a linear or branched alkyl group; and X ¹ is an acid. It is a dissociable group. ]

In the formulas (a12-1) to (a12-4) and (a13-1), “—O—CHR ¹ ′ —O— (CH ₂ ) _n —W”, “—O—C (O) —O”. —C (R ⁴¹ ) (R ⁴² ) (R ⁴³ ) ”,“ —O—C (O) —O—X ¹ ”,“ —O— (CH ₂ ) _r —C (O) —O—X ¹ ”And“ —C (O) —O—X ¹ ”may be bonded to the phenyl group at any of the o-position, m-position and p-position of the phenyl group, and the effect of the present invention is good. For some reason, the p-position is most preferred.

R ⁸⁸ is a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
Examples of the halogen atom for R ⁸⁸ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferred.
Examples of the alkyl group having 1 to 5 carbon atoms and the halogenated alkyl group having 1 to 5 carbon atoms of R ⁸⁸ are the same as the alkyl group having 1 to 5 carbon atoms and the halogenated alkyl group having 1 to 5 carbon atoms. Is mentioned.
The substitution position of R ⁸⁸ may be any of the o-position, m-position and p-position when q is 1.
When q is 2, arbitrary substitution positions can be combined.
However, 1 ≦ p + q ≦ 5.

q is an integer of 0 to 4, preferably 0 or 1, and more preferably 0 industrially.
n represents an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
The aliphatic cyclic group in W is a monovalent aliphatic cyclic group. The aliphatic cyclic group can be appropriately selected from, for example, those proposed in a number of conventional ArF resists. Specific examples of the aliphatic cyclic group include an aliphatic monocyclic group having 5 to 7 carbon atoms and an aliphatic polycyclic group having 10 to 16 carbon atoms.
The aliphatic cyclic group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like. Is mentioned.
The basic ring structure excluding the substituent of the aliphatic cyclic group is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), and has an oxygen atom or the like in the ring structure. May be.
Examples of the aliphatic monocyclic group having 5 to 7 carbon atoms include groups in which one hydrogen atom has been removed from a monocycloalkane. Specifically, one hydrogen atom has been removed from cyclopentane, cyclohexane and the like. Group.
Examples of the aliphatic polycyclic group having 10 to 16 carbon atoms include groups in which one hydrogen atom has been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which one hydrogen atom has been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these, an adamantyl group, a norbornyl group, and a tetracyclododecyl group are industrially preferable, and an adamantyl group is particularly preferable.
Examples of the aromatic cyclic hydrocarbon group for W include aromatic polycyclic groups having 10 to 16 carbon atoms. Specific examples include groups in which one hydrogen atom has been removed from naphthalene, anthracene, phenanthrene, pyrene, and the like.
Specific examples include 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 1-pyrenyl group, and the like. A naphthyl group is particularly preferred industrially.
Examples of the alkyl group having 1 to 5 carbon atoms of W include the same as the alkyl group having 1 to 5 carbon atoms that may be bonded to the α-position of the hydroxystyrene, and a methyl group or an ethyl group is more preferable. Most preferred is an ethyl group.

R ^{41 to} R ⁴³ are preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms. As a specific example, R 1 to R ⁴³ has 1 to 5 carbon atoms. The same as those exemplified for the alkyl group.
Acid-dissociable group of X ¹ is the same as the acid-dissociable group of ^{X 1} in the formula (a11-0-1).
r is preferably 1 or 2, more preferably 1.

Among the structural units (a12) and (a13), the structural unit (a12) is preferable, and the structural unit represented by the general formula (a12-1) and the structure represented by the general formula (a12-4). Units are more preferred.
Preferred specific examples of the structural unit (a12) are shown below.

  As the structural unit (a12), at least one selected from the chemical formulas (a12-1-1) to (a12-1-12) is preferable, and the chemical formulas (a12-1-1) and (a12-1-2) (A12-1-5) to (a12-1-12) are most preferable.

The structural unit (a1) contained in the component (A0) may be one type or two or more types.
Among these, the structural unit (a1) is preferably a structural unit (a11) derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. .
In the component (A0), the proportion of the structural unit (a1) is preferably from 10 to 70 mol%, more preferably from 15 to 66 mol%, more preferably from 20 to 60 mol%, based on all structural units constituting the component (A0). Is more preferable, and 35-50 mol% is especially preferable.
By setting the proportion of the structural unit (a1) to the lower limit value or more, a pattern can be easily obtained when a resist composition is formed, and the lithography properties such as sensitivity, resolution, and LWR are also improved. Moreover, it becomes easy to balance with another structural unit by setting it as an upper limit or less.

・ Structural unit (a3)
The structural unit (a3) is a structural unit (a3) that does not correspond to the structural units (a0), (a1), and (a2) and includes a polar group. When the component (A0) has the structural unit (a3), the polarity of the component (A0) after exposure is further improved. The improvement in polarity contributes to an improvement in resolution and the like, particularly in the case of an alkali development process.
Examples of the polar group include —OH, —COOH, —CN, —SO ₂ NH ₂ , —CONH ₂ , and the like. Those containing —COOH also include structural units of (α-substituted) acrylic acid.
The structural unit (a3) is preferably a structural unit containing a hydrocarbon group in which a part of hydrogen atoms is substituted with a polar group. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Of these, the hydrocarbon group is more preferably an aliphatic hydrocarbon group.
Examples of the aliphatic hydrocarbon group in the hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and an aliphatic cyclic group (monocyclic group, polycyclic group). Cyclic group).
As the aliphatic cyclic group (monocyclic group, polycyclic group), for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from those proposed. The aliphatic cyclic group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. Specifically, for example, a group in which two or more hydrogen atoms have been removed from a monocycloalkane; a group in which two or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which two or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane; two or more groups from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom. The aliphatic cyclic group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, and a fluorinated alkyl group having 1 to 5 carbon atoms.

The aromatic hydrocarbon group in the hydrocarbon group is a hydrocarbon group having an aromatic ring, preferably having 5 to 30 carbon atoms, more preferably 6 to 20, still more preferably 6 to 15 and 6 Is most preferred. However, the carbon number does not include the carbon number in the substituent. The aromatic ring of the aromatic hydrocarbon group is the same as described above, and specifically includes benzene, naphthalene, anthracene, phenanthrene and the like.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two or more hydrogen atoms from the aromatic ring (arylene group); an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.) A group in which two atoms are removed; a group in which one of the hydrogen atoms in the aromatic ring (aryl group) is substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl) Group, a group obtained by further removing one hydrogen atom from an aryl group in an arylalkyl group such as a 2-naphthylmethyl group, a 1-naphthylethyl group, and a 2-naphthylethyl group. The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.
The aromatic hydrocarbon group may or may not have a substituent. For example, the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, a halogen atom, and a halogenated alkyl group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

  As the structural unit (a3), structural units represented by general formula (a3-1) shown below are preferred.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基、または炭素数１〜５のハロゲン化アルキル基である。Ｐ^０は−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−ＮＲ^０−（Ｒ^０は水素原子または炭素数１〜５のアルキル基である）または単結合である。Ｗ^０は−ＣＯＯＨ、または置換基として−ＯＨ、−ＣＯＯＨ、−ＣＮ、−ＳＯ_２ＮＨ_２及び−ＣＯＮＨ_２からなる群より選択される少なくとも一種の基を有する炭化水素基、または、−ＣＯＮＨＣＯ−Ｒ^ａ３（Ｒ^ａ３は炭化水素基）であり、任意の位置に酸素原子または硫黄原子を有していてもよい。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. P ⁰ is —C (═O) —O—, —C (═O) —NR ⁰ — (R ⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) or a single bond. W ⁰ is —COOH, a hydrocarbon group having at least one group selected from the group consisting of —OH, —COOH, —CN, —SO ₂ NH ₂ and —CONH ₂ as a substituent, or —CONHCO— R ^a3 (R ^a3 is a hydrocarbon group), which may have an oxygen atom or a sulfur atom at an arbitrary position. ]

In the formula (a3-1), R is the same as described above.
In the formula (a3-1), P ⁰ is —C (═O) —O—, —C (═O) —NR ⁰ — (R ⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ) Or a single bond. The alkyl group for R ⁰ is the same as the alkyl group for R.

In the formula (a3-1), W ⁰ is a hydrocarbon group having at least one group selected from the group consisting of —OH, —COOH, —CN, —SO ₂ NH ₂ and —CONH ₂ as a substituent. or a ^{-CONHCO-R a3 (R} a3 is a hydrocarbon group) may have an oxygen atom or a sulfur atom in any position.
The “hydrocarbon group having a substituent” means that at least a part of hydrogen atoms bonded to the hydrocarbon group is substituted with a substituent.
The hydrocarbon group for W ⁰ or R ^a3 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
As the aliphatic hydrocarbon group for W ⁰ or R ^{a3, a} linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group), an aliphatic cyclic group (monocyclic group, A polycyclic group), and the description thereof is the same as described above.
The aromatic hydrocarbon group for W ⁰ or R ^a3 is a hydrocarbon group having at least one aromatic ring, and this description is the same as described above.

However, W ⁰ may have an oxygen atom or a sulfur atom at an arbitrary position. The phrase “may have an oxygen atom or a sulfur atom at any position” means a carbon atom constituting a hydrocarbon group or a hydrocarbon group having a substituent (including the carbon atom of the substituent portion). ) May be substituted with an oxygen atom or a sulfur atom, or a hydrogen atom bonded to a hydrocarbon group may be substituted with an oxygen atom or a sulfur atom.
The following is an example of W ⁰ having an oxygen atom (O) at an arbitrary position.

［式中、Ｗ^００は炭化水素基であり、Ｒ^ｍは炭素数１〜５のアルキレン基である。］

[Wherein, W ⁰⁰ is a hydrocarbon group, and R ^m is an alkylene group having 1 to 5 carbon atoms. ]

In the above formula, W ⁰⁰ is a hydrocarbon group, and examples thereof include the same as W ⁰ in the formula (a3-1). W ⁰⁰ is preferably an aliphatic hydrocarbon group, more preferably an aliphatic cyclic group (monocyclic group or polycyclic group).
R ^m is preferably linear or branched, preferably an alkylene group having 1 to 3 carbon atoms, and more preferably a methylene group or an ethylene group.

More preferable examples of the structural unit (a3) include more specifically structural units derived from (α-substituted) acrylic acid esters, any of the following general formulas (a3-11) to (a3-13): The structural unit etc. which are represented by these are mentioned. Examples of the structural unit derived from the (α-substituted) acrylate ester include a structural unit in which P ⁰ in the formula (a3-1) is a single bond and W ⁰ is —COOH.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基、または炭素数１〜５のハロゲン化アルキル基である。Ｗ^０１は置換基として−ＯＨ、−ＣＯＯＨ、−ＣＮ、−ＳＯ_２ＮＨ_２及び−ＣＯＮＨ_２からなる群より選択される少なくとも一種の基を有する芳香族炭化水素基である。Ｐ^０２及びＰ^０３はそれぞれ−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−ＮＲ^０−（Ｒ^０は水素原子または炭素数１〜５のアルキル基である）または単結合である。Ｗ^０２は置換基として−ＯＨ、−ＣＯＯＨ、−ＣＮ、−ＳＯ_２ＮＨ_２及び−ＣＯＮＨ_２からなる群より選択される少なくとも一種の基を有する環状の炭化水素基、または、−ＣＯＮＨＣＯ−Ｒ^ａ３２（Ｒ^ａ３２は環状の炭化水素基）であり、任意の位置に酸素原子または硫黄原子を有していてもよい。Ｗ^０３は置換基として−ＯＨ、−ＣＯＯＨ、−ＣＮ、−ＳＯ_２ＮＨ_２及び−ＣＯＮＨ_２からなる群より選択される少なくとも一種の基を有する鎖状の炭化水素基、または、−ＣＯＮＨＣＯ−Ｒ^ａ３３（Ｒ^ａ３３は鎖状の炭化水素基）である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. W ⁰¹ is an aromatic hydrocarbon group having at least one group selected from the group consisting of —OH, —COOH, —CN, —SO ₂ NH ₂ and —CONH ₂ as a substituent. P ⁰² and P ⁰³ are —C (═O) —O—, —C (═O) —NR ⁰ — (R ⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) or a single bond, respectively. . W ⁰² is -OH as a substituent, -COOH, -CN, cyclic hydrocarbon radical having at least one group selected from the group consisting of _-SO 2 NH ₂ and -CONH ₂ or,, ^{-CONHCO-R a32} (R ^a32 is a cyclic hydrocarbon group) and may have an oxygen atom or a sulfur atom at an arbitrary position. W ⁰³ is a chain hydrocarbon group having at least one group selected from the group consisting of —OH, —COOH, —CN, —SO ₂ NH ₂ and —CONH ₂ as a substituent, or —CONHCO—R ^a33 (R ^a33 is a chained hydrocarbon group). ]

[Structural Unit Represented by General Formula (a3-11)]
In the formula (a3-11), R is the same as described for R in the formula (a3-1).
The aromatic hydrocarbon group for W ⁰¹ is the same as that described for the aromatic hydrocarbon group for W ⁰ in formula (a3-1).
Specific examples of preferable structural units represented by general formula (a3-11) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[Structural Unit Represented by General Formula (a3-12)]
In the formula (a3-12), R is the same as described for R in the formula (a3-1).
P ⁰² is —C (═O) —O—, —C (═O) —NR ⁰ — (R ⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) or a single bond, (═O) —O— or a single bond is preferred. The alkyl group for R ⁰ is the same as the alkyl group for R.
The cyclic hydrocarbon group in W ⁰² or R ^a32 is an aliphatic cyclic group (monocyclic group or polycyclic group) exemplified in the description of W ⁰ in the formula (a3-1), aromatic The same thing as each group hydrocarbon group is mentioned.
W ⁰² or R ^a32 may have an oxygen atom or a sulfur atom at an arbitrary position, and this description is the same as the description of W ⁰ in the formula (a3-1).
Specific examples of preferred structural units represented by general formula (a3-12) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[Structural Unit Represented by General Formula (a3-13)]
In the formula (a3-13), R is the same as described for R in the formula (a3-1).
P ⁰³ is —C (═O) —O—, —C (═O) —NR ⁰ — (R ⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) or a single bond, (═O) —O— or a single bond is preferred. The alkyl group for R ⁰ is the same as the alkyl group for R.
The chain hydrocarbon group for W ⁰³ or R ^a33 preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The chain hydrocarbon group in W ⁰³ or R ^a33 may further have a substituent (a) other than —OH, —COOH, —CN, —SO ₂ NH _2, and —CONH ₂ . Examples of the substituent (a) include an alkyl group having 1 to 5 carbon atoms, an aliphatic cyclic group (monocyclic group, polycyclic group), a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, and the like. Can be mentioned. The number of carbon atoms of the aliphatic cyclic group (monocyclic group or polycyclic group) in the substituent (a) is preferably 3 to 30, more preferably 5 to 30, and further preferably 5 to 20 Preferably, 6-15 is especially preferable, and 6-12 is the most preferable. Specifically, for example, a group in which two or more hydrogen atoms have been removed from a monocycloalkane; a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which two or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
Further, straight-chain hydrocarbon group for W ^03, as in the structural unit represented by the following general formula as an example (a3-13-a), may have a plurality of substituents (a), A plurality of substituents (a) may be bonded to each other to form a ring.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基、または炭素数１〜５のハロゲン化アルキル基である。Ｒ^ａ１及びＲ^ａ２はそれぞれ独立に炭素数１〜５のアルキル基、脂肪族環式基（単環式基、多環式基）、フッ素原子、または炭素数１〜５のフッ素化アルキル基である。但し、Ｒ^ａ１とＲ^ａ２とが相互に結合して環を形成してもよい。ｑ^０は１〜４の整数である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. R ^a1 and R ^a2 are each independently an alkyl group having 1 to 5 carbon atoms, an aliphatic cyclic group (monocyclic group or polycyclic group), a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms. is there. However, R ^a1 and R ^a2 may be bonded to each other to form a ring. q ⁰ is an integer of 1 to 4. ]

In the formula (a3-13-a), R is the same as described for R in the formula (a3-1).
The aliphatic cyclic group (monocyclic group or polycyclic group) in R ^a1 and R ^a2 is the same as the aliphatic cyclic group (monocyclic group or polycyclic group) in the substituent (a). is there.
R ^a1 and R ^a2 may be bonded to each other to form a ring. In this ^case, a ^{R a1,} and ^{R a2,} cyclic group is formed by the carbon atoms to which the ^{R a1} and ^{R a2} are bonded together. The cyclic group may be a monocyclic group or a polycyclic group. Specifically, an aliphatic cyclic group (monocyclic group, Examples thereof include groups in which one or more hydrogen atoms have been removed from the monocycloalkane or polycycloalkane exemplified in the description of the polycyclic group).
q ⁰ is preferably 1 or 2, and more preferably 1.

Specific examples of preferable structural units represented by general formula (a3-13) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

When the component (A0) contains the structural unit (a3), the structural unit (a3) in the component (A0) may be one type or two or more types.
When the component (A0) contains the structural unit (a3), the proportion of the structural unit (a3) is preferably 0 to 85 mol% with respect to all the structural units constituting the component (A0). -80 mol% is more preferable. By setting the proportion of the structural unit (a3) to be equal to or higher than the lower limit value, the effects (resolution, lithography characteristics, pattern shape improvement effect) due to the inclusion of the structural unit (a3) can be sufficiently obtained. This makes it easier to balance with other structural units.

(Other ingredients)
・ Structural unit (a4)
The structural unit (a4) is a structural unit containing an acid non-dissociable aliphatic polycyclic group.
In the structural unit (a4), examples of the polycyclic group include the same polycyclic groups as exemplified in the case of the structural unit (a1). For ArF excimer laser, KrF excimer Many things conventionally known as what is used for the resin component of resist compositions, such as for lasers (preferably for ArF excimer lasers), can be used.
In particular, at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

（式中、Ｒは前記のものと同じ意味である。）

(Wherein R has the same meaning as described above.)

  When the structural unit (a4) is contained in the component (A0), the structural unit (a4) is preferably contained in an amount of 1 to 30 mol% based on the total of all the structural units constituting the component (A0). 10 to 20 mol% is more preferable.

In the resist composition of the present invention, the component (A) contains the resin component (A0) having the structural unit (a2) described above.
The component (A0) is preferably a resin component (A1) having a structural unit (a2) and a structural unit (a1).

Specifically, as the component (A0), a polymer compound composed of the structural unit (a2) and the structural unit (a1); a polymer compound composed of the structural unit (a2), the structural unit (a1), and the structural unit (a3), etc. Can be illustrated.
More specifically, the structural unit (a2) is the formula (a2-0-12), the structural unit (a1) is the formula (a1-0-12), and (a3) is the formula (a3- The structural unit represented by 12) can be exemplified as a preferable unit.

In the component (A), as the component (A0), one type may be used alone, or two or more types may be used in combination.
The proportion of the component (A0) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass, further preferably 75% by mass, and 100% by mass with respect to the total mass of the component (A). Most preferred. The effect of this invention improves more that the ratio of this (A0) component is 25 mass% or more.

The mass average molecular weight (Mw) (polystyrene conversion standard by gel permeation chromatography (GPC)) of the component (A0) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, and 2000 to 2000 20000 is most preferred. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
The dispersity (Mw / Mn) is not particularly limited, but is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5. In addition, Mn shows a number average molecular weight.

The component (A) can be obtained by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN).
In addition, the component (A) is used in combination with a chain transfer agent such as, for example, HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH at the time of the polymerization. A —C (CF ₃ ) ₂ —OH group may be introduced into the. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing
As the monomer for deriving each structural unit, a commercially available monomer may be used, or a monomer synthesized by a known method may be used.

<(S) component>
In this invention, (S) component contains the organic solvent (S1) (henceforth (S1) component) which consists of a compound represented by the following general formula (s-1), and the resist composition of this invention is each component. Is dissolved in the component (S).

[(S1) component]
In the present invention, as the component (S1), a compound represented by the general formula (s-1) having a cyclic ether and a monovalent alcohol is used.

［式中、Ｘは単結合または炭素数１〜３のアルキレン基であり、ｎは０〜３の整数である。］

[Wherein, X is a single bond or an alkylene group having 1 to 3 carbon atoms, and n is an integer of 0 to 3. ]

In the general formula (s-1), X represents a single bond or an alkylene group having 1 to 3 carbon atoms. X is a linear, branched, or cyclic alkylene group, and a chain alkylene group is more preferable from the viewpoint of polarity and boiling point.
The chain alkylene group, _{specifically, -CH 2 -, - CH 2} CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 - and the like. _{-CH 2 -, - CH 2 CH} 2 -, - CH 2 CH 2 CH 2 - are _{preferred, -CH 2 -, - CH 2} CH 2 - is particularly preferred, -CH ₂ - is most preferred.
Examples of the cyclic alkylene group include a 1,2-cyclopropylene group.

  In said general formula (s-1), n is an integer of 0-3, 1-3 are preferable from a viewpoint of polarity and a boiling point, and 1-2 are more preferable.

  Specific examples of the compound represented by the general formula (s-1) include compounds represented by the following formulas (s1-1-1) to (s1-1-8).

As the component (S1), one type may be used alone, or two or more types may be used in combination.
The component (S) may be composed only of the component (S1), and has an organic solvent (S2) that does not correspond to the component (S1) (hereinafter referred to as “(S2) component”). There may be. Especially, it is preferable that (S) component of this invention consists of (S1) component and (S2) component.
When (S) component of this invention contains (S1) component, it is preferable that the ratio of (S1) component in (S) component is 5 mass% or more with respect to the total mass of (S) component. It is more preferably 10% by mass or more, and particularly preferably 15% by mass or more. The component (S1) may be 100% by mass. By containing 5% by mass or more of the component (S1), the affinity with the component (A0) having the structural unit (a0) is improved, and the solubility in the component (S) is improved.

[(S2) component]
(S) component of this invention may contain the organic solvent component (S2) (henceforth (S2) component) which does not correspond to the said (S1) component.
As the component (S2), any component that does not correspond to the component (S1) and that can dissolve each component to be used to form a uniform solution may be used, and conventionally known as a solvent for chemically amplified resists. Any one or two or more of them can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ether alkyl such as ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) among these]; cyclic ethers such as dioxane, methyl lactate, Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, Aromatic organics such as dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene A solvent etc. can be mentioned.
(S2) A component may be used independently and may be used as 2 or more types of mixed solvents.
Of these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone, and EL are preferable, and PGMEA, PGME, and cyclohexanone are more preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range. For example, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3. Moreover, when mix | blending cyclohexanone as a polar solvent, the mass ratio of PGMEA: cyclohexanone becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
When the component (S) contains the component (S2), the proportion of the component (S2) in the component (S) is preferably 95% by mass or less, based on the total mass of the component (S), and 90% by mass. % Or less is more preferable and 85% by mass or less is particularly preferable. By setting it within the above range, coating defects of the resist composition are particularly reduced.

<Acid generator component; (B) component>
The component (B) is an acid generator component that generates an acid upon exposure.
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、置換基を有していてもよいアリール基、アルキル基またはアルケニル基を表す。式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよい。Ｚ⁻は対アニオンを表す。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent. Any two of R ¹ ″ to R ³ ″ in formula (b-1) may be bonded to each other to form a ring together with the sulfur atom in the formula. Z ⁻ represents a counter anion. ]

-Cation part In said formula (b-1), as an aryl group which may have a substituent in R < ¹ >''-R< ³ >'', it is a C6-C20 unsubstituted aryl group; Examples include a substituted aryl group in which part or all of the hydrogen atoms of the aryl group are substituted with a substituent.
The unsubstituted aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
Examples of the substituent in the substituted aryl group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (═O), a cyano group, an aryl group, an alkoxyalkyloxy group, and an alkoxycarbonylalkyloxy group. , —C (═O) —O—R ⁶ ′, —O—C (═O) —R ⁷ ′, —O—R ⁸ ′, —O—R ⁹ ′, halogenated alkylsulfonyloxy group, —O ^{-W 1 - [O-R 11} "-S + (R 21") (R 31 ")] .R 6 _{in which x} and the like ^{', R 7', R 8} ' are each 1 to 25 carbon atoms linear, branched or cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a straight-chain or branched aliphatic unsaturated hydrocarbon group having 2 to 5 carbon atoms .R ⁹ 'Represents a nitrogen-containing hydrocarbon group. R ¹¹ ″ has a substituent. Represents an arylene group, an alkylene group or an alkenylene group which may be substituted. R ²¹ ″ and R ³¹ ″ each independently represent an aryl group, alkyl group or alkenyl group which may have a substituent, and may be bonded to each other to form a ring together with the sulfur atom in the formula. x is 1 or 2, and W ¹ represents a (x + 1) -valent linking group.

The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent for the aryl group are aromatic in the description of the divalent linking group for Y ² in the formula (a1-0-2). The same as those mentioned as the substituent of the hydrocarbon group.
The aryl group as a substituent of the aryl group is preferably an aryl group having 6 to 12 carbon atoms, and is preferably a phenyl group or a naphthyl group.

Examples of the alkoxyalkyloxy group as a substituent of the aryl group include:
General formula: -O-C ( ^R47 ) ( ^R48 ) -O- ^R49
[Wherein, R ⁴⁷ and R ⁴⁸ each independently represent a hydrogen atom or a linear or branched alkyl group, and R ⁴⁹ represents an alkyl group. ] Is represented.
In R ⁴⁷ and R ⁴⁸ , the alkyl group preferably has 1 to 5 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group.
At least one of R ⁴⁷ and R ⁴⁸ is preferably a hydrogen atom. In particular, it is more preferable that one is a hydrogen atom and the other is a hydrogen atom or a methyl group.
The alkyl group for R ⁴⁹ preferably has 1 to 15 carbon atoms and may be linear, branched or cyclic.
The linear or branched alkyl group for R ⁴⁹ preferably has 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. Can be mentioned.
The cyclic alkyl group for R ⁴⁹ preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, etc., which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group, etc. And a group obtained by removing one or more hydrogen atoms from the polycycloalkane. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.

Examples of the alkoxycarbonylalkyloxy group as a substituent of the aryl group include:
General formula: —O—R ⁵⁰ —C (═O) —O—R ⁵⁶
[Wherein, R ⁵⁰ represents a linear or branched alkylene group, and R ⁵⁶ represents a tertiary alkyl group. ] Is represented.
The linear or branched alkylene group for R ⁵⁰ preferably has 1 to 5 carbon atoms, such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, or a 1,1-dimethylethylene group. Etc.
As the tertiary alkyl group for R ⁵⁶ , 2-methyl-2-adamantyl group, 2-ethyl-2-adamantyl group, 1-methyl-1-cyclopentyl group, 1-ethyl-1-cyclopentyl group, 1-methyl -1-cyclohexyl group, 1-ethyl-1-cyclohexyl group, 1- (1-adamantyl) -1-methylethyl group, 1- (1-adamantyl) -1-methylpropyl group, 1- (1-adamantyl) -1-methylbutyl group, 1- (1-adamantyl) -1-methylpentyl group; 1- (1-cyclopentyl) -1-methylethyl group, 1- (1-cyclopentyl) -1-methylpropyl group, 1- (1-cyclopentyl) -1-methylbutyl group, 1- (1-cyclopentyl) -1-methylpentyl group; 1- (1-cyclohexyl) -1-methylethyl Group, 1- (1-cyclohexyl) -1-methylpropyl group, 1- (1-cyclohexyl) -1-methylbutyl group, 1- (1-cyclohexyl) -1-methylpentyl group, tert-butyl group, tert -Pentyl group, tert-hexyl group and the like.
Moreover, the general ^formula: the ^{R 56} in the -O-R 50 -C (= O ) -O-R 56, also include groups replaced by ^{R 56} '. R ⁵⁶ ′ is a hydrogen atom, an alkyl group, a fluorinated alkyl group, or an aliphatic cyclic group that may contain a hetero atom.
^Examples of the alkyl group for R ⁵⁶ ′ include the same alkyl groups as those described above for R ⁴⁹ .
^Examples of the fluorinated alkyl group for R ⁵⁶ ′ include groups in which some or all of the hydrogen atoms within the alkyl group for R ⁴⁹ have been substituted with fluorine atoms.
Examples of the aliphatic cyclic group which may contain a hetero atom in R ⁵⁶ ′ include an aliphatic cyclic group containing no hetero atom, an aliphatic cyclic group containing a hetero atom in the ring structure, and an aliphatic cyclic group. Examples include those in which a hydrogen atom in the group is substituted with a heteroatom.
Regarding R ⁵⁶ ′, the aliphatic cyclic group containing no hetero atom includes a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, and the like. Can be mentioned. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
Regarding R ⁵⁶ ′, specific examples of the aliphatic cyclic group containing a hetero atom in the ring structure include groups represented by formulas (L1) to (L7) and (S1) to (S4) described later. It is done.
As for R ⁵⁶ ′, the hydrogen atom in the aliphatic cyclic group is specifically substituted with a hetero atom, specifically, the hydrogen atom in the aliphatic cyclic group is substituted with an oxygen atom (═O), etc. Is mentioned.

^{-C (= O) -O-R} 6 ', -O-C (= O) -R 7', 'R 6 ^{in' -O-R 8, R 7} ', R 8' are each carbon atoms 1 to 25 linear, branched or cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a linear or branched aliphatic unsaturated hydrocarbon group having 2 to 5 carbon atoms. .
The linear or branched saturated hydrocarbon group has 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, and more preferably 4 to 10 carbon atoms.
Examples of the linear saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.
Examples of the branched saturated hydrocarbon group excluding the tertiary alkyl group include, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3 -Methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like can be mentioned.
The linear or branched saturated hydrocarbon group may have a substituent. Examples of the substituent include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), a cyano group, and a carboxy group.
As the alkoxy group as a substituent of the linear or branched saturated hydrocarbon group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, An n-butoxy group and a tert-butoxy group are preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent of the linear or branched saturated hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent of the linear or branched saturated hydrocarbon group, part or all of the hydrogen atoms of the linear or branched saturated hydrocarbon group are the halogen atoms. And a group substituted with.
The cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in R ⁶ ′, R ⁷ ′, and R ⁸ ′ may be either a polycyclic group or a monocyclic group. A group in which one hydrogen atom has been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, and the like. More specifically, one hydrogen atom was removed from a monocycloalkane such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Group and the like.
The cyclic saturated hydrocarbon group may have a substituent. For example, part of the carbon atoms constituting the ring of the cyclic alkyl group may be substituted with a heteroatom, or the hydrogen atom bonded to the ring of the cyclic alkyl group may be substituted with a substituent. Good.
Examples of the former include one or more hydrogen atoms from a heterocycloalkane in which a part of the carbon atoms constituting the ring of the monocycloalkane or polycycloalkane is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Examples include groups other than atoms. The ring structure may have an ester bond (—C (═O) —O—). Specifically, a lactone-containing monocyclic group such as a group obtained by removing one hydrogen atom from γ-butyrolactone, or a group obtained by removing one hydrogen atom from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring. And other lactone-containing polycyclic groups.
Examples of the substituent in the latter example include the same as those described above as the substituent that the linear or branched alkyl group may have, an alkyl group having 1 to 5 carbon atoms, and the like. .
R ⁶ ′, R ⁷ ′, and R ⁸ ′ may be a combination of a linear or branched alkyl group and a cyclic alkyl group.
A combination of a linear or branched alkyl group and a cyclic alkyl group includes a group in which a cyclic alkyl group is bonded as a substituent to a linear or branched alkyl group, and a substituent to the cyclic alkyl group. And a group having a linear or branched alkyl group bonded thereto.
Examples of the linear aliphatic unsaturated hydrocarbon group for R ⁶ ′, R ⁷ ′, and R ⁸ ′ include a vinyl group, a propenyl group (allyl group), and a butynyl group.
Examples of the branched aliphatic unsaturated hydrocarbon group for R ⁶ ′, R ⁷ ′, and R ⁸ ′ include a 1-methylpropenyl group and a 2-methylpropenyl group.
The linear or branched aliphatic unsaturated hydrocarbon group may have a substituent. Examples of the substituent include the same ones as those exemplified as the substituent which the linear or branched alkyl group may have.
Among R ⁷ ′ and R ⁸ ′, among them, the lithography characteristics and the resist pattern shape are good, so that the linear or branched saturated hydrocarbon group having 1 to 15 carbon atoms, or the carbon number 3-20 cyclic saturated hydrocarbon groups are preferred.

Examples of the nitrogen-containing hydrocarbon group for R ⁹ ′ in —O—R ⁹ ′ include those in which a part of carbon atoms in the aromatic hydrocarbon group or the aliphatic hydrocarbon group is substituted with a nitrogen atom. As a preferable example, one or two hydrogen atoms bonded to a nitrogen atom in a linear or branched aminoalkyl group having 1 to 10 carbon atoms are substituted with an alkyl group having 1 to 10 carbon atoms (mono Or di) an alkylaminoalkyl group.
Examples of the halogenated alkyl group in the halogenated alkylsulfonyloxy group include those similar to the halogenated alkyl group as the substituent, and a trifluoromethyl group is particularly preferable.
^{-O-W 1} - "in _{^{x, R 11 [O-R}} 11" -S + (R 21 ") (R 31)]" arylene group which may have a substituent in the alkylene group, an alkenylene group Each include a group in which one hydrogen atom has been removed from an aryl group, an alkyl group or an alkenyl group which may have a substituent in R ¹ ″.
Examples of R ²¹ ″ and R ³¹ ″ include those similar to R ² ″ and R ³ ″ in formula (b-1), respectively.
x is 1 or 2.
W ¹ is a (x + 1) valence, that is, a divalent or trivalent linking group.
Examples of the divalent linking group for W ¹ include the same divalent linking groups as those described above for Y ² , which may be linear, branched or cyclic, and cyclic. preferable. Of these, a group in which two carbonyl groups are combined at both ends of the arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.
Examples of the trivalent linking group in W ¹ include a group obtained by removing one hydrogen atom from a divalent linking group, a group in which a divalent linking group is further bonded to a divalent linking group, and the like. Examples of the divalent linking group include the same divalent linking group of the Y ^2. The trivalent linking group in W ¹ is preferably a group in which three carbonyl groups are combined with an arylene group.

In the case of having —O—W ¹ — [O—R ¹¹ ″ —S ⁺ (R ²¹ ″) (R ³ ″)] _x as a substituent, among R ¹ ″ to R ³ ″, —O—W ¹ — ^{[O-R 11 "-S +} (R 21") (R 3 ")] is preferably have a _x is one.
As a preferred specific example of a cation having —O—W ¹ — [O—R ¹¹ ″ —S ⁺ (R ²¹ ″) (R ³ ″)] _x as a substituent, the cation is represented by the following general formula (ca-0). What is done.

［式中、Ｒ^１１”は置換基を有していてもよいアリーレン基、アルキレン基またはアルケニレン基を表す。Ｒ^２１”、Ｒ^３１”はそれぞれ独立に置換基を有していてもよいアリール基、アルキル基またはアルケニル基を表し、相互に結合して式中のイオウ原子と共に環を形成してもよい。ｘは１または２であり、Ｗ^１は（ｘ＋１）価の連結基を表す。］

[Wherein R ¹¹ ″ represents an arylene group, alkylene group or alkenylene group which may have a substituent. R ²¹ ″ and R ³¹ ″ each independently represents an aryl group which may have a substituent. Represents an alkyl group or an alkenyl group, which may be bonded to each other to form a ring together with the sulfur atom in the formula, x is 1 or 2, and W ¹ represents a (x + 1) -valent linking group.

Examples of the alkyl group which may have a substituent in R ¹ ″ to R ³ ″ include, for example, an unsubstituted alkyl group, and part or all of the hydrogen atoms of the unsubstituted alkyl group are substituted with a substituent. And substituted alkyl groups.
The unsubstituted alkyl group may be linear, branched or cyclic. From the point which is excellent in resolution, a C1-C10 alkyl group is preferable and a C1-C5 alkyl group is more preferable. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decyl group. .
Examples of the substituent in the substituted alkyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (═O), a cyano group, an aryl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, and —C. (═O) —O—R ⁶ ′, —O—C (═O) —R ⁷ ′, —O—R ⁸ ′, —O—R ⁹ ′, halogenated alkylsulfonyloxy group, —O—W ^{1 - [O-R 11 "-S} + (R 21") (R 3 ")] x , and the like.
These are each an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (═O), a cyano group, as the substituents that the substituted aryl group in R ¹ ″ to R ³ ″ may have. Aryl group, alkoxyalkyloxy group, alkoxycarbonylalkyloxy group, —C (═O) —O—R ⁶ ′, —O—C (═O) —R ⁷ ′, —O—R ⁸ ′, —O— R ⁹ ′, a halogenated alkylsulfonyloxy group, —O—W ¹ — [O—R ¹¹ ″ —S ⁺ (R ²¹ ″) (R ³ ″)] _x may be mentioned.

Examples of the alkenyl group which may have a substituent in R ¹ ″ to R ³ ″ include, for example, an unsubstituted alkenyl group, and a part or all of the hydrogen atoms of the unsubstituted alkenyl group are substituted with a substituent. And substituted alkenyl groups.
The unsubstituted alkenyl group is preferably linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, and still more preferably 2 to 4. Specific examples include a vinyl group, a propenyl group (allyl group), a butynyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.
Examples of the substituent in the substituted alkenyl group include the same groups as those described as the substituent that the substituted alkyl group in R ¹ ″ to R ³ ″ may have.

Among the cations (S ⁺ (R ¹ ″) (R ² ″) (R ³ ″)) in the formula (b-1), R ¹ ″ to R ³ ″ each independently have a substituent. Specific examples of preferable aryl group, alkyl group or alkenyl group include cations represented by the following formulas (ca-1-1) to (ca-1-46).

［式中、ｇ１、ｇ２、ｇ３は繰返し数を示し、ｇ１は１〜５の整数であり、ｇ２は０〜２０の整数であり、ｇ３は０〜２０の整数である。］

[Wherein, g1, g2, and g3 represent the number of repetitions, g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20. ]

Any two of R ¹ ″ to R ³ ″ in formula (b-1) may be bonded to each other to form a ring together with the sulfur atom in the formula. In this case, the ring may be saturated or unsaturated. The ring may be monocyclic or polycyclic. For example, when any one or both of R ¹ ″ to R ³ ″ form a ring is a cyclic group (a cyclic alkyl group or an aryl group), when they are bonded, a polycyclic ring ( Fused ring) is formed.
As the ring to be formed, one ring containing a sulfur atom in the ring skeleton in the formula is preferably a 3- to 10-membered ring, particularly a 5- to 7-membered ring, including the sulfur atom. preferable.
The ring may have a hetero atom other than the sulfur atom to which R ¹ ″ to R ³ ″ are bonded as an atom constituting the ring skeleton. Examples of the hetero atom include a sulfur atom, an oxygen atom, and a nitrogen atom.
Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydro A thiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.
Among the cations (S ⁺ (R ¹ ″) (R ² ″) (R ³ ″)) in the formula (b-1), any two of R ¹ ″ to R ³ ″ are bonded to each other. Preferable specific examples when a ring is formed with the sulfur atom in the formula include, for example, cation moieties represented by the following formulas (ca-12) to (ca-15).

［式中、Ｑ^２は単結合、メチレン基、硫黄原子、酸素原子、窒素原子、カルボニル基、−ＳＯ−、−ＳＯ_２−、−ＳＯ_３−、−ＣＯＯ−、−ＣＯＮＨ−または−Ｎ（Ｒ_Ｎ）−（該Ｒ_Ｎは炭素数１〜５のアルキル基である。）であり；Ｒ^８１〜Ｒ^８６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_１〜ｎ_５はそれぞれ独立して０〜３の整数であり、ｎ_６は０〜２の整数である。］

[Wherein Q ² represents a single bond, a methylene group, a sulfur atom, an oxygen atom, a nitrogen atom, a carbonyl group, —SO—, —SO ₂ —, —SO ₃ —, —COO—, —CONH— or —N ( R _N ) — (wherein R _N is an alkyl group having 1 to 5 carbon atoms); R ^{81 to} R ⁸⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl. N _{1 to} n ₅ are each independently an integer of 0 to 3, and n ₆ is an integer of 0 to 2. ]

［式中、ｕは１〜３の整数であり、Ｒ^９は、置換基を有していてもよいフェニル基、ナフチル基またはアルキル基であり、Ｒ^１０は、置換基を有していてもよいフェニル基、ナフチル基、アルキル基、アルコキシ基または水酸基であり、Ｒ^４’は置換基を有していてもよいアルキレン基である。］

[Wherein, u is an integer of 1 to 3, R ⁹ is a phenyl group, a naphthyl group or an alkyl group which may have a substituent, and R ¹⁰ may have a substituent. A good phenyl group, naphthyl group, alkyl group, alkoxy group or hydroxyl group, and R ⁴ ′ is an alkylene group which may have a substituent. ]

In formulas (ca-12) to (ca-13), the alkyl group in R ^{81 to} R ⁸⁶ is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, A methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n _{1 to} n ₆ attached to R ^{81 to} R ⁸⁶ are integers of 2 or more, the plurality of R ^{81 to} R ⁸⁶ may be the same or different.
n ₁ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.
Preferable examples of the cation represented by the formula (ca-12) or (ca-13) include those shown below.

In formulas (ca-14) to (ca-15), u is an integer of 1 to 3, and 1 or 2 is most preferable.
R ⁹ is a phenyl group, a naphthyl group or an alkyl group which may have a substituent.
Examples of the substituent that the phenyl group or naphthyl group in R ⁹ may have include the same substituents as the substituents that the substituted aryl group in R ¹ ″ to R ³ ″ may have. It is done. Specifically, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (═O), a cyano group, an aryl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, —C (═O ) —O—R ⁶ ′, —O—C (═O) —R ⁷ ′, —O—R ⁸ ′, —O—R ⁹ ′, halogenated alkylsulfonyloxy group, —O—W ¹ — [O ^{-R 11 "-S + (R 21} ") (R 3 ")] x , and the like.
As the alkyl group which may have a substituent in R ^9, the same alkyl groups as those which may have a substituent in R ¹ ″ to R ³ ″ are exemplified.
R ¹⁰ is an optionally substituted phenyl group, naphthyl group, alkyl group, alkoxy group or hydroxyl group.
Examples of the substituent that the phenyl group or naphthyl group in R ¹⁰ may have include the same groups as those described as the substituent that the phenyl group or naphthyl group in R ⁹ may have.
Examples of the alkyl group which may have a substituent in R ^{10 and} the alkyl group in the alkoxy group include the same alkyl groups as in R ¹ ″ to R ³ ″.
The alkylene group for R ⁴ ′ is preferably a linear or branched alkylene group. 1-12 are preferable, as for carbon number of this alkylene group, 1-5 are more preferable, 1-3 are more preferable, and 1 or 2 is especially preferable.
Examples of the substituent that the alkylene group for R ⁴ ′ may have include the same groups as those described as the substituent that the substituted alkyl group for R ¹ ″ to R ³ ″ may have. Specifically, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (═O), a cyano group, an aryl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, —C (═O) —O —R ⁶ ′, —O—C (═O) —R ⁷ ′, —O—R ⁸ ′, —O—R ⁹ ′, a halogenated alkylsulfonyloxy group, —O—W ¹ — [O—R ^{11 "-S + (R 21")} (R 3 ")] x , and the like.
Preferable examples of the cation represented by the formula (ca-14) or (ca-15) include those shown below.

In formula (ca-14-1), R ^d is a substituent. Examples of the substituent include the same substituents as those described above as the substituent which the phenyl group or naphthyl group of R ⁹ may have. Specifically, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (═O), a cyano group, an aryl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, —C (═O ) —O—R ⁶ ′, —O—C (═O) —R ⁷ ′, —O—R ⁸ ′, —O—R ⁹ ′, halogenated alkylsulfonyloxy group, —O—W ¹ — [O ^{-R 11 "-S + (R 21} ") (R 3 ")] x , and the like.

The aryl group, alkyl group or alkenyl group which may have a substituent in R ⁵ ″ to R ⁶ ″ in formula (b-2) has a substituent in R ¹ ″ to R ³ ″. Examples of the aryl group, alkyl group or alkenyl group which may be used are the same.
Among R ⁵ ″ to R ⁶ ″, at least one is preferably an aryl group which may have a substituent, and more preferably both are aryl groups which may have a substituent. .
Preferable specific examples of the cation (I ⁺ (R ⁵ ″) (R ⁶ ″)) in the formula (b-2) include diphenyl iodonium, bis (4-tert-butylphenyl) iodonium, and the like.

Anion formula (b-1) Z in ~ (b-2) ^- is a counter anion, ^"R 4" SO ₃ ^- "are preferred.
R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group or an alkenyl group which may have a substituent.
The alkyl group as R ⁴ ″ may be linear, branched or cyclic.
The linear or branched alkyl group as R ⁴ ″ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. preferable.
The cyclic alkyl group as R ⁴ ″ preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
Examples of “R ⁴ ″ SO ₃ ⁻ ” when R ⁴ ″ is an alkyl group include methane sulfonate, n-propane sulfonate, n-butane sulfonate, n-octane sulfonate, 1-adamantane sulfonate, 2-norbornane sulfonate, Examples thereof include alkyl sulfonates such as d-camphor-10-sulfonate.

The halogenated alkyl group as R ⁴ ″ is one in which part or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms, and the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, Among them, a linear or branched alkyl group is more preferable, and it is a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a tert-pentyl group, or an isopentyl group. More preferable examples of the halogen atom substituted with a hydrogen atom include a fluorine atom, a chlorine atom, an iodine atom, a bromine atom, etc. In a halogenated alkyl group, a hydrogen atom of an alkyl group (an alkyl group before halogenation) It is preferable that 50 to 100% of all the hydrogen atoms are substituted with halogen atoms, and all the hydrogen atoms are substituted with halogen atoms. It is more preferable to have.
Here, the halogenated alkyl group is preferably a fluorinated alkyl group. The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
Further, the fluorination rate of the fluorinated alkyl group is preferably 10 to 100%, more preferably 50 to 100%. Particularly, when all the hydrogen atoms are substituted with fluorine atoms, the strength of the acid is increased. preferable.
Specific examples of such a preferred fluorinated alkyl group include a trifluoromethyl group, a heptafluoro-n-propyl group, and a nonafluoro-n-butyl group.

Examples of the aryl group as R ⁴ ″ include the same aryl groups as R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″. Among them, an aryl group having 6 to 20 carbon atoms is preferable. .
Examples of the alkenyl group as R ⁴ ″ include the same alkenyl groups as R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″. Among them, an alkenyl group having 2 to 10 carbon atoms is preferable. .

The alkyl group, halogenated alkyl group, aryl group or alkenyl group in R ⁴ ″ may have a substituent.
“Optionally substituted” means that a part or all of hydrogen atoms in the linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group are substituents. It means that it may be substituted with (an atom or group other than a hydrogen atom).
The number of substituents in R ⁴ ″ may be one or two or more.
Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, and a formula: X ³ -Q ′-[where Q ′ is a divalent linking group containing an oxygen atom, and X ³ represents a substituent. It is a C1-C30 hydrocarbon group which you may have. ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described as the halogen atom and alkyl group in the halogenated alkyl group in R ⁴ ″.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

In the group represented by X ³ —Q′—, Q ′ is a divalent linking group containing an oxygen atom.
Q ′ may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group. A sulfonyl group (—SO ₂ —) may be further linked to the combination.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —O—C (═O) —, —SO _2- O—R ⁹⁴ —O—C (═O) —, —R ⁹⁵ —SO ₂ —O—R ⁹⁴ —O—C (═O) — (wherein R ^{91 to} R ⁹⁵ are each independently alkylene. Group.) And the like.
The alkylene group for R ^{91 to} R ⁹⁵ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ — and the like. Alkylethylene groups; trimethylene groups (n-propylene groups) [—CH ₂ CH ₂ CH ₂ —]; alkyls such as —CH (CH ₃ ) CH ₂ CH ₂ — and —CH ₂ CH (CH ₃ ) CH ₂ — trimethylene; tetramethylene group _[-CH 2 _CH 2 C _{2 CH 2 -]; - CH} (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; pentamethylene group _[-CH 2 _CH 2 CH ₂ CH ₂ CH ₂ —] and the like.
Q ′ is preferably a divalent linking group containing an ester bond or an ether bond, and among them, —R ⁹¹ —O—, —R ⁹² —O—C (═O) — or —C (═O) — O—R ⁹³ —O—C (═O) — is preferred.

In the group represented by ^{X 3} -Q'-, X ³ is a hydrocarbon group of 1 to 30 carbon atoms which may have a substituent.
The hydrocarbon group for X ³ may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic hydrocarbon group include a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Aryl groups such as aryl group, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., from which one is removed. The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be.
Examples of the former include heteroaryl groups in which some of the carbon atoms constituting the ring of the aryl group are substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and aromatic hydrocarbons in the arylalkyl groups. Examples include heteroarylalkyl groups in which some of the carbon atoms constituting the ring are substituted with the above heteroatoms.
Examples of the substituent of the aromatic hydrocarbon group in the latter example include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent of the aromatic hydrocarbon group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The aliphatic hydrocarbon group for X ³ may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In X ³ , the aliphatic hydrocarbon group may be a group in which a part of carbon atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom, and hydrogen constituting the aliphatic hydrocarbon group A part or all of the atoms may be substituted with a substituent containing a hetero atom.
The “heteroatom” in X ³ is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. —, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, — S (= O) ₂ —O— and the like can be mentioned. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic ring). Formula group) is preferred.
The linear saturated hydrocarbon group (alkyl group) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched saturated hydrocarbon group (alkyl group) preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

As an unsaturated hydrocarbon group, it is preferable that carbon number is 2-10, 2-5 are preferable, 2-4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the unsaturated hydrocarbon group is particularly preferably a propenyl group.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms are removed from a monocycloalkane; a group in which one or more hydrogen atoms are removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
When the aliphatic cyclic group does not contain a substituent containing a hetero atom in the ring structure, the aliphatic cyclic group is preferably a polycyclic group, and has one or more hydrogen atoms from the polycycloalkane. Excluded groups are preferred, and most preferred are groups in which one or more hydrogen atoms have been removed from adamantane.
When the aliphatic cyclic group includes a substituent containing a hetero atom in the ring structure, examples of the substituent containing a hetero atom include —O—, —C (═O) —O—, —S—. , —S (═O) ₂ — and —S (═O) ₂ —O— are preferable. Specific examples of the aliphatic cyclic group include groups represented by the following formulas (L1) to (L6) and (S1) to (S4).

［式中、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４−または−Ｓ−Ｒ^９５−であり、Ｒ^９４およびＲ^９５はそれぞれ独立に炭素数１〜５のアルキレン基であり、ｍは０または１の整数である。］

[Wherein, Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —, and R ⁹⁴ and R ⁹⁵ are each independently carbon. An alkylene group of 1 to 5 and m is an integer of 0 or 1.]

In the formula, examples of the alkylene group for Q ″, R ⁹⁴ and R ⁹⁵ include the same alkylene groups as those described above for R ^{91 to} R ⁹³ .
In these aliphatic cyclic groups, a part of hydrogen atoms bonded to carbon atoms constituting the ring structure may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
As said alkyl group, a C1-C5 alkyl group is preferable, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, n-butyl group, and a tert- butyl group.
Examples of the alkoxy group and the halogen atom are the same as those exemplified as the substituent for substituting part or all of the hydrogen atoms.

X ³ is particularly preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, may be a cyclic alkyl group which may have a substituent, and has a substituent. It is preferably an aliphatic cyclic group that may be present.
As the aromatic hydrocarbon group, a phenyl group which may be substituted with a substituent, or a naphthyl group which may be substituted with a substituent is preferable. As the substituent, a fluorine atom is preferable.
The cyclic alkyl group which may have a substituent is preferably a polycyclic cyclic alkyl group which may have a substituent. The polycyclic cyclic alkyl group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, the above (L2) to (L7), (S3) to (S4), and the like.

Among the above, R ⁴ ″ is preferably a halogenated alkyl group or one having X ³ -Q′— as a substituent.
In the case of having X ³ -Q′- as a substituent, R ⁴ ″ is X ³ -Q′-Y ^b- [wherein Q ′ and X ³ are the same as defined above, and Y ^b is a substituent. A C1-C4 alkylene group which may have or a C1-C4 fluorinated alkylene group which may have a substituent.] Is preferable.
In the group represented by X ³ -Q′—Y ^b —, the alkylene group for Y ^b includes the same alkylene groups as those described above for Q ′ having 1 to 4 carbon atoms.
Examples of the fluorinated alkylene group include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^b, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH _{(CH 3) -, - C} (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

Y ^b is preferably a fluorinated alkylene group, and particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the adjacent sulfur atom is fluorinated. Examples of such fluorinated alkylene _{group, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 _{-, - CF (CF 3)} CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, _{-CF (CF 2 CF 3) CF} 2 -; - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH ₂ CH ₂ CF ₂ CF ₂ —, —CH ₂ CF ₂ CF ₂ CF ₂ — and the like can be mentioned.
Of _{these, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, or _CH 2 _CF 2 CF ₂ - is _{preferable, -CF 2 -, - CF 2} CF 2 - or -CF ₂ CF ₂ CF ₂ - is more preferable, -CF ₂ - is particularly preferred.

The alkylene group or fluorinated alkylene group may have a substituent. An alkylene group or a fluorinated alkylene group has a “substituent” means that part or all of the hydrogen atom or fluorine atom in the alkylene group or fluorinated alkylene group is substituted with an atom or group other than a hydrogen atom and a fluorine atom. Means that
Examples of the substituent that the alkylene group or fluorinated alkylene group may have include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a hydroxyl group.

R ⁴ "is ^X 3 ^{-Q'-Y b} - a group represented by ^R 4" SO ₃ ^- Examples of, for example anion represented by any one of the following formulas (b1) ~ (b9) Is mentioned.

［式中、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｔ３は１〜３の整数であり、ｒ１〜ｒ２はそれぞれ独立に０〜３の整数であり、ｇは１〜２０の整数であり、Ｒ^７は置換基であり、ｎ１〜ｎ６はそれぞれ独立に０または１であり、ｖ０〜ｖ６はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ６はそれぞれ独立に０〜３の整数であり、Ｑ”は前記と同じである。］

[Wherein, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 to r2 are each independently 0 to 3] G is an integer of 1 to 20, R ⁷ is a substituent, n1 to n6 are each independently 0 or 1, v0 to v6 are each independently an integer of 0 to 3, w1 to w6 are each independently an integer of 0 to 3, and Q ″ is the same as above.]

As the substituent of R ^7, the same as those mentioned as the substituent that the aliphatic hydrocarbon group may have and the substituent that the aromatic hydrocarbon group may have in the above X ³ Is mentioned.
Code (r1 and r2, W1 to W6) attached to R ⁷ when is an integer of 2 or more, a plurality of the ^{R 7} groups may be the same, respectively, may be different.

As the onium salt-based acid generator, the general formulas (b-1) or (b-2) shown Anion in ^(R 4 "SO ₃ ^-) of the following general formula (b-3) or (b -4) An onium salt acid generator substituted for the anion moiety can also be used (the cation moiety is the same as (b-1) or (b-2)).

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を表す。］

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

In the formula (b-3), X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group preferably has 2 to 6 carbon atoms. More preferably 3 to 5 carbon atoms, most preferably 3 carbon atoms.
In formula (b-4), Y ″ and Z ″ each independently represent a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the carbon number of the alkyl group Is preferably 1 to 10, more preferably 1 to 7 carbon atoms, and most preferably 1 to 3 carbon atoms.
The number of carbon atoms of the X ″ alkylene group or the number of carbon atoms of the Y ″ and Z ″ alkyl groups is preferably as small as possible because the solubility in a resist solvent is good within the above-mentioned range of carbon numbers.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, the strength of the acid increases as the number of hydrogen atoms substituted with fluorine atoms increases, and high-energy light or electron beam of 200 nm or less This is preferable because the transparency to the surface is improved.
The fluorination rate of the alkylene group or alkyl group is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkylene group or a perfluoroalkylene group in which all hydrogen atoms are substituted with fluorine atoms. A fluoroalkyl group;

As the oxime sulfonate acid generator, an oxime sulfonate acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014], [Chem. 18] to [Chem. 19]), International Publication An oxime sulfonate-based acid generator disclosed in the pamphlet of No. 04/074242 (Examples 1 to 40 on pages 65 to 86) can be preferably used.
As the diazomethane acid generator, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

As the component (B), one type of acid generator described above may be used alone, or two or more types may be used in combination.
0.5-60 mass parts is preferable with respect to 100 mass parts of (A) component, as for content of (B) component in a resist composition, 1-50 mass parts is more preferable, and 1-40 mass parts is further. preferable. By setting it within the above range, pattern formation is sufficiently performed. Moreover, when each component of a resist composition is melt | dissolved in the organic solvent, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<Optional component>
[(D) component]
In the resist composition of the present invention, a nitrogen-containing organic compound component (D) (hereinafter referred to as “(D)” which does not fall under the components (A) and (B), as long as the effects of the present invention are not impaired. Component ")).
As the component (D), an acid diffusion control agent, that is, a substance that acts as a quencher that traps the acid generated from the component (A) or the components (A) and (B) by exposure is particularly effective. The present invention is not limited, and a wide variety of products have already been proposed. Examples thereof include amines such as aliphatic amines and aromatic amines, among which aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred.
The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 20 carbon atoms.
Examples of the aliphatic amine include amines (alkyl amines or alkyl alcohol amines) or cyclic amines in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 1 to 20 carbon atoms. It is done.
The alkyl group and the alkyl group in the hydroxyalkyl group may be linear, branched or cyclic.
When the alkyl group is linear or branched, the carbon number thereof is more preferably 2-20, and further preferably 2-8.
When the alkyl group is cyclic (when it is a cycloalkyl group), the carbon number is preferably 3 to 30, more preferably 3 to 20, still more preferably 3 to 15, and 4 to 12 carbon atoms. It is particularly preferred that the number of carbon atoms is 5-10. The alkyl group may be monocyclic or polycyclic. Specific examples include groups in which one or more hydrogen atoms have been removed from monocycloalkane, groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as bicycloalkane, tricycloalkane, and tetracycloalkane. . Specific examples of the monocycloalkane include cyclopentane and cyclohexane. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
Specific examples of the alkylamine include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di-n- Dialkylamines such as heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri- Examples include trialkylamines such as n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, and tri-n-dodecylamine.
Specific examples of the alkyl alcohol amine include diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, tri-n-octanolamine, stearyl diethanolamine, lauryldiethanolamine and the like.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.
Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, tris {2- (1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxyethoxy) ) Ethoxy} ethyl] amine and the like.
Examples of the aromatic amine include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, and tribenzylamine.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

[(E) component]
The resist composition includes at least one selected from the group consisting of organic carboxylic acids and phosphorus oxo acids and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention time stability, and the like. (E) (hereinafter referred to as “component (E)”).
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of phosphinic acid derivatives include phenylphosphinic acid and phosphinic acid esters.
(E) A component may be used individually by 1 type and may use 2 or more types together.
As the component (E), an organic carboxylic acid is preferable, and salicylic acid is particularly preferable.
(E) A component is used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

  The resist composition of the present invention further contains miscible additives as desired, for example, an additional resin for improving the performance of the resist film, a surfactant, a dissolution inhibitor, and a plasticizer for improving coatability. Stabilizers, colorants, antihalation agents, dyes, and the like can be added as appropriate.

  The resist composition of the present invention is excellent in coating property, resolution and lithography properties. The reason why such an effect is obtained is not clear, but is presumed as follows.

Component (A0) of the present invention, the cyclic group (lactone-containing cyclic group containing a polar group at the end, -SO 2 _- with-containing cyclic group, a structural unit containing a carbonate-containing cyclic group (a2). Thereby, the distribution of the component (B) in the film becomes uniform, which is considered to improve the lithography characteristics.

In the resist composition of the present invention, the organic solvent component (S) contains a component (S1) composed of a compound represented by the general formula (s-1).
Since the component (A0) contained in the resist composition of the present invention has the structural unit (a2) having a high polarity as described above, the solubility in an ordinary resist solvent is relatively low. ) Component as a solvent, the solubility of the component (A) in the component (S1) was improved, and as a result, it was considered that the lithography characteristics were improved.
Since the component (S1) has a hydroxyl group, the hydrogen bonding property is larger than that of ordinary polar solvents (γ-butyrolactone, cyclohexanone, etc.). It is considered that this increased the affinity between the (S) component and the polar part of the (A) component. In addition, in recent years, as the component (B), a highly polar compound tends to be used for the purpose of controlling the diffusion of the generated acid. Since the component (S1) of the present invention can uniformly dissolve not only the component (A) but also the highly polar component (B), the lithography properties can be improved.
In addition, when the boiling point of the resist solvent exceeds 200 ° C., the film uniformity of the resist film formed from the resist composition deteriorates during baking, which is a film forming process. The compound represented by the general formula (s-1) used in the present invention has a high hydrogen bonding property, but the boiling point of the compound can withstand this firing (when n = 0-3, the boiling point is 129.8 ° C.-194.1 ° C.) Therefore, it is considered that the film was uniformly dispersed and a resist film having good lithography characteristics was formed.

≪Resist pattern formation method≫
The resist pattern forming method of the present invention includes a step of forming a resist film on a support using the resist composition of the present invention, a step of exposing the resist film, and developing the resist film to form a resist pattern. Forming.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the resist composition of the present invention is applied onto a support with a spinner or the like, and a baking (post-apply bake (PAB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably A resist film is formed by applying for 60 to 90 seconds.
Next, the resist film is exposed through a mask (mask pattern) on which a predetermined pattern is formed using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus, or a mask pattern. After performing selective exposure by drawing or the like by direct irradiation with an electron beam without passing through, baking (post-exposure baking (PEB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 Apply for ~ 90 seconds.
Next, the resist film is developed.
The development treatment is performed using an alkaline developer in the case of an alkali development process, and using a developer (organic developer) containing an organic solvent in the case of a solvent development process.
A rinsing treatment is preferably performed after the development treatment. The rinse treatment is preferably a water rinse using pure water in the case of an alkali development process, and is preferably a rinse solution containing an organic solvent in the case of a solvent development process.
In the case of a solvent development process, after the development process or the rinse process, a process of removing the developer or rinse liquid adhering to the pattern with a supercritical fluid may be performed.
Drying is performed after development or rinsing. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist pattern can be obtained.

The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include organic films such as an organic antireflection film (organic BARC) and a lower organic film in a multilayer resist method.
Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the resist pattern formed on the upper resist film is used as a mask. This is a method of patterning a lower organic film, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, the required thickness can be secured by the lower organic film, so that the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.
In the multilayer resist method, basically, a method of forming a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and one or more intermediate layers between the upper resist film and the lower organic film And a method of forming a multilayer structure of three or more layers (metal thin film etc.) (three-layer resist method).

The wavelength used for the exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. The resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB or EUV.

The exposure method of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be immersion exposure (Liquid Immersion Lithography).
In immersion exposure, the space between the resist film and the lens at the lowest position of the exposure apparatus is previously filled with a solvent (immersion medium) having a refractive index larger than that of air, and exposure (immersion exposure) is performed in that state. It is an exposure method.
As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film to be exposed is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.
Specific examples of the fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Examples thereof include liquids, and those having a boiling point of 70 to 180 ° C are preferable, and those having a boiling point of 80 to 160 ° C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point in the above range since the medium used for immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ° C.). Examples of the perfluoroalkylamine compound include perfluorotributylamine ( Boiling point of 174 ° C.).
As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility, and the like.

Examples of the alkali developer used for the development treatment in the alkali development process include a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used for the development process in the solvent development process is not particularly limited as long as it can dissolve the component (A) (component (A) before exposure). It can be selected as appropriate. Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents can be used.
A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. The surfactant is not particularly limited. For example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0. 0% with respect to the total amount of the organic developer. 5 mass% is more preferable.
The development process can be carried out by a known development method, for example, a method in which a support is immersed in a developer for a certain period of time (dip method), a developer is raised on the surface of the support by surface tension, and is left for a certain period of time. (Paddle method), spraying developer on the surface of the support (spray method), coating the developer while scanning the developer coating nozzle at a constant speed on the support rotating at a constant speed The method to continue (dynamic dispensing method) etc. are mentioned.

As the organic solvent contained in the rinsing liquid used for the rinsing treatment after the development process in the solvent development process, for example, among the organic solvents mentioned as the organic solvent contained in the organic developer, those that are difficult to dissolve the resist pattern are appropriately used. You can select and use. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, and at least one selected from alcohol solvents and ester solvents is preferable. More preferred are alcohol solvents.
The rinse treatment (washing treatment) using the rinse liquid can be performed by a known rinse method. Examples of the method include a method of continuously applying a rinsing liquid on a support rotating at a constant speed (rotary coating method), a method of immersing the support in a rinsing liquid for a predetermined time (dip method), and the surface of the support. And a method of spraying a rinse liquid (spray method).

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
[Formation of resist film]
The resist composition of each example was applied onto an 8-inch silicon wafer using a spinner, pre-baked (PAB) at a hot plate temperature of 100 ° C. for 60 seconds, and dried to form a resist film. Formed.

<Evaluation of solubility and applicability>
The solubility and applicability evaluation of the resin (A) -1 as the component (A) in the component (S) with different mixing ratios were performed. The results are shown in Table 1. The solid content with respect to the component (S) of (A) -1 was 10% by mass, and stirring was performed with ultrasonic waves in water for 5 minutes to evaluate the solubility.

Moreover, each abbreviation (S1) -1, (S2) -1 and resin (A) -1 show the following.
(S1) -1: Tetrahydrofurfuryl alcohol.
(S2) -1: PGMEA.
(A) -1: The following resin (A) -1.

［Ｍｗ＝７６００，Ｍｎ／Ｍｗ＝１.６、ｌ／ｍ／ｎ／ｏ／ｐ＝３５／２２／１８／１３／１２（モル比）。］

[Mw = 7600, Mn / Mw = 1.6, l / m / n / o / p = 35/22/18/13/12 (molar ratio). ]

  From the above results, the component (S1) -1 (tetrahydrofurfuryl alcohol) which is the component (S1) is excellent in the solubility of the resin and the coating property regardless of the mixing ratio with the other solvent component (S2). I was able to confirm.

<Adjustment of resist composition>
[Examples 1-7, Comparative Examples 1-7]
The resist composition was prepared by mixing and dissolving the components shown in Table 2.

In Table 2, the numerical value in [] of (A) component-(S) component is a compounding quantity (mass part). Moreover, each abbreviation shows the following, respectively.
(A) -1: The resin component (A) -1.
(A) -2: The following resin component (A) -2.
(A) -3: The following resin component (A) -3.
(A) -4: The following resin component (A) -4.
(B) -6: The following acid generator (B) -6.
(B) -7: The following compound (B) -7.
(E) -1: salicylic acid.
(S1) -1: the solvent component (S1) -1.
(S2) -1: the solvent component (S2) -1.
(S2) -2: PGME.
(S2) -3: Anisole.
(S2) -4: Cyclohexane.
(S2) -5: γ-butyrolactone.

［Ｍｗ＝７６００，Ｍｎ／Ｍｗ＝１．５４、ｌ／ｍ＝５０／５０（モル比）。］

[Mw = 7600, Mn / Mw = 1.54, 1 / m = 50/50 (molar ratio). ]

［Ｍｗ＝７６００，Ｍｎ／Ｍｗ＝１．５４、ｌ／ｍ＝５０／５０（モル比）。］

[Mw = 7600, Mn / Mw = 1.54, 1 / m = 50/50 (molar ratio). ]

［Ｍｗ＝７６００，Ｍｎ／Ｍｗ＝１．５４、ｌ／ｍ＝５０／５０（モル比）。］

[Mw = 7600, Mn / Mw = 1.54, 1 / m = 50/50 (molar ratio). ]

  Using the obtained resist composition, a resist pattern was formed according to the following procedure, and the following evaluations were performed.

[Formation of resist pattern]
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer using a spinner, and baked at 205 ° C. for 90 seconds on a hot plate and dried. Thus, an organic antireflection film having a film thickness of 82 nm was formed.
Then, the resist composition of each example is applied onto the organic antireflection film using a spinner, prebaked (PAB) at a hot plate temperature of 100 ° C. for 60 seconds, and dried. A resist film having a thickness of 130 nm (Examples 1 and 2, Comparative Examples 1 to 4) and a thickness of 100 nm (Examples 3 to 7 and Comparative Examples 5 to 7) was formed. In Comparative Example 4, no film could be formed, and the following evaluation was not performed.
Next, an ArF excimer laser (193 nm) was passed through a mask pattern (6% halftone) using an ArF exposure apparatus NSR-S302A (manufactured by Nikon Corporation; NA (numerical aperture) = 0.60, σ = 0.75). Selectively irradiated.
Then, a post-exposure heating (PEB) treatment at 95 ° C. for 60 seconds was performed, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C. Manufactured for 30 seconds, rinsed with pure water for 15 seconds, and then shaken and dried.
Subsequently, post-baking was performed on a hot plate at 100 ° C. (Examples 1 to 4, Comparative Examples 1 to 3, 5, and 6) for 60 seconds.
As a result, in each example, a 1: 1 line and space (LS) pattern having a line width of 130 nm and a pitch of 260 nm was formed.
The optimum exposure dose Eop (mJ / cm ² ; sensitivity) for forming the LS pattern was determined. The results are also shown in Table 3.

[Exposure margin (EL margin) evaluation]
The exposure amount when the line of the LS pattern is formed within the range of ± 10% (117 nm to 143 nm) of the target dimension (line width 130 nm) with the optimum exposure amount Eop is obtained. )
EL margin (%) = (| E1-E2 | / Eop) × 100
E1: Exposure amount (mJ / cm ² ) when an LS pattern having a line width of 117 nm was formed
E2: exposure amount (mJ / cm ² ) when an LS pattern having a line width of 143 nm was formed
Note that the larger the value of the EL margin, the smaller the change amount of the pattern size accompanying the change in the exposure amount.

[LWR (line width roughness) evaluation]
In the LS pattern with a line width of 130 nm and a pitch of 260 nm formed by the Eop, the line width was changed to a line width by a length measurement SEM (scanning electron microscope, acceleration voltage 300 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). 400 points were measured in the longitudinal direction, and a triple value (3s) of the standard deviation (s) was obtained from the result, and a value averaged for 3s at 400 points was calculated as a scale indicating LWR. The results are shown in Table 3.
A smaller value of 3s means that the roughness of the line width is smaller, and an LS pattern having a more uniform width is obtained.

  From the results of Table 3, the resist compositions of Examples 1 to 7 are superior in coating properties as compared to Comparative Example 4, and have LWR and EL margins as compared to the resist compositions of Comparative Examples 1 to 3 and 5 to 7. It was confirmed that the lithography properties such as the above were excellent.

Claims (3)

A resist composition containing a base material component (A) whose solubility in a developing solution is changed by the action of an acid, an acid generator component (B) that generates an acid upon exposure, and an organic solvent component (S),
In the said organic solvent component (S) , the organic solvent (S1) which consists of a compound represented by the following general formula (s-1) is contained in the ratio of 5-80 mass% ,
The substrate component (A) contains a resin component (A0) having a structural unit (a2) containing a —SO ₂ — containing cyclic group, a carbonate containing cyclic group, or a lactone containing cyclic group. A resist composition.

[Wherein, X is a single bond or an alkylene group having 1 to 3 carbon atoms, and n is an integer of 0 to 3. ] The resist composition according to claim 1 , wherein the substrate component (A0) is a resin component (A1) whose polarity increases by the action of an acid. On a support, comprising the step of forming a resist process for forming a resist film using the composition, a resist pattern by developing conducting exposure of the resist film, and the resist film according to claim 1 or 2 Resist pattern forming method.