JP6464010B2 - Resist pattern forming method - Google Patents

Description

  The present invention relates to a resist pattern forming method.

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 to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film.
A resist material in which the exposed portion 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, the exposure light source is generally shortened in wavelength (increased 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 electron beams having shorter wavelengths (higher energy) than these excimer lasers, EUV (extreme ultraviolet rays), X-rays, and the like.

  As a technique for providing a finer pattern, a double patterning process has been proposed in which patterning is performed a plurality of times to form a resist pattern. According to the double patterning process, for example, the first resist pattern is formed on the support by using the first resist composition to form the first resist pattern, and then the first resist pattern is formed. By performing patterning on the support using the second resist composition, a resist pattern having a resolution higher than that of the resist pattern formed by one patterning can be formed.

In Patent Document 1, a first resist pattern is formed on a support, an SiO ₂ film is formed on the surface of the support and the first resist pattern, and etching is performed using the SiO ₂ film as a sacrificial film. Then, a method for forming a second pattern of the SiO ₂ film by removing the first resist pattern is described.

JP2013-164509A

However, the method as described above has a problem that a plurality of exposures are required or the number of steps is large and the process is complicated, and there is still room for improvement in the method for forming a fine pattern.
This invention is made | formed in view of the said situation, Comprising: It aims at providing the pattern formation method which can form a fine pattern.

  In the first aspect of the present invention, a resist composition is coated on a support, a positive resist film is formed, the positive resist film is exposed, and alkali development is performed to form a first resist pattern. Obtained by the process A, the process B for applying a solution containing an acid or a thermal acid generator so as to cover the first resist pattern, and forming the first layer, and the processes A to B. Heating the structure including the first resist pattern, and changing the solubility of the first resist pattern in the developer by the action of the acid in the first layer; and the coated first Step D of forming the second resist pattern by developing the resist pattern in an organic solvent, removing regions other than the region in which the solubility of the first resist pattern in the developing solution is changed, and the second resist pattern Dissolve A pattern reversal composition containing no organic solvent was applied to form a pattern reversal film, and the pattern reversal film was removed while removing the second resist pattern by alkali development using an alkali developer. It is a resist pattern formation method characterized by having the process E which forms a 3rd pattern by patterning.

  ADVANTAGE OF THE INVENTION According to this invention, the pattern formation method which can form a fine pattern can be provided.

It is a figure which shows an example of the schematic process of the resist pattern formation method of this invention.

In the present specification and claims, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
The “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
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.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Fluorinated alkyl group” or “fluorinated alkylene group” refers to a group in which part or all of the hydrogen atoms of an alkyl group or alkylene group are substituted with fluorine atoms.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“A 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 (R ^α ) for substituting 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 or a halogenated group having 1 to 5 carbon atoms. Examples thereof include an alkyl group and a hydroxyalkyl group. 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”.
“A structural unit derived from 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 derivatives include those in which the hydrogen atom at the α-position may be substituted with a substituent, the hydrogen atom of the hydroxyl group of hydroxystyrene substituted with an organic group, and the hydrogen atom at the α-position substituted with a substituent. Examples include those in which a substituent other than a hydroxyl group is bonded to a good benzene ring of hydroxystyrene. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same substituents as those mentioned as the substituent at the α-position in the α-substituted acrylic ester.
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. These derivatives include those obtained by substituting the hydrogen atom of the carboxy group of vinyl benzoic acid with an organic group, which may be substituted with a hydrogen atom at the α-position, and the hydrogen atom at the α-position with a substituent. Examples thereof include those in which a substituent other than a hydroxyl group and a carboxy group is bonded to the benzene ring of vinyl benzoic acid. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
“Styrene derivative” means one in which the α-position hydrogen atom of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group.
“Structural unit derived from styrene” and “structural unit derived from styrene derivative” mean a structural unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.
The alkyl group as a substituent at the α-position is preferably a linear or branched alkyl group, specifically, an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group). , N-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like.
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 a group in which part or all of the hydrogen atoms of the “alkyl group as the substituent at the α-position” are substituted with a hydroxyl group. 1-5 are preferable and, as for the number of the hydroxyl groups in this hydroxyalkyl group, 1 is the most preferable.
When it is described as “may have a substituent”, when a hydrogen atom (—H) is substituted with a monovalent group, and when a methylene group (—CH ₂ —) is substituted with a divalent group Including both.
“Exposure” is a concept including general irradiation of radiation.

≪Resist pattern formation method≫
The present invention comprises a step A of applying a resist composition on a support, forming a positive resist film, exposing the positive resist film, and performing alkali development to form a first resist pattern; A step B of applying a solution containing an acid or a thermal acid generator so as to cover the first resist pattern to form a first layer; and the first resist obtained in the steps A to B. Heating the structure including the pattern, and changing the solubility of the first resist pattern in the developer by the action of the acid in the first layer; and Step D for forming a second resist pattern by solvent development, removing regions other than the region where the solubility of the first resist pattern in the developer is changed, and organic solution not dissolving the second resist pattern A pattern reversal film is formed by coating a pattern reversal film, and the pattern reversal film is patterned while removing the second resist pattern by alkali development using an alkali developer. A method for forming a resist pattern, comprising a step E of forming a third pattern.
Hereinafter, the resist pattern forming method of the present invention will be described with reference to the drawings.

[Step A]
Step A is a step of forming a positive resist film on a support, exposing the positive resist film, and performing alkali development to form a first resist pattern. In step A, a first resist pattern 1P is formed on the support 1 as shown in FIG.
[Support]
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 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 development process can be performed 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.

  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).

<Positive resist composition>
In step A, the positive resist composition used for forming the first resist pattern can employ a positive resist composition that generates an acid upon exposure and has increased solubility in a developer due to the action of the acid. .
The positive resist composition (hereinafter sometimes referred to as “resist composition”) has a base component (A) (hereinafter referred to as “component (A)”) whose solubility in a developing solution is changed by the action of an acid. It is also preferable to contain.
When a resist film is formed using such a resist composition and the resist film is selectively exposed, an acid is generated in the exposed area, and the solubility of the component (A) in an alkaline developer is caused by the action of the acid. On the other hand, since the solubility of the component (A) in the alkali developer does not change in the unexposed area, a difference in solubility in the developer occurs between the exposed area and the unexposed area. Therefore, when the resist film is developed, the exposed portion is dissolved and removed, and a positive resist pattern is formed.

In the present invention, the resist composition has an acid generating ability to generate an acid upon exposure, and the (A) component may generate an acid upon exposure, and is added separately from the (A) component. The agent component may generate an acid upon exposure.
Specifically, in the present invention, the resist composition is
(1) It may contain an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “component (B)”);
(2) The component (A) may be a component that generates an acid upon exposure;
(3) The component (A) is a component that generates an acid upon exposure, and may further contain a component (B).
That is, in the case of the above (2) and (3), the component (A) is a “base material component that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid”. When the component (A) is a base material component that generates an acid upon exposure and has increased solubility in a developer due to the action of the acid, the component (A1) described later generates an acid upon exposure, and A polymer compound whose solubility in a developer is increased by the action of an acid is preferable. As such a polymer compound, a resin having a structural unit that generates an acid upon exposure can be used. A well-known thing can be used as a structural unit which generate | occur | produces an acid by exposure.
In the present invention, the resist composition is particularly preferably the case (1).

<(A) component>
In the present invention, the “base component” 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 in addition, a nano-level photosensitive resin 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 weight average molecular weight by GPC (gel permeation chromatography) is used.
As the component (A), a resin may be used, a low molecular compound may be used, or these may be used in combination.
The component (A) has increased solubility in a developer due to the action of an acid.
In the present invention, the component (A) may generate an acid upon exposure.

In the present invention, the component (A) includes a structural unit containing an acid-decomposable group whose polarity increases by the action of an acid (hereinafter sometimes referred to as “structural unit (a1)”) and a —SO ₂ — containing cyclic group. A polymer compound (A1) having a structural unit having a group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a heterocyclic group other than these (hereinafter also referred to as “structural unit (a2)”) It is preferable that it contains.

(Structural unit (a1))
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid.
The “acid-decomposable group” is an acid-decomposable group that can cleave at least part of bonds in the structure of the acid-decomposable group by the action of an acid.
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 groups 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).
Here, “acid-dissociable group” means
(I) an acid-dissociable group capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid, or
(Ii) a group capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by further decarboxylation reaction after partial bond cleavage by the action of an acid ,
Both.
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 (A1) increases. As the polarity increases, the solubility in the developer changes relatively, and when the developer is an organic 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.
Among the polar groups, examples of the acid dissociable group that protects a carboxy group or a hydroxyl group include an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter referred to as “acetal acid dissociable for convenience”). Group ”).

［式中、Ｒａ’^１、Ｒａ’^２は水素原子またはアルキル基、Ｒａ’^３は炭化水素基、Ｒａ’^３は、Ｒａ’^１、Ｒａ’^２のいずれかと結合して環を形成してもよい。＊は結合手を意味する。］

[Wherein, Ra ′ ¹ and Ra ′ ² are hydrogen atoms or alkyl groups, Ra ′ ³ is a hydrocarbon group, and Ra ′ ³ may be bonded to either Ra ′ ¹ or Ra ′ ² to form a ring. Good. * Means a bond. ]

In formula (a1-r-1), Ra ′ ¹ and Ra ′ ² are exemplified as substituents that may be bonded to the α-position carbon atom in the description of the α-substituted acrylate ester described above. Examples thereof include the same as the alkyl group, preferably a methyl group or an ethyl group, and most preferably a methyl group.

The hydrocarbon group for Ra ′ ³ is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms; a linear or branched alkyl group is preferable, specifically , Methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, 1,1-dimethylethyl group, 1,1-diethylpropyl group 2,2-dimethylpropyl group, 2,2, -dimethylbutyl group and the like can be mentioned.

When Ra ′ ³ is a cyclic hydrocarbon group, it may be aliphatic or aromatic, may be polycyclic, or may be monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane and cyclooctane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

In the case of an aromatic hydrocarbon group, specific examples of the aromatic ring contained include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene; carbon atoms constituting the aromatic hydrocarbon ring An aromatic heterocycle partially substituted with a heteroatom; 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 one hydrogen atom from the aromatic hydrocarbon ring (aryl group); a group in which one of the hydrogen atoms of the aryl group is substituted with an alkylene group (for example, Benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl 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.

When Ra ′ ³ is bonded to either Ra ′ ¹ or Ra ′ ² to form a ring, 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.

  Among the polar groups, examples of the acid dissociable group that protects the carboxy group include an acid dissociable group represented by the following general formula (a1-r-2) (the following formula (a1-r-2) Among the acid dissociable groups represented by), those composed of an alkyl group may hereinafter be referred to as “tertiary alkyl ester type acid dissociable groups” for convenience).

［式中、Ｒａ’^４〜Ｒａ’^６は炭化水素基であり、Ｒａ’^５、Ｒａ’^６は互いに結合して環を形成してもよい。＊は結合手を意味する。］

[Wherein, Ra ′ ^{4 to} Ra ′ ⁶ are hydrocarbon groups, and Ra ′ ⁵ and Ra ′ ⁶ may be bonded to each other to form a ring. * Means a bond. ]

As the hydrocarbon group for Ra ′ ^{4 to} Ra ′ ^6, the same groups as those described above for Ra ′ ³ can be mentioned. Ra ′ ⁴ is preferably an alkyl group having 1 to 5 carbon atoms. In the case where Ra ′ ⁵ and Ra ′ ⁶ are bonded to each other to form a ring, a group represented by general formula (a1-r2-1) shown below can be given.
On the other hand, when Ra ′ ^{4 to} Ra ′ ⁶ are not bonded to each other and are independent hydrocarbon groups, groups represented by the following general formula (a1-r2-2) are exemplified.

［式中、Ｒａ’^１０は炭素数１〜１０のアルキル基、Ｒａ’^１１はＲａ’^１０が結合した炭素原子と共に脂肪族環式基を形成する基、Ｒａ’^１２〜Ｒａ’^１４は、それぞれ独立に炭化水素基を示す。＊は結合手を意味する。］

[Wherein, Ra ′ ¹⁰ is an alkyl group having 1 to ¹⁰ carbon atoms, Ra ′ ¹¹ is a group that forms an aliphatic cyclic group together with a carbon atom to which Ra ′ ¹⁰ is bonded, and Ra ′ ^{12 to} Ra ′ ¹⁴ are Independently represents a hydrocarbon group. * Means a bond. ]

In formula (a1-r2-1), the alkyl group of the alkyl group having 1 to ¹⁰ carbon atoms of Ra ′ ¹⁰ is a linear or branched alkyl group of Ra ′ ³ in formula (a1-r-1) The groups mentioned as are preferred. Wherein (a1-r2-1), Ra 'aliphatic cyclic ^{group 11} is configured, Ra in formula (a1-r-1)' group listed as a cyclic alkyl group of ³ is preferred.

In formula (a1-r2-2), Ra ′ ¹² and Ra ′ ¹⁴ are preferably each independently an alkyl group having 1 to 10 carbon atoms, and the alkyl group is represented by Ra in formula (a1-r-1). 'The group mentioned as a linear or branched alkyl group of ³ is more preferable, It is more preferable that it is a C1-C5 linear alkyl group, It is especially preferable that it is a methyl group or an ethyl group .
In formula (a1-r2-2), Ra ′ ¹³ is a linear, branched or cyclic alkyl group exemplified as the hydrocarbon group for Ra ′ ³ in formula (a1-r-1). Is preferred. Among these, a group exemplified as the cyclic alkyl group for Ra ′ ³ is more preferable.

  Specific examples of the formula (a1-r2-1) are given below. In the following formula, “*” indicates a bond.

  Specific examples of the formula (a1-r2-2) are given below.

  Examples of the acid dissociable group for protecting the hydroxyl group among the polar groups include, for example, an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as “tertiary alkyloxycarbonyl acid for convenience”). Sometimes referred to as a “dissociable group”).

［式中、Ｒａ’^７〜Ｒａ’^９はアルキル基を示す。＊は結合手を意味する。］

[Wherein, Ra ′ ^{7 to} Ra ′ ⁹ represent an alkyl group. * Means a bond. ]

In formula (a1-r-3), Ra ′ ^{7 to} Ra ′ ⁹ are preferably an alkyl group having 1 to 5 carbon atoms, and more preferably 1 to 3 groups.
Moreover, it is preferable that the total carbon number of each alkyl group is 3-7, it is more preferable that it is 3-5, and it is most preferable that it is 3-4.

  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, and an acid whose polarity is increased by the action of an acid. A structural unit containing a decomposable group; a structural unit in which at least a part of hydrogen atoms in the hydroxyl group of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative is protected by a substituent containing the acid-decomposable group; vinylbenzoic acid or Examples include a structural unit in which at least a part of hydrogen atoms in —C (═O) —OH of a structural unit derived from a vinylbenzoic acid derivative is protected by a substituent containing the acid-decomposable group.

Among the above, the structural unit (a1) is preferably 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.
As the structural unit (a1), structural units represented by general formula (a1-1) or (a1-2) 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。Ｖａ^１はエーテル結合、ウレタン結合、又はアミド結合を有していてもよい２価の炭化水素基であり、ｎ_ａ１は０〜２であり、Ｒａ^１は上記式（ａ１−ｒ−１）〜（ａ１−ｒ−２）で表される酸解離性基である。Ｗａ^１はｎ_ａ２＋１価の炭化水素基であり、ｎ_ａ２は１〜３であり、Ｒａ^２は上記式（ａ１−ｒ−１）または（ａ１−ｒ−３）で表される酸解離性基である。］

[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. Va ¹ is a divalent hydrocarbon group that may have an ether bond, a urethane bond, or an amide bond, n _a1 is 0 to 2, and Ra ¹ is the above formula (a1-r-1) to It is an acid dissociable group represented by (a1-r-2). Wa ¹ is a n _a2 +1 valent hydrocarbon group, n _a2 is 1 to 3, and Ra ² is an acid dissociation property represented by the above formula (a1-r-1) or (a1-r-3). It is a group. ]

In the general formula (a1-1), the alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, Examples include propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms 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.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is most preferably a hydrogen atom or a methyl group in terms of industrial availability.
The hydrocarbon group for Va ¹ 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 a divalent hydrocarbon group in Va ¹ 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.
Examples of Va ¹ include those in which the divalent hydrocarbon group is bonded through an ether bond, a urethane bond, or an amide bond.

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.

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 aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ 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.

In the formula (a1-2), the n _a2 +1 valent hydrocarbon group in Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group including a ring in the structure, or a linear or branched aliphatic hydrocarbon group. It includes a group formed by combining an aliphatic hydrocarbon group in the structure containing a ring, and specific examples thereof include the same groups as Va ¹ of the aforementioned formula (a1-1).
The n _a2 +1 valence is preferably 2 to 4, and more preferably 2 or 3.

  As the formula (a1-2), a structural unit represented by general formula (a1-2-01) shown below is particularly desirable.

In formula (a1-2-01), Ra ² is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-3). n _a2 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1. c is an integer of 0 to 3, preferably 0 or 1, and more preferably 1. R is the same as described above.
Specific examples of the above formulas (a1-1) and (a1-2) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

  The proportion of the structural unit (a1) in the component (A) is preferably from 20 to 80 mol%, more preferably from 20 to 75 mol%, more preferably from 25 to 70 mol%, based on all structural units constituting the component (A). Is more preferable. By setting the lower limit value or more, lithography properties such as sensitivity, resolution, and LWR are also improved. Moreover, the balance with another structural unit can be taken by making it below an upper limit.

(Structural unit (a2))
In the present invention, the resin component preferably contains a structural unit (a2) having a —SO ₂ -containing cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a heterocyclic group other than these. .
The —SO ₂ — containing cyclic group, lactone containing cyclic group, carbonate containing cyclic group or other heterocyclic group of the structural unit (a2) is used when the component (A) is used for forming a resist film. It is effective in improving the adhesion of the resist film to the substrate.
In addition, when the above-described structural unit (a1) includes a —SO ₂ — containing cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a heterocyclic group other than these in the structure, the structural unit Corresponds to the structural unit (a2), but such a structural unit corresponds to the structural unit (a1) and does not correspond to the structural unit (a2).

  The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｙａ^２１は単結合または２価の連結基であり、Ｌａ^２１は−Ｏ−、−ＣＯＯ−、−ＣＯＮ（Ｒ’）−、−ＯＣＯ−、−ＣＯＮＨＣＯ−又は−ＣＯＮＨＣＳ−であり、Ｒ’は水素原子またはメチル基を示す。ただしＬａ^２１が−Ｏ−の場合、Ｙａ^２１は−ＣＯ−にはならない。Ｒａ^２１は−ＳＯ_２−含有環式基、ラクトン含有環式基、カーボネート含有環式基又はこれら以外の複素環式基である。］

[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, Ya ²¹ is a single bond or a divalent linking group, and La ²¹ is —O -, -COO-, -CON (R ')-, -OCO-, -CONHCO- or -CONHCS-, wherein R' represents a hydrogen atom or a methyl group. However, when La ²¹ is —O—, Ya ²¹ is not —CO—. Ra ²¹ is a —SO ₂ -containing cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a heterocyclic group other than these. ]

The divalent linking group of Ya ²¹ is not particularly limited, and preferred examples thereof include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom.

(Divalent hydrocarbon group which may have a substituent)
The hydrocarbon group as the divalent linking group 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 may be saturated or unsaturated, and is usually preferably saturated.
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. Specifically, the above-described formula (a1- The group illustrated by Va ¹ in 1) is mentioned.

  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, and a carbonyl group.

As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure (excluding two hydrogen atoms from the aliphatic hydrocarbon ring) Group), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and the cyclic aliphatic hydrocarbon group is a linear or branched chain fatty acid. Group intervening in the middle of the group hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
Specific examples of the cyclic aliphatic hydrocarbon group include the groups exemplified for Va ¹ in the above formula (a1-1).
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl 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.
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 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 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.
In the cyclic aliphatic hydrocarbon group, a part of carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing the hetero atom, —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, and —S (═O) ₂ —O— are preferable.

Specific examples of the aromatic hydrocarbon group as the divalent hydrocarbon group include groups exemplified by Va ¹ in the above formula (a1-1).
In the aromatic hydrocarbon group, a hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in 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, and a hydroxyl 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 alkoxy group, the halogen atom and the halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

(Divalent linking group containing a hetero atom)
The hetero atom in the divalent linking group containing a hetero atom 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.

When Ya ²¹ is a divalent linking group containing a hetero atom, preferred examples of the linking group include —O—, —C (═O) —O—, —C (═O) —, and —O—C. (═O) —O—, —C (═O) —NH—, —NH—, —NH—C (═NH) — (H may be substituted with a substituent such as an alkyl group or an acyl group). _{.), - S -, -} S (= O) 2 -, - S (= O) 2 -O-, the formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 - C (═O) —O—, —C (═O) —O—Y ²¹ , [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — or —Y ²¹ —O—C (= O) a group represented by —Y ²² —, wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, m 'is an integer of 0-3. ] Etc. are mentioned.
When the divalent linking group containing a hetero atom is —C (═O) —NH—, —NH—, —NH—C (═NH) —, H is a substituent such as an alkyl group or acyl. May be substituted. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 -C (= O) -O -, - C (= O) -O-Y 21, - [Y 21 -C ( ═O) —O] _{m ′} —Y ²² — or —Y ²¹ —O—C (═O) —Y ²² —, wherein Y ²¹ and Y ²² each independently have a substituent. It is a good divalent hydrocarbon group. Examples of the divalent hydrocarbon group include those similar to the “divalent hydrocarbon group optionally having substituent (s)” mentioned in the description of the divalent linking group.
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.

In the present invention, Ya ²¹ is a single bond, an ester bond [—C (═O) —O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. Preferably there is.

In the formula (a2-1), Ra ²¹ represents a —SO ₂ — containing cyclic group, a lactone-containing cyclic group, a heterocyclic group, or a carbonate-containing cyclic group.

The “—SO ₂ -containing cyclic group” refers to a cyclic group containing a ring containing —SO ₂ — in the ring skeleton, specifically, the sulfur atom (S) in —SO ₂ — is It is a cyclic group that forms 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. More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by general formulas (a5-r-1) to (a5-r-4) shown below.

［式中、Ｒａ’^５１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、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；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、ｎ’は０〜２の整数である。］

[Wherein, Ra ′ ⁵¹ independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom or an alkyl group; 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, and n ′ is 0 to 2 Is an integer. ]

In general formulas (a5-r-1) to (a5-r-4), A ″ is the same as A ″ in general formulas (a2-r-1) to (a2-r-7) described later. . Examples of the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in Ra ′ ⁵¹ include general formulas (a2-r-1) to ( It is the same as Ra ′ ^{21 in} a2-r-7).

  Specific examples of groups represented by general formulas (a5-r-1) to (a5-r-4) are given below. “Ac” in the formula represents an acetyl group.

In the present invention, when the structural unit (a2) contains a —SO ₂ — containing cyclic group, among them, the group represented by the general formula (a5-r-1) is preferable, and the chemical formula (r-sl -1-1), (r-sl-1-18), (r-sl-3-1) and (r-sl-4-1) are selected from the group consisting of groups It is more preferable to use at least one kind, and a group represented by the chemical formula (r-sl-1-1) is most preferable.

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.
Any lactone-containing cyclic group can be used without any particular limitation. Specific examples include groups represented by general formulas (a2-r-1) to (a2-r-7) shown below. Hereinafter, “*” represents a bond.

［式中、Ｒａ’^２１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、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；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、ｎ’は０〜２の整数であり、ｍ’は０または１である。］

[Wherein, Ra ′ ²¹ each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom or an alkyl group; 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, and n ′ is 0 to 2 And m ′ is 0 or 1. ]

In general formulas (a2-r-1) to (a2-r-7), A ″ represents an oxygen atom (—O—) or a sulfur atom (—S—), and may have 1 to 5 carbon atoms. The alkylene group having 1 to 5 carbon atoms in A ″ is preferably a linear or branched alkylene group, a methylene group, an ethylene group, an n-propylene group, An isopropylene group etc. are mentioned. 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. Ra ′ ²¹ independently represents an alkyl group or an alkoxy group. A group, a halogen atom, a halogenated alkyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group.
The alkyl group in ra ^'21, preferably an alkyl group having 1 to 5 carbon atoms.
The alkoxy group in the ra ^'21, preferably an alkoxy group having 1 to 6 carbon atoms.
The alkoxy group is preferably linear or branched. Specifically, groups of the the Ra 'group and an oxygen atom mentioned as the alkyl group in ²¹ (-O-) are linked and the like.
Examples of the halogen atom in Ra ′ ²¹ 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 ^21, the Ra' Ra part or all of the hydrogen atoms of the alkyl group in ²¹ can be mentioned it has been substituted with the aforementioned halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

  Specific examples of groups represented by general formulas (a2-r-1) to (a2-r-7) are given below.

  In the present invention, the structural unit (a2) is preferably a group represented by the general formula (a2-r-1) or (a2-r-2), and the chemical formula (r-lc-1-1) or Groups represented by (r-lc-2-7) are more preferred.

The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —O—C (═O) —O— in the ring skeleton. When the carbonate ring is counted as the first ring, the carbonate ring alone 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.
The carbonate ring-containing cyclic group as the cyclic hydrocarbon group for R ¹ is not particularly limited, and any one can be used. Specific examples include groups represented by the following general formulas (ax3-r-1) to (ax3-r-3).

［式中、Ｒａ’^ｘ３１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、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；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ｑ’は０または１である。］

[ ^Wherein , Ra ′ ^x31 each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom or an alkyl group; 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, and q ′ is 0 or 1. is there. ]

In the general formulas (ax3-r-1) to (ax3-r-3), A ″ is the same as A ″ in the general formula (a2-r-1).
As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in Ra ′ ³¹ , the above general formulas (a2-r-1) to ( a2-r-7) as in the same as those exemplified in the description of the Ra ^'21 of the like.

  Specific examples of groups represented by general formulas (ax3-r-1) to (ax3-r-3) are given below.

  “Heterocyclic group” means a cyclic group containing one or more atoms other than carbon in addition to carbon, and each of the heterocycles listed in (r-hr-1) to (r-hr-16) described later. Examples thereof include a cyclic group and a nitrogen-containing heterocyclic ring. Examples of the nitrogen-containing heterocyclic group include a cycloalkyl group having 3 to 8 carbon atoms which may be substituted with one or two oxo groups. Suitable examples of the cycloalkyl group include 2,5-dioxopyrrolidine and 2,6-dioxopiperidine.

The structural unit (a2) contained in the component (A) may be one type or two or more types.
When the component (A) has the structural unit (a2), the proportion of the structural unit (a2) is preferably 1 to 80 mol% with respect to the total of all the structural units constituting the component (A). It is more preferably 5 to 70 mol%, further preferably 10 to 65 mol%, and particularly preferably 10 to 60 mol%. By making it the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by making it the upper limit value or less, it is possible to balance with other structural units, and various lithography characteristics and patterns Good shape.

  The component (A1) may have the following structural units (a3) and (a4) in addition to the structural units (a1) and (a2).

(Structural unit (a3))
The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (except for those corresponding to the structural units (a1) and (a2) described above).
It is considered that when the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) is increased and the resolution is improved.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group. For example, a resin for a resist composition for an ArF excimer laser can be appropriately selected from those proposed. The cyclic group is preferably a polycyclic group, and more preferably 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

The structural unit (a3) is not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any structural unit can be used.
The structural unit (a3) 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 polar group-containing aliphatic hydrocarbon group A structural unit is preferred.
The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the formula (a3-2), the formula ( The structural unit represented by a3-3) is preferred.

［式中、Ｒは前記と同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。］

[Wherein, R is as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t ′ is an integer of 1 to 3, and l is an integer of 1 to 5] And s is an integer of 1 to 3. ]

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and it is particularly preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group.

In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on the total of all structural units constituting the resin component (A1). Preferably, 5 to 25 mol% is more preferable.
By setting the proportion of the structural unit (a3) to the lower limit value or more, the effect of including the structural unit (a3) can be sufficiently obtained, and by setting the proportion of the structural unit (a3) to the upper limit value or less, balance with other structural units can be obtained. It becomes easy.

(Structural unit (a4))
The structural unit (a4) is a structural unit containing an acid non-dissociable cyclic group. When the component (A1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. Moreover, the hydrophobicity of (A1) component increases. The improvement in hydrophobicity is thought to contribute to the improvement of resolution, resist pattern shape, etc., particularly in the case of organic solvent development.
The “acid non-dissociable cyclic group” in the structural unit (a4) means that when an acid is generated from the later-described component (B) by exposure, it is not dissociated even if the acid acts on the structural unit. The remaining cyclic group.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic cyclic group is preferable. Examples of the cyclic group include those similar to those exemplified for the structural unit (a1), for ArF excimer laser, for KrF excimer laser (preferably for ArF excimer laser), etc. A number of hitherto known materials can be used as the resin component of the resist composition.
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 having the structures of the following general formulas (a4-1) to (a4-7).

［式中、Ｒ^αは、水素原子、メチル基またはトリフルオロメチル基を示す。］

[Wherein, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group. ]

As the structural unit (a4) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1). More preferably, it is 10-20 mol%.

  The component (A1) is preferably a copolymer having (a1) and (a2).

The component (A1) is obtained by polymerizing a monomer that derives each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate. be able to.
Further, for the component (A1), in the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that the terminal 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

  In the present invention, the weight average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, 2000 ˜20,000 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.

As the component (A1), one type may be used alone, or two or more types may be used in combination.
The proportion of the component (A1) in the substrate component (A) is preferably 25% by mass or more, more preferably 50% by mass, further preferably 75% by mass, based on the total mass of the substrate component (A). It may be mass%. When the proportion is 25% by mass or more, the lithography properties are further improved.

In this invention, (A) component may be used individually by 1 type, and may use 2 or more types together.
In the present invention, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<Acid generator component; (B) component>
In the present invention, the resist composition may contain an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as component (B)). 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, and diazomethanes such as poly (bissulfonyl) diazomethanes. Examples include an acid generator, a nitrobenzyl sulfonate acid generator, an imino sulfonate acid generator, and a disulfone acid generator. Of these, it is preferable to use an onium salt acid generator.

  Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as “(b-1) component”) and a general formula (b-2). A compound (hereinafter also referred to as “(b-2) component”) or a compound represented by the general formula (b-3) (hereinafter also referred to as “(b-3) component”) can be used.

［式中、Ｒ^１０１、Ｒ^１０４〜Ｒ^１０８はそれぞれ独立に置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、または置換基を有していてもよい鎖状のアルケニル基である。Ｒ^１０４、Ｒ^１０５は、相互に結合して環を形成していてもよい。Ｒ^１０６〜Ｒ^１０７のいずれか２つは、相互に結合して環を形成していてもよい。Ｒ^１０２は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。Ｙ^１０１は単結合または酸素原子を含む２価の連結基である。Ｖ^１０１〜Ｖ^１０３はそれぞれ独立に単結合、アルキレン基、またはフッ素化アルキレン基である。Ｌ^１０１〜Ｌ^１０２はそれぞれ独立に単結合または酸素原子である。Ｌ^１０３〜Ｌ^１０５はそれぞれ独立に単結合、−ＣＯ−又は−ＳＯ_２−である。Ｍ’^ｍ＋はｍ価の有機カチオンである。］

[Wherein, R ¹⁰¹ and R ^{104 to} R ¹⁰⁸ each independently has a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. A chain alkenyl group which may be present. R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring. Any two of R ^{106 to} R ¹⁰⁷ may be bonded to each other to form a ring. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ^{101 to} V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. L ^{101 to} L ¹⁰² are each independently a single bond or an oxygen atom. L ^{103 to} L ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —. M ′ ^{m +} is an m-valent organic cation. ]

{Anion part}
-Anion moiety of component (b-1) In formula (b-1), R ¹⁰¹ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, Alternatively, a chain alkenyl group which may have a substituent.

(Cyclic group optionally having substituent in R ¹⁰¹ )
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The aromatic hydrocarbon group for R ¹⁰¹ is the aromatic hydrocarbon ring mentioned for the divalent aromatic hydrocarbon group for Va ¹ in the formula (a1-1), or an aromatic compound containing two or more aromatic rings. Examples include an aryl group in which one hydrogen atom is removed, and a phenyl group and a naphthyl group are preferable.
The cyclic aliphatic hydrocarbon group for R ¹⁰¹ is a group obtained by removing one hydrogen atom from the monocycloalkane or polycycloalkane mentioned as the divalent aliphatic hydrocarbon group for Va ¹ in the formula (a1-1). And an adamantyl group and a norbornyl group are preferable.
In addition, the cyclic hydrocarbon group in R ¹⁰¹ may contain a hetero atom such as a heterocycle, and is specifically represented by the general formulas (a2-r-1) to (a2-r-7). Lactone-containing cyclic groups, —SO ₂ -containing cyclic groups represented by the above general formulas (a5-r-1) to (a5-r-4), respectively, and others below (r-hr-1) to And heterocyclic groups listed in (r-hr-16).

Examples of the substituent in the cyclic hydrocarbon group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group.
The alkyl group as a 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 a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more 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 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, a part or all of hydrogen atoms such as an alkyl group having 1 to 5 carbon atoms, for example, methyl group, ethyl group, propyl group, n-butyl group, tert-butyl group, and the like And a group substituted with a halogen atom.

(A chain alkyl group which may have a substituent in R ¹⁰¹ )
The chain alkyl group for R ¹⁰¹ may be either linear or branched.
The linear 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 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.

(Chain-like alkenyl group optionally having substituent in R ¹⁰¹ )
The chain alkenyl group for R ¹⁰¹ may be either linear or branched, preferably has 2 to 10 carbon atoms, more preferably 2 to 5, still more preferably 2 to 4, more preferably 3 Is particularly preferred. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the chain alkenyl group is particularly preferably a propenyl group.

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the cyclic group in R ¹⁰¹ described above. Can be mentioned.

Among these, R ¹⁰¹ is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and lactones represented by the above formulas (a2-r-1) to (a2-r-7), respectively. The containing cyclic group, the —SO ₂ -containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), respectively, and the like are preferable.

In formula (b-1), Y ¹⁰¹ represents a single bond or a divalent linking group containing an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, Y ¹⁰¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen 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 oxycarbonyl group (—O—C (═O). )-), Amide bond (—C (═O) —NH—), carbonyl group (—C (═O) —), carbonate bond (—O—C (═O) —O—), etc. A combination of a non-hydrocarbon oxygen atom-containing linking group and an alkylene group; and the like. A sulfonyl group (—SO ₂ —) may be further linked to the combination. Examples of the combination include linking groups represented by the following formulas (y-al-1) to (y-al-7), respectively.

［式中、Ｖ’^１０１は単結合または炭素数１〜５のアルキレン基であり、Ｖ’^１０２は炭素数１〜３０の２価の飽和炭化水素基である。］

[Wherein, V ′ ¹⁰¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, and V ′ ¹⁰² is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms. ]

The divalent saturated hydrocarbon group for V ′ ¹⁰² is preferably an alkylene group having 1 to 30 carbon atoms.

The alkylene group for V ′ ¹⁰¹ and V ′ ¹⁰² may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferred.
Specific examples of the alkylene group in V ′ ¹⁰¹ and V ′ ¹⁰² 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 Groups [—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 alkyl groups such as, trimethylene group (n- propylene _{group) [- CH 2 CH 2 CH} 2 -]; - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH ₂ - and the like alkyl trimethylene group; tetramethylene _{[-CH 2 CH 2 CH 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.
Moreover, some methylene groups in the alkylene group in V ′ ¹⁰¹ or V ′ ¹⁰² may be substituted with a C 5-10 divalent aliphatic cyclic group. The aliphatic cyclic group is preferably a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group of Ra ′ ^{3 in} the formula (a1-r-1). 1,5-adamantylene group or 2,6-adamantylene group is more preferable.

Y ¹⁰¹ is preferably a divalent linking group containing an ester bond or an ether bond, and linking groups represented by the above formulas (y-al-1) to (y-al-5) are preferred.

In formula (b-1), V ¹⁰¹ represents a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group for V ¹⁰¹ preferably have 1 to 4 carbon atoms. ^Examples of the fluorinated alkylene group for V ¹⁰¹ include groups in which some or all of the hydrogen atoms of the alkylene group for V ¹⁰¹ have been substituted with fluorine atoms. Among ^{them, V 101} is preferably a single bond, or a fluorinated alkylene group having 1 to 4 carbon atoms.

In formula (b-1), R ¹⁰² represents a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R ¹⁰² is preferably a fluorine atom or a C 1-5 perfluoroalkyl group, and more preferably a fluorine atom.

(B-1) Specific examples of the anion moiety of the component, for example, if the Y ¹⁰¹ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethane sulfonate anion or perfluorobutane sulfonate anion can be exemplified; Y ¹⁰¹ is In the case of a divalent linking group containing an oxygen atom, anions represented by any one of the following formulas (an-1) to (an-3) can be mentioned.

［式中、Ｒ”^１０１は、置換基を有していてもよい脂肪族環式基、前記式（ｒ−ｈｒ−１）〜（ｒ−ｈｒ−６）でそれぞれ表される基、又は置換基を有していてもよい鎖状のアルキル基であり；Ｒ”^１０２は、置換基を有していてもよい脂肪族環式基、前記式（ａ２−ｒ−１）〜（ａ２−ｒ−７）でそれぞれ表されるラクトン含有環式基、又は前記一般式（ａ５−ｒ−１）〜（ａ５−ｒ−４）でそれぞれ表される−ＳＯ_２−含有環式基であり；Ｒ”^１０３は、置換基を有していてもよい芳香族環式基、置換基を有していてもよい脂肪族環式基、又は置換基を有していてもよい鎖状のアルケニル基であり；Ｖ”^１０１は、フッ素化アルキレン基であり；Ｌ”^１０１は、−Ｃ（＝Ｏ）−又は−ＳＯ_２−であり；ｖ”はそれぞれ独立に０〜３の整数であり、ｑ”はそれぞれ独立に１〜２０の整数であり、ｎ”は０または１である。］

[Wherein R ″ ¹⁰¹ represents an aliphatic cyclic group which may have a substituent, a group represented by each of the above formulas (r-hr-1) to (r-hr-6), or a substituent. A chain-like alkyl group which may have a group; R ″ ¹⁰² represents an aliphatic cyclic group which may have a substituent, the above formulas (a2-r-1) to (a2-r); lactone-containing cyclic group represented respectively by -7), or the formula (a5-r-1) ~ (a5-r-4) with -SO ₂ respectively represented - be-containing cyclic group; R ¹⁰³ is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. ^{There; V "101} is an fluorinated alkylene ^{group; L" 101} is, -C (= O) - or -SO ₂ - a and; v "0 to 3 are each independently Is an integer, q "are each independently an integer of 1 to 20, n" is 0 or 1. ]

The aliphatic cyclic group which may have a substituent of R ″ ¹⁰¹ , R ″ ¹⁰² and R ″ ¹⁰³ is preferably the group exemplified as the cyclic aliphatic hydrocarbon group in R ¹⁰¹ . Examples of the substituent include the same substituents that may be substituted for the cyclic aliphatic hydrocarbon group in R ¹⁰¹ .

The aromatic cyclic group which may have a substituent in R ″ ¹⁰³ is preferably the group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in R ¹⁰¹ . , R ¹⁰¹ and the same substituents that may be substituted for the aromatic hydrocarbon group.

The chain alkyl group which may have a substituent in R ″ ¹⁰¹ is preferably the group exemplified as the chain alkyl group in R ^101. The chain in R ″ ¹⁰³ has a substituent. The good chain alkenyl group is preferably the group exemplified as the chain alkenyl group in R ¹⁰¹ . V ″ ¹⁰¹ is preferably a fluorinated alkylene group having 1 to 3 carbon atoms, and particularly preferably —CF ₂ —, —CF ₂ CF ₂ —, —CHFCF ₂ —, —CF (CF ₃ ) CF ₂ —. , —CH (CF ₃ ) CF ₂ —.

-Anion part of component (b-2) In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ may each independently have a cyclic group which may have a substituent or a substituent. Examples thereof include a good chain alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include the same as those described above for R ¹⁰¹ in formula (b-1). However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably a chain alkyl group which may have a substituent, and are a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. It is more preferable.
The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms. The carbon number of the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible for reasons such as good solubility in a resist solvent within the above carbon number range. In addition, in the chain alkyl group of R ¹⁰⁴ and R ^105, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and against high-energy light and electron beams of 200 nm or less Since transparency improves, it is preferable. The proportion of fluorine atoms in the chain alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. Perfluoroalkyl group.
In formula (b-2), V ¹⁰² and V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each of them is the same as V ¹⁰¹ in formula (b-1). Can be mentioned.
In formula (b-2), L ^{101 to} L ¹⁰² each independently represents a single bond or an oxygen atom.

-Anion part of (b-3) component In formula (b-3), R < ¹⁰⁶ > -R < ¹⁰⁸ > may have the cyclic group which may have a substituent, and a substituent each independently. Examples thereof include a good chain alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include the same as those described above for R ¹⁰¹ in formula (b-1).
L ^{103 to} L ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —.

{Cation part}
In formulas (b-1), (b-2) and (b-3), M ′ ^{m +} is an m-valent organic cation, preferably a sulfonium cation or an iodonium cation. The cations represented by (ca-1) to (ca-4) are particularly preferred.

［式中、Ｒ^２０１〜Ｒ^２０７、およびＲ^２１１〜Ｒ^２１２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、Ｒ^２０１〜Ｒ^２０３、Ｒ^２０６〜Ｒ^２０７、Ｒ^２１１〜Ｒ^２１２は、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。Ｒ^２０８〜Ｒ^２０９はそれぞれ独立に水素原子または炭素数１〜５のアルキル基を表し、Ｒ^２１０は置換基を有していてもよいアリール基、アルキル基、アルケニル基、又は−ＳＯ_２−含有環式基であり、Ｌ^２０１は−Ｃ（＝Ｏ）−または−Ｃ（＝Ｏ）−Ｏ−を表し、Ｙ^２０１は、それぞれ独立に、アリーレン基、アルキレン基またはアルケニレン基を表し、ｘは１または２であり、Ｗ^２０１は（ｘ＋１）価の連結基を表す。］

[Wherein, R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, and R ^{201 to} R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ and R ^{211 to} R ²¹² may be bonded to each other to form a ring together with the sulfur atom in the formula. R ^{208 to} R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ²¹⁰ is an aryl group, alkyl group, alkenyl group, or —SO ₂ — containing an optionally substituted substituent. A cyclic group, L ²⁰¹ represents —C (═O) — or —C (═O) —O—, Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group, and x represents 1 or 2 and W ²⁰¹ represents a (x + 1) -valent linking group. ]

Examples of the aryl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.
The alkyl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² is a chain or cyclic alkyl group and preferably has 1 to 30 carbon atoms.
The alkenyl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² preferably has 2 to 10 carbon atoms.
Examples of the substituent that R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and an arylthio group. And groups represented by the following formulas (ca-r-1) to (ca-r-7).
The aryl group in the arylthio group as a substituent is the same as that described for R ¹⁰¹ , and specifically includes a phenylthio group or a biphenylthio group.

［式中、Ｒ’^２０１はそれぞれ独立に、水素原子、置換基を有していてもよい環式基、鎖状のアルキル基、または鎖状のアルケニル基である。］

[Wherein, R ′ ²⁰¹ each independently represents a hydrogen atom, an optionally substituted cyclic group, a chain alkyl group, or a chain alkenyl group. ]

The cyclic group which may have a substituent of R ′ ^201, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent are as described above. In addition to the same groups as those described above for R ^{101 in} formula (b-1), a cyclic group which may have a substituent or a chain alkyl group which may have a substituent may have the above formula ( Examples thereof include the same acid dissociable groups represented by a1-r-2).

^{R 201 ~R 203, R 206 ~R} 207, R 211 ~R 212 , when bonded to each other to form a ring with the sulfur atom, a sulfur atom, an oxygen atom, or a hetero atom such as nitrogen atom, carbonyl _{group, -SO -, - SO 2 -} , - SO 3 -, - COO -, - CONH- , or -N _(R N) - (. the _{R N} is an alkyl group having 1 to 5 carbon atoms), etc. You may couple | bond through the functional group of. 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. 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.

R ^{208 to} R ²⁰⁹ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when formed into an alkyl group, they are bonded to each other to form a ring. May be formed.

R ²¹⁰ may have an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. -SO ₂ - containing cyclic group.
The aryl group in R ^210, include unsubstituted aryl group having 6 to 20 carbon atoms, a phenyl group, a naphthyl group.
The alkyl group for R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group for R ²¹⁰ preferably has 2 to 10 carbon atoms.
The —SO ₂ — containing cyclic group which may have a substituent in R ²¹⁰ is the same as the “—SO ₂ — containing cyclic group” of Ra ^{21 in} the general formula (a2-1). The group represented by the general formula (a5-r-1) is preferable.

Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group.
Examples of the arylene group for Y ²⁰¹ include a group in which one hydrogen atom has been removed from the aryl group exemplified as the aromatic hydrocarbon group for R ¹⁰¹ in the above formula (b-1).
Examples of the alkylene group and alkenylene group for Y ²⁰¹ include the same aliphatic hydrocarbon groups as the divalent hydrocarbon group for Va ¹ in the general formula (a1-1).

In the formula (ca-4), x is 1 or 2.
W ²⁰¹ is a (x + 1) valent, that is, a divalent or trivalent linking group.
The divalent linking group in W ²⁰¹ is preferably a divalent hydrocarbon group which may have a substituent, and examples thereof include the same hydrocarbon groups as Ya ²¹ in the general formula (a2-1). The divalent linking group in W ²⁰¹ may be linear, branched or cyclic, and is preferably cyclic. 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 ²⁰¹ include a group obtained by removing one hydrogen atom from the divalent linking group in W ²⁰¹ , a group in which the divalent linking group is further bonded to the divalent linking group, and the like. Can be mentioned. The trivalent linking group in W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

  Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following formulas (ca-1-1) to (ca-1-63), respectively.

［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. ]

［式中、Ｒ”^２０１は水素原子又は置換基であって、置換基としては前記Ｒ^２０１〜Ｒ^２０７、およびＲ^２１０〜Ｒ^２１２が有していてもよい置換基として挙げたものと同様である。］

[Wherein R ″ ²⁰¹ is a hydrogen atom or a substituent, and the substituent is the same as the substituents that R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have. is there.]

  Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

  Specific examples of suitable cations represented by the formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2).

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.
In this invention, when a resist composition contains (B) component, 0.5-60 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for content of (B) component, 1-50 mass parts Is more preferable, and 1-40 mass parts is further more preferable. By forming the content of the component (B) 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.

<Basic compound component; (D) component>
In the present invention, the resist composition contains an acid diffusion controller component (hereinafter also referred to as “component (D)”) in addition to the component (A) or in addition to the components (A) and (B). You may contain.
The component (D) acts as a quencher (acid diffusion controller) that traps acid generated by exposure from the component (B) and the like.
The component (D) in the present invention may be a photodegradable base (D1) (hereinafter referred to as “(D1) component”) that is decomposed by exposure and loses acid diffusion controllability. A non-corresponding nitrogen-containing organic compound (D2) (hereinafter referred to as “component (D2)”) may be used.

[(D1) component]
By forming the resist composition containing the component (D1), the contrast between the exposed portion and the non-exposed portion can be improved when forming a resist pattern.
The component (D1) is not particularly limited as long as it is decomposed by exposure and loses acid diffusion controllability, and is a compound represented by the following general formula (d1-1) (hereinafter referred to as “(d1-1) component”). ), A compound represented by the following general formula (d1-2) (hereinafter referred to as “(d1-2) component”) and a compound represented by the following general formula (d1-3) (hereinafter referred to as “(d1- One or more compounds selected from the group consisting of “3) component”) are preferred.
The components (d1-1) to (d1-3) are decomposed in the exposed portion and lose acid diffusion controllability (basicity), and thus do not act as a quencher, and act as a quencher in an unexposed portion.

［式中、Ｒｄ^１〜Ｒｄ^４は置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、または置換基を有していてもよい鎖状のアルケニル基である。ただし、式（ｄ１−２）中のＲｄ^２における、Ｓ原子に隣接する炭素原子には２つ以上のフッ素原子は結合していないものとする。Ｙｄ^１は単結合、または２価の連結基である。Ｍ^ｍ＋はそれぞれ独立にｍ価の有機カチオンである。］

[Wherein Rd ^{1 to} Rd ⁴ are a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain which may have a substituent. Of the alkenyl group. However, it is assumed that two or more fluorine atoms are not bonded to the carbon atom adjacent to the S atom in Rd ² in the formula (d1-2). Yd ¹ is a single bond or a divalent linking group. M ^{m +} is each independently an m-valent organic cation. ]

{(D1-1) component}
During Anion formula (d1-1), Rd ¹ is have an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, Or a similar chain alkenyl group to the same as R ¹⁰¹ .
Among these, Rd ¹ may have an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. A chain hydrocarbon group is preferred. The substituent that these groups may have is preferably a hydroxyl group, a fluorine atom or a fluorinated alkyl group.
The aromatic hydrocarbon group is more preferably a phenyl group or a naphthyl group.
The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane.
As the chain hydrocarbon group, a chain alkyl group is preferable. The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a nonyl group. A linear alkyl group such as a group or decyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group And branched chain alkyl groups such as 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, and the like.

When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the fluorinated alkyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 8 carbon atoms. The fluorinated alkyl group, which is more preferably ˜4, may contain an atom other than a fluorine atom. Examples of atoms other than fluorine atoms include oxygen atoms, carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms.
Rd ¹ is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted by fluorine atoms, and the hydrogen atom constituting the linear alkyl group It is preferable that all are fluorinated alkyl groups (linear perfluoroalkyl groups) substituted with fluorine atoms.

  Preferred specific examples of the anion moiety of the component (d1-1) are shown below.

-Cation part In formula (d1-1), Mm ⁺ is an m-valent organic cation.
The organic cation of M ^{m +} is not particularly limited, and examples thereof include those similar to the cations represented by the general formulas (ca-1) to (ca-4), respectively, and the formula (ca-1- Cations represented by 1) to (ca-1-63) are preferable.
As the component (d1-1), one type may be used alone, or two or more types may be used in combination.

{(D1-2) component}
· During anion formula (d1-2), Rd ² is has an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, A chain alkenyl group which may be the same as R ¹⁰¹ .
However, it is assumed that two or more fluorine atoms are not bonded to the carbon atom adjacent to the S atom in Rd ² (not fluorine-substituted). Thereby, the anion of (d1-2) component turns into a moderate weak acid anion, and the quenching ability of (D) component improves.
Rd ² is preferably an aliphatic cyclic group which may have a substituent, and a group in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane or the like. (It may have a substituent); it is more preferably a group obtained by removing one or more hydrogen atoms from camphor or the like.
The hydrocarbon group of Rd ² may have a substituent, and examples of the substituent include a hydrocarbon group (aromatic hydrocarbon group, aliphatic hydrocarbon group) in Rd ¹ of the formula (d1-1). The same thing as the substituent which may have is mentioned.

  Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

-Cation part In formula (d1-2), Mm ⁺ is an m-valent organic cation, and is the same as Mm ⁺ in formula (d1-1).
As the component (d1-2), one type may be used alone, or two or more types may be used in combination.

{(D1-3) component}
During Anion formula (d1-3), Rd ³ is have an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, A chain alkenyl group that may be the same as R ^101, and is preferably a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group. Among them, a fluorinated alkyl group is preferable, and the same as the fluorinated alkyl group for Rd ¹ is more preferable.

In formula (d1-3), Rd ⁴ may have a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. Examples of the chain alkenyl group include those similar to R ¹⁰¹ .
Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group which may have a substituent is preferable.
The alkyl group in Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group. Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A part of the hydrogen atoms of the alkyl group of Rd ⁴ may be substituted with a hydroxyl group, a cyano group, or the like.
The alkoxy group in Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms. Specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n- Examples include butoxy group and tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferable.

Examples of the alkenyl group in Rd ⁴ include those similar to R ¹⁰¹ described above, and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group are preferable. These groups may further have, as a substituent, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

Examples of the cyclic group for Rd ⁴ include the same groups as those described above for R ^101, and one or more hydrogen atoms are removed from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group or an aromatic group such as a phenyl group or a naphthyl group is preferred. When Rd ⁴ is an alicyclic group, the resist composition is well dissolved in an organic solvent, whereby the lithography properties are improved. In addition, when Rd ⁴ is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition is excellent in light absorption efficiency, and sensitivity and lithography characteristics are good.

In formula (d1-3), Yd ¹ represents a single bond or a divalent linking group.
The divalent linking group in Yd ¹ is not particularly limited, but may be a divalent hydrocarbon group (aliphatic hydrocarbon group or aromatic hydrocarbon group) which may have a substituent, or a hetero atom containing 2 Valent linking groups and the like. These may be the same as those exemplified in the description of the divalent linking group of Ya ²¹ in the formula (a2-1).
Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is preferably a linear or branched alkylene group, and more preferably a methylene group or an ethylene group.

  Preferred specific examples of the anion moiety of the component (d1-3) are shown below.

-Cation part In formula (d1-3), Mm ⁺ is an m-valent organic cation, and is the same as Mm ⁺ in formula (d1-1).
As the component (d1-3), one type may be used alone, or two or more types may be used in combination.

As the component (D1), only one of the above components (d1-1) to (d1-3) may be used, or two or more may be used in combination.
The content of the component (D1) is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, with respect to 100 parts by mass of the component (A). More preferably, it is part by mass.
When the content of the component (D1) is not less than the preferable lower limit value, particularly good lithography characteristics and a resist pattern shape are obtained. On the other hand, when it is not more than the upper limit value, the sensitivity can be maintained well and the throughput is also excellent.

  The manufacturing method of said (d1-1) component and (d1-2) component is not specifically limited, It can manufacture by a well-known method.

  The content of the component (D1) is preferably 0.5 to 10.0 parts by mass and more preferably 0.5 to 8.0 parts by mass with respect to 100 parts by mass of the component (A). 1.0 to 8.0 parts by mass is even more preferable. When it is at least the lower limit of the above range, particularly good lithography properties and resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

((D2) component)
(D) component may contain the nitrogen-containing organic compound component (henceforth (D2) component) which does not correspond to the said (D1) component.
The component (D2) is not particularly limited as long as it functions as an acid diffusion control agent and does not correspond to the component (D1), and any known component may be used. Of these, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred.
An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, Li isopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

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-hydroxy Ethoxy) ethoxy} ethyl] amine, triethanolamine triacetate and the like, and triethanolamine triacetate is preferable.

As the component (D2), an aromatic amine may be used.
Aromatic amines include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxy. And carbonylpyrrolidine.

(D2) A component may be used independently and may be used in combination of 2 or more type.
(D2) A 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.

(D) A component may be used individually by 1 type and may be used in combination of 2 or more type.
In this invention, when a resist composition contains (D) component, it is preferable that (D) component is 0.1-15 mass parts with respect to 100 mass parts of (A) component, 0.3- More preferably, it is 12 mass parts, and it is still more preferable that it is 0.5-12 mass parts. When it is at least the lower limit of the above range, lithography properties such as LWR are further improved when a resist composition is used. Further, a better resist pattern shape can be obtained. When it is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

<Optional component>
[(E) component]
In the present invention, the resist composition includes organic carboxylic acid, phosphorus oxo acid and derivatives thereof as optional components for the purpose of preventing sensitivity deterioration and improving the resist pattern shape and stability with time. At least one compound (E) selected from the group (hereinafter referred to as component (E)) can be contained.
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 phosphinic acid esters and phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
(E) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

[(F) component]
In the present invention, the resist composition may contain a fluorine additive (hereinafter referred to as “component (F)”) in order to impart water repellency to the resist film.
Examples of the component (F) include JP 2010-002870 A, JP 2010-032994 A, JP 2010-277043 A, JP 2011-13569 A, and JP 2011-128226 A. The described fluorine-containing polymer compound can be used.
More specifically, examples of the component (F) include a polymer having a structural unit (f1) represented by the following formula (f1-1). As the polymer, a polymer (homopolymer) consisting only of the structural unit (f1) represented by the following formula (f1-1); a structural unit (f1) represented by the following formula (f1-1); A copolymer with the structural unit (a1); a structural unit (f1) represented by the following formula (f1-1); a structural unit derived from acrylic acid or methacrylic acid; and the structural unit (a1) It is preferable that it is a copolymer. Here, as the structural unit (a1) copolymerized with the structural unit (f1) represented by the following formula (f1-1), 1-ethyl-1-cyclooctyl (meth) acrylate or the formula (a1) -2-01) is preferred.

［式中、Ｒは前記同様であり、Ｒｆ^１０２およびＲｆ^１０３はそれぞれ独立して水素原子、ハロゲン原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基を表し、Ｒｆ^１０２およびＲｆ^１０３は同じであっても異なっていてもよい。ｎｆ^１は１〜５の整数であり、Ｒｆ^１０１はフッ素原子を含む有機基である。］

[Wherein, R is the same as defined above, and Rf ¹⁰² and Rf ¹⁰³ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, Rf ¹⁰² and Rf ¹⁰³ may be the same or different. nf ¹ is an integer of ¹ to 5, and Rf ¹⁰¹ is an organic group containing a fluorine atom. ]

In formula (f1-1), R is the same as described above. R is preferably a hydrogen atom or a methyl group.
In formula (f1-1), examples of the halogen atom for Rf ¹⁰² and Rf ¹⁰³ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. Examples of the alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ 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. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ include a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with a halogen atom. Can be mentioned. 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. The inter alia ^{Rf 102} and ^{Rf 103,} a hydrogen atom, a fluorine atom, or an alkyl group of 1 to 5 carbon atoms is preferable, a hydrogen atom, a fluorine atom, a methyl group or an ethyl group, preferred.
In formula (f1-1), nf ¹ is an integer of ¹ to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

In formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms. The carbon number of 1 to 10 is particularly preferable.
The hydrocarbon group containing a fluorine atom preferably has 25% or more of the hydrogen atoms in the hydrocarbon group fluorinated, more preferably 50% or more fluorinated, and 60% or more. Fluorination is particularly preferable because the hydrophobicity of the resist film during immersion exposure is increased.
Among ^these, as ^{Rf 101,} particularly preferably a fluorinated hydrocarbon group having 1 to 5 carbon atoms, a methyl _{group, -CH 2 -CF 3, -CH 2} -CF 2 -CF 3, -CH (CF 3) 2 _{, -CH} 2 _-CH 2 _-CF 3, and most preferably _{-CH 2 -CH 2 -CF 2 -CF 2} -CF 2 -CF 3.

(F) As for the weight average molecular weight (Mw) (polystyrene conversion reference | standard by a gel permeation chromatography), 1000-50000 are preferable, 5000-40000 are more preferable, and 10000-30000 are the most preferable. 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) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

(F) A component may be used individually by 1 type and may use 2 or more types together.
(F) A component is normally used in the ratio of 0.5-10 mass parts with respect to 100 mass parts of (A) component.

  In the present invention, the resist composition further contains an optional miscible additive, for example, an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, and an antihalation agent. A dye or the like can be added and contained as appropriate.

[(S) component]
In the present invention, the resist composition can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone (2-heptanone), methyl isopentyl ketone; ethylene glycol, diethylene glycol, propylene glycol, di- Polyhydric alcohols such as propylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, the polyhydric alcohols or compounds having the ester bond Monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having an ether bond such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) among these; cyclic ethers such as dioxane, , Methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, etc .; anisole, ethyl benzyl ether, cresyl methyl Ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene And aromatic organic solvents such as dimethyl sulfoxide (DMSO).
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Of these, PGMEA, PGME, γ-butyrolactone, and EL are 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.
More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA: EL or cyclohexanone 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.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
(S) The usage-amount of a component is not specifically limited, It is a density | concentration which can be apply | coated to a board | substrate etc., and is suitably set according to a coating film thickness. Generally, it is used so that the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

[Step B]
In step B, a solution containing an acid or thermal acid generator is applied so as to cover the first resist pattern to form a first layer. In step B, as shown in FIG. 1B, the first layer 2 is formed so as to cover the first resist pattern 1P formed in step A.
In step B, a solution containing an acid or a thermal acid generator is applied, and the formed first layer acts on the pattern surface of the first resist pattern. In step C, the first resist pattern is formed. The solubility of the pattern surface in the developer can be changed.

[Solution containing acid or thermal acid generator]
In the present invention, a solution containing an acid or a thermal acid generator will be described. The solution containing an acid or thermal acid generator is preferably composed of an acid or thermal acid generator, a polymer compound, and a solvent.

[Acid (acid component (T0))]
In the present invention, the “acid” itself is acidic and acts as a proton donor (hereinafter sometimes referred to as “acid component (T0)”). Examples of such a (T0) component include nonionic acids that do not form a salt.
Examples of the (T0) component include acid components such as fluorinated alkyl group-containing carboxylic acids, higher fatty acids, higher alkyl sulfonic acids, higher alkyl aryl sulfonic acids, and camphor sulfonic acids.

Examples of the fluorinated alkyl group-containing carboxylic acid include C ₁₀ F ₂₁ COOH.
Examples of higher fatty acids include higher fatty acids having an alkyl group having 8 to 20 carbon atoms, and specific examples include dodecanoic acid, tetradecanoic acid, and stearic acid.
The alkyl group having 8 to 20 carbon atoms may be linear or branched, and a phenylene group or an oxygen atom may be interposed in the chain, or hydrogen in the alkyl group. A part of the atoms may be substituted with a hydroxyl group or a carboxy group.
Examples of the higher alkyl sulfonic acid include sulfonic acids having an alkyl group with an average carbon number of preferably 9 to 21, more preferably 12 to 18. Specifically, decane sulfonic acid, dodecane sulfonic acid, and tetradecane sulfonic acid. , Pentadecane sulfonic acid, stearic acid sulfonic acid and the like.
Examples of the higher alkylaryl sulfonic acid include alkylbenzene sulfonic acid and alkyl naphthalene sulfonic acid having an alkyl group with an average carbon number of preferably 6 to 18, more preferably 9 to 15, and specifically, dodecylbenzene sulfone. Examples include acid and decylnaphthalenesulfonic acid.

  Other acid components include alkyl diphenyl ether disulfonic acid having an alkyl group with an average carbon number of preferably 6 to 18, more preferably 9 to 15, and specifically, dodecyl diphenyl ether disulfonic acid and the like.

[Thermal acid generator (acid component (T1))]
The thermal acid generator (hereinafter sometimes referred to as “acid component (T1)”) is a component that generates an acid by heating. As thermal acid generator components that generate acid by heating, onium salt acid generators such as iodonium salts and sulfonium salts; oxime sulfonate acid generators; bisalkyl or bisarylsulfonyldiazomethanes; poly (bis There are various known diazomethane acid generators such as sulfonyl) diazomethanes; nitrobenzyl sulfonate acid generators; imino sulfonate acid generators; disulfone acid generators. These acid generator components are also known as photoacid generators, but also function as thermal acid generators. Accordingly, as the acid generator component that can be used in the present invention, any conventionally known acid generator for chemically amplified resist compositions can be used.
Especially, as an acid component (T1), what is represented by either of the following general formula (T1-1)-(T1-3) is preferable.

［式中、Ｒｔ^１０１、Ｒｔ^１０４〜Ｒｔ^１０８はそれぞれ独立に置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、または置換基を有していてもよい鎖状のアルケニル基である。Ｒｔ^１０４、Ｒｔ^１０５は、相互に結合して環を形成していてもよい。Ｒｔ^１０６〜Ｒｔ^１０７のいずれか２つは、相互に結合して環を形成していてもよい。Ｒｔ^１０２は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。Ｙｔ^１０１は単結合または酸素原子を含む２価の連結基である。Ｖｔ^１０１〜Ｖｔ^１０３はそれぞれ独立に単結合、アルキレン基、またはフッ素化アルキレン基である。Ｌｔ^１０１〜Ｌｔ^１０２はそれぞれ独立に単結合または酸素原子である。Ｌｔ^１０３〜Ｌｔ^１０５はそれぞれ独立に単結合、−ＣＯ−又は−ＳＯ_２−である。Ｒｔ^３０１〜Ｒｔ^３０４は、それぞれ独立に、水素原子又は炭素数１〜１２の直鎖状、分岐鎖状又は環状のフッ素化アルキル基である。Ｒｔ^３０１〜Ｒｔ^３０３は、相互に結合して式中の窒素原子と共に環を形成していてもよい。］

[Wherein, Rt ¹⁰¹ and Rt ^{104 to} Rt ¹⁰⁸ each independently have a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. A chain alkenyl group which may be present. Rt ¹⁰⁴ and Rt ¹⁰⁵ may be bonded to each other to form a ring. Any two of Rt ^{106 to} Rt ¹⁰⁷ may be bonded to each other to form a ring. Rt ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Yt ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. Vt ^{101 to} Vt ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. Lt ^{101 to} Lt ¹⁰² are each independently a single bond or an oxygen atom. Lt ^{103 to} Lt ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —. Rt ^{301 to} Rt ³⁰⁴ are each independently a hydrogen atom or a linear, branched or cyclic fluorinated alkyl group having 1 to 12 carbon atoms. Rt ^{301 to} Rt ³⁰³ may be bonded to each other to form a ring together with the nitrogen atom in the formula. ]

{Anion part}
-Anion part of (T1-1) component In formula (T1-1), Rt ¹⁰¹ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, Alternatively, a chain alkenyl group which may have a substituent.
In the formula (T1-1), the description of Rt ^{101 is the same} as the description of R ¹⁰¹ in the formula (b-1).

In formula (T1-1), Yt ¹⁰¹ represents a single bond or a divalent linking group containing an oxygen atom.
The description of Yt ¹⁰¹ in the formula (T1-1) is the same as the description of Y ¹⁰¹ in the above formula (b-1).

In formula (T1-1), Vt ¹⁰¹ represents a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group in Vt ¹⁰¹ preferably have 1 to 4 carbon atoms. As the fluorinated alkylene group for Vt ^101, some or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms in the vt ^101. Among these, Vt ¹⁰¹ is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

In formula (T1-1), Rt ¹⁰² represents a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Rt ¹⁰² is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

Specific examples of the anion part of (T1-1) component, for example, if Yt ¹⁰¹ is a single bond, include fluorinated alkyl sulfonate anions such as trifluoromethane sulfonate anion or perfluorobutane sulfonate anion; Yt ¹⁰¹ is In the case of a divalent linking group containing an oxygen atom, anions represented by any of the above formulas (an-1) to (an-3) can be mentioned.

-Anion moiety of component (T1-2) In formula (T1-2), Rt ¹⁰⁴ and Rt ¹⁰⁵ may each independently have a cyclic group which may have a substituent or a substituent. Examples thereof include a good chain alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include the same as those described above for Rt ¹⁰¹ in formula (T1-1). However, Rt ¹⁰⁴ and Rt ¹⁰⁵ may be bonded to each other to form a ring.
Rt ¹⁰⁴ and Rt ¹⁰⁵ are preferably a chain alkyl group which may have a substituent, and are a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. It is more preferable.
The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms. The number of carbon atoms of the chain alkyl group of Rt ¹⁰⁴ and Rt ¹⁰⁵ is preferably as small as possible for reasons such as good solubility in a resist solvent within the above carbon number range. In addition, in the chain alkyl group of Rt ¹⁰⁴ and Rt ^105, the greater the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid strength, and against high-energy light and electron beams of 200 nm or less Since transparency improves, it is preferable. The proportion of fluorine atoms in the chain alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. Perfluoroalkyl group.
In formula (T1-2), Vt ¹⁰² and Vt ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each of them is the same as Vt ¹⁰¹ in formula (T1-1). Can be mentioned.
In formula (T1-2), Lt ^{101 to} Lt ¹⁰² each independently represents a single bond or an oxygen atom.

During · (T1-3) component of Anion formula ^(T1-3), Rt 106 ~Rt ¹⁰⁸ are each independently optionally substituted cyclic group, which may have a substituent Examples thereof include a good chain alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include the same as those described above for Rt ¹⁰¹ in formula (T1-1).
Lt ^{103 to} Lt ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —.

{Cation part}
In the cation moieties of the general formulas (T1-1) to (T1-3), Rt ^{301 to} Rt ³⁰⁴ are each independently a hydrogen atom or a linear, branched or cyclic fluorinated group having 1 to 12 carbon atoms. It is an alkyl group. Rt ^{301 to} Rt ³⁰³ may be bonded to each other to form a ring together with the nitrogen atom in the formula. As the ring to be formed, one ring containing a nitrogen 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 nitrogen atom. preferable. Specific examples of the ring to be formed include a pyridine ring. Hereinafter, preferred specific examples of the cation moiety of the general formulas (T1-1) to (T1-3) are listed.

  As a suitable thing of an acid component (T1), the compound represented by the said general formula (T1-1) is preferable, and as an anion part of the compound represented by the said general formula (T1-1), the said formula ( an anion portion represented by an-1) is preferred.

  In the present invention, the acid component (T1) is preferably a compound (T1) -1 shown below.

The acid component (T0) or (T1) described above may be used alone or in combination of two or more in the solution containing the acid or thermal acid generator.
In the present invention, in the solution containing the acid or thermal acid generator, the content of the acid component (T0) or (T1) is such that the solid content concentration of the solution containing the acid or thermal acid generator is 0.1 to 5 parts by mass. Preferably, 0.15-3 mass parts is more preferable, and 0.15-1.5 mass parts is further more preferable.

[Polymer compound (Tp)]
In the present invention, a polymer compound that is preferably contained in a solution containing an acid or a thermal acid generator will be described. A polymer compound that is preferably contained in a solution containing an acid or a thermal acid generator may be referred to as “polymer compound (Tp)”. The polymer compound (Tp) is a polymer compound that improves the coating property of a solution containing an acid or a thermal acid generator and can be removed by organic solvent development in step D described later, that is, is dissolved in an organic solvent. If it does not specifically limit.
In the present invention, the polymer compound (Tp) preferably includes a structural unit having a hydrocarbon group which may have a substituent. As a structural unit which has the hydrocarbon group which may have a substituent, the structural unit represented by the following general formula (Tp) -1 is mentioned, for example.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｒｔｐは置換基を有していてもよい炭化水素基である。ｎ_ｔｐは０又は１である。また、ｎ_ｔｐが０のとき、Ｒｔｐは水酸基であってもよい。］

[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, and Rtp represents a hydrocarbon group which may have a substituent. n _tp is 0 or 1. When n _tp is 0, Rtp may be a hydroxyl group. ]

In the general formula (Tp) -1, 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, Similarly, in formula (Tp) -1, R is preferably a hydrogen atom or a methyl group.
In general formula (Tp) -1, Rtp is a hydrocarbon group which may have a substituent.

The hydrocarbon group in Rtp is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms; a linear or branched alkyl group is preferable, and specifically, methyl Group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, 1,1-dimethylethyl group, 1,1-diethylpropyl group, 2 , 2-dimethylpropyl group, 2,2, -dimethylbutyl group and the like.
When Rtp is a cyclic hydrocarbon group, it may be aliphatic or aromatic, may be polycyclic, or may be monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane and cyclooctane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

When Rtp is an aromatic hydrocarbon group, specific examples of the aromatic ring contained include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; carbon constituting the aromatic hydrocarbon ring An aromatic heterocyclic ring in which a part of the atoms is substituted with a hetero atom; 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 one hydrogen atom from the aromatic hydrocarbon ring (aryl group); a group in which one of the hydrogen atoms of the aryl group is substituted with an alkylene group (for example, Benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl 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.

Rtp may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl 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.
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 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 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.
In the cyclic aliphatic hydrocarbon group, a part of carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing the hetero atom, —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, and —S (═O) ₂ —O— are preferable.
When n _tp is 0, Rtp may be a hydroxyl group.

The structural unit represented by the general formula (Tp) -1 is derived from a structural unit ((Tp) -1-1) containing a polar group-containing aliphatic hydrocarbon group having a polar group as a substituent, and hydroxystyrene. Structural unit ((Tp) -1-2), structural unit derived from styrene ((Tp) -1-3), structural unit containing a linear or cyclic aliphatic hydrocarbon group ((Tp) -1 -4) and a structural unit derived from vinyl alcohol ((Tp) -1-5) are preferable.
In the present invention, the structural unit (Tp) -1-1 is preferably the structural unit (a3) containing the above-mentioned polar group-containing aliphatic hydrocarbon group, and among them, the general formula (a3-1) or (a3) The structural unit represented by -3) is preferable.
As the structural unit (Tp) -1-2, structural units represented by general formula (Tp) -1-2-1 shown below can be mentioned. Examples of the structural unit (Tp) -1-3 include structural units represented by the following general formula (Tp) -1-3-1.

（式中、Ｒ^ｓｔは水素原子またはメチル基を表し、ｍ_０１は１〜３の整数を表す。）

(In the formula, R ^st represents a hydrogen atom or a methyl group, and m ₀₁ represents an integer of 1 to 3.)

（式中、Ｒ^ｓｔは水素原子又はメチル基を表し、Ｒ^０１は炭素数１〜５のアルキル基を表し、ｍ_０２は０または１〜３の整数を表す。）

^{(Wherein, R st} is a hydrogen atom or a methyl ^{group, R 01} represents an alkyl group having 1 to 5 carbon _{atoms, m 02} represents an integer of 0 or 1-3.)

In the above general formula (Tp) -1-2-1, R ^st is a hydrogen atom or a methyl group, and preferably a hydrogen atom.
m ₀₁ is an integer of 1 to 3. Of these, m ₀₁ is preferably 1.
The position of the hydroxyl group may be any of the o-position, the m-position, and the p-position. preferable. When m ₀₁ is 2 or 3, any substitution position can be combined.

In the general formula (Tp) -1-3-1, R ^st is a hydrogen atom or a methyl group, and is preferably a hydrogen atom.
R ⁰¹ is a linear or branched alkyl group having 1 to 5 carbon atoms, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group. Group, neopentyl group and the like. Industrially, a methyl group or an ethyl group is preferable.

_M02 is 0 or an integer of 1 to 3. Among these, _m02 is preferably 0 or 1, and particularly preferably 0 industrially.
When m ₀₂ is 1, R ⁰¹ may be substituted at any of the o-position, m-position, and p-position, and when m ₀₂ is 2 or 3, any substitution is possible. The positions can be combined.

  As the structural unit (Tp) -1-4, the structural unit represented by any one of the general formulas (a4-1) to (a4-7), or the following general formula (Tp) -1-4-1 The structural unit represented is mentioned.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｒｔｐ^０４は、炭素数１〜１０の直鎖状のアルキル基である。］

[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, and Rtp ⁰⁴ is a linear alkyl group having 1 to 10 carbon atoms. ]

As the polymer compound (Tp) that is preferably contained in a solution containing an acid or a thermal acid generator, the structural unit represented by (Tp) -1-2-1 and the above (Tp) -1--3- A combination of the structural unit represented by 1 and a combination of the structural unit represented by (Tp) -1-2 and the structural unit represented by (Tp) -1-3, (Tp) -1 A combination including two or more structural units represented by -1, a combination including two or more structural units represented by the above (Tp) -1-4, and polyvinyl alcohol are preferable.
By using the polymer compound (Tp) in the above combination, it is considered that the dissolution of the first resist pattern and the overall mixing of the first layer and the solvent layer can be prevented. In addition to this, it is considered that the solubility in an organic solvent can be improved in organic solvent development in a later step.

In the solution containing the acid or thermal acid generator, the above-described polymer compound (Tp) may be used singly or in combination of two or more.
In the present invention, the content of the polymer compound (Tp) in the solution containing the acid or thermal acid generator is preferably such that the solid content concentration of the solution containing the acid or thermal acid generator is 50 to 80 parts by mass. A mass part is more preferable and 60-73 mass parts is further more preferable.

〔solvent〕
In the present invention, a solvent that is preferably contained in a solution containing an acid or a thermal acid generator (hereinafter sometimes referred to as “solvent (B)”) will be described. In step B, a solution containing an acid or a thermal acid generator is applied so as to cover the first resist pattern, thereby forming a first layer. For this reason, it is preferable that the solvent which the solution containing an acid or a thermal acid generator contains is a solvent which does not dissolve the first resist pattern.
Specifically, it is preferable to employ water, an ether solvent, or a linear monovalent alcohol having 1 to 10 carbon atoms.
The ether solvent is an organic solvent containing C—O—C in the structure. Examples include diethyl ether, 1- (isopentyloxy) -3-methylbutane, diisopropyl ether, tetrahydrofuran and the like.
The alcohol solvent is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specifically, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, benzyl alcohol, 4- Examples thereof include methylpentan-2-ol and 2-methylbutan-1-ol. Among these, 4-methyl-2-pentanol or 2-methylbutan-1-ol is more preferable.

  The amount of the solvent (B) used is not particularly limited, and is set appropriately according to the coating film thickness at a concentration that can be applied onto the first resist pattern. Generally, it is used so that the solid content concentration of the solution containing the acid or thermal acid generator is in the range of 0.1 to 10% by mass, preferably 1 to 5% by mass.

  The film thickness of the first layer is not particularly limited as long as the first resist pattern is covered, but for example, the pattern height of the first resist pattern is preferably 0.2 to 2.0 with respect to 1. 0.3 to 1.8 is more preferable, and 0.5 to 1.2 is particularly preferable.

[Optional step; Step B1]
In this invention, it is preferable to have arbitrary [process B1] after [process B].
Step B1 is a step of applying a solution containing a solvent so as to cover the first layer.
As shown in FIG. 1 (B1), a solution made of a solvent is applied so as to cover the first layer 3 to form a layer B1.
The solution composed of the solvent is applied mainly for the purpose of controlling the action of the acid contained in the first layer formed in the step B. The solution made of the solvent is applied so as to cover the first layer 2 and may be partially mixed with the upper part of the first layer.

The solvent used in step B1 (hereinafter sometimes referred to as “solvent (B1)”) is not particularly limited as long as the action of the acid can be controlled.
As the solvent (B1), in addition to the same solvent as the solvent (B), those listed as the component (S) in the resist composition or a mixed solvent thereof can be used.
Among these, as the solvent (B1), a solvent that does not dissolve the first layer is preferable, and it is preferable to employ a low polarity solvent.
Low-polar solvents include C4-C12 aliphatic hydrocarbon solvents such as butane, pentane, hexane, and octane, aromatic hydrocarbon solvents such as toluene and xylene, and alicyclic hydrocarbon solvents such as cyclohexane. Is mentioned.
Of these, isoamyl ether, diethyl ether, 1- (isopentyloxy) -3-methylbutane, diisopropyl ether, tetrahydrofuran, or a mixed solvent of 1- (isopentyloxy) -3-methylbutane and PGMEA is preferable.

In the present invention, the solution comprising a solvent preferably contains an acid diffusion control agent.
The acid diffusion controller is not particularly limited as long as it acts as a quencher that traps the acid of the acid component in the first layer. In the present invention, it is preferable to employ the nitrogen-containing organic compound component described as the component (D2) in the resist composition.
Among these, alkylamine is preferable, trialkylamine having 5 to 10 carbon atoms is preferable, and tri-n-pentylamine and tri-n-octylamine are preferable.
Moreover, it is good also as an ionic nitrogen-containing organic compound component, and the compound which consists of a cation part represented by the following general formula (Cd) and an anion part represented by the said general formula (d1-1) is preferable.

［Ｒｄ^ｃ１〜Ｒｄ^ｃ３は、それぞれ独立に、置換基を有していてもよいアルキル基である。］

[Rd ^{c1 to} Rd ^c3 are each independently an alkyl group which may have a substituent. ]

In formula (Cd), Rd ^{c1 to} Rd ^c3 are each independently an alkyl group which may have a substituent. Rd ^{c1 to} Rd ^c3 are preferably each independently a linear alkyl group having 1 to 5 carbon atoms.

In the solution composed of the solvent, the above acid diffusion control agent may be used alone or in combination of two or more.
In the solution containing the solvent in the present invention, the content of the acid diffusion controller is preferably 10 to 30 parts by mass, more preferably 12 to 25 parts by mass, and more preferably 15 to 20 parts by mass of the solid content of the solvent. Further preferred.

[Polymer Compound (Cp)]
Suitable polymer compound (Cp) contained in the solvent solution includes the same as the polymer compound (Tp).
Examples of the polymer compound (Cp) include a combination of the structural unit represented by (Tp) -1-2 and the structural unit represented by (Tp) -1-3, and the above (Tp) -1-4. A combination containing two or more structural units represented by the above, a combination of the structural unit represented by (Tp) -1-1 and the structural unit represented by (Tp) -1-4, polyvinyl alcohol, Is preferable.
By using the polymer compound (Cp) in the above combination, it is considered that the dissolution of the first resist pattern and the overall mixing of the first layer and the solvent layer can be prevented. In addition to this, it is considered that the solubility in an organic solvent can be improved in organic solvent development in a later step.

As the solution composed of the solvent, the above-described polymer compound (Cp) may be used alone or in combination of two or more.
In the present invention, in the solution containing the acid or thermal acid generator, the content of the polymer compound (Cp) is preferably such that the solid content concentration of the solution containing the acid or thermal acid generator is 50 to 95 parts by mass. Part is more preferable, and 75 to 85 parts by mass is further preferable.

  In the present invention, the solvent (B) contained in the solution containing the acid or thermal acid generator forming the first layer and the solvent (B1) contained in the solution comprising the solvent are the same or different. Also good. If different, for example, a monohydric alcohol solvent may be selected as the solvent (B), an ether solvent may be employed as the solvent (B1), and a monohydric alcohol solvent may be employed as the solvent (B1). A solvent is selected, an ether solvent may be employed as the solvent (B), water may be selected as the solvent (B), and an ether solvent may be employed as the solvent (B1). As B), a monohydric alcohol solvent may be selected, and water may be adopted as the solvent (B1).

  The usage-amount of a solvent (B1) is not specifically limited, It is a density | concentration which can be apply | coated on a 1st layer, and is suitably set according to a coating film thickness. Generally, it is used so that the solid content concentration of the solution composed of the solvent is 0.1 to 10% by mass, preferably 1 to 5% by mass.

[Step C]
In step C, the structure including the first resist pattern obtained in steps A to B (or steps A to B1) is heated, and the first layer is formed by the action of an acid in the first layer. This is a step of changing the solubility of the resist pattern in the developer. The heat treatment in step C may be performed, for example, at 90 to 110 ° C. for 50 to 120 seconds.

By the process C, as shown in FIG. 1C, the solubility of the first resist pattern surface in the developer can be changed to form the developer insoluble region 1Pa.
In the step A, a positive resist composition is used to form the first resist pattern 1P by alkali development. That is, an alkali-insoluble region is formed on the surface of the first resist pattern 1P.
In step C, the surface containing the first resist pattern obtained in steps A to B (or steps A to B1) is heated to deprotect the surface of the first resist pattern 1P, and organic Solubility in solvents can be reduced.

  In the case where a solution made of a solvent is applied so as to cover the first layer 2 by the step B1, the action of the acid in the first layer above the first resist pattern is suppressed, and the first Since the acid in the first layer on the side surface of the resist pattern is allowed to act, the solubility of the first resist pattern in the central portion and the side wall portion in the developer can be controlled. For this reason, it is thought that pattern separation can be made favorable.

[Step D]
In step D, the coated first resist pattern is developed with an organic solvent, and regions other than the region where the solubility of the first resist pattern in the developer is changed are removed to form a second resist pattern. It is a process.
In step C, as shown in FIG. 1C, in the first resist pattern, a region 1Pa having reduced solubility in an organic solvent and a region 1Pb having solubility in an organic solvent are formed. Therefore, by removing the region (1Pb in FIG. 1C) other than the region where the solubility of the first resist pattern in the developer has changed, the first resist pattern forms a finer split pattern. can do.
In Step D, since the first layer 2 can also be removed by development processing, a finer split pattern of the first resist pattern can be formed.

  As the organic solvent contained in the organic solvent used for development, a solution composed of a solvent, a layer 2 containing an acid or a thermal acid generator, and a region 1Pb having solubility in an organic solvent can be dissolved. What is necessary is just to select suitably from well-known organic solvents. Specific examples include ketone solvents, ester solvents, nitrile solvents, and the like. As the ester solvent, butyl acetate is preferred. As the ketone solvent, methyl amyl ketone (2-heptanone) is preferable.

  The ketone solvent is an organic solvent containing C—C (═O) —C in the structure. The ester solvent is an organic solvent containing C—C (═O) —O—C in the structure. The alcohol solvent is an organic solvent containing an alcoholic hydroxyl group in the structure, and “alcoholic hydroxyl group” means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. The amide solvent is an organic solvent containing an amide group in the structure. The ether solvent is an organic solvent containing C—O—C in the structure. Among organic solvents, there are organic solvents that contain multiple types of functional groups that characterize each of the above solvents in the structure, but in that case, any of the solvent types that contain the functional groups of the organic solvent is applicable. Shall. For example, diethylene glycol monomethyl ether corresponds to both alcohol solvents and ether solvents in the above classification. The hydrocarbon solvent is a hydrocarbon solvent made of hydrocarbon and having no substituent (a group or atom other than a hydrogen atom and a hydrocarbon group).

  Specific examples of each solvent include ketone solvents such as 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutylketone, cyclohexanone, Methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetylalcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, propylene carbonate, γ-butyrolactone, methylamylketone (2- Heptanone) and the like.

  Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono Propyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene Recall monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, Propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxy Nethyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, pyrubin Methyl acid, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, 2-hydroxypropionate Examples include ethyl acid, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate.

Examples of the nitrile solvent include acetonitrile, propionitryl, valeronitrile, butyronitryl and the like.
In the organic developer, a known surfactant can be blended as an additive as required.

  Development processing using an organic developer can be carried out by a known development method, for example, a method in which a support is immersed in the developer for a certain period of time (dip method), or a surface tension of the developer on the surface of the support. A method that swells and rests for a certain period of time (paddle method), a method of spraying developer on the surface of the support (spray method), and a developer coating nozzle that scans at a constant speed on a support that rotates at a constant speed. For example, there is a method of continuously applying the developer (dynamic dispensing method).

After the developing treatment, before the drying, a rinsing treatment can be performed using a rinsing liquid containing an organic solvent. By rinsing, a good pattern can be formed.
As the organic solvent used in the rinsing liquid, for example, organic solvents that are difficult to dissolve the resist pattern among the organic solvents mentioned as the organic solvent used in the organic developer can be used. 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 alcohol solvent used for the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. It is done. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol or 2-hexanol is more preferable.
Any one of these organic solvents may be used alone, or two or more thereof may be mixed and used. Moreover, you may mix and use the organic solvent and water other than the above. However, in consideration of development characteristics, the blending amount of water in the rinsing liquid is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, more preferably 3% by mass or less based on the total amount of the rinsing liquid. Is particularly preferred.
A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. Examples of the surfactant include those described above, and nonionic surfactants are preferable, and fluorine-based surfactants or silicon-based surfactants are more preferable.
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 0.5% by mass with respect to the total amount of the rinse liquid. % Is more preferable.
The rinsing treatment (washing treatment) using the rinsing liquid can be carried out by a known rinsing method. For example, the rinsing liquid is continuously applied onto a support rotating at a constant speed (rotary coating method). A method of immersing the support in a rinsing solution for a certain time (dip method), a method of spraying a rinsing solution on the surface of the support (spray method), and the like.

  According to the resist pattern forming method of the present invention, the second resist pattern as shown in FIG. A so-called split pattern, which is a fine pattern obtained by dividing the first resist pattern, can be satisfactorily formed.

[Step E]
In step E, a pattern reversal composition containing an organic solvent that does not dissolve the second resist pattern is applied, a pattern reversal film is formed, and the second development is performed by alkali development using an alkaline developer. The pattern inversion film is patterned while removing the resist pattern to form a third pattern.
As shown in FIG. 1E, a pattern reversal composition containing an organic solvent that does not dissolve the second resist pattern so as to cover the second resist pattern 1Pa obtained by the steps A to D. The pattern inversion film 3 is formed by coating.

<Pattern reversal composition>
The pattern reversal composition used in the pattern forming method of the present invention comprises an organic solvent that does not dissolve the first resist pattern (hereinafter referred to as “(S ′) component”) and a base material component that constitutes the pattern reversal film. (A ″) (hereinafter referred to as “(A ″) component”).

  When the pattern reversal composition contains the component (S ′), the dissolution of the first resist pattern by the organic solvent in the pattern reversal composition when the pattern reversal composition is applied can be suppressed. It is possible to prevent deterioration or disappearance of the shape of one resist pattern, mixing at the interface between the first resist pattern and the pattern reversal film, and the like.

≪ (S ′) component≫
The component (S ′) is an organic solvent that does not dissolve the first resist pattern.
“Do not dissolve the first resist pattern” in the component (S ′) means that a resist composition is coated on a support and dried to form a resist film having a thickness of 0.2 μm at 23 ° C. When this is immersed in the organic solvent, the disappearance of the resist film or a significant change in the film thickness does not occur even after 60 minutes (preferably the film thickness of the resist film is 0.16 μm or less. It must not be.)
The component (S ′) may be any component that does not dissolve the first resist pattern and can dissolve the components blended in the pattern reversal composition. Among these, alcohol-based organic solvents and ester-based organic solvents are preferable, and ester-based organic solvents are more preferable from the viewpoint of the coating property on the support and the solubility of the components blended in the pattern reversal composition such as the resin component. preferable.
Here, the “ester organic solvent” is a compound containing C—C (═O) —O—C in the structure. An “alcohol-based organic solvent” is an organic solvent containing an alcoholic hydroxyl group in the structure and is a compound in which at least one of the hydrogen atoms of an aliphatic hydrocarbon is substituted with a hydroxyl group, and is liquid at room temperature and normal pressure. It is a certain compound. The structure of the main chain constituting the aliphatic hydrocarbon may be a chain structure, may be a cyclic structure, may have a cyclic structure in the chain structure, The chain structure may contain an ether bond.

  Examples of the ester organic solvent include those exemplified above as the ester organic solvent in the description of the organic solvent contained in the organic developer, and among them, butyl acetate, Ethyl-3-ethoxypropionate is preferred.

As the alcohol organic solvent, monohydric alcohols, dihydric alcohols, derivatives of dihydric alcohols, and the like are preferable.
As the monohydric alcohol, although depending on the number of carbon atoms, a primary or secondary monohydric alcohol is preferable, and a primary monohydric alcohol is most preferable.
Here, the monohydric alcohol means a compound in which one of the hydrogen atoms of a hydrocarbon compound composed only of carbon atoms and hydrogen atoms is substituted with a hydroxyl group, and does not include divalent or higher polyhydric alcohol derivatives. . The hydrocarbon compound may have a chain structure or a cyclic structure.
The dihydric alcohol means a compound in which two hydrogen atoms of the hydrocarbon compound are substituted with a hydroxyl group, and does not include a trihydric or higher polyhydric alcohol derivative.
Examples of the dihydric alcohol derivative include compounds in which one of the hydroxyl groups of the dihydric alcohol is substituted with a substituent (such as an alkoxy group or an alkoxyalkyloxy group).

The boiling point (under normal pressure) of the alcohol-based organic solvent is preferably 80 to 250 ° C., more preferably 90 to 220 ° C., and 100 to 200 ° C. in coating properties and the composition during storage. Most preferable from the viewpoint of stability and baking temperature.
Specific examples of the alcohol-based organic solvent include propylene glycol (PG); 1-butoxy-2-propanol (PGB), n-hexanol, 2-heptanol, 3-heptanol, and 1-heptanol as those having a chain structure. 5-methyl-1-hexanol, 6-methyl-2-heptanol, 1-octanol, 2-octanol, 3-octanol, 4-octanol, 2-ethyl-1-hexanol, 2- (2-butoxyethoxy) ethanol , N-pentyl alcohol, s-pentyl alcohol, t-pentyl alcohol, isopentyl alcohol, isobutanol (also referred to as isobutyl alcohol or 2-methyl-1-propanol, IBA), isopropyl alcohol, 2-ethylbutanol, neopentyl Alcoa , N- butanol, s- butanol, t-butanol, 1-propanol, 2-methyl-1-butanol, 2-methyl-2-butanol, 4-methyl-2-pentanol (MIBC), and the like.
In addition, as those having a cyclic structure, cyclopentanemethanol, 1-cyclopentylethanol, cyclohexanol, cyclohexanemethanol (CM), cyclohexaneethanol, 1,2,3,6-tetrahydrobenzyl alcohol, exo-norbornol, 2-methyl Examples include cyclohexanol, cycloheptanol, 3,5-dimethylcyclohexanol, and benzyl alcohol.

  Among alcohol-based organic solvents, chain-structured monohydric alcohols or dihydric alcohol derivatives are preferred, such as 1-butoxy-2-propanol (PGB); isobutanol (also called isobutyl alcohol or 2-methyl-1-propanol). IBA.), 4-methyl-2-pentanol (MIBC) and n-butanol are preferred, and isobutanol (2-methyl-1-propanol) and 1-butoxy-2-propanol (PGB) are most preferred.

The (S ′) component used in the pattern reversal composition may be a single type or two or more types.
The amount of the component (S ′) used is not particularly limited, and is appropriately set according to the coating film thickness at a concentration that can be applied to a substrate or the like. For example, in the pattern reversal composition, the concentration of the base material component (component (A)) described later is preferably in the range of 0.5 to 20% by mass, more preferably 1.0 to 15% by mass. (S ′) component is used.

Further, the pattern reversal composition may contain an organic solvent other than the (S ′) component (hereinafter referred to as “(S”) component ”) as long as the effect of using the (S ′) component is not impaired. Good.
As the component (S ″), those capable of dissolving the components blended in the pattern reversal composition are preferable. Specifically, in the description of the resist composition described above as the resist material for forming the first resist pattern. The thing similar to the (S) component mentioned is mentioned.
The amount of the component (S ″) is preferably 20% by mass or less, and more preferably 1 to 15% by mass in the total organic solvent used in the pattern reversal composition.
The amount of the total organic solvent used in the pattern reversal composition is not particularly limited, and is usually an amount that makes the pattern reversal composition a liquid having a concentration that can be applied onto the support. For example, it is used so that the solid content concentration of the pattern reversal composition is in the range of 1 to 30% by mass.

≪ (A ″) component≫
The component (A ″) is a base material component constituting the pattern reversal film, and is an organic compound having film forming ability.
As the component (A ″), a base material component having a dissolution rate in an alkali developer of 1.0 to 3.5 nm / s as measured in the following [Method for measuring dissolution rate in alkali developer] is preferable.

[Measurement method of dissolution rate in alkaline developer]
A pattern reversal composition is uniformly applied using a spinner on a support such as a silicon substrate, and a pre-bake (PAB) treatment or the like is performed to form a pattern reversal film. On the other hand, the alkali development is performed, and the dissolution rate (the amount of film reduction per unit time, unit: nm / s) of the pattern reversal film at that time is determined by Nanospec (manufactured by Nanometrics).

  As shown in FIG. 1E, a pattern reversal film 3 is also formed on the second resist pattern 1Pa. In step E, the second resist pattern 1Pa is removed by development processing. If the solubility of the pattern reversal composition in the alkaline developer is within the above range, the pattern reversal above the second resist pattern 1Pa is performed. The film 3 is appropriately dissolved in the developer, and the second resist pattern can be removed satisfactorily.

-Component (A "1) The component (A") preferably contains a resin component (A "1) (hereinafter also referred to as" (A "1) component").
Examples of the component (A ″ 1) include a resin having a structural unit containing a polar group. By having a structural unit containing a polar group, the component (A ″ 1) can be used as the component (S ′). The solubility with respect to a component becomes favorable. In addition, it has moderate solubility in an alkali developer.
Among such (A ″ 1) components, preferred are a hydroxyl group, a cyano group, a carboxy group, a base dissociable group, a group represented by the following general formula (f2-0-1), It has a structural unit (a ″ 1) containing at least one selected from the group consisting of a group represented by the general formula (f2-0-2) and a group represented by the following general formula (f2-0-3) A resin component is mentioned.

［式（ｆ２−０−１）中、Ｑは２価の連結基又は単結合であり、Ｒ^５はフッ素化アルキル基である。式（ｆ２−０−２）中、Ｑ及びＲ^５はいずれも前記と同じである。式（ｆ２−０−３）中、Ｒ^５１，Ｒ^５２はそれぞれ独立して水素原子、炭素数１〜５のアルキル基、フッ素原子、又は炭素数１〜５のフッ素化アルキル基であり、ｍ_ｆ，ｎ_ｆはそれぞれ独立して０〜５の整数（ただし、ｍ_ｆ＋ｎ_ｆ≧１）であり、ｑ_ｆは０〜５の整数である。］

[In formula (f2-0-1), Q represents a divalent linking group or a single bond, and R ⁵ represents a fluorinated alkyl group. In formula (f2-0-2), Q and R ⁵ are the same as described above. In formula (f2-0-3), R ⁵¹ and R ⁵² each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms, m _{f 1} and n _f are each independently an integer of 0 to 5 (however, m _f + n _f ≧ 1), and q _f is an integer of 0 to 5. ]

..Structural unit (a "1):
The structural unit (a ″ 1) includes, as a polar group, a hydroxyl group, a cyano group, a carboxy group, a base dissociable group, a group represented by the general formula (f2-0-1), and the general formula (f2-0-2). ) And at least one selected from the group consisting of groups represented by the general formula (f2-0-3).

"About base dissociable groups"
In the present invention, the “base dissociable group” refers to an organic group that can be dissociated by the action of a base. Examples of the base include an alkaline developer generally used in the lithography field. That is, the “base dissociable group” is a group dissociated by the action of an alkali developer (for example, 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution (23 ° C.)).
The base dissociable group is dissociated by hydrolysis caused by the action of an alkali developer. Therefore, a hydrophilic group is formed simultaneously with the dissociation of the base dissociable group, the hydrophilicity of the component (A ″ 1) is increased, and the affinity for an alkali developer is appropriately improved.

  In the structural unit (a ″ 1), the base dissociable group is not particularly limited as long as it is an organic group corresponding to the above definition, may contain a fluorine atom, and does not contain a fluorine atom. It is preferable that it contains a fluorine atom, and it is particularly preferable that the fluorine atom contained in the structural unit (a ″ 1) exists only in the base dissociable group. When the base-dissociable group contains a fluorine atom, when the base-dissociable group is dissociated by the action of the alkali developer, the fluorine atom is also dissociated from the structural unit (a ″ 1). Get higher.

Specific examples of the base dissociable group include groups represented by general formulas (II-1) to (II-5) shown below.
In the present invention, the base dissociable group is preferably at least one selected from the group consisting of groups represented by the following general formulas (II-1) to (II-5), and is hydrophilic during development. It is particularly preferable that it is a group represented by each of the following general formulas (II-1), (II-4), and (II-5) from the viewpoints of excellent characteristics and easy synthesis.

［式中、Ｒ^０はそれぞれ独立してフッ素原子を有していてもよい有機基である。］

[Wherein, R ⁰ is each independently an organic group optionally having a fluorine atom. ]

In Formulas (II-1) to (II-5), R ⁰ is an organic group that may have a fluorine atom.
An “organic group” is a group containing at least one carbon atom.
The structure of R ⁰ may be linear, branched or cyclic, and is preferably linear or branched.
In R ⁰ , the organic group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and most preferably 1 to 5 carbon atoms.
R ⁰ preferably has a fluorination rate of 25% or more, more preferably 50% or more, and particularly preferably 60% or more.
The “fluorination rate” is a ratio (%) of (number of fluorine atoms) to (total number of hydrogen atoms and fluorine atoms) in the organic group.

Preferred examples of R ⁰ include a methyl group, an ethyl group, and a fluorinated hydrocarbon group that may have a substituent.

Regarding the fluorinated hydrocarbon group which may have a substituent in R ⁰ , the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, A hydrogen group is preferred.
The aliphatic hydrocarbon group is a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be either saturated or unsaturated, but is usually preferably saturated.
That is, R ⁰ is preferably a fluorinated saturated hydrocarbon group or a fluorinated unsaturated hydrocarbon group, particularly preferably a fluorinated saturated hydrocarbon group, that is, a fluorinated alkyl group.
Examples of the fluorinated alkyl group include groups in which some or all of the hydrogen atoms of the unsubstituted alkyl group described below are substituted with fluorine atoms. The fluorinated alkyl group may be a group in which some of the hydrogen atoms of the unsubstituted alkyl group are substituted with fluorine atoms, or a group in which all of the hydrogen atoms of the unsubstituted alkyl group are substituted with fluorine atoms ( Perfluoroalkyl group).

The unsubstituted alkyl group may be linear, branched or cyclic, or a combination of a linear or branched alkyl group and a cyclic alkyl group.
As an unsubstituted linear alkyl group, C1-C10 is preferable and C1-C8 is more preferable. Specifically, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n- A decyl group etc. are mentioned.
As an unsubstituted branched alkyl group, C3-C10 is preferable and C3-C8 is more preferable. As the branched alkyl group, a tertiary alkyl group is preferable.
Examples of the unsubstituted cyclic alkyl group include groups in which one hydrogen atom has been removed from a monocycloalkane or a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane. Specific examples include monocycloalkyl groups such as cyclopentyl group and cyclohexyl group; polycycloalkyl groups such as adamantyl group, norbornyl group, isobornyl group, tricyclodecyl group, and tetracyclododecyl group.
A combination of an unsubstituted 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, or a cyclic alkyl group And a group having a linear or branched alkyl group bonded thereto as a substituent.

  Examples of the substituent that the fluorinated hydrocarbon group may have include an alkyl group having 1 to 5 carbon atoms.

In R ⁰ , the fluorinated alkyl group is preferably a linear or branched fluorinated alkyl group. In particular, a group represented by the following general formula (III-1) or (III-2) is preferable, and among them, a group represented by the formula (III-1) is more preferable.

［式（ＩＩＩ−１）中、Ｒ^４１’は無置換の炭素数１〜９のアルキレン基であり、Ｒ^４２’は炭素数１〜９のフッ素化アルキル基である。但し、Ｒ^４１’とＲ^４２’との炭素数の合計は１０以下である。また、式（ＩＩＩ−２）中、Ｒ^７４〜Ｒ^７６は、それぞれ独立に、炭素数１〜５の直鎖状のアルキル基であり、Ｒ^７４〜Ｒ^７６の少なくとも１つはフッ素原子を有するアルキル基である。］

[In the formula (III-1), R ⁴¹ ′ is an unsubstituted alkylene group having 1 to 9 carbon atoms, and R ⁴² ′ is a fluorinated alkyl group having 1 to 9 carbon atoms. However, the total number of carbon atoms of R ⁴¹ ′ and R ⁴² ′ is 10 or less. In formula (III-2), R ^{74 to} R ⁷⁶ are each independently a linear alkyl group having 1 to 5 carbon atoms, and at least one of R ^{74 to} R ⁷⁶ has a fluorine atom. It is an alkyl group. ]

In formula (III-1), the alkylene group for R ⁴¹ ′ may be linear, branched or cyclic, and is preferably linear or branched. Moreover, 1-5 are preferable.
R ⁴¹ ′ is particularly preferably a methylene group, an ethylene group or a propylene group.
As R ⁴² ′, a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a perfluoroalkyl group is particularly preferable. Of these, a trifluoromethyl group (—CF ₃ ), a tetrafluoroethyl group (—C ₂ F ₄ H), and —C ₂ F ₅ are preferable.
In formula (III-2), the alkyl group represented by R ^{74 to} R ⁷⁶ is preferably an ethyl group or a methyl group, and particularly preferably a methyl group. Any one of the alkyl groups of R ^{74 to} R ⁷⁶ may be a fluorinated alkyl group, and all may be a fluorinated alkyl group.

"Group represented by general formula (f2-0-1)"
In the formula (f2-0-1), Q represents a divalent linking group or a single bond.
Examples of the divalent linking group include methylene, ethylene, propylene, isopropylene, cyclopropylene, n-butylene, isobutylene, pentene, isopentene, neopentene, cyclopentylene, cyclo C1-C8 linear, branched or cyclic alkylene groups, such as a hexylene group, a cycloheptylene group, and a cyclooctylene group, are mentioned. Further, the divalent linking group in Q may contain a hetero atom, such as an ether group, an ester group, a group in which at least one of a hydrogen atom and / or a carbon atom in the above-described alkylene group is substituted with a hetero atom, etc. Also mentioned. Among these, a linear alkylene group is preferable from the viewpoint of ease of synthesis, and a methylene group is particularly preferable.

R ⁵ is a fluorinated alkyl group. The fluorinated alkyl group is a group in which part or all of the hydrogen atoms of a linear, branched or cyclic alkyl group are substituted with fluorine atoms.
As such a linear or branched alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, an alkyl group having 1 to 8 carbon atoms is more preferable, and an alkyl group having 1 to 5 carbon atoms is more preferable. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a pentyl group, an isopentyl group, and a neopentyl group, and a methyl group is particularly preferable.
The cyclic alkyl group preferably has 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
The fluorination rate of the fluorinated alkyl group is preferably 10 to 100%, more preferably 30 to 100%, particularly preferably 50 to 100%, and 100%, that is, all hydrogen atoms are substituted with fluorine atoms. Most preferred. When the fluorination rate is 10% or more, the hydrophobicity of the pattern reversal film surface increases, and the dissolution rate in the alkaline developer can be controlled.
Among these, as the fluorinated alkyl group for R ^5, a linear or branched fluorinated alkyl group is preferable, a fluorinated alkyl group having 1 to 5 carbon atoms is more preferable, and a hydrogen atom of the alkyl group is Particularly preferred are perfluoroalkyl groups all substituted with fluorine atoms. Specific examples of the perfluoroalkyl group include a trifluoromethyl group and a pentafluoroethyl group, and the trifluoromethyl group is most preferable.

"Group represented by general formula (f2-0-2)"
In the formula (f2-0-2), Q and ^{R 5} are both the same as Q and ^{R 5} in Formula (f2-0-1).

"Group represented by general formula (f2-0-3)"
In the formula (f2-0-3), R ⁵¹ and R ⁵² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms. .
In R ⁵¹ and R ⁵² , the alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group. Group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like, and a methyl group is preferable.
In R ⁵¹ and R ⁵² , examples of the fluorinated alkyl group include those in which at least one hydrogen atom of the alkyl group of R ⁵¹ and R ⁵² is substituted with a fluorine atom.
Among ^these, as R ^{51, R 52,} preferably is a hydrogen atom, and most preferably both hydrogen atoms.
m _f and n _f are each independently an integer of 0 to 5 (however, m _f + n _f ≧ 1), preferably an integer of 1 to 3, from the viewpoint of the dissolution rate in an alkaline developer, Most preferably, m _f and n _f are both 1.
q _f is an integer of 0 to 5, preferably an integer of 0 to 3, more preferably 0 or 1, and most preferably 1.

  Examples of the structural unit containing a group represented by the formula (f2-0-3) include a structural unit containing a group represented by the following general formula (f2-0-3-1).

［式中、Ｒ^５１，Ｒ^５２、ｍ_ｆ，ｎ_ｆ、ｑ_ｆはそれぞれ上記と同様である。Ｒ^５３，Ｒ^５４はそれぞれ独立して水素原子、炭素数１〜５のアルキル基、フッ素原子、又は炭素数１〜５のフッ素化アルキル基であり、ｐ_ｆは１〜５の整数である。］

[Wherein, R ⁵¹ , R ⁵² , m _f , n _f and q _f are the same as defined above. Each R ^{53, R 54} independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated alkyl group of 1 to 5 carbon atoms, _{p f} is an integer from 1 to 5. ]

In the formula (f2-0-3-1), R ⁵³ and R ⁵⁴ may be the same as R ⁵¹ and R ⁵² , respectively. Of these, a hydrogen atom is preferable, and it is most preferable that both are hydrogen atoms.
_pf is an integer of 1 to 5, preferably an integer of 1 to 3, more preferably 1 or 2, and particularly preferably 2.

  Among these, the polar group in the structural unit (a ″ 1) is particularly preferably at least one selected from the group consisting of a hydroxyl group and a group represented by the general formula (f2-0-3).

  The structural unit (a ″ 1) is bonded to, for example, a structural unit derived from hydroxystyrene, a structural unit whose main chain is cyclic (hereinafter referred to as “main-chain cyclic structural unit”), or an α-position carbon atom. Any of structural units derived from an acrylate ester in which a hydrogen atom may be substituted with a substituent may be used. Among these, a structural unit derived from hydroxystyrene, which is bonded to a carbon atom at the α-position The hydrogen atom is particularly preferably a structural unit derived from an acrylate ester which may be substituted with a substituent.

In the present invention, the “main chain cyclic structural unit” has a monocyclic or polycyclic ring structure, and at least one, preferably two or more carbon atoms on the ring of the ring structure have a main chain. A constituent unit. By including the main chain cyclic structural unit, a pattern reversal film having high hydrophobicity on the film surface is obtained, and etching resistance is also improved. The reason for this is presumed that the carbon density is high due to the cyclic main chain.
Examples of the main chain cyclic structural unit include a structural unit derived from polycycloolefin, and a structural unit derived from bicyclo [2.2.1] -2-heptene (norbornene), tetracyclo [4 .4.0.1 ^2.5 . 1. ^7.10 ] A structural unit derived from -3-dodecene, or a substituent on these ring skeletons.
As the main chain cyclic structural unit, specifically, at a specific position on the ring of the structural unit exemplified above, at least a group represented by the general formula (f2-0-1) as a substituent, What has group represented by general formula (f2-0-2) or group represented by the said general formula (f2-0-3) is mentioned.

  The structural unit (a ″ 1) is preferably a structural unit represented by the following general formula (a ″ 11-1) (hereinafter, this structural unit is referred to as “structural unit (a ″ 11)”).

... Structural unit (a "11)
As the structural unit (a ″ 1), the following general formula (S ′) has good solubility in the component (S ′), moderate solubility in an alkali developer, and excellent etching resistance. A structural unit represented by the formula (a ″ 11-1) (hereinafter, this structural unit is referred to as “structural unit (a ″ 11)”) can be preferably exemplified.

［式中、Ｒ^２０は水素原子又は炭素数１〜５のアルキル基であり；Ｒ^６は炭素数１〜５のアルキル基であり；ｐは１〜３の整数であり；ｑは０〜２の整数である。］

[Wherein, R ²⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R ⁶ is an alkyl group having 1 to 5 carbon atoms; p is an integer of 1 to 3; q is 0 to 2] Is an integer. ]

In the formula (a ″ 11-1), as the alkyl group having 1 to 5 carbon atoms in R ²⁰ , specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert group -Linear or branched alkyl groups, such as a butyl group, a pentyl group, an isopentyl group, and a neopentyl group.
R ²⁰ is particularly preferably a hydrogen atom or a methyl group.

p is an integer of 1 to 3, preferably 1.
The bonding position of the hydroxyl group may be any of the o-position, m-position and p-position of the phenyl group. When p is 1, the p-position is preferred because it is readily available and inexpensive. When p is 2 or 3, arbitrary substitution positions can be combined.

q is an integer of 0-2. Among these, q is preferably 0 or 1, and is preferably 0 industrially.
As the alkyl group for R ^6, the same alkyl groups as those for R ²⁰ can be used.
When q is 1, the substitution position of R ⁶ may be any of the o-position, m-position, and p-position. When q is 2, arbitrary substitution positions can be combined. At this time, the plurality of R ⁶ may be the same or different.

As the structural unit (a ″ 11), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a ″ 11) in the component (A ″ 1) is preferably 40 to 75 mol% based on the total of all structural units constituting the component (A ″ 1), and is preferably 50 to 70%. More preferably, it is mol%, and it is further more preferable that it is 55-65 mol%.
When the proportion of the structural unit (a ″ 11) is equal to or higher than the lower limit value of the range, a predetermined alkali solubility is easily obtained when the pattern reversal composition is obtained, and when the ratio is equal to or lower than the upper limit value of the range, Good balance with other structural units.

..Structural unit (a "2):
The component (A ″ 1) is a structural unit other than the structural unit (a ″ 1) (hereinafter, this structural unit is referred to as “structural unit (a ″ 2)”) as long as the effects of the present invention are not impaired. ) May be included.
The structural unit (a ″ 2) is not particularly limited as long as it is a structural unit that is not classified into the above-mentioned structural unit (a ″ 1). A number of hitherto known materials can be used for resist resins such as
Examples of the structural unit (a ″ 2) include a structural unit derived from styrene, the structural unit (a1) described above, the structural unit (a4) described above, and a polycycloolefin having no substituent. Examples of the unit include structural units derived from polycycloolefins having a polycyclic alicyclic group as a substituent.
Examples of the structural unit derived from a polycycloolefin having no substituent include bicyclo [2.2.1] -2-heptene (norbornene) and tetracyclo [4.4.0.12.5.1.7. 10] -3-dodecene and the like.
In addition, as a structural unit derived from a polycycloolefin having a polycyclic alicyclic group as a substituent, as a substituent on a ring of a structural unit derived from a polycycloolefin having no substituent, Examples include structural units having a polycyclic group such as a tricyclodecanyl group, an adamantyl group, and a tetracyclododecanyl group.
Among the above, as the structural unit (a ″ 2), it is preferable to use the structural unit derived from styrene and the above-described structural unit (a1) because the solubility in an alkali developer can be easily adjusted.

In addition to the structural unit (a ″ 1), the component (A ″ 1) is further referred to as a structural unit derived from styrene as the structural unit (a ″ 2) (hereinafter referred to as “structural unit (a ″ 21)”). ) Is preferred.
By having the structural unit (a ″ 21) as the structural unit (a ″ 2), the solubility in an alkali developer can be easily adjusted. Moreover, when it is used as a pattern reversal film, heat resistance and dry etching resistance are improved.
Preferred examples of the structural unit (a ″ 21) include structural units represented by general formula (a ″ 21-1) shown below.

［式中、Ｒ^２０は前記と同じであり；Ｒ^４は炭素数１〜５のアルキル基であり；ｒは０〜３の整数である。］

[Wherein, R ²⁰ is the same as described above; R ⁴ is an alkyl group having 1 to 5 carbon atoms; and r is an integer of 0 to 3]. ]

"In ^{(21-1, R 20} is the formula (a Formula a)" is the same as ^{R 20} in 11-1).
In the formula (a ″ 21-1), examples of the alkyl group for R ⁴ include the same as the alkyl group for R ^{6 in} the general formula (a ″ 11-1).
r is an integer of 0 to 3, preferably 0 or 1, and industrially particularly preferably 0.
When r is 1, the substitution position of R ⁴ may be any of the o-position, m-position and p-position of the phenyl group. When r is 2 or 3, arbitrary substitution positions can be combined. At this time, the plurality of R ⁴ may be the same or different.

As the structural unit (a ″ 21), one type of structural unit may be used alone, or two or more types of structural units may be used in combination.
In the component (A ″ 1), the proportion of the structural unit (a ″ 21) is preferably 10 to 25 mol% with respect to the total of all the structural units constituting the component (A ″ 1). It is more preferable that it is mol%, and it is further more preferable that it is 10-15 mol%.
When the proportion of the structural unit (a ″ 21) is less than or equal to the upper limit value of the range, a predetermined alkali solubility is easily obtained when the pattern reversal composition is used, and when the proportion is equal to or greater than the lower limit value of the range, Good balance with other structural units.

Further, the component (A ″ 1) is added to the structural unit (a ″ 1), or in addition to the structural unit (a ″ 1) and the structural unit (a ″ 21). You may have resin which has a structural unit (a1).
By adopting the above-described structural unit (a1) as the structural unit (a ″ 2), the solubility in an alkali developer can be easily adjusted. Further, the reversal of a good shape with higher resolution is possible. A pattern can be formed.
The structural unit (a1) in the component (A ″ 1) 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, A structural unit containing an acid-decomposable group whose polarity increases by action (hereinafter also referred to as “structural unit (a” 22-1) ”); or a hydrogen atom in a hydroxyl group of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative Is preferably a structural unit (hereinafter also referred to as “structural unit (a ″ 22-2)”) in which at least a part thereof is protected by a substituent containing the acid decomposable group.
When the structural unit (a1) in the component (A ″ 1) is the structural unit (a ″ 22-1), the structural unit containing an acid dissociable group represented by the general formula (a1-r-2) described above is Preferably, the structural unit containing the group represented by the general formula (a1-r2-2) is more preferable.
When the structural unit (a1) in the component (A ″ 1) is the structural unit (a ″ 22-2), the acid dissociable group (acetal acid dissociation represented by the general formula (a1-r-1) described above) A structural unit containing a functional group).

... Structural unit (a "23)
In the component (A ″ 1), the structural unit (a ″ 2) preferably includes a structural unit (a ″ 23) having a silicon atom. The structural unit (a ″ 23) has the following general formula: The structural unit represented by (a ″ 23-1) is preferable. By employing the structural unit having a silicon atom, the etching resistance of the pattern reversal film can be improved.

［式中、Ｒ^２０は前記と同じであり；Ｒ^２３はアルキル基の一部の炭素原子がケイ素原子により置換された基であり；ｒは１〜３の整数である。］

[Wherein, R ²⁰ is the same as defined above; R ²³ is a group in which a part of carbon atoms of the alkyl group is substituted with a silicon atom; ]

Specific examples of the alkyl group for R ²³ include linear groups such as 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, and a neopentyl group. Or a branched alkyl group is mentioned.
R ²³ is preferably an isopropyl group in which some carbon atoms are substituted with silicon atoms.

  As the structural unit (a ″ 23) having a silicon atom, a cage-type silsesquioxane (POSS) structure-containing structural unit is also suitable.

(Cage-type silsesquioxane (POSS) structure-containing structural unit)
The component (A ″ 1) preferably contains a cage-type silsesquioxane (POSS) structure-containing structural unit. The cage-type silsesquioxane (POSS) structure-containing structural unit has the following general formula: And a structural unit represented by (POSS-1).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基を表す。Ｖ^０は置換基を有していてもよい２価の炭化水素基を表す。Ｒ^０は置換基を有していてもよい１価の炭化水素基を表し、複数のＲ^０はそれぞれ同じであってもよく異なっていてもよい。＊は結合手を示す。］

[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. V ⁰ represents a divalent hydrocarbon group which may have a substituent. R ⁰ represents a monovalent hydrocarbon group which may have a substituent, and a plurality of R ⁰ may be the same or different. * Indicates a bond. ]

In the formula (POSS-1), the alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group or an ethyl group. Propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms 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.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is most preferably a hydrogen atom or a methyl group in terms of industrial availability.

In the formula (POSS-1), the monovalent hydrocarbon group for R ⁰ preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms. However, the carbon number does not include the carbon number in the substituent described later.
The monovalent hydrocarbon group for R ⁰ may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and particularly preferably an aliphatic hydrocarbon group. It is more preferably an aliphatic saturated hydrocarbon group (alkyl group).
More specifically, examples of the alkyl group include a chain aliphatic hydrocarbon group (a linear or branched alkyl group) and an aliphatic hydrocarbon group having a ring in the structure.
The linear alkyl group preferably has 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, and still more preferably 1 to 3 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, and an n-propyl group are preferable, a methyl group, an ethyl group, or an isobutyl group is more preferable, an ethyl group or an isobutyl group is further preferable, and an ethyl group is particularly preferable.
The branched alkyl group preferably has 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, and the like, and an isopropyl group or a tert-butyl group is most preferable.
Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group is the chain described above. Examples thereof include a group bonded to the terminal of a chain-like aliphatic hydrocarbon group or a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of the chain-like aliphatic hydrocarbon group described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 8 carbon atoms, more preferably 4 to 6 carbon atoms, and may be a polycyclic group or a monocyclic group. . As the monocyclic group, a group in which one or more hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic group, a group in which one or more 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, And tetracyclododecane.

The chain-like aliphatic hydrocarbon group may 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, and an oxygen atom (= O).
The cyclic aliphatic hydrocarbon group may 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, and an oxygen atom (= O).

When the monovalent hydrocarbon group in R ⁰ is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a monovalent hydrocarbon group having at least one aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. It is preferable that carbon number of an aromatic ring is 5-30, 5-20 are more preferable, 6-15 are more preferable, and 6-12 are especially preferable. However, the carbon number does not include the carbon number in the substituent described later.
Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms, and the like. Can be mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); an aromatic compound containing two or more aromatic rings A group in which one hydrogen atom is removed from (for example, biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl groups such as 2-naphthylethyl group) and the like.
The alkylene group bonded to the aryl group or heteroaryl 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. 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).

In the formula (POSS-1), the divalent hydrocarbon group for V ⁰ 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 V ⁰ 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 having 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.

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 a polycyclic group or a monocyclic group. 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 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. Adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. It is preferable that carbon number of an aromatic ring is 5-30, 5-20 are more preferable, 6-15 are more preferable, and 6-12 are especially preferable. However, the carbon number does not include the carbon number in the substituent described later.
Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms, and the like. Can be mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings A group obtained by removing two hydrogen atoms from (for example, biphenyl, fluorene, etc.); 1 of the hydrogen atoms of a group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring A group substituted with an alkylene group (for example, an aryl group in an arylalkyl group such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) A group in which one atom is further removed).
The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

Specific examples of the structural unit represented by the formula (POSS-1) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

As the structural unit (a ″ 1) in the component (A ″ 1), one type of structural unit may be used, or two or more types may be used in combination.
In the component (A ″ 1), the proportion of the structural unit (a ″ 1) is preferably 20 to 50 mol% based on the total of all structural units constituting the component (A ″ 1). More preferably, it is mol%, and it is further more preferable that it is 20-40 mol%.
When the proportion of the structural unit (a ″ 1) is not less than the lower limit of the range, moderate alkali solubility can be easily obtained when the pattern reversal composition is obtained. If the reversal pattern has a shape that is less than or equal to the upper limit of the range, the balance with other structural units is good.

In the component (A ″ 1), the proportion of the structural unit (a ″ 2) is preferably 1 to 50 mol% with respect to the total of all structural units constituting the component (A ″ 1). More preferably, it is -40 mol%, and it is further more preferable that it is 3-35 mol%.
In the component (A ″ 1), the proportion of the structural unit (a ″ 21) is preferably 20 to 40 mol% based on the total of all structural units constituting the component (A ″ 1). More preferably, it is -35 mol%, and it is further more preferable that it is 25-35 mol%.
In the component (A ″ 1), the proportion of the structural unit (a ″ 23) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A ″ 1). More preferably, it is -25 mol%, and it is further more preferable that it is 15-25 mol%.
In the component (A ″ 1), the proportion of the (POSS) structure-containing structural unit is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A ″ 1). It is more preferably ˜25 mol%, and further preferably 5 to 20 mol%.

As the component (A ″ 1), a resin component having the structural unit (a ″ 1) (hereinafter, this resin component is referred to as “(A ″ 1-1) component”) is preferable.
Preferable examples of the component (A ″ 1-1) include a copolymer having the structural unit (a ″ 1) and the structural unit (a ″ 2). The structural unit (a ″ 1) ) And the structural unit (a ″ 2) are preferably a copolymer having the structural unit (a ″ 11) and the structural unit (a ″ 21), and the structural unit (a ″ 11). A copolymer having a structural unit (a ″ 11) having a structural unit (a4) and a structural unit (a ″ 23), a structural unit (a ″ 11) and a (POSS) structure-containing structural unit. Having a copolymer.

As the component (A ″ 1), one type may be used alone, or two or more types may be used in combination.
As the component (A ″ 1), a copolymer containing the following combination of structural units is particularly preferable.

In the formula (A "1-11) ~ (A " 1-13), R 20, R 6, p, q are, ^R 20 in the formula ^{(a "11-1), R 6} , p, and q are each similar ^.R 4, r are respectively similar to ^R 4, r in the formula (a "21-1). The plurality of R ²⁰ may be the same or different. The description regarding R ²³ and R ^α is the same as described above.

The mass average molecular weight (Mw) of the component (A ″ 1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, It is most preferably 2000 to 20000. If it is not more than the upper limit of this range, it has sufficient solubility in an organic solvent to be used as a resin component for forming the film for pattern reversal, and is not less than the lower limit of this range. Further, the dry etching resistance and the pattern cross-sectional shape become better.
Further, the dispersity (Mw / Mn) of the component (A ″ 1) is not particularly limited, but is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and 1.0 to 2. 5 is most preferred.

The component (A ″ 1) is obtained, for example, by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN). Can do.
Moreover, when it has a main chain cyclic | annular structural unit, (A "1) component is compoundable by the method as described in Unexamined-Japanese-Patent No. 2006-291177, for example.

  The component (A ″) may contain a base component (resin or low molecular compound) other than the component (A ″ 1) described above.

In the pattern reversal composition in the present invention, as the component (A ″), one type may be used alone, or two or more types may be used in combination.
The content of the component (A ″) in the pattern reversal composition may be adjusted according to the film thickness to be formed.

≪Other ingredients≫
In addition to the components (S ′) and (A ″) described above, the pattern reversal composition according to the present invention may further contain a miscible additive such as a pattern reversal film, if desired. Additional resins, surfactants for improving coatability, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like can be added as appropriate.
In particular, the dissolution rate of the pattern reversal film in the alkaline developer can be controlled by using the dissolution inhibitor in combination with the base component (A ″).

-Dissolution inhibitor Specific examples of the dissolution inhibitor include onium salt acid generators exemplified in the description of the component (B) blended in the resist composition described above. Among them, the compound represented by the above formula (b-1) is preferable because it is excellent in the effect of suppressing dissolution in an alkali developer and can be easily controlled to a predetermined dissolution rate.
A dissolution inhibitor may be used individually by 1 type, and may use 2 or more types together.
The content of the dissolution inhibitor in the pattern reversal composition is preferably 25 parts by mass or less, more preferably 0.1 to 20 parts by mass, and 0.5 to 18 parts by mass with respect to 100 parts by mass of the component (A ″). By setting the amount within the above range, the dissolution rate of the pattern reversal film in the alkaline developer can be easily controlled, and a uniform solution can be obtained and the storage stability is improved, which is preferable.

In step E, the pattern reversal composition is uniformly applied using a spinner so as to cover the second resist pattern, and a pre-baking (PAB) process or the like is performed to form a pattern reversal film. Next, the alkali reversal is performed on the pattern reversal film to remove the second resist pattern, and the pattern reversal film is patterned to form a third pattern.
Specifically, as shown in FIG. 1F, the second resist pattern is removed, and a third pattern 3P is formed by patterning the pattern inversion film.
In Step E, for example, a 0.1 to 10 mass% tetramethylammonium hydroxide (TMAH) aqueous solution may be used for the development processing. In order to satisfactorily form the third pattern, the development time is preferably 5 to 40 seconds, and more preferably 10 to 30 seconds.

According to the resist pattern forming method of the present invention, by having the steps A to E, it is possible to form a pattern with a fine line width that is difficult to form by general ArF positive resist patterning. Specifically, in general ArF positive resist patterning, pattern formation with a line width of about 80 nm is the limit, but according to the present invention, a line width of about 80 nm or less, more specifically, a line width of about 60 nm is used. A pattern can be formed.
In addition, when a pattern reversal composition containing a resin component containing a structural unit containing a silicon atom is employed, a pattern with excellent etching resistance can be formed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to a following example.

[Step A]
<Preparation of resist composition>
100 parts by mass of the following polymer compound (A) -1, 10 parts by mass of the following compound (B) -1, 7 parts by mass of the following compound (D) -1, 2 parts by mass of the following polymer compound (F)- 1, 2 parts by mass of salicylic acid and 4000 parts by mass of a solvent (a mixed solvent of PGMEA / PGME / cyclohexanone (mass ratio 45/30/25)) were mixed to prepare a resist composition.

<Formation of alkali development positive resist pattern>
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto a 12-inch silicon wafer using a spinner and baked on a hot plate at 205 ° C. for 60 seconds to be dried. As a result, an organic antireflection film having a thickness of 95 nm was formed.
Next, the resist composition is applied onto the film using a spinner, prebaked (PAB) at a temperature of 90 ° C. for 60 seconds on a hot plate, and dried to obtain a film thickness of 90 nm. The resist film was formed.
Next, the resist film was selectively irradiated with an ArF excimer laser (193 nm) through a mask pattern (binary mask) by an exposure apparatus NSR-S610S (NA = 1.30 Dipole with polano manufactured by Nikon Corporation).
Subsequently, alkali development was performed at 23 ° C. for 10 seconds using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.).
Thereafter, post-exposure heat treatment was performed at 80 ° C. (PEB (° C.)) for 60 seconds.
As a result, the following line & space pattern (hereinafter referred to as “LS pattern”) was formed.
LS pattern 1: 120 nm pitch / 83 nm line, mask size 60 nm
LS pattern 2: 160 nm pitch / 105 nm line, mask size 80 nm

[Step B]
<Preparation of solution containing acid component>
100 parts by mass of the following polymer compound (AP) -1, 40 parts by mass of the following compound (T) -1, 17000 parts by mass of a solvent (4-methyl-2-pentanol), and a solution containing an acid component Adjusted.

<Formation of the first layer>
The solution containing the acid component obtained above was applied onto the first resist pattern obtained in [Step A] using a spinner (1500 rpm) to form a first layer.

[Step B1]
<Preparation of solution containing basic components>
100 parts by mass of the following polymer compound (BP) -1, 20 parts by mass of trioctylamine, and 10000 parts by mass of a solvent (isoamyl ether) were mixed to prepare a solution containing a basic component.

  The solution containing the basic component obtained above was applied onto the first layer obtained in [Step B] using a spinner (1500 rpm).

[Step C]
The structure including the first resist pattern obtained in the steps A to B was baked at 110 ° C. for 60 seconds.
[Step D]
Thereafter, development processing was performed for 13 seconds using butyl acetate. Thereby, a second resist pattern was formed.

[Step E]
<Preparation of pattern reversal composition>
<Synthesis of Polymer Compound 1>
In a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, 20.00 g (123.3 mmol) of Pre-M1, 5.50 g (52.8 mmol) of M2, 38.25 g of ethyl methyl ketone (MEK) ). To this solution, 2.027 g (8.81 mmol) of dimethyl azobisisobutyrate as a polymerization initiator was added and dissolved to prepare a dropping solution.
21.25 g of MEK was heated to 80 ° C. and refluxed, and the dropping solution was added dropwise over 4 hours under a nitrogen atmosphere. After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization solution was dropped into 340 g of heptane, and a polymer was precipitated. The precipitated white powder was filtered off, washed with methanol and dried to obtain 17.88 g of Pre-P1. .
Next, 41.72 g of methanol was added thereto, and 2.12 g (17.3 mmol) of N, N-dimethyl-4-aminopyridine was further added. This system was heated to 70 ° C., methanol was refluxed, and reacted for 12 hours under a nitrogen atmosphere. The obtained solution was dropped into 238.4 g of heptane and dried to obtain 12.80 g of polymer compound 1. The reaction formula is shown below.
Polymer compounds 2 to 4 were synthesized by the same method.
These polymer compounds obtained by the weight average molecular weight in terms of standard polystyrene was measured by GPC (Mw) and the molecular weight dispersity (Mw / Mn), and carbon 13 nuclear magnetic resonance spectra (600MHz_ ¹³ C-NMR) The copolymer composition ratio is shown in Table 1.

  In Table 1, M1 to M5 mean the following monomers.

  The polymer compounds 1 to 4 obtained above were each dissolved in butyl acetate (resin concentration; 1.2% by mass) to prepare compositions 1 to 4 for pattern reversal.

<Formation of reverse pattern>
The pattern reversal compositions 1 to 4 were respectively applied onto the second resist pattern obtained in [Step D] to form a pattern reversal film.
Of the second resist pattern, Examples 1 to 4 were obtained by applying the pattern reversal compositions 1 to 4 to the LS pattern 1, respectively.
Moreover, what applied the composition reversal compositions 1-4 to the LS pattern 2 among the 2nd resist patterns was made into Examples 5-8, respectively.

Thereafter, the mixture was heated at 90 ° C. for 60 seconds, and then at 23 ° C., using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) Alkali development was performed for 30 seconds.
After development, a third pattern was obtained. About this 3rd pattern, pattern length measurement was measured (Hitachi length measurement SEM CG-5000 was used), and the dimension value was calculated | required. The results are shown in Tables 2-3.

  The “first resist pattern” of Comparative Example 1 indicates the minimum space dimension obtained by forming the first resist pattern.

Since the limit resolution of ArF immersion is about 80 nm pitch in the case of LS space, according to the present invention, it was possible to form a pattern with a fine pitch size such as 60 nm. In particular, it was successfully applied to the formation of line and space patterns.
Even at an 80 nm pitch, it was possible to form a space having a size that cannot be resolved by normal ArF exposure.

≪Dry etching evaluation≫
Dry etching evaluation was performed for each of the above resist composition and the pattern reversal compositions 1 to 4.
The above-described resist composition and pattern reversal compositions 1 to 4 were respectively applied on a silicon substrate and baked at 90 ° C. for 60 seconds to form a resin film.
The obtained resin film was etched under the following conditions.
Equipment: TCA-3822
Output: 400W
Chamber pressure: 40Pa
Stage temperature: 40 ° C
Gas type: CF ₄
Gas flow rate: 20 mL / min
Etching time: 30 seconds

  The amount of film reduction per second was calculated from the difference in film thickness before and after etching, and was used as the etch rate (nm / s). The results are shown in Table 4.

  A smaller etch rate means higher etching resistance and easier substrate processing. As shown in the above results, the pattern reversal composition had higher etching resistance than the resist composition. Further, the pattern reversal composition containing the Si unit was preferable because of higher etching resistance.

DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 1P ... 1st resist pattern, 2 ... 1st layer, B1 ... layer, 1Pa ... Developer solution insoluble area | region, 1Pb ... Area | region which has solubility with respect to organic solvent, 3 ... Pattern inversion film, 3P ... Third pattern

Claims (5)

Applying a resist composition on a support, forming a positive resist film, exposing the positive resist film, and performing alkali development to form a first resist pattern; and
Applying a solution containing an acid or thermal acid generator so as to cover the first resist pattern, and forming a first layer; and
After the step B, a step B1 of applying a solution containing an acid diffusion controller and a solvent so as to cover the first layer;
The structure containing the first resist pattern obtained in the steps A , B and B1 is heated, and the solubility of the first resist pattern in the developer is changed by the action of the acid in the first layer. Process C,
Developing the coated first resist pattern with an organic solvent, removing a region other than the region where the solubility of the first resist pattern in the developer is changed, and forming a second resist pattern; and
A pattern reversal composition containing an organic solvent that does not dissolve the second resist pattern is applied to form a pattern reversal film, and the second resist pattern is removed by alkali development using an alkali developer. However, a resist pattern forming method comprising the step E of patterning the pattern reversal film to form a third pattern.   The resist according to claim 1, wherein the pattern reversal composition contains a resin component (A ″ 1), and the resin component (A ″ 1) includes a structural unit having a silicon atom. Pattern forming method. The resist pattern formation method of Claim 1 or 2 in which the said thermal acid generator contains the compound represented by either of the following general formula (T1-1)-(T1-3).

[Wherein, Rt ¹⁰¹ and Rt ^{104 to} Rt ¹⁰⁸ each independently have a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. A chain alkenyl group which may be present. Rt ¹⁰⁴ and Rt ¹⁰⁵ may be bonded to each other to form a ring. Any two of Rt ^{106 to} Rt ¹⁰⁷ may be bonded to each other to form a ring. Rt ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Yt ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. Vt ^{101 to} Vt ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. Lt ^{101 to} Lt ¹⁰² are each independently a single bond or an oxygen atom. Lt ^{103 to} Lt ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —. Rt ^{301 to} Rt ³⁰⁴ are each independently a hydrogen atom or a linear, branched or cyclic fluorinated alkyl group having 1 to 12 carbon atoms. Rt ^{301 to} Rt ³⁰³ may be bonded to each other to form a ring together with the nitrogen atom in the formula. ] The solution containing the acid or thermal acid generator contains a polymer compound,
The resist pattern formation method of any one of Claims 1-3 in which the said high molecular compound has a structural unit (a3) containing a polar group containing aliphatic hydrocarbon group.   The resist pattern forming method according to any one of claims 1 to 4, wherein the solution containing the acid or the thermal acid generator contains a linear or branched monovalent alcohol having 1 to 10 carbon atoms.

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