JP2013061477A - Resist composition, and method for forming resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition excellent in a lithography characteristic and pattern shape, and a method for forming a resist pattern.SOLUTION: The resist composition contains a base component (A) which generates an acid by exposure and whose dissolubility to a developer liquid changes by action of the acid. The component (A) contains a structural unit (a0-1) represented by the formula (a0-1), and a resin component (A1) having a structural unit (a0-2) that generates acid by exposure. In the formula, R represents a hydrogen atom, 1-5C alkyl group, or 1-5C alkyl halide, and Rrepresents a divalent linking group.

Description

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

In lithography technology, a resist film made of a resist material is formed on a support, the resist film is selectively exposed with radiation such as light or electron beam, and subjected to a development treatment, whereby the resist is formed. A step of forming a resist pattern having a predetermined shape on the film is performed. 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, pattern miniaturization is rapidly progressing due to the advancement of lithography technology. As a technique for miniaturization, the exposure light source is generally increased in energy (shorter wavelength). 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. In addition, studies have been made on electron beams, EUV (extreme ultraviolet rays), X-rays, and the like that have higher energy than these excimer lasers.
Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist composition containing an acid generator that generates an acid upon exposure is used.

As the chemically amplified resist composition, a composition in which an acid generator and a base material component for forming a film are blended is generally used.
Examples of acid generators used in such resist compositions include onium salt acid generators, oxime sulfonate acid generators, diazomethane acid generators, nitrobenzyl sulfonate acid generators, and imino sulfonate acid generators. A wide variety of compounds such as disulfone acid generators are known.
Further, as the base material component, a base material component whose solubility in a developer can be changed by the action of an acid generated from an acid generator is usually used. For example, in the case of an alkali development process using an alkali developer as a developer, a substrate component whose solubility in an alkali developer is changed by the action of an acid is used. When selective exposure is performed on a resist film formed using such a chemically amplified resist composition, an acid is generated from the acid generator component in the exposed area, and the alkali component of the base material component is developed by the action of the acid. The solubility in the solution increases, and the exposed portion becomes soluble in the alkaline developer. Therefore, by developing with an alkaline developer, the exposed portion is dissolved and removed, the unexposed portion remains as a pattern, and a positive resist pattern is formed.
As a base material component used for forming a positive resist pattern in an alkali development process, one having an acid-decomposable group whose polarity is increased by the action of an acid is generally used. Such a base material component becomes highly polar due to the action of an acid, thereby increasing the solubility in an alkali developer. On the other hand, since the solubility in organic solvents is reduced, a process using an organic solvent instead of an alkaline developer (organic developer) (hereinafter referred to as a solvent developing process or negative type) is used. It is sometimes called a development process). When selective exposure is performed on a resist film formed using a chemically amplified resist composition containing a base component having an acid-decomposable group, the solubility in an organic developer is relative in the exposed area. Therefore, by developing with an organic developer, the unexposed portion is dissolved and removed by the organic developer, the exposed portion remains as a pattern, and a negative resist pattern is formed. For example, Patent Document 1 proposes a negative development process.
Currently, a resin (base resin) is widely used as a base component of a chemically amplified resist composition. For example, a base resin of a chemically amplified resist composition used in ArF excimer laser lithography or the like is around 193 nm. In general, a resin (acrylic resin) having a structural unit derived from a (meth) acrylic acid ester in the main chain is generally used (see, for example, Patent Document 2). Here, “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position. “(Meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position.

As chemically amplified resist compositions, those containing a resin component having an acid generating group that generates an acid upon exposure as a base component in the structure have been proposed (for example, Patent Documents 3 to 4).
Such a resin component has both a function as an acid generator and a function as a base material component, and a chemical amplification resist composition can be constituted by only one component. That is, when the resin component is exposed, an acid is generated from the acid generating group in the structure, and the polarity of the base material component changes (increases) by the action of the acid. Therefore, when selective exposure is performed on a resin film (resist film) formed using the resin component, the polarity of the exposed portion changes (increases), so exposure is performed by developing using an alkaline developer. The portion is dissolved and removed to form a positive resist pattern.
Moreover, in the said patent document 4, in order to improve LER, board | substrate adhesiveness, etc., the structural unit containing a hydroxyl group in the structural unit of the specific structure containing an acid generating group, the structural unit containing an acid dissociable dissolution inhibiting group is further included. Are combined.

JP 2008-292975 A JP 2003-241385 A JP-A-10-221852 JP 2006-045311 A

If the resin component having an acid generating group that generates an acid upon exposure is used as the base component in the structure as described above, the solution is less than when the acid generator and the base component are blended as separate components. It is said that the image quality is improved. The reason why the resolution is improved may be that the uniformity of the distribution of the acid generating groups in the resist film is improved by retaining the acid generating groups in the resin component as the base component.
However, such a resin component has low sensitivity at the time of forming a resist pattern, and although the resolution, roughness and shape of the formed resist pattern are improved, it has not been sufficient. Roughness means a rough surface of the resist pattern and causes a defective shape of the resist pattern. For example, the roughness of the pattern sidewall (line edge roughness (LER)) causes a shape defect typified by non-uniform line width in the line and space pattern, distortion around the hole in the hole pattern, and the like. Such a shape defect may adversely affect the formation of a fine semiconductor element, and the improvement becomes more important as the pattern becomes finer.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a resist composition and a resist pattern forming method that are excellent in lithography properties such as sensitivity, roughness, and resolution, and pattern shape.

  A first aspect of the present invention that solves the above problems is a resist composition containing a base component (A) that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid. The base component (A) is a resin component (A1) having a structural unit (a0-1) represented by the following general formula (a0-1) and a structural unit (a0-2) that generates an acid upon exposure. It is a resist composition characterized by containing.

［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、Ｒ^２は２価の連結基である。］

[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 R ² is a divalent linking group. ]

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

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 same applies to the alkyl group in the alkoxy group.
Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms, and the “halogenated alkylene group” is the part of or all of the hydrogen atoms in the alkylene group is a halogen atom. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
A “hydroxyalkyl group” is a group in which part or all of the hydrogen atoms of an alkyl group are substituted with a hydroxyl group.
The “structural unit” means a repeating unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“Exposure” is a concept including general irradiation of radiation.

  ADVANTAGE OF THE INVENTION According to this invention, the resist composition and resist pattern formation method which are excellent in a lithography characteristic and pattern shape can be provided.

≪Resist composition≫
The resist composition of the present invention contains a base component (A) (hereinafter referred to as “component (A)”) that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid.
When a resist film formed using such a resist composition undergoes selective exposure at the time of resist pattern formation, an acid is generated from the component (A), and the acid changes the solubility of the component (A) in the developer. Let me. As a result, while the solubility of the exposed portion of the resist film in the developer changes, the unexposed portion does not change the solubility in the developer, so by developing, the exposed portion in the case of a positive pattern, In the case of a negative pattern, unexposed portions are dissolved and removed to form a resist pattern.
The resist composition of the present invention may be a negative resist composition or a positive resist composition.
In this specification, a resist composition that forms a positive pattern in which an exposed portion is dissolved and removed is referred to as a positive resist composition, and a resist composition that forms a negative pattern in which an unexposed portion is dissolved and removed is referred to as a negative. This is referred to as a type resist composition.

<(A) component>
[(A1) component]
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.
Here, the “base material component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
“Organic compounds having a molecular weight of 500 or more” used as the base 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, a nonpolymer having a molecular weight of 500 or more and less than 4000 is referred to as a low molecular compound.
As the polymer, those having a molecular weight of 1000 or more are usually used. Hereinafter, a polymer having a molecular weight of 1000 or more is referred to as a polymer compound. In the case of a polymer compound, the “molecular weight” is a polystyrene-reduced mass average molecular weight measured by GPC (gel permeation chromatography). Hereinafter, the polymer compound may be simply referred to as “resin”.

In the present invention, the component (A) is a resin component (A1) having a structural unit (a0-1) represented by the general formula (a0-1) and a structural unit (a0-2) that generates an acid upon exposure. ) (Hereinafter referred to as component (A1)).
Since the component (A1) has the structural unit (a0-2), an acid is generated at the time of exposure, and the acid (such as an acid generated from the structural unit (a0-2)) acts on the developer of the base material component. It has the property of changing solubility.

(Structural unit (a0-1))
The structural unit (a0-1) is a structural unit represented by the following general formula (a0-1).

［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、Ｒ^２は２価の連結基である。］

[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 R ² is a divalent linking group. ]

In formula (a0-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
The alkyl group for R is preferably a linear or branched alkyl group, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, A pentyl group, an isopentyl group, a neopentyl group, etc. are mentioned.
Examples of the halogenated alkyl group for R include groups in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Specific examples of the alkyl group include the same alkyl groups as those described above for R. Examples of the halogen atom that replaces the hydrogen atom of the alkyl group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is more preferable, and a hydrogen atom or a methyl group is most preferable in terms of industrial availability.

In formula (a0-1), R ² is a divalent linking group.
Preferred examples of the divalent linking group for R ² include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.
The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with a substituent (a group or atom other than a hydrogen atom).
The hydrocarbon group 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 in R ² may be saturated or unsaturated, and is usually preferably saturated.
More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 1 to 5, and most preferably 1 to 2.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (═O).

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 is preferably one having 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
The alicyclic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom, and a sulfur atom. About an oxygen atom and a sulfur atom, the substituent of the hydrogen atom of an alicyclic hydrocarbon group may be sufficient, and the substituent of the carbon atom which comprises an alicyclic hydrocarbon group may be sufficient.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group as the divalent hydrocarbon group in R ² 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 of the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; a part of carbon atoms constituting the aromatic hydrocarbon ring is hetero 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 obtained by further removing one hydrogen atom from the aryl group in the group); and the like. The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.
The aromatic hydrocarbon group may or may not have a substituent. For example, a hydrogen atom bonded to the aromatic hydrocarbon ring of the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The hetero atom in the “divalent linking group containing a hetero atom” 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.
Specific examples of the divalent linking group containing a hetero atom include —O—, —C (═O) —, —C (═O) —O—, and a carbonate bond (—O—C (═O) —. _{O -), - S -,} - S (= O) 2 -, - S (= O) 2 -O -, - NH -, - NR 04 (R 04 is an alkyl group, a substituent such as an acyl group .)-, -NH-C (= O)-, = N- and the like, and a combination of at least one of these non-hydrocarbon groups and a divalent hydrocarbon group. . Examples of the divalent hydrocarbon group include the same divalent hydrocarbon groups that may have a substituent as described above, and a linear or branched aliphatic hydrocarbon group is preferable. .

Among the above, R ² preferably does not contain an aromatic ring from the viewpoint of reducing side reactions due to the aromatic ring, an aliphatic hydrocarbon group containing a ring in the structure, a divalent linking group containing a hetero atom, Alternatively, a combination thereof is more preferable, and an alicyclic hydrocarbon group, a divalent linking group containing an oxygen atom, or a combination thereof is more preferable.
As the structural unit (a0-1), a structural unit represented by general formula (a0-10) shown below is particularly desirable.

［式中、Ｒは前記同様であり、Ｒ^２０は−Ｃ（＝Ｏ）−Ｏ−を含む２価の連結基であり、Ｒ^２１は脂肪族環式基であり、ｎ２０、ｎ２１はそれぞれ独立に０又は１である。］

[Wherein, R is as defined above, R ²⁰ is a divalent linking group containing —C (═O) —O—, R ²¹ is an aliphatic cyclic group, and n20 and n21 are independent of each other] 0 or 1. ]

In the formula (a0-10), R ²⁰ represents a divalent linking group containing —C (═O) —O—, and the linking group described as the divalent linking group for R ² and —C (═ A combination with O) -O- is mentioned. Among _{them, - (CH 2) n08 -C} (= O) -O- (CH 2) n09 - [ wherein, n08, n09 is an integer of independently 0-3, preferably a 1 . ] Is particularly preferable.
In the formula (a0-10), R ²¹ is an aliphatic cyclic group, and is the same as those exemplified as the aliphatic cyclic group in the divalent linking group of R ² . The aliphatic cyclic group for R ²¹ is preferably a polycyclic group from the viewpoint that the lithography properties are improved by increasing Tg and the etching resistance is further improved. More preferred are polycyclic groups. Of these, a group in which two hydrogen atoms have been removed from adamantane or norbornane is particularly preferred.

Preferred specific examples of the structural unit (a0-10) are shown below. In the following formulae, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (a0-1) contained in the component (A1) may be one type or two or more types.
In the component (A1), the proportion of the structural unit (a0-1) is preferably 1 to 40 mol%, more preferably 3 to 30 mol%, based on the total of all structural units constituting the component (A1). More preferred is ˜25 mol%. Sensitivity can be improved by being 1 mol% or more, and it can balance with another structural unit by being 40 mol% or less.

(Structural unit (a0-2))
The structural unit (a0-2) is a structural unit that generates an acid upon exposure.
The structural unit (a0-2) is not particularly limited as long as it generates an acid upon exposure, and examples thereof include the structural unit (a0-1) and structural units (a1) to (a2) described later. As a structural unit known as a structural unit capable of forming a copolymer with other structural units, those obtained by introducing, as a substituent, an acid generator conventionally proposed for a chemically amplified resist can be used.
As the structural unit copolymerizable with the structural units (a0-1), (a1) to (a2) and the like, from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent Preferred examples include a derived structural unit, a structural unit derived from hydroxystyrene in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent.
As an acid generator conventionally proposed for a chemically amplified resist, a component (B) described later is preferable.

  As the structural unit (a0-2), those having a group represented by general formula (a0-21) or (a0-22) shown below are preferable in terms of acid strength, sensitivity, resolution, and roughness.

［式中、Ｑ^１、Ｑ^２はそれぞれ独立に単結合又は２価の連結基であり、Ｒ^３〜Ｒ^５はそれぞれ独立に有機基であり、Ｒ^４、Ｒ^５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いてもよく、Ｖ⁻は対アニオンである。Ａ⁻はアニオンを含む有機基であり、Ｍ^ｍ＋は有機カチオンであり、ｍは１〜３の整数である。］

[Wherein, Q ¹ and Q ² are each independently a single bond or a divalent linking group, R ^{3 to} R ⁵ are each independently an organic group, and R ⁴ and R ⁵ are bonded to each other to form a compound A ring may be formed together with the sulfur atom therein, and V ⁻ is a counter anion. A ⁻ is an organic group containing an anion, M ^{m +} is an organic cation, and m is an integer of 1 to 3. ]

(Structural unit having a group represented by the formula (a0-21))
In formula (a0-21), Q ¹ represents a single bond or a divalent linking group.
Examples of the divalent linking group for Q ¹ include the same divalent linking groups for R ^{2 in} the above formula (a0-1).
Among these, Q ¹ in the present invention is preferably a single bond, an ester bond [—C (═O) —O—], an ether bond (—O—), an alkylene group, or a combination thereof.

In formula (a0-21), R ^{3 to} R ⁵ are each independently an organic group.
The organic group of R ^{3 to} R ^{5 is} a group containing a carbon atom, and includes atoms other than carbon atoms (for example, hydrogen atom, oxygen atom, nitrogen atom, sulfur atom, halogen atom (fluorine atom, chlorine atom, etc.)). You may have.

The organic group for R ³ is preferably a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group include the substituents mentioned in the description of the divalent linking group in R ² . The thing similar to the bivalent hydrocarbon group which you may have is mentioned.
As the organic group for R ³ , an arylene group or an alkylene group is particularly preferable.
The arylene group for R ^3, is not particularly limited, for example, those similar to the aromatic hydrocarbon ring which is mentioned in the description of the R ² and the like. Among these, an arylene group having 6 to 20 carbon atoms is preferable, a phenylene group or a naphthylene group is more preferable, and a phenylene group is particularly preferable from the viewpoint that it can be synthesized at a low cost.
In the arylene group, part or all of the hydrogen atoms may be substituted. For example, it may or may not be substituted with an alkyl group, alkoxy group, halogen atom, hydroxyl group or the like.
The alkyl group which may be substituted with a hydrogen atom of the arylene group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Are more preferable, and a methyl group is particularly preferable.
As the alkoxy group that may be substituted for the hydrogen atom of the arylene group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, A tert-butoxy group is more preferable.
The halogen atom that may be substituted for the hydrogen atom of the arylene group is preferably a fluorine atom.

As the alkylene group for R ³ , for example, a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms can be mentioned. In the alkylene group, part or all of the hydrogen atoms are substituted. Also good. For example, it may or may not be substituted with an alkoxy group, a halogen atom, a hydroxyl group or the like. The alkoxy group and halogen atom as the substituent are the same as above.
Such an alkylene group is preferably a linear alkylene group having 1 to 5 carbon atoms from the viewpoint of excellent resolution, and specifically includes a methylene group, an ethylene group, a trimethylene group, and a tetramethylene group. Group, pentamethylene group and the like.

As the organic group for R ⁴ and R ^5, a hydrocarbon group which may have a substituent is preferable, and examples of the hydrocarbon group include those mentioned in the description of the divalent linking group in R ² . Examples thereof include monovalent monovalent hydrocarbon groups by adding one hydrogen atom to a divalent hydrocarbon group which may have a substituent.
As the organic group for R ⁴ and R ⁵ , an aryl group or an alkyl group is particularly preferable.
There is no restriction | limiting in particular as an aryl group in R < ⁴ >, R < ⁵ >, For example, the group remove | excluding one hydrogen atom from the aromatic hydrocarbon ring quoted by description of the said R < ² > is mentioned. Among these, an aryl group having 6 to 10 carbon atoms is preferable, a phenyl group or a naphthyl group is more preferable, and a phenyl group is particularly preferable from the viewpoint that it can be synthesized at a low cost.
The aryl group may have a substituent. Having a substituent means that part or all of the hydrogen atoms of the aryl group are substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, and a hydroxyl group. Is mentioned. Among these, examples of the alkyl group, alkoxy group, and halogen atom include the same alkyl groups, alkoxy groups, and halogen atoms as the substituents that the arylene group may have in the description of R ^4. .
The alkyl group for R ⁴ and R ⁵ is not particularly limited, and may be linear, branched or cyclic. 1-10 are preferable, as for carbon number of this alkyl group, 1-8 are more preferable, and 1-5 are more preferable. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. Etc. Among these, a methyl group is preferable because it is more excellent in resolution and can be synthesized at a low cost.
The alkyl group may have a substituent. Having a substituent means that part or all of the hydrogen atoms of the alkyl group are substituted with a substituent. Examples of the substituent include an alkoxy group, a halogen atom, a hydroxyl group, and an oxygen atom ( = O) and the like. Of these, examples of the alkoxy group and the halogen atom include the same alkoxy groups and halogen atoms as the substituents that the arylene group may have in the description of R ³ .

In formula (a0-21), R ⁴ and R ⁵ may be bonded to each other to form a ring together with the sulfur atom in the formula. The ring is preferably a 3- to 10-membered ring including a sulfur atom, and particularly preferably a 5- to 7-membered ring.
The ring may have a hetero atom other than the sulfur atom to which R ⁴ and R ⁵ are bonded as an atom constituting the ring skeleton. Examples of the hetero atom include a sulfur atom, an oxygen atom, and a nitrogen atom.
Specific examples of the formed ring include a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, and the like.

In formula (a0-21), V ⁻ represents a counter anion.
The counter anion of V ⁻ is not particularly limited, and for example, those conventionally known as the anion part of the onium salt acid generator can be used as appropriate.
As V ⁻ , for example, the general formula “R ^{4 ″} SO ₃ ^— (R ^{4 ″} represents a linear, branched or cyclic alkyl group, halogenated alkyl group, aryl which may have a substituent. An anion represented by a group or an alkenyl group.

In the general formula “R ^{4 ″} SO ₃ ⁻ ”, R ^{4 ″} represents a linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl which may have a substituent. Represents a group.

The linear or branched alkyl group as R ^{4 ″} preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and 1 to 4 carbon atoms. Most preferred.
The cyclic alkyl group as R ^{4 ″} preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
When R ^{4 ″} is an alkyl group, examples of “R ^{4 ″} SO ₃ ⁻ ” include methane sulfonate, n-propane sulfonate, n-butane sulfonate, n-octane sulfonate, 1-adamantane sulfonate, 2-norbornane sulfonate, Examples thereof include alkyl sulfonates such as d-camphor-10-sulfonate.

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

The aryl group as R ^{4 ″} is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group as R ^{4 ″} is preferably an alkenyl group having 2 to 10 carbon atoms.

In R ^{4 ″} , “may have a substituent” means one of hydrogen atoms in the linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group. It means that part or all may be substituted with a substituent (an atom or group other than a hydrogen atom).
The number of substituents in R ^{4 ″} may be one, or two or more.

Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, and a formula: X ³ -Q ^′ -[where Q ^′ is a divalent linking group containing an oxygen atom, and X ³ represents a substituent. It is a C3-C30 hydrocarbon group which may have. ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described above for R ^{4 ″} as the halogen atom and alkyl group in the halogenated alkyl group.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

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

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

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

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

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

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

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

[In the formula, Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ^{94 ′} — or —S—R ^{95 ′} —, wherein R ^{94 ′} and R ^{95 ′} are Each independently represents an alkylene group having 1 to 5 carbon atoms, and m is an integer of 0 or 1.]

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

In the present invention, X ³ is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, the above (L2) to (L6), (S3) to (S4), and the like.

Among the above, the R ^{4 "is,} X ³ -Q ^'as a halogenated alkyl group or a substituted group, - it is preferable to have a.
^'- if having, as the ^{R 4 ", X 3 -Q'} -Y 3 - X 3 -Q as a substituent in the Formula, Q ^{'and X 3} are as defined above, the ^{Y 3} substituent A C1-C4 alkylene group which may have or a C1-C4 fluorinated alkylene group which may have a substituent.] Is preferable.
X ³ -Q ^{'-Y 3} - In the group represented by the formula, the alkylene group of ^{Y 3,} wherein ^Q' include the same ones having 1 to 4 carbon atoms of the alkylene groups listed.
Examples of the fluorinated alkylene group include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^3, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH _{(CH 3) -, - C} (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

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

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

-SO ₃ - ^"R 4 is a group represented by ^{X 3 -Q '-Y 3" -} R 4 As specific examples of, for example represented by any one of the following formulas (b1) ~ (b9) Anions.

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

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

As the substituent for R ^7, the substituent that the aliphatic hydrocarbon group may have and the substituent that the aromatic hydrocarbon group may have in R ² in the formula (a0-1) The thing similar to what was mentioned as is mentioned.
Code (r1 and r2, W1 to W6) attached to R ⁷ when is an integer of 2 or more, a plurality of the ^{R 7} groups may be the same, respectively, may be different.

Examples of V ⁻ in the formula (a0-21) include an anion represented by the following general formula (b-3) and an anion represented by the following general formula (b-4).

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

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

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

V in the formula (a0-21) ^- as represented by the general formula ^"R 4" SO ₃ ^- "represented by anions (especially in, ^{R 4"} is ^{X 3} -Q ^'-Y 3 - is a group represented by The anions represented by the above formulas (b1) to (b9) are preferred.

  Specific examples of the group represented by formula (a0-21) are shown below.

  In the present invention, the structural unit having the group represented by the formula (a0-21) (hereinafter referred to as “structural unit (a0-21)”) is represented by the following formula (a0-21-1). Are preferred.

［式中、Ｒ、Ｑ^１、Ｒ^３〜Ｒ^５、Ｖ⁻は前記同様である。］

[Wherein, R, Q ¹ , R ^{3 to} R ⁵ and V ⁻ are the same as described above. ]

(Structural unit having a group represented by the formula (a0-22))
In formula (a0-22), Q ² represents a single bond or a divalent linking group. Examples of the divalent linking group for Q ² include the same divalent linking groups for R ^{2 in} the above formula (a0-1). Among them, Q ² in the present invention is a single bond, a linear / branched alkylene group, an ester bond [—C (═O) —O—], —NH— or a combination thereof. It is preferable.

In formula (a0-22), A ⁻ represents an organic group containing an anion.
A ⁻ is not particularly limited as long as it includes a site which is generated by exposure and becomes an acid anion, but is not limited thereto. A group capable of generating an imide anion or a tris (alkylsulfonyl) methide anion is preferred.
Among them, A ^- as represented by the following formula (a0-2-an1), a group represented by (a0-2-an2) preferred.

［式中、Ｒ^ｆ１及びＲ^ｆ２はそれぞれ独立に水素原子、アルキル基、フッ素原子、又はフッ素化アルキル基であり、Ｒ^ｆ１、Ｒ^ｆ２のうち少なくとも１つはフッ素原子又はフッ素化アルキル基であり、ｐ０は１〜８の整数である。Ｙ^１”はフッ素原子で置換されていてもよい炭化水素基であり、Ｚ^１”はフッ素原子で置換されていてもよい炭化水素基であり、Ｙ^１”またはＺ^１”のいずれか１つは少なくとも１つのフッ素原子を有するものとする。］

[Wherein, R ^f1 and R ^f2 each independently represent a hydrogen atom, an alkyl group, a fluorine atom, or a fluorinated alkyl group, and at least one of R ^f1 and R ^f2 is a fluorine atom or a fluorinated alkyl group. , P0 is an integer of 1-8. Y ¹ ″ is a hydrocarbon group that may be substituted with a fluorine atom, Z ¹ ″ is a hydrocarbon group that may be substituted with a fluorine atom, and one of Y ¹ ″ and Z ¹ ″ Has at least one fluorine atom. ]

In formula (a0-2-an1), R ^f1 and R ^f2 each independently represent a hydrogen atom, an alkyl group, a fluorine atom, or a fluorinated alkyl group, and at least one of R ^f1 and R ^f2 is fluorine. An atom or a fluorinated alkyl group.
As the alkyl group for R ^f1 and R ^f2 , an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group Group, pentyl group, isopentyl group, neopentyl group and the like.
Examples of the fluorinated alkyl group of ^{R f1,} R ^f2, group in which part or all of the hydrogen atoms of the alkyl group of the ^{R f1, R f2} is substituted with a fluorine atom is preferred.
R ^f1 and R ^f2 are preferably a fluorine atom or a fluorinated alkyl group.
In formula (a0-2-an1), p0 is an integer of 1 to 8, preferably an integer of 1 to 4, and more preferably 1 or 2.

In the formula (a0-2-an2), the hydrocarbon group represented by Y ¹ ″ includes a group obtained by further removing one hydrogen atom of the hydrocarbon group mentioned in the above X ³ (that is, a divalent hydrocarbon group). Preferably, it is an alkylene group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group is preferably linear or branched, and the number of carbon atoms is 1 to 10. It is more preferably 7, and further preferably ^{1 to} _3. Among them, Y ¹ ″ is particularly preferably —CF ₂ —.
Z 1 ^"hydrocarbon group are the same as the hydrocarbon groups listed above X ^3, preferably at least one alkyl group having 1 to 10 carbon atoms in which a hydrogen atom is substituted with a fluorine atom .Z ^1" The alkyl group is preferably linear or branched, and more preferably has 1 to 7 carbon atoms, and still more preferably has 1 to 3 carbon atoms. Among these, as Z ¹ ″, —CF ₃ is particularly preferable.
It is preferred that any ^{one of} Y ¹ ″ or Z ¹ ″ has at least one fluorine atom, and both contain a fluorine atom.

In formula (a0-2), M ^{m +} is a counter cation, and m is an integer of 1 to 3.
The counter counter cation of M ^{m +} is not particularly limited. For example, it is known as a cation moiety such as a photodegradable base conventionally used for a quencher of a resist composition or an onium-based acid generator of a resist composition. The organic cation that has been used can be used.
In the present invention, the counter cation of M ^{m +} is preferably an onium cation, and specific examples include a sulfonium cation, an iodonium cation, a phosphonium cation, a diazonium cation, an ammonium cation, and a pyridinium cation.
Among them, as the counter cation of M ^{m +} , cations represented by the following general formulas (c-1) and (c-2) can be preferably used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；式（ｃ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよい。］

^{Wherein, R 1 "~R 3",} R 5 "~R 6" each independently represents an aryl group or an alkyl group; one of ^R 1 ^{"~R 3"} in the formula (c-1), Any two may be bonded to each other to form a ring together with the sulfur atom in the formula. ]

In formula (c-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group. In addition, any two of R ¹ ″ to R ³ ″ in formula (c-1) may be bonded to each other to form a ring together with the sulfur atom in the formula.
Moreover, it is preferable that at least one of R ¹ ″ to R ³ ″ represents an aryl group. Among R ¹ "~R ^3", more preferably 2 or more is an aryl ^group, all of R 1 "~R ^3" is most preferably an aryl group.

The aryl group and alkyl group of R ¹ ″ to R ³ ″ are the same as the aryl group and alkyl group of R ^{4 to} R ⁵ described above.
Preferable examples of the cation moiety represented by the formula (c-1) include cations represented by the following formulas (c-1-1) to (c-1-32).

In the formulas (c-1-19) and (c-1-20), R ⁵⁰ is a group containing an acid dissociable, dissolution inhibiting group, and the formula (p1), (p1-1) or (p2) described later ) Or an oxygen atom of —R ⁹¹ —C (═O) —O—, the formulas (1-1) to (1-9) or (2-1) to (2- 6) is preferably a bonded group. Here, R ⁹¹ is a single bond or a linear or branched alkylene group, and the alkylene group preferably has 1 to 5 carbon atoms.

In the formula (c-1-21), W is a divalent linking group, and examples thereof include the same as the divalent linking group for R ² in the formula (a0-1). It is preferably a linear or branched alkylene group, a divalent cyclic aliphatic hydrocarbon group, or a divalent linking group containing a hetero atom, and is a linear or branched alkylene group. It is more preferable that it is a linear alkylene group.

In the above formula (c-1-22), R ^f is a fluorinated alkyl group, and is a group in which part or all of the hydrogen atoms of the unsubstituted alkyl group are substituted with fluorine atoms. As this unsubstituted alkyl group, a linear or branched alkyl group is preferable, and a linear alkyl group is more preferable.

In formula (c-1-23), Q is a divalent linking group, and R ⁵¹ is an organic group having a carbonyl group, an ester bond, or a sulfonyl group.
Examples of the divalent linking group for Q include the same divalent linking groups as those described above for R ² in formula (a0-1), and the divalent linking group includes an alkylene group and an ester bond. Among them, an alkylene group, —R ⁷⁷ —C (═O) —O—R ⁷⁸ — [R ⁷⁷ , R ⁷⁸ are each independently an alkylene group. ] Is more preferable.
R ⁵¹ is an organic group having a carbonyl group, an ester bond, or a sulfonyl group, and the organic group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Examples of the aromatic hydrocarbon group and the aliphatic hydrocarbon group include those similar to X ³ described later. Among them, the organic group having a carbonyl group, an ester bond or a sulfonyl group of R ⁵¹ is preferably an aliphatic hydrocarbon group, more preferably a bulky aliphatic hydrocarbon group, and a cyclic saturated carbonization. More preferably, it is a hydrogen group. R ⁵¹ is preferably bonded to the groups represented by the above (L1) to (L6) and (S1) to (S4), the same group as X ³ , a monocyclic group or a polycyclic group. And a group in which a hydrogen atom is substituted with an oxygen atom (═O).

In the formulas (c-1-24) and (c-1-25), R ⁵² is an alkyl group having 4 to 10 carbon atoms that is not an acid dissociable group. As R ⁵² , a linear or branched alkyl group is preferable, and a linear alkyl group is more preferable.

In the formula (c-1-26), R ⁵³ is a divalent group having a base dissociable site, R ⁵⁴ is a divalent linking group, and R ⁵⁵ is a group having an acid dissociable group. .
Here, the base dissociable part of R ⁵³ refers to a part dissociated by the action of an alkali developer (specifically, a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C.). Dissociation of the base dissociable portion increases solubility in an alkali developer. The alkali developer may be one generally used in the lithography field. The base dissociable portion is preferably dissociated at 23 ° C. by the action of a 2.38 mass% tetramethylammonium hydroxide aqueous solution.
R ⁵³ may be a group composed only of a base dissociable site, or may be a group composed of a base dissociable site and a group or atom that is not dissociated by a base.
As the base dissociable portion of R ⁵³ , an ester bond (—C (═O) —O—) is most preferable.
Examples of the group or atom that R ⁵³ does not dissociate with a base include, for example, the same divalent linking group as R ² in formula (a0-1), or a combination of these linking groups (however, Excluding those that dissociate). Here, the “combination of linking groups” refers to a divalent group formed by bonding of linking groups. Of these, a combination of an alkylene group and a divalent linking group containing a hetero atom is preferable. However, the heteroatom is preferably not adjacent to an atom whose bond is broken by the action of the base in the base dissociable portion.
The alkylene group is the same as the linear or branched alkylene group in the description of R ² in the formula (a0-1).
The heteroatom is particularly preferably an oxygen atom.
Among the above, R ⁵³ is preferably a group composed of a base dissociable portion and a group or atom that is not dissociated by a base.

R ⁵⁴ is a divalent linking group, and examples thereof include the same as the divalent linking group for R ² in formula (a0-1). Of these, an alkylene group or a divalent aliphatic cyclic group is preferable, and an alkylene group is particularly preferable.
R ⁵⁵ is a group having an acid dissociable group.
Here, the acid dissociable group is an organic group that can be dissociated by the action of an acid, and is not particularly limited as long as it is such as, for example, until now, acid dissociation of a base resin for a chemically amplified resist And those proposed as soluble dissolution inhibiting groups. Specifically, it is the same as the acid dissociable, dissolution inhibiting group described in the structural unit (a1) described later, and is a cyclic or chain tertiary alkyl ester type acid dissociable group; an acetal type acid dissociation such as an alkoxyalkyl group A tertiary alkyl ester type acid dissociable group is preferable among them.
Further, the group having an acid dissociable group may be an acid dissociable group itself, an acid dissociable group, a group or an atom not dissociated by an acid (bonded to an acid generator even after the acid dissociable group is dissociated). Or a group formed by bonding to an as-is group or atom). Here, examples of the group or atom that does not dissociate with an acid include the same groups as the divalent linking group for R ² in the formula (a0-1).

In Formula (c-1-27), W ² is a single bond or a divalent linking group, t is 0 or 1, and R ⁶² is a group that is not dissociated by an acid (hereinafter referred to as “acid non-dissociable group”). It is said.)
Examples of the divalent linking group for W ² include the same divalent linking groups for R ² in formula (a0-1). Among these, W ² is preferably a single bond.
t is preferably 0.
The acid non-dissociable group for R ⁶² is not particularly limited as long as it is a group that does not dissociate by the action of an acid, but is preferably a hydrocarbon group that does not dissociate by an acid and may have a substituent. A cyclic hydrocarbon group which may have a group is more preferable, and a group obtained by removing one hydrogen atom from adamantane is further preferable.

In the formula (c-1-28) and the formula (c-1-29), R ⁹ and R ¹⁰ are each independently a phenyl group, a naphthyl group, or a carbon number of 1 to 1 which may have a substituent. 5 is an alkyl group, an alkoxy group, or a hydroxyl group, u is an integer of 1 to 3, and 1 or 2 is most preferable.
In formula (c-1-29), R ⁶¹ and R ⁶² are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and preferably a hydrogen atom or a methyl group.

In the formula (c-1-30), Y ¹⁰ represents an acid dissociable group that can be dissociated by the action of an acid; R ⁵⁶ and R ⁵⁷ each independently represent a hydrogen atom, an alkyl group, or an aryl group; R ⁵⁶ and R ⁵⁷ may be bonded to each other to form a ring; Y ¹¹ and Y ¹² each independently represent an alkyl group or an aryl group, and Y ¹¹ and Y ¹² are bonded to each other to form a ring. It may be formed.
Y ¹⁰ includes a group that forms a tertiary alkyl ester with —C (R ⁵⁶ ) (R ⁵⁷ ) —C (═O) —O—.
The term “tertiary alkyl ester” as used herein means that the tertiary carbon atom of Y ¹⁰ is bonded to the terminal oxygen atom of —C (R ⁵⁶ ) (R ⁵⁷ ) —C (═O) —O—. Shows the structure. In this tertiary alkyl ester, when an acid acts, the bond is broken between the oxygen atom and the tertiary carbon atom.
Examples of Y ¹⁰ include an aliphatic branched acid dissociable group and an acid dissociable group containing an aliphatic cyclic group.
Here, “aliphatic branched” means having a branched structure having no aromaticity. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
Examples of the aliphatic branched acid dissociable group include a group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ). ^Wherein, R 71 ^{to R 73} each independently represents a linear alkyl group of 1 to 5 carbon atoms. The group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ) preferably has 4 to 8 carbon atoms, specifically a tert-butyl group or a 2-methyl-2-butyl group. , 2-methyl-2-pentyl group, 3-methyl-3-pentyl group and the like. A tert-butyl group is particularly preferable.

Examples of the “aliphatic cyclic group” include a monocyclic group or a polycyclic group having no aromaticity, and a polycyclic group is preferable.
Such an “aliphatic cyclic group” may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, and an oxygen atom (= O).
Examples of the aliphatic cyclic group include a monocycloalkane which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group; bicycloalkane, tricyclo Examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as an alkane or tetracycloalkane. More specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. . Y ¹⁰ is a cyclic hydrocarbon group having 5 or more carbon atoms and is an acid dissociable group that can be dissociated by the action of an acid, so that resolution, LWR, exposure margin (EL margin), resist pattern shape, etc. This is particularly preferable because the lithography properties of the film become good.

R ⁵⁶ and R ⁵⁷ each independently represent a hydrogen atom, an alkyl group or an aryl group.
^Examples of the alkyl group or aryl group for R ⁵⁶ and R ⁵⁷ are the same as the alkyl group or aryl group for R ¹ ″ to R ³ ″. Further, R ⁵⁶ and R ⁵⁷ may be bonded to each other to form a ring in the same manner as R ¹ ″ to R ³ ″. Among the above, R ⁵⁶ and R ⁵⁷ are both hydrogen atoms. It is particularly preferred.

Y ¹¹ and Y ¹² each independently represents an alkyl group or an aryl group.
Examples of the alkyl group or aryl group for Y ¹¹ and Y ¹² are the same as the alkyl group or aryl group for R ¹ ″ to R ³ ″.
Among these, Y ¹¹ and Y ¹² are particularly preferably each a phenyl group or a naphthyl group. Y ¹¹ and Y ¹² may be bonded to each other to form a ring in the same manner as R ¹ ″ to R ³ ″.

In the formula (c-1-31), R ⁵⁸ is an aliphatic cyclic group; R ⁵⁹ is a single bond or an alkylene group which may have a substituent; R ⁶⁰ is a substituent. R ⁶¹ is an alkylene group having 4 or 5 carbon atoms which may have a substituent.
The aliphatic cyclic group for R ⁵⁸ may be a monocyclic group or a polycyclic group, but is preferably a polycyclic group, and includes one or more polycycloalkanes. A group in which a hydrogen atom is removed is preferred, and a group in which one or more hydrogen atoms are removed from adamantane is most preferred.
The alkylene group which may have a substituent R ^59, preferably a linear or branched alkylene group, and among them, a single bond, or preferably an alkylene group having 1 to 3 carbon atoms.
The arylene group for R ⁶⁰ preferably has 6 to 20 carbon atoms, more preferably 6 to 14 carbon atoms, and still more preferably 6 to 10 carbon atoms. Examples of such an arylene group include a phenylene group, a biphenylene group, a fluorenylene group, a naphthylene group, an anthrylene group, and a phenanthrylene group, and a phenylene group and a naphthylene group are preferable because they can be synthesized at low cost.

In the formula (c-1-32), R ⁰¹ is an arylene group or an alkylene group, R ⁰² and R ⁰³ are each independently an aryl group or an alkyl group, and R ⁰² and R ⁰³ are bonded to each other. And a sulfur atom in the formula may form a ring, at least one of R ^{01 to} R ⁰³ is an arylene group or an aryl group, W ¹ is an n ″ -valent linking group, and n ″ is 2 or 3.
The arylene group R ^01, not particularly limited, for example, an arylene group having 6 to 20 carbon atoms, said arylene groups, part or all of the hydrogen atoms, those may be substituted The alkylene group represented by R ⁰¹ is not particularly limited, and examples thereof include linear, branched or cyclic alkylene groups having 1 to 10 carbon atoms.
The aryl group for R ⁰² and R ⁰³ is not particularly limited, and may be, for example, an aryl group having 6 to 20 carbon atoms, and the aryl group may have part or all of its hydrogen atoms substituted. There are no particular restrictions on the alkyl group of R ⁰² and R ⁰³ , and examples include linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms.
Examples of the divalent linking group for W ¹ include the same divalent linking groups as those described above for Y ²² , which may be linear, branched or cyclic, and cyclic. preferable. Of these, a group in which two carbonyl groups are combined at both ends of the arylene group is preferable.
The trivalent linking group for W ¹ is preferably a group in which three carbonyl groups are combined with an arylene group.

In the formula (c-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferable that all of R ⁵ ″ to R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Among these, it is most preferable that R ⁵ ″ to R ⁶ ″ are all phenyl groups.

Moreover, as an organic cation of Mm ^+, the organic cation represented by the following general formula (c-3) is also mentioned.

［式中、Ｒ^４４〜Ｒ^４６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_４’〜ｎ_５’はそれぞれ独立して０〜３の整数であり、ｎ_６’は０〜２の整数である。］

[Wherein R ^{44 to} R ⁴⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n ₄ ′ to n ₅ ′ are each independently 0 to 3; N ₆ ′ is an integer of 0 to 2. ]

In R ⁴⁴ to R ^46, the alkyl group is preferably an alkyl group of 1 to 5 carbon atoms, more preferably an linear or branched alkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl radical, n A butyl group or a tert-butyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n ₄ ′ to n ₆ ′ attached to R ^{44 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{44 to} R ⁴⁶ may be the same or different.
n ₄ ′ is preferably 0 to 2, and more preferably 0 or 1.
n ₅ ′ is preferably 0 or 1, and more preferably 0.
n ₆ ′ is preferably 0 or 1, more preferably 1.
Especially, the cation represented by the said formula (c-1)-(c-3) is preferable, and the cation represented by the said formula (c-1-1)-(c-1-32) is more preferable.

  In the present invention, the structural unit having a group represented by the formula (a0-21) (hereinafter referred to as “structural unit (a0-21)”) is represented by the following formulas (a0-2-11) to (a0−). 2-13) and structural units selected from the group consisting of groups represented by (a0-2-21) to (a0-2-23) are preferred.

［式中、Ｒ、Ｒ^ｆ１、Ｒ^ｆ２、ｐ０、（Ｍ^ｍ＋）_１／ｍは前記同様であり、Ｑ^２１はそれぞれ独立に単結合又は２価の連結基である。Ｑ^２２は２価の連結基である。Ｑ^２３は−Ｏ−、−ＣＨ_２−Ｏ−、又は−Ｃ（＝Ｏ）−Ｏ−を含有する基である。Ｒ^ｑ１はフッ素原子又はフッ素化アルキル基である。Ｒ^ｎは水素原子又は炭素数１〜５のアルキル基である。］

[Wherein, R, R ^f1 , R ^f2 , p0, (M ^{m +} ) _{1 / m} are the same as described above, and Q ²¹ each independently represents a single bond or a divalent linking group. Q ²² is a divalent linking group. Q ²³ is a group containing —O—, —CH ₂ —O—, or —C (═O) —O—. R ^q1 is a fluorine atom or a fluorinated alkyl group. R ⁿ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ]

［式中、Ｒ、Ｑ^２１〜Ｑ^２３、Ｒ_ｎ、Ｒ^ｑ１、Ｙ^１”、Ｚ^１”、（Ｍ^ｍ＋）_１／ｍは前記同様である。］

[Wherein, R, Q ^{21 to} Q ²³ , R _n , R ^q1 , Y ¹ ″, Z ¹ ″, (M ^{m +} ) _{1 / m} are the same as described above. ]

In formulas (a0-2-11) to (a0-2-13), R, R ^f1 , R ^f2 , p0, (M ^{m +} ) _{1 / m} are the same as described above, and Q ²¹ is a single bond or a divalent group. The linking group of Examples of the divalent linking group for Q ²¹ include the same divalent linking groups for R ² in formula (a0-1). Among these, Q ²¹ is preferably a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a divalent linking group containing a hetero atom, which is mentioned for R ^2. A linear or branched alkylene group, a combination of a linear or branched alkylene group and a divalent linking group containing a hetero atom, a divalent containing a cyclic aliphatic hydrocarbon group and a hetero atom And a combination of an aromatic hydrocarbon group and a divalent linking group containing a hetero atom are more preferable; a linear or branched alkylene group, a linear or branched alkylene group And a combination of an ester bond [—C (═O) —O—], a combination of a divalent alicyclic hydrocarbon group and an ester bond [—C (═O) —O—] is particularly preferred; Straight or branched alkylene groups, or straight Jo or branched alkylene group and an ester bond [-C (= O) -O-] combination with the most preferred.

Wherein ^{(a0-2-12), Q 22} represents a divalent linking group, the same groups as those divalent linking group for ^{R 2} in the formula (a0-1), among others, ^{R 2} It is preferably a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, or a divalent aromatic hydrocarbon group mentioned in the above, particularly preferably a linear alkylene group, a methylene group or Most preferred is an ethylene group.
In formula (a0-2-12), R ⁿ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. As a C1-C5 alkyl group, the same thing as the C1-C5 alkyl group of said R is mentioned. Of these, R ⁿ is preferably a hydrogen atom or a methyl group.

In formula (a0-2-13), Q ²³ represents a group containing —O—, —CH ₂ —O—, or —C (═O) —O—.
Q ²³ is specifically a group consisting of —O—, —CH ₂ —O—, or —C (═O) —O—; —O—, —CH ₂ —O— or —C (═O). And a group composed of —O— and a divalent hydrocarbon group which may have a substituent.
The divalent hydrocarbon group which may have such a substituent is a divalent hydrocarbon which may have a substituent in the divalent linking group of R ² in formula (a0-1). The same thing as a group is mentioned. Among them, the “divalent hydrocarbon group” in Q ¹ is preferably an aliphatic hydrocarbon group, and more preferably a linear or branched alkylene group.
Q ²³ is preferably a group consisting of —C (═O) —O— and a divalent hydrocarbon group which may have a substituent, and —C (═O) —O— and aliphatic carbonization. A group consisting of a hydrogen group is more preferred, and a group consisting of —C (═O) —O— and a linear or branched alkylene group is more preferred.
Specific examples suitable for Q ^23, in particular, a group represented by the following general formula ^(Q 23 -1).

［式（Ｑ^２３−１）中、Ｒ^ｑ２及びＲ^ｑ３はそれぞれ独立に水素原子、アルキル基又はフッ素化アルキル基であり、互いに結合して環を形成していてもよい。］

[In Formula (Q ²³ -1), R ^q2 and R ^q3 each independently represent a hydrogen atom, an alkyl group, or a fluorinated alkyl group, and may be bonded to each other to form a ring. ]

In the formula (Q ²³ -1), the alkyl group in R ^q2 and R ^q3 may be linear, branched or cyclic, and is preferably linear or branched.
In the case of a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 5, more preferably an ethyl group or a methyl group, and particularly preferably an ethyl group.
In the case of a cyclic alkyl group, the number of carbon atoms is preferably 4 to 15, more preferably 4 to 12, and most preferably 5 to 10. Specific examples include monocycloalkanes; groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. It is done. Of these, a group in which one or more hydrogen atoms have been removed from adamantane is preferable.

The fluorinated alkyl group for R ^q2 and R ^q3 is a group in which part or all of the hydrogen atoms in the alkyl group are substituted with fluorine atoms.
In the fluorinated alkyl group, the alkyl group not substituted with a fluorine atom may be linear, branched or cyclic, and the same as the above-mentioned “alkyl group in R ^q2 and R ^q3 ”. Can be mentioned.

R ^q2 and R ^q3 may be bonded to each other to form a ring, and the ring formed by R ^q2 and R ^q3 and the carbon atom to which they are bonded includes a monocyclo group in the cyclic alkyl group. The thing remove | excluding two hydrogen atoms from alkane or polycycloalkane can be illustrated, It is preferable that it is a 4-10 membered ring, and it is more preferable that it is a 5-7 membered ring.

Among the above, R ^q2 and R ^q3 are preferably a hydrogen atom or an alkyl group.

In formula (a0-2-13), R ^q1 represents a fluorine atom or a fluorinated alkyl group.
In the fluorinated alkyl group for R ^q1 , the alkyl group that is not substituted with a fluorine atom may be linear, branched, or cyclic.
In the case of a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 5, more preferably 1 to 3, and particularly preferably 1 to 2. .
In the case of a cyclic alkyl group, the number of carbon atoms is preferably 4 to 15, more preferably 4 to 12, and still more preferably 5 to 10. Specific examples include monocycloalkanes; groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, examples include monocycloalkanes such as cyclopentane and cyclohexane; groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. .
In the fluorinated alkyl group, the ratio of the number of fluorine atoms to the total number of fluorine atoms and hydrogen atoms contained in the fluorinated alkyl group (fluorination rate (%)) is preferably 30 to 100%. 50 to 100% is more preferable. The higher the fluorination rate, the higher the hydrophobicity of the resist film.
Among the above, R ^q1 is preferably a fluorine atom.

In formulas (a0-2-21) to (a0-2-23), R, Q ^{21 to} Q ²³ , R _n , R ^q1 , Y ¹ ″, Z ¹ ″, (M ^{m +} ) _{1 / m} are the same as above. It is.

Specific examples of the structural unit (a0-22) are shown below. In the following formulas, R ^α is a hydrogen atom, a methyl group or a trifluoromethyl group, and (M ^{m +} ) _{1 / m} is the same as described above.

The structural unit (a0-2) contained in the component (A1) may be one type or two or more types.
In the component (A1), the proportion of the structural unit (a0-2) is preferably 1 to 40 mol%, more preferably 1 to 35 mol%, based on the total of all structural units constituting the component (A1). Preferably, 3-30 mol% is more preferable, and 5-25 mol% is especially preferable.
By setting the proportion of the structural unit (a0-2) to be equal to or higher than the lower limit value, the effects (resolution, lithography characteristics, pattern shape improvement effect) by including the structural unit (a0-2) can be sufficiently obtained. By setting it to the upper limit value or less, it becomes easy to balance with other structural units.

(Structural unit (a1))
In addition to the structural units (a0-1) and (a0-2), the component (A1) further contains a structural unit (a1) containing an acid-decomposable group that increases in polarity by the action of an acid. It is preferable.
The “acid-decomposable group” is at least in the structure of the acid-decomposable group by the action of an acid generated from the structural unit (a0-2) or an optional acid generator component (B) described later by exposure. It is an acid-decomposable group that can be partially cleaved.
Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (—SO ₃ H), and the like. Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include a group in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).
The “acid-dissociable group” means at least the acid-dissociable group and the acid by the action of an acid generated from the structural unit (a0-2) or an optional acid generator component (B) described later by exposure. It is a group having acid dissociation property that can break a bond between atoms adjacent to the dissociable group. 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 polymer increases. As the polarity increases, the solubility in the developer changes relatively. When the developer is an alkaline developer, the solubility increases. On the other hand, the developer contains an organic solvent (organic type). In the case of a developer, the solubility decreases.

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

Examples of the tertiary alkyl ester type acid dissociable group include an aliphatic branched acid dissociable group and an acid dissociable group containing an aliphatic cyclic group.
Here, “aliphatic branched” means having a branched structure having no aromaticity. The structure of the “aliphatic branched acid dissociable group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
Examples of the aliphatic branched acid dissociable group include a group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ). In the formula, R ^{71 to} R ⁷³ are the same as described above.

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The aliphatic cyclic group in the “acid-dissociable group containing an aliphatic cyclic group” may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, and an oxygen atom (= O).
The basic ring structure excluding the substituent of the aliphatic cyclic group is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The hydrocarbon group may be either saturated or unsaturated, but is usually preferably saturated.
The aliphatic cyclic group may be monocyclic or polycyclic.
As the aliphatic cyclic group, those having 3 to 30 carbon atoms are preferable, those having 5 to 30 are more preferable, 5 to 20 are more preferable, 6 to 15 are particularly preferable, and 6 to 12 is most preferable. . As the monocyclic aliphatic cyclic group, a group in which one or more hydrogen atoms have been removed from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclobutane, cyclopentane, and cyclohexane. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like. Moreover, a part of carbon atoms constituting the ring of these aliphatic cyclic groups may be substituted with an ether group (—O—).

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

［式中、Ｒ^１４はアルキル基であり、ｇは０〜８の整数である。］

[Wherein, R ¹⁴ represents an alkyl group, and g represents an integer of 0 to 8. ]

［式中、Ｒ^１５およびＲ^１６は、それぞれ独立してアルキル基である。］

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

In formulas (1-1) to (1-9), the alkyl group of R ¹⁴ may be linear, branched or cyclic, and is preferably linear or branched.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and still more preferably 1 or 2. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group and the like, and isopropyl group is most preferable.
g is preferably an integer of 0 to 3, more preferably an integer of 1 to 3, and still more preferably 1 or 2.
In formulas (2-1) to (2-6), examples of the alkyl group for R ^{15 to} R ¹⁶ include the same alkyl groups as those described above for R ¹⁴ .
In the formulas (1-1) to (1-9) and (2-1) to (2-6), a part of the carbon atoms constituting the ring is substituted with an etheric oxygen atom (—O—). May be.
In formulas (1-1) to (1-9) and (2-1) to (2-6), a hydrogen atom bonded to a carbon atom constituting the ring may be substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, and a fluorinated alkyl group.

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

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

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

In formula (p1), n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the alkyl group for R ¹ ′ and R ² ′ include the same alkyl groups listed as the substituents that may be bonded to the α-position carbon atom in the description of the α-substituted acrylate ester. A methyl group or an ethyl group is preferred, and a methyl group is most preferred.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同じである。］

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

Examples of the alkyl group for Y include the same alkyl groups as those described above for the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylate ester.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as the aliphatic cyclic groups mentioned in “Acid-dissociable groups containing formula groups”.

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

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

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

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

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

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

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

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

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

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

In the general formula (a11-0-1), the alkyl group and the halogenated alkyl group of R are each exemplified as the substituent which may be bonded to the α-position carbon atom in the description of the α-substituted acrylate ester. And the same alkyl groups and halogenated alkyl groups. 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 most preferably a hydrogen atom or a methyl group.
X ¹ is not particularly limited as long as it is an acid dissociable group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable groups, acetal type acid dissociable groups, and the like. An ester type acid dissociable group is preferred.
In general formula (a11-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a11-0-1).

Examples of the divalent linking group for Y ² include the same divalent linking groups for R ² in formula (a0-1).
Among these, the divalent linking group for Y ² is particularly preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom. Among these, a linear or branched alkylene group or a divalent linking group containing a hetero atom is preferable.

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

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

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

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

In the present invention, as the structural unit (a11), a structural unit represented by the following general formula (a11-0-11), a structural unit represented by the following general formula (a11-0-12), and the following general formula ( a11-0-13), a structural unit represented by the following general formula (a11-0-14), a structural unit represented by the following general formula (a11-0-15), and the following general unit It is preferable to have at least one selected from the group consisting of structural units represented by formula (a11-0-2).
Among them, the structural unit represented by the following general formula (a11-0-11), the structural unit represented by the following general formula (a11-0-12), and the following general formula (a11-0-13) A structural unit represented by the following general formula (a11-0-14) and at least one selected from the group consisting of the structural unit represented by the following general formula (a11-0-15) It is more preferable.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒ^８１はアルキル基であり；Ｒ^８２は、当該Ｒ^８２が結合した炭素原子と共に脂肪族単環式基を形成する基であり；Ｒ^８３は分岐鎖状のアルキル基であり；Ｒ^８４は、当該Ｒ^８４が結合した炭素原子と共に脂肪族多環式基を形成する基であり；Ｒ^８５は炭素数１〜５の直鎖状のアルキル基である。Ｒ^１５およびＲ^１６は、それぞれ独立してアルキル基である。Ｙ^２は２価の連結基であり、Ｘ^２は酸解離性基である。］

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ⁸¹ is an alkyl group; R ⁸² is a carbon to which R ⁸² is bonded. A group that forms an aliphatic monocyclic group with an atom; R ⁸³ is a branched alkyl group; and R ⁸⁴ is a group that forms an aliphatic polycyclic group together with the carbon atom to which R ⁸⁴ is bonded. R ⁸⁵ is a linear alkyl group having 1 to 5 carbon atoms. R ¹⁵ and R ¹⁶ are each independently an alkyl group. Y ² is a divalent linking group, and X ² is an acid dissociable group. ]

In each formula, the description of R, Y ² and X ² is the same as described above.
In formula (a11-0-11), examples of the alkyl group for R ⁸¹ include the same alkyl groups as those described above for R ¹⁴ in formulas (1-1) to (1-9). Group or isopropyl group is preferred.
R ⁸² is, the aliphatic monocyclic group formed together with the carbon atom to which R ⁸² is bonded, the same aliphatic cyclic groups as those in the aforementioned tertiary alkyl ester-type acid dissociable groups, a monocyclic group The thing similar to what is is mentioned. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably a 3- to 11-membered ring, more preferably a 3- to 8-membered ring, further preferably a 4- to 6-membered ring, and particularly preferably a 5- or 6-membered ring.
In the monocycloalkane, a part of carbon atoms constituting the ring may or may not be substituted with an ether group (—O—).
Moreover, this monocycloalkane may have a C1-C5 alkyl group, a fluorine atom, or a C1-C5 fluorinated alkyl group as a substituent.
Examples of R ⁸² constituting the aliphatic monocyclic group include a linear alkylene group in which an ether group (—O—) may be interposed between carbon atoms.

Specific examples of the structural unit represented by the formula (a11-0-11) include the formulas (a1-1-16) to (a1-1-23), (a1-1-27), and (a1-1 -31). Among these, the formulas (a1-1-16) to (a1-1-17), (a1-1-20) to (a1-1-23), (a1-1-27), (a1-1-1- The structural unit represented by the following (a11-1-02) including the structural units represented by 31), (a1-1-32), and (a1-1-33) is preferable. Moreover, the structural unit represented by the following (a11-1-02 ′) is also preferable.
In each formula, h is an integer of 1 to 4, and 1 or 2 is preferable.

［式中、Ｒ、Ｒ^８１はそれぞれ前記と同じであり、ｈは１〜４の整数である。］

[Wherein, R and R ⁸¹ are the same as defined above, and h is an integer of 1 to 4. ]

Wherein ^(A11-0-12), as the branched alkyl group ^{R 83,} the alkyl of the formula (1-1) to (1-9) branched chain mentioned by an alkyl group ^{R 14} in Examples thereof are the same as those described above, and an isopropyl group is most preferable.
R ⁸⁴ is, the aliphatic polycyclic group formed together with the carbon atom to which R ⁸⁴ is bonded, the same aliphatic cyclic groups as those in the aforementioned tertiary alkyl ester-type acid dissociable group, polycyclic group The thing similar to what is is mentioned.
Specific examples of the structural unit represented by the formula (a11-0-12) include those represented by the formulas (a1-1-26) and (a1-1-28) to (a1-1-30). Units are listed.
The constitutional unit represented by formula ^{(a11-0-12), R 84} is preferably the aliphatic polycyclic group which forms together with the carbon atom to which ^{R 84} is bonded is a 2-adamantyl group, especially The structural unit represented by the formula (a1-1-26) is preferable.

In formula (a11-0-13), R and R ⁸⁴ are the same as defined above.
As the linear alkyl group for R ^85, the same linear alkyl groups as those described above for the alkyl group for R ¹⁴ in formulas (1-1) to (1-9) can be used, and methyl Most preferred are groups or ethyl groups.
Specific examples of the structural unit represented by the formula (a11-0-13) include formulas (a1-1-1) to (a1-1-2) exemplified as specific examples of the general formula (a1-1). ), Structural units represented by (a1-1-7) to (a1-1-15).
As the structural unit represented by the formula (a11-0-13), those in which R ⁸⁴ is an aliphatic polycyclic group formed together with the carbon atom to which R ⁸⁴ is bonded are preferably a 2-adamantyl group, The structural unit represented by the formula (a1-1-1) or (a1-1-2) is preferable. Further, R ⁸⁴ is also preferably the aliphatic polycyclic group which forms together with the carbon atom to which R ⁸⁴ is bonded is a "group obtained by removing one or more hydrogen atoms from tetracyclododecane", the formula (a1 The structural unit represented by (-1-8), (a1-1-9) or (a1-1-30) is also preferable.

In formula (a11-0-14), R and R ⁸² are the same as defined above. R ¹⁵ and ^{R 16} are the same as ^{R 15} and ^{R 16} in each of the general formulas (2-1) to (2-6).
Specific examples of the structural unit represented by the formula (a11-0-14) include the formulas (a1-1-35) and (a1-1-36) exemplified as specific examples of the general formula (a1-1). ).

In formula (a11-0-15), R and R ⁸⁴ are the same as defined above. R ¹⁵ and ^{R 16} are the same as ^{R 15} and ^{R 16} in each of the general formulas (2-1) to (2-6).
Specific examples of the structural unit represented by the formula (a11-0-15) include formulas (a1-1-4) to (a1-1-6) exemplified as specific examples of the general formula (a1-1). ) And (a1-1-34).

Examples of the structural unit represented by the formula (a11-0-2) include the structural unit represented by the formula (a1-3) or (a1-4), particularly represented by the formula (a1-3). Are preferred.
As the structural unit represented by the formula (a11-0-2), in particular, Y ^{2 in} the formula is —Y ²¹ —O—Y ²² — or —Y ²¹ —C (═O) —O—Y ^22. Those represented by-are preferred.
Preferred examples of the structural unit include a structural unit represented by the following general formula (a1-3-01); a structural unit represented by the following general formula (a1-3-02); 3-03) and the like.

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

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

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

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

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

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

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

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

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

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

When the component (A1) has the structural unit (a1), the structural unit (a1) may be one type or two or more types.
Among these, the structural unit (a1) is preferably a structural unit (a11) derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. .
When the structural unit (a1) is included in the component (A1), the proportion of the structural unit (a1) is preferably 15 to 70 mol% with respect to all the structural units constituting the component (A1), and is 15 to 60 mol. % Is more preferable, and 20 to 55 mol% is more preferable.
By setting the proportion of the structural unit (a1) to the lower limit value or more, a pattern can be easily obtained when a resist composition is formed, and the lithography properties such as sensitivity, resolution, and LWR are also improved. Moreover, it becomes easy to balance with another structural unit by setting it as an upper limit or less.

(Structural unit (a2))
In addition to the structural units (a0-1), (a0-2) and (a1), the component (A1) is an acrylic in which a hydrogen atom bonded to the α-position carbon atom may be further substituted with a substituent. A structural unit derived from an acid ester and containing a —SO ₂ -containing cyclic group (a2 ^S ), and an acryl in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent It may contain at least one structural unit (a2) selected from the group consisting of a structural unit (a2 ^L ) derived from an acid ester and comprising a lactone-containing cyclic group.
The structural unit (a2) contains a —SO ₂ -containing cyclic group or a lactone cyclic group so that the resist film formed using the resist composition containing the polymer of the present invention has adhesion to the substrate. And increase the affinity with a developer containing water (especially in the case of an alkali development process), thereby contributing to the improvement of lithography properties.

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

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

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

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

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

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

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

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

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

In formula (a2-0), R is the same as defined above.
R ²⁸ is the same as the —SO ₂ — containing cyclic group mentioned above.
R ²⁹ may be a single bond or a divalent linking group. Since it is excellent in the effect of this invention, it is preferable that it is a bivalent coupling group.
Examples of the divalent linking group for R ^29, not particularly limited, for example, those similar to the divalent linking group for X of the formula (I-1) in the like. Among these, those containing an alkylene group or an ester bond (—C (═O) —O—) are preferable.
The alkylene group is preferably a linear or branched alkylene group. Specifically, the same as the linear alkylene group and the branched alkylene group mentioned as the aliphatic hydrocarbon group for Y ² can be used.
As the divalent linking group containing an ester bond, in particular, the general formula: —R ³⁰ —C (═O) —O— [wherein R ³⁰ is a divalent linking group. ] Is preferable. That is, the structural unit (a2 ^S ) is preferably a structural unit represented by the following general formula (a2-0-1).

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

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

R ³⁰ is not particularly limited, and examples thereof include the same divalent linking groups as R ² in formula (a0-1).
The divalent linking group for R ³⁰ is preferably a linear or branched alkylene group, an aliphatic hydrocarbon group containing a ring in the structure, or a divalent linking group containing a hetero atom.
Examples of the linear or branched alkylene group, the aliphatic hydrocarbon group containing a ring in the structure, and the divalent linking group containing a hetero atom are the same as those for R ² in the formula (a0-1). Examples thereof include linear or branched alkylene groups, aliphatic hydrocarbon groups containing a ring in the structure, and divalent linking groups containing a hetero atom.
Among these, a linear or branched alkylene group or a divalent linking group containing an oxygen atom as a hetero atom is preferable.
As the linear alkylene group, a methylene group or an ethylene group is preferable, and a methylene group is particularly preferable.
As the branched alkylene group, an alkylmethylene group or an alkylethylene group is preferable, and —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — or —C (CH ₃ ) ₂ CH ₂ — is particularly preferable.
The divalent linking group containing an oxygen atom is preferably a divalent linking group containing an ether bond or an ester bond, and has the formula -AO-B-,-[A-C (= O) -O] _{m '.} A group represented by —B— or —A—O—C (═O) —B— is more preferable. A and B are each independently a divalent hydrocarbon group which may have a substituent, and are the same as A and B described above. m 'is an integer of 0-3.
Among them, preferred is a group represented by the formula -A-O-C (= O ) -B-, - represented by _{- (CH 2) c -O-} C (= O) - (CH 2) d The group is particularly preferred. c is an integer of 1 to 5, and 1 or 2 is preferable. d is an integer of 1-5, and 1 or 2 is preferable.

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

［式中、Ｒ、Ａ’、Ｒ^２７、ｚおよびＲ^３０はそれぞれ前記と同じである。］

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

In formula (a2-0-11), A ′ is preferably a methylene group, an oxygen atom (—O—) or a sulfur atom (—S—).
R ³⁰ is preferably a linear or branched alkylene group or a divalent linking group containing an oxygen atom. As the linear or branched alkylene group and the divalent linking group containing an oxygen atom in R ^30, the linear or branched alkylene group mentioned above and a divalent linking group containing an oxygen atom are mentioned. Examples are the same as the linking group.
As the structural unit represented by the formula (a2-0-12), a structural unit represented by the following general formula (a2-0-12a) or (a2-0-12b) is particularly preferable.

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

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

-Structural unit (a2 ^L ):
The structural unit (a2 ^L ) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and includes a lactone-containing cyclic group. is there.
Here, the lactone-containing cyclic group refers to a cyclic group containing a ring (lactone ring) containing —O—C (═O) — in the ring skeleton. The lactone ring is counted as the first ring. When only the lactone ring is present, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone cyclic group in the structural unit (a2 ^L ) is not particularly limited, and any one can be used. Specifically, as the lactone-containing monocyclic group, a group in which one hydrogen atom is removed from a 4- to 6-membered ring lactone, for example, a group in which one hydrogen atom is removed from β-propionolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed and a group in which one hydrogen atom has been removed from δ-valerolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
Examples of the structural unit (a2 ^L ) include those obtained by substituting R ²⁸ in the general formula (a2-0) with a lactone-containing cyclic group, and more specifically, the following general formula (a2- The structural unit represented by 1)-(a2-5) is mentioned.

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

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ′ is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a halogen atom. alkyl group, a hydroxyl group, an oxygen atom (= O), - COOR " , - OC (= O) R", a hydroxyalkyl group or a cyano group, R "represents a hydrogen atom or an alkyl ^{group; R 29} is a single A bond or a divalent linking group, s "is an integer of 0 to 2; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom. Yes; m is 0 or 1.]

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

As the structural unit (a2 ^L ), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formula (a2-1) to More preferably, at least one selected from the group consisting of structural units represented by (a2-3) is selected from the group consisting of structural units represented by the general formula (a2-1) or (a2-3) Particularly preferred is at least one of the above.
Among them, the formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-7), (a2-2-12), (a2-2-2-) 14), (a2-3-1), at least one selected from the group consisting of structural units represented by (a2-3-5) is preferred.

In the component (A1), as the structural unit (a2), one type of structural unit may be used, or two or more types may be used in combination. For example, as the structural unit (a2), only the structural unit (a2 ^S ) may be used, or only the structural unit (a2 ^L ) may be used, or they may be used in combination. As the structural unit (a2 ^S ) or the structural unit (a2 ^L ), one type may be used alone, or two or more types may be used in combination.

In the component (A1), the proportion of the structural unit (a2) is preferably 1 to 80 mol%, and preferably 10 to 70 mol%, based on the total of all structural units constituting the component (A1). More preferably, it is more preferably 10 to 65 mol%, particularly preferably 10 to 60 mol%.
By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units, such as various kinds of DOF, CDU, etc. The lithography characteristics and pattern shape of the film are improved.

In addition to the structural units (a0-1) and (a0-2), or the component (A1), in addition to the structural units (a0-1), (a0-2), and (a1), or In addition to the units (a0-1), (a0-2), (a1) and (a2), other than the structural units (a0-1), (a0-2), (a1) and (a2) The structural unit may be included.
The other structural unit is not particularly limited as long as it is another structural unit not classified into the above structural units (a0-1), (a0-2), (a1), and (a2). ArF excimer Many things conventionally known can be used as what is used for resin for resists, such as for lasers and for KrF excimer lasers (preferably for ArF excimer lasers).
Examples of the other structural unit include a structural unit (a4) derived from an (α-substituted) acrylate ester containing an acid non-dissociable aliphatic polycyclic group.

The “acid non-dissociable aliphatic polycyclic group” in the structural unit (a4) means that when an acid is generated from the structural unit (a0-2) or an arbitrary component (B) described later by exposure, It is an aliphatic polycyclic group which remains in the structural unit as it is without dissociating even when acting. By having the structural unit (a4) having such an aliphatic polycyclic group, the dry etching resistance of the formed resist pattern is improved. Moreover, the hydrophobicity of (A1) component increases. The improvement in hydrophobicity contributes to the improvement in resolution, resist pattern shape, etc., particularly in the case of organic solvent development.
Examples of the non-acid-dissociable aliphatic polycyclic group include substitution with a carbon atom bonded to an atom adjacent to the aliphatic polycyclic group (for example, —O— in —C (═O) —O—). And monovalent aliphatic polycyclic groups to which groups (atoms or groups other than hydrogen atoms) are not bonded.
The aliphatic cyclic group is not particularly limited as long as it is non-acid dissociable, and is used for a resin component of a resist composition such as for ArF excimer laser and for KrF excimer laser (preferably for ArF excimer laser). A number of conventionally known devices can be used. The aliphatic cyclic group may be saturated, unsaturated, or saturated. Specific examples include groups in which one hydrogen atom has been removed from a cycloalkane such as monocycloalkane and polycycloalkane mentioned in the description of the aliphatic cyclic group in the structural unit (a1).
The aliphatic cyclic group may be monocyclic or polycyclic, and is preferably polycyclic because the above effects are excellent. In particular, those having 2 to 4 rings are preferable, and among them, 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. .
Specific examples of the non-acid-dissociable aliphatic cyclic group include, for example, a carbon atom bonded to an atom adjacent to the aliphatic cyclic group (for example, —O— in —C (═O) —O—). And monovalent aliphatic cyclic groups to which substituents (atoms or groups other than hydrogen atoms) are not bonded. Specifically, a group in which R ¹⁴ in the groups represented by formulas (1-1) to (1-9) described in the description of the structural unit (a1) is substituted with a hydrogen atom; carbon constituting the ring skeleton And a group obtained by removing a hydrogen atom from the tertiary carbon atom of a cycloalkane having a tertiary carbon atom formed only by atoms.
A substituent may be bonded to the aliphatic cyclic group. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group, a hydroxyl group and a cyano group.
As the structural unit (a4), structural units represented by general formula (a4-0) shown below are preferred, and structural units represented by general formulas (a4-1) to (a4-8) shown below are particularly preferred.

［式中、Ｒは前記と同じであり、Ｒ^４０は酸非解離性の脂肪族多環式基である。］

[Wherein, R is the same as defined above, and R ⁴⁰ represents a non-acid-dissociable aliphatic polycyclic group. ]

［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の整数であり、ｑ、ｒ”、ｖ”、ｗ”はそれぞれ独立に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] S is an integer of 1 to 3, and q, r ″, v ″, and w ″ are each independently an integer of 1 to 3.]

In formula (a4-6), j is preferably 1 or 2, and more preferably 1. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group.
In formula (a4-7), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a4-8), 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.

The structural unit (a4) contained in the component (A1) may be one type or two or more types.
In the component (A1), the proportion of the structural unit (a4) is preferably 1 to 30 mol%, more preferably 1 to 20 mol%, based on the total of all the structural units constituting the component (A1). 20 mol% is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a4) can be sufficiently obtained, and by setting the upper limit value or less, it is possible to balance with other structural units.

The component (A1) is a copolymer having the structural units (a0-1) and (a0-2), and preferably has a structural unit (a1) and / or a structural unit (a2).
As the component (A1), those composed of the structural units (a0-1) and (a0-2); those composed of the structural units (a0-1), (a0-2) and (a1); a0-1), (a0-2), (a1) and (a2 ^S ); structural units (a0-1), (a0-2), (a1) and (a2 ^L ) It can illustrate as a suitable thing.
More specifically, the structural unit represented by the formula (a0-10) and the formula (a0-2-11), (a0-2-12), or (a0-2-21) A structural unit, a structural unit represented by the formula (a1-1) or (a1-2), and a structural unit represented by the formula (a2-0-12), (a2-1) or (a2-2). Those having a structural unit are preferred; the structural unit represented by the formula (a0-1-5), (a0-1-9), (a0-1-11) or (a0-1-17); A structural unit represented by the formula (a0-2-11), (a0-2-12) or (a0-2-21); and the formula (a1-1-23) or (a1-1-26). , (A1-1-31), (a1-1-34) or (a1-2-6), and the formula (a2-0-12a), (a2-1-1), ( 2-1-10), (a2-2-12), or (more preferably has a structural unit represented by a2-2-18).

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, and 2000 to 2000 20000 is most preferred. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
The dispersity (Mw / Mn) is not particularly limited, but is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5. In addition, Mn shows a number average molecular weight.

The component (A1) can be obtained by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN).
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
A commercially available monomer may be used as the monomer for deriving each structural unit, or the monomer may be synthesized using a known method. For example, the monomer for deriving the structural unit (a3) can be produced by the method disclosed in JP2009-286720A. Moreover, among the structural unit (a0), a monomer that induces a structural unit having a cation moiety on the resin side, such as the structural unit represented by the general formula (a0-1), is (α-substituted) acrylic acid. It can be easily synthesized by an esterification reaction between chloride and an onium salt having a hydroxyl group in the cation part. Moreover, among the structural unit (a0), a monomer that induces a structural unit having an anion moiety on the resin side, such as the structural unit represented by the general formula (a0-2), is disclosed in JP-A-2009-91350. It can be produced by the methods disclosed in Japanese Patent Laid-Open No. 2010-095643, Japanese Patent Laid-Open No. 2009-7327, and the like.

<Optional component>
[Component (B)]
The resist composition of the present invention may further contain an acid generator component (B) that generates an acid upon exposure.
When the resist composition of the present invention contains the component (B), the component (B) is not particularly limited, and it is possible to use what has been proposed as an acid generator for chemically amplified resists. it can. 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 poly (bissulfonyl) diazomethanes. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく；Ｒ^４”は、置換基を有していてもよいアルキル基、ハロゲン化アルキル基、アリール基、またはアルケニル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group; among R ¹ ″ to R ³ ″ in formula (b-1), Any two may be bonded to each other to form a ring together with the sulfur atom in the formula; R ⁴ ″ may be an optionally substituted alkyl group, halogenated alkyl group, aryl group, or alkenyl group; And at least one of R ¹ ″ to R ³ ″ represents an aryl group, and at least one of R ⁵ ″ to R ⁶ ″ represents an aryl group.]

R ¹ ″ to R ³ ″ in Formula (b-1) and R ⁵ ″ to R ⁶ ″ in Formula (b-2) are respectively R ¹ ″ to R ^{3 in} Formula (c-1). ", The same as R ⁵ " to R ⁶ "in the formula (c-2).
Formula (b-1) ~ (b -2) in ^R 4 "SO ₃ ^- is described in the structural unit _{^{(a0-2) R 4" SO 3}} - is the same as.
Moreover, as an onium salt type | system | group acid generator, in the said general formula (b-1) or (b-2), an anion part is represented by the said general formula (b-3) or (b-4). An onium salt-based acid generator replaced with can also be used (the cation moiety is the same as (b-1) or (b-2)).

Moreover, the sulfonium salt which has a cation part represented by the said Formula (c-3) can also be used as an onium salt type | system | group acid generator. The anion part of the sulfonium salt having a cation part represented by the formula (c-3) is not particularly limited, and may be the same as the anion part of the onium salt acid generators proposed so far. Examples of the anion moiety include fluorinated alkyl sulfonate ions such as the anion moiety (R ⁴ ″ SO ₃ ⁻ ) of the onium salt acid generator represented by the general formula (b-1) or (b-2). An anion represented by the general formula (b-3) or (b-4).

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation (exposure) of radiation. It is what you have. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

（式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

(In formula (B-1), R ³¹ and R ³² each independently represents an organic group.)

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ^31, a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with 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. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.
As the organic group for R ^32, a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ”は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3.]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.
As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.
The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), pamphlet of International Publication No. 04/074242, An oxime sulfonate-based acid generator disclosed in Examples 1 to 40) on pages 65 to 85 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can also be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

As the component (B), one type of acid generator described above may be used alone, or two or more types may be used in combination.
The content of the component (B) in the resist composition of the present invention is preferably 0 to 40 parts by mass and more preferably 0 to 30 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (C) described later. Preferably, 0 to 20 parts by mass is more preferable. When it is 40 parts by mass or less, a uniform solution is obtained when each component of the resist composition is dissolved in an organic solvent, and the storage stability is improved, which is preferable.

<Other optional components>
The resist composition of the present invention contains a base material component (hereinafter referred to as “component (C)”) that does not fall under the component (A) and increases in polarity by the action of an acid, as long as the effects of the present invention are not impaired. May be.
The “base component” means an organic compound having a film forming ability as described above.
The component (C) is not particularly limited, and can be appropriately selected from those conventionally used as the base component of the chemically amplified resist composition. As the component (C), a resin may be used, a low molecular compound may be used, or these may be used in combination. As the component (C), one type may be used alone, or two or more types may be used in combination.
Examples of the resin used as the component (C) include a chemically amplified resist composition used for forming a positive resist pattern in an alkali development process or a negative resist pattern in a solvent development process. Any number of conventionally known base components for the chemically amplified resist composition used (for example, base resins for ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser), etc.) Select and use. For example, as a resin used as a base component for an ArF excimer laser, a resin having the structural unit (a1) as an essential structural unit and optionally further including the structural units (a2), (a4), etc. Is mentioned.

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

The resist composition of the present invention is a group consisting of 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, retention stability over time, etc. May contain at least one compound (E) selected from (hereinafter referred to as component (E)).
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids and derivatives thereof include phosphoric acid, phosphonic acid, phosphinic acid and the like, and 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 the phosphinic acid derivatives include phosphinic acid esters such as 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.

  The resist composition of the present invention may further contain, if desired, miscible additives such as an additional resin for improving the performance of the resist film, a surfactant for improving coatability, a dissolution inhibitor, Plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like can be added and contained as appropriate.

The resist composition of the present invention 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, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone;
Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol;
Compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl ether, monopropyl of the polyhydric alcohols or the compound having an ester bond Derivatives of polyhydric alcohols such as ethers, monoalkyl ethers such as monobutyl ether or compounds having an ether bond such as monophenyl ether [in these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) Is preferred];
Cyclic ethers such as dioxane and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate;
Aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. be able to.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), 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. For example, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3. Further, when PGME and cyclohexanone are blended as polar solvents, the mass ratio of PGMEA: (PGME + cyclohexanone) is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, and even more preferably 3. : 7 to 7: 3.
In addition, as the component (S), PGMEA, EL or a mixed solvent of PGMEA and a polar solvent and a mixed solvent of γ-butyrolactone are also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 99: 1.
The amount of component (S) used is not particularly limited, but is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 1 -20% by mass, preferably 2-15% by mass.

The resist composition of the present invention is excellent in lithography properties such as sensitivity, roughness, resolution, and pattern shape. The reason why such an effect is obtained is not clear, but is presumed as follows.
The resist composition of the present invention contains the structural unit (a0-2) that is uniformly distributed in the resist film when the component (A1) contains the structural unit (a0-2) that generates an acid upon exposure. Acid is uniformly generated in the exposed area. As a result, the acid-decomposable group in the (A1) component of the exposed portion is easily decomposed uniformly, so that the lithography properties such as resolution are improved as compared with a resist composition using a conventional acid generator. I think that.
In addition, when the structural unit (a1) that is decomposed by an acid is contained in the component (A1), the structural unit (a0-2) that generates an acid upon exposure and the component (A1) are present relatively close to each other. Thus, it is presumed that the above-described effect becomes particularly remarkable because the acid-decomposable group is easily decomposed by an acid.

In addition, since the structural unit (a0-1) contained in the component (A1) of the present invention has a sulfonamide group at the terminal, it can function as a proton source. By supplying protons from the structural unit (a0-1), it is considered that the acid generation efficiency of the structural unit (a0-2) is improved and the sensitivity is improved. In addition, by improving the sensitivity, the degree of freedom regarding the baking temperature and the use of the component (D) described above is increased, the resist composition and the pattern forming method can be further optimized, and the lithography characteristics and pattern shape are improved. It becomes possible to make it.
Conventionally, a proton source having a hydroxyl group typified by phenol is generally known. However, since phenol can cause a side reaction, a lithography composition can be obtained by adding a certain amount or more to the resist composition. And the pattern shape may be deteriorated. On the other hand, the structural unit (a0-1) of the present invention can function as a proton source like phenol and does not cause a side reaction, and the above effect is considered to be obtained satisfactorily.

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

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

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

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

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

As the organic solvent contained in the rinsing liquid used for the rinsing treatment after the development process in the solvent development process, for example, among the organic solvents mentioned as the organic solvent contained in the organic developer, those which are difficult to dissolve the resist pattern are appropriately used. You can select and use. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, and at least one selected from alcohol solvents and ester solvents is preferable. More preferred are alcohol solvents.
The 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.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
In this example, a compound represented by (1) in the chemical formula is described as “compound (1)”, and the compounds represented by other formulas are also described in the same manner.
In the analysis by NMR, the internal standard of ¹ H-NMR and the internal standard of ¹³ C-NMR is tetramethylsilane (TMS). The internal standard of ¹⁹ F-NMR is hexafluorobenzene (however, the peak of hexafluorobenzene was set to −160 ppm).

[Polymer Synthesis Examples 1 to 30: Synthesis of Polymer Compounds 1 to 30]
The high molecular compounds 1-30 were synthesize | combined by the conventional method using the following monomers (1)-(30) which derive | lead-in the structural unit which comprises each high molecular compound. The polymer compounds having the monomers (12), (15), (16), (20), (21), and (22) are monomers (12), (15), (16), (20), In (21) and (22), the polymer was once polymerized using a monomer whose counter cation is triphenylsulfonium, and then salt exchanged with the target counter cation by a conventional method.
The obtained polymer compound, as a result of an analysis by carbon 13 nuclear magnetic resonance spectrum (600 MHz - ¹³ C-NMR) (ratio of the respective structural units within the structural formula (molar ratio)) was measured by GPC The weight average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) in terms of standard polystyrene are shown in Tables 1 to 3, respectively.

[Examples 1 to 22, Comparative Examples 1 to 8]
Each component shown in Tables 4 to 5 was mixed and dissolved to prepare a positive resist composition.

Each abbreviation in Tables 4 to 5 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1 to (A) -30: the polymer compounds 1 to 30
(B) -1: The following compound (B) -1.
(C) -1: Polymer compound [Mw = 7000, Mw / Mn = 1.88, derived from monomer 2] obtained in the same manner as in Polymer Synthesis Example 1 using monomer 2 and monomer 3 Structural unit / Structural unit derived from monomer 3 = 50/50 (molar ratio)].
(D) -1: tri-n-octylamine.
(E) -1: salicylic acid.
(S) -1: Mixed solvent of PGMEA / PGME / cyclohexanone = 30/20/50 (mass ratio).
(S) -2: γ-butyrolactone.

<Formation of resist pattern> [Sensitivity]
By applying the resist composition of each example on an 8-inch silicon wafer using a spinner, performing a pre-bake (PAB) treatment at 140 ° C. for 60 seconds on a hot plate, and drying, A resist film having a thickness of 50 nm was formed.
Next, the resist film was exposed at an acceleration voltage of 50 keV using an electron beam lithography machine HL-800D (VSB) (manufactured by Hitachi), and subjected to PEB treatment for 60 seconds at the temperatures shown in Tables 6-7. Further, it was alkali-developed with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 60 seconds at 23 ° C., and water was used for 15 seconds using pure water. Rinse and shake-dry.
As a result, in all examples, a 1: 1 LS pattern having a line width of 100 nm and a pitch of 200 nm was formed on the resist film. The optimum exposure dose Eop (μC / cm ² ; sensitivity) at which the LS pattern is formed was determined. The results are listed in Tables 6-7.

[Line edge roughness (LER)]
The pattern roughness of the 1: 1 LS pattern line formed at the optimum exposure amount Eop was evaluated.
More specifically, 40 line edge widths (variations from straight lines) were measured with a length measurement SEM (scanning electron microscope, acceleration voltage 300 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation), and the result 3 times the standard deviation (s) (3 s) was calculated as a scale indicating LER.
3s obtained in this way means that the smaller the value is, the smaller the roughness is and an LS pattern having a uniform width is obtained. The results are shown in Tables 6-7.

[Resolution]
The limiting resolution (nm) in the Eop was determined using a scanning electron microscope S-9380 (manufactured by Hitachi High-Technology Corporation). The results are shown in Tables 6-7.

[Pattern shape evaluation]
The cross-sectional shape of the 1: 1 LS pattern formed at the optimum exposure dose Eop was observed using a scanning electron microscope (trade name: SU-8000, manufactured by Hitachi High-Technologies Corporation), and the shape was evaluated according to the following criteria. did. The results are shown in Tables 6-7.
○: The rectangularity is high and good.
X: Soo-drawn shape and rectangularity is low.

From the above results, the resist composition of Example 1 having the structural unit (a0-1) and the structural unit (a0-2) is the resist composition of Comparative Example 1 having no structural unit (a0-1), Compared to the resist composition of Comparative Examples 2 to 6 having a structural unit containing a hydroxyl group instead of the structural unit (a0-1) and the resist composition of Comparative Example 7 having no structural unit (a0-2), The sensitivity was equal to or higher, and the roughness, resolution, and pattern shape were excellent.
Moreover, the resist composition of Example 2 having the structural unit (a0-1) and the structural unit (a0-2) is Comparative Example 8 having a structural unit containing a hydroxyl group instead of the structural unit (a0-1). Compared with the resist composition, the sensitivity, roughness, resolution and pattern shape were excellent.
Further, the resist compositions of Examples 3 to 22 in which structural units (a0-1), (a0-2), (a1), and (a2) are partially changed are the same as the resist compositions of Examples 1 and 2. In addition, it was confirmed that the film had good sensitivity, roughness, resolution and pattern shape.

Claims (5)

A resist composition containing a base material component (A) that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid,
The substrate component (A) is a resin component (A1) having a structural unit (a0-1) represented by the following general formula (a0-1) and a structural unit (a0-2) that generates an acid upon exposure. A resist composition comprising:

[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 R ² is a divalent linking group. ] The resist composition according to claim 1, wherein the structural unit (a0-2) has a group represented by the following general formula (a0-21) or (a0-22).

[Wherein, Q ¹ and Q ² are each independently a single bond or a divalent linking group, R ³ , R ⁴ and R ⁵ are each independently an organic group, and R ⁴ and R ⁵ are mutually bonded. Thus, a ring may be formed together with the sulfur atom in the formula, and V ⁻ is a counter anion. A ⁻ is an organic group containing an anion, M ^{m +} is an organic cation, and m is an integer of 1 to 3. ] The resist composition according to claim 2, wherein the structural unit (a0-2) is a structural unit represented by the following general formula (a0-21-1) or (a0-22-1).

[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 Q ¹ and Q ² are each independently a single bond or a divalent linking group. , R ^{3 to} R ⁵ are each independently an organic group, R ⁴ and R ⁵ may be bonded to each other to form a ring together with the sulfur atom in the formula, and V ⁻ is a counter anion. A ⁻ is an organic group containing an anion, M ^{m +} is an organic cation, and m is an integer of 1 to 3. ]   The resist composition according to any one of claims 1 to 3, wherein the resin component (A1) further comprises a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid. .   A step of forming a resist film on the support using the resist composition according to any one of claims 1 to 4, a step of exposing the resist film, and developing the resist film to form a resist pattern A resist pattern forming method including a forming step.