JP5903224B2 - Compound, radical polymerization initiator, compound production method, polymer, resist composition, resist pattern formation method. - Google Patents

Description

  The present invention relates to a novel compound useful as a radical polymerization initiator, a radical polymerization initiator comprising the compound, a method for producing the compound, a novel polymer useful as a resist composition, a resist composition containing the polymer, And a resist pattern forming method using the resist composition.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film.
A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the exposure light source is generally shortened in wavelength (increased energy). Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. Further, studies have been made on electron beams having shorter wavelengths (higher energy) than these excimer lasers, EUV (extreme ultraviolet rays), X-rays, and the like.

Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions.
As a resist material satisfying such requirements, a chemically amplified resist composition containing a base material component whose solubility in a developing solution is changed by the action of an acid and an acid generator component that generates an acid upon exposure is used. ing.
For example, when the developer is an alkali developer (alkaline development process), the positive chemically amplified resist composition includes a resin component (base resin) whose solubility in an alkali developer is increased by the action of an acid, an acid Those containing a generator component are generally used. When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the acid generator component in the exposed portion, and the alkali developer of the resin component is generated by the action of the acid. As a result, the exposed area becomes soluble in an alkaline developer. Then, a positive pattern in which an unexposed portion remains as a pattern is formed. Here, as the base resin, a resin whose polarity is increased by the action of an acid is used, and the solubility in an alkali developer is increased while the solubility in an organic solvent is decreased. Therefore, when a process using a developer containing an organic solvent (organic developer) (hereinafter sometimes referred to as a solvent development process or a negative development process) is applied instead of an alkali development process, Therefore, in the solvent development process, the unexposed portion of the resist film is dissolved and removed by the organic developer, and the exposed portion remains as a pattern in the solvent development process. Is formed. For example, Patent Document 1 proposes a negative development process.

  Currently, as a base resin of a resist composition used in ArF excimer laser lithography and the like, a resin (acrylic resin) having a structural unit derived from a (meth) acrylate ester in its main chain because of its excellent transparency near 193 nm. And the like are generally used (see, for example, Patent Document 2).

The polymer used for the base resin is usually produced by radical polymerization of monomers having various functions. As the polymerization initiator in radical polymerization, azo polymerization initiators such as azobisisobutyronitrile (AIBN) and dimethyl 2,2′-azobis (2-methylpropionate) are generally used.
The azo polymerization initiator is decomposed by heat or light to generate nitrogen gas and radicals, and the radicals are addition-polymerized with monomers to synthesize a polymer. Therefore, a partial structure of an azo polymerization initiator is introduced at the end of the synthesized polymer.
In recent years, paying attention to the partial structure of a polymerization initiator introduced into the polymer terminal, a polymerization initiator using a base-dissociable group that is a functional group as the partial structure, and a weight obtained by using the polymerization initiator. Coalescence is disclosed (see Patent Document 3).

JP 2008-292975 A JP 2003-241385 A JP 2010-37528 A

In the future, there is a demand for new materials that can be used for lithography applications as further advancement of lithography technology and expansion of application fields are expected. For example, as the pattern becomes finer, the resist material has not only sensitivity and resolution, but also roughness (in the case of a line pattern, LWR (line width roughness: line width non-uniformity)) and other hole patterns. Therefore, improvement in various lithography characteristics such as roundness, MEF, EL margin, and pattern shape is required. However, even when the base resins described in Patent Documents 2 to 3 are used, there is still room for improvement with respect to lithography characteristics and pattern shapes.
The present invention has been made in view of the above circumstances, and is a resist composition excellent in lithography characteristics and pattern shape, a novel polymer useful for the resist composition, and initiation of radical polymerization used in the production of the polymer It is an object of the present invention to provide a novel compound useful as an agent, a method for producing the compound, a radical polymerization initiator comprising the compound, and a resist pattern forming method using the resist composition.

In order to solve the above problems, the present invention employs the following configuration.
That is, the first aspect of the present invention is a compound represented by the following general formula (I).

［式中、Ｒ^１は炭素数１〜１０の炭化水素基であり、Ｚはシアノ基である。Ｘは２価の連結基であって、−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−、及び−ＮＨ−Ｃ（＝ＮＨ）−のいずれかを、少なくとも式中のＱと接する末端に有する。ｐは１〜３の整数である。Ｑは（ｐ＋１）価の炭化水素基であり、ｐが１の場合のみ、Ｑは単結合であってもよい。Ｒ^２は単結合、置換基を有していてもよいアルキレン基、又は置換基を有していてもよい芳香族基であり、ｑ、ｒはそれぞれ独立に０又は１であり、Ａ^＋は金属カチオン又は有機カチオンである。式中の複数のＲ^１、Ｚ、Ｘ、ｐ、Ｑ、Ｒ^２、ｑ、ｒ、Ａ^＋はそれぞれ同じであっても異なっていてもよい。］

[Wherein, R ¹ is a hydrocarbon group having 1 to 10 carbon atoms, and Z is a cyano group . X is a divalent linking group, and at least one of —O—C (═O) —, —NH—C (═O) —, and —NH—C (═NH) — It is at the end that contacts Q. p is an integer of 1 to 3. Q is a (p + 1) -valent hydrocarbon group, and Q may be a single bond only when p is 1. R ² is a single bond, an alkylene group which may have a substituent, or an aromatic group which may have a substituent, q and r are each independently 0 or 1, and A ⁺ is It is a metal cation or an organic cation. A plurality of R ¹ , Z, X, p, Q, R ² , q, r, and A ⁺ in the formula may be the same or different. ]

The second aspect of the present invention is a radical polymerization initiator comprising the compound of the first aspect.
3rd aspect of this invention is a manufacturing method of the compound of said 1st aspect, Comprising: The compound represented with the following general formula (i-1), and represented with the following general formula (i-2) It is a manufacturing method including the process with which a compound is made to react.

［式中、Ｒ^１、Ｚ、Ｘ、Ｑ、ｐ、ｑ、Ｒ^２、ｒ、Ａ^＋はそれぞれ前記同様であり、Ｂ^１、Ｂ^２はそれぞれ独立にＨ又はＯＨである。式中の複数のＲ^１、Ｚ、Ｘ、ｐ、Ｑ、Ｂ^１はそれぞれ同じであっても異なっていてもよい。］

[Wherein, R ¹ , Z, X, Q, p, q, R ² , r, and A ⁺ are the same as defined above, and B ¹ and B ² are each independently H or OH. A plurality of R ¹ , Z, X, p, Q, and B ¹ in the formula may be the same or different. ]

  The fourth aspect of the present invention is a polymer having a group represented by the following general formula (I-1) at at least one end of the main chain.

［式中、Ｒ^１は炭素数１〜１０の炭化水素基であり、Ｚはシアノ基である。Ｘは２価の連結基であって、−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−、及び−ＮＨ−Ｃ（＝ＮＨ）−のいずれかを、少なくとも式中のＱと接する末端に有する。ｐは１〜３の整数である。Ｑは（ｐ＋１）価の炭化水素基であり、ｐが１の場合のみ、Ｑは単結合であってもよい。Ｒ^２は単結合、置換基を有していてもよいアルキレン基、又は置換基を有していてもよい芳香族基であり、ｑ、ｒはそれぞれ独立に０又は１であり、Ｍ^＋は有機カチオンである。］

[Wherein, R ¹ is a hydrocarbon group having 1 to 10 carbon atoms, and Z is a cyano group . X is a divalent linking group, and at least one of —O—C (═O) —, —NH—C (═O) —, and —NH—C (═NH) — It is at the end that contacts Q. p is an integer of 1 to 3. Q is a (p + 1) -valent hydrocarbon group, and Q may be a single bond only when p is 1. R ² is a single bond, an optionally substituted alkylene group, or an optionally substituted aromatic group, q and r are each independently 0 or 1, and M ⁺ is Organic cation. ]

A fifth aspect of the present invention is a resist composition containing the polymer of the fourth aspect.
According to a sixth aspect of the present invention, there is provided a step of forming a resist film on a support using the resist composition of the fifth aspect, a step of exposing the resist film, and developing the resist film 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.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.
The “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Fluorinated alkyl group” or “fluorinated alkylene group” refers to a group in which part or all of the hydrogen atoms of an alkyl group or alkylene group are substituted with fluorine atoms.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“Acrylic acid ester” is a compound in which the hydrogen atom at the carboxy group terminal of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
The substituent in the “acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent” includes a halogen atom, an alkyl group having 1 to 5 carbon atoms, and a halogen atom having 1 to 5 carbon atoms. Alkyl group, hydroxyalkyl group and the like. Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
Examples of the halogen atom in the substituent which may be bonded to the α-position carbon atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Specific examples of the alkyl group having 1 to 5 carbon atoms in the substituent which may be bonded to the α-position carbon atom include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, Examples thereof include linear or branched alkyl groups such as tert-butyl group, pentyl group, isopentyl group, and neopentyl group.
Further, as the halogenated alkyl group having 1 to 5 carbon atoms in the substituent, a part or all of the hydrogen atoms in the above-mentioned “alkyl group having 1 to 5 carbon atoms in the substituent” are halogen atoms. And a 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.
Specific examples of the hydroxyalkyl group in the substituent include groups in which part or all of the hydrogen atoms in the above-mentioned “alkyl group having 1 to 5 carbon atoms in the substituent” are substituted with a hydroxy group. .
In the present invention, it is preferable that a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms is bonded to the α-position carbon atom. It is more preferably a C 1-5 alkyl group or a C 1-5 fluorinated alkyl group, and most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.
“Exposure” is a concept including general irradiation of radiation.

  According to the present invention, a resist composition excellent in lithography characteristics and pattern shape, a novel polymer useful for the resist composition, a novel compound useful as a radical polymerization initiator used in the production of the polymer, A production method, a radical polymerization initiator comprising the compound, and a resist pattern forming method using the resist composition can be provided.

≪Compound≫
The compound of the first aspect of the present invention is a compound represented by the following general formula (I) (hereinafter sometimes referred to as “compound (I)”).

［式中、Ｒ^１は炭素数１〜１０の炭化水素基であり、Ｚは炭素数１〜１０の炭化水素基又はシアノ基であり、Ｒ^１とＺとは相互に結合して環を形成していてもよい。Ｘは２価の連結基であって、−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−、及び−ＮＨ−Ｃ（＝ＮＨ）−のいずれかを、少なくとも式中のＱと接する末端に有する。ｐは１〜３の整数である。Ｑは（ｐ＋１）価の炭化水素基であり、ｐが１の場合のみ、Ｑは単結合であってもよい。Ｒ^２は単結合、置換基を有していてもよいアルキレン基、又は置換基を有していてもよい芳香族基であり、ｑ、ｒはそれぞれ独立に０又は１であり、Ａ^＋は金属カチオン又は有機カチオンである。式中の複数のＲ^１、Ｚ、Ｘ、ｐ、Ｑ、Ｒ^２、ｑ、ｒ、Ａ^＋はそれぞれ同じであっても異なっていてもよい。］

[Wherein, R ¹ is a hydrocarbon group having 1 to 10 carbon atoms, Z is a hydrocarbon group having 1 to 10 carbon atoms or a cyano group, and R ¹ and Z are bonded to each other to form a ring. You may do it. X is a divalent linking group, and at least one of —O—C (═O) —, —NH—C (═O) —, and —NH—C (═NH) — It is at the end that contacts Q. p is an integer of 1 to 3. Q is a (p + 1) -valent hydrocarbon group, and Q may be a single bond only when p is 1. R ² is a single bond, an alkylene group which may have a substituent, or an aromatic group which may have a substituent, q and r are each independently 0 or 1, and A ⁺ is It is a metal cation or an organic cation. A plurality of R ¹ , Z, X, p, Q, R ² , q, r, and A ⁺ in the formula may be the same or different. ]

In formula (I), R ¹ is a hydrocarbon group having 1 to 10 carbon atoms. The hydrocarbon group having 1 to 10 carbon atoms may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, preferably an aliphatic hydrocarbon group, and a monovalent aliphatic group. More preferably, it is a group saturated hydrocarbon group (alkyl group).
More specifically, examples of the alkyl group include a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in the structure.
The linear alkyl group preferably has 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, and most preferably 1 to 2 carbon atoms. 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 particularly preferable.
The branched alkyl group preferably has 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, and the like, and an isopropyl group or a tert-butyl group is most preferable.
Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group is the chain described above. And a group that is bonded to the terminal of the chain-like aliphatic hydrocarbon group or intervenes in the middle of the chain-like aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 8 carbon atoms, and more preferably 4 to 6 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

In formula (I), Z is a C1-C10 hydrocarbon group or a cyano group (-CN).
Examples of the hydrocarbon group having 1 to 10 carbon atoms Z, the same as the hydrocarbon group having 1 to 10 carbon atoms of the R ¹ can be mentioned.

In the present invention, R ¹ and Z are each independently a linear or branched alkyl group, and the end of R ^{1 and} the end of Z may be bonded to each other to form a ring. Good. As the ring to be formed, a ring having 3 to 8 carbon atoms is preferable, and cyclopentane, cyclohexane, cycloheptane or cyclooctane is preferable.
Among them, R ¹ and Z in the present invention include a combination of a methyl group and a methyl group; a combination of an ethyl group and an ethyl group; a combination of a methyl group and a cyano group; a combination of an ethyl group and a cyano group; A group in which two carbon atoms are removed from cyclopentane formed by bonding to is preferable, R ¹ is a methyl group, and Z is particularly preferably a cyano group.
In addition, although several R < ¹ >, Z in Formula (I) may be same or different, it is preferable industrially the same.

In Formula (I), X is a divalent linking group, and is any one of —O—C (═O) —, —NH—C (═O) —, and —NH—C (═NH) —. At least at the end in contact with Q in the formula. The terminal in contact with Q in the formula is in contact with — (C (═O) —O) _q —, R ² , —CF ₂ — or SO ₃ ^— in formula (I) when Q is a single bond. It means the end. Even if the bivalent coupling group of X consists only of -O-C (= O)-, -NH-C (= O)-, and -NH-C (= NH)-. Good. X may have —O—C (═O) —, —NH—C (═O) —, or —NH—C (═NH) — in addition to the terminal in contact with Q in the formula. Good.
The divalent linking group of X includes only —O—C (═O) —, —NH—C (═O) —, or —NH—C (═NH) —; An optionally divalent hydrocarbon group, or a divalent linking group containing a hetero atom, and -O-C (= O)-, -NH-C (= O)-, or -NH-C ( ═NH) — and the like.

(Divalent hydrocarbon group which may have a substituent)
In the present invention, the hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.
The divalent hydrocarbon group which may have a substituent may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.
The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

Specific examples of the aliphatic hydrocarbon group in the divalent hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like. It is done.
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 chain-like aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

Examples of the aliphatic hydrocarbon group including a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group includes the chain described above. And a group that is bonded to the terminal of the chain-like aliphatic hydrocarbon group or intervenes in the middle of the chain-like aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

Examples of the aromatic hydrocarbon group in the divalent hydrocarbon group include monovalent groups such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. A divalent aromatic hydrocarbon group obtained by removing one hydrogen atom from the nucleus of the aromatic hydrocarbon of the aromatic hydrocarbon group; a part of carbon atoms constituting the ring of the divalent aromatic hydrocarbon group Is an aromatic hydrocarbon group substituted with a hetero atom such as an oxygen atom, a sulfur atom or a nitrogen atom; benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthyl An arylalkyl group such as an ethyl group, and an aromatic hydrocarbon group obtained by further removing one hydrogen atom from the nucleus of the aromatic hydrocarbon.
The aromatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

(Divalent linking group containing hetero atom)
Examples of the divalent linking group containing a hetero atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C ( ═O) —NH—, —NH—, —NH—C (═NH) — (H may be substituted with a substituent such as an alkyl group or an acyl group), —S—, —S (= O) ₂ —, —S (═O) ₂ —O—, “—A—O (oxygen atom) —B— (wherein A and B may each independently have a substituent) Or a combination of a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom. Examples of the divalent hydrocarbon group which may have a substituent include those similar to the hydrocarbon group which may have a substituent described above, and may be linear, branched, or structural An aliphatic hydrocarbon group containing a ring therein is preferred.

In the case of -NH-, the substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 5 carbon atoms. It is particularly preferred.
In the case of “A-O-B”, A and B are each independently a divalent hydrocarbon group which may have a substituent.

The hydrocarbon group in A 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 for A may be saturated or unsaturated, and is usually preferably saturated.
Specific examples of the aliphatic hydrocarbon group for A include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure. These are the same as above.
Among these, as A, a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 2 to 5 carbon atoms is further preferable, and an ethylene group is most preferable.

Examples of the hydrocarbon group for B include the same divalent hydrocarbon groups as those described above for A.
B is preferably a linear or branched aliphatic hydrocarbon group, particularly preferably a methylene group or an alkylmethylene group.
The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

When X in the present invention is composed only of any of —O—C (═O) —, —NH—C (═O) —, and —NH—C (═NH) —, X is —O— C (═O) — or —NH—C (═O) — is preferable. At this time, the carbon atom (C) in —O—C (═O) — or the carbon atom (C) in —NH—C (═O) — is directly bonded to the carbon atom bonded to R ¹ and Z. Bonding is preferred.
In addition, X is a combination of the above-described divalent group and any one of —O—C (═O) —, —NH—C (═O) —, and —NH—C (═NH) —. In some cases, X is a linear or branched aliphatic hydrocarbon group having 1 to 5 carbon atoms, or a divalent linking group containing a hetero atom, -O-C (= O)-, -NH. A combination with any one of —C (═O) — and —NH—C (═NH) — is preferable; 1 selected from a divalent linking group containing a methylene group, an ethylene group, and —NH—. More preferably, it is a combination of one or more linking groups and any one of —O—C (═O) —, —NH—C (═O) —, and —NH—C (═NH) —; Particularly preferred is a combination of two or more groups selected from the group, —O—C (═O) —, and —NH—C (═O) —. Arbitrariness.
In addition, although several X in Formula (I) may be the same or different, it is preferable industrially the same.

In formula (I), p is an integer of 1-3. By setting p to 2 or 3, the ratio of SO ₃ ⁻ per compound can be increased. Therefore, the ratio of the sulfonic acid moiety (SO ₃ ⁻ ) that can function and generate as an acid in the polymer obtained when the compound is used as a radical polymerization initiator is increased, and the acid generating ability is improved.
In the present invention, p is preferably 1.
In addition, although several p in Formula (I) may be the same or different, it is preferable that it is the same industrially.

In formula (I), Q is a (p + 1) valent hydrocarbon group, and Q may be a single bond only when p is 1.
When p is 1, Q is a single bond or a divalent hydrocarbon group. Examples of the divalent hydrocarbon group include those similar to those having no substituent among the “divalent hydrocarbon groups optionally having a substituent” mentioned in X above. In particular, when p is 1, Q is preferably a single bond or a divalent aliphatic hydrocarbon group, more preferably a single bond or a chain or branched alkylene group, a single bond, Or a methylene group or an ethylene group is more preferable, and a single bond or an ethylene group is particularly preferable.

When p is 2, Q is a trivalent hydrocarbon group, and when p is 3, Q is a tetravalent hydrocarbon group. As the trivalent or tetravalent hydrocarbon group, among the “divalent hydrocarbon group optionally having substituent (s)” mentioned in X above, a divalent hydrocarbon group having no substituent is further selected. The thing remove | excluding one or two hydrogen atoms is mentioned, Especially, it is preferable that it is a trivalent or tetravalent aliphatic hydrocarbon group.
Specific examples in the case where Q is a (p + 1) -valent hydrocarbon group are shown below.
In addition, although several Q in Formula (I) may be the same or different, it is preferable industrially the same.

In the formula (I), q is 0 or 1. The case where q is 0 means that-(C (= O) -O) _{q- in} the formula is a single bond.
In the present invention, q is preferably 1 when the divalent linking group of X described above does not have —O—C (═O) —, and the divalent linking group of X described above is — When it has O—C (═O) —, it is preferably 0.
In addition, although several q in Formula (I) may be the same or different, it is preferable that it is the same industrially.

In formula (I), R ² is a single bond, an alkylene group which may have a substituent, or an aromatic group which may have a substituent.
The alkylene group for R ² may be linear or cyclic. Examples of such an alkylene group include the above-mentioned “linear or branched aliphatic hydrocarbon group” and “ring in the structure” in the divalent hydrocarbon group which may have a substituent of X. The same thing as "the aliphatic hydrocarbon group to contain" is mentioned. Among them, the alkylene group R ^2, preferably a linear alkylene group having 1 to 10 carbon atoms, a methylene group or an ethylene group is preferred.

The aromatic group which may have a substituent for R ² may be an aromatic hydrocarbon group or an aromatic group (heterocyclic compound) containing an atom other than a carbon atom in the ring structure. Good.
Examples of the aromatic hydrocarbon group include the same “aromatic hydrocarbon group” as described above in the divalent hydrocarbon group which may have a substituent of X, and the aromatic hydrocarbon of R ² As the group, a group obtained by further removing one or more hydrogen atoms from a phenyl group or a naphthyl group is preferable. The aromatic hydrocarbon group for R ² is 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, or an oxygen atom. It may be substituted with (═O) or the like, and is preferably substituted with a fluorine atom.
As the aromatic group containing an atom other than a carbon atom in the ring structure, a group in which two or more hydrogen atoms have been removed from a heterocyclic ring such as quinoline, pyridine, oxol, and imidazole is preferable.
Among these, R ² is preferably an aromatic group which may have a single bond or a substituent.
In addition, although several R < ² > in Formula (I) may be same or different, it is preferable that it is the same industrially.

In the formula (I), r is 0 or 1. The case where r is 0 means that — (CF ₂ ) _r — in the formula is a single bond.
In the present invention, r is preferably 1 when R ² described above is a single bond or an alkylene group which may have a substituent, and R ² described above has a substituent. In the case of a good aromatic group, 0 is preferable.
In addition, although several r in Formula (I) may be the same or different, it is preferable industrially the same.

  As the compound (I), compounds represented by the following general formulas (I1) to (I5) are preferable.

［式中、Ｒ^１、Ｚ、Ｑ、ｐ、Ａ^＋は前記同様である。Ｘ^０１は単結合又は置換基を有していてもよいアルキレン基であり、Ｒ^２１は単結合又は置換基を有していてもよいアルキレン基であり、Ｘ^０２は置換基を有していてもよいアルキレン基であり、Ｒ^２２は置換基を有していてもよい芳香族基である。式中の複数のＲ^１、Ｚ、Ｑ、ｐ、Ａ^＋、Ｘ^０１、Ｒ^２１、Ｘ^０２、Ｒ^２２はそれぞれ同じであっても異なっていてもよい。］

[Wherein, R ¹ , Z, Q, p and A ⁺ are the same as described above. X ⁰¹ is an alkylene group which may have a single bond or a substituent, R ²¹ is an alkylene group which may have a single bond or a substituent, and X ⁰² has a substituent. R ²² is an aromatic group which may have a substituent. A plurality of R ¹ , Z, Q, p, A ⁺ , X ⁰¹ , R ²¹ , X ⁰² , R ²² in the formula may be the same or different. ]

In formulas (I1) to (I5), R ¹ , Z, Q, p and A ⁺ are the same as described above.
Wherein ^{(I1) ~ (I5),} X 01 is an alkylene group which may have a single bond or a substituent. As the alkylene group which may have a substituent, the “linear or branched aliphatic hydrocarbon group” in the divalent hydrocarbon group which may have a substituent of the above X, The same thing as "the aliphatic hydrocarbon group which contains a ring in a structure" is mentioned.
X ⁰¹ is particularly preferably a single bond or an ethylene group.

In formulas (I1) to (I3), R ²¹ represents a single bond or an alkylene group which may have a substituent. The alkylene group which may have a substituent for R ²¹ is the same as the alkylene group which may have a substituent for R ² .
R ²¹ is particularly preferably a single bond or a methylene group.

In the formula (I3), X ⁰² is an alkylene group which may have a substituent, and in the divalent hydrocarbon group which may have a substituent of X, “linear or branched Examples thereof include those similar to “chain aliphatic hydrocarbon group” and “aliphatic hydrocarbon group including a ring in the structure”.
X ⁰² is particularly preferably an ethylene group.

In formulas (I4) to (I5), R ²² is an aromatic group which may have a substituent. The aromatic group which may have a substituent for R ^{22 is the same as} the aromatic group which may have a substituent for R ² .
R ²² is particularly preferably a group obtained by removing one or more hydrogen atoms from a phenyl group or a naphthyl group, or a group obtained by removing two or more hydrogen atoms from quinoline.

Specific examples of the compounds represented by the above formulas (I1) to (I5) are shown below. In the following formula, A ⁺ is the same as described above, and details will be described later.

In the formula (I), A ⁺ is a metal cation or an organic cation.
When A ⁺ is an organic cation, the compound (I) can have an acid generating ability to generate an acid upon exposure. Therefore, an acid is generated in a polymer obtained when the compound is used as a radical polymerization initiator. Ability can be granted. As will be described later, such a polymer can be suitably used for a resist composition.
When A ⁺ is a metal cation, the compound (I) can be used as an intermediate compound of a compound for a radical polymerization initiator that can impart acid generating ability to the polymer.

(Metal cation)
The metal cation of A ⁺ is not particularly limited, but is preferably an alkali metal ion, and specifically includes sodium ion, lithium ion, potassium ion and the like, and is sodium ion or lithium ion. It is more preferable.

(Organic cation)
The organic cation of A ⁺ is not particularly limited. For example, it is conventionally known as a cation moiety such as a photodegradable base used for a resist composition quencher or an onium-based acid generator of a resist composition. Organic cations can be used.
As the organic cation of A ⁺ , for example, a cation moiety represented by the following general formula (c-1) or (c-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（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, it is particularly desirable that all of R 1 "~R ^3" are aryl groups.

The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups It may or may not be substituted with a group, a halogen atom, a hydroxyl group or the like.
The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group that may be substituted for the hydrogen atom of the aryl 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. Is most preferred.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl 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 preferable, and a methoxy group and an ethoxy group are most preferable.
The halogen atom that may be substituted with the hydrogen atom of the aryl group is preferably a fluorine atom.

The alkyl group for R 1 ^{"~R 3",} is not particularly limited, for example, linear C1-10, branched or cyclic alkyl group, and the like. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.

When any two of R ¹ ″ to R ³ ″ in formula (c-1) are bonded to each other to form a ring together with the sulfur atom in the formula, a 3 to 10 membered ring is formed including the sulfur atom. It is preferable that a 5- to 7-membered ring is formed.
When any two of R ¹ ″ to R ³ ″ in formula (c-1) are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one may be an aryl group preferable. Examples of the aryl group include the same aryl groups as those described above for R ¹ ″ to R ³ ″.

  Preferable examples of the cation moiety represented by the formula (c-1) include cation moieties represented by the following formulas (I-1-1) to (I-1-32).

In formulas (I-1-19) and (I-1-20), R ⁵⁰ is a group containing an acid dissociable, dissolution inhibiting group, and will be described later in formula (p1), (p1-1) or (p2). Or an oxygen atom of —R ⁹¹ —C (═O) —O— represented by formulas (1-1) to (1-9) or (2-1) to (2-6) described later ) 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 (I-1-21), W is a divalent linking group, and examples thereof include the same as the divalent linking group for X in the formula (I). It is preferably a branched alkylene group, a divalent aliphatic cyclic group, or a divalent linking group containing a hetero atom, more preferably a linear or branched alkylene group. More preferably, it is a chain alkylene group.

In Formula (I-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 (I-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 as the divalent linking group for X in the formula (I), and an alkylene group and a divalent linking group containing an ester bond are preferable. Among them, an alkylene ^{group, -R 92 -C (= O)} -O-R 93 - is [R 92 ^an alkylene group ^{R 93} are each independently. ] 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 a group represented by (L1) to (L6) or (S1) to (S4) described later, a group similar to X ³ described later, a monocyclic group or a polycyclic group. And a group in which the bonded hydrogen atom is substituted with an oxygen atom (═O).

In the formulas (I-1-24) and (I-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 formula (I-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 groups as X in the formula (I), and combinations of these linking groups (however, those that dissociate with a base) Are excluded). 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 X in the formula (I).
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 X in the formula (I). 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.
In addition, the group having an acid dissociable group may be the acid dissociable group itself, and the acid dissociable group and a group or atom that is not dissociated by an acid (bonded to the 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 divalent linking groups as X in the formula (I).

In Formula (I-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 those similar to the divalent linking group for X in the formula (I). 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 formulas (I-1-28) and (I-1-29), R ⁹ and R ¹⁰ are each independently a phenyl group which may have a substituent, a naphthyl group or a group having 1 to 5 carbon atoms. An alkyl group, an alkoxy group, and a hydroxyl group, u is an integer of 1 to 3, and 1 or 2 is most preferable.

In formula (I-1-30), Y ¹⁰ represents a cyclic hydrocarbon group having 5 or more carbon atoms which may have a substituent, and represents an acid dissociable group which can be dissociated by the action of an acid; R ⁵⁶ and R ⁵⁷ each independently represents a hydrogen atom, an alkyl group or an aryl group, and R ⁵⁶ and R ⁵⁷ may be bonded to each other to form a ring; Y ¹¹ and Y ¹² are each independently an alkyl group. Represents a group or an aryl group, and Y ¹¹ and Y ¹² may be bonded to each other to form a ring.
Y ¹⁰ represents an acid-dissociable group which is a cyclic hydrocarbon group having 5 or more carbon atoms which may have a substituent and can be dissociated by the action of an acid. 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. The lithography properties of the film are good.
Y ¹⁰ includes a group that forms a cyclic tertiary alkyl ester with —C (R ⁵⁶ ) (R ⁵⁷ ) —C (═O) —O—.
The term “tertiary alkyl ester” as used herein refers to a cyclic hydrocarbon group having 5 or more carbon atoms on the terminal oxygen atom of —C (R ⁵⁶ ) (R ⁵⁷ ) —C (═O) —O—. A structure in which a tertiary carbon atom is bonded is shown. In this tertiary alkyl ester, when an acid acts, the bond is broken between the oxygen atom and the tertiary carbon atom.
The cyclic hydrocarbon group may have a substituent, and the carbon atom in the substituent is not included in the carbon number of “5 or more carbon atoms”.

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 substituted with a fluorine atom, an oxygen atom (= O), and the like. Is mentioned.
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. .

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 include the same alkyl groups or aryl groups as those described above 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 (I-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 Formula (I-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 to form a compound A ring may be formed together with the sulfur atom therein, and 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 It is.
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 for 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 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 A ^+, 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 an integer of 0 to 3; There, _{n 6} is an integer of 0-2. ]

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 _{1 to} n ₆ attached to R ^{44 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{41 to} R ⁴⁶ may be the same or different.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.

In the present invention, as the compound (I), compounds represented by the above formulas (I1) to (I5) are preferable, and a compound represented by (I1) is particularly preferable. Moreover, as an organic cation of A ^<+>, the organic cation represented by the said Formula (c-1)-(c-3) is preferable, and the organic cation represented by the said Formula (c-1) is especially preferable.
Although the manufacturing method of compound (I) of this invention is not specifically limited, It mentions later as a 3rd aspect concretely.

≪Radical polymerization initiator≫
The radical polymerization initiator according to the second aspect of the present invention comprises the compound according to the first aspect (compound (I)) represented by the general formula (I).
The radical polymerization initiator can be used as a polymerization initiator for polymerizing monomers in a radical polymerization reaction for synthesizing a polymer compound. In addition, the radical polymerization initiator of the present invention has an acid generating ability when it has an organic cation as A ⁺ in the general formula (I), and can impart the acid generating ability to a compound obtained by polymerization. it can. Therefore, the radical polymerization initiator of the present invention can be suitably used for radical polymerization of a polymer used in a chemically amplified resist composition.
The monomer to be radically polymerized by the radical polymerization initiator is not particularly limited as long as it is capable of radical polymerization, and is appropriately selected according to the polymer to be produced. As a monomer to be polymerized by the radical polymerization initiator of the present invention, an acrylate monomer, a vinyl monomer, or a styrene monomer is preferable, and an acrylate monomer is particularly preferable. . Examples of the acrylate monomer include monomers that induce structural units (a1) to (a3) described later.

≪Method for producing compound≫
The third aspect of the present invention is a process for producing the compound of the first aspect represented by the general formula (I) (compound (I)), which is represented by the following general formula (i-1). A compound (hereinafter sometimes referred to as “compound (i-1)”) and a compound represented by the following general formula (i-2) (hereinafter sometimes referred to as “compound (i-2)”) And a step of reacting.

［式中、Ｒ^１、Ｚ、Ｘ、Ｑ、ｐ、ｑ、Ｒ^２、ｒ、Ａ^＋はそれぞれ前記同様であり、Ｂ^１、Ｂ^２はそれぞれ独立にＨ又はＯＨである。式中の複数のＲ^１、Ｚ、Ｘ、ｐ、Ｑ、Ｂ^１はそれぞれ同じであっても異なっていてもよい。］

[Wherein, R ¹ , Z, X, Q, p, q, R ² , r, and A ⁺ are the same as defined above, and B ¹ and B ² are each independently H or OH. A plurality of R ¹ , Z, X, p, Q, and B ¹ in the formula may be the same or different. ]

  Although the manufacturing method of the compound of this invention will not be specifically limited if the process of making a compound (i-1) and (i-2) react is included, For example, a compound (i-1) and Compound (I) can be produced by reacting compound (i-2) with appropriate conditions.

In formula (i-1), R ¹ , Z, X, Q, and p are the same as described above, and B ¹ is H or OH. And if Q is an oxygen atom at the terminal bound to B ^1, Q is a single bond, and when X is an oxygen atom at the terminal bound to B ^1, it is preferred that B ¹ represents an H. On the other hand, and if Q does not have an oxygen atom at the terminal bound to B ^1, Q is a single bond, and if X does not have an oxygen atom at the terminal bound to B ^1, it B ¹ represents an OH Is preferred.
In formula (i-2), q, R ² , r and A ⁺ are the same as described above, and B ² is H or OH. When q is 1, B ² is preferably H. On the other hand, when q is 0, B ² is preferably OH.

As compound (i-1) and compound (i-2), commercially available compounds may be used or synthesized.
The method for obtaining compound (I) by reacting compound (i-1) with compound (i-2) is not particularly limited. For example, compound (i-2) in the presence of a condensing agent or a base is used. And the compound (i-1) are reacted in an organic solvent, and then the reaction mixture is washed and recovered.

The condensing agent in the said reaction is not specifically limited, For example, the compound containing carbodiimide groups, such as diisopropyl carbodiimide, is mentioned, These may be used individually by 1 type, or may use 2 or more types together. The amount to be used is preferably about 0.01 to 10 mol per 1 mol of compound (i-2).
The base in the above reaction is not particularly limited, and examples thereof include tertiary amines such as potassium carbonate and triethylamine, and aromatic amines such as pyridine. These may be used alone. More than one species may be used in combination. The amount of the base used is usually preferably about 0.01 to 10 mol with respect to 1 mol of compound (i-2).
As the organic solvent in the above reaction, a chlorinated hydrocarbon solvent such as dichloromethane is preferable, and the amount used is preferably 0.5 to 100 parts by mass with respect to compound (i-2). More preferably, it is 20 parts by mass. A solvent may be used individually by 1 type and may use 2 or more types together.
When p is 1, the amount of compound (i-2) used in the above reaction is usually preferably about 0.5 to 5 mol, preferably 0.8 to 4 mol, relative to 1 mol of compound (i-1). The degree is more preferable.

The reaction time in the above reaction varies depending on the reactivity between the compound (i-1) and the compound (i-2), the reaction temperature, etc., but is usually preferably 1 to 80 hours, more preferably 3 to 60 hours. .
The reaction temperature in the above reaction is preferably 20 ° C to 200 ° C, more preferably about 20 ° C to 150 ° C.

  After completion of the reaction, the compound (I) in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more thereof. it can.

The structure of the compound (I) obtained as described above is as follows: ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum method, mass It can be confirmed by a general organic analysis method such as analysis (MS) method, elemental analysis method or X-ray crystal diffraction method.

≪Polymer≫
The fourth aspect of the present invention is a polymer having a group represented by the following general formula (I-1) at at least one end of the main chain.

［式中、Ｒ^１は炭素数１〜１０の炭化水素基であり、Ｚは炭素数１〜１０の炭化水素基又はシアノ基であり、Ｒ^１とＺとは相互に結合して環を形成していてもよい。Ｘは２価の連結基であって、−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−、及び−ＮＨ−Ｃ（＝ＮＨ）−のいずれかを、少なくとも式中のＱと接する末端に有する。ｐは１〜３の整数である。Ｑは（ｐ＋１）価の炭化水素基であり、ｐが１の場合のみ、Ｑは単結合であってもよい。Ｒ^２は単結合、置換基を有していてもよいアルキレン基、又は置換基を有していてもよい芳香族基であり、ｑ、ｒはそれぞれ独立に０又は１であり、Ｍ^＋は有機カチオンである。］

[Wherein, R ¹ is a hydrocarbon group having 1 to 10 carbon atoms, Z is a hydrocarbon group having 1 to 10 carbon atoms or a cyano group, and R ¹ and Z are bonded to each other to form a ring. You may do it. X is a divalent linking group, and at least one of —O—C (═O) —, —NH—C (═O) —, and —NH—C (═NH) — It is at the end that contacts Q. p is an integer of 1 to 3. Q is a (p + 1) -valent hydrocarbon group, and Q may be a single bond only when p is 1. R ² is a single bond, an optionally substituted alkylene group, or an optionally substituted aromatic group, q and r are each independently 0 or 1, and M ⁺ is Organic cation. ]

In the formula (I-1), R ¹ , Z, X, p, Q, R ² , q, and r are R ¹ , Z, X, p in the formula (I) described in the compound of the first aspect. , Q, R ² , q, r.
In formula (I-1), M ⁺ is an organic cation and is the same as the organic cation of A ⁺ in formula (I) described in the compound of the first embodiment.

  Since the polymer of the present invention has a terminal group (I-1), it has an acid generating ability to generate an acid upon exposure. That is, the terminal group (I-1) has a sulfonium salt moiety at the terminal, so that sulfonic acid is generated by exposure.

The polymer of the present invention only needs to have a terminal group (I-1) at at least one end of the main chain. Depending on the application, known ones can be used.
The polymer of the present invention is useful for a resist composition. The resist composition to which the polymer of the present invention is blended is not particularly limited, but includes a base material component whose solubility in an alkali developer is changed by the action of an acid, and an acid generator component that generates an acid upon exposure. A chemically amplified resist composition is preferable.
The polymer of the present invention is particularly useful as a base component of a chemically amplified resist composition or as an additive component arbitrarily blended in the resist composition, and used as a base component. Is particularly preferred. The configuration of the polymer used as the base component will be described in detail in the component (A1) of the resist composition of the fifth aspect of the present invention described later.

As the method for producing the polymer of the present invention having the terminal group (I-1) at at least one end of the main chain, a desired method is obtained by radical polymerization using the radical polymerization initiator of the second aspect of the present invention described above. A method of polymerizing monomers is preferred. That is, the polymer of the fourth aspect of the present invention is preferably a radical polymer obtained by radical polymerization using the radical polymerization initiator of the second aspect of the present invention.
The monomer to be radically polymerized is not particularly limited as long as it can be radically polymerized, and a monomer for deriving a structural unit constituting the polymer is appropriately selected according to the polymer to be produced.
The radical polymerization can be carried out using a known method except that the radical polymerization initiator of the present invention is used as a radical polymerization initiator.
In radical polymerization, the radical polymerization initiator of the present invention may be used alone or in combination of two or more.

In addition, when the radical polymerization initiator of the second aspect of the present invention has a metal cation as A ⁺ which is a cation part, a salt is previously formed between the radical polymerization initiator and an onium salt having a desired organic cation. By exchanging, a radical polymerization initiator having M ⁺ which is an organic cation can be obtained. Salt exchange can be performed by a conventional method.

Further, as another method for producing the polymer of the present invention, by using the compound (I0) represented by the following general formula (I0) as a radical polymerization initiator, the following general formula ( polymer having a group represented by I-01) (to give a precursor polymer), the precursor to the main chain terminal groups of the body weight polymer ^{_{"- (OCO) q -R 2 -}} (CF 2) r -SO ₃ ^- A ⁺ ”(q, R ² , r, A ⁺ are the same as described above) is introduced (a hydrogen atom at the end of the main chain is replaced).
As compound (I-01), known compounds can be used.
^{_{"- (OCO) q -R 2 -}} (CF 2) r -SO 3 - A + " introduction can be carried out by a conventional method, for example, precursor polymer and the following general formula ( It can be carried out by reacting the compound (i-02) represented by i-02). The reaction can be carried out in the same manner as described in the method for producing compound (I) of the third aspect.

［式中、Ｒ^１、Ｚ、Ｘ、Ｑ、ｐ、ｑ、Ｒ^２、ｒ、Ｍ^＋、Ｂ^１、Ｂ^２はそれぞれ前記同様である。］

[Wherein R ¹ , Z, X, Q, p, q, R ² , r, M ⁺ , B ¹ and B ² are the same as defined above. ]

≪Resist composition≫
The resist composition according to the fifth aspect of the present invention contains the polymer according to the fourth aspect. A resist film formed using such a resist composition has a function of generating an acid upon exposure by containing the polymer of the present invention.
Therefore, when the resist film contains the polymer of the present invention, it is possible to form a pattern using a component whose solubility is changed by the action of an acid even when an acid generator is not included separately. . Moreover, also when it contains an acid generator other than the polymer of this invention, a sensitivity can be improved compared with the case where the polymer of this invention is not contained.

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.

Further, the resist composition of the present invention may be a non-chemical amplification type or a chemical amplification type. In the present invention, a chemically amplified resist composition is particularly preferable because a resist pattern can be formed with high sensitivity and high resolution.
In general, a chemically amplified resist composition generally contains a base material component whose solubility in a developer is changed by the action of an acid and an acid generator component that generates an acid upon exposure. When the resist composition is exposed, an acid is generated from the acid generator component, and the solubility of the base component in the developer is changed by the action of the acid. Therefore, in the formation of the resist pattern, when the resist film formed using the resist composition is selectively exposed, the solubility of the exposed portion in the developer changes (increased in the case of positive type, and in the case of negative type). On the other hand, since the solubility of the unexposed portion in the alkaline developer does not change, the resist pattern is formed by developing this.

As described above, in the chemically amplified resist composition, a base material component whose solubility in a developer is changed by the action of an acid is usually used.
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”.

The resist composition of the present invention may contain the polymer of the fourth aspect of the present invention as a resin constituting the base component whose solubility in the developer is changed by the action of an acid; In addition to the resin constituting the component, the polymer of the fourth aspect of the present invention may be contained. That is, the polymer used in the resist composition of the present invention may be one whose solubility in a developer is changed by the action of an acid, or may be other than that.
Especially, it is preferable that the polymer of this invention used for the resist composition of this invention changes the solubility with respect to a developing solution by the effect | action of an acid, and is used as a base-material component. As described above, the polymer of the fourth aspect has an acid generating ability to generate sulfonic acid by the action of an acid at the terminal. In addition, since the solubility of the polymer in the developer is changed by the action of an acid, the acid generated by exposure and the site contributing to the solubility change by the acid in the polymer (specifically, For example, a structural unit (a1) described later) is uniformly distributed in the resist film, and an acid is uniformly generated from the polymer in the exposed portion, so that the solubility of the polymer itself is suitably changed. Good lithography characteristics can be obtained.

  That is, the resist composition of the present invention contains a base component (A) (hereinafter referred to as “component (A)”) that changes its solubility in a developing solution by the action of an acid and generates an acid upon exposure. And it is preferable that the said (A) component contains the polymer of a 4th aspect. Hereinafter, the resist composition containing the polymer of the present invention as the component (A) will be described.

<(A) component>
When the resist composition of the present invention is a “negative resist composition for an alkali development process” that forms a negative pattern in an alkali development process, a base component that is soluble in an alkali developer is used as the component (A). Furthermore, a crosslinking agent component is blended.
When an acid is generated from the polymer of the present invention contained in the component (A) by exposure, the negative resist composition for alkali development process acts between the base component and the crosslinking agent component when the acid acts. Crosslinking occurs and changes to poorly soluble in an alkaline developer. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the negative resist composition on a support is selectively exposed, the exposed portion turns into poorly soluble in an alkaline developer, while not yet exposed. Since the exposed portion remains soluble in the alkali developer and does not change, a resist pattern can be formed by alkali development.
As the component (A) of the negative resist composition for an alkali development process, a resin that is soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”) is usually used.
Examples of the alkali-soluble resin include α- (hydroxyalkyl) acrylic acid or α- (hydroxyalkyl) acrylic acid alkyl ester (preferably having 1 to 5 carbon atoms) disclosed in, for example, JP-A-2000-206694. A resin having a unit derived from at least one selected from alkyl ester); a hydrogen atom bonded to a carbon atom at the α-position having a sulfonamide group, which is disclosed in US Pat. No. 6,949,325, is substituted with a substituent. Acrylic resin or polycycloolefin resin that may be contained; disclosed in US Pat. No. 6,949,325; The hydrogen atom bonded to the atom may be substituted with a substituent. Le resin; Japanese Patent disclosed in 2006-259582, JP-polycycloolefin resins having fluorinated alcohol, with minimal swelling can formation of a satisfactory resist pattern.
The α- (hydroxyalkyl) acrylic acid is a hydrogen atom bonded to the α-position carbon atom to which the carboxy group is bonded, among the acrylic acid in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. One or both of acrylic acid having an atom bonded thereto and α-hydroxyalkylacrylic acid having a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) bonded to the α-position carbon atom are shown. .
As the crosslinking agent component, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, a melamine crosslinking agent, or the like because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent component is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the resist composition of the present invention is a resist composition that forms a positive pattern in an alkali development process and a negative pattern in a solvent development process, the component (A) has increased polarity due to the action of an acid. It is preferable to use the base material component (A0) (hereinafter referred to as “(A0) component”). By using the component (A0), the polarity of the base material component changes before and after exposure, so that good development contrast can be obtained not only in the alkali development process but also in the solvent development process.
When the alkali development process is applied, the component (A0) is hardly soluble in an alkali developer before exposure, and when acid is generated from the polymer of the present invention contained in the component (A) by exposure, The polarity is increased by the action of the acid, and the solubility in an alkaline developer is increased. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the resist composition on a support is selectively exposed, the exposed portion changes from slightly soluble to soluble in an alkaline developer. Since the unexposed portion remains hardly soluble in alkali and does not change, a positive pattern can be formed by alkali development.
When applying a solvent development process, the component (A0) is highly soluble in an organic developer before exposure, and the polymer (A1) of the present invention contains the component (A) upon exposure. When an acid is generated from such as, the polarity is increased by the action of the acid, and the solubility in an organic developer is decreased. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the resist composition on the support is selectively exposed, the exposed portion changes from soluble to poorly soluble in an organic developer. On the other hand, since the unexposed portion remains soluble and does not change, by developing with an organic developer, a contrast can be provided between the exposed portion and the unexposed portion, and a negative pattern can be formed.

In the resist composition of the present invention, the component (A) is preferably a base material component ((A0) component) whose polarity is increased by the action of an acid. That is, the resist composition of the present invention is preferably a chemically amplified resist composition that becomes positive in the alkali development process and negative in the solvent development process.
In the resist composition of the present invention, the polymer of the present invention contained in the component (A) is preferably a resin component whose polarity is increased by the action of an acid. That is, the component (A) of the present invention has a resin component (A1) (hereinafter sometimes referred to as “component (A1)”) made of the polymer of the present invention, having increased polarity due to the action of an acid. preferable.

[(A1) component]
The component (A1) may be any component as long as it has the terminal group (I-1) at at least one end of the main chain. The components other than the terminal group are usually groups for chemically amplified resists. The same configuration as the resin component (base resin) used as the material component can be employed.
In the present invention, the component (A1) preferably has a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent.
In the resist composition of the present invention, in particular, the component (A1) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, It is preferable to have a structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid.
In addition to the structural unit (a1), the component (A1) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. A structural unit derived from an acrylate ester containing an —SO ₂ — containing cyclic group and a hydrogen atom bonded to the carbon atom at the α-position, which may be substituted with a substituent, It is preferable to have at least one structural unit (a2) selected from the group consisting of structural units containing a containing cyclic group.
In addition to the structural unit (a1) or the structural units (a1) and (a2), the component (A1) further has a hydrogen atom bonded to the α-position carbon atom substituted with a substituent. The structural unit may be a structural unit derived from an acrylate ester which may be included and includes a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group.

(Structural unit (a1))
The structural unit (a1) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and the acid decomposition whose polarity is increased by the action of an acid A structural unit containing a sex group.
The “acid-decomposable group” has an acid-decomposability that at least a part of bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid generated from the polymer (A1) of the present invention by exposure. It is group which has.
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 between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid (such as an acid generated from the polymer (A1) of the present invention by exposure). It is a group having acid dissociability that can be cleaved. The acid-dissociable group constituting the acid-decomposable group needs to be a group having a lower polarity than the polar group generated by dissociation of the acid-dissociable group. Is dissociated, a polar group having a polarity higher than that of the acid dissociable group is generated to increase the polarity. As a result, the polarity of the entire component (A1) increases. Due to the increase in polarity, the solubility in an alkaline developer is relatively increased if an alkali development process is applied. On the other hand, if a solvent development process is applied, the solubility in an organic developer containing an organic solvent is reduced.

  As the acid dissociable group in the structural unit (a1), those proposed so far as the acid dissociable group of the base resin for a chemically amplified resist 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 is 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 ) -O-) shows a structure in which the tertiary carbon atom of the chain-like or cyclic alkyl group is bonded to the terminal oxygen atom. 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, thereby increasing the polarity of the component (A1).
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, the term “aliphatic branched” in the claims and the specification means that it has 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.
As the aliphatic branched acid dissociable group, a tertiary alkyl group having 4 to 8 carbon atoms is preferable, and specific examples thereof include a tert-butyl group, a tert-pentyl group, and a tert-heptyl group.

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a1) may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like. Is mentioned.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The “aliphatic cyclic group” is preferably a polycyclic group.
Examples of the aliphatic cyclic group include a monocycloalkane, a bicycloalkane, and a tricyclo 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. Examples thereof include groups in which one 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 one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. .

Examples of the acid-dissociable group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group. Examples thereof include 2-methyl-2-adamantyl group and 2-ethyl-2-adamantyl group such as those represented by 1) to (1-9).
As the aliphatic branched acid dissociable group, adamantyl group, cyclohexyl group, cyclopentyl group, norbornyl group, tricyclodecyl group as shown in the following general formulas (2-1) to (2-6) And a group having an aliphatic cyclic group such as a tetracyclododecyl group and a branched alkylene group having a tertiary carbon atom bonded thereto.

［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、Ｒ^１６はそれぞれ独立してアルキル基（直鎖状、分岐鎖状のいずれでもよく、好ましくは炭素数１〜５である）を示す。］

[Wherein, R ¹⁵ and R ¹⁶ each independently represents an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms). ]

The alkyl group for R ¹⁴ is preferably a linear or branched alkyl group.
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.
Examples of the alkyl group for R ^{15 to} R ¹⁶ include the same alkyl groups as those 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. Then, 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, and a carboxy group, a hydroxyl group, etc. By forming the OH-containing polar group, the polarity of the component (A1) is increased.
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、ｎ０１は０〜３の整数を表し、Ｙ^１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 represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, n01 represents an integer of 0 to 3 and Y ¹ represents an alkyl having 1 to 5 carbon atoms. Represents a group or an aliphatic cyclic group. ]

In the above formula, n01 is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the alkyl group having 1 to 5 carbon atoms of R ¹ ′ and R ² ′ include the same as the alkyl group having 1 to 5 carbon atoms of R, and a methyl group or an ethyl group is preferable, and a methyl group is the most preferable. preferable.
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’、ｎ０１、Ｙ^１は上記と同様である。］

[Wherein, R ¹ ′, n01 and Y ¹ are the same as described above. ]

Examples of the alkyl group having 1 to 5 carbon atoms of Y ¹ include the same as the alkyl group having 1 to 5 carbon atoms of R.
As the aliphatic cyclic group for Y ¹ , it can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups conventionally proposed in a number of ArF resists and the like. The same thing as a "cyclic group" can be illustrated.

  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また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、分岐鎖状また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または分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端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 represent 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 be each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of 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, are included. Examples include a group excluding a hydrogen atom. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the above formula, 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 the end of R ¹⁹ and R ¹⁷ The terminal may be bonded.
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.

  As the structural unit (a1), one or more selected from the group consisting of structural units represented by the following general formula (a1-0-1) and structural units represented by the following general formula (a1-0-2): Is preferably used.

［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を示し、Ｘ^１’は酸解離性基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and X ¹ ′ represents an acid dissociable group. ]

［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を示し、Ｘ^２’は酸解離性基を示し、Ｙ^２は２価の連結基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, X ² ′ represents an acid dissociable group, and Y ² represents a divalent linking group. Indicates. ]

In general formula (a1-0-1), R is the same as defined above.
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. Alkyl ester type acid dissociable groups are preferred.

In general formula (a1-0-2), R is the same as defined above.
X ² ′ is the same as X ¹ ′ in formula (a1-0-1).
Examples of the divalent linking group for Y ² include those similar to the divalent linking group for X in the formula (I).

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

［式中、Ｘ’は第３級アルキルエステル型酸解離性基を表し、Ｙ^１は炭素数１〜５のアルキル基、または脂肪族環式基を表し；ｎ０１は０〜３の整数を表し；Ｙ^２は２価の連結基を表し；Ｒは前記と同じであり、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のアルキル基を表す。］

[Wherein, X ′ represents a tertiary alkyl ester type acid dissociable group, Y ¹ represents an alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; n01 represents an integer of 0 to 3] Y ² represents a divalent linking group; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; ]

In the above formula, X ′ is the same as the tertiary alkyl ester-type acid dissociable group exemplified in X ¹ ′.
R ¹ ', ^{R 2',} as is n01, ^{Y 1,} respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable group" described above ^{(p1) ', R 2'} , n01, Y 1 The same thing is mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in the general formula (a1-0-2).

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.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
Among these, the structural unit represented by general formula (a1-1), (a1-2) or (a1-3) is preferable, and specifically, (a1-1-1) to (a1-1-4). , (A1-1-20) to (a1-1-23), (a1-2-1) to (a1-2-24) and (a1-3-25) to (a1-3-28) It is more preferable to use at least one selected from the group.
Furthermore, as the structural unit (a1), in particular, the following general formula (a1-1-1-) including structural units of the formulas (a1-1-1) to (a1-1-3) and (a1-1-26) 01), formulas (a1-1-16) to (a1-1-17), formulas (a1-1-20) to (a1-1-23) and (a1-1-32) Comprehensive structural units including structural units represented by the following general formula (a1-1-02), formulas (a1-2-3), (a1-2-6) and (a1-2-7) Represented by the following general formula (a1-1-03), the following general formula including the structural units of the formulas (a1-2-3), (a1-2-6) and (a1-2-7) What is represented by (a1-1-04), and is represented by the following general formula (a1-3-01) including the structural units of formulas (a1-3-25) to (a1-3-26) The following general formula (a1-3-02) or structural formulas (a1-3-29) to (a1-3) including structural units of formulas (a1-3-27) to (a1-3-28) What is represented by the following general formula (a1-3-03) including the structural unit of -30) is also preferable.

[式中、Ｒはそれぞれ独立に水素原子、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を示し、Ｒ^１１は炭素数１〜５のアルキル基を示す。Ｒ^１２は炭素数１〜７のアルキル基を示す。ｈは１〜６の整数を表す。Ｒ、Ｒ^１’、Ｒ^２’、ｎ０１、Ｒ^１５、Ｒ^１６は前記同様である。]

[Wherein, R independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R ¹¹ represents an alkyl group having 1 to 5 carbon atoms. R ¹² represents an alkyl group having 1 to 7 carbon atoms. h represents an integer of 1 to 6. R, R ¹ ′, R ^{2 ′} , n01, R ¹⁵ , and R ¹⁶ are the same as described above. ]

In general formula (a1-1-01), R is the same as defined above. The alkyl group having 1 to 5 carbon atoms of R ¹¹ is the same as the alkyl group having 1 to 5 carbon atoms in R, and is preferably a methyl group, an ethyl group, or an isopropyl group.

In general formula (a1-1-02), R is the same as defined above. The alkyl group having 1 to 5 carbon atoms of R ¹² is the same as the alkyl group having 1 to 5 carbon atoms in R, and is preferably a methyl group, an ethyl group, or an isopropyl group. h is preferably 1 or 2, and most preferably 2.
In general formula (a1-1-03), R, R ¹ ′, R ^{2 ′} , and n01 are the same as described above.
In general formula (a1-1-04), R, R ¹⁵ and R ¹⁶ are the same as described above.

[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を示し；Ｒ^１４は前記同様であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数である。]

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ¹⁴ is the same as described above; R ¹³ is a hydrogen atom or a methyl group; a is an integer of 1-10. ]

[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を示し；Ｒ^１４は前記同様であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数であり、ｎ’は１〜６の整数である。]

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ¹⁴ is the same as described above; R ¹³ is a hydrogen atom or a methyl group; a is an integer of 1 to 10, and n ′ is an integer of 1 to 6. ]

［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、ｎ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 n is an integer of 0 to 3] is there.]

In the general formulas (a1-3-01) to (a1-3-03), R is the same as described above.
R ¹³ is preferably a hydrogen atom.
n ′ is preferably 1 or 2, and most preferably 2.
a is preferably an integer of 1 to 8, more preferably an integer of 2 to 5, and most preferably 2.
Examples of the divalent linking group in Y ² ′ and Y ² ″ include the same groups as Y ² in the general 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 for X ′ include the same groups as described above, preferably a tertiary alkyl ester-type acid-dissociable group, and a tertiary carbon atom on the ring skeleton of the cyclic alkyl group described above. The group represented by formula (1-1) is particularly preferable.
n is an integer of 0 to 3, and n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.

  In the component (A1), the proportion of the structural unit (a1) is preferably from 5 to 80 mol%, more preferably from 10 to 75 mol%, more preferably from 15 to 70 mol%, based on all structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

(Structural unit (a2))
The structural unit (a2) 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. A structural unit derived from a structural unit (hereinafter referred to as a structural unit (a2 ^S )) and an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, It is at least one structural unit selected from the group consisting of structural units containing a cyclic group (hereinafter referred to as structural unit (a2 ^L )).
When the structural unit (a2) contains a —SO ₂ — containing cyclic group or a lactone cyclic group, the adhesion of the resist film formed using the resist composition containing the component (A1) 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 the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and the —SO ₂ -containing cyclic group is Containing 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, preferably 4 to 20 carbon atoms, more preferably 4 to 15 carbon atoms, and particularly preferably 4 to 12 carbon atoms. . However, the carbon number is the number of carbon atoms constituting the ring skeleton, and does not include the carbon number in the substituent.
The —SO ₂ — containing cyclic group may be an —SO ₂ — containing aliphatic cyclic group or an —SO ₂ — containing aromatic cyclic group. Preferably -SO ₂ - containing aliphatic cyclic group.
The —SO ₂ -containing aliphatic cyclic group includes at least a hydrogen atom from an aliphatic hydrocarbon ring in which a part of carbon atoms constituting the ring skeleton is substituted with —SO ₂ — or —O—SO ₂ —. One group is excluded. More specifically, a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which —CH ₂ — constituting the ring skeleton is substituted with —SO ₂ —, —CH ₂ — constituting the ring And a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which CH ₂ — is substituted with —O—SO ₂ —.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms are removed from a monocycloalkane having 3 to 6 carbon atoms. Examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane. , Tricyclodecane, tetracyclododecane and the like.

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

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

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

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

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

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

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

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

In formula (a2-0), R 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.
The divalent linking group for R ²⁹ is not particularly limited, and examples thereof include those similar to the divalent linking group for X in the formula (I). 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 X in the formula (I).
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 preferable as X in the formula (I). 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 the above formulas -A-O-B-,-[A-C (= O) -O] _m A group represented by —B— or —A—O—C (═O) —B— is more preferable.
Among them, preferred is a group represented by the formula -A-O-C (= O ) -B-, - represented by _{- (CH 2) c -C (} = O) -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 (a2-1-11) or (a2-1-12) shown below is particularly desirable, and represented by formula (a2-1-12) 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 (a2-1-11), 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 formula (a2-1-12), a structural unit represented by general formula (a2-1-12a) or (a2-1-12b) shown below is particularly desirable.

［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 It is.
Here, the lactone-containing cyclic group refers to a cyclic group containing a ring (lactone ring) containing —O—C (O) — in the ring skeleton. The lactone ring is counted as the first ring. When only the lactone ring is present, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone cyclic group in the structural unit (a2 ^L ) is not particularly limited, and any one can be used. Specifically, the lactone-containing monocyclic group is a group obtained by removing one hydrogen atom from a 4- to 6-membered ring lactone, such as a group obtained by removing one hydrogen atom from β-propionolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed and a group in which one hydrogen atom has been removed from δ-valerolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
Examples of the structural unit (a2 ^L ) include those obtained by substituting R ²⁸ in the general formula (a2-0) with a lactone-containing cyclic group, and more specifically, the following general formula (a2- The structural unit represented by 1)-(a2-5) 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、炭素数１〜５のアルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”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 having 1 to 5 carbon atoms, carbon An alkoxy group of 1 to 5 or —COOR ″, R ″ is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group, and s ″ is an integer of 0 to 2; A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom; m is 0 or 1. ]

R in the general formulas (a2-1) to (a2-5) is the same as described above.
Examples of the alkyl group having 1 to 5 carbon atoms of R ′ include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group.
Examples of the alkoxy group having 1 to 5 carbon atoms of R ′ include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group.
R ′ is preferably a hydrogen atom in view of industrial availability.
The alkyl group in R ″ may be linear, branched or cyclic.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
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 Or a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group Specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Etc.
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.

Moreover, as the structural unit (a2 ^L ), structural units represented by the following formulas (a2-6) to (a2-7) are also preferable.

［式中、Ｒ、Ｒ^２９は前記同様である。］

[Wherein, R and R ²⁹ are the same as defined above. ]

In the component (A1), as the structural unit (a2), one type may be used alone, 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). Is more preferable, it is more preferable that it is 10-65 mol%, and 10-60 mol% is especially preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units, such as various kinds of DOF, CDU, etc. The lithography characteristics and pattern shape of the film are improved.

(Structural unit (a3))
The structural unit (a3) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and includes a polar group-containing aliphatic hydrocarbon group It is a structural unit.
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) increases, which contributes to the improvement of resolution.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). It is done.
As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the following formula (a3-2), and the following formula The structural unit represented by (a3-3) is preferable.

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

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

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

  In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

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

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
When the component (A1) contains the structural unit (a3), the proportion of the structural unit (a3) in the component (A1) is 1 to 50 mol% with respect to all the structural units constituting the component (A1). It is preferably 3 to 45 mol%, more preferably 5 to 40 mol%. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

(Other structural units)
The component (A1) may contain other structural units (hereinafter referred to as structural unit (a4)) other than the structural units (a1) to (a3) as long as the effects of the present invention are not impaired.
The structural unit (a4) is not particularly limited as long as it is another structural unit that is not classified into the structural units (a1) to (a3) described above, and is for ArF excimer laser and KrF excimer laser (preferably ArF excimer). A number of hitherto known materials can be used for resist resins such as lasers.
As the structural unit (a4), for example, an acid non-dissociable aliphatic polycyclic group is included, and the structural unit (a4) is derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. A structural unit derived from a structural unit, a styrene monomer, a vinyl naphthalene monomer, or the like is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

［式中、Ｒは前記と同じである。］

[Wherein, R is the same as defined above. ]

As the structural unit (a4), one type may be used alone, or two or more types may be used in combination.
When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) is preferably 1 to 20 mol% with respect to the total of all the structural units constituting the component (A1). 15 mol% is more preferable and 1-10 mol% is further more preferable.

The component (A1) is preferably a copolymer containing the structural unit (a1), and more preferably a copolymer containing the structural units (a1) and (a2).
Examples of such a copolymer include a copolymer composed of structural units (a1) and (a2); a copolymer composed of structural units (a1) and (a3); a structural unit (a1), (a2) and (a3). Examples of such a copolymer include:
In the present invention, the component (A1) preferably includes a combination of structural units represented by the following general formulas (A1-11) to (A1-23). In the following general formula, R, R ^{11 to} R ¹⁶ , R ²⁹ , s ″, R ^{1 ′} , R ^{2 ′} , n01, j, e, A ′, a, and h are the same as defined above. A plurality of R may be the same or different.

The mass average molecular weight (Mw) (polystyrene conversion standard by gel permeation chromatography) of the polymer compound contained in the component (A1) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 40000. Preferably, 2500 to 30000 is most preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Moreover, the dispersity (Mw / Mn) of the polymer compound contained in the component (A1) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0. Preferably, 1.2 to 2.5 is most preferable. In addition, Mn shows a number average molecular weight.

In the component (A), as the component (A1), one type may be used alone, or two or more types may be used in combination.
The proportion of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, still more preferably 75% by mass or more, and 100% by mass with respect to the total mass of the component (A). It may be. When the ratio is 25% by mass or more, effects such as lithography characteristics are improved.
The component (A1) can be produced by polymerizing a monomer that induces each structural unit constituting the component (A1) by radical polymerization using the radical polymerization initiator of the present invention as described above. it can. Monomers (monomers) for deriving each structural unit may be synthesized or commercially available.

[(A2) component]
In the resist composition of the present invention, as a component (A), a base material component (hereinafter referred to as “component (A2)”) which does not correspond to the component (A1) and whose solubility in a developing solution is changed by the action of an acid. You may contain.
The component (A2) is preferably a low molecular compound having a molecular weight of 500 or more and less than 2500 and having an acid dissociable group and a hydrophilic group as exemplified in the description of the component (A1). Specific examples include those in which some of the hydrogen atoms of the hydroxyl group of the compound having a plurality of phenol skeletons are substituted with the acid dissociable group.
The component (A2) is, for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a sensitizer in a non-chemically amplified g-line or i-line resist or a heat resistance improver. Those substituted with a functional group are preferred and can be arbitrarily used.
Examples of such low molecular weight phenol compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyph Phenylmethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl- 4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, Examples include 2 to 6 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol and xylenol. Of course, it is not limited to these. In particular, a phenol compound having 2 to 6 triphenylmethane skeletons is preferable because of excellent resolution and LWR.
The acid dissociable group is not particularly limited, and examples thereof include those described above.

Moreover, it is also preferable to use the resin component which does not correspond to the said (A1) component as (A2) component. Specifically, the resin component not corresponding to the component (A1) does not correspond to the polymer of the fourth aspect of the present invention, for example, other than the radical polymerization initiator of the second aspect of the present invention. And a polymer produced using a known radical polymerization initiator. Although the structure of this polymer is not specifically limited, For example, what has the said structural unit (a1)-(a3) is preferable.
(A2) A component may be used individually by 1 type and may be used in combination of 2 or more type.

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

<Optional component>
The resist composition of the present invention may further contain an acid generator component (B) (hereinafter referred to as (B) component) that generates an acid upon irradiation with radiation.
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, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、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良いアルキル基、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).

In formulas (b-1) to (b-2), R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.
The alkyl group for R ⁴ ″ may be linear, branched or cyclic.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
Examples of the halogenated alkyl group for R ⁴ ″ include groups in which part or all of the hydrogen atoms of the linear, branched, or cyclic alkyl group have been substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. 50 to 100% is preferable, and 100% is most preferable. The higher the halogenation rate, the better the acid strength.
The aryl group for R ⁴ ″ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group in R ⁴ ″ is preferably an alkenyl group having 2 to 10 carbon atoms.
In the above R ⁴ ″, “optionally substituted” 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 heteroatom, an alkyl group, and a formula: X ³ -Q ^1- [wherein Q ¹ 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.

In the group represented by X ³ -Q ^1- , Q ¹ is a divalent linking group containing an oxygen atom.
Q ¹ may contain an atom other than an oxygen atom. 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.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —O—C (═O) — , R ^{91 to} R ⁹³ are each independently an alkylene group.) And the like.
The alkylene group for R ^{91 to} R ⁹³ 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 ¹ is preferably a divalent linking group containing an ester bond or an ether bond, and in particular, —R ⁹¹ —O—, —R ⁹² —O—C (═O) — or —C (═O) — O—R ⁹³ —O—C (═O) — is preferred.

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

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

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

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

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

[Wherein, 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 carbon. An alkylene group of 1 to 5 and m is an integer of 0 or 1.]

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

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.

In the present invention, R ⁴ ″ preferably has X ³ -Q ^1- as a substituent. In this case, R ⁴ ″ may be X ³ -Q ¹ -Y ^10- [wherein Q ¹ and X ^{1 3} is the same as above, and Y ¹⁰ is an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. . ] Is preferable.
In the group represented by X ³ -Q ¹ -Y ^10- , the alkylene group for Y ¹⁰ includes the same alkylene groups as those described above for Q ¹ having 1 to 4 carbon atoms.
Examples of the fluorinated alkylene group include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^10, _{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 -, - _{CH 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 ¹⁰ 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.

Specific examples of the onium salt acid generators represented by formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenyl sulphonium trifluoromethane sulphonate, its heptafluoropropane sulphonate or its nonafluorobutane sulphonate; 1-phenyltetrahydrothiophenium trifluoromethane sulphonate, its heptafluoropropane sulphonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.
In addition, the anion part of these onium salts is an alkyl sulfonate such as methanesulfonate, n-propanesulfonate, n-butanesulfonate, n-octanesulfonate, 1-adamantanesulfonate, 2-norbornanesulfonate, d-camphor-10-sulfonate, An onium salt substituted with an aromatic sulfonate such as benzene sulfonate, perfluorobenzene sulfonate, or p-toluene sulfonate can also be used.

  Moreover, the onium salt which replaced the anion part of these onium salts by the anion part represented by either of following formula (b1)-(b9) can also be used.

［式中、ｐは１〜３の整数であり、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 p is an integer of 1 to 3, 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 ~ R2 are each independently an integer of 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, and v0 to v6 are each Are 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 same as those mentioned as the substituent that the aliphatic hydrocarbon group may have and the substituent that the aromatic hydrocarbon group may have in X ⁰³ above. 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.

  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 following 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)).

［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

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 has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, Most preferably, it has 3 carbon atoms.
Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably Has 1 to 7 carbon atoms, more preferably 1 to 3 carbon atoms.
The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Y ″ and Z ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, as the number of hydrogen atoms substituted with fluorine atoms increases, the strength of the acid 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 proportion of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. A perfluoroalkylene group or a perfluoroalkyl group.

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). The anion part represented by the general formula (b-3) or (b-4) and the like.

  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 with radiation. is there. 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 Nthenyl 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 18] to [Chemical 19]), pamphlet of International Publication No. 04/074242, An oxime sulfonate-based acid generator disclosed in Examples 1 to 40) on pages 65 to 86 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.

(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.
When the resist composition of the present invention contains the component (B), it is preferable to use an onium salt acid generator having a fluorinated alkyl sulfonate ion as an anion as the component (B).
When the resist composition of the present invention contains the component (B), the content of the component (B) in the resist composition of the present invention is 0.5 to 50 parts by mass with respect to 100 parts by mass of the component (A). Preferably, 1-40 mass parts is more preferable. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

The resist composition of the present invention preferably further contains a nitrogen-containing organic compound component (D) (hereinafter referred to as “component (D)”) as an optional component.
The component (D) is not particularly limited as long as it acts as an acid diffusion control agent, that is, a quencher that traps the acid generated from the component (B) by exposure, and a wide variety of components have already been proposed. Therefore, any known one may be used. Of these, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred.
An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, Li isopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.

  Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, tris {2 -(1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxy Ethoxy) ethoxy} ethyl] amine, triethanolamine triacetate and the like, and triethanolamine triacetate is preferable.

Moreover, you may use an aromatic amine as (D) component.
Aromatic amines include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxy. And carbonylpyrrolidine.

(D) A component may be used independently and may be used in combination of 2 or more type.
(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 comprises, as optional components, an organic carboxylic acid, a phosphorus oxo acid, and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, and the like. At least one compound (E) selected from the group (hereinafter referred to as component (E)) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids 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.
As the component (E), salicylic acid is particularly preferable.
(E) A component may be used individually by 1 type and may use 2 or more types together.
(E) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

<(F) component>
The resist composition can contain a fluorine additive (hereinafter referred to as “component (F)”) to impart water repellency to the resist film. As the component (F), for example, a fluorine-containing polymer compound described in JP 2010-002870 A can be used.
More specifically, examples of the component (F) include a polymer having a structural unit (f1) represented by the following formula (f1-1). Examples of such a polymer include a polymer consisting of only the structural unit (f1) (homopolymer); a copolymer of the structural unit represented by the following formula (f1) and the structural unit (a1); ), A copolymer of the structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1). Here, as the structural unit (a1) copolymerized with the structural unit represented by the following formula (f1), the structural unit represented by the formula (a1-1) is preferable, and the formula (a1-1) The structural unit represented by -32) is particularly preferable.

［式中、Ｒは前記同様であり、Ｒ^５１およびＲ^５２はそれぞれ独立して水素原子、ハロゲン原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基を表し、複数のＲ^５１またはＲ^５２は同じであっても異なっていてもよい。ａ１は１〜５の整数であり、Ｒ^２”はフッ素原子を含む有機基である。］

[Wherein, R is as defined above, and R ⁵¹ and R ⁵² each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, A plurality of R ⁵¹ or R ⁵² may be the same or different. a1 is an integer of 1 to 5, and R ² ″ is an organic group containing a fluorine atom.]

In formula (f1-1), R is the same as described above. R is preferably a hydrogen atom or a methyl group.
In formula (f1-1), examples of the halogen atom for R ⁵¹ and R ⁵² include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. The alkyl group of 1 to 5 carbon atoms for R ^51, R ^52, the same alkyl group of 1 to 5 carbon atoms in the R, and a methyl group or an ethyl group is preferred. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms of R ⁵¹ and R ⁵² include a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with a halogen atom. Can be mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. The Above all ^{R 51, R 52,} a hydrogen atom, a fluorine atom, or an alkyl group of 1 to 5 carbon atoms is preferable, a hydrogen atom, a fluorine atom, a methyl group or an ethyl group, preferred.
In formula (f1-1), a1 is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

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

When the component (F) is a fluorine-containing polymer compound (polymer), the mass average molecular weight (Mw) of the component (F) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, 1000-50000 are preferable, 5000-40000 are more preferable, and 10000-30000 are the most preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) of the component (F) when the component (F) is a fluorine-containing polymer compound is not particularly limited, and is preferably 1.0 to 5.0. 0 to 3.0 are more preferable, and 1.2 to 2.5 are most preferable.
In addition, Mn shows a number average molecular weight.

Further, when the component (F) is a fluorine-containing polymer compound, for example, a monomer for deriving each structural unit is dimethyl-2,2-azobis (2-methylpropionate) (V-601), azobis. The component (F) can be obtained by polymerization by a known radical polymerization using a radical polymerization initiator such as isobutyronitrile (AIBN). In the polymerization, for example, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that —C (CF ₃ ) is terminally used. _{A 2-} OH group may be introduced. As described above, a copolymer into which a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom is introduced has reduced defects and LER (line edge roughness: uneven unevenness of line side walls). Effective for reduction.
As the monomer for deriving each structural unit, a commercially available monomer may be used, or a monomer produced by a known method may be used.

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

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

The resist composition of the present invention 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; Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ethers such as ether, monopropyl ether, monobutyl ether and other monoalkyl ethers and monophenyl ether Derivatives of polyhydric alcohols such as compounds having a combination [in these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, methyl lactate Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether , Dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. Examples of the solvent include dimethyl sulfoxide (DMSO).

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.
More specifically, 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.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
Furthermore, as the component (S), a mixed solvent of PGMEA and cyclohexanone or a mixed solvent of PGMEA, PGME and cyclohexanone is also preferable. In this case, the mixing ratio of the former is preferably PGMEA: cyclohexanone = 95-5: 10-90, and the mixing ratio of the latter is preferably PGMEA: PGME: cyclohexanone = 35-55. : 20-40: 15-35.

  (S) The usage-amount of a component is not specifically limited, It is a density | concentration which can be apply | coated to a board | substrate etc., and is suitably set according to a coating film thickness. Generally, it is used so that the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

According to the present invention, a resist composition having excellent lithography properties such as sensitivity, EL margin, LWR, and pattern shape can be obtained.
The reason why the above effect is obtained is not clear, but the polymer contained in the resist composition of the present invention has an end group (I-1) that generates an acid upon exposure. Therefore, it is considered that the sensitivity is improved by generating an acid from the terminal of the polymer in the exposed portion. In addition, the polymer has a group capable of generating an acid, thereby suppressing excessive diffusion of the generated acid as compared with the case of using only a low molecular weight acid generator such as the component (B). Therefore, it is assumed that the above effects can be obtained.

  Further, when the polymer contained in the resist composition of the present invention is a component (A1) whose solubility in a developing solution is changed by the action of an acid, a terminal group (I-1) that generates an acid upon exposure. ) Are uniformly distributed in the resist film together with the component (A1), and an acid is uniformly generated from the terminal group (I-1) in the exposed portion, whereby an acid-decomposable group in the component (A1) in the exposed portion. Is cleaved uniformly, and the above effect is considered to be obtained particularly well. In addition, since the component (A1) has a group (I-1) that generates an acid upon exposure, the acid-decomposable group and the generated acid are relatively close to each other, and a decomposition reaction due to the acid is likely to occur. Therefore, it is speculated that the above effect is particularly remarkable.

≪Resist pattern formation method≫
A resist pattern forming method according to a sixth aspect of the present invention includes a step of forming a resist film on a support using the resist composition according to the fifth aspect of the present invention, a step of exposing the resist film, And a step of developing the resist film to form a resist pattern.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the resist composition is coated on a support with a spinner or the like, and pre-baked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. Then, after selectively exposing an electron beam (EB) through a desired mask pattern by an electron beam drawing machine or the like, PEB (post-exposure heating) is 40 to 120 at a temperature of 80 to 150 ° C. Second, preferably 60-90 seconds. Next, this is developed.
In the case of an alkali development process, an alkali development treatment is performed using an alkali developer, for example, a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
In the case of a solvent development process, development processing is performed using an organic solvent. The organic solvent is not particularly limited as long as it can dissolve the component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specific examples include ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and other polar solvents, hydrocarbon solvents, and the like, with ester solvents being preferred. As the ester solvent, butyl acetate is preferred.
A rinsing treatment is preferably performed after the development treatment. In the case of an alkali development process, water rinsing using pure water is preferable. In the case of the solvent development process, it is preferable to use a rinse solution containing the organic solvent mentioned above.
Thereafter, drying is performed. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist pattern faithful to the mask 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 an organic antireflection film (organic BARC).

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

The exposure 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.
In immersion exposure, at the time of exposure, a solvent (having a refractive index larger than the refractive index of air) is formed between a lens and a resist film on the wafer, which is conventionally filled with an inert gas such as air or nitrogen. Exposure is performed in a state filled with the immersion medium.
More specifically, the immersion exposure is a solvent (immersion medium) having a refractive index larger than the refractive index of air between the resist film obtained as described above and the lowermost lens of the exposure apparatus. And in that state, exposure can be performed through a desired mask pattern (immersion exposure).
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 exposed by the immersion exposure 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 preferred, and those having a boiling point of 80 to 160 ° C are more preferred. It is preferable that the fluorinated 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 Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
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).

[Synthesis Example 1: Synthesis of Compound Anion-A]
Under a nitrogen atmosphere, ACVA (28.0 g) and Anion-a (36.8 g) were added to dichloromethane (280 g) and stirred at room temperature. Diisopropylcarbodiimide (27.8 g) was added thereto and stirred for 10 minutes. Thereafter, dimethylaminopyridine (2.44 g) was added as a catalyst and reacted at 30 ° C. for 24 hours. T-Butyl methyl ether (1400 g) was added to the suspended reaction solution and stirred for 30 minutes, and then the precipitated target product was filtered off and dried to obtain 20.8 g of Anion-A.
The obtained compound was subjected to NMR measurement, and the structure was identified from the following results.
¹ H-NMR (400 MHz, DMSO-d6): δ (ppm) = 4.61 (dt, 4H, CH2CF2), 2.40-2.65 (m, 8H, CH2CH2), 1.72 (s, 6H) , CH3), 1.66 (s, 6H, CH3).
¹⁹ F-NMR (376 MHz, DMSO-d6): δ (ppm) = − 111.4.
From the above results, it was confirmed that Anion-A had the following structure.

[Synthesis Example 2: Synthesis of Compound (IA)]
TPS-Br (10.50 g), Anion-A (8.70 g), dichloromethane (155.0 g) and pure water (78.0 g) were added to the beaker, and the mixture was stirred at room temperature for 1 hour. After liquid separation, the dichloromethane layer was repeatedly washed with pure water (78.0 g), and the organic layer was concentrated under reduced pressure to obtain 13.80 g of compound (IA) as a white solid.
The obtained compound was subjected to NMR measurement, and the structure was identified from the following results.
¹ H-NMR (400 MHz, DMSO-d6): δ (ppm) = 7.78-7.90 (m, 30H, ArH), 4.61 (dt, 4H, CH 2 CF 2), 2.40-2.65 (M, 8H, CH2CH2), 1.72 (s, 6H, CH3), 1.66 (s, 6H, CH3).
¹⁹ F-NMR (376 MHz, DMSO-d6): δ (ppm) = − 111.4.
From the above results, it was confirmed that the compound (IA) had the following structure.

[Synthesis Examples 3 to 55] Synthesis of Compounds (IB) to (I-BB) In Synthesis Example 2 described above, TPS-Br (cation) was changed to those shown in the following Tables 1 to 18 (equal molar amount). The same operation was performed except that they were synthesized by changing each. Thereby, the compounds (IB) to (I-BB) shown in Tables 1 to 18 were obtained.
Each compound was analyzed by NMR, and the results are shown in Tables 1-18.

[Polymer Synthesis Example 1] Synthesis of Polymer Compound 1 11.2 g of γ-butyrolactone was placed in a flask connected with a thermometer, a reflux tube, a stirrer, and a nitrogen introduction tube under a nitrogen atmosphere, and the internal temperature was 85 while stirring. Raised to ° C.
3.0 g (17.6 mmol) of monomer (1), 4.4 g (17.6 mmol) of monomer (2), 2.1 g (8.8 mmol) of monomer (3) and 50.0 g of γ-butyrolactone Dissolved in. To this solution, 0.71 g of the compound (IA) as a radical polymerization initiator was added and dissolved.
This mixed solution was dropped into the flask at a constant rate over 4 hours, and then heated and stirred for 1 hour to cool the reaction solution to room temperature.
The obtained reaction polymerization solution was dropped into a large amount of methanol / water mixed solution to precipitate a polymer, and the precipitated white powder was filtered, washed with a methanol / water mixed solution, and then dried under reduced pressure. As a result, 6.5 g of the target polymer compound 1 was obtained.
The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement for this polymer compound was 10,150, and the molecular weight dispersity (Mw / Mn) was 1.78.
Moreover, the composition ratio (ratio (molar ratio) of each structural unit in the structural formula) of the copolymer determined by ¹³ C-NMR was 1 / m / n = 36/40/24.

[Polymer Synthesis Examples 2 to 38] Synthesis of Polymer Compounds 2 to 38 Polymer compounds 2 to 38 are represented by the following monomers (1) to (17) that derive structural units constituting each polymer compound. The polymer was produced in the same manner as in Polymer Synthesis Example 1 except that the radical polymerization initiator shown in Tables 19 to 22 was used in an equimolar amount with Polymer Synthesis Example 1. The structures of radical polymerization initiators V-601 and ACVA are as shown in the following formula.
The mass average molecular weight (Mw) and the molecular weight dispersion (Mw / Mn) of the obtained polymer compounds 2 to 38 are also shown in Tables 19 to 22.

[Examples 1 to 28, Comparative Examples 1 to 17]
Each component shown in Tables 23 to 25 was mixed and dissolved to prepare a positive resist composition.

Each abbreviation in Tables 23 to 25 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1 to (A) -38: The above polymer compounds 1 to 38.
(B) -1: The following compound (B) -1.
(B) -2: The following compound (B) -2.
(D) -1: tri-n-octylamine.
(E) -1: salicylic acid.
(F) -1: the following polymer compound (F) -1 [l / m = 77/23 (molar ratio), Mw = 23000, Mw / Mn = 1.61, radical polymerization with radical polymerization initiator V-601 A polymer produced by ].
(F) -2: produced by radical polymerization with the following polymer compound (F) -2 [l = 100 (molar ratio), Mw = 22000, Mw / Mn = 1.58, radical polymerization initiator V-601. Polymer. ].
(S) -1: PGMEA / PGME / cyclohexanone = 45/30/25 (mass ratio) mixed solvent.

[Formation of resist pattern 1]
An organic antireflection film composition “ARC95” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto a 12-inch silicon wafer using a spinner, and baked at 205 ° C. for 90 seconds on a hot plate and dried. Thereby, an organic antireflection film having a thickness of 90 nm was formed.
Then, the positive resist composition of each example is applied onto the organic antireflection film using a spinner, and prebaked (PAB) on the hot plate at the temperatures shown in Tables 26 to 27 for 60 seconds. By performing the treatment and drying, a resist film having a thickness of 100 nm was formed.
Next, an ArF excimer laser was used with an ArF immersion exposure apparatus NSR-S609B (manufactured by Nikon Corporation; NA (numerical aperture) = 1.07, Dipole (in / out: 0.78 / 0.97), w / POLANO). (193 nm) was selectively irradiated through the mask pattern.
And the PEB process for 60 second was performed at the temperature shown to Tables 26-27, and also 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (brand name, Tokyo Ohka Kogyo Co., Ltd.) at 23 degreeC. Manufactured for 10 seconds, rinsed with pure water for 15 seconds, and shaken and dried.
Subsequently, post-baking was performed on a hot plate at 100 ° C. for 45 seconds.
As a result, in all examples except Comparative Example 16, a 1: 1 line and space (LS) pattern having a line width of 50 nm and a pitch of 100 nm was formed (Comparative Example 16 had no pattern formed).
The optimum exposure dose Eop (mJ / cm ² ; sensitivity) for forming the LS pattern was determined. The results are also shown in Tables 26-27.

[Evaluation of exposure margin (EL margin)]
In Eop, the exposure amount when the line of the LS pattern is formed within a range of ± 5% (47.5 nm to 52.5 nm) of the target dimension (line width 50 nm) is obtained, and the EL margin (unit: %). The results are shown in Tables 26-27.
EL margin (%) = (| E1-E2 | / EOP) × 100
E1: Exposure amount (mJ / cm ² ) when an LS pattern having a line width of 47.5 nm was formed
E2: exposure amount (mJ / cm ² ) when an LS pattern having a line width of 52.5 nm was formed
Note that the larger the value of the EL margin, the smaller the change amount of the pattern size accompanying the change in the exposure amount.

[Evaluation of mask error factor (MEF)]
According to the same procedure as the formation of the resist pattern, in the Eop, a mask pattern targeting a LS pattern with a line width of 50 nm and a pitch of 100 nm and a mask pattern targeting a LS pattern with a line width of 55 nm and a pitch of 100 nm are used. Each LS pattern was formed, and the MEF value was determined from the following equation. The results are shown in Tables 26-27.
MEF = | CD55-CD50 | / | MD55-MD50 |
In the above formula, CD50 and CD55 are the actual line widths (nm) of the LS pattern formed using the mask pattern targeting the line widths of 50 nm and 55 m, respectively. MD50 and MD55 are line widths (nm) targeted by the mask pattern, respectively, and MD50 = 50 nm and MD55 = 55 nm.
The closer this MEF value is to 1, the more the resist pattern faithful to the mask pattern is formed.

[LWR (line width roughness) evaluation]
In the LS pattern having a line width of 50 nm and a pitch of 100 nm formed by the Eop, the space width is changed by a length measuring SEM (scanning electron microscope, acceleration voltage 300 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). 400 points were measured in the longitudinal direction, and a triple value (3s) of the standard deviation (s) was obtained from the result, and a value averaged for 3s at 400 points was calculated as a scale indicating LWR. The results are shown in Tables 26-27.
A smaller value of 3s means that the roughness of the line width is smaller, and an LS pattern having a more uniform width is obtained.

[Pattern shape evaluation]
The cross-sectional shape of the pattern formed in the Eop was observed using a scanning electron microscope (trade name: SU-8000, manufactured by Hitachi High-Technology Corporation), and the shape was evaluated according to the following criteria. The results are shown in Tables 26 to 27.
○: The rectangularity is high and good.
Δ: Slightly T-top shape.

  From the results of Tables 26 to 27, the resist compositions of Examples 1 to 28 according to the present invention have higher sensitivity than the resist compositions of Comparative Examples 1 to 17, and EL margin, MEF, LWR, etc. It was confirmed that the lithographic characteristics and pattern shape were excellent.

[Example 29, Comparative Examples 18 to 19]
Each component shown in Table 28 was mixed and dissolved to prepare a positive resist composition.

  In each abbreviation in Table 28, (A) -1, (A) -24, (A) -25, (D) -1, (E) -1 and (S) -1 are the same as above, B) -3 means the following compound (B) -3. Moreover, the numerical value in [] is a compounding quantity (mass part).

[Formation of resist pattern 2]
The positive resist composition of each example was applied onto an 8-inch silicon wafer that had been subjected to hexamethyldisilazane (HMDS) treatment at 90 ° C. for 36 seconds using a spinner. A resist film having a film thickness of 60 nm was formed by performing pre-baking (PAB) treatment at the temperature shown in FIG.
Next, the resist film is exposed using an electron beam lithography machine HL-800D (VSB) (manufactured by Hitachi) at an acceleration voltage of 70 kV, and subjected to PEB treatment at a temperature shown in Table 29 for 60 seconds. At 23 ° C., alkali development was performed for 60 seconds using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.), and 15% using pure water. Water rinsing was performed for 2 seconds, followed by shaking off and drying.
Subsequently, post-baking was performed on a hot plate at 100 ° C. for 60 seconds.
As a result, in each example, a 1: 1 LS pattern having a line width of 100 nm and a pitch of 200 nm was formed.
The optimum exposure dose Eop (μC / cm ² ; sensitivity) for forming the LS pattern was determined, and the EL margin (10%), LWR, and shape in the Eop were evaluated in the same manner as described above. The results are shown in Table 29.

  From the results of Table 29, the resist composition of Example 29 according to the present invention has higher sensitivity than the resist compositions of Comparative Examples 18 to 19, and has lithography characteristics such as EL margin and LER, and pattern shape. It was confirmed that it was excellent.

Claims (10)

The compound represented by the following general formula (I).

[Wherein, R ¹ is a hydrocarbon group having 1 to 10 carbon atoms, and Z is a cyano group. X is a divalent linking group, and at least one of —O—C (═O) —, —NH—C (═O) —, and —NH—C (═NH) — It is at the end that contacts Q. p is an integer of 1 to 3. Q is a (p + 1) -valent hydrocarbon group, and Q may be a single bond only when p is 1. R ² is a single bond, an alkylene group which may have a substituent, or an aromatic group which may have a substituent, q and r are each independently 0 or 1, and A ⁺ is It is a metal cation or an organic cation. A plurality of R ¹ , Z, X, p, Q, R ² , q, r, and A ⁺ in the formula may be the same or different. ]   A radical polymerization initiator comprising the compound according to claim 1. It is a manufacturing method of the compound of Claim 1, Comprising:
The manufacturing method including the process with which the compound represented with the following general formula (i-1) and the compound represented with the following general formula (i-2) are made to react.

[Wherein, R ¹ , Z, X, Q, p, q, R ² , r, and A ⁺ are the same as defined above, and B ¹ and B ² are each independently H or OH. A plurality of R ¹ , Z, X, p, Q, and B ¹ in the formula may be the same or different. ] A polymer having a group represented by the following general formula (I-1) at at least one end of the main chain.

[Wherein, R ¹ is a hydrocarbon group having 1 to 10 carbon atoms, and Z is a cyano group. X is a divalent linking group, and at least one of —O—C (═O) —, —NH—C (═O) —, and —NH—C (═NH) — It is at the end that contacts Q. p is an integer of 1 to 3. Q is a (p + 1) -valent hydrocarbon group, and Q may be a single bond only when p is 1. R ² is a single bond, an optionally substituted alkylene group, or an optionally substituted aromatic group, q and r are each independently 0 or 1, and M ⁺ is Organic cation. ] A resist composition containing the polymer according to claim 4 . The resist composition according to claim 5 , wherein the solubility of the polymer in a developer is changed by the action of an acid. A resist composition containing a base material component (A) that changes the solubility in a developer by the action of an acid and generates an acid upon exposure, and an acid generator component (B) that generates an acid upon exposure,
The resist composition in which the base material component (A) contains the polymer according to claim 4 . The resist composition according to claim 7 , wherein the polymer increases in polarity by the action of an acid. The resist composition according to claim 8 , wherein the polymer has a structural unit (a1) derived from an acrylate ester containing an acid-decomposable group whose polarity is increased by the action of an acid. A step of forming a resist film on a support using the resist composition according to any one of claims 5 to 9 , a step of exposing the resist film, and developing the resist film to form a resist pattern A resist pattern forming method including the step of: