JP6118576B2 - Resist composition, resist pattern formation method, compound, radical polymerization initiator, compound production method, polymer - Google Patents

Description

  The present invention relates to a compound useful as a radical polymerization initiator, a radical polymerization initiator comprising the compound, a method for producing the compound, a polymer useful for a resist composition produced using the radical polymerization initiator, The present invention relates to a resist composition containing a 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. It has been.
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, and acid generation. The agent component is generally used. When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the acid generator component in the exposed portion, and the alkali developer of the resin component is generated by the action of the acid. As a result, the exposed area becomes soluble in an alkaline developer. 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. When a process using an organic solvent-containing developer (organic developer) (hereinafter sometimes referred to as a solvent development process or a negative development process) is applied instead of an alkali development process, Solubility in organic developers is reduced. Therefore, in the solvent development process, the unexposed portion of the resist film is dissolved and removed by the organic developer, and a negative resist pattern in which the exposed portion remains as a pattern is formed.

  At present, 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. Resin) is generally used (see, for example, Patent Document 1).

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. Then, the polymer is synthesized by the addition polymerization of the monomers by the action of the radical. 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 the polymerization initiator introduced at the end of the main chain of the polymer, the polymerization initiator having an acetal type acid dissociable, dissolution inhibiting group as the partial structure, and the polymerization initiator as the base resin A polymer obtained by use is disclosed (see Patent Document 2).
Further, a resin in which a group having absorption at 248 nm as the partial structure is introduced at the end of the main chain of the polymer is disclosed (see Patent Document 3).

JP 2003-241385 A JP 2007-308586 A JP 2008-268875 A

With further advancement of lithography technology and expansion of application fields, there is a demand for new materials that can be used for lithography applications. For example, as pattern miniaturization progresses, the resist material can be a hole pattern such as roughness (LWR (line width roughness: line width non-uniformity) for line patterns) as well as sensitivity and resolution. Further improvement of various lithography properties and pattern shapes such as roundness, mask reproducibility, and exposure margin is required.
However, the resist material using the base resin described in Patent Document 2 cannot sufficiently satisfy the required lithography characteristics and pattern shape. Moreover, when synthesizing the resin described in Patent Document 3, complicated operations are involved. In the case of ArF excimer laser lithography, absorption is a problem.
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 polymer useful for the resist composition, and simple production for obtaining the polymer It is an object to provide a method.

The present inventors can solve the above-mentioned problems by using a polymerization initiator having a tertiary ester type acid dissociable group (excluding a tert-butyl group) as a partial structure introduced at the polymer terminal. As a result, the present invention has been completed.
That is, the first aspect of the present invention is a resist composition that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid. The material component (A) is contained, and the base material component (A) contains a polymer having a group represented by the following general formula (I-1) at at least one end of the main chain. The resist composition.

［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は単結合、又は−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−若しくは−ＮＨ−Ｃ（＝ＮＨ）−を含んでいてもよい２価の連結基である。Ｒ^２は炭素数４〜２０の第３級エステル型酸解離性基（ただし、ｔｅｒｔ−ブチル基を除く）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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). ]

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

  A third 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は単結合、又は−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−若しくは−ＮＨ−Ｃ（＝ＮＨ）−を含んでいてもよい２価の連結基である。Ｒ^２は炭素数４〜２０の第３級エステル型酸解離性基（ただし、ｔｅｒｔ−ブチル基を除く）である。式中の複数のＲ^１、Ｚ、Ｘ及びＲ^２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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). A plurality of R ¹ , Z, X and R ² in the formula may be the same or different. ]

The fourth aspect of the present invention is a radical polymerization initiator comprising the compound of the third aspect.
A fifth aspect of the present invention is a method for producing the compound of the third aspect, which is represented by a compound represented by the following general formula (i-1) and the following general formula (i-2). It is a manufacturing method of a compound including the process with which a compound is made to react.

［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は単結合、又は−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−若しくは−ＮＨ−Ｃ（＝ＮＨ）−を含んでいてもよい２価の連結基である。Ｒ^２は炭素数４〜２０の第３級エステル型酸解離性基（ただし、ｔｅｒｔ−ブチル基を除く）である。式中の複数のＲ^１、Ｚ及びＸ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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). A plurality of R ¹ , Z and X in the formula may be the same or different. ]

  The sixth 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は単結合、又は−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−若しくは−ＮＨ−Ｃ（＝ＮＨ）−を含んでいてもよい２価の連結基である。Ｒ^２は炭素数４〜２０の第３級エステル型酸解離性基（ただし、ｔｅｒｔ−ブチル基を除く）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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). ]

  According to the present invention, it is possible to provide a resist composition excellent in lithography characteristics and pattern shape, a polymer useful for the resist composition, and a simple production method for obtaining the polymer.

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 same applies to the alkyl group in the alkoxy group.
The “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
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).
When it is described as “may have a substituent”, when a hydrogen atom (—H) is substituted with a monovalent group, and when a methylene group (—CH ₂ —) is substituted with a divalent group And both.
“Exposure” is a concept including general irradiation of radiation.

“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid ester” is a compound in which the hydrogen atom at the carboxy group terminal of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
In the acrylate ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent (R ^α0 ) for substituting the hydrogen atom bonded to the α-position carbon atom is an atom or group other than a hydrogen atom, such as an alkyl group having 1 to 5 carbon atoms or a halogenated group having 1 to 5 carbon atoms. An alkyl group etc. are mentioned. In addition, itaconic acid diesters in which the substituent (R ^α0 ) is substituted with a substituent containing an ester bond, and α-hydroxyacrylic esters in which the substituent (R ^α0 ) is substituted with a hydroxyalkyl group or a group with a modified hydroxyl group thereof Shall be included. The α-position carbon atom of the acrylate ester is a carbon atom to which the carbonyl group of acrylic acid is bonded unless otherwise specified.
Hereinafter, an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylate ester. Further, the acrylate ester and the α-substituted acrylate ester may be collectively referred to as “(α-substituted) acrylate ester”.

“Structural unit derived from acrylamide” means a structural unit formed by cleavage of the ethylenic double bond of acrylamide.
In acrylamide, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and one or both of the hydrogen atoms of the amino group of acrylamide may be substituted with a substituent. The α-position carbon atom of acrylamide is a carbon atom to which the carbonyl group of acrylamide is bonded unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom bonded to the α-position carbon atom of acrylamide are the same as those described as the α-position substituent (substituent (R ^α0 )) in the α-substituted acrylic ester. Can be mentioned.

“A structural unit derived from hydroxystyrene or a hydroxystyrene derivative” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene or a hydroxystyrene derivative.
“Hydroxystyrene derivative” is a concept including those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. These derivatives include those obtained by substituting the hydrogen atom of the hydroxyl group of hydroxystyrene which may be substituted with a hydrogen atom at the α-position with an organic group; The thing etc. which the substituents other than a hydroxyl group couple | bonded with the benzene ring of good hydroxystyrene are mentioned. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same substituents as those mentioned as the substituent at the α-position in the α-substituted acrylic ester.

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

“Styrene” is a concept that includes styrene and those in which the α-position hydrogen atom of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group.
“Structural unit derived from styrene” and “structural unit derived from styrene derivative” mean a structural unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.

The alkyl group as a substituent at the α-position is preferably a linear or branched alkyl group, specifically, an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group). , N-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like.
Specific examples of the halogenated alkyl group as the substituent at the α-position include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α-position” are substituted with a halogen atom. It is done. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
Specific examples of the hydroxyalkyl group as a substituent at the α-position include a group in which part or all of the hydrogen atoms of the “alkyl group as the substituent at the α-position” are substituted with a hydroxyl group. 1-5 are preferable and, as for the number of the hydroxyl groups in this hydroxyalkyl group, 1 is the most preferable.

≪Resist composition≫
A first aspect of the present invention is a resist composition that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid, and is a base material component whose solubility in the developer changes due to the action of an acid (A) (hereinafter also referred to as “component (A)”).
When a resist film is formed using such a resist composition and the resist film is selectively exposed, an acid is generated in the exposed portion, and the action of the acid causes the solubility of the component (A) in the developer. On the other hand, since the solubility of the component (A) in the developer does not change in the unexposed area, a difference in solubility in the developer occurs between the exposed and unexposed areas. Therefore, when the resist film is developed, when the resist composition is positive, the exposed portion is dissolved and removed to form a positive resist pattern, and when the resist composition is negative, the unexposed portion is dissolved. This is removed to form a negative resist pattern.
In this specification, a resist composition in which an exposed portion is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and an unexposed portion is dissolved and removed to form a negative resist pattern. Is referred to as a negative resist composition.
The resist composition of this embodiment may be a positive resist composition or a negative resist composition.
Further, the resist composition of this embodiment may be used for an alkali development process using an alkali developer for the development process at the time of forming a resist pattern, and a developer (organic developer) containing an organic solvent is used for the development process. It may be for the solvent development process used.

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

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

The component (A) used in the resist composition of this embodiment is a polymer having a group represented by the general formula (I-1) at at least one end of the main chain (hereinafter referred to as “(A1) component”). ").
As the component (A), at least the component (A1) is used, and another polymer and / or a low molecular compound may be used in combination with the component (A1).
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 proportion is 25% by mass or more, good lithography characteristics and a resist pattern shape are easily obtained.
Component (A) may have increased solubility in a developer due to the action of an acid, or may decrease solubility in a developer due to the action of an acid.

[(A1) component]
The component (A1) is a polymer having a group represented by the following general formula (I-1) (hereinafter also referred to as “terminal group (I-1)”) at at least one end of the main chain.
The terminal group (I-1) has a tertiary ester type acid dissociable group (excluding a tert-butyl group) that can be dissociated by the action of an acid. By having the terminal group (I-1), the component (A1) is dissociated from the tertiary ester type acid dissociable group “R ² ” in the terminal group (I-1) by the action of an acid, A carboxy group is formed at the end of the polymer to increase the polarity. For this reason, when the component (A1) is used in the resist composition, the solubility of the resist film in the developer changes in forming the resist pattern. That is, the solubility in an alkali developer increases (becomes positive in the alkali development process), and the solubility decreases in an organic solvent-containing developer (organic developer) (in the solvent development process). Negative).
That is, when an alkali development process is applied, the component (A1) is hardly soluble in an alkali developer before exposure, and when an acid is generated by exposure, the polarity increases due to the action of the acid, and the alkali developer Increased solubility in 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 resist pattern can be formed by alkali development.
On the other hand, when the solvent development process is applied, the component (A1) is highly soluble in an organic developer before exposure. When an acid is generated by exposure, the polarity of the component increases due to the action of the acid. Solubility in developer is reduced. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the resist composition on the support is selectively exposed, the exposed portion changes from soluble to poorly soluble in an organic developer. On the other hand, since the unexposed portion remains soluble and does not change, by developing with an organic developer, a contrast can be provided between the exposed portion and the unexposed portion, and a negative resist pattern can be formed.

［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は単結合、又は−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−若しくは−ＮＨ−Ｃ（＝ＮＨ）−を含んでいてもよい２価の連結基である。Ｒ^２は炭素数４〜２０の第３級エステル型酸解離性基（ただし、ｔｅｒｔ−ブチル基を除く）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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). ]

End group (I-1):
In the formula (I-1), the hydrocarbon group having 1 to 10 carbon atoms in R ¹ may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, An aliphatic hydrocarbon group is preferable, and a monovalent aliphatic saturated hydrocarbon group (alkyl group) is more preferable.
More specifically, examples of the alkyl group include a chain aliphatic hydrocarbon group (a linear or branched alkyl group) and an aliphatic hydrocarbon group having a ring in the structure.
The linear alkyl group preferably has 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, and 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. Examples thereof include a group bonded to the terminal of a chain-like aliphatic hydrocarbon group or a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of the chain-like aliphatic hydrocarbon group described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 8 carbon atoms, 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 have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, and an oxygen atom (= O).

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

In the formula (I-1), R ¹ and Z may be bonded to each other to form a ring. Specifically, R ¹ and Z are each independently a linear or branched alkyl group, and the end of R ^{1 and} the end of Z are bonded to each other to form a ring. Also good. The ring formed by R ¹ , Z and the carbon atom to which R ¹ and Z are bonded together is preferably a ring having 3 to 8 carbon atoms, more preferably cyclopentane, cyclohexane, cycloheptane or cyclooctane, Cyclohexane is particularly preferred.

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, and a combination of an ethyl group and a cyano group; and R ¹ binds to a, and Z, groups obtained by removing two hydrogen atoms from cyclohexane formed by the carbon atoms R ¹ and Z are bonded together are preferable, R ¹ among them is a methyl group, It is particularly preferred that Z is a cyano group.

In the formula (I-1), X may include a single bond, or —O—C (═O) —, —NH—C (═O) —, or —NH—C (═NH) —. It is a good divalent linking group.
X is a single bond, a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom; -O-C (= O)-, -NH-C (= O)-or -NH-C (= NH)-and a combination of a divalent hydrocarbon group which may have a substituent; -O-C (= O)-,- Composed of a combination of either NH—C (═O) — or —NH—C (═NH) — and a divalent linking group containing a hetero atom; —O—C (═O) —, — NH-C (= O)-, -NH-C (= NH)-and the like can be mentioned.

Divalent hydrocarbon group which may have a substituent:
In the present invention, “the hydrocarbon group has a 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.

As the aliphatic hydrocarbon group in the divalent hydrocarbon group, more specifically, a chain aliphatic hydrocarbon group (a linear or branched aliphatic hydrocarbon group), a ring in the structure And an aliphatic hydrocarbon group containing.
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 in which the cyclic aliphatic hydrocarbon group is interposed in the middle of the chain aliphatic hydrocarbon group, or the like.
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. The monocyclic 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 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).

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

A divalent linking group containing a heteroatom:
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 the same as those described above (the divalent hydrocarbon group which may have a substituent). An aliphatic hydrocarbon group containing a ring in the chain or structure 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. The aliphatic hydrocarbon group and aromatic hydrocarbon group in A are the aliphatic hydrocarbon group and aromatic hydrocarbon group in the description of the above (divalent hydrocarbon group which may have a substituent). It is the same. Among them, A is preferably an aliphatic hydrocarbon group. 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. 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 more 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 an aliphatic hydrocarbon group, more preferably a linear or branched aliphatic hydrocarbon group, and 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 consists only of -O-C (= O)-, -NH-C (= O)-or -NH-C (= NH)-, X is -O-C (= O )-Or -NH-C (= O)-. 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 to which R ¹ and Z are bonded. Bonding is preferred.
X is any of —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) — as described above, and a divalent group (having a substituent). X is —O—C (═O) — or —NH—C (═O) in the case of a combination with a divalent hydrocarbon group, which may be a divalent linking group containing a hetero atom). A combination of any one of-or -NH-C (= NH)-and a divalent hydrocarbon group which may have a substituent is preferable; -O-C (= O)-,- More preferred is a combination of either NH—C (═O) — or —NH—C (═NH) — and a linear or branched aliphatic hydrocarbon group having 1 to 5 carbon atoms. A combination of either —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) — with a methylene group or an ethylene group; More preferably in at allowed, ethylene group and -NH-C (= NH) - it is particularly preferably a combination of.

  Among the above, X may be any of —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —, and may have a substituent. A combination with a good divalent hydrocarbon group, a divalent hydrocarbon group which may have a substituent, a single bond is particularly preferred, and a divalent hydrocarbon which may have a substituent The group is most preferred. Among them, an aliphatic hydrocarbon group is more preferable, a chain aliphatic hydrocarbon group (a linear or branched aliphatic hydrocarbon group) is more preferable, and a linear aliphatic hydrocarbon group is more preferable. Particularly preferred.

In the formula (I-1), ^{R 2} is a tertiary ester-type acid dissociable group having 4 to 20 carbon atoms (excluding tert- butyl group).
In the present invention, the “tertiary ester type acid dissociable group” has a tertiary carbon atom and forms an ester structure with —C (═O) —O— in the general formula (I-1). A group that is capable of cleaving a bond between the tertiary carbon atom and an adjacent oxygen atom (—O—) by the action of an acid;
Examples of R ² include a group that forms a chain or cyclic tertiary ester with a carboxy group.
The “tertiary ester” is, for example, an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic group, and the carbonyloxy group (—C (═O) —O A structure in which a tertiary carbon atom of a chain or cyclic group is bonded to the oxygen atom (-O-) at the terminal of-). In this tertiary ester, when an acid acts, a bond is cleaved between an oxygen atom (—O—) and a tertiary carbon atom to form a carboxy group. In the terminal group (I-1), the tertiary ester type acid dissociable group “R ² ” is dissociated by the action of an acid to form a carboxy group.
When R ² is a chain-like tertiary ester-type acid dissociable group, the carbon number of R ² is 5 or more, preferably 5 to 10.
When R ² is a tertiary ester-type acid dissociable group containing a ring in the structure, R ² has 4 to 20 carbon atoms, preferably 7 to 20 carbon atoms.

Preferred examples of the tertiary ester type acid dissociable group “R ² ” include acid dissociable groups represented by general formula (a1-r-2) shown below.

［式中、Ｒａ’^４〜Ｒａ’^６はそれぞれ置換基を有していてもよい炭化水素基であって、Ｒａ’^５とＲａ’^６とは互いに結合して環を形成してもよい（ただし、全部がメチル基となる場合を除く）。］

[Wherein, Ra ′ ^{4 to} Ra ′ ⁶ are each a hydrocarbon group which may have a substituent, and Ra ′ ⁵ and Ra ′ ⁶ may be bonded to each other to form a ring ( However, unless all are methyl groups). ]

In the formula (a1-r-2), examples of the hydrocarbon group of Ra ′ ^{4 to} Ra ′ ⁶ include a linear or branched alkyl group and a cyclic hydrocarbon group.
The linear alkyl group in Ra ′ ^{4 to} Ra ′ ⁶ 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, and an n-butyl group are preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group in Ra ′ ^{4 to} Ra ′ ⁶ 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, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, and the like is preferably isopropyl group.
However, Ra ′ ⁵ and Ra ′ ⁶ may be bonded to each other to form a ring.

The cyclic hydrocarbon group in Ra ′ ^{4 to} Ra ′ ⁶ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically, Adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
In the case of an aromatic hydrocarbon group, specific examples of the aromatic ring included include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; some of the carbon atoms constituting the aromatic hydrocarbon ring are heterogeneous. Aromatic heterocycles substituted with atoms and the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); an aromatic compound containing two or more aromatic rings A group obtained by removing one hydrogen atom from (for example, biphenyl, fluorene, etc.); 1 of the hydrogen atoms of a group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring Groups substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group) and the like. .
The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

The hydrocarbon group in Ra ′ ^{4 to} Ra ′ ⁶ may have a substituent.
“The hydrocarbon group may have a substituent” means that part or all of the hydrogen atoms in the hydrocarbon group may be substituted with a substituent.
R ² has 4 to 20 carbon atoms, and this 4 to 20 carbon atoms includes a carbon atom in the substituent.
As the substituent here, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc .; preferably a fluorine atom), a halogenated alkyl group (preferably a fluorinated alkyl group), an oxygen atom (═O), cyano group _{(-CN), - CO 2 OCH} 3, -NO 2 , and the like. Specifically, as the halogenated alkyl group, part or all of the hydrogen atoms of the “alkyl group (preferably an alkyl group having 1 to 5 carbon atoms)” are halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.) Group preferably substituted with a fluorine atom).
However, in the hydrocarbon group in Ra ′ ^{4 to} Ra ′ ⁶ , a part of the carbon atoms constituting the hydrocarbon group may be substituted with atoms or atomic groups other than carbon atoms. Examples of atoms other than carbon atoms include heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and silicon atoms.

In the formula (a1-r-2), Ra ′ ⁴ is preferably an alkyl group having 1 to 5 carbon atoms out of Ra ′ ^{4 to} Ra ′ ⁶ .
When Ra ′ ⁵ and Ra ′ ⁶ are bonded to each other to form a ring, for example, a group represented by the following general formula (a1-r2-1) can be mentioned.
On the other hand, when Ra ′ ^{4 to} Ra ′ ⁶ are not bonded to each other and each is an independent hydrocarbon group, a group represented by the following general formula (a1-r2-2) is exemplified.

［式中、Ｒａ’^１０は炭素数１〜１０のアルキル基である。Ｒａ’^１１はＲａ’^１０が結合した炭素原子と共に脂肪族環式基を形成する基である。Ｒａ’^１２〜Ｒａ’^１４は、それぞれ独立に炭化水素基を示す（ただし、全部がメチル基となる場合を除く）。］

[In the formula, Ra ′ ¹⁰ is an alkyl group having 1 to ¹⁰ carbon atoms. Ra ′ ¹¹ is a group that forms an aliphatic cyclic group together with the carbon atom to which Ra ′ ¹⁰ is bonded. Ra ′ ^{12 to} Ra ′ ¹⁴ each independently represent a hydrocarbon group (except when all are methyl groups). ]

In the formula (a1-r2-1), the alkyl group having 1 to ¹⁰ carbon atoms in Ra ′ ¹⁰ is preferably a group exemplified as the linear or branched alkyl group in Ra ′ ^{4 to} Ra ′ ⁶ . . In formula (a1-r2-1), the aliphatic cyclic group formed by Ra ′ ¹¹ together with the carbon atom to which Ra ′ ¹⁰ is bonded is the group exemplified as the cyclic hydrocarbon group in Ra ′ ^{4 to} Ra ′ ⁶ . Are preferable, and a monocyclic alicyclic hydrocarbon group is more preferable.

In the formula (a1-r2-2), Ra ′ ¹² and Ra ′ ¹⁴ are preferably each independently an alkyl group having 1 to 10 carbon atoms, and the alkyl group is the Ra ′ ^{4 to} Ra ′ ^6. Are more preferably a linear alkyl group having 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group.
In formula (a1-r2-2), Ra ′ ¹³ represents a linear or branched alkyl group in the above Ra ′ ^{4 to} Ra ′ ⁶ , or a monocyclic alicyclic hydrocarbon group or polycyclic ring An alicyclic hydrocarbon group of the formula is preferred. Among these, Ra ′ ¹³ is more preferably a group exemplified as a monocyclic alicyclic hydrocarbon group or a polycyclic alicyclic hydrocarbon group.

  Specific examples of the group represented by the formula (a1-r2-1) are given below. In addition, in this specification, * mark in a formula shows a bond (bonding position with oxygen atom -O-).

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

Among these, as the tertiary ester-type acid dissociable group for R ² , a group represented by the general formula (a1-r2-1) is preferable, and Ra ′ in the formula (a1-r2-1) is preferred. More preferably, the aliphatic cyclic group formed by ¹¹ together with the carbon atom to which Ra ′ ¹⁰ is bonded is a monocyclic alicyclic hydrocarbon group.

The component (A1) may be any component having the terminal group (I-1) represented by the general formula (I-1) at least at one terminal of the main chain. About the structure other than ()), the structure similar to the resin component (base resin) currently normally used as a base-material component for chemically amplified resists is employable.
As the component (A1), those having a structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid are preferable.
In addition to the structural unit (a1), the component (A1) further includes a structural unit (a2) (structural unit (a) containing a lactone-containing cyclic group, an —SO ₂ -containing cyclic group, or a carbonate-containing cyclic group. Those having (except for those corresponding to a1)) are preferred.
In addition to the structural unit (a1) or in addition to the structural units (a1) and (a2), the component (A1) further includes a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group ( Those having a structural unit (a1) or a structural unit (a2) are preferred).
Especially, as for (A1) component, what has the structural unit induced | guided | derived from the acrylate ester in which the hydrogen atom couple | bonded with the carbon atom of alpha-position may be substituted by the substituent is especially preferable.

(Structural unit (a1))
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid.
The “acid-decomposable group” is an acid-decomposable group that can cleave at least part of bonds in the structure of the acid-decomposable group by the action of an acid.
Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (—SO ₃ H), and the like. Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is more preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).
Here, the “acid-dissociable group” means (i) a group having acid-dissociable properties capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid, Alternatively, (ii) after a partial bond is cleaved by the action of an acid, a further decarboxylation reaction occurs, whereby a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group is cleaved. Both of the resulting groups.
The acid-dissociable group constituting the acid-decomposable group must be a group having a lower polarity than the polar group generated by dissociation of the acid-dissociable group. Is dissociated, a polar group having a polarity higher than that of the acid dissociable group is generated to increase the polarity. As a result, the polarity of the entire component (A1) increases. As the polarity increases, the solubility in the developer changes relatively. When the developer is an alkaline developer, the solubility increases. When the developer is an organic developer, the solubility increases. Decrease.

The acid-dissociable group is not particularly limited, and those that have been proposed as acid-dissociable groups for base resins for chemically amplified resists can be used.
Examples of the acid dissociable group that protects a carboxy group or a hydroxyl group among the polar groups include, for example, an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter referred to as “acetal acid dissociable group”). May be included).

［式中、Ｒａ’^１、Ｒａ’^２は水素原子またはアルキル基であり、Ｒａ’^３は炭化水素基であって、Ｒａ’^３は、Ｒａ’^１、Ｒａ’^２のいずれかと結合して環を形成してもよい。］

[Wherein, Ra ′ ¹ and Ra ′ ² are a hydrogen atom or an alkyl group, Ra ′ ³ is a hydrocarbon group, and Ra ′ ³ is bonded to either Ra ′ ¹ or Ra ′ ² to form a ring. May be formed. ]

In formula (a1-r-1), at least one of Ra ′ ¹ and Ra ′ ² is preferably a hydrogen atom, and more preferably both are hydrogen atoms.
In the case where Ra ′ ¹ or Ra ′ ² is an alkyl group, the alkyl group is the alkyl group mentioned as the substituent that may be bonded to the α-position carbon atom in the description of the α-substituted acrylate ester. The same thing is mentioned, A C1-C5 alkyl group is preferable. Specifically, a linear or branched alkyl group is preferable. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like can be given. More preferred is a methyl group.

In formula (a1-r-1), examples of the Ra ′ ³ hydrocarbon group include a linear or branched alkyl group and a cyclic hydrocarbon 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, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, and the like is preferably isopropyl group.

When Ra ′ ³ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically, Adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

When the cyclic hydrocarbon group of Ra ′ ³ is an aromatic hydrocarbon group, the aromatic ring contained is specifically an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, phenanthrene; the aromatic hydrocarbon ring An aromatic heterocyclic ring in which a part of the carbon atoms constituting is substituted with a heteroatom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); an aromatic compound containing two or more aromatic rings A group obtained by removing one hydrogen atom from (for example, biphenyl, fluorene, etc.); 1 of the hydrogen atoms of a group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring Groups substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group) and the like. .
The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

When Ra ′ ³ is bonded to either Ra ′ ¹ or Ra ′ ² to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  Moreover, as an acid dissociable group which protects a carboxy group among the said polar groups, the acid dissociable group represented by the general formula (a1-r-2) mentioned above is mentioned, for example.

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

［式中、Ｒａ’^７〜Ｒａ’^９はそれぞれアルキル基である。］

[Wherein, Ra ′ ^{7 to} Ra ′ ⁹ each represents an alkyl group. ]

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

  The structural unit (a1) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and an acid whose polarity is increased by the action of an acid. Structural unit containing a decomposable group; a structural unit derived from acrylamide and containing an acid-decomposable group whose polarity is increased by the action of an acid; a hydroxyl group of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative A structural unit in which at least a part of the hydrogen atoms in is protected by a substituent containing the acid-decomposable group; a hydrogen atom in —C (═O) —OH of a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative And a structural unit in which at least a part of the group is protected by a substituent containing the acid-decomposable group.

Among the above, the structural unit (a1) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent.
Preferable specific examples of the structural unit (a1) include structural units represented by the following general formula (a1-1) or (a1-2).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｖａ^１はエーテル結合を有していてもよい２価の炭化水素基であり、ｎ_ａ１は０〜２であり、Ｒａ^１は上記式（ａ１−ｒ−１）又は（ａ１−ｒ−２）で表される酸解離性基である。Ｗａ^１はｎ_ａ２＋１価の炭化水素基であり、ｎ_ａ２は１〜３であり、Ｒａ^２は上記式（ａ１−ｒ−１）又は（ａ１−ｒ−３）で表される酸解離性基である。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Va ¹ is a divalent hydrocarbon group which may have an ether bond, n _a1 is 0 to 2, and Ra ¹ is the above formula (a1-r-1) or (a1-r-2) It is an acid dissociable group represented by. Wa ¹ is a n _a2 +1 valent hydrocarbon group, n _a2 is 1 to 3, and Ra ² is an acid dissociation property represented by the above formula (a1-r-1) or (a1-r-3). It is a group. ]

In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically a methyl group or an ethyl group. Propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is most preferably a hydrogen atom or a methyl group in terms of industrial availability.

The hydrocarbon group for Va ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group as a divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is usually preferably saturated.
More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group having a ring in the structure, and the like.
Further, Va ¹ may have an ether bond (—O—) between carbon atoms of the divalent hydrocarbon group. One or two or more ether bonds may be present in Va ¹ .

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, more preferably 1 to 4, and most preferably 1 to 3.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those described above.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.
The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, and 6 to 6 carbon atoms. 15 is particularly preferable, and 6 to 10 is most preferable. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; some of the carbon atoms constituting the aromatic hydrocarbon ring are heterogeneous. Aromatic heterocycles substituted with atoms. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) A group in which one of the hydrogen atoms is substituted with an alkylene group (for example, arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) And a group obtained by further removing one hydrogen atom from the aryl group. The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

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

Specific examples of the structural unit represented by the formula (a1-1) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

  Specific examples of the structural unit represented by the formula (a1-2) are shown below.

As the structural unit (a1) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
The proportion of the structural unit (a1) in the component (A1) is preferably 10 to 80 mol%, more preferably 15 to 75 mol%, more preferably 20 to 70 mol%, based on all structural units constituting the component (A1). Is more preferable.
By setting the proportion of the structural unit (a1) to the lower limit value or more, a resist pattern can be easily obtained, and lithography properties such as sensitivity, resolution, and LWR are also improved. In addition, by setting 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 including a lactone-containing cyclic group, an —SO ₂ -containing cyclic group, or a carbonate-containing cyclic group.
The lactone-containing cyclic group, —SO ₂ — containing cyclic group or carbonate-containing cyclic group of the structural unit (a2) can be used to adhere the resist film to the substrate when the component (A1) is used for forming the resist film. It is effective in enhancing the sex.

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-containing cyclic group in the structural unit (a2) is not particularly limited, and any lactone-containing cyclic group can be used. Specific examples include groups represented by general formulas (a2-r-1) to (a2-r-7) shown below.

［式中、Ｒａ’^２１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は−ＳＯ_２−含有環式基であり；Ａ”は酸素原子（−Ｏ−）もしくは硫黄原子（−Ｓ−）を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり、ｎ’は０〜２の整数であり、ｍ’は０または１である。］

[Wherein, Ra ′ ²¹ each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or —SO ₂ -containing cyclic group; A ″ is an oxygen atom (—O—) or a sulfur atom (— S—) may be an alkylene group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom, n ′ is an integer of 0 to 2, and m ′ is 0 or 1. ]

In the general formula (a2-r-1) ~ (a2-r-7), the alkyl group in Ra ^'21, 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 in the ra ^'21, preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, groups of the the Ra 'group and an oxygen atom mentioned as the alkyl group in ²¹ (-O-) are linked and the like.
Examples of the halogen atom in Ra ′ ²¹ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
'Examples of the halogenated alkyl group for ^21, the Ra' Ra part or all of the hydrogen atoms of the alkyl group in ²¹ can be mentioned it has been substituted with the aforementioned halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

In —COOR ″ and —OC (═O) R ″ in Ra ′ ²¹ , R ″ is any hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or —SO ₂ -containing cyclic group. It is.
The alkyl group for R ″ may be linear, branched or cyclic, and preferably has 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.
Examples of the lactone-containing cyclic group for R ″ include the same groups as those represented by general formulas (a2-r-1) to (a2-r-7).
The carbonate-containing cyclic group for R ″ is the same as the carbonate-containing cyclic group described later, and specifically, groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively. Is mentioned.
The —SO ₂ — containing cyclic group in R ″ is the same as the later-described —SO ₂ — containing cyclic group, and specifically, is represented by the general formulas (a5-r-1) to (a5-r-4) And groups represented respectively by
As the hydroxyalkyl group in Ra ′ ²¹ , those having 1 to 6 carbon atoms are preferable, and specific examples include a group in which at least one hydrogen atom of the alkyl group in Ra ′ ²¹ is substituted with a hydroxyl group. .

In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A ″ is linear or branched. An alkylene group is preferable, and examples include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include the terminal of the alkylene group or carbon. between atoms -O- or -S- can be mentioned a group intervening, for example, _{-O-CH 2 -, - CH} 2 -O-CH 2 -, - S-CH 2 -, - CH 2 -S-CH _As A ″, an alkylene group having 1 to 5 carbon atoms or —O— is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is most preferable.

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

The “—SO ₂ -containing cyclic group” refers to a cyclic group containing a ring containing —SO ₂ — in the ring skeleton, specifically, the sulfur atom (S) in —SO ₂ — is It is a cyclic group that forms part of the ring skeleton of the cyclic group. The ring containing —SO ₂ — in the ring skeleton is counted as the first ring, and when it is only the ring, it is a monocyclic group, and when it has another ring structure, it is a polycyclic group regardless of the structure. Called. The —SO ₂ — containing cyclic group may be a monocyclic group or a polycyclic group.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton A cyclic group containing a sultone ring to be formed is preferable.
More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by general formulas (a5-r-1) to (a5-r-4) shown below.

［式中、Ｒａ’^５１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は−ＳＯ_２−含有環式基であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり、ｎ’は０〜２の整数である。］

[Wherein, Ra ′ ⁵¹ independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or —SO ₂ -containing cyclic group; A ″ is a carbon that may contain an oxygen atom or a sulfur atom It is a C 1-5 alkylene group, an oxygen atom or a sulfur atom, and n ′ is an integer of 0-2. ]

In general formulas (a5-r-1) to (a5-r-4), A ″ represents the general formulas (a2-r-2), (a2-r-3), and (a2-r-5). Same as A ″ in the middle.
As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in Ra ′ ⁵¹ , the above general formulas (a2-r-1) to ( a2-r-7) as in the same as those exemplified in the description of the Ra ^'21 of the like.
Specific examples of groups represented by general formulas (a5-r-1) to (a5-r-4) are shown below. “Ac” in the formula represents an acetyl group.

The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —O—C (═O) —O— in the ring skeleton. When the carbonate ring is counted as the first ring, the carbonate ring alone is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
Any carbonate ring-containing cyclic group can be used without any particular limitation. Specific examples include groups represented by the following general formulas (ax3-r-1) to (ax3-r-3).

［式中、Ｒａ’^ｘ３１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は−ＳＯ_２−含有環式基であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子でありｑ’は０または１である。］

[ ^Wherein , Ra ′ ^x31 each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or —SO ₂ -containing cyclic group; A ″ is a carbon that may contain an oxygen atom or a sulfur atom It is an alkylene group of formulas 1 to 5, an oxygen atom or a sulfur atom, and q ′ is 0 or 1. ]

In the general formulas (ax3-r-1) to (ax3-r-3), A ″ represents the general formulas (a2-r-2), (a2-r-3), (a2-r-5). Same as A ″ in the middle.
As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in Ra ′ ³¹ , the above general formulas (a2-r-1) to ( a2-r-7) as in the same as those exemplified in the description of the Ra ^'21 of the like.
Specific examples of groups represented by general formulas (ax3-r-1) to (ax3-r-3) are given below.

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

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

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Ya ²¹ is a single bond or a divalent linking group. La ²¹ represents —O—, —COO—, —CON (R ′) —, —OCO—, —CONHCO— or —CONHCS—, and R ′ represents a hydrogen atom or a methyl group. However, when La ²¹ is —O—, Ya ²¹ is not —CO—. Ra ²¹ is a lactone-containing cyclic group, a carbonate-containing cyclic group, or an —SO ₂ -containing cyclic group. ]

In formula (a2-1), R is the same as described above.
The divalent linking group of Ya ²¹ is not particularly limited, and preferred examples thereof include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

When Ya ²¹ is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

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

As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure (excluding two hydrogen atoms from the aliphatic hydrocarbon ring) Group), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and the cyclic aliphatic hydrocarbon group is a linear or branched chain fatty acid. Group intervening in the middle of the group hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
In the cyclic aliphatic hydrocarbon group, a part of carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing the hetero atom, —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, and —S (═O) ₂ —O— are preferable.

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

In the aromatic hydrocarbon group, a hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
Examples of the alkoxy group, the halogen atom and the halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

When Ya ²¹ is a divalent linking group containing a hetero atom, preferred examples of the linking group include —O—, —C (═O) —O—, —C (═O) —, and —O—C. (═O) —O—, —C (═O) —NH—, —NH—, —NH—C (═NH) — (H may be substituted with a substituent such as an alkyl group or an acyl group). _{.), - S -, -} S (= O) 2 -, - S (= O) 2 -O-, the formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 - C (═O) —O—, —C (═O) —O—Y ²¹ —, — [Y ²¹ —C (═O) —O] _{m ″} —Y ²² —, —Y ²¹ —O—C ( Group represented by ═O) —Y ²² — or —Y ²¹ —S (═O) ₂ —O—Y ²² —, wherein Y ²¹ and Y ²² each independently have a substituent. A divalent hydrocarbon group, It is an oxygen atom, m "is an integer of 0 to 3. ] Etc. are mentioned.
The divalent linking group containing a hetero atom is -C (= O) -NH-, -C (= O) -NH-C (= O)-, -NH-, -NH-C (= NH). In the case of-, the H may be substituted with a substituent such as an alkyl group or acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 -C (= O) -O -, - C (= O) -O-Y 21 -, - [Y 21 - C (═O) —O] _{m ″} —Y ²² —, —Y ²¹ —O—C (═O) —Y ²² — or —Y ²¹ —S (═O) ₂ —O—Y ²² —, wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, and the divalent hydrocarbon group is exemplified in the description of the divalent linking group. And (the divalent hydrocarbon group which may have a substituent).
Y ²¹ is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. preferable.
Y ²² is preferably a linear or branched aliphatic hydrocarbon group, and more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ″} —Y ²² —, m ″ is an integer of 0 to 3, preferably an integer of 0 to 2, Or 1 is more preferable, and 1 is particularly preferable. That is, the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ″} —Y ²² — is represented by the formula —Y ²¹ —C (═O) —O—Y ²² —. Especially preferred are groups represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} —, wherein a ′ is 1 to It is an integer of 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 10, and 1 to 8 An integer of 1 is preferable, an integer of 1 to 5 is more preferable, 1 or 2 is more preferable, and 1 is most preferable.

Ya ²¹ is preferably a single bond, an ester bond [—C (═O) —O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. .

In the formula (a2-1), Ra ²¹ is a lactone-containing cyclic group, an —SO ₂ -containing cyclic group, or a carbonate-containing cyclic group.
The lactone-containing cyclic group, -SO ₂ -containing cyclic group, and carbonate-containing cyclic group in Ra ²¹ are each represented by the general formulas (a2-r-1) to (a2-r-7) described above. Groups represented by general formulas (a5-r-1) to (a5-r-4), groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively. Are preferable.
Among them, a lactone-containing cyclic group or a —SO ₂ — containing cyclic group is preferable, and the general formulas (a2-r-1), (a2-r-2), (a2-r-6), (a2-r) The groups represented by -7) or (a5-r-1) are more preferable. Specifically, the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r- Any group represented by lc-6-1), (r-lc-7-1), (r-sl-1-1), and (r-sl-1-18) is more preferred.

  As the structural unit represented by the general formula (a2-1), more preferably, the structural unit represented by the following general formula (a2-1-1) or the general formula (a2-1-2) The structural unit represented is mentioned.

［式中、Ｒ及びＲａ^２１は、前記式（ａ２−１）におけるＲ及びＲａ^２１と同様である。Ｒａ^２２及びＲａ^２３はそれぞれ独立に水素原子又は炭素数１〜５のアルキル基である。ｎａ_２１は１〜３の整数である。］

Wherein, R and ^{Ra 21} are the same as R and ^{Ra 21} in the formula (a2-1). Ra ²² and Ra ²³ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. na ₂₁ is an integer of 1 to 3. ]

In the formula (a2-1-2), the alkyl groups of Ra ²² and Ra ²³ are the same as the alkyl group for R. When both Ra ²² and Ra ²³ are hydrogen atoms, or only one of Ra ²² and Ra ²³ is preferably an alkyl group (particularly preferably a methyl group).
na ₂₁ is preferably 1.

As the structural unit (a2) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
When the component (A1) has the structural unit (a2), the proportion of the structural unit (a2) is preferably 1 to 80 mol% with respect to the total of all the structural units constituting the component (A1). It is more preferably 10 to 70 mol%, further preferably 10 to 65 mol%, particularly preferably 10 to 60 mol%.
By setting the proportion of the structural unit (a2) to be equal to or higher than the lower limit value, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting the ratio to the upper limit value or less, a balance with other structural units is obtained. And various lithographic properties and pattern shapes are good.

(Structural unit (a3))
The structural unit (a3) is a structural unit (excluding those corresponding to the structural unit (a1) or the structural unit (a2)) containing a polar group-containing aliphatic hydrocarbon group.
It is considered that when the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) is increased and the resolution is improved.
Examples of the polar group of the polar group-containing aliphatic hydrocarbon group in the structural unit (a3) include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which part of the hydrogen atoms of the alkyl group is substituted with a fluorine atom. .
Examples of the aliphatic hydrocarbon group of the polar group-containing aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group having a ring in the structure, or a combination thereof. Can be mentioned.
Preferred examples of the polar group-containing aliphatic hydrocarbon group include groups represented by general formulas (a3-r-1) to (a3-r-3) shown below. In the following formula, “*” indicates a bond.

［式中、Ｗａ’^３１、Ｗａ’^３２及びＷａ’^３３はそれぞれ独立に（ｎ’＋１）価の脂肪族炭化水素基であり、ｎ’は１〜３の整数であり、Ｒａ’^３１及びＲａ’^３２はそれぞれ独立にフッ素原子またはフッ素化アルキル基である。］

[Wherein, Wa ′ ³¹ , Wa ′ ³² and Wa ′ ³³ are each independently an (n ′ + 1) -valent aliphatic hydrocarbon group, n ′ is an integer of 1 to 3, and Ra ′ ³¹ and Ra ^'32 are each independently a fluorine atom or a fluorinated alkyl group. ]

In the formulas (a3-r-1) to (a3-r-3), the aliphatic hydrocarbon group in Wa ′ ³¹ , Wa ′ ³² and Wa ′ ³³ may be saturated or unsaturated. Usually, it is preferably saturated.
The (n ′ + 1) valence is preferably 2 to 4, and more preferably 2 or 3.
Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a linear or branched aliphatic hydrocarbon group. And an aliphatic hydrocarbon group containing a ring in the structure.
Such a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in the structure are respectively the divalent linking groups of Ya ²¹ in the formula (a2-1). A hydrogen atom is removed from the aliphatic hydrocarbon group (straight chain or branched chain aliphatic hydrocarbon group, aliphatic hydrocarbon group containing a ring in the structure) described in the above so as to have an (n ′ + 1) valence. Groups.
In the aliphatic hydrocarbon group in Wa ′ ³¹ , Wa ′ ³² and Wa ′ ^33, a part of carbon atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom.
As the substituent containing the hetero atom, —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, and —S (═O) ₂ —O— are preferable.
In the formula (a3-r-3), Ra ′ ³¹ and Ra ′ ³² are a fluorine atom or a fluorinated alkyl group. As the fluorinated alkyl group, a fluorinated alkyl group having 1 to 5 carbon atoms is preferable.

  Specific examples of the groups represented by the general formulas (a3-r-1) to (a3-r-3) are shown below.

  The structural unit (a3) is preferably a structural unit represented by the following general formula (a3-1).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｌａ^３１は−ＣＯＯ−、−ＣＯＮ（Ｒ^３１’）−であり、Ｒ^３１’は水素原子またはメチル基を示す。Ｖａ^３１は２価の炭化水素基である。Ｌａ^３２は−Ｏ−、−ＣＯＯ−、−ＣＯＮ（Ｒ^３２’）−、−ＯＣＯ−、−ＣＯＮＨＣＯ−又は−ＣＯＮＨＣＳ−であり、Ｒ^３２’は水素原子またはメチル基を示す。ｎａ^３１は０〜３の整数であり、ｎａ^３１が２以上のとき、複数存在するＶａ^３１およびＬａ^３２はそれぞれ同じであっても異なっていてもよい。Ｒａ^３１は前記式（ａ３−ｒ−１）〜（ａ３−ｒ−３）のいずれかで表される基である。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. La ³¹ is —COO— or —CON (R ³¹ ′) —, and R ³¹ ′ represents a hydrogen atom or a methyl group. Va ³¹ is a divalent hydrocarbon group. La ³² is —O—, —COO—, —CON (R ³² ′) —, —OCO—, —CONHCO— or —CONHCS—, and R ³² ′ represents a hydrogen atom or a methyl group. na ³¹ is an integer of 0 to 3. When na ³¹ is 2 or more, a plurality of Va ³¹ and La ³² may be the same or different. Ra ³¹ is a group represented by any one of the formulas (a3-r-1) to (a3-r-3). ]

In the formula (a3-1), R is the same as described above.
Va ³¹ is a divalent hydrocarbon group, and examples thereof include the same divalent hydrocarbon groups as Ya ²¹ in the formula (a2-1).
Specific examples of the structural unit represented by the formula (a3-1) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

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

(Other structural units)
The component (A1) may further include other structural units that do not correspond to the structural units described above.
The other structural unit is not particularly limited as long as it is a structural unit that is not classified as the above-mentioned structural unit, and may be a resist resin for ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser), or the like. Many conventionally known ones can be used, and examples thereof include the structural unit (a4) shown below.

Structural unit (a4):
The structural unit (a4) is a structural unit containing an acid non-dissociable aliphatic cyclic group.
When the component (A1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. Moreover, the hydrophobicity of (A) component increases. The improvement in hydrophobicity is thought to contribute to the improvement of resolution, resist pattern shape, etc., particularly in the case of organic solvent development.
The “acid non-dissociable cyclic group” in the structural unit (a4) is generated when an acid is generated in the resist composition by exposure (for example, when an acid is generated from the component (A1) or the component (B) described later). In addition, the cyclic group remains in the structural unit as it is without dissociating even when the acid acts.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic cyclic group is preferable. Examples of the cyclic group include those similar to those exemplified for the structural unit (a1), such as for ArF excimer laser, for KrF excimer laser (preferably for ArF excimer laser), etc. A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include structural units represented by general formulas (a4-1) to (a4-7) shown below.

［式中、Ｒ^αは前記と同じである。］

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

The structural unit (a4) contained in the component (A1) may be one type or two or more types.
When the component (A1) has the structural unit (a4), the proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1). 3-20 mol% is more preferable.
By setting the proportion of the structural unit (a4) to the lower limit value or more, the effect of containing the structural unit (a4) can be sufficiently obtained, and by setting the proportion of the structural unit (a4) to the upper limit value or less, balance with other structural units can be obtained. It becomes easy.

As the component (A1), one type may be used alone, or two or more types may be used in combination.
Especially, it is preferable that (A1) component is a polymer which has the terminal group (I-1) mentioned above in the at least one terminal of a principal chain, and has the said structural unit (a1).
As such a polymer, the main chain is composed of a repeating structure of the structural unit (a1) and the structural unit (a2), and the main chain is composed of a repeating structure of the structural unit (a1) and the structural unit (a3). Preferred examples include those having a repeating structure of the structural unit (a1), the structural unit (a2), and the structural unit (a3).

The component (A1) is produced by polymerizing monomers that induce each constituent unit constituting the component (A1) such that at least one end of the main chain is the terminal group (I-1). be able to. As the monomer (monomer) for deriving each structural unit, a synthesized one or a commercially available one may be used.
In the resist composition of this embodiment, the component (A1) is a compound represented by the following general formula (I) (hereinafter referred to as the general formula (I)) because good lithographic characteristics and a resist pattern shape are easily obtained when used in the resist composition. A radical polymer obtained by radical polymerization using a radical polymerization initiator composed of “compound (I)” is preferred.

［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は単結合、又は−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−若しくは−ＮＨ−Ｃ（＝ＮＨ）−を含んでいてもよい２価の連結基である。Ｒ^２は炭素数４〜２０の第３級エステル型酸解離性基（ただし、ｔｅｒｔ−ブチル基を除く）である。式中の複数のＲ^１、Ｚ、Ｘ及びＲ^２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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). A plurality of R ¹ , Z, X and R ² in the formula may be the same or different. ]

In the formula ^{(I), R 1, Z} , X, R 2 is, ^R 1, Z in formula (I-1), X, are each the ^{R 2} identical.
In the formula (I), a plurality of R ¹ , Z, X, and R ² may be the same or different from each other, but are preferably the same industrially.

Specific examples of compound (I) are shown below. In the following formulae, R ² has the same meaning as described above.

As the compound (I), compounds represented by the formulas (I1) to (I6) are preferable, and a compound represented by the formula (I1) is particularly preferable.
Specific examples of the compound represented by the formula (I1) are shown below.

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

In the resist composition of this embodiment, the component (A) may be used alone or in combination of two or more.
The resist composition of this embodiment may contain, as the component (A), a base material component that does not correspond to the component (A1) and whose solubility in the developer is changed by the action of an acid.
In the resist composition of this embodiment, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<Other ingredients>
In addition to the component (A), the resist composition of this embodiment may further contain an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “component (B)”).

[Component (B)]
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used.
Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, and diazomethanes such as poly (bissulfonyl) diazomethanes. Examples include an acid generator, a nitrobenzyl sulfonate acid generator, an imino sulfonate acid generator, and a disulfone acid generator. Of these, it is preferable to use an onium salt acid generator.

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

［式中、Ｒ^１０１、Ｒ^１０４〜Ｒ^１０８はそれぞれ独立に置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、または置換基を有していてもよい鎖状のアルケニル基である。Ｒ^１０４、Ｒ^１０５は、相互に結合して環を形成していてもよい。Ｒ^１０２はフッ素原子または炭素数１〜５のフッ素化アルキル基である。Ｙ^１０１は単結合または酸素原子を含む２価の連結基である。Ｖ^１０１〜Ｖ^１０３はそれぞれ独立に単結合、アルキレン基、またはフッ素化アルキレン基である。Ｌ^１０１〜Ｌ^１０２はそれぞれ独立に単結合または酸素原子である。Ｌ^１０３〜Ｌ^１０５はそれぞれ独立に単結合、−ＣＯ−又は−ＳＯ_２−である。ｍは１以上の整数であって、Ｍ’^ｍ＋はｍ価のオニウムカチオンである。］

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

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

Cyclic group which may have a substituent:
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. 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.

The aromatic hydrocarbon group for R ¹⁰¹ is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, further preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic ring of the aromatic hydrocarbon group in R ¹⁰¹ include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or a part of carbon atoms constituting these aromatic rings substituted with a heteroatom. An aromatic heterocyclic ring is mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group in R ¹⁰¹ is a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and one of the hydrogen atoms of the aromatic ring is alkylene. And a group substituted with a group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

Examples of the cyclic aliphatic hydrocarbon group for R ¹⁰¹ include an aliphatic hydrocarbon group containing a ring in the structure.
As the aliphatic hydrocarbon group containing a ring in this structure, an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), an alicyclic hydrocarbon group is linear or branched Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group in which one or more hydrogen atoms have been removed from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms. Adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
Among these, the cyclic aliphatic hydrocarbon group for R ¹⁰¹ is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane or polycycloalkane, and more preferably a group obtained by removing one hydrogen atom from a polycycloalkane. An adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

The linear or branched aliphatic hydrocarbon group that may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and 1 to 4 carbon atoms. Is more preferable, and 1-3 are most preferable.
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.

In addition, the cyclic hydrocarbon group for R ¹⁰¹ may contain a hetero atom such as a heterocyclic ring. Specifically, the lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), and the general formulas (a5-r-1) to (a5-r- -SO 2 respectively represented by 4) _- containing cyclic group, heterocyclic group listed other less like.

Examples of the substituent in the cyclic hydrocarbon group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group (—C (═O) —), an ether bond (—O—). ), An ester bond (—C (═O) —O—), a nitro group, and the like.
The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent, a part or all of hydrogen atoms such as an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group, And a group substituted with a halogen atom.
A carbonyl group (—C (═O) —), an ether bond (—O—), and an ester bond (—C (═O) —O—) as a substituent group are methylene groups ( It is a group that substitutes —CH ₂ —).

A chain-like alkyl group which may have a substituent:
The chain alkyl group for R ¹⁰¹ may be either linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

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

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group (—C (═O) —), an ether bond (—O—). ), An ester bond (—C (═O) —O—), a nitro group, an amino group, the cyclic group in R ^{101, and} the like.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent, a part or all of hydrogen atoms such as an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group, And a group substituted with a halogen atom.
A carbonyl group (—C (═O) —), an ether bond (—O—), or an ester bond (—C (═O) —O—) as a substituent constitutes a chain alkyl group or alkenyl group. It is a group that substitutes a methylene group (—CH ₂ —).

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The chain alkyl group which may have a substituent in R ″ ¹⁰¹ is preferably the group exemplified as the chain alkyl group in R ^101. The chain in R ″ ¹⁰³ has a substituent. The good chain alkenyl group is preferably the group exemplified as the chain alkenyl group in R ¹⁰¹ .

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

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

{Cation part}
In formulas (b-1), (b-2), and (b-3), M ′ ^{m +} is an m-valent onium cation, and a sulfonium cation and an iodonium cation are preferable. Specifically, organic cations respectively represented by the following general formulas (ca-1) to (ca-4) are preferable.

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

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

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

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

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

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

^{R 201 ~R 203, R 206 ~R} 207, R 211 ~R 212 , when bonded to each other to form a ring with the sulfur atom, a sulfur atom, an oxygen atom, or a hetero atom such as nitrogen atom, carbonyl _{group, -SO -, - SO 2 -} , - SO 3 -, - COO -, - CONH- , or -N _(R N) - (. the _{R N} is an alkyl group having 1 to 5 carbon atoms), etc. You may couple | bond through the functional group of. As the ring to be formed, one ring containing a sulfur atom in the ring skeleton in the formula is preferably a 3- to 10-membered ring, particularly a 5- to 7-membered ring, including the sulfur atom. preferable. Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydro A thiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.

R ^{208 to} R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferable. A ring may be formed.

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

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

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

  Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following formulas (ca-1-1) to (ca-1-67), respectively.

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

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

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

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

  Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis (4-tert-butylphenyl) iodonium cation.

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

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

Among these, the cation part [M ′ ^{m +} ] is preferably a cation represented by the general formula (ca-1), and each cation represented by the formulas (ca-1-1) to (ca-1-67). Is more preferable.

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

[(D) component]
In the resist composition of this embodiment, in addition to the component (A), or in addition to the components (A) and (B), an acid diffusion controller component (hereinafter referred to as “component (D)”). You may contain.
The component (D) acts as a quencher (acid diffusion controller) that traps acid generated by exposure from the components (A) and (B).
The component (D) may be a photodegradable base (D1) (hereinafter referred to as “component (D1)”) that is decomposed by exposure and loses acid diffusion controllability, and includes a component that does not correspond to the component (D1). It may be a nitrogen organic compound (D2) (hereinafter referred to as “component (D2)”).

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

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

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

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

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

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

..Cation part In the formula (d1-1), M ^{m +} is an m-valent organic cation.
As the organic cation of M ^{m +} , those similar to the cations represented by the general formulas (ca-1) to (ca-4) are preferably exemplified, and the formulas (ca-1-1) to (ca Cations represented by -1-67) are more preferable.
As the component (d1-1), one type may be used alone, or two or more types may be used in combination.

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

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

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

{(D1-3) component}
.. Anion moiety In formula (d1-3), Rd ³ has a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. A chain alkenyl group which may be the same as R ^{101 in} formula (b-1), and includes a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group. It is preferable that Among them, a fluorinated alkyl group is preferable, and the same as the fluorinated alkyl group for Rd ¹ is more preferable.

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

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

Examples of the cyclic group for Rd ⁴ include those similar to R ¹⁰¹ in the above formula (b-1), such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group excluding one or more hydrogen atoms, or an aromatic group such as a phenyl group or a naphthyl group is preferred. When Rd ⁴ is an alicyclic group, the resist composition is well dissolved in an organic solvent, whereby the lithography properties are improved. In addition, when Rd ⁴ is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition is excellent in light absorption efficiency, and sensitivity and lithography characteristics are good.

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

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

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

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

(Production method of component (D1))
The manufacturing method of said (d1-1) component and (d1-2) component is not specifically limited, It can manufacture by a well-known method.
Moreover, the manufacturing method of (d1-3) component is not specifically limited, For example, it manufactures similarly to the method of US2012-0149916 gazette.

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

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

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

As the component (D2), an aromatic amine may be used.
Examples of the aromatic amine include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine and the like.

(D2) A component may be used independently and may be used in combination of 2 or more type.
(D2) A component is normally used in 0.01-5 mass parts with respect to 100 mass parts of (A) component. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

[(E) component]
The resist composition according to the present embodiment includes, as an optional component, organic carboxylic acid, phosphorus oxo acid, and derivatives thereof for the purpose of preventing sensitivity deterioration, improving the resist pattern shape, stability with 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 include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
(E) A component is normally used in 0.01-5 mass parts with respect to 100 mass parts of (A) component.

[(F) component]
The resist composition of this embodiment may contain a fluorine additive (hereinafter referred to as “component (F)”) in order to impart water repellency to the resist film.
Examples of the component (F) include those described in JP 2010-002870 A, JP 2010-032994 A, JP 2010-277043 A, JP 2011-13569 A, and JP 2011-128226 A. These fluorine-containing polymer compounds 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 the polymer include a polymer (homopolymer) composed only of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1). A copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate.

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

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

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

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

(F) As for the weight average molecular weight (Mw) (polystyrene conversion reference | standard by gel permeation chromatography), 1000-50000 are preferable, 5000-40000 are more preferable, and 10000-30000 are the most preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
The molecular weight dispersity (Mw / Mn) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

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

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

[(S) component]
The resist composition of this embodiment can be produced by dissolving a resist material in an organic solvent (hereinafter sometimes referred to as “(S) component”).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol Polyhydric alcohols such as: ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, etc., compounds having an ester bond, monohydric ethers of the polyhydric alcohols or compounds having an ester bond , Monoalkyl ethers such as monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having an ether bond [in these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and lactic acid Esters such as methyl, 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, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. An aromatic organic solvent, dimethyl sulfoxide (DMSO), etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA: EL or cyclohexanone is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. . Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferable.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
(S) The usage-amount of a component is not specifically limited, It is a density | concentration which can be apply | coated to a board | substrate etc., and is suitably set according to a coating film thickness. Generally, it is used so that the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

The resist composition of the present invention is excellent in lithography properties such as sensitivity, exposure margin, mask reproducibility, and roughness reduction, and pattern shape. The reason why such an effect is obtained is not clear, but is presumed as follows.
The polymer contained in the resist composition of the present invention has a tertiary ester type acid dissociable group “—R ² ” which is dissociated by the action of an acid at the end of the main chain. The polarity of the polymer is increased by the dissociation of the tertiary ester type acid dissociable group by the action of an acid. And, as the polarity increases, the solubility in the developer changes relatively, and it becomes easier to obtain a dissolution contrast between the exposed and unexposed areas. The
Of the tertiary ester type acid dissociable groups, the tert-butyl group is less likely to be dissociated by the action of an acid than other tertiary ester type acid dissociable groups. In addition, the tertiary ester type acid dissociable group in the present invention is different in ease of dissociation and dissociated decomposition products by the action of an acid even when compared with an acetal type acid dissociable group. For this reason, it is considered that the tertiary ester type acid dissociable group and the tert-butyl group or acetal type acid dissociable group in the present invention are different in the influence on the lithography characteristics and the pattern shape.

  Further, when the polymer contained in the resist composition of the present invention is a component (A1) whose polarity is increased by the action of an acid and its solubility in a developing solution is changed, the third end of the main chain terminal is used. The secondary ester type acid dissociable group is easily distributed uniformly in the resist film. As a result, since the tertiary ester type acid dissociable group is dissociated at the end of the main chain at the exposed portion, the polarity can be increased uniformly throughout the exposed portion, so that the above effect is likely to be obtained satisfactorily. It is done.

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

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

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

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

Examples of the alkali developer used for the development treatment in the alkali development process include 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used for the development process in the solvent development process is not particularly limited as long as it can dissolve the component (A) (component (A) before exposure). It can be selected as appropriate. Specific examples include ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, ether solvents, and other polar solvents, hydrocarbon solvents, and the like.
The ketone solvent is an organic solvent containing C—C (═O) —C in the structure. The ester solvent is an organic solvent containing C—C (═O) —O—C in the structure. An alcohol solvent is an organic solvent containing an alcoholic hydroxyl group in the structure, and “alcoholic hydroxyl group” means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. A nitrile solvent is an organic solvent containing a nitrile group in its structure. The amide solvent is an organic solvent containing an amide group in the structure. The ether solvent is an organic solvent containing C—O—C in the structure.
Among organic solvents, there are organic solvents that contain multiple types of functional groups that characterize each of the above solvents in the structure, but in that case, any of the solvent types that contain the functional groups of the organic solvent is applicable. Shall. For example, diethylene glycol monomethyl ether shall correspond to both of the alcohol solvent and the ether solvent in the above classification.
The hydrocarbon solvent is a hydrocarbon solvent made of a hydrocarbon which may be halogenated and having no substituent other than a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Among the above, the organic solvent contained in the organic developer is preferably a polar solvent, and is preferably a ketone solvent, an ester solvent, a nitrile solvent, or the like.

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

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

  Examples of the nitrile solvent include acetonitrile, propionitryl, valeronitrile, butyronitryl and the like.

A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. The surfactant is not particularly limited. For example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used. As the surfactant, a nonionic surfactant is preferable, and a fluorine-based surfactant or a silicon-based surfactant is more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0. 5 mass% is more preferable.

  The development process can be performed by a known development method. For example, a method in which a support is immersed in a developer for a certain period of time (dip method), a developer is raised on the surface of the support by surface tension, and is left for a certain period of time. (Paddle method), spraying developer on the surface of the support (spray method), coating the developer while scanning the developer coating nozzle at a constant speed on the support rotating at a constant speed The method to continue (dynamic dispensing method) etc. are mentioned.

As the organic solvent contained in the rinsing liquid used for the rinsing process after the development process in the solvent developing process, for example, an organic solvent that is difficult to dissolve the resist pattern is selected as appropriate from the organic solvents used as the organic solvent used in the organic developer. Can be used. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, and at least one selected from alcohol solvents and ester solvents is preferable. More preferred are alcohol solvents.
The alcohol solvent used for the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. It is done. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol or 2-hexanol is more preferable.
Any one of these organic solvents may be used alone, or two or more thereof may be mixed and used. Moreover, you may mix and use the organic solvent and water other than the above. However, in consideration of development characteristics, the blending amount of water in the rinsing liquid is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, more preferably 3% by mass or less based on the total amount of the rinsing liquid. Is particularly preferred.
A well-known additive can be mix | blended with a rinse liquid as needed. Examples of the additive include a surfactant. Examples of the surfactant are the same as those described above, and a nonionic surfactant is preferable, and a fluorine-based surfactant or a silicon-based surfactant is more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0.5% by mass with respect to the total amount of the rinse liquid. % Is more preferable.

  The rinse treatment (washing treatment) using the rinse liquid can be performed by a known rinse method. Examples of the method include a method of continuously applying a rinsing liquid on a support rotating at a constant speed (rotary coating method), a method of immersing the support in a rinsing liquid for a predetermined time (dip method), and the surface of the support. And a method of spraying a rinse liquid (spray method).

≪Compound≫
A third 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は単結合、又は−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−若しくは−ＮＨ−Ｃ（＝ＮＨ）−を含んでいてもよい２価の連結基である。Ｒ^２は炭素数４〜２０の第３級エステル型酸解離性基（ただし、ｔｅｒｔ−ブチル基を除く）である。式中の複数のＲ^１、Ｚ、Ｘ及びＲ^２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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). A plurality of R ¹ , Z, X and R ² in the formula may be the same or different. ]

In the formula ^{(I), R 1, Z} , X, R 2 is, ^R 1, Z in the formula (I-1), respectively similar X, and ^{R 2.}
In the formula (I), a plurality of R ¹ , Z, X, and R ² may be the same or different from each other, but are preferably the same industrially.
The compound of the third aspect of the present invention is the same as the compound (I) described above.

≪Radical polymerization initiator≫
The fourth aspect of the present invention is a radical polymerization initiator comprising the compound of the third aspect.
The radical polymerization initiator can be used as a polymerization initiator for polymerizing a monomer in a radical polymerization reaction for synthesizing a polymer. Moreover, the radical polymerization initiator of this embodiment has a tertiary ester type acid dissociable group (excluding a tert-butyl group) at the terminal. This tertiary ester-type acid dissociable group is dissociated by the action of an acid and the bond is cleaved with the oxygen atom to which the tertiary ester-type acid dissociable group is bonded. Thereby, after the tertiary ester-type acid dissociable group is dissociated, a carboxy group is formed at the terminal and the polarity is increased. Therefore, the radical polymerization initiator of this embodiment can be suitably used for radical polymerization of a polymer used in the 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 this embodiment, 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 the structural units (a1) to (a4) described above.

≪Method for producing compound≫
A fifth aspect of the present invention is a method for producing the compound of the third aspect, which is represented by a compound represented by the following general formula (i-1) and the following general formula (i-2). It is a manufacturing method of a compound including the process with which a compound is made to react.

［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は単結合、又は−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−若しくは−ＮＨ−Ｃ（＝ＮＨ）−を含んでいてもよい２価の連結基である。Ｒ^２は炭素数４〜２０の第３級エステル型酸解離性基（ただし、ｔｅｒｔ−ブチル基を除く）である。式中の複数のＲ^１、Ｚ及びＸ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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). A plurality of R ¹ , Z and X in the formula may be the same or different. ]

In the formula ^{(i-1), R 1} , Z, X is, ^R 1, Z in the formula (I-1), respectively similar to the X. In the formula (i-1), a plurality of R ¹ , Z, and X may be the same or different from each other, but are preferably the same industrially.
In the formula (i-2), ^{R 2} is the same as ^{R 2} in the formula (I-1).

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

As compound (i-1) and compound (i-2), commercially available compounds or synthesized compounds may be used, respectively.
The method for obtaining compound (I) by reacting compound (i-1) with compound (i-2) is not particularly limited, and compound (i-1) and compound (i) are present in the presence of a base. -2) and preferably a condensing agent in an organic solvent, and then washing and collecting the reaction mixture.
The base in the above reaction is not particularly limited, and examples thereof include tertiary amines such as potassium carbonate and triethylamine, aromatic amines such as pyridine and dimethylaminopyridine, and the like. Or two or more of them 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), and 0.5 to 20 More preferably, it is part by mass. A solvent may be used individually by 1 type and may use 2 or more types together.
Examples of the condensing agent include carbodiimide reagents such as diisopropylcarbodiimide and dicyclohexylcarboximide.
About 0.5-5 mol is preferable with respect to 1 mol of compound (i-1), and, as for the usage-amount of the compound (i-2) in the said reaction, about 0.8-4 mol is more preferable.

The reaction time in the above reaction is appropriately determined depending on the reactivity between the compound (i-1) and the compound (i-2), the reaction temperature, etc., and is usually preferably 1 to 80 hours, more preferably 3 to 60 hours. .
The reaction temperature in the above reaction is preferably 30 ° C. or less, and more preferably about 0 to 25 ° 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 or chromatography 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 sixth aspect of the present invention is a polymer having a group represented by the following general formula (I-1) (terminal group (I-1)) at at least one terminal of the main chain.
By having the terminal group (I-1), the polymer according to this embodiment can be converted into a tertiary ester type acid dissociable group (however, a tert-butyl group) in the terminal group (I-1) by the action of an acid. Are dissociated, and a carboxy group is formed at the terminal to increase the polarity. Thereby, when it uses for a resist composition, the solubility with respect to the developing solution of a resist film changes in resist pattern formation. That is, the solubility increases with respect to an alkaline developer, and the solubility decreases with respect to a developer containing an organic solvent.

［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は単結合、又は−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−若しくは−ＮＨ−Ｃ（＝ＮＨ）−を含んでいてもよい２価の連結基である。Ｒ^２は炭素数４〜２０の第３級エステル型酸解離性基（ただし、ｔｅｒｔ−ブチル基を除く）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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). ]

In the formula ^{(I), R 1, Z} , X, R 2 is, ^R 1, Z in the formula (I-1), respectively similar X, and ^{R 2.}

The polymer of the present embodiment may have any terminal group (I-1) at at least one end of the main chain, and other constitutions (for example, constitutional units constituting the polymer) Depending on the application, known ones can be used.
The polymer of this embodiment is useful for a resist composition.
The polymer of this embodiment is particularly useful as a base component of a chemically amplified resist composition or as an additive component arbitrarily blended in the resist composition. Among these, it is particularly preferable to use as a base material component of a chemically amplified resist composition. About the structure of the polymer used as a base material component, it is as the component (A1) mentioned above.

  As the polymer of this embodiment, a polymer that is a radical polymer obtained by radical polymerization using a radical polymerization initiator composed of a compound represented by the following general formula (I) is preferably exemplified. The compound represented by the following general formula (I) is the same as the compound (I) described above.

［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は単結合、又は−Ｏ−Ｃ（＝Ｏ）−、−ＮＨ−Ｃ（＝Ｏ）−若しくは−ＮＨ−Ｃ（＝ＮＨ）−を含んでいてもよい２価の連結基である。Ｒ^２は炭素数４〜２０の第３級エステル型酸解離性基（ただし、ｔｅｒｔ−ブチル基を除く）である。式中の複数のＲ^１、Ｚ、Ｘ及びＲ^２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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). A plurality of R ¹ , Z, X and R ² in the formula may be the same or different. ]

The radical polymerization can be carried out using a known method except that the compound represented by the general formula (I) is used as a radical polymerization initiator.
In radical polymerization, one radical polymerization initiator may be used alone, or two or more radical polymerization initiators may be used in combination.

  Below, the manufacture example of the polymer of this aspect is shown. In the following production examples, a monomer represented by formula (m) (hereinafter referred to as “radical polymerization initiator (I)”) using a radical polymerization initiator composed of a compound represented by formula (I) (hereinafter referred to as “radical polymerization initiator (I)”). A synthetic route through which radical polymerization of the monomer (m) ”) is schematically shown. However, the synthesis route of the polymer is not limited to the following production examples.

［式中、Ｒ^１、Ｚ、Ｘ、Ｒ^２は、前記式（Ｉ−１）におけるＲ^１、Ｚ、Ｘ、Ｒ^２と同じである。Ｒは前記Ｒと同じである。Ｘ^００は側鎖部である。］

^Wherein, R 1, Z, X, ^{R 2} is the same ^R 1, Z, X, and ^{R 2} in the formula (I-1). R is the same as R. ^X00 is a side chain part. ]

In the synthesis route, the radical polymerization initiator (I) is decomposed by the action of heat or light to generate nitrogen gas (N ₂ ) and carbon radicals.
Next, the carbon radical acts on the monomer (m), and the polymerization of the monomers (m) proceeds to obtain the polymer (PI).
The resulting polymer (PI) has a tertiary ester type acid dissociable group that is dissociated by the action of an acid at one end of the main chain. This “tertiary ester type acid dissociable group” is a residue derived from the radical polymerization initiator (I) (the above-mentioned terminal group (I-1)).

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 ( I-01) (hereinafter, this polymer is referred to as “polymer (I-01)”; a precursor polymer), and a terminal group of the main chain of the precursor polymer is “ R ² —O— ”(where R ² is the same as described above) is introduced (a hydrogen atom at the end of the main chain is substituted). Known repeating units can be used as the repeating unit constituting the polymer (I-01).
Introduction of “R ² —O—” can be carried out using a conventionally known method. For example, a polymer (I-01) and a compound (i-2) represented by the following general formula (i-2) -2) can be reacted (esterified). 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、Ｒ^２はそれぞれ前記同様である。］

[Wherein R ¹ , Z, X and R ² are the same as defined above. ]

EXAMPLES Hereinafter, 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).
In this example, the compound represented by the chemical formula (1) is referred to as “compound (1)”, and the same applies to compounds represented by other chemical formulas.

≪Production of compound≫
[Example 1: Synthesis of compound (IA)]
Under a nitrogen atmosphere, ACVA (19.6 g) and Alcohol-I (25 g) were added to dichloromethane (200 g), and the mixture was stirred at room temperature. Diisopropylcarbodiimide (24 g) was added thereto and stirred for 10 minutes. Thereafter, dimethylaminopyridine (3.4 g) was added as a catalyst and reacted at room temperature for 24 hours. The suspended reaction solution was filtered and the filtrate was recovered. Thereafter, washing with dilute hydrochloric acid and washing with water were performed, followed by concentration under reduced pressure, and crystallization was performed by adding n-hexane thereto to obtain 8.6 g of the target compound (IA).
The obtained compound (IA) was subjected to NMR measurement, and the structure was identified from the following results.
¹ H-NMR (400 MHz, DMSO-d6): δ (ppm) = 2.1-2.42 (m, 8H), 1.83 to 2.08 (m, 8H), 1.51-1.72 (M, 18H), 0.82 (t, 6H).

[Example 2: Synthesis of compound (IB)]
Except that Alcohol-I was changed to Alcohol-II, the target compound (IB) was obtained in the same manner as in Example 1.
The obtained compound (IB) was subjected to NMR measurement, and the structure was identified from the following results.
¹ H-NMR (400 MHz, DMSO-d6): δ (ppm) = 2.34−2.54 (m, 8H, CH ₂ CH ₂ (C═O)), 1.62-1.94 (m, _{32H, Adamantane + CH 2 CH 3} ), 1.15-1.82 (m, 6H, CH 3), 0.98 (t, 6H, CH 3).

[Example 3: Synthesis of compound (IC)]
The target compound (IC) was obtained in the same manner as in Example 1 except that Alcohol-I was changed to Alcohol-III.
The obtained compound (IC) was subjected to NMR measurement, and the structure was identified from the following results.
¹ H-NMR (400 MHz, DMSO-d6): δ (ppm) = 2.34−2.54 (m, 8H, CH ₂ CH ₂ (C═O)), 1.15 to 1.82 (m, 22H, CH ₃ + CH ₂ ), 0.92 (t, 6H, CH ₃ ).

≪Production of polymer≫
[Example 4: Production of polymer (1)]
Under a nitrogen atmosphere, 33.1 g of methyl ethyl ketone (MEK) was placed in a flask connected with a thermometer, a reflux pipe, a stirrer, and an N ₂ introduction pipe, and the internal temperature was raised to 80 ° C. while stirring.
Separately, 20.0 g (117.5 mmol) of monomer (1), 15.4 g (91.8 mmol) of monomer (12), and 12.0 g (50.7 mmol) of monomer (17) Dissolved in 9 g MEK. To this solution, 13.52 g (28.6 mmol) of initiator (IA) as a 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 a methanol / water mixed solution, and a polymer was precipitated. The precipitated white powder was filtered off, washed with a methanol / water mixed solution, and then decompressed. After drying, 41 g of the target polymer (1) was obtained.
The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement for this polymer (1) was 7700, and the molecular weight dispersity (Mw / Mn) was 1.64. 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 = 45/35/20.

[Examples 5 to 25: Synthesis of polymers (2) to (22)]
For the polymers (2) to (22), the following monomers (1) to (20) for deriving the structural units constituting the respective polymers were used in the molar ratios shown in Tables 1 and 2, Production was carried out in the same manner as in Example 4 except that the polymerization initiators shown were used.

  For the obtained polymers (1) to (22), the polymerization initiator used, the weight average molecular weight (Mw) and the molecular weight dispersity (Mw / Mn) are shown in Tables 1 and 2.

[Comparative Example 1: Synthesis of polymer (23)]
Under a nitrogen atmosphere, 33.1 g of methyl ethyl ketone (MEK) was placed in a flask connected with a thermometer, a reflux pipe, a stirrer, and an N ₂ introduction pipe, and the internal temperature was raised to 80 ° C. while stirring.
Separately, 20.0 g (117.5 mmol) of monomer (1), 15.4 g (91.8 mmol) of monomer (12), and 12.0 g (50.7 mmol) of monomer (17) Dissolved in 9 g MEK. To this solution, 6.59 g (28.6 mmol) of initiator (V-601) as a 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, and the reaction solution was cooled to room temperature.
The obtained reaction polymerization solution was dropped into a large amount of a methanol / water mixed solution, and a polymer was precipitated. The precipitated white powder was filtered off, washed with a methanol / water mixed solution, and then decompressed. After drying, 42 g of the target polymer (23) was obtained.
The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement for this polymer (23) was 7900, and the molecular weight dispersity (Mw / Mn) was 1.67. 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 = 45/35/20.

[Comparative Examples 2 to 5: Synthesis of Polymers (24) to (27)]
Polymers (24) to (27) are prepared by using the following monomers (1) to (20) for deriving structural units constituting the respective polymers at molar ratios shown in Table 2, and polymerization initiators shown in Table 2. Were produced in the same manner as in Comparative Example 1 except that each was used.

  For the obtained polymers (23) to (27), the polymerization initiator used, the weight average molecular weight (Mw) and the molecular weight dispersity (Mw / Mn) are also shown in Table 2. The structure of the polymerization initiator used is shown below.

<< Preparation of resist composition >>
[Examples 26 to 68, Comparative Examples 6 to 15]
Resist compositions were prepared by mixing and dissolving the components shown in Tables 3-6.

Each abbreviation in Tables 3-6 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1 to (A) -27: Polymers (1) to (27) above.
(B) -1: The following compound (B) -1.
(D) -1: The following compound (D) -1.
(D) -2: The following compound (D) -2.
(E) -1: salicylic acid.
(F) -1: The following copolymer (F) -1 [composition ratio of copolymer 1 / m = 77/23 (molar ratio), Mw = 23100, Mw / Mn = 1.78].
(S) -1: γ-butyrolactone.
(S) -2: Mixed solvent of PGMEA / PGME / cyclohexanone = 45/30/25 (mass ratio).

<< Formation of resist pattern (1) >>
[Alkali development process]
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 resist composition of each example is applied onto the organic antireflection film using a spinner, prebaked (PAB) on a hot plate at a temperature of 110 ° C. for 60 seconds, and dried. As a result, a resist film having a thickness of 80 nm was formed.
Next, an ArF excimer laser (193 nm) was applied to the resist film using an ArF immersion exposure apparatus NSR-S609B (Nikon Corporation; NA (numerical aperture) = 1.07, Dipole 0.97 / 0.78, w / polano). ) Was selectively irradiated through a mask pattern (6% halftone).
Then, a post-exposure heating (PEB) treatment was performed at a temperature of 95 ° C. for 60 seconds, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C. For 10 seconds, and then shaken and dried.
As a result, in each example, a 1: 1 line and space pattern (hereinafter referred to as “LS pattern”) having a line width of 50 nm and a pitch of 100 nm was formed.
The optimum exposure dose EOP (sensitivity; mJ / cm ² ) at which the LS pattern was formed was determined. The results are also shown in Table 7.

[Evaluation of exposure margin (EL margin)]
The exposure amount when a 1: 1 line and space pattern line 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 Table 7.
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 variation of the exposure amount.

[Evaluation of mask error factor (MEF)]
According to the same procedure as the formation of the resist pattern, a mask pattern targeting an LS pattern having a line width of 50 nm and a pitch of 100 nm and a mask pattern targeting an LS pattern having a line width of 55 nm and a pitch of 100 nm are used. LS patterns were formed respectively, and the MEF value was obtained from the following equation. The results are shown in Table 7.
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.

[Evaluation of line width roughness (LWR)]
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 determined by a length measurement SEM (scanning electron microscope, acceleration voltage 300 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). 400 points were measured in the longitudinal direction, and a triple value (3s) of the standard deviation (s) was obtained from the result, and a value averaged for 3s at 400 points was calculated as a scale indicating LWR. The results are shown in Table 7 as “LWR (nm)”.
A smaller value of “LWR (nm)”, that is, 3 s means that the roughness of the line width is smaller and an LS pattern having a more uniform width is obtained.

[Evaluation of pattern shape]
The cross-sectional shape of the pattern formed by 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 Table 7.
○: The rectangularity is high and good.
Δ: Slightly T-top shape.
X: Top shape is round or T-top shape.

  From the results of Table 7, the resist compositions of Examples 26 to 46 to which the present invention is applied are superior in lithography properties (EL margin, MEF, LWR) and pattern shape as compared with the resist compositions of Comparative Examples 6 to 10. I was able to confirm.

<< Formation of resist pattern (2) >>
[Solvent development process]
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 resist composition of each example is applied onto the organic antireflection film using a spinner, prebaked (PAB) on a hot plate at a temperature of 110 ° C. for 60 seconds, and dried. As a result, a resist film having a thickness of 100 nm was formed.
Next, an ArF excimer laser (193 nm) was applied to the resist film using an ArF immersion exposure apparatus NSR-S609B (Nikon Corporation; NA (numerical aperture) = 1.07, Annual 0.97 / 0.78, w / polano). ) Was selectively irradiated through a mask pattern (6% halftone).
Then, a post-exposure heating (PEB) treatment was performed at a temperature of 90 ° C. for 60 seconds, and further, solvent development was performed with butyl acetate at 23 ° C. for 13 seconds, followed by shake-off drying.
As a result, in each example, a contact hole pattern (hereinafter referred to as “CH pattern”) in which holes having a diameter of 55 nm are arranged at equal intervals (pitch 110 nm) was formed.
The optimum exposure dose EOP (sensitivity; mJ / cm ² ) at which the LS pattern was formed was determined. The results are also shown in Table 8.

[Evaluation of exposure margin (EL margin)]
The exposure amount when the hole diameter of the CH pattern is formed within the range of ± 5% (52.25 nm to 57.75 nm) of the target dimension (hole diameter 55 nm) is obtained, and the EL margin (unit:%) is obtained by the following equation. Was calculated. Table 8 shows the obtained results.
EL margin (%) = (| E3-E4 | / EOP) × 100
E3: Exposure amount when forming a CH pattern having a hole diameter of 52.25 nm (mJ / cm ² )
E4: Exposure amount when forming a CH pattern with a hole diameter of 57.75 nm (mJ / cm ² )

[Evaluation of in-plane uniformity of pattern dimensions (CDU)]
100 holes in the CH pattern formed by the EOP were observed from above the CH pattern with a length measurement SEM (scanning electron microscope, acceleration voltage 300 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). The hole diameter (nm) of each hole was measured. Then, a triple value (3σ) of the standard deviation (σ) calculated from the measurement result was obtained. The results are shown in Table 8 as “CDU (nm)”.
This “CDU (nm)”, that is, 3σ means that the smaller the value, the higher the dimension (CD) uniformity of a plurality of holes formed in the resist film.

[Evaluation of Circularity]
100 holes in the CH pattern formed by the EOP were observed from above the CH pattern with a length measurement SEM (scanning electron microscope, acceleration voltage 300 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). The distance from the center of each hole to the outer edge was measured in 20 directions. Then, a triple value (3σ) of the standard deviation (σ) calculated from the measurement result was obtained. The results are shown in Table 8 as “roundness (nm)”.
This “roundness (nm)”, that is, 3σ means that the smaller the value, the higher the roundness of the hole.

[Measurement of remaining film ratio]
In the formation of the resist pattern (2) [solvent development process], from the film thickness of the CH pattern formed by the EOP using each resist composition (film thickness of the exposed portion after solvent development: FT2), The residual film ratio (unit:%) was determined by the formula. The results are shown in Table 8.
Residual film rate (%) = (FT2 / FT1) × 100
In the above formula, FT1 represents the resist film thickness (nm) before exposure.
The film thickness was measured with Nanospec 6100A (manufactured by Nanometrics).

  From the results of Table 8, the resist compositions of Examples 47 to 68 to which the present invention is applied have lithography characteristics (EL margin, CDU, Circularity, remaining film ratio) as compared with the resist compositions of Comparative Examples 11 to 15. It was confirmed that it was excellent. In addition, the resist compositions of Examples 47 to 68 were excellent in pattern shape.

Claims (9)

A resist composition that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid,
Containing a base component (A) whose solubility in a developer is changed by the action of an acid,
The resist composition, wherein the substrate component (A) contains 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, 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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). ] The resist composition according to claim 1, wherein the polymer has a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid. The polymer is a lactone-containing cyclic group, -SO 2 _- having a structural unit containing an containing cyclic group or a carbonate-containing cyclic group (a2), the resist composition according to claim 2. The resist composition according to claim 2 or 3 , wherein the polymer has a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group. A step of forming a resist film on a support using the resist composition according to any one of claims 1 to 4 , a step of exposing the resist film, and developing the resist film to form a resist pattern A resist pattern forming method including the step of: The compound represented by the following general formula (I).

[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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). A plurality of R ¹ , Z, X and R ² in the formula may be the same or different. ] A radical polymerization initiator comprising the compound according to claim 6 . It is a manufacturing method of the compound of Claim 6 , Comprising:
The manufacturing method of a compound including the process with which the compound represented by the following general formula (i-1) and the compound represented by the following general formula (i-2) are made to react.

[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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). A plurality of R ¹ , Z and X 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, 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 single bond or a divalent linking group which may contain —O—C (═O) —, —NH—C (═O) — or —NH—C (═NH) —. R ² is a tertiary ester type acid dissociable group having 4 to 20 carbon atoms (excluding a tert-butyl group). ]