JP5743593B2 - Resist composition, resist pattern forming method, and polymer compound - Google Patents

Description

  The present invention relates to a resist composition containing a base material component that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid, a method for forming a resist pattern using the resist composition, and the resist composition The present invention relates to a polymer compound useful as a base material component.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is irradiated with radiation such as light and EB (electron beam) through a mask on which a predetermined pattern is formed. A step of forming a resist pattern having a predetermined shape on the resist film is performed by performing selective exposure and developing.
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. In addition, studies have been made on EUV (extreme ultraviolet), EB, X-rays, etc. having a shorter wavelength (higher energy) than these excimer lasers.

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

At present, as a base resin of a chemically amplified resist composition used in ArF excimer laser lithography and the like, it has a structural unit derived from (meth) acrylic acid ester in its main chain because of its excellent transparency near 193 nm. Resin (acrylic resin) or the like is generally used (see, for example, Patent Document 2). Here, “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position. “(Meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position.
Various acid generators used in chemically amplified resist compositions have been proposed so far, such as onium salt acid generators, oxime sulfonate acid generators, diazomethane acid generators. Nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like are known. Among these, as an onium salt acid generator, an iodonium salt having an iodonium ion as a cation and a sulfonium salt having a sulfonium ion as a cation have been conventionally used. Moreover, as an anion (acid) that forms a salt with the cation, a fluorinated alkyl sulfonate ion is generally used (see, for example, Patent Document 3). Recently, an acid generator having a fluorinated alkyl sulfonate ion having an amide structure and a triphenylsulfonium salt has been proposed (see, for example, Patent Document 4).

  In recent years, a base resin having an acid generating group has been proposed. For example, a resin component having an acid-generating group that generates an acid upon exposure and an acid-decomposable group that changes its polarity by the action of an acid has been proposed in the structure (see, for example, Patent Documents 5 to 7). Such a resin component has both a function as an acid generator and a function as a base material component, and a chemical amplification resist composition can be constituted by only one component. In other words, when the resin component is exposed to light, an acid is generated from the acid-generating group in the structure, the acid-decomposable group is decomposed by the action of the acid, and a polar group such as a carboxy group is generated to increase the polarity. To do. Therefore, if selective exposure is performed on a resin film (resist film) formed using the resin component, the polarity of the exposed portion increases. Therefore, development using an alkaline developer dissolves the exposed portion. And a positive resist pattern is formed.

JP 2008-292975 A JP 2003-241385 A JP 2005-037888 A WO09 / 057769 pamphlet JP-A-10-221852 JP 2006-045311 A JP 2006-215526 A

In the future, there is a demand for new materials that can be used for lithography applications as further advancement of lithography technology and expansion of application fields are expected. For example, as the exposure light source becomes shorter in wavelength (higher energy), a resist material having high sensitivity to electron beams and EUV is required. In addition, as the pattern becomes finer, it is required that a resist pattern can be formed with a good pattern shape.
A resist composition containing a base resin having a structural unit having an acid generating group is said to have improved resolution. However, the conventional proposals still have room for improvement in lithography properties such as resolution, sensitivity, and pattern shape, particularly the pattern shape.
The present invention has been made in view of the above circumstances, and uses a novel polymer compound useful as a base component of a resist composition, a resist composition containing the polymer compound, and the resist composition An object of the present invention is to provide a resist pattern forming method.

A first aspect of the present invention that solves the above problems is a resist composition containing a resin component (A) that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid,
The resin component (A) is a structural unit (a0) containing a group represented by the following general formula (I), and an acrylic acid in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent A structural unit derived from an ester and containing a structural unit (a11) containing an acid-decomposable group whose polarity is increased by the action of an acid, and a hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent A resist composition comprising a polymer compound (A1) having a structural unit (a2 ^S ) that is a structural unit derived from a good acrylate ester and includes a —SO ₂ -containing cyclic group is there.
In a second aspect of the present invention, a resist film is formed on a support using the resist composition of the first aspect , the resist film is exposed, and the resist film is developed to form a resist. a resist pattern forming method comprising forming a pattern.
The third aspect of the present invention is an acrylic resin in which the structural unit (a0) containing a group represented by the following general formula (I) and the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. A structural unit derived from an acid ester and containing a structural unit (a11) containing an acid-decomposable group whose polarity is increased by the action of an acid, and a hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent. a polymeric compound having a structural unit containing an containing cyclic group (a2 ^S) and _- a structural unit which is also derived from an acrylate ester -SO 2.

［式中、Ｒ^１は直鎖状または分岐鎖状のアルキレン基であり、Ｒ^ｆは炭素数１〜４のフッ素化アルキレン基であり、Ｑ^＋は有機カチオンである。］

[Wherein, R ¹ represents a linear or branched alkylene group, R ^f represents a fluorinated alkylene group having 1 to 4 carbon atoms, and Q ⁺ represents an organic cation. ]

In the present specification and claims, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.
The “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group.
“Halogenated alkyl group” is a group in which some or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms. “Halogenated alkylene group” is in which some or all of the hydrogen atoms in the alkylene group are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
A “fluorinated alkyl group” is a group in which some or all of the hydrogen atoms in the alkyl group are substituted with fluorine atoms. A “fluorinated alkylene group” is a group in which some or all of the hydrogen atoms in the alkylene group are substituted with fluorine atoms. Group.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“Acrylic acid ester” is a compound in which the hydrogen atom at the carboxy group terminal of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
In the present specification, 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.
Examples of the substituent bonded to the α-position carbon atom of the α-substituted acrylate ester include a halogen atom, an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxyalkyl group. Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
Examples of the halogen atom as the α-position substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Specific examples of the alkyl group having 1 to 5 carbon atoms as the α-position substituent 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, Examples thereof include linear or branched alkyl groups such as isopentyl group and neopentyl group.
Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms as the α-position substituent 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. Is 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 hydroxyalkyl group as the α-position substituent is preferably a hydroxyalkyl group having 1 to 5 carbon atoms, specifically, a part or all of the hydrogen atoms of the above alkyl group having 1 to 5 carbon atoms. Examples thereof include a group substituted with a hydroxy group.
In the present invention, it is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms that is bonded to the α-position carbon atom of the (α-substituted) acrylate ester. It is more 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 from the viewpoint of industrial availability, it is preferably a hydrogen atom or a methyl group. Most preferred.
“Exposure” is a concept including general irradiation of radiation.

  ADVANTAGE OF THE INVENTION According to this invention, the novel polymer compound useful as a base material component of a resist composition, the resist composition containing this polymer compound, and the resist pattern formation method using this resist composition can be provided.

≪Resist composition≫
The resist composition of the present invention contains a resin component (A) (hereinafter referred to as “component (A)”) that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid. Therefore, it has a property that the solubility in a developing solution is changed by exposure. When a resist film is formed using the resist composition and the resist film is selectively exposed, (A ) Acid is generated from the component, and the acid changes the solubility of the component (A) in the developer. As a result, the solubility of the exposed portion in the developer changes, while the solubility in the unexposed portion does not change in the developer. Therefore, when the resist film is developed, when the resist composition is positive, the exposed portion Is removed by dissolution to form a positive resist pattern. When the resist composition is negative, the unexposed portion is dissolved and 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 a resist composition that forms a negative resist pattern in which an unexposed portion is dissolved and removed. Is referred to as a negative resist composition.
The resist composition of the present invention may be a positive resist composition or a negative resist composition.
In addition, the resist composition of the present invention may be used for an alkali development process using an alkali developer for development processing at the time of forming a resist pattern, and a developer (organic developer) containing an organic solvent is used for the development processing. It may be for the solvent development process used.

<(A) component>
The component (A) is a resin component that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid.
In the present specification, the “resin component” indicates an organic compound having a film forming ability and a polymer. As the resin component, a high molecular compound having a molecular weight of 500 or more, preferably 1000 or more is usually used because a nano-level resist pattern is easily formed. In the case of the resin component, as the “molecular weight”, a mass average molecular weight in terms of polystyrene by GPC (gel permeation chromatography) is used.
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.

When the resist composition of the present invention is a resist composition that forms a negative resist pattern in an alkali development process (or forms a positive resist pattern in a solvent development process), the component (A) is preferably A resin component that generates an acid upon exposure and is soluble in an alkaline developer (hereinafter sometimes referred to as component (A-2)) is used, and a crosslinking agent component is further blended. In such a resist composition, when an acid is generated from the component (A-2) by exposure, the acid acts to cause crosslinking between the component (A-2) and the crosslinking agent component. Solubility decreases (solubility in organic developer increases). Therefore, in the formation of a resist pattern, when a resist film obtained by coating the resist composition on a support is selectively exposed, the exposed portion is hardly soluble in an alkali developer (to an organic developer). On the other hand, the unexposed area remains soluble (almost insoluble in the organic developer) while remaining undissolved in the alkali developer, so that a negative resist pattern can be formed by developing with an alkali developer. . At this time, if an organic developer is used as the developer, a positive resist pattern can be formed.
Examples of the component (A-2) include those in which an acid-generating group that generates an acid upon exposure is introduced into a known resin as a resin that is soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”). .
Examples of the alkali-soluble resin (before introduction of the acid generating group) include α- (hydroxyalkyl) acrylic acid or alkyl of α- (hydroxyalkyl) acrylic acid disclosed in JP-A-2000-206694. A resin having a unit derived from at least one selected from an ester (preferably an alkyl ester having 1 to 5 carbon atoms); disclosed in US Pat. No. 6,949,325, on the α-position carbon atom having a sulfonamide group An acrylic resin or a polycycloolefin resin to which an atom other than a hydrogen atom or a substituent may be bonded; disclosed in US Pat. No. 6,949,325, Japanese Patent Application Laid-Open No. 2005-33645, and Japanese Patent Application Laid-Open No. 2006-317803, Contains a fluorinated alcohol, and the α-position carbon atom is an atom other than a hydrogen atom or Substituent is optionally acrylic resin be bonded; disclosed in Japanese 2006-259582 discloses, polycycloolefin resins having fluorinated alcohol, with minimal swelling can formation of a satisfactory resist pattern.
In addition, the α- (hydroxyalkyl) acrylic acid is an α-position carbon atom to which a carboxy group is bonded among acrylic acids in which an atom other than a hydrogen atom or a substituent may be bonded to the α-position carbon atom. One or both of acrylic acid to which a hydrogen atom is bonded and α-hydroxyalkyl acrylic acid in which a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) is bonded to the α-position carbon atom Show.
As the crosslinking agent component, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, a melamine crosslinking agent, or the like because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent component is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the resist composition of the present invention is a resist composition that forms a positive resist pattern in an alkali development process and a negative resist pattern in a solvent development process, the component (A) is polar due to the action of an acid. Is preferably a resin component (hereinafter sometimes referred to as component (A-1)). Since the polarity of the component (A-1) changes before and after exposure, by using the component (A-1), a good development contrast can be obtained not only in the alkali development process but also in the solvent development process.
That is, when the alkali development process is applied, the component (A-1) is hardly soluble in an alkali developer before exposure, and when acid is generated from the component (A-1) by exposure, the action of the acid This increases the polarity and increases the solubility in an alkaline developer. 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 (A-1) is highly soluble in an organic developer before exposure, and when acid is generated from the component (A-1) by exposure, Due to the action, the polarity becomes higher and the solubility in an organic developer decreases. 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.
In the present invention, the component (A) is preferably the component (A-1). Therefore, the component (A1) is preferably a polymer compound whose polarity is increased by the action of an acid.

[(A1) component]
(Structural unit (a0))
The component (A1) has a structural unit (a0) containing a group represented by the following general formula (I) (hereinafter referred to as group (I)).

［式中、Ｒ^１は直鎖状または分岐鎖状のアルキレン基であり、Ｒ^ｆは炭素数１〜４のフッ素化アルキレン基であり、Ｑ^＋は有機カチオンである。］

[Wherein, R ¹ represents a linear or branched alkylene group, R ^f represents a fluorinated alkylene group having 1 to 4 carbon atoms, and Q ⁺ represents an organic cation. ]

In the formula (I), R ¹ is a linear or branched alkylene group. 1-10 are preferable, as for carbon number of this alkylene group, 1-6 are more preferable, 1-4 are more preferable, and 1 or 2 is especially preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ — and the like. Alkylethylene groups; trimethylene groups (n-propylene groups) [—CH ₂ CH ₂ CH ₂ —]; alkyls such as —CH (CH ₃ ) CH ₂ CH ₂ — and —CH ₂ CH (CH ₃ ) CH ₂ — trimethylene; tetramethylene group _[-CH 2 _CH 2 C _{2 CH 2 -]; - CH} (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; pentamethylene group _[-CH 2 _CH 2 CH ₂ CH ₂ CH ₂ —] and the like.
R ¹ is preferably a linear alkylene group and more preferably a methylene group or an ethylene group because of excellent sensitivity, resolution, pattern shape, and the like.

R ^f is a fluorinated alkylene group having 1 to 4 carbon atoms. The fluorinated alkylene group preferably has 1 to 3 carbon atoms, particularly preferably 1. The fluorinated alkylene group may be either linear or branched, and is preferably linear.
Specific examples of the fluorinated alkylene group include groups in which some or all of the hydrogen atoms of the alkylene group having 1 to 4 carbon atoms are substituted with fluorine atoms among the alkylene groups listed for R ¹ above. It is done.
R ^f is preferably a fluorinated alkylene group in which a carbon atom bonded to an adjacent sulfur atom is fluorinated in terms of acid strength, sensitivity, resolution, pattern shape, and the like. Examples of such fluorinated alkylene _{group, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 _{-, - CF (CF 3)} CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, _{-CF (CF 2 CF 3) CF} 2 -; - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH _{2 CH 2 CF 2 CF 2 -} , - CH 2 CF 2 CF 2 CF 2 - , and the like. Of _{these, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 - or _{-CH 2 CF} 2 _CF 2 - is _{preferable, -CF 2 -, - CF 2} CF 2 - or -CF ₂ CF ₂ CF ₂ - is more preferable, -CF ₂ - is particularly preferred.

Q ⁺ is an organic cation. Q ⁺ is not particularly limited as long as it can form a salt with —SO ₃ ^— in formula (I). For example, Q ⁺ has been conventionally proposed as a cation moiety possessed by an acid generator for a chemically amplified resist. The thing that is.
Q ⁺ is preferably an onium ion. Examples of onium ions include sulfonium ions, iodonium ions, phosphonium ions, diazonium ions, ammonium ions, pyridinium ions, and the like.
Examples of the onium ion include a sulfonium ion represented by the following general formula (Q1) or an iodonium ion represented by the following general formula (Q2). Among these, a sulfonium ion represented by the formula (Q1) is preferable, and at least one of R ¹ ″ to R ³ ″ in the formula is an aryl group which may have a substituent. It is particularly preferable that all of R ¹ ″ to R ³ ″ are aryl groups which may have a substituent.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”はそれぞれ独立に置換基を有していてもよいアリール基、アルキル基又はアルケニル基を表す。式（Ｑ１）におけるＲ^１”〜Ｒ^３”のうち、いずれか二つが相互に結合して式中のイオウ原子と共に環を形成してもよい。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent. Any two of R ¹ ″ to R ³ ″ in formula (Q1) may be bonded to each other to form a ring together with the sulfur atom in the formula. ]

In formula (Q1), R ¹ ″ to R ³ ″ each independently represents an aryl group, alkyl group or alkenyl group which may have a substituent. Any two of R ¹ ″ to R ³ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula.
Moreover, it is preferable that at least one of R ¹ ″ to R ³ ″ is an aryl group, and two or more of R ¹ ″ to R ³ ″ since the lithography characteristics and the resist pattern shape are further improved. Is more preferably an aryl group, and it is particularly preferred that all of R ¹ ″ to R ³ ″ are aryl groups.

As the aryl group for R ¹ ″ to R ³ ″, an unsubstituted aryl group having 6 to 20 carbon atoms; some or all of the hydrogen atoms of the unsubstituted aryl group are alkyl groups, alkoxy groups, halogen atoms, hydroxyl groups , An oxo group (═O), an aryl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, —C (═O) —O—R ⁶ ′, —O—C (═O) —R ⁷ ′, —O And a substituted aryl group substituted with —R ⁸ ′ and the like. R ⁶ ′, R ⁷ ′ and R ⁸ ′ are each a linear, branched or cyclic saturated hydrocarbon group having 1 to 25 carbon atoms, or a C 2 to 5 carbon atoms. It is a linear or branched aliphatic unsaturated hydrocarbon group.
In R ¹ ″ to R ³ ″, the unsubstituted aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group as a substituent in the substituted aryl group of R ¹ ″ to R ³ ″ is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Most preferably.
As the alkoxy group as a substituent in the substituted aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group. Most preferably it is.
The halogen atom as a substituent in the substituted aryl group is preferably a fluorine atom.
Examples of the aryl group as a substituent in the substituted aryl group include the same aryl groups as those described above for R ¹ ″ to R ³ ″, preferably an aryl group having 6 to 20 carbon atoms, and an aryl group having 6 to 10 carbon atoms. Group is more preferable, and phenyl group and naphthyl group are more preferable.

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

As the alkoxycarbonylalkyloxy group in the substituted aryl group, for example,
General formula: —O—R ⁵⁰ —C (═O) —O—R ⁵⁶
[Wherein, R ⁵⁰ represents a linear or branched alkylene group, and R ⁵⁶ represents a tertiary alkyl group. ]
The group represented by these is mentioned.
The linear or branched alkylene group for R ⁵⁰ preferably has 1 to 5 carbon atoms, such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, or a 1,1-dimethylethylene group. Etc.
As the tertiary alkyl group for R ⁵⁶ , 2-methyl-2-adamantyl group, 2-ethyl-2-adamantyl group, 1-methyl-1-cyclopentyl group, 1-ethyl-1-cyclopentyl group, 1-methyl -1-cyclohexyl group, 1-ethyl-1-cyclohexyl group, 1- (1-adamantyl) -1-methylethyl group, 1- (1-adamantyl) -1-methylpropyl group, 1- (1-adamantyl) -1-methylbutyl group, 1- (1-adamantyl) -1-methylpentyl group; 1- (1-cyclopentyl) -1-methylethyl group, 1- (1-cyclopentyl) -1-methylpropyl group, 1- (1-cyclopentyl) -1-methylbutyl group, 1- (1-cyclopentyl) -1-methylpentyl group; 1- (1-cyclohexyl) -1-methylethyl Group, 1- (1-cyclohexyl) -1-methylpropyl group, 1- (1-cyclohexyl) -1-methylbutyl group, 1- (1-cyclohexyl) -1-methylpentyl group, tert-butyl group, tert -Pentyl group, tert-hexyl group and the like.
Moreover, the general ^formula: the ^{R 56} in the -O-R 50 -C (= O ) -O-R 56, also include groups replaced by ^{R 56} '. R ⁵⁶ ′ is a hydrogen atom, an alkyl group, a fluorinated alkyl group, or an aliphatic cyclic group that may contain a hetero atom.
^Examples of the alkyl group for R ⁵⁶ ′ include the same alkyl groups as those described above for R ⁴⁹ .
^Examples of the fluorinated alkyl group for R ⁵⁶ ′ include groups in which some or all of the hydrogen atoms within the alkyl group for R ⁴⁹ have been substituted with fluorine atoms.
Examples of the aliphatic cyclic group which may contain a hetero atom in R ⁵⁶ ′ include an aliphatic cyclic group containing no hetero atom, an aliphatic cyclic group containing a hetero atom in the ring structure, and an aliphatic cyclic group. Examples include those in which a hydrogen atom in the group is substituted with a heteroatom.
Regarding R ⁵⁶ ′, the aliphatic cyclic group containing no hetero atom includes a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, and the like. Can be mentioned. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
Specific examples of the aliphatic cyclic group containing a hetero atom in the ring structure for R ⁵⁶ ′ include groups represented by the following formulas (L1) to (L5) and (S1) to (S4). It is done.
As for R ⁵⁶ ′, the hydrogen atom in the aliphatic cyclic group is specifically substituted with a hetero atom, specifically, the hydrogen atom in the aliphatic cyclic group is substituted with an oxygen atom (═O), etc. Is mentioned.

^{-C (= O) -O-R} 6 ', -O-C (= O) -R 7', 'R 6 ^{in' -O-R 8, R 7} ', R 8' are each carbon atoms 1 to 25 linear, branched or cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a linear or branched aliphatic unsaturated hydrocarbon group having 2 to 5 carbon atoms. .
The saturated hydrocarbon group may be linear, branched or cyclic, or a combination thereof.
1-25 are preferable, as for carbon number of a linear or branched saturated hydrocarbon group, 1-15 are more preferable, and 4-10 are more preferable.
Examples of the linear saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.
The branched saturated hydrocarbon radicals, for example, tertiary alkyl groups mentioned in the description of the R ^56. Examples of branched saturated hydrocarbon groups other than tertiary alkyl groups include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3 -Methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like can be mentioned.
The linear or branched saturated hydrocarbon group may have a substituent. Examples of the substituent include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), a cyano group, and a carboxy group.
As the alkoxy group as a substituent of the linear or branched saturated hydrocarbon group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, An n-butoxy group and a tert-butoxy group are preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent of the linear or branched saturated hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent of the linear or branched saturated hydrocarbon group, part or all of the hydrogen atoms of the linear or branched saturated hydrocarbon group are the halogen atoms. And a group substituted with.
The cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in R ⁶ ′, R ⁷ ′, and R ⁸ ′ may be either a polycyclic group or a monocyclic group. A group in which one hydrogen atom has been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, and the like. More specifically, one hydrogen atom was removed from a monocycloalkane such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Group and the like.
The cyclic saturated hydrocarbon group may have a substituent. For example, part of the carbon atoms constituting the ring of the cyclic alkyl group may be substituted with a heteroatom, or the hydrogen atom bonded to the ring of the cyclic alkyl group may be substituted with a substituent. Good.
Examples of the former include one or more hydrogen atoms from a heterocycloalkane in which a part of the carbon atoms constituting the ring of the monocycloalkane or polycycloalkane is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Examples include groups other than atoms. The ring structure may have an ester bond (—C (═O) —O—). Specifically, a lactone-containing monocyclic group such as a group obtained by removing one hydrogen atom from γ-butyrolactone, or a group obtained by removing one hydrogen atom from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring. And other lactone-containing polycyclic groups.
Examples of the substituent in the latter example include the same as those described above as the substituent that the linear or branched alkyl group may have, a lower alkyl group, and the like.
R ⁶ ′, R ⁷ ′, and R ⁸ ′ may be a combination of a linear or branched alkyl group and a cyclic alkyl group.
A combination of a linear or branched alkyl group and a cyclic alkyl group includes a group in which a cyclic alkyl group is bonded as a substituent to a linear or branched alkyl group (for example, 1- (1-adamantyl). And a group in which a linear or branched alkyl group is bonded to a cyclic alkyl group as a substituent.
Examples of the linear aliphatic unsaturated hydrocarbon group for R ⁶ ′, R ⁷ ′, and R ⁸ ′ include a vinyl group, a propenyl group (allyl group), and a butynyl group.
Examples of the branched aliphatic unsaturated hydrocarbon group for R ⁶ ′, R ⁷ ′, and R ⁸ ′ include a 1-methylpropenyl group and a 2-methylpropenyl group.
The linear or branched aliphatic unsaturated hydrocarbon group may have a substituent. Examples of the substituent include the same ones as those exemplified as the substituent which the linear or branched alkyl group may have.
Among R ⁷ ′ and R ⁸ ′, among them, the lithography characteristics and the resist pattern shape are good, so that the linear or branched saturated hydrocarbon group having 1 to 15 carbon atoms, or the carbon number 3-20 cyclic saturated hydrocarbon groups are preferred.

The aryl groups for R ¹ ″ to R ³ ″ are each preferably a phenyl group or a naphthyl group.
Examples of the alkyl group for R ¹ ″ to R ³ ″ include a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. Especially, it is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
As an alkenyl group of R < ¹ >"-R< ³ >", it is preferable that it is C2-C10, for example, 2-5 are more preferable, and 2-4 are more preferable. Specific examples include a vinyl group, a propenyl group (allyl group), a butynyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.

Any two of R ¹ ″ to R ³ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula. The ring may be saturated or unsaturated. The ring may be monocyclic or polycyclic. For example, when one or both of the two forming a ring is a cyclic group (cyclic alkyl group or aryl group), a polycyclic ring (fused ring) is formed when they are combined.
When two of R ¹ ″ to R ³ ″ are combined to form a ring, one ring containing a sulfur atom in the ring skeleton in the formula is a 3 to 10 membered ring including the sulfur atom. Of these, a 5- to 7-membered ring is particularly preferable.
The ring may have a hetero atom other than the sulfur atom to which R ⁵ and R ⁶ are bonded as an atom constituting the ring skeleton. Examples of the hetero atom include a sulfur atom, an oxygen atom, and a nitrogen atom.
Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydro A thiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.
When any two of R ¹ ″ to R ³ ″ are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one is preferably an aryl group. Examples of the aryl group include the same aryl groups as those described above for R ¹ ″ to R ³ ″.

  Specific examples of the sulfonium ion represented by the formula (Q1) include, for example, triphenylsulfonium, (3,5-dimethylphenyl) diphenylsulfonium, (4- (2-adamantoxymethyloxy) -3,5- Dimethylphenyl) diphenylsulfonium, (4- (2-adamantoxymethyloxy) phenyl) diphenylsulfonium, (4- (tert-butoxycarbonylmethyloxy) phenyl) diphenylsulfonium, (4- (tert-butoxycarbonylmethyloxy)- 3,5-dimethylphenyl) diphenylsulfonium, (4- (2-methyl-2-adamantyloxycarbonylmethyloxy) phenyl) diphenylsulfonium, (4- (2-methyl-2-adamantyloxycarbonylmethyloxy) 3,5-dimethylphenyl) diphenylsulfonium, tri (4-methylphenyl) sulfonium, dimethyl (4-hydroxynaphthyl) sulfonium, monophenyldimethylsulfonium, diphenylmonomethylsulfonium, (4-methylphenyl) diphenylsulfonium, (4-methoxy Phenyl) diphenylsulfonium, tri (4-tert-butyl) phenylsulfonium, diphenyl (1- (4-methoxy) naphthyl) sulfonium, di (1-naphthyl) phenylsulfonium, 1-phenyltetrahydrothiophenium, 1- (4 -Methylphenyl) tetrahydrothiophenium, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium, 1- (4-methoxynaphthalen-1-yl) tetrahydro Rothiophenium, 1- (4-ethoxynaphthalen-1-yl) tetrahydrothiophenium, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium, 1-phenyltetrahydrothiopyranium, 1- (4 -Hydroxyphenyl) tetrahydrothiopyranium, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiopyranium, 1- (4-methylphenyl) tetrahydrothiopyranium and the like.

  Specific examples of the sulfonium ion represented by the formula (Q1) include cation moieties represented by the following formulas (Q1-1-1) to (Q1-1-33). It is done.

［式中、ｇ１は繰返し数を示し、１〜５の整数である。］

[Wherein g1 represents the number of repetitions and is an integer of 1 to 5. ]

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

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

Moreover, among the sulfonium ions represented by the formula (Q1), any two of R ¹ ″ to R ³ ″ are preferably bonded to each other to form a ring together with the sulfur atom in the formula. Specific examples include cation moieties represented by the following formulas (Q1-2) to (Q1-5).

［式中、Ｒ^８１〜Ｒ^８６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_１〜ｎ_５はそれぞれ独立して０〜３の整数であり、ｎ_６は０〜２の整数である。］

[Wherein R ^{81 to} R ⁸⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n _{1 to} n ₅ are each independently an integer of 0 to 3; There, _{n 6} is an integer of 0-2. ]

［式中、Ｒ^９、Ｒ^１０は、それぞれ独立に、置換基を有していてもよいフェニル基、ナフチル基または炭素数１〜５のアルキル基、アルコキシ基、水酸基であり、Ｒ^４’は炭素数１〜５のアルキレン基であり、ｕは１〜３の整数である。］

[Wherein R ⁹ and R ¹⁰ are each independently a phenyl group, a naphthyl group, or an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or a hydroxyl group, which may have a substituent, and R ⁴ ′ is It is a C1-C5 alkylene group, u is an integer of 1-3. ]

In formulas (Q1-2) to (Q1-3), the alkyl group in R ^{81 to} R ⁸⁶ is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a linear or branched alkyl group, A methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n _{1 to} n ₆ attached to R ^{81 to} R ⁸⁶ are integers of 2 or more, the plurality of R ^{81 to} R ⁸⁶ may be the same or different.
n ₁ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.
Preferable examples of the cation represented by the formula (Q1-2) or (Q1-3) include those shown below.

In formulas (Q1-4) to (Q1-5), R ⁹ and R ¹⁰ are each independently a phenyl group, a naphthyl group, an alkyl group having 1 to 5 carbon atoms, an alkoxy group which may have a substituent. Group, hydroxyl group. Examples of the substituent include a substituent in the substituted aryl group exemplified in the description of the aryl group of R ¹ ″ to R ³ ″ (an alkyl group, an alkoxy group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, a halogen atom). Atom, hydroxyl group, oxo group (═O), aryl group, —C (═O) —O—R ⁶ ′, —O—C (═O) —R ⁷ ′, —O—R ⁸ ′, the above general formula ^{: -O-R 50 -C (=} O) based on ^{R 56} is replaced by ^{R 56} 'in the ^{-O-R 56,} etc.) to be similar.
R ⁴ ′ is an alkylene group having 1 to 5 carbon atoms.
u is an integer of 1 to 3, and 1 or 2 is most preferable.
Preferable examples of the cation represented by the formula (Q1-4) or (Q1-5) include those shown below.
In the formula, R ^C represents a substituent (alkyl group, alkoxy group, alkoxyalkyloxy group, alkoxycarbonylalkyloxy group, halogen atom, hydroxyl group, oxo group (═O) exemplified in the description of the substituted aryl group. An aryl group, —C (═O) —O—R ⁶ ′, —O—C (═O) —R ⁷ ′, —O—R ⁸ ′).

In the structural unit (a0), the group (I) is preferably contained in the side chain. In this case, the group (I) may be directly bonded to the carbon atom constituting the main chain, but is preferably bonded via a linking group.
The linking group for linking the carbon atom constituting the main chain and the group (I) is not particularly limited, but a group represented by the following general formula (x1) or (x2) is preferable.
-C (= O) -O-X- (x1)
−A _arl −X ⁰¹ − (x2)
[ _Wherein , X is a divalent linking group, X ⁰¹ is a single bond or a divalent linking group, and A _arl is a divalent aromatic hydrocarbon group which may have a substituent. . ]

In formula (x1), the divalent linking group for X is not particularly limited, but may be a divalent hydrocarbon group which may have a substituent, or a divalent linking group containing a hetero atom. Etc. are mentioned as suitable.
In the divalent hydrocarbon group, “having a substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with a substituent (a group or atom other than a hydrogen atom). To do.
The divalent hydrocarbon group in the linking group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

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

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

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

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

The divalent linking group in X may or may not have an acid-decomposable site in its structure. The “acid-decomposable site” refers to a site where a bond that can be cleaved when an acid generated by exposure (for example, an acid generated from the structural unit (a0)) acts.
Examples of the acid-decomposable site include those having a carbonyloxy group and a tertiary carbon atom bonded to the terminal oxygen atom (—O—). When an acid acts on such an acid dissociable site, the bond between the oxygen atom and the tertiary carbon atom is broken.
When X has such an acid-decomposable part, the acid generated from the group (I) at the time of exposure decomposes the acid-decomposable part in X to increase the polarity. Therefore, even when the component (A1) is composed only of the structural unit (a0), it has a property of increasing the polarity by the action of an acid.

X is particularly preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom.
When X is an alkylene group, the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, It is most preferable that it is 1-3. Specific examples include the same linear alkylene groups and branched alkylene groups as mentioned above.
When X is a divalent alicyclic hydrocarbon group, the alicyclic hydrocarbon group is the same as the alicyclic hydrocarbon group mentioned in the above “aliphatic hydrocarbon group containing a ring in the structure”. Can be mentioned.
The alicyclic hydrocarbon group is particularly preferably a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane or tetracyclododecane.

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

X is preferably a linear or branched alkylene group or a divalent linking group containing a hetero atom, and is a linear or branched alkylene group, the above formula-[Y ²¹ A group represented by —C (═O) —O] _{m ′} —Y ²² — or a group represented by the formula —Y ²¹ —O—C (═O) —Y ²² — is more preferred. A linear or branched alkylene group is particularly preferred.

Wherein (x2), the divalent linking group for X ⁰¹ are the same as those described above X.
_Examples of the divalent aromatic hydrocarbon group in _Aarl include the same aromatic hydrocarbon groups as mentioned for the divalent hydrocarbon group in the description of X.

The structural unit (a0) is preferably a group in which the carbon atom constituting the main chain and the group (I) are linked by the group represented by the general formula (x1) or (x2). It is more preferable that it is connected with a group represented by
That is, the structural unit (a0) is preferably a group in which a group represented by the following general formula (I-1) or (I-2) is bonded to a carbon atom constituting the main chain. It is more preferable that the group represented by 1) is bonded.

［式中、Ｘ、Ｘ^０１、Ａ_ａｒｌ、Ｒ^１、Ｒ^ｆ、Ｑ^＋はそれぞれ前記と同じである。］

[ _Wherein , X, X ⁰¹ , A _arl , R ¹ , R ^f , Q ⁺ are the same as defined above. ]

Specifically, as the structural unit (a0) in which the group represented by the formula (I-1) or (I-2) is bonded to the carbon atom constituting the main chain, a hydrogen atom may be substituted with a substituent The structural unit derived from the vinyl compound which consists of a good vinyl group and group represented by the said general formula (I-1) or (I-2) is mentioned.
The structural unit derived from the vinyl compound means a structural unit formed by cleavage of an ethylenic double bond of the vinyl compound.
The substituent that may substitute the hydrogen atom of the vinyl group of the vinyl compound is not particularly limited as long as it does not correspond to the hydrogen atom and the group represented by the formula (I-1) or (I-2). Examples thereof include a halogen atom, an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a hydroxyalkyl group, and a carboxy group.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Specific examples of the alkyl group having 1 to 5 carbon atoms as the substituent include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, Examples thereof include linear or branched alkyl groups such as a neopentyl group.
Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms as the substituent include groups in which some or all of the hydrogen atoms of the above alkyl group having 1 to 5 carbon atoms have been 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.
The hydroxyalkyl group as the substituent is preferably a hydroxyalkyl group having 1 to 5 carbon atoms. Specifically, a part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms is a hydroxy group. Examples include substituted groups.

As the vinyl compound as described above, for example,
The hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and the hydrogen atom of the carboxy group of acrylic acid is —X—NH—C (═O) —O—R ¹ —R ^f —SO _3. ^- it was replaced with Q ⁺ (alpha-substituted) acrylic acid esters,
A hydrogen atom bonded to the benzene ring of styrene in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, or a part of the hydrogen atom bonded to the benzene ring may be substituted with a substituent Substituted with —X ⁰¹ —NH—C (═O) —O—R ¹ —R ^f —SO ₃ ⁻ Q ⁺ ,
Hydrogen bonded to the naphthalene ring of vinylnaphthalene in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, or a part of the hydrogen atoms bonded to the naphthalene ring may be substituted with a substituent atoms ^{-X 01 -NH-C (= O} ) -O-R 1 -R f -SO 3 - Q + compounds substituted with,
Etc.
Here, “structural unit derived from styrene” means a structural unit formed by cleavage of an ethylenic double bond of styrene, and “structural unit derived from vinylnaphthalene” means vinylnaphthalene. Is a structural unit constituted by cleavage of an ethylenic double bond.
In the present specification, styrene and vinyl naphthalene in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as α-substituted styrene and α-substituted vinyl naphthalene, respectively. Further, styrene and α-substituted styrene may be collectively referred to as (α-substituted) styrene, and vinyl naphthalene and α-substituted vinyl naphthalene may be comprehensively referred to as (α-substituted) vinyl naphthalene.
Examples of the substituent bonded to the α-position carbon atom of α-substituted styrene and α-substituted vinylnaphthalene include those similar to those exemplified as the substituent bonded to the α-position carbon atom of the α-substituted acrylate ester.
Examples of the substituent bonded to the benzene ring of α-substituted styrene or the naphthalene ring of α-substituted vinylnaphthalene include a hydrogen atom and —X ⁰¹ —NH—C (═O) —O—R ¹ —R ^f —SO ₃ ^— Q ^+. If it does not correspond to this, it will not specifically limit, For example, a halogen atom, a C1-C5 alkyl group, a C1-C5 halogenated alkyl group, a hydroxyalkyl group, a hydroxyl group, a carboxy group etc. are mentioned.

  As the structural unit (a0), a structural unit represented by general formula (a0-1) shown below is particularly preferable from the viewpoints of sensitivity, resolution, pattern shape, ease of synthesis, and the like. Especially, the structural unit represented by the following general formula (a0-1-1) is preferable.

［式（ａ０−１）中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｘは２価の連結基であり、Ｒ^１は直鎖状または分岐鎖状のアルキレン基であり、Ｒ^ｆは炭素数１〜４のフッ素化アルキレン基であり、Ｑ^＋は有機カチオンである。式（ａ０−１−１）中、Ｒ、Ｑ^＋はそれぞれ前記と同じであり、ａ”は１〜６の整数であり、ｂ”は１〜４の整数であり、ｃ”は１〜４の整数である。］

[In the formula (a0-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, X is a divalent linking group, and R ¹ is A chain or branched alkylene group, R ^f is a fluorinated alkylene group having 1 to 4 carbon atoms, and Q ⁺ is an organic cation. In formula (a0-1-1), R and Q ⁺ are the same as defined above, a ″ is an integer of 1 to 6, b ″ is an integer of 1 to 4, and c ″ is 1 to 4. Is an integer.]

In formula (a0-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
The alkyl group for R is preferably a linear or branched alkyl group, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, A pentyl group, an isopentyl group, a neopentyl group, etc. are mentioned.
Examples of the halogenated alkyl group for R include groups in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Specific examples of the alkyl group include the same alkyl groups as those described above for R. Examples of the halogen atom that replaces the hydrogen atom of the alkyl group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is more preferable, and a hydrogen atom or a methyl group is most preferable in terms of industrial availability.
Wherein ^{(a0-1), X, R 1} , R f, Q + , respectively, ^X in the formula (I-1) in the same as ^{R 1, R f, Q +} .
In formula (a0-1-1), a ″ is preferably 1 or 2. b ″ is preferably 1 or 2. c ″ is preferably 1 or 2.

The structural unit (a0) contained in the component (A1) may be one type or two or more types.
In the component (A1), the proportion of the structural unit (a0) is preferably 1 to 100 mol%, more preferably 1 to 20 mol%, based on the total of all structural units constituting the component (A1). More preferred is mol%. When the proportion is 1 mol% or more, the sensitivity is improved. In addition, since the structural unit (a0) has the group (I), the polarity is relatively high (for example, compared to the structural unit (a1) described later). Therefore, when the proportion of the structural unit (a0) in the component (A1) is high, the solubility in organic solvents tends to be low, depending on the type of other structural units to be combined. When it is 20 mol% or less, sufficient solubility in a resist solvent (component (S) described later) can be secured.

When the component (A1) is a polymer compound that increases in polarity by the action of an acid, the component (A1) preferably contains an acid-decomposable group that increases in polarity by the action of an acid.
The “acid-decomposable group” is a structure in the structure of the acid-decomposable group by the action of an acid (an acid generated from the structural unit (a0) by exposure or an acid generated from the component (B) described later which is an optional component). It is a group having acid-decomposability capable of cleaving at least a part of the bonds. The acid-decomposable group will be described in detail in the structural unit (a1) described later.
When the structural unit (a0) has an acid-dissociable group (for example, an acid-dissociable moiety as mentioned in the description of X in the formula (x1)), the component (A1) It may be composed of only the unit (a0), and may further have a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid.
When the structural unit (a0) does not include an acid-dissociable group, the component (A1) needs to have a structural unit (a1) in addition to the structural unit (a0).

(Structural unit (a1))
As described above, 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 —O—H in the structure (hereinafter sometimes referred to as OH-containing polar group) is preferable, a carboxy group or a hydroxyl group is preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include a group in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).
The “acid-dissociable group” means that at least a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group is caused by the action of an acid (such as an acid generated from the structural unit (a0) by exposure). It is a group having acid dissociability that can be cleaved. 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. If the alkaline development process is applied due to the increase in polarity, the solubility in an alkaline developer is relatively increased. On the other hand, if the solvent development process is applied, an organic solvent is contained. Solubility in organic developers is reduced.

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

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

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

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

［式中、Ｒ^１４はアルキル基であり、ｇは０〜８の整数である。］

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

［式中、Ｒ^１５およびＲ^１６は、それぞれ独立してアルキル基である。］

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

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

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

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

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

In formula (p1), n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the alkyl group for R ¹ ′ and R ² ′ include the same alkyl groups as those described above for the α-position substituent in the description of the acrylic ester, and a methyl group or an ethyl group is preferable. Is most preferred.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同じである。］

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

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

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

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

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

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

More specifically, the structural unit (a1) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and the acid-decomposable group is The structural unit (a11) containing, derived from hydroxystyrene in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and the hydrogen atom bonded to the benzene ring may be substituted with a substituent A structural unit (a12) in which the hydrogen atom of the hydroxyl group of the structural unit is substituted with an acid-decomposable group or a substituent containing an acid-decomposable group, and the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent The hydrogen atom of the structural unit derived from vinyl (hydroxynaphthalene) optionally substituted with a hydrogen atom bonded to the naphthalene ring may be an acid-decomposable group or an acid-decomposable group. Structural units formed by substituted with an unsubstituted group (a13), and the like. Among these, the structural unit (a11) is preferable.
Here, the “structural unit derived from hydroxystyrene” means a structural unit formed by cleavage of the ethylenic double bond of hydroxystyrene, and “structural unit derived from vinyl (hydroxynaphthalene)”. The term “unit” means a structural unit formed by cleavage of an ethylenic double bond of vinyl (hydroxynaphthalene).
In this specification, hydroxystyrene and vinyl (hydroxynaphthalene) in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as α-substituted hydroxystyrene and α-substituted vinyl (hydroxynaphthalene), respectively. Also, hydroxystyrene and α-substituted hydroxystyrene are included (α-substituted) hydroxystyrene, vinyl (hydroxynaphthalene) and α-substituted vinyl (hydroxynaphthalene) are included (α-substituted) vinyl (hydroxynaphthalene). There is.
Examples of the substituent bonded to the α-position carbon atom of α-substituted hydroxystyrene and α-substituted vinyl (hydroxynaphthalene) are the same as those mentioned as the substituent bonded to the α-position carbon atom of α-substituted styrene. It is done.
Examples of the substituent bonded to the benzene ring of α-substituted hydroxystyrene or the naphthalene ring of α-substituted vinyl (hydroxynaphthalene) are the same as those mentioned as the substituent bonded to the benzene ring of α-substituted styrene.

{Structural unit (a11)}
The structural unit (a11) is a structural unit derived from an (α-substituted) acrylic ester containing an acid-decomposable group whose polarity is increased by the action of an acid.
Examples of the structural unit (a11) include a structural unit represented by the following general formula (a1-0-1), a structural unit represented by the following general formula (a1-0-2), and the like.

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

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

In general formula (a1-0-1), the alkyl group and halogenated alkyl group represented by R are the alkyl group and halogenated alkyl group mentioned as the substituent at the α-position in the description of the α-substituted acrylate ester, respectively. The same thing is mentioned. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group.
X ¹ is not particularly limited as long as it is an acid dissociable group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable groups, acetal type acid dissociable groups, and the like. An ester type acid dissociable group is preferred.
In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).
Examples of the divalent linking group of Y ^2, but are not limited to, divalent hydrocarbon group which may have a substituent group, and a divalent linking group containing a hetero atom as preferred. As the divalent hydrocarbon group which may have these substituents and the divalent linking group containing a hetero atom, in the general formula (a0-1) mentioned in the description of the structural unit (a0), respectively. The same thing as the bivalent coupling group of X of X is mentioned.
The divalent linking group for Y ² is particularly preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom. Among these, a linear or branched alkylene group or a divalent linking group containing a hetero atom is preferable.
Among these, Y ² is preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom, and is linear or branched. Jo alkylene group or more preferably a divalent linking group containing a hetero atom, a linear or branched alkylene group of the formula -Y 21 ^-O-Y 22 ^-, a group represented by the formula - A group represented by [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — or a group represented by the formula —Y ²¹ —O—C (═O) —Y ²² — is more preferable. .

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

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

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

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

  In the present invention, as the structural unit (a11), a structural unit represented by the following general formula (a1-0-11), a structural unit represented by the following general formula (a1-0-12), and the following general formula ( It preferably has at least one selected from the group consisting of a structural unit represented by a1-0-13) and a structural unit represented by the following general formula (a1-0-2). Among these, a structural unit represented by the formula (a1-0-11), a structural unit represented by the following general formula (a1-0-12), and a structure represented by the following general formula (a1-0-2) It is preferable to have at least one selected from the group consisting of units.

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

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

In each formula, the description of R, Y ² and X ² is the same as described above.
In formula (a1-0-11), examples of the alkyl group for R ²¹ include the same alkyl groups as those described above for R ¹⁴ in formulas (1-1) to (1-9). Group or isopropyl group is preferred.
R ²² is, the aliphatic monocyclic group formed together with the carbon atom to which R ²² is bonded, the same aliphatic cyclic groups as those in the aforementioned tertiary alkyl ester-type acid dissociable groups, a monocyclic group The thing similar to what is is mentioned. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably a 3- to 11-membered ring, more preferably a 3- to 8-membered ring, further preferably a 4- to 6-membered ring, and particularly preferably a 5- or 6-membered ring.
In the monocycloalkane, a part of carbon atoms constituting the ring may or may not be substituted with an ether group (—O—).
Moreover, this monocycloalkane may have a C1-C5 alkyl group, a fluorine atom, or a C1-C5 fluorinated alkyl group as a substituent.
Examples of R ²² constituting such an aliphatic monocyclic group include a linear alkylene group in which an ether group (—O—) may be interposed between carbon atoms.

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

［式中、Ｒ、Ｒ^２１はそれぞれ前記と同じであり、ｈは１〜３の整数である。］

[Wherein, R and R ²¹ are the same as defined above, and h is an integer of 1 to 3, respectively. ]

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

In formula (a1-0-13), R and R ²⁴ are the same as defined above.
Examples of the linear alkyl group for R ²⁵ include the same linear alkyl groups as those described above for the alkyl group for R ^{14 in} the formulas (1-1) to (1-9), and methyl Most preferred are groups or ethyl groups.
Specific examples of the structural unit represented by formula (a1-0-13) include formulas (a1-1-1) to (a1-1-3) exemplified as specific examples of general formula (a1-1). ), Structural units represented by (a1-1-7) to (a1-1-15).
As the structural unit represented by the formula (a1-0-13), those in which R ²⁴ is an aliphatic polycyclic group formed together with the carbon atom to which R ²⁴ is bonded are preferably a 2-adamantyl group, The structural unit represented by the formula (a1-1-1) or (a1-1-2) is preferable.

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

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

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

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

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

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

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

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

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

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

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.
In the component (A1), the proportion of the structural unit (a1) is preferably from 15 to 70 mol%, more preferably from 15 to 60 mol%, more preferably from 20 to 55 mol%, based on all the structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when a resist composition is formed, and lithography properties such as sensitivity, resolution, and pattern shape are improved. Moreover, the balance with another structural unit can be taken by making it below an upper limit.
Further, in the component (A1), the ratio (molar ratio) between the structural unit (a0) and the structural unit (a1) is excellent in the effects of the present invention, so the structural unit (a0) :( a1) = 1: 99 to 40:60 is preferable, and 5:95 to 35:65 is more preferable.
In the present invention, it is particularly preferable that the proportion of the structural unit (a0) in the component (A1) is 1 to 20 mol% and the proportion of the structural unit (a1) is 15 to 60 mol%.

(Structural unit (a2))
In addition to the structural units (a0) and (a1), the component (A1) further includes a structural unit derived from an (α-substituted) acrylate ester containing a —SO ₂ -containing cyclic group (hereinafter referred to as a structural unit ( a2 ^S ))) and at least one selected from the group consisting of structural units derived from (α-substituted) acrylic esters containing a lactone-containing cyclic group (hereinafter referred to as structural units (a2 ^L )) It is preferable to have a structural unit (a2).
The —SO ₂ — containing cyclic group or lactone cyclic group of the structural unit (a2) is effective for enhancing the adhesion of the resist film to the substrate when the component (A1) is used for forming the resist film. Is. Moreover, it is effective in the alkali development process in that the affinity with a developer containing water such as an alkali developer is improved.
In addition, when the structural unit (a0) or (a1) includes a —SO ₂ — containing cyclic group or a lactone-containing cyclic group in the structure, the structural unit also corresponds to the structural unit (a2). Such a structural unit corresponds to the structural unit (a0) or (a1) and does not correspond to the structural unit (a2).

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

The —SO ₂ — containing cyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, an oxygen atom (═O), a halogenated alkyl group, a halogenated alkoxy group, a hydroxyalkyl group, —C (═O) —R ⁸⁰ [R. ⁸⁰ is an alkyl group. ], -COOR ⁸¹ [R ⁸¹ is a hydrogen atom or an alkyl group. ^{], - OC (= O)} R 81 [R 81 is a hydrogen atom or an alkyl group. ], A cyano group, an amino group, an amide group, a nitro group, a sulfur atom, a sulfonyl group (SO ₂ ) and the like.
The alkyl group as the substituent may be linear, branched or cyclic, or a combination thereof. The carbon number is preferably 1-30.
When the alkyl group is linear or branched, the carbon number is preferably 1-20, more preferably 1-17, still more preferably 1-15, 10 is particularly preferred. Specifically, the same thing as the specific example of the linear or branched saturated hydrocarbon group illustrated as an aliphatic hydrocarbon group after this is mentioned. Among these, an alkyl group having 1 to 6 carbon atoms is preferable, and 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, and an isopentyl group. Group, neopentyl group, hexyl group and the like. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
When the alkyl group is cyclic (when it is a cycloalkyl group), the carbon number is preferably 3 to 30, more preferably 3 to 20, still more preferably 3 to 15, and 4 to 12 carbon atoms. It is particularly preferred that the number of carbon atoms is 5-10. The alkyl group may be monocyclic or polycyclic. Specific examples include groups in which one or more hydrogen atoms have been removed from monocycloalkane, groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as bicycloalkane, tricycloalkane, and tetracycloalkane. . Specific examples of the monocycloalkane include cyclopentane and cyclohexane. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. In these cycloalkyl groups, some or all of the hydrogen atoms bonded to the ring may or may not be substituted with a substituent such as a fluorine atom or a fluorinated alkyl group.
Examples of the alkoxy group as the substituent include a group bonded to an oxygen atom (—O—) to the alkyl group mentioned as the alkyl group as the substituent.
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 mentioned as the alkyl group as the substituent are substituted with the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.
Examples of the halogenated alkoxy group as the substituent include groups in which part or all of the hydrogen atoms of the alkoxy group exemplified as the alkoxy group as the substituent are substituted with the halogen atom. The halogenated alkoxy group is preferably a fluorinated alkoxy group.
Examples of the hydroxyalkyl group as the substituent include a group in which at least one hydrogen atom of the alkyl group mentioned as the alkyl group as the substituent is substituted with a hydroxyl group. 1-3 are preferable and, as for the number of the hydroxyl groups which a hydroxyalkyl group has, 1 is the most preferable.
In —C (═O) —R ⁸⁰ , —COOR ⁸¹ , —OC (═O) R ⁸¹ as the substituent, the alkyl group in R ⁸⁰ and R ⁸¹ is exemplified as the alkyl group as the substituent. The thing similar to an alkyl group is mentioned.
Among the above-mentioned substituents of the —SO ₂ -containing cyclic group, an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, an oxygen atom (═O), a halogenated alkyl group, a hydroxyalkyl group, —COOR ⁸¹ , —OC (═O) R ⁸¹ , a cyano group and the like are preferable.

More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by the following general formulas (3-1) to (3-4).

［式中、Ａ’は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり、ｚは０〜２の整数であり、Ｒ^８はアルキル基、アルコキシ基、ハロゲン原子、水酸基、酸素原子（＝Ｏ）、ハロゲン化アルキル基、ヒドロキシアルキル基、−ＣＯＯＲ^８１、−ＯＣ（＝Ｏ）Ｒ^８１またはシアノ基であり、Ｒ^８１は水素原子またはアルキル基である。］

[Wherein, A ′ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, z is an integer of 0 to 2, and R ⁸ is an alkyl group. , An alkoxy group, a halogen atom, a hydroxyl group, an oxygen atom (═O), a halogenated alkyl group, a hydroxyalkyl group, —COOR ⁸¹ , —OC (═O) R ⁸¹ or a cyano group, and R ⁸¹ is a hydrogen atom or an alkyl group It is a group. ]

In the general formulas (3-1) to (3-4), A ′ represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (—O—) or a sulfur atom (—S—), An oxygen atom or a sulfur atom.
The alkylene group having 1 to 5 carbon atoms in A ′ is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
A ′ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
z may be any of 0 to 2, and is most preferably 0.
When z is 2, the plurality of R ⁸ may be the same or different.
The alkyl group in R ^8, an alkoxy group, a halogen atom, a halogenated alkyl group, hydroxyalkyl ^group, the ^{-COOR 81, -OC (= O)} R 81, respectively, the -SO ₂ at - containing cyclic group is Yes And the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ⁸¹ , —OC (═O) R ⁸¹ , and hydroxyalkyl groups as those which may be substituted.
Below, the specific cyclic group represented by the said general formula (3-1)-(3-4) is illustrated. “Ac” in each formula represents an acetyl group.

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

More specifically, examples of the structural unit (a2 ^S ) include structural units represented by general formula (a2-6) shown below.

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

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

In formula (a2-6), R is the same as R in general formula (a1-0-1) or (a1-0-2) mentioned in the description of structural unit (a1).
R ^S is the same as the —SO ₂ — containing cyclic group mentioned above.
R ²⁹ may be a single bond or a divalent linking group. Since it is excellent in the effect of this invention, it is preferable that it is a bivalent coupling group.
The divalent linking group for R ²⁹ is not particularly limited, and examples thereof include the divalent linking group for Y ² in the general formula (a1-0-2) in the description of the structural unit (a1). The thing similar to a thing is mentioned.
As the divalent linking group for R ²⁹ , an alkylene group or an ester bond (—C (═O) —O—) is particularly preferable.
The alkylene group is preferably a linear or branched alkylene group. Specifically, the same as the linear alkylene group and the branched alkylene group mentioned as the aliphatic hydrocarbon group for Y ² can be used.
As the divalent linking group containing an ester bond, in particular, the general formula: —L ⁴ —C (═O) —O— [wherein L ⁴ is a divalent linking group. ] Is preferable. That is, the structural unit (a2 ^S ) is preferably a structural unit represented by the following general formula (a2-6-1).

［式中、ＲおよびＲ^Ｓはそれぞれ前記と同様であり、Ｌ^４は２価の連結基である。］

[Wherein, R and R ^S are the same as defined above, and L ⁴ represents a divalent linking group. ]

L ⁴ is not particularly limited, and examples thereof include those similar to those exemplified as the divalent linking group for Y ² in the general formula (a1-0-2) in the description of the structural unit (a1). Can be mentioned.
The divalent linking group for L ⁴ is preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom.
Examples of the linear or branched alkylene group, divalent alicyclic hydrocarbon group, and divalent linking group containing a hetero atom include the linear or branched groups mentioned above as preferred for Y ^2. Examples thereof include the same chain alkylene groups, divalent alicyclic hydrocarbon groups, and divalent linking groups containing a hetero atom.
Among these, a linear or branched alkylene group or a divalent linking group containing an oxygen atom as a hetero atom is preferable.
The linear or branched alkylene group for L ⁴ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 5 carbon atoms. As the linear alkylene group, a methylene group or an ethylene group is preferable, and a methylene group is particularly preferable. As the branched alkylene group, an alkylmethylene group or an alkylethylene group is preferable, and —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — or —C (CH ₃ ) ₂ CH ₂ — is particularly preferable.
As the divalent linking group containing an oxygen atom, a divalent linking group containing an ether bond or an ester bond is preferable, and the general formula − shown in the description of Y ^{2 in} the general formula (a1-0-2) is used. Y ²¹ —O—Y ²² —, —Y ²¹ —O—C (═O) —Y ²² — or — [Y ²¹ —C (═O) —O] _m —Y ²² — is more preferred. preferable. Of these, a group represented by the formula —Y ²¹ —O—C (═O) —Y ²² — is preferable, and represented by — (CH ₂ ) _c —C (═O) —O— (CH ₂ ) _d —. Particularly preferred are the groups c is an integer of 1 to 5, and 1 or 2 is preferable. d is an integer of 1-5, and 1 or 2 is preferable.

As the structural unit (a2 ^S ), a structural unit represented by general formula (a2-6-11) or (a2-6-12) shown below is particularly desirable, and represented by formula (a2-6-12) A structural unit is more preferable.

［式中、Ｒ、Ａ’、Ｒ^８、ｚおよびＬ^４はそれぞれ前記と同じである。］

[Wherein, R, A ′, R ⁸ , z and L ⁴ are the same as defined above. ]

In formula (a2-6-11), A ′ is preferably a methylene group, an oxygen atom (—O—) or a sulfur atom (—S—).
L ⁴ is preferably a linear or branched alkylene group or a divalent linking group containing an oxygen atom. As the linear or branched alkylene group and the divalent linking group containing an oxygen atom in L ^4, the linear or branched alkylene group and the divalent linking group containing an oxygen atom, respectively, mentioned above are used. Examples are the same as the linking group.
As the structural unit represented by the formula (a2-6-12), a structural unit represented by general formula (a2-6-12a) or (a2-6-12b) shown below is particularly desirable.

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

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

-Structural unit (a2 ^L ):
The structural unit (a2 ^L ) is a structural unit derived from an (α-substituted) acrylic ester containing a lactone-containing cyclic group.
A lactone containing cyclic group shows the cyclic group containing one ring (lactone ring) containing a -O-C (O)-structure as above-mentioned. 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 cyclic group in the structural unit (a2 ^L ) is not particularly limited, and any one can be used. Specifically, the lactone-containing monocyclic group is a group obtained by removing one hydrogen atom from a 4- to 6-membered ring lactone, such as a group obtained by removing one hydrogen atom from β-propionolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed and a group in which one hydrogen atom has been removed from δ-valerolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
The lactone cyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, an oxygen atom (═O), a halogenated alkyl group, a halogenated alkoxy group, a hydroxyalkyl group, —C (═O) —R ⁸⁰ [R. ⁸⁰ is an alkyl group. ], -COOR ⁸¹ [R ⁸¹ is a hydrogen atom or an alkyl group. ^{], - OC (= O)} R 81 [R 81 is a hydrogen atom or an alkyl group. ], A cyano group, an amino group, an amide group, a nitro group, a sulfur atom, a sulfonyl group (SO ₂ ) and the like.
Among these, as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a halogenated alkoxy group, a hydroxyalkyl group, —C (═O) —R ⁸⁰ , —COOR ⁸¹ , —OC (═O) R ⁸¹ Are the same as those described above as the substituent that the —SO ₂ -containing cyclic group may have.
As the substituent of the lactone cyclic group, in particular, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or —COOR ″ [R ″ is a hydrogen atom or an alkyl group. ] Is preferable. The alkyl group, alkoxy group, and —COOR ″ are the same as the alkyl group, alkoxy group, and —COOR ″ mentioned in the description of R ′ in the following general formulas (a2-1) to (a2-5), respectively. Things.

Examples of the structural unit (a2 ^L ) include, for example, those obtained by substituting R ^S in the general formula (a2-6) with a lactone-containing cyclic group, and more specifically, the following general formula (a2-1) ) To (a2-5).

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

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ′ is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, carbon The alkoxy group of number 1-5 or -COOR "[R" is a hydrogen atom or an alkyl group. R ²⁹ is a single bond or a divalent linking group, s ″ is an integer of 0 to 2; A ″ is an alkylene of 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom. A group, an oxygen atom or a sulfur atom; m is 0 or 1; ]

R in the general formulas (a2-1) to (a2-5) is the same as R in the general formula (a1-0-1) or (a1-0-2) mentioned in the description of the structural unit (a1). Can be mentioned.
Examples of the alkyl group having 1 to 5 carbon atoms of R ′ include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group.
Examples of the alkoxy group having 1 to 5 carbon atoms of R ′ include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group.
R ′ is preferably a hydrogen atom in view of industrial availability.
The alkyl group in R ″ may be linear, branched or cyclic.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Or a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group Specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Etc.
A ″ is preferably an alkylene group having 1 to 5 carbon atoms, an oxygen atom (—O—) or a sulfur atom (—S—), more preferably an alkylene group having 1 to 5 carbon atoms or —O—. The alkylene group having 1 to 5 carbon atoms is more preferably a methylene group or dimethylmethylene group, and most preferably a methylene group.
R ²⁹ is the same as ^{R 29} in the general formula (a2-6).
In formula (a2-1), s ″ is preferably 1 to 2.
Specific examples of the structural units represented by the general formulas (a2-1) to (a2-5) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group, respectively.

The structural unit (a2) contained in the component (A1) may be one type or two or more types. For example, as the structural unit (a2), only the structural unit (a2 ^S ) may be used, or only the structural unit (a2 ^L ) may be used, or they may be used in combination. As the structural unit (a2 ^S ) or the structural unit (a2 ^L ), one type may be used alone, or two or more types may be used in combination.
As the structural unit (a2), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-6) is preferable, and the general formulas (a2-1) to ( At least one selected from the group consisting of structural units represented by a2-3) and (a2-6) is more preferred. Among them, chemical formulas (a2-1-1), (a2-2-1), (a2-2-7), (a2-3-1), (a2-3-5) or (a2-6-1) And at least one selected from the group consisting of structural units represented by
The proportion of the structural unit (a2) in the component (A1) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, with respect to the total of all structural units constituting the component (A1). 50 mol% is more preferable. By making it the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by making it the upper limit value or less, it is possible to balance with other structural units.

(Structural unit (a3))
The component (A1) may further have a structural unit (a3) derived from an (α-substituted) acrylate ester containing a polar group-containing hydrocarbon group as long as the effects of the present invention are not impaired. When the component (A1) has the structural unit (a3), the polarity of the component (A1) after exposure is further improved. The improvement in polarity contributes to an improvement in resolution and the like, particularly in the case of an alkali development process.
The polar group-containing hydrocarbon group is a hydrocarbon group to which a polar group is bonded.
As the preferred polar group in the structural unit (a3), a hydroxyl group, a cyano group, a carboxy group, a hydroxyalkyl group, a hydroxyalkyloxy group, a fluorinated alcohol group (a part or all of hydrogen atoms bonded to carbon atoms are fluorine atoms). Substituted hydroxyalkyl group) and the like.
The carbon chain in the hydroxyalkyl group, hydroxyalkyloxy group and fluorinated alcohol group may be linear, branched or cyclic, or a combination thereof. As for carbon number of this carbon chain, 1-10 are preferred.
Among the above, as the polar group, a hydroxyl group is preferable.
In the structural unit (a3), the number of polar groups bonded to the hydrocarbon group is not particularly limited, but is preferably 1 to 3, and most preferably 1.
The hydrocarbon group to which the polar group is bonded may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. That is, the polar group-containing hydrocarbon group may be a polar group-containing aliphatic hydrocarbon group or a polar group-containing aromatic hydrocarbon group.

In the polar group-containing aliphatic hydrocarbon group, the aliphatic hydrocarbon group to which the polar group is bonded may be saturated, unsaturated, or saturated.
More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.
The linear or branched aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, more preferably 1 to 10, more preferably 1 to 8, and still more preferably 1 to 6.
In the linear or branched aliphatic hydrocarbon group, part or all of the hydrogen atoms may be substituted with a substituent other than the polar group. 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. Further, the linear or branched aliphatic hydrocarbon group may have a divalent group containing a hetero atom between carbon atoms. The “divalent group containing a heteroatom” is the “divalent linking group containing a heteroatom” exemplified for Y ² in the general formula (a1-0-2) in the description of the structural unit (a1). And the like.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group, the cyclic aliphatic hydrocarbon group bonded to the terminal of the chain aliphatic hydrocarbon group described above, or a chain. And a group intervening in the middle of the aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 30 carbon atoms. The cyclic aliphatic hydrocarbon group may be polycyclic, monocyclic, or polycyclic.
As the cyclic aliphatic hydrocarbon group, specifically, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from those proposed. For example, the monocyclic aliphatic hydrocarbon group is preferably a group in which two or more hydrogen atoms are removed from a monocycloalkane having 3 to 20 carbon atoms, and examples of the monocycloalkane include cyclopentane and cyclohexane. . As the polycyclic aliphatic hydrocarbon group, a group in which two or more hydrogen atoms have been removed from a polycycloalkane having 7 to 30 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane. , Tricyclodecane, tetracyclododecane and the like.
In the cyclic aliphatic hydrocarbon group, part or all of the hydrogen atoms may be substituted with a substituent other than the polar group. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

When the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched aliphatic hydrocarbon group, the structural unit (a3) is a structural unit derived from a hydroxyalkyl ester of acrylic acid. Is preferred. The hydroxyalkyl group in the structural unit is preferably a hydroxyalkyl group having 1 to 10 carbon atoms.
When the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is an aliphatic hydrocarbon group containing a ring in the structure, the structural unit (a3) includes 1 to 3 hydroxyl groups, a cyano group, or a hydroxy group. Those having an adamantyl group or norbornyl group to which an alkyl group is bonded (for example, structural units represented by general formulas (a3-1) to (a3-3) described later) are preferable.

Examples of the aromatic hydrocarbon group to which the polar group is bonded in the polar group-containing aromatic hydrocarbon group include a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and phenanthryl. A divalent aromatic hydrocarbon group obtained by removing one hydrogen atom from the nucleus of the aromatic hydrocarbon of a monovalent aromatic hydrocarbon group, such as a group;
An aromatic hydrocarbon group in which a part of carbon atoms constituting the ring of the divalent aromatic hydrocarbon group is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom;
A benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, an 1-naphthylethyl group, an arylalkyl group such as a 2-naphthylethyl group, etc., and a hydrogen atom from the nucleus of the aromatic hydrocarbon Further, an aromatic hydrocarbon group from which one is removed;
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).

  As the structural unit (a3), structural units represented by general formulas (a3-1) to (a3-11) shown below are preferable.

［式中、Ｒは前記と同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数であり、ｑ、ｒ”、ｖ”、ｗ”はそれぞれ独立に１〜３の整数である。］

[Wherein, R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t ′ is an integer of 1 to 3, and l is an integer of 1 to 5] S is an integer of 1 to 3, and q, r ″, v ″, and w ″ are each independently an integer of 1 to 3.]

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group.
In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-4), q is preferably 1 or 2, and more preferably 1. When q is 2, it is preferable that the cyano group is bonded to the 3rd and 5th positions of the adamantyl group. When q is 1, it is preferable that the cyano group is bonded to the 3-position of the adamantyl group.
In formula (a3-8), r ″ is preferably 1 or 2, and more preferably 1.
In formula (a3-9), v ″ is preferably 1 or 2, and more preferably 1.
In formula (a3-10), w ″ is preferably 1 or 2, and more preferably 1.

The structural unit (a3) contained in the component (A1) may be one type or two or more types.
When the structural unit (a3) is contained, the proportion of the structural unit (a3) in the component (A1) is preferably 1 to 40 mol% with respect to the total of all structural units constituting the component (A1). -30 mol% is more preferable, and 5-20 mol% is further more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

The component (A1) may contain other structural units other than the structural units (a0) to (a3) as long as the effects of the present invention are not impaired.
The other structural unit is not particularly limited as long as it is another structural unit that is not classified into the above structural units (a0) to (a3). For ArF excimer laser, for KrF excimer laser (preferably ArF excimer) A number of hitherto known materials can be used for resist resins such as lasers.
Examples of the other structural unit include a structural unit (a4) derived from an (α-substituted) acrylate ester containing an acid non-dissociable aliphatic polycyclic group, and a configuration derived from (α-substituted) styrene. Examples of the unit include structural units derived from (α-substituted) vinylnaphthalene.

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

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

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

［式中、Ｒは前記と同じである。］

[Wherein, R 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 structural unit (a4) is contained, the proportion of the structural unit (a4) in the component (A1) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1). -20 mol% is more preferable, and 5-20 mol% is further more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a4) can be sufficiently obtained, and by setting the upper limit value or less, it is possible to balance with other structural units.

In the present invention, the component (A1) is preferably a copolymer having the structural units (a0) and (a1), and is a copolymer having the structural units (a0), (a1) and (a2). More preferred is a copolymer having structural units (a0), (a1), (a2) and (a3).
Examples of the copolymer having the structural units (a0) and (a1) include, for example, a copolymer composed of the structural units (a0) and (a1), and a structural unit (a0), (a1), and (a2). Copolymer, copolymer composed of structural units (a0), (a1) and (a3), copolymer composed of structural units (a0), (a1), (a2) and (a3), structural unit (a0 ), (A1), (a2), (a3) and a copolymer comprising (a4).

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

The component (A1) can be obtained by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN).
Further, for the component (A1), in the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that the terminal A —C (CF ₃ ) ₂ —OH group may be introduced into the. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing
A commercially available monomer may be used as the monomer for deriving each structural unit, or the monomer may be synthesized using a known method. For example, the monomer for deriving the structural unit (a0) can be produced according to the method disclosed in paragraphs [0115] to [0118] of International Publication No. 2009/057769.

In the component (A), as the component (A1), one type may be used alone, or two or more types may be used in combination.
The proportion of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass, further preferably 75% by mass, and 100% by mass with respect to the total mass of the component (A). May be. When the ratio is 25% by mass or more, effects such as lithography characteristics are improved.
The component (A) is a resin component (hereinafter referred to as (A2)) that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid other than the component (A1) within a range not impairing the effects of the present invention May be included). The component (A2) is not particularly limited, and conventionally proposed components can be used.
In the resist composition of the present invention, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<Optional component>
The resist composition of the present invention may further contain an acid generator component (B) that does not correspond to the component (A) and generates an acid upon exposure (hereinafter referred to as the 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, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”はそれぞれ独立に置換基を有していてもよいアリール基、アルキル基又はアルケニル基を表す。式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか二つが相互に結合して式中のイオウ原子と共に環を形成してもよい。Ｒ^４”は、置換基を有していてもよいアルキル基、ハロゲン化アルキル基、アリール基、またはアルケニル基を表す。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent. Any two of R ¹ ″ to R ³ ″ in formula (b-1) may be bonded to each other to form a ring together with the sulfur atom in the formula. R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.

Wherein ^{(b-1), R 1} "~R 3" is the same as ^R 1 ^{"~R 3"} in the general formula (Q1) in listed in Q + DESCRIPTION In the general formula (I), ^R 5 ^{"~R 6"} in formula (b-2) is the same as ^R 5 ^{"~R 6"} in the general formula (Q2).
In the formula (b-1), R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.
The alkyl group for R ⁴ ″ may be linear, branched or cyclic.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
Examples of the halogenated alkyl group for R ⁴ ″ include groups in which part or all of the hydrogen atoms of the linear, branched, or cyclic alkyl group have been substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. 50 to 100% is preferable, and 100% is most preferable. The higher the halogenation rate, the better the acid strength.
The aryl group for R ⁴ ″ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group in R ⁴ ″ is preferably an alkenyl group having 2 to 10 carbon atoms.
In the above R ⁴ ″, “may have a substituent” means that a part or all of the hydrogen atoms in the alkyl group, halogenated alkyl group, aryl group, or alkenyl group are a substituent (hydrogen atom). It may be substituted with other atoms or groups).
The number of substituents in R ⁴ ″ may be one, or two or more.

Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, a formula: X ¹⁰ -Q ^1- [wherein Q ¹ is a divalent linking group containing an oxygen atom, and X ¹⁰ represents a substituent. It is a C3-C30 hydrocarbon group which may have. ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described as the halogen atom and alkyl group in the halogenated alkyl group in R ⁴ ″.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

In the group represented by X ¹⁰ -Q ^1- , Q ¹ is a divalent linking group containing an oxygen atom.
Q ¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond; —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —O—C (═O) — , R ^{91 to} R ⁹³ are each independently an alkylene group.), —X ⁰² —NH—C (═O) —O—R ¹ — and the like.
The alkylene group for R ^{91 to} R ⁹³ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ — and the like. Alkylethylene groups; trimethylene groups (n-propylene groups) [—CH ₂ CH ₂ CH ₂ —]; alkyls such as —CH (CH ₃ ) CH ₂ CH ₂ — and —CH ₂ CH (CH ₃ ) CH ₂ — trimethylene; tetramethylene group _[-CH 2 _CH 2 C _{2 CH 2 -]; - CH} (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; pentamethylene group _[-CH 2 _CH 2 CH ₂ CH ₂ CH ₂ —] and the like.
Q ¹ is preferably a divalent linking group containing an ester bond or an ether bond, and in particular, —R ⁹¹ —O—, —R ⁹² —O—C (═O) — or —C (═O) — O—R ⁹³ —O—C (═O) — is preferred.
^{-X 02 -NH-C (= O} ) -O-R 1 - R 1 in is the same as ^{R 1} in the formula (I). ^X02 is a single bond or a divalent linking group, and examples of the linking group include those similar to X in the formula (I).

In the group represented by X ¹⁰ -Q ^1- , the hydrocarbon group for X ¹⁰ may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic hydrocarbon group include a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Aryl groups such as aryl group, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., from which one is removed. The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be.
Examples of the former include heteroaryl groups in which some of the carbon atoms constituting the ring of the aryl group are substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and aromatic hydrocarbons in the arylalkyl groups. Examples include heteroarylalkyl groups in which some of the carbon atoms constituting the ring are substituted with the above heteroatoms.
Examples of the substituent of the aromatic hydrocarbon group in the latter example include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent of the aromatic hydrocarbon group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The aliphatic hydrocarbon group for X ¹⁰ may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In X ¹⁰ , the aliphatic hydrocarbon group may be a group in which a part of carbon atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom, and hydrogen constituting the aliphatic hydrocarbon group A part or all of the atoms may be substituted with a substituent containing a hetero atom.
The “heteroatom” in X ¹⁰ is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. —, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, — S (= O) ₂ —O— and the like can be mentioned. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

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

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

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

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

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

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

Among the above, X ¹⁰ is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. Examples of the polycyclic aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from the polycycloalkane, groups represented by the above (L2) to (L5) and (S3) to (S4). Etc. are preferred.

Further, X ¹⁰ is particularly preferably one having a polar site because the lithography characteristics and the resist pattern shape are further improved.
As having a polar moiety, for example, substituted groups in which some of the carbon atoms constituting the aliphatic cyclic group for X ¹⁰ described above contains a hetero atom, i.e., -O -, - C (= O) -O -, -C (= O)-, -O-C (= O) -O-, -C (= O) -NH-, -NH- (H is substituted with a substituent such as an alkyl group or an acyl group. may _{be), - S -, - S} (= O) 2 -, - S (= O) 2 -O- , etc., in include those substituted.

Among the above, R ⁴ ″ preferably has X ¹⁰ -Q ^1- as a substituent. In this case, R ⁴ ″ has X ¹⁰ -Q ¹ -Y ^1- [wherein Q ¹ and X ¹⁰ is the same as above, and Y ¹ is an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. is there. ] Is preferable.
In the group represented by X ¹⁰ -Q ¹ -Y ^1- , examples of the alkylene group for Y ¹ include the same alkylene groups as those described above for Q ¹ having 1 to 4 carbon atoms.
Examples of the fluorinated alkylene group for Y ¹ include groups in which some or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^1, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH _{(CH 3) -, - C} (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

Y ¹ is preferably a fluorinated alkylene group, and particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the adjacent sulfur atom is fluorinated. Examples of such fluorinated alkylene _{group, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 _{-, - CF (CF 3)} CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, _{-CF (CF 2 CF 3) CF} 2 -; - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH ₂ CH ₂ CF ₂ CF ₂ —, —CH ₂ CF ₂ CF ₂ CF ₂ — and the like can be mentioned.
Of _{these, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, or _CH 2 _CF 2 CF ₂ - is _{preferable, -CF 2 -, - CF 2} CF 2 - or -CF ₂ CF ₂ CF ₂ - is more preferable, -CF ₂ - is particularly preferred.

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

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group, alkyl group or alkenyl group which may have a substituent.
Moreover, it is preferable that at least one of R ⁵ ″ to R ⁶ ″ is an aryl group because lithography characteristics and the resist pattern shape are further improved, and any of R ⁵ ″ to R ⁶ ″ is an aryl group. More preferably.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Examples of the alkenyl group for R ⁵ ″ to R ⁶ ″ include the same alkenyl groups for R ¹ ″ to R ³ ″.
Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
Specific examples of the cation moiety in the compound represented by the formula (b-2) include diphenyliodonium and bis (4-tert-butylphenyl) iodonium.
"The, ^{R 4} in the above formula (b-1)" ^{R 4} in the formula (b-2) include the same as.

  Specific examples of the onium salt acid generator represented by the formula (b-1) or (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, and its hepta Fluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutane Sulfonate, trifluoromethanesulfonate of (4-methylphenyl) diphenylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, trifluoromethane sulfonate of (4-methoxyphenyl) diphenylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane Sulfonate, tri (4-tert-butyl) phenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutanesulfonate, diphenyl (1- (4-methoxy) naphthyl) sulfonium trifluoromethanesulfonate, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenyl sulphonium trifluoromethane sulphonate, its heptafluoropropane sulphonate or its nonafluorobutane sulphonate; 1-phenyltetrahydrothiophenium trifluoromethane sulphonate, its heptafluoropropane sulphonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenol Nyl) tetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate; 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-ethoxynaphthalene-1 -Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nona 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethane Sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5- Dimethyl-4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropan Sulfonate or nonafluorobutane sulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.

  In addition, the anion portion of these onium salts may be substituted with alkyl sulfonates such as methane sulfonate, n-propane sulfonate, n-butane sulfonate, n-octane sulfonate, 1-adamantane sulfonate, and 2-norbornane sulfonate; d-camphor-10-sulfonate Substituted alkyl sulfonates such as benzene salts, onium salts substituted with aromatic sulfonates such as perfluorobenzene sulfonate and p-toluene sulfonate can also be used.

  Moreover, the onium salt which replaced the anion part of these onium salts by the anion represented by either of following formula (b1)-(b8) can also be used.

［式中、ｙは１〜３の整数であり、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｔ３は１〜３の整数であり、ｒ１〜ｒ２はそれぞれ独立に０〜３の整数であり、ｉは１〜２０の整数であり、Ｒ^５０は置換基であり、ｍ１〜ｍ５はそれぞれ独立に０または１であり、ｖ０〜ｖ５はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ５はそれぞれ独立に０〜３の整数であり、Ｑ”は前記と同じである。］

[Wherein y is an integer of 1 to 3, q1 and q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 ~ R2 is each independently an integer of 0 to 3, i is an integer of 1 to 20, R ⁵⁰ is a substituent, m1 to m5 are each independently 0 or 1, and v0 to v5 are each Each independently represents an integer of 0 to 3, w1 to w5 are each independently an integer of 0 to 3, and Q ″ is the same as defined above.]

Examples of the substituent for R ⁵⁰ are the same as those described above as the substituent that the aliphatic hydrocarbon group may have and the substituent that the aromatic hydrocarbon group may have in X ¹⁰ above. Is mentioned.
Code (r1 and r2, w1 to w5) attached to R ⁵⁰ when it is 2 or more integer, a plurality of ^{R 50} in the compound may be the same, respectively, it may be different.

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

［式中、Ｘ^１０、Ｘ^０２、Ｒ^１、Ｒ^ｆ、Ｑ^＋はそれぞれ前記と同じである。］

[Wherein, X ¹⁰ , X ⁰² , R ¹ , R ^f and Q ⁺ are the same as defined above. ]

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

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

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

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

As the onium salt-based acid generator, in the general formula (b-1) or (b-2), anion ^{- a, R a -COO (R 4 "} SO 3) - [ wherein, ^{R a} Is an alkyl group or a fluorinated alkyl group.] An onium salt-based acid generator substituted with a cation moiety can also be used (the cation moiety is the same as the cation moiety in the formula (b-1) or (b-2)).
In the above formula, as R ^{a, the same} as R ⁴ ″ can be mentioned.
Specific examples of the “R ^a —COO ⁻ ” include trifluoroacetate ions, acetate ions, 1-adamantanecarboxylate ions and the like.

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

（式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

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

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

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

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

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

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

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

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

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

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

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

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

<Other optional components>
The resist composition of the present invention does not fall under the component (A) as long as the effects of the present invention are not impaired, and is a base material component (hereinafter referred to as (C) component) whose solubility in a developing solution is changed by the action of an acid. .) May be contained.
The “base component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
Organic compounds 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, a nonpolymer having a molecular weight of 500 or more and less than 4000 is referred to as a low molecular compound.
As the polymer, a resin having a molecular weight of 1000 or more is usually used.
The component (C) may be a base component whose solubility in a developer increases due to the action of an acid, or a base component whose solubility in a developer decreases due to the action of an acid. In the case where the component A) has increased solubility in the developer due to the action of the acid, a component whose solubility in the developer is increased due to the action of the acid is used. In the case where the solubility in the developing solution is reduced, the one in which the solubility in the developing solution is reduced by the action of an acid is used.
The component (C) is not particularly limited, and can be appropriately selected from those conventionally used as the base component of the chemically amplified resist composition. For example, a base for a chemically amplified resist composition used to form a positive resist pattern in an alkali development process or a chemically amplified resist composition used to form a negative resist pattern in a solvent development process. The material component may be arbitrarily selected from many conventionally known base resins (for example, base resins for ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser)).
As the component (C), a resin may be used, a low molecular compound may be used, or these may be used in combination. As the component (C), one type may be used alone, or two or more types may be used in combination.

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

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

  If desired, the resist composition of the present invention may further contain miscible additives such as an additional resin for improving the performance of the resist film, a surfactant for improving coatability, a dissolution inhibitor, a plasticizer. An agent, a stabilizer, a colorant, an antihalation agent, a dye, and the like can be appropriately added and contained.

The resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone;
Ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone;
Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol;
Compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl ether, monopropyl of the polyhydric alcohols or the compound having an ester bond Derivatives of polyhydric alcohols such as ethers, monoalkyl ethers such as monobutyl ether or compounds having an ether bond such as monophenyl ether [in these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) Is preferred];
Cyclic ethers such as dioxane and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate;
Aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. be able to.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range. For example, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3. Further, when PGME and cyclohexanone are blended as polar solvents, the mass ratio of PGMEA: (PGME + cyclohexanone) is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, and even more preferably 3. : 7 to 7: 3.
In addition, as the component (S), PGMEA, EL or a mixed solvent of PGMEA and a polar solvent and a mixed solvent of γ-butyrolactone are also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
The amount of component (S) used is not particularly limited, but is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 1 -20% by mass, preferably 2-15% by mass.

The resist composition of the present invention and the component (A1) blended in the resist composition are novel ones not conventionally known.
When the component (A1) is exposed, an acid is generated from the structural unit (a0). Therefore, the component (A1) can be used as an acid generator for a chemically amplified resist composition. In addition, the component (A1) is a resin component that can form a film (resist film) alone, and its solubility in a developing solution is changed by the action of an acid, so that it also functions as a base component of a resist composition. To do. Therefore, the component (A1) alone can constitute a chemically amplified resist composition. That is, when exposure is performed on the component (A1), the acid generated from the structural unit (a0) increases the polarity of the entire component (A1). Therefore, even a film composed only of the component (A) can be formed with a resist pattern by selective exposure and development.
In addition, the resist composition of the present invention has good lithography properties such as sensitivity and resolution, and the resist pattern to be formed also has a high cross-sectional rectangularity (highly vertical pattern sidewalls). Is. The reason why these effects are obtained is not clear, but is presumed as follows. In the present invention, the acid generator site _{^{(-R f -SO 3 - Q +}} ) group containing (I) is the uniform distribution of the acid-generating sites in a resist film by being introduced into the resin. Among the above, the improvement in sensitivity is considered to be mainly due to a certain distance between the main chain and the acid generation site due to —NH—CO—O—R ¹ —. Further, the improvement of the shape is mainly due to the presence of a highly polar structure (—NH—CO—O—) containing a nitrogen atom in the vicinity of the acid generation site, thereby suppressing the diffusion of the generated acid. This is probably because of this.

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

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

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

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

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

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

≪Polymer compound≫
The polymer compound of the present invention has a structural unit (a0) containing a group represented by the following general formula (I).
The description of the polymer compound of the present invention is the same as the description of the component (A1) of the resist composition of the present invention.

［式中、Ｒ^１は直鎖状または分岐鎖状のアルキレン基であり、Ｒ^ｆは炭素数１〜４のフッ素化アルキレン基であり、Ｑ^＋は有機カチオンである。］

[Wherein, R ¹ represents a linear or branched alkylene group, R ^f represents a fluorinated alkylene group having 1 to 4 carbon atoms, and Q ⁺ represents an organic cation. ]

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
In this example, the compound represented by (m0-1) in the chemical formula is referred to as “compound (m0-1)”, and the same applies to compounds represented by other formulas.
In the analysis by NMR, the internal standard of ¹ H-NMR and the internal standard of ¹³ C-NMR is tetramethylsilane (TMS). The internal standard of ¹⁹ F-NMR is hexafluorobenzene (however, the peak of hexafluorobenzene was set to −160 ppm).
The compounds used as monomers in the polymer synthesis examples described below are shown below. Among these compounds, compound (m0-1) was synthesized according to the method disclosed in paragraphs [0115] to [0118] of International Publication No. 2009/057769. Compound (m2-1) was synthesized based on the description in International Publication No. 2010/001913.

[Polymer Synthesis Example 1: Synthesis of Polymer Compound 1]
In a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, 11.25 g (42.89 mmol) of the compound (m1-1) was dissolved in 7.74 g of methyl ethyl ketone (MEK) and 7.74 g of cyclohexanone. And heated to 80 ° C. To this solution, 7.00 g (22.13 mmol) of the compound (m2-1), 3.96 g (6.83 mmol) of the compound (m0-1), and dimethyl azobisisobutyrate (V-601) as a polymerization initiator were added. A solution prepared by dissolving 0.03 mmol in 13.99 g of MEK and 13.99 g of cyclohexanone was added dropwise over 4 hours under a nitrogen atmosphere. After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization solution was dropped into a large amount of n-heptane to precipitate a polymer, and the precipitated white powder was filtered off, washed with a mixed solvent of methanol and MEK, dried, and dried. 12.68 g of the polymer compound 1 as a product was obtained.
About this high molecular compound, the mass mean molecular weight (Mw) of standard polystyrene conversion calculated | required by GPC measurement was 12,200, and molecular weight dispersion degree (Mw / Mn) was 1.77. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n = 45.9 / It was 41.4 / 12.7.

[Polymer synthesis examples 2 to 7: Synthesis of polymer compounds 2 to 7]
Polymer compounds 2 to 7 were obtained in the same procedure as in Polymer Synthesis Example 1 except that the type and amount of monomers used were changed. Among these, polymer compounds 4 to 7 are for comparison. The high molecular compounds 4-6 respectively change the compound (m0-1) used for the synthesis | combination of the high molecular compounds 1-3 to the compound (m0'-1).
For each polymer compound, the copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR), standard polystyrene determined by GPC measurement The converted mass average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) are also shown below.

［ｌ／ｍ／ｎ／ｏ／ｐ／ｑ＝３０．７／１８．３／１５．５／１２．５／１１．１／１１．９、Ｍｗ＝１１，８００、Ｍｗ／Ｍｎ＝１．７０］

[1 / m / n / o / p / q = 30.7 / 18.3 / 15.5 / 12.5 / 11.1 / 11.9, Mw = 11,800, Mw / Mn = 1.70 ]

［ｌ／ｍ／ｎ／ｏ＝３５．８／３２．２／１９．５／１２．５、Ｍｗ＝１２，９００、Ｍｗ／Ｍｎ＝１．７８］

[1 / m / n / o = 35.8 / 32.2 / 19.5 / 12.5, Mw = 12,900, Mw / Mn = 1.78]

［ｌ／ｍ／ｎ＝４４．８／４１．０／１４．２、Ｍｗ＝１１，３００、Ｍｗ／Ｍｎ＝１．７０］

[1 / m / n = 44.8 / 41.0 / 14.2, Mw = 11,300, Mw / Mn = 1.70]

［ｌ／ｍ／ｎ／ｏ／ｐ／ｑ＝３０．４／１８．１／１５．７／１２．２／１１．４／１２．２、Ｍｗ＝１２，１００、Ｍｗ／Ｍｎ＝１．６５］

[L / m / n / o / p / q = 30.4 / 18.1 / 15.7 / 12.2 / 11.4 / 12.2, Mw = 12,100, Mw / Mn = 1.65 ]

［ｌ／ｍ／ｐ／ｑ＝３５．２／３２．６／１９．４／１２．８、Ｍｗ＝１１，５００、Ｍｗ／Ｍｎ＝１．６９］

[1 / m / p / q = 35.2 / 32.6 / 19.4 / 12.8, Mw = 11,500, Mw / Mn = 1.69]

［ｌ／ｍ＝５２．０／４８．０、Ｍｗ＝６，２００、Ｍｗ／Ｍｎ＝１．９７］

[1 / m = 52.0 / 48.0, Mw = 6,200, Mw / Mn = 1.97]

[Example 1, Comparative Example 1]
Each component shown in Table 1 was mixed and dissolved to prepare a resist composition.

In Table 1, each abbreviation has the following meaning. The numerical value in [] is a compounding amount (part by mass).
(A) -1: The polymer compound 1.
(A) -4: The polymer compound 4.
(D) -1: tri-n-octylamine.
(E) -1: salicylic acid.
(S) -3: PGMEA / PGME / CH = 30/20/50 (mass ratio) mixed solvent.

The following evaluation was performed using the obtained resist composition.
[Sensitivity evaluation (E ₀ measurement)]
The resist composition of each example was applied using a spinner on an 8-inch silicon substrate that had been subjected to hexamethyldisilazane (HMDS) treatment at 90 ° C. for 36 seconds, and baked at 100 ° C. for 60 seconds. (PAB) was performed to form a resist film having a thickness of 60 nm. Next, drawing (exposure) was performed on the resist film at an acceleration voltage of 70 keV using an electron beam drawing machine HL-800D (VSB) (manufactured by Hitachi). Then, baking treatment (PEB) was performed at 90 ° C. for 60 seconds, and development was further performed at 23 ° C. using a 2.38 mass% TMAH aqueous solution for 60 seconds. Then, water rinsing was performed for 30 seconds using pure water, followed by shake-off drying.
The above operation was performed by changing the exposure amount, and the initial exposure amount at which the resist film in the exposed portion disappeared was measured as E ₀ sensitivity. The results are shown in Table 1.

[Evaluation of resist pattern formation and shape]
The resist composition of each example was uniformly applied using a spinner on an 8-inch silicon substrate that had been subjected to HMDS treatment at 90 ° C. for 36 seconds, and baked at PAB temperature shown below for 60 seconds ( PAB) was performed to form a resist film (film thickness 60 nm). The resist film is drawn (exposed) at an acceleration voltage of 70 keV using an electron beam lithography machine HL800D (VSB) (manufactured by Hitachi), and subjected to a baking process (PEB) for 60 seconds at the PEB temperature shown below. Then, development was further performed at 23 ° C. for 60 seconds using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Then, it rinsed for 15 second using the pure water, and performed shake-off drying.
Example 1: PAB temperature / PEB temperature = 120 ° C./100° C.
Comparative Example 1: PAB temperature / PEB temperature = 130 ° C./110° C.
As a result, in each example, a line-and-space resist pattern (hereinafter referred to as “LS pattern”) having a line width of 100 nm and a pitch of 100 nm was formed.
The optimum exposure dose Eop of the LS patterns is formed (μC / cm ^2), the first embodiment is 55.4μC / cm ^2, Comparative Example 1 was 53.8μC / cm ^2. In this evaluation, in order to make Eop of Example 1 and Comparative Example 1 equivalent, the PAB temperature and the PEB temperature were set as described above.
The cross-sectional shape of the LS pattern having a line width of 100 nm and a pitch of 100 nm formed by Eop was observed with a scanning electron microscope (trade name: SU8000, manufactured by Hitachi High-Technologies Corporation).
As a result, the resist pattern formed using the resist composition of Example 1 had a good shape with high verticality of the line side wall and high rectangularity as compared with Comparative Example 1.

Claims (7)

A resist composition containing a resin component (A) that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid,
The resin component (A) is a structural unit (a0) containing a group represented by the following general formula (I), and an acrylic acid in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent A structural unit derived from an ester and containing a structural unit (a11) containing an acid-decomposable group whose polarity is increased by the action of an acid, and a hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent A resist composition comprising a polymer compound (A1) having a structural unit (a2 ^S ) which is a structural unit derived from a good acrylate ester and includes a —SO ₂ -containing cyclic group .

[Wherein, R ¹ represents a linear or branched alkylene group, R ^f represents a fluorinated alkylene group having 1 to 4 carbon atoms, and Q ⁺ represents an organic cation. ] The resist composition according to claim 1, wherein the structural unit (a0) is a structural unit represented by the following general formula (a0-1).

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, X is a divalent linking group, and R ¹ is linear or branched. An alkylene group, R ^f is a fluorinated alkylene group having 1 to 4 carbon atoms, and Q ⁺ is an organic cation. ] The polymer compound (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 includes a lactone-containing cyclic group. having a free configuration unit (a2 ^L), the resist composition according to claim 1 or 2. A step of forming a resist film on the support using the resist composition according to any one of claims 1 to 3 , a step of exposing the resist film, and developing the resist film to form a resist pattern A resist pattern forming method including a forming step. A structural unit derived from a structural unit (a0) containing a group represented by the following general formula (I) and an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent; The structural unit (a11) containing an acid-decomposable group whose polarity is increased by the action of an acid, and an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. A high molecular compound having a structural unit (a2 ^S ) including a structural unit and a —SO ₂ -containing cyclic group .

[Wherein, R ¹ represents a linear or branched alkylene group, R ^f represents a fluorinated alkylene group having 1 to 4 carbon atoms, and Q ⁺ represents an organic cation. ] The polymer compound according to claim 5 , wherein the structural unit (a0) is a structural unit represented by the following general formula (a0-1).

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, X is a divalent linking group, and R ¹ is linear or branched. An alkylene group, R ^f is a fluorinated alkylene group having 1 to 4 carbon atoms, and Q ⁺ is an organic cation. ] Furthermore, a structural unit in which the hydrogen atom bonded to the α-position carbon atom is derived from an acrylate ester which may have substituted with a substituent lactone-containing cyclic group of including configuration units (a2 ^L) The polymer compound according to claim 6 .