JP5376813B2 - Resist composition, resist pattern forming method, novel compound, and acid generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel compound useful as an acid generator for a resist composition, an acid generator, a resist composition, and a method of forming a resist pattern. <P>SOLUTION: The compound is represented by general formula (B1-1). The acid generator is composed of the compound. The resist composition contains an acid generator composed of the compound. In the formula, R<SP>x</SP>represents a hydrocarbon group which may contain a substituent group; Q<SP>1</SP>represents a 1-12C alkylene group which may contain a substituent group, or a single bond; n represents 0 or 1; Y<SP>1</SP>represents a 1-4C alkylene group or a 1-4C fluorinated alkylene group; and A<SP>+</SP>represents an organic cation which contains a nitrogen atom. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a resist composition, a method for forming a resist pattern using the resist composition, a novel compound useful as an acid generator for the resist composition, and the acid generator.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film. A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. 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 F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths 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. As a resist material that satisfies such requirements, a chemically amplified resist containing a base resin whose solubility in an alkaline developer is changed by the action of an acid and an acid generator that generates an acid upon exposure is used. For example, a positive chemically amplified resist contains, as a base resin, a resin that increases solubility in an alkaline developer by the action of an acid and an acid generator. When the acid is generated, the exposed portion becomes soluble in the alkaline developer.

Up to now, as a base resin for chemically amplified resist, polyhydroxystyrene (PHS) having high transparency with respect to KrF excimer laser (248 nm) and a resin whose hydroxyl group is protected with an acid dissociable, dissolution inhibiting group (PHS resin) Has been used. However, since the PHS resin has an aromatic ring such as a benzene ring, the transparency to light having a wavelength shorter than 248 nm, for example, 193 nm, is not sufficient. For this reason, a chemically amplified resist having a PHS resin as a base resin component has drawbacks such as low resolution in a process using 193 nm light, for example. Therefore, as a resist base resin currently used in ArF excimer laser lithography and the like, it has a structural unit generally derived from a (meth) acrylic acid ester in the main chain because it is excellent in transparency near 193 nm. Resin (acrylic resin) is used. In the case of the positive type, such a resin includes a structural unit derived from a (meth) acrylic acid ester containing a tertiary alkyl ester type acid dissociable, dissolution inhibiting group containing an aliphatic polycyclic group, for example, 2-alkyl. A resin having a structural unit derived from 2-adamantyl (meth) acrylate or the like is mainly used (for example, see Patent Document 1).
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. “(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 types of acid generators used in chemically amplified resists have been proposed so far, and for example, onium salt-based acid generators such as iodonium salts and sulfonium salts are known.
JP 2003-241385 A

Currently, perfluoroalkylsulfonic acid ions are generally used as the anion portion of the onium salt acid generator as described above. It is considered that a longer perfluoroalkyl chain of such an anion is preferable in order to suppress acid diffusion after exposure. However, perfluoroalkyl chains having 6 to 10 carbon atoms are hardly decomposable, and nonafluorobutanesulfonic acid ions or the like are used for safety in consideration of bioaccumulation. Therefore, there is a demand for a novel compound that is more suitable as an acid generator for resist compositions.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a novel compound useful as an acid generator for a resist composition, an acid generator, a resist composition, and a method for forming a resist pattern. To do.

In order to achieve the above object, the present invention employs the following configuration.
That is, the first aspect of the present invention is a resist composition comprising a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component (B) that generates an acid upon exposure. A thing,
The acid generator component (B) includes an acid generator (B1) composed of a compound represented by the following general formula (B1-1).

［式中、Ｒ^ｘは、置換基を有していてもよい芳香族炭化水素基であり；Ｑ^１は置換基を有していてもよい炭素数１〜１２のアルキレン基または単結合であり；ｎは０または１であり；Ｙ^１は炭素数１〜４のアルキレン基またはフッ素化アルキレン基であり；Ａ^＋は窒素原子を含有する有機カチオンである。］

[Wherein, R ^x is an optionally substituted aromatic hydrocarbon group ; Q ¹ is an optionally substituted alkylene group having 1 to 12 carbon atoms or a single bond. N is 0 or 1; Y ¹ is an alkylene group having 1 to 4 carbon atoms or a fluorinated alkylene group; A ⁺ is an organic cation containing a nitrogen atom; ]

  According to a second aspect of the present invention, there is provided a step of forming a resist film on a support using the resist composition of the first aspect, a step of exposing the resist film, and an alkali developing of the resist film to form a resist It is a resist pattern formation method including the process of forming a pattern.

  A third aspect of the present invention is a compound represented by the following general formula (B1-1) (hereinafter referred to as compound (B1)).

［式中、Ｒ^ｘは、置換基を有していてもよい芳香族炭化水素基であり；Ｑ^１は置換基を有していてもよい炭素数１〜１２のアルキレン基または単結合であり；ｎは０または１であり；Ｙ^１は炭素数１〜４のアルキレン基またはフッ素化アルキレン基であり；Ａ^＋は窒素原子を含有する有機カチオンである。］

[Wherein, R ^x is an optionally substituted aromatic hydrocarbon group ; Q ¹ is an optionally substituted alkylene group having 1 to 12 carbon atoms or a single bond. N is 0 or 1; Y ¹ is an alkylene group having 1 to 4 carbon atoms or a fluorinated alkylene group; A ⁺ is an organic cation containing a nitrogen atom; ]

  The fourth aspect of the present invention is an acid generator comprising the compound (B1) of the third aspect.

In the present specification and claims, unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.
Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups.
“Exposure” is a concept that includes general irradiation of radiation.

  ADVANTAGE OF THE INVENTION According to this invention, the novel compound useful as an acid generator for resist compositions, an acid generator, a resist composition, and a resist pattern formation method can be provided.

<< Compound (B1) >>
Initially, the compound (B1) which is the 3rd aspect of this invention is demonstrated. The compound (B1) is represented by the general formula (B1-1).
In formula (B1-1), R ^x represents a hydrocarbon group which may have a substituent.
Here, the hydrocarbon group of R ^x is “may have a substituent” means that part or all of the hydrogen atoms or part of the carbon atoms in the hydrocarbon group is a substituent (the hydrogen atom Or an atom or group other than a carbon atom). The number of substituents in R ^x may be one, or two or more.

The hydrocarbon group for R ^x may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
Here, in the present specification, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, and the like that do not have aromaticity.
The aromatic hydrocarbon group in R ^x may have an aromatic hydrocarbon ring in which the ring skeleton of the aromatic ring is composed only of carbon atoms, and heteroatoms other than carbon atoms may be added to the ring skeleton of the aromatic ring. It may have an aromatic heterocycle. Specifically, an aryl group in which 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, a phenanthryl group, Examples thereof include arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group and 2-naphthylethyl group. 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 a heteroaryl group in which a part of carbon atoms constituting the ring of the aryl group is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, or a carbon constituting the ring of the arylalkyl group. Examples include heteroarylalkyl groups in which a part of the atoms is substituted with the heteroatom.
Examples of the substituent of the aromatic 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 for the aromatic 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.
As the alkoxy group as the substituent of the aromatic group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group. Are preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic 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 group include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The aliphatic group for R ^x may be a saturated aliphatic group or an unsaturated aliphatic group.
The saturated aliphatic group for R ^x is preferably a linear or branched alkyl group having 1 to 10 carbon atoms or a cyclic alkyl group.
Examples of the linear alkyl 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 decanyl group. Among these, a methyl group is preferable.
Examples of the branched alkyl group include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, Examples include 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.
The linear or branched alkyl group may have a substituent. Examples of the substituent include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O). Specific examples thereof include a substituent that the aromatic group may have. The thing similar to what was mentioned as a group is mentioned.

The cyclic alkyl group may be a monocyclic group or a polycyclic group. 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.
The cyclic alkyl 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—). Examples of the substituent in the latter example are the same as those exemplified as the substituent that the aromatic group in R ^x may have.

The unsaturated aliphatic group for R ^x is preferably a linear or branched alkenyl group having 2 to 10 carbon atoms. The alkenyl group preferably has 2 to 5 carbon atoms, more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Specific examples include a vinyl group, a propenyl group (allyl group), a butynyl group, a 1-methylpropenyl group, a 2-methylpropenyl group, and the like, and a propenyl group is particularly preferable.
The alkenyl 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.

The alkylene group for Q ¹ may be linear or branched. 1-5 are preferable and, as for carbon number of this alkylene group, 1-3 are more 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 —, Alkylethylene groups such as —CH (CH ₂ CH ₃ ) CH ₂ —; trimethylene group (n-propylene group) [—CH ₂ CH ₂ CH ₂ —]; —CH (CH ₃ ) CH ₂ CH ₂ —, —CH _{2 CH (CH 3) CH 2} - alkyl trimethylene group and the like; Toramechiren group _{[-CH 2 CH 2 CH 2 CH} 2 -]; - CH (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; penta And methylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —] and the like.
Q ¹ is preferably a methylene group, an ethylene group, an n-propylene group or a single bond, and particularly preferably a single bond.

  n is 0 or 1, preferably 0.

Y ¹ is an alkylene group having 1 to 4 carbon atoms or a fluorinated alkylene group.
The _{^{Y 1, -CF 2 -, -}} CF 2 CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, - C (CF _{3) 2 -, - CF 2} CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3 _{) -, - C (CF 3} ) 2 CF 2 -, - CF (CF 2 CF 3) CF 2 -, - CF (CF 2 CF 2 CF 3) -, - C (CF 3) (CF 2 CF 3) _{-; - CHF -, - CH} 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 CF 3) - _{, -C (CH 3) (CF} 3) -, - CH 2 CH 2 CH 2 CF 2 -, - CH 2 CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C (CF ₃ ) ₂ CH ₂ —; —CH ₂ —, —CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ —, —CH (CH ₃ ) CH ₂ —, —CH (CH ₂ CH ₃ ) —, —C (CH _{3) 2 -, - CH 2} CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH (CH 3 _{) -, - C (CH 3} ) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH 3) -Etc. are mentioned.

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 -, - CF 2} CF 2 - is particularly preferred.

The organic cation of A ⁺ is not particularly limited as long as it has a nitrogen atom, and any one having a nitrogen atom may be appropriately selected from those conventionally proposed as the cation part of an onium salt acid generator. .
As A ⁺ , specifically, a substituent containing a nitrogen atom is introduced into the aryl group and / or alkyl group of an onium ion (sulfonium ion, iodonium ion, etc.) having an aryl group and / or alkyl group. Is mentioned.
Examples of the substituent containing a nitrogen atom (hereinafter referred to as N-containing substituent) include an amino group (—NH ₂ ), a substituted amino group in which part or all of the hydrogen atoms of the amino group are substituted with a substituent, and A group having at least one group selected from the group consisting of a cyclic group containing a nitrogen atom at the terminal is preferable.

Examples of the substituent in the substituted amino group include an alkyl group, an aliphatic cyclic group, and an aromatic cyclic group.
The alkyl group is preferably a linear or branched alkyl group, and the alkyl group preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms.
The alkyl group may have a substituent. Examples of the substituent of the alkyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O). Specific examples thereof include an aromatic group in R ^x . The thing similar to the thing quoted as the substituent which may be mentioned is mentioned.
Examples of the aliphatic cyclic group include those similar to those exemplified as the cyclic alkyl group in R ^x .
The aliphatic cyclic group may have a substituent. Examples of the substituent of the aliphatic cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O). Specific examples thereof include the above R ^x The thing similar to what was mentioned as a substituent which an aromatic group may have is mentioned.
Examples of the aromatic cyclic group include those similar to those exemplified as the aromatic hydrocarbon group in R ^x .
The aromatic cyclic group may have a substituent. Examples of the substituent of the aromatic cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O) and the like. Specific examples thereof include the above R ^x . The thing similar to what was mentioned as a substituent which an aromatic group may have is mentioned.

A ⁺ preferably has a group represented by the following general formula (I) as an N-containing substituent.

［式中、Ｗ^１は酸素原子または硫黄原子であり；Ｑ^２はアルキレン基または単結合であり；Ｒ^７、Ｒ^８はそれぞれ独立に、水素原子、置換基を有していてもよいアルキル基、置換基を有していてもよい脂肪族環式基、または置換基を有していてもよい芳香族環式基であり、Ｒ^７およびＲ^８が相互に結合して環を形成してもよい。］

[Wherein, W ¹ is an oxygen atom or a sulfur atom; Q ² is an alkylene group or a single bond; R ⁷ and R ⁸ are each independently a hydrogen atom or an alkyl group optionally having a substituent. , An aliphatic cyclic group that may have a substituent, or an aromatic cyclic group that may have a substituent, and R ⁷ and R ⁸ are bonded to each other to form a ring Also good. ]

In the formula, the alkylene group for Q ² is preferably a linear or branched alkylene group, preferably having 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms.
As the alkyl group, aliphatic cyclic group, and aromatic cyclic group of R ⁷ and R ⁸ , respectively, the alkyl group, aliphatic cyclic group, and aromatic cyclic group mentioned as the substituent in the substituted amino group The same thing is mentioned.
When R ⁷ and R ⁸ are bonded to each other to form a ring, the ring is preferably a 3- to 8-membered ring, and more preferably a 5- to 7-membered ring.
The ring may have a substituent. Examples of the substituent that the ring may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O). Specific examples thereof include the R ^The thing similar to what was mentioned as a substituent which the aromatic group may have in ^x is mentioned.

In A ⁺ , the group represented by the general formula (I) is preferably bonded to an oxygen atom or a sulfur atom in view of ease of production.

Preferable specific examples of A ⁺ include, for example, a cation moiety represented by the following general formula (b-1), (b-2), (b-5) or (b-6).

［式中、Ｒ^ｘ、Ｑ^１、ｎ、Ｙ^１は前記と同じであり；Ｒ^１〜Ｒ^３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、または置換基を有していてもよいアルキル基であって、Ｒ^１〜Ｒ^３のうち少なくとも１つはアリール基であり、Ｒ^１〜Ｒ^３のうち少なくとも１つは下記一般式（Ｉ−１）で表される置換基を有する。または、Ｒ^１およびＲ^２が相互に結合して式中のイオウ原子と共に環を形成し、Ｒ^３は、置換基を有していてもよいアリール基、置換基を有していてもよいアルキル基、または−Ｒ^４−Ｃ（＝Ｏ）−Ｒ^５（式中、Ｒ^４は炭素数１〜５のアルキレン基であり、Ｒ^５は置換基を有していてもよいアリール基である。）であり、前記環およびＲ^３の一方または両方が、下記一般式（Ｉ−１）で表される置換基を有する。］

[Wherein, R ^x , Q ¹ , n, and Y ¹ are the same as described above; R ^{1 to} R ³ each independently have an aryl group that may have a substituent, or a substituent. And at least one of R ^{1 to} R ³ is an aryl group, and at least one of R ^{1 to} R ³ is a substituent represented by the following general formula (I-1) Has a group. Alternatively, R ¹ and R ² are bonded to each other to form a ring together with the sulfur atom in the formula, and R ³ is an aryl group which may have a substituent, or an alkyl which may have a substituent. Group, or —R ⁴ —C (═O) —R ⁵ (wherein R ⁴ is an alkylene group having 1 to 5 carbon atoms, and R ⁵ is an aryl group which may have a substituent). And one or both of the ring and R ³ have a substituent represented by the following general formula (I-1). ]

［式中、Ｗ^１、Ｑ^２、Ｒ^７、Ｒ^８はそれぞれ前記と同じであり、Ｗ^２は二価の連結基であり、ｄは０または１である。］

[Wherein, W ¹ , Q ² , R ⁷ and R ⁸ are the same as defined above, W ² is a divalent linking group, and d is 0 or 1. ]

［式中、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、または置換基を有していてもよいアルキル基であり、Ｒ^５〜Ｒ^６のうち少なくとも１つは前記一般式（Ｉ−１）で表される置換基を有する。］

[Wherein, R ^{5 to} R ⁶ are each independently an aryl group which may have a substituent, or an alkyl group which may have a substituent, and at least of R ^{5 to} R ⁶ . One has a substituent represented by the general formula (I-1). ]

［式中、Ｒ^４１〜Ｒ^４３はそれぞれ独立して、前記一般式（Ｉ−１）で表される置換基、アルキル基、アセチル基、アルコキシ基、カルボキシ基、またはヒドロキシアルキル基であり、Ｒ^４１〜Ｒ^４３のうち少なくとも１つは前記一般式（Ｉ−１）で表される置換基であり；ｎ_１は０〜５の整数であり、ｎ_２〜ｎ_３はそれぞれ独立して０〜３の整数であり、ｎ_１＋ｎ_２＋ｎ_３は１以上の整数である。］

[Wherein, R ^{41 to} R ⁴³ each independently represent a substituent represented by the general formula (I-1), an alkyl group, an acetyl group, an alkoxy group, a carboxy group, or a hydroxyalkyl group; ^At least one of ^{41 to} R ⁴³ is a substituent represented by the general formula (I-1); n ₁ is an integer of 0 to 5, and n _{2 to} n ₃ are each independently 0 to 3 is an integer, and n ₁ + n ₂ + n ₃ is an integer of 1 or more. ]

［式中、Ｒ^４４〜Ｒ^４６はそれぞれ独立して、前記一般式（Ｉ−１）で表される置換基、アルキル基、アセチル基、アルコキシ基、カルボキシ基、またはヒドロキシアルキル基であり、Ｒ^４４〜Ｒ^４６のうち少なくとも１つは前記一般式（Ｉ−１）で表される置換基であり；ｎ_４は０〜５の整数であり、ｎ_５は０〜３の整数であり、ｎ_６は０〜２の整数であり、ｎ_４＋ｎ_５＋ｎ_６は１以上の整数である。］

[Wherein, R ^{44 to} R ⁴⁶ are each independently a substituent represented by the general formula (I-1), an alkyl group, an acetyl group, an alkoxy group, a carboxy group, or a hydroxyalkyl group; ^At least one of ^{44 to} R ⁴⁶ is a substituent represented by the general formula (I-1); n ₄ is an integer of 0 to ₅ , n ₅ is an integer of 0 to 3, and n ₆ is an integer of 0 to 2, and n ₄ + n ₅ + n ₆ is an integer of 1 or more. ]

Any of the cation moieties represented by the general formula (b-1), (b-2), (b-5) or (b-6) is a substitution represented by the general formula (I-1). It has at least one group (hereinafter referred to as substituent (I-1)).
In formula (I-1), examples of the divalent linking group for W ² include an alkylene group and a group containing a hetero atom (hereinafter referred to as a hetero atom-containing linking group).
The alkylene group is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and most preferably an ethylene group.
The “hetero atom” in the hetero atom-containing linking group is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a sulfur atom, and a nitrogen atom.
Examples of the hetero atom-containing linking group include an oxygen atom (ether bond; —O—), a sulfur atom (thioether bond; —S—), a —NH— bond (H is a substituent such as an alkyl group or an acyl group). Non-hydrocarbon hetero atom-containing linkages such as ester bonds (—COO—), amide bonds (—CONH—), carbonyl groups (—CO—), carbonate bonds (—OCOO—), etc. Group; a combination of the non-hydrocarbon hetero atom-containing linking group and the alkylene group. Examples of the combination include -R ⁹¹ -O- (wherein R ⁹¹ is an alkylene group). In the above formula, examples of the alkylene group for R ⁹¹ include the same alkylene groups as those described above for the divalent linking group for W ² .
In the present invention, the divalent linking group for W ² is preferably an oxygen atom, a sulfur atom or the aforementioned —R ⁹¹ —O—, particularly preferably an oxygen atom or the aforementioned —R ⁹¹ —O—.

In formula (b-1), the aryl group of R ^{1 to} R ³ is not particularly limited, and examples thereof include an unsubstituted aryl group having 6 to 20 carbon atoms and a part of hydrogen atoms of the unsubstituted aryl group. Alternatively, a substituted aryl group in which all of them are substituted with a substituent (I-1), an alkyl group, an alkoxy group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, a halogen atom, a hydroxyl group and the like can be mentioned.
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 in the substituted aryl 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.
The alkoxy group in the substituted aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, and most preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group. preferable.
The halogen atom in the substituted aryl group is preferably a fluorine atom.
Examples of the alkoxyalkyloxy group in the substituted aryl group include, for example, a general formula: —O—C (R ⁴⁷ ) (R ⁴⁸ ) —O—R ⁴⁹ [wherein R ⁴⁷ and R ⁴⁸ are each independently a hydrogen atom or It is a linear or branched alkyl group, and R ⁴⁹ is an alkyl group. ] Is represented.
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.

Examples of the alkoxycarbonylalkyloxy group in the substituted aryl group include, for example, a general formula: —O—R ⁵⁰ —C (═O) —O—R ⁵¹ [wherein R ⁵⁰ is a linear or branched alkylene group. And R ⁵¹ is a tertiary alkyl group. ] Is represented.
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 ⁵¹ , 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.

The alkyl group of R ¹ to R ^3, is not particularly limited, for example, linear C1-10, branched or cyclic alkyl group, and the like. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
The alkyl group of R ^{1 to} R ³ may have a substituent. Examples of the substituent include a substituent (I-1), an alkoxy group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, a halogen atom, a hydroxyl group, and the like. Specific examples of these include the substituted aryl group. The thing similar to a thing is mentioned.

Of R ^{1 to} R ³ , at least one is an aryl group, preferably 2 or more are aryl groups, and most preferably all of R ^{1 to} R ³ are aryl groups. The aryl group is preferably a phenyl group or a naphthyl group.
In addition, at least one, preferably 1 or 2, and particularly preferably one of R ^{1 to} R ³ preferably has the substituent (I-1) as a substituent. Moreover, it is preferable that this substituent (I-1) has couple | bonded with the aryl group. That is, at least one of R ^{1 to} R ³ is preferably an aryl group having a substituent (I-1).
R ^{1 to} R ³ may each have a substituent other than the substituent (I-1) as described above.

In the formula (b-1), R ¹ and R ² may be bonded to each other to form a ring together with the sulfur atom in the formula. In this case, the ring is preferably a 3- to 10-membered ring including a sulfur atom, and particularly preferably a 5- to 7-membered ring.
When R ¹ and R ² are bonded to each other to form a ring together with the sulfur atom in the formula, R ³ is an aryl group which may have a substituent, or an alkyl group which may have a substituent. Or —R ⁴ —C (═O) —R ⁵ (wherein R ⁴ is an alkylene group having 1 to 5 carbon atoms, and R ⁵ is an aryl group which may have a substituent). It is.
Examples of the aryl group and alkyl group for R ³ include the same aryl groups and alkyl groups as those described above for R ^{1 to} R ³ .
The alkylene group for R ⁴ is preferably a linear or branched alkyl group, and preferably has 1 to 5 carbon atoms.
Examples of the aryl group for R ⁵ include the same aryl groups as those described above for R ^{1 to} R ³ .
When R ¹ and R ² are bonded to each other to form a ring together with the sulfur atom in the formula, one or both of the ring and R ³ have the substituent (I-1).
The substituent (I-1) is preferably bonded to an aryl group. That is, R ³ is an aryl group having a substituent (I-1), or — (R ⁴ ) —C (═O) —R ⁵ , and the R ⁵ aryl group has a substituent (I -1) is preferably a bonded group.

  The cation moiety represented by the formula (b-1) is preferably a cation moiety represented by the following formula (b-1-1) or (b-1-2). The cation moiety represented is particularly preferred.

In formula (b-1-1), W ² , Q ² , R ⁷ ′, and R ⁸ ′ are the same as W ² , R ⁷ , and R ^{8 in} formula (I-1), respectively.
The bonding position of —W ² — (C (═O)) _d —Q ² —N (R ⁷ ′) (R ⁸ ′) is not particularly limited, but the 3- or 4-position of the phenyl group is preferable, and the 4-position is preferred. Is most preferred.
R ¹ ′ is an alkyl group or an alkoxy group. Examples of the alkyl group and alkoxy group are the same as those exemplified as the alkyl group and alkoxy group in the substituted aryl group in the description of R ^{1 to} R ³ .
a is an integer of 0-2.
d is 0 or 1.
R ² ′ and R ³ ′ are each independently —W ² — (C (═O)) _d -Q ² —N (R ⁷ ′) (R ⁸ ′), an alkyl group or an alkoxy group. The _{^{-W 2 - (C (= O}} )) d -Q 2 -N (R 7 ') (R 8'), an alkyl group, an alkoxy group the same as defined above.
b and c are each independently an integer of 0 to 3, preferably 0 or 1.

In formula (b-1-2), W ² , R ⁷ ′, and R ⁸ ′ are the same as W ² , R ⁷ , and R ^{8 in} formula (I-1), respectively.
Ar is an aryl group. Examples of the aryl group include the same aryl groups as those described above for R ^{1 to} R ³ , and a phenyl group is most preferable.
d is 0 or 1.
e is an integer of 0 to 3, and 1 or 2 is most preferable.

In formula (b-2), examples of the aryl group and alkyl group of R ^{5 to} R ⁶ include the same aryl groups and alkyl groups as R ^{1 to} R ³ , respectively.
Among R ⁵ to R ^6, it is preferable that at least one is an aryl ^group, it is preferred that all of R 5 to R ⁶ is an aryl group. Among them, it is most preferable that all of R ^{5 to} R ⁶ are phenyl groups.
Further, at least one, preferably one of R ^{5 to} R ⁶ has the substituent (I-1). The substituent (I-1) is preferably bonded to an aryl group. That is, it is preferable that at least one of R ^{5 to} R ³ is an aryl group having a substituent (I-1).
R ^{5 to} R ⁶ may each have a substituent other than the substituent (I-1) as described above.

In formula (b-5), in R ^{41 to} R ⁴³ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group or 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.
n ₁ is preferably 1 to 3.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
When n ₁ , n ₂ or n ₃ is an integer of 2 or more, the plurality of R ⁴¹ , R ⁴² or R ⁴³ may be the same or different.
At least one, preferably one of R ^{41 to} R ⁴³ is the substituent (I-1). In particular, R ⁴¹ preferably has a substituent (I-1).
^Further, as R 41 ^{to R 43,} as described above, it may have a substituent other than a substituent (I-1).

In formula (b-6), examples of R ^{44 to} R ⁴⁶ include the same as R ^{41 to} R ⁴³ .
n ₄ is preferably 1 to 3.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1.
When n ₄ , n ₅ or n ₆ is an integer of 2 or more, the plurality of R ⁴⁴ , R ⁴⁵ or R ⁴⁶ may be the same or different.
At least one, preferably one of R ^{44 to} R ⁴⁶ is the substituent (I-1). In particular, R ⁴⁴ preferably has a substituent (I-1).
^Further, as R 44 ^{to R 46,} as described above, it may have a substituent other than a substituent (I-1).

In the present invention, A ⁺ is preferably a cation moiety represented by the formula (b-1).
That is, as the compound (B1), a compound represented by the following general formula (B1-1-1) is preferable.

［式中、Ｒ^ｘ、Ｑ^１、Ｙ^１、Ｒ^１〜Ｒ^３はそれぞれ前記と同じである。］

[Wherein, R ^x , Q ¹ , Y ¹ , R ^{1 to} R ³ are the same as defined above. ]

<Method for producing compound (B1)>
Although it does not specifically limit as a manufacturing method of a compound (B1), For example, the compound (b0-1) represented by the following general formula (b0-1), and the compound represented by the following general formula (b0-2) The manufacturing method including the process of making (b0-2) react is mentioned.

Wherein ^(b0-1), a ^{R x, Q 1, n,} Y 1 each the formula (B1-1) in the ^{R x,} Q ^{1, n,} same as ^{Y 1.}
M ⁺ is an alkali metal ion. Examples of the alkali metal ion include sodium ion, lithium ion, potassium ion and the like, and sodium ion or lithium ion is preferable.
In the formula (b0-2), A ⁺ is the same as A ⁺ in the formula (B1-1).
Z ⁻ is a halogen ion, a sulfonate ion, BF ₄ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , PF ₆ ^— or ClO ₄ ^— .
Examples of the halogen ion in Z ⁻ include bromine ion, chlorine ion and iodine ion, and bromine ion and chlorine ion are preferable.
Z ^- The sulfonic acid ion in, p- toluenesulfonate ion, methanesulfonate ion, benzenesulfonate ion, trifluoromethanesulfonate ion, and the like.

As the compound (b0-1) and the compound (b0-2), commercially available compounds may be used or synthesized.
Although the manufacturing method of compound (b0-1) is not specifically limited, For example, the compound represented by the following general formula (b0-1-11) is made into sodium hydroxide, lithium hydroxide, etc. in solvent, such as tetrahydrofuran and water. To give a compound represented by the following general formula (b0-1-12) in an aqueous solution of an alkali metal hydroxide, and then the compound is converted into an acidic catalyst in an organic solvent such as benzene or dichloroethane. In the presence, by dehydration condensation with an alcohol represented by the following general formula (b0-1-13), a compound in which n in the general formula (b0-1) is 1 (the following general formula (b0-1) −01)) is obtained.

［式中、Ｒ^２１は炭素数１〜５のアルキル基であり、Ｒ^ｘ、Ｑ^１、Ｙ^１、Ｍ^＋はそれぞれ式（ｂ０−１）中のＲ^ｘ、Ｑ^１、Ｙ^１、Ｍ^＋と同じである。］

^{Wherein, R 21} is an alkyl group of 1 to 5 carbon ^{atoms, R x, Q 1, Y} 1, M + , respectively formula (b0-1) in the ^{R x, Q 1, Y 1} , M + Is the same. ]

In addition, for example, fluorine silver, a compound represented by the following general formula (b0-1-01), and a compound represented by the following general formula (b0-1-02) in an organic solvent such as anhydrous diglyme To obtain a compound represented by the following general formula (b0-1-03), and the compound in an organic solvent such as tetrahydrofuran, acetone or methyl ethyl ketone, and an alkali such as sodium hydroxide or lithium hydroxide. By reacting with a metal hydroxide, a compound in which n in the general formula (b0-1) is 0 (a compound represented by the following general formula (b0-1-0)) is obtained.
Examples of the halogen atom for _{X h} in the formula (b0-1-02), bromine atom or a chlorine atom is preferable.

［式中、Ｒ^ｘ、Ｑ^１、Ｙ^１、Ｍ^＋はそれぞれ式（ｂ０−１）中のＲ^ｘ、Ｑ^１、Ｙ^１、Ｍ^＋と同じであり、Ｘ_ｈはハロゲン原子である。］

^{Wherein, R x, Q 1, Y} 1, M + is the same as ^R x, respectively formula (b0-1) in ^{a Q 1, Y 1, M +} , X h represents a halogen atom. ]

The method for producing compound (b0-2) is not particularly limited. For example, an onium salt generally used as a raw material for an onium salt-based acid generator usually does not contain a nitrogen atom, but an N-containing substituent as described above is added to the cation portion of the onium salt by a known method. It can be obtained by introducing.
As a specific example, for example, in the case where the A ⁺ is an onium salt having a substituent (I-1), for example, as a substituent, —W ² —H (wherein W ² is the same as described above) When an onium salt having a cation moiety having a cation moiety and a compound (I-0) represented by the following general formula (I-0) is reacted, hydrogen of —W ² —H atom ^- is substituted by ^{(C (= W 1))} d-Q 2 -N (R 7) (R 8). Thereby, the onium salt which has A ^<+> which has the said substituent (I-1) is obtained.

［式中、Ｗ^１、Ｑ^２、Ｒ^７、Ｒ^８はそれぞれ前記と同じであり、Ｘ_ｈ’ はハロゲン原子である。ｄは０または１である。］

[Wherein, W ¹ , Q ² , R ⁷ and R ⁸ are the same as defined above, and X _h ′ is a halogen atom. d is 0 or 1. ]

Examples of the halogen atom for X _h ′ include a bromine atom, a chlorine atom, and an iodine atom, and a bromine atom or a chlorine atom is preferable.
A commercially available compound can be used as the compound (I-0).
The reaction of the onium salt and the compound (I-0) can be carried out, for example, by dissolving the onium salt in a solvent such as tetrahydrofuran and adding the compound (I-0) in the presence of a base.
The amount of compound (I-0) to be used is generally 1 to 100 mol times, preferably 1.5 to 10 mol times based on the onium salt.
Examples of the base used for the reaction include triethylamine, pyridine, potassium hydroxide, sodium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate and the like.
The amount of the base to be used is generally within the range of 1.0 to 10.0 mol times, preferably 2.0 to 4.0 mol times, relative to compound (I-0).
As the solvent, aprotic organic solvents such as tetrahydrofuran, toluene, dichloromethane, pyridine, DMF, DMSO, and acetone are preferable.
The reaction temperature is usually 20 to 150 ° C, preferably 50 to 100 ° C. Moreover, reaction time is 0.1 to 72 hours normally, and it is preferable to set it as 1 to 24 hours.

The compound (b0-1) and the compound (b0-2) are reacted, for example, by dissolving these compounds in a solvent such as water, dichloromethane, acetonitrile, methanol, chloroform, methylene chloride, and the like. Can do.
The reaction temperature is preferably about 0 ° C to 150 ° C, more preferably about 0 ° C to 100 ° C. The reaction time varies depending on the reactivity of the compound (b0-1) and the compound (b0-2), the reaction temperature, and the like, but usually 0.5 to 10 hours is preferable, and 1 to 5 hours is more preferable.
The amount of compound (b0-2) used in the above reaction is usually preferably about 0.5 to 2 mol per 1 mol of compound (b0-1).

The structure of the compound obtained as described above includes ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum method, mass spectrometry (MS ) Method, elemental analysis method, X-ray crystal diffraction method, etc.

  Compound (B1) is a novel compound that can be used as an acid generator, and can be blended in a resist composition as an acid generator.

≪Acid generator≫
The acid generator of the 4th aspect of this invention consists of a compound (B1) of said 1st aspect.
The acid generator is useful as an acid generator for a chemically amplified resist composition, for example, an acid generator component (B) of a resist composition according to the first aspect of the present invention described later.

≪Resist composition≫
The resist composition of the first aspect of the present invention generates a base component (A) (hereinafter referred to as component (A)) whose solubility in an alkaline developer is changed by the action of an acid, and an acid upon exposure. An acid generator component (B) (hereinafter referred to as component (B)) is contained, and the component (B) is an acid generator (B1) composed of a compound represented by the general formula (B1-1). Including.
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 component (B), and the acid has a solubility in the alkaline developer of the component (A). Change. As a result, while the solubility of the exposed portion of the resist film in the alkaline developer changes, the unexposed portion does not change the solubility in the alkaline developer. In the case of the negative type, the unexposed part is dissolved and removed, and a resist pattern is formed.
The resist composition of the present invention may be a negative resist composition or a positive resist composition.

<(A) component>
As the component (A), organic compounds that are usually used as base material components for chemically amplified resists can be used singly or in combination of two or more.
Here, the “base material component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
The organic compound having a molecular weight of 500 or more is largely classified into a low molecular weight organic compound having a molecular weight of 500 or more and less than 2000 (hereinafter referred to as a low molecular compound) and a high molecular weight resin having a molecular weight of 2000 or more (polymer material). Separated. As the low molecular weight compound, a non-polymer is usually used. In the case of a resin (polymer, copolymer), a polystyrene-reduced mass average molecular weight by GPC (gel permeation chromatography) is used as the “molecular weight”. Hereinafter, the term “resin” refers to a resin having a molecular weight of 2000 or more.
As the component (A), a resin whose alkali solubility is changed by the action of an acid can be used, and a low molecular weight material whose alkali solubility is changed by the action of an acid can also be used.

When the resist composition of the present invention is a negative resist composition, as the component (A), a base material component that is soluble in an alkali developer is used, and a crosslinking agent is further added to the negative resist composition.
In such a negative resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause crosslinking between the base material component and the crosslinking agent, resulting in poor solubility in an alkali developer. To do. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the negative resist composition on the substrate is selectively exposed, the exposed portion turns into poorly soluble in an alkaline developer, while unexposed. Since the portion remains soluble in the alkali developer and does not change, a resist pattern can be formed by alkali development.
As the component (A) of the negative resist composition, a resin that is soluble in an alkali developer (hereinafter referred to as an alkali-soluble resin) is usually used.
As the alkali-soluble resin, a resin having a unit derived from at least one selected from α- (hydroxyalkyl) acrylic acid or a lower alkyl ester of α- (hydroxyalkyl) acrylic acid is a good resist with little swelling. A pattern can be formed, which is preferable. Α- (Hydroxyalkyl) acrylic acid includes acrylic acid in which a hydrogen atom is bonded to the α-position carbon atom to which the carboxy group is bonded, and a hydroxyalkyl group (preferably having 1 carbon atom) in the α-position carbon atom. One or both of [alpha] -hydroxyalkylacrylic acids to which (5) hydroxyalkyl groups) are attached.
As the crosslinking agent, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent 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 positive resist composition, as the component (A), a base material component whose solubility in an alkaline developer is increased by the action of an acid is used. The component (A) is hardly soluble in an alkali developer before exposure. When an acid is generated from the component (B) by exposure, the solubility in the alkali developer is increased by the action of the acid. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the positive resist composition on the substrate is selectively exposed, the exposed portion changes from poorly soluble to soluble in an alkaline developer. On the other hand, since the unexposed portion remains hardly soluble in alkali and does not change, a resist pattern can be formed by alkali development.

In the resist composition of the present invention, the component (A) is preferably a base material component whose solubility in an alkaline developer is increased by the action of an acid. That is, the resist composition of the present invention is preferably a positive resist composition.
The component (A) may be a resin component (A1) (hereinafter also referred to as component (A1)) whose solubility in an alkaline developer is increased by the action of an acid. It may be a low molecular compound (A2) (hereinafter sometimes referred to as the component (A2)) whose solubility in a liquid is increased, or a mixture thereof.

[(A1) component]
As the component (A1), resin components (base resins) that are usually used as base components for chemically amplified resists can be used alone or in combination of two or more.
In the present invention, the component (A1) preferably contains a structural unit derived from an acrylate ester.
Here, in the present specification and claims, the “structural unit” means a monomer unit (monomer unit) constituting the resin component (polymer).
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include those in which a hydrogen atom is bonded to the carbon atom at the α-position, and those in which a substituent (atom or group other than a hydrogen atom) is bonded to the carbon atom in the α-position. Include concepts. Examples of the substituent include a lower alkyl group and a halogenated lower alkyl 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.
The “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.
In the acrylate ester, as the lower alkyl group as a substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, Examples include lower linear or branched alkyl groups such as isopentyl group and neopentyl group.
Specific examples of the halogenated lower alkyl group include groups in which part or all of the hydrogen atoms in the above-mentioned “lower alkyl group as a substituent at the α-position” are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and is a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group. In view of industrial availability, a hydrogen atom or a methyl group is most preferable.

The component (A1) particularly preferably has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
In addition to the structural unit (a1), the component (A1) preferably further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.
The component (A1) is a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group in addition to the structural unit (a1) or in addition to the structural units (a1) and (a2). It is preferable to have (a3).

・ Structural unit (a1)
The acid dissociable, dissolution inhibiting group in the structural unit (a1) has an alkali dissolution inhibiting property that makes the entire component (A1) difficult to dissolve in an alkali developer before dissociation, and dissociates with an acid. This increases the solubility of the entire component in an alkaline developer, and those that have been proposed as acid dissociable, dissolution inhibiting 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, dissolution inhibiting group such as an alkoxyalkyl group is widely known. .

Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (O)). 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.
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, dissolution inhibiting group” for convenience.
Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include an aliphatic branched acid dissociable, dissolution inhibiting group and an acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group.

“Aliphatic branched” means having a branched structure having no aromaticity. The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
As the aliphatic branched acid dissociable, dissolution inhibiting group, a tertiary alkyl group having 4 to 8 carbon atoms is preferable, and specific examples include a tert-butyl group, a tert-pentyl group, and a tert-heptyl group. .

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a1) may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The “aliphatic cyclic group” is preferably a polycyclic group.
Examples of the aliphatic cyclic group include monocycloalkanes, bicycloalkanes, tricycloalkanes, tetracycloalkanes which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. And groups obtained by removing one or more hydrogen atoms from a polycycloalkane. More specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are exemplified. .

  Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group. Specifically, 2-methyl-2 -Adamantyl group, 2-ethyl-2-adamantyl group, etc. are mentioned. Alternatively, in the structural units represented by the following general formulas (a1 ″ -1) to (a1 ″ -6), an adamantyl group such as a group bonded to an oxygen atom of a carbonyloxy group (—C (O) —O—) An aliphatic cyclic group such as a cyclohexyl group, a cyclopentyl group, a norbornyl group, a tricyclodecanyl group, or a tetracyclododecanyl group, and a branched alkylene group having a tertiary carbon atom bonded thereto. Groups.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｒ^１５、Ｒ^１６はアルキル基（直鎖状、分岐鎖状のいずれでもよく、好ましくは炭素数１〜５である）を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹⁵ and R ^{16 each} represents an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms. Is). ]

  In the general formulas (a1 ″ -1) to (a1 ″ -6), the lower alkyl group or halogenated lower alkyl group of R is a lower alkyl group or halogenated lower alkyl which may be bonded to the α-position of the acrylate ester. It is the same as the alkyl group.

The “acetal acid dissociable, dissolution inhibiting group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal acid dissociable, dissolution inhibiting group is bonded.
Examples of the acetal type acid dissociable, dissolution inhibiting 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低級アルキル基を表し、ｎは０〜３の整数を表し、Ｙは低級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 a lower alkyl group, n represents an integer of 0 to 3, and Y represents a lower alkyl group or an aliphatic cyclic group. ]

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

［式中、Ｒ^１’、ｎ、Ｙは上記と同様である。］

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

Examples of the lower alkyl group for Y include the same lower alkyl groups as those described above for R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as those in the formula group.

  Examples of the acetal type acid dissociable, dissolution inhibiting 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も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、分岐鎖状または環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状または分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

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

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

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

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^１は酸解離性溶解抑制基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; and X ¹ represents an acid dissociable, dissolution inhibiting group. ]

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^２は酸解離性溶解抑制基を示し；Ｙ^２はアルキレン基または脂肪族環式基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents an alkylene group or an aliphatic cyclic group. ]

In general formula (a1-0-1), the lower alkyl group or halogenated lower alkyl group for R is the same as the lower alkyl group or halogenated lower alkyl group that may be bonded to the α-position of the acrylate ester. .
X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. And tertiary alkyl ester type acid dissociable, dissolution inhibiting groups are preferred.

In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).
Y ² is preferably an alkylene group having 1 to 10 carbon atoms or a divalent aliphatic cyclic group, and a group in which two or more hydrogen atoms are removed is used as the aliphatic cyclic group. Except for the above, the same “aliphatic cyclic group” as described above can be used.
When Y ² is an alkylene group having 1 to 10 carbon atoms, it is more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. .
When Y ² is a divalent aliphatic cyclic group, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, or tetracyclododecane is particularly preferable. .

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

［上記式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５の低級アルキル基、または脂肪族環式基を表し；ｎは０〜３の整数を表し；Ｙ^２はアルキレン基または脂肪族環式基を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５の低級アルキル基を表す。］

[In the above formula, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents a lower alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; Y ² represents an alkylene group or an aliphatic cyclic group; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms; Represents. ]

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

  Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
Among the above, the structural unit represented by the general formula (a1-1) is preferable, and specifically, (a1-1-1) to (a1-1-6) and (a1-1-35) to (a1). It is more preferable to use at least one selected from the group -1-41).
Furthermore, as the structural unit (a1), in particular, those represented by the following general formula (a1-1-01) including the structural units of the formulas (a1-1-1) to (a1-1-4) The following general formula (a1-1-02) including the structural units of formulas (a1-1-35) to (a1-1-41) is also preferable.

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１１は低級アルキル基を示す。）

(In the formula, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group.)

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１２は低級アルキル基を示す。ｈは１〜３の整数を表す。）

(In the formula, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ¹² represents a lower alkyl group, and h represents an integer of 1 to 3.)

In general formula (a1-1-01), R is the same as defined above.
The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group.
In general formula (a1-1-02), R is the same as defined above.
The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group. h is preferably 1 or 2, and most preferably 2.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, more preferably 25 to 50 mol%, based on all structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

・ Structural unit (a2)
The structural unit (a2) is a structural unit derived from an acrylate ester containing a lactone-containing cyclic group.
Here, the lactone-containing cyclic group refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure. The lactone ring is counted as the first ring, and when it is only the lactone ring, 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 of the structural unit (a2) has an affinity for a developer containing water or a high-molecular compound (A1) when the polymer film (A1) is used for forming a resist film. It is effective in improving the sex.

As the structural unit (a2), any unit can be used without any particular limitation.
Specifically, examples of the lactone-containing monocyclic group include groups in which one hydrogen atom has been removed from γ-butyrolactone. 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.

  More specifically, examples of the structural unit (a2) include structural units represented by general formulas (a2-1) to (a2-5) shown below.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基であり、Ｒ’は水素原子、低級アルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり、前記Ｒ”は水素原子、または炭素数１〜１５の直鎖状、分岐鎖状もしくは環状のアルキルキル基であり、ｍは０または１の整数であり、Ａ”は炭素数１〜５のアルキレン基または酸素原子である。］

[Wherein, R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ′ is a hydrogen atom, a lower alkyl group, an alkoxy group having 1 to 5 carbon atoms, or —COOR ″, wherein R ″ is A hydrogen atom or a linear, branched or cyclic alkylalkyl group having 1 to 15 carbon atoms, m is an integer of 0 or 1, and A ″ is an alkylene group having 1 to 5 carbon atoms or an oxygen atom. is there.]

R in the general formulas (a2-1) to (a2-5) is the same as R ¹ in the structural unit (a1 ′).
As the lower alkyl group for R ′, the same as the lower alkyl group for R ¹ in the structural unit (a1 ′) can be exemplified.
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 fluorine atom A group in which one or more hydrogen atoms are removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, etc., which may or may not be substituted with an alkyl group. Specific examples thereof include monocycloalkanes such as cyclopentane and cyclohexane, groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Can be mentioned.
Specific examples of the alkylene group having 1 to 5 carbon atoms of A ″ include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.
Below, the specific structural unit of the said general formula (a2-1)-(a2-5) is illustrated.

  As the structural unit (a2), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formulas (a2-1) to ( At least one selected from the group consisting of structural units represented by a2-3) is more preferred. Among them, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-2), (a2-3-1), (a2-3-2) ), (A2-3-9) and (a2-3-10), at least one selected from the group consisting of structural units represented by (a2-3-10) is preferred.

As the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a2) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, with respect to the total of all the 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 structural unit (a3) is a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A1) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. Contributes to improvement.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). It is done. As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

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

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

(Wherein R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, and l is an integer of 1 to 5) And s is an integer of 1 to 3.)

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and a hydroxyl group bonded to the 3rd position of the adamantyl group is particularly preferred.
In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. These preferably have a 2-norbornyl group or a 3-norbornyl group bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, and more preferably 5 to 25 mol% with respect to all the structural units constituting the component (A1). Is 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.

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

（式中、Ｒは前記と同じである。）

(In the formula, R is as defined above.)

  When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) in the component (A1) is 1 to 30 with respect to the total of all the structural units constituting the component (A1). Mol% is preferable and 10 to 20 mol% is more preferable.

  In the present invention, the component (A1) preferably contains a copolymer having the structural units (a1), (a2) and (a3). Examples of the copolymer include copolymers composed of the structural units (a1), (a2) and (a3), copolymers composed of the structural units (a1), (a2), (a3) and (a4). Can be mentioned.

The component (A1) can be obtained by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN).
Further, for the component (A1), in the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that the terminal A —C (CF ₃ ) ₂ —OH group may be introduced into the. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000, and 5000 to 20000. Most preferred. If it is smaller than the upper limit of this range, there is sufficient solubility in a resist solvent to be used as a resist, and if it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. In addition, Mn shows a number average molecular weight.

[(A2) component]
As the component (A2), a low molecular compound having a molecular weight of 500 or more and less than 2000 and having an acid dissociable, dissolution inhibiting group and a hydrophilic group as exemplified in the description of the component (A1) above is preferable. Specifically, a compound in which a part of hydrogen atoms of a hydroxyl group of a compound having a plurality of phenol skeletons is substituted with the acid dissociable, dissolution inhibiting group can be mentioned.
The component (A2) is, for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a sensitizer in a non-chemically amplified g-line or i-line resist or a heat resistance improver. Those substituted with a soluble dissolution inhibiting group are preferred and can be arbitrarily used.
Examples of such low molecular weight phenol compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyph Phenylmethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl- 4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, Examples include 2, 3, 4 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol or xylenol. Of course, it is not limited to these.
The acid dissociable, dissolution inhibiting group is not particularly limited, and examples thereof include those described above.

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

<(B) component>
The component (B) includes an acid generator (B1) (hereinafter sometimes referred to as the component (B1)) composed of the compound represented by the general formula (B1-1). The component (B1) is the same as the compound (B1) of the present invention.
(B1) A component can be used 1 type or in mixture of 2 or more types.
In the resist composition of the present invention, the content of the component (B1) in the component (B) is preferably 40% by mass or more, more preferably 70% by mass or more, and may be 100% by mass. Most preferably, it is 100 mass%. By being at least the lower limit of the range, lithography characteristics such as resolution, mask reproducibility, and line width roughness (LWR) are improved when a resist pattern is formed using the resist composition of the present invention.

In the component (B), an acid generator (B2) other than the component (B1) (hereinafter referred to as the component (B2)) may be used in combination with the component (B1).
The component (B2) is not particularly limited as long as it is other than the component (B1), 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、アリール基またはアルキル基を表し；式（ｂ’−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく；Ｒ^４”は、直鎖状、分岐鎖状または環状のアルキル基またはフッ素化アルキル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

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

In formula (b′-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group. In addition, any two of R ¹ ″ to R ³ ″ in formula (b′-1) may be bonded to each other to form a ring together with the sulfur atom in the formula.
Further, at least one of R ¹ ″ to R ³ ″ represents an aryl group. Of R ¹ ″ to R ³ ″, two or more are preferably aryl groups, and most preferably all R ¹ ″ to R ³ ″ are aryl groups.
The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups It may or may not be substituted with a group, a halogen atom, a hydroxyl group or the like. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is most preferred.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, Most preferred is a tert-butoxy group.
The alkoxy group that may be substituted for the hydrogen atom of the aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, and most preferably a methoxy group or an ethoxy group.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.
The alkyl group for R 1 ^{"~R 3",} is not particularly limited, for example, linear C1-10, branched or cyclic alkyl group, and the like. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
Among these, R ¹ ″ to R ³ ″ are most preferably a phenyl group or a naphthyl group, respectively.

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

R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group.
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 is a cyclic group as indicated by R ¹ ″ and preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and more preferably 6 carbon atoms. Most preferably, it is -10.
The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. The fluorination rate of the fluorinated alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. Particularly, all the hydrogen atoms are substituted with fluorine atoms. A fluorinated alkyl group (perfluoroalkyl group) is preferable because the strength of the acid is increased.
R ⁴ ″ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

In formula (b′-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferable that all of R ⁵ ″ to R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
"As ^{R 4} in formula (b'-1)" Formula (b'-2) ^{R 4} in the same groups as those described above for.

Specific examples of the onium salt acid generators represented by the formulas (b′-1) and (b′-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl). ) Iodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorobutanesulfonate, tri (4-methylphenyl) sulfonium trifluoromethanesulfonate, heptafluoropropanesulfonate Or its nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaf Oropropane sulfonate or its nonafluorobutane sulfonate, monophenyldimethylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; diphenyl monomethylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate Phonate, tri (4-tert-butyl) phenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, 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-methylpheny ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- I) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaf 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Examples thereof include sulfonate and its nonafluorobutanesulfonate; trifluoromethanesulfonate of 1- (4-methylphenyl) tetrahydrothiopyranium, its heptafluoropropanesulfonate and its nonafluorobutanesulfonate.
In addition, onium salts in which the anion portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

  Moreover, in the said general formula (b'-1) or (b'-2), the onium salt which replaced the anion part with the anion part represented by the following general formula (b'-3) or (b'-4) A system acid generator can also be used (the cation moiety is the same as (b′-1) or (b′-2)).

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

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

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

  A sulfonium salt having a cation moiety represented by the following general formula (b'-5) or (b'-6) can also be used as an onium salt acid generator.

［式中、Ｒ^４１”〜Ｒ^４６”はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_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 ⁴¹ ″ to R ⁴⁶ ″ each independently represents an alkyl group, an acetyl group, an alkoxy group, a carboxy group, a hydroxyl group, or a hydroxyalkyl group; n ₁ ″ to n ₅ ″ each independently represents 0 to Is an integer of 3, and n ₆ ″ is an integer of 0 to 2.]

In R ⁴¹ ″ to R ⁴⁶ ″, the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group, or an isopropyl group. , N-butyl group, or 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 ⁴¹ ″ to R ⁴⁶ ″ are integers of 2 or more, the plurality of R ⁴¹ ″ to R ⁴⁶ ″ may be the same or different. Good.
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.

The anion part of the sulfonium salt having a cation part represented by the formula (b′-5) or (b′-6) is not particularly limited, and the anion part of the onium salt acid generators proposed so far It may be similar. Examples of the anion moiety include fluorinated alkyl sulfones such as the anion moiety (R ^{4 ″} SO ₃ ⁻ ) of an onium salt acid generator represented by the general formula (b′-1) or (b′-2). Acid ion; anion moiety represented by the above general formula (b′-3) or (b′-4), etc. Among these, a fluorinated alkyl sulfonate ion is preferable, and fluorine having 1 to 4 carbon atoms. Alkyl sulfonate ions are more preferable, and linear perfluoroalkyl sulfonate ions having 1 to 4 carbon atoms are particularly preferable.Examples include trifluoromethyl sulfonate ions and heptafluoro-n-propyl sulfonate ions. , Nonafluoro-n-butyl sulfonate ion 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 (B2-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

（式（Ｂ２−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

(In formula (B2-1), 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 (B2-2) or (B2-3).

［式（Ｂ２−２）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 the formula (B2-2), 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（Ｂ２−３）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 the formula (B2-3), 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 (B2-2), the alkyl group or halogenated alkyl group having no substituent for 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 for 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 general formula (B2-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), WO2004 / 074242A2 (pages 65 to 85). The oxime sulfonate acid generators disclosed in Examples 1 to 40) of No. 1 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 (B2), one type of acid generator may be used alone, or two or more types may be used in combination.

  Content of (B) component in the resist composition of this invention is 0.5-30 mass parts with respect to 100 mass parts of (A) component, Preferably it is 1-20 mass parts. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<Optional component>
In the resist composition of the present invention, a nitrogen-containing organic compound (D) (hereinafter, (( D) component)) can be blended.
Since a wide variety of components (D) have already been proposed, any known one may be used. Among them, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are used. preferable. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, etc .; diethanolamine, triethanolamine, diisopropanolamine Triisopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine in which 3 alkyl groups having 5 to 10 carbon atoms are bonded to a nitrogen atom is preferable, and tri-n-pentylamine is most preferable.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

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.
(E) A component may be used individually by 1 type and may use 2 or more types together.
As the component (E), an organic carboxylic acid is preferable, and salicylic acid is particularly preferable.
(E) A component is used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

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

<Organic solvent (S)>
The resist composition of the present invention can be produced by dissolving the material in an organic solvent (S) (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone;
Ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone;
Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol;
Compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl ether, monopropyl of the polyhydric alcohols or the compound having an ester bond Derivatives of polyhydric alcohols such as ethers, monoalkyl ethers such as monobutyl ether or compounds having an ether bond such as monophenyl ether [in these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) Is preferred];
Cyclic ethers such as dioxane and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate;
Aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. be able to.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
The amount of the 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 2 -20% by mass, preferably 5-15% by mass.

≪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 The process of carrying out is included.
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 pre-baked (post-apply bake (PAB)) is performed at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 to This is applied for 90 seconds, and this is selectively exposed to ArF excimer laser light through a desired mask pattern using, for example, an ArF exposure apparatus, and then subjected to PEB (post-exposure heating) at a temperature of 80 to 150 ° C. It is applied for 120 seconds, preferably 60 to 90 seconds. Subsequently, this is developed using an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH), preferably rinsed with pure water and dried. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist pattern faithful to the mask pattern can be obtained.

The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC).

The wavelength used for 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 effective for KrF excimer laser, ArF excimer laser, EB or EUV, particularly ArF excimer laser.

The exposure of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be immersion exposure.
In immersion exposure, as described above, the portion between the lens, which has been conventionally filled with an inert gas such as air or nitrogen, and the resist film on the wafer is refracted larger than the refractive index of air. The exposure is performed in a state filled with a solvent having a high rate (immersion medium).
More specifically, the immersion exposure is a solvent (immersion medium) having a refractive index larger than the refractive index of air between the resist film obtained as described above and the lowermost lens of the exposure apparatus. And in that state, exposure can be performed through a desired mask pattern (immersion exposure).
As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film exposed by the immersion exposure is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.
Specific examples of the fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Examples thereof include liquids, and those having a boiling point of 70 to 180 ° C are 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.).

The resist composition of the present invention is a novel one that has not been conventionally known.
In addition, according to the resist composition of the present invention, a resist pattern having good lithography characteristics such as (for example, improvement in pattern shape, proximity effect, mask error factor) can be formed. The reason is not clear, but is presumed as follows.
In the resist composition of the present invention, the anion moiety of the component (B1) used as an acid generator is a polar group (—O—, —C (═O) — in the skeleton of “Y ¹ —SO ₃ ^— ”. Etc.) and a bulky group including Therefore, compared with the fluorinated alkyl sulfonate ion conventionally used as an anion, it has a high polarity, a three-dimensionally bulky and bulky structure. Conventional acid generators such as nonafluorobutanesulfonate, despite the relatively small carbon number of Y ¹ due to the interaction between molecules due to its high polarity and its bulky steric structure It is presumed that the diffusion of the anion portion (acid) in the resist film is suppressed as compared with the anion portion of the above, and as a result, the diffusion of the acid generated in the exposed region to the unexposed region is suppressed. Further, since the cation part of the component (B1) has a nitrogen atom, the component (B1) functions as a quencher that captures an acid in an unexposed area, and as a result, it is generated in the exposed area as described above. It is presumed that the diffusion of the acid into the unexposed area is further suppressed. It is presumed that these act synergistically to significantly improve the acid diffusion suppressing effect and improve lithography properties such as mask reproducibility.
For the same reason, an improvement in exposure margin (EL margin) is also expected. The EL margin is an exposure amount range in which a resist pattern can be formed with a dimension in which a deviation from a target dimension is within a predetermined range when exposure is performed with a different exposure amount, that is, a resist pattern faithful to a mask pattern is obtained. This is the range of the exposure amount, and the larger the EL margin value, the smaller the change amount of the pattern size accompanying the variation of the exposure amount, and the better the process margin.
In addition, the alkyl chain of Y ¹ alkylene group or fluorinated alkylene group has good decomposability, for example, perfluoroalkyl chain having 6 to 10 carbon atoms is hardly decomposable, considering bioaccumulation. The effect that it is safer in terms of handling can also be obtained.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
[Example 1]
A compound represented by the following chemical formula was synthesized by the following procedure.

Phosphorous oxide (8.53 g), 2,5-dimethylphenol (8.81 g) and diphenyl sulfoxide (12.2 g) were added in small portions to methanesulfonic acid (60.7 g) controlled at 15 to 20 ° C. After aging for 30 minutes while controlling the temperature at 15 to 20 ° C., the temperature was raised to 40 ° C. and aging was performed for 2 hours. Then, this reaction liquid was dripped at the pure water (109.35g) cooled to 10-15 degreeC. After completion of the dropwise addition, dichloromethane (54.68 g) was added, and after stirring, the dichloromethane layer was recovered.
In a separate container, hexane (386.86 g) at 20 to 25 ° C. was charged, and dichloromethane was added dropwise. After completion of the dropwise addition, the mixture was aged at 20 to 25 ° C. for 30 minutes, and then filtered to obtain the target compound (17.14 g) (yield 70.9%).
The obtained compound (hereinafter referred to as compound (1)) was analyzed by ¹ H-NMR. The results are shown below.
¹ H-NMR (solvent: DMSO-d6, 600 MHz): δ (ppm) = 7.61-7.72 (m, 10H, Phenyl), 7.14 (s, 2H, H ^c ), 3.12 ( s, 3H, H ^b ), 2.22 (s, 6H, H ^a ).
From the results described above, it was confirmed that the compound (1) had a structure shown below.

Next, the compound (1) (20.06 g) was dissolved in tetrahydrofuran (THF) (300.9 mL), and after dissolution was confirmed, 60% sodium hydride (5.18 g) was added under ice-cooling. Stir for 30 minutes. Thereafter, a solution of diethylcarbamic acid chloride (16.21 g) in THF (32.4 mL) was added. After reacting at 65 ° C. for 20 hours, pure water (300 g) was added to stop the reaction. Liquid separation was performed 3 times with 300 g (TBME) of tertbutyl methyl ether and pure water, and the aqueous phase was recovered and dried to obtain the target compound (25 g) (yield 82%, purity 76%). ).
The obtained compound (hereinafter referred to as compound (2)) was analyzed by ¹ H-NMR. The results are shown below.
¹ H-NMR (solvent: DMSO-d6, 400 MHz): δ (ppm) = 7.76-7.84 (m, 10H, Phenyl), 7.66 (s, 2H, H ^c ), 3.29- ^{3.47 (qq, 4H, H e} ), 2.32 (s, 3H, H b), 2.18 (s, 6H, H a), 1.09-1.25 (tt, 6H, H d ).
From the results described above, it was confirmed that the compound (2) had a structure shown below.

Separately, 6.7 ml of 1 tetrahydrofuran was added to 5.0 g of 2-naphthylmethyloxytetrafluoroethanesulfonyl fluoride, and an aqueous solution in which 0.98 g of lithium hydroxide was dissolved in 13.6 ml of pure water in an ice bath. It was dripped. Then, it stirred in the ice bath. It was confirmed that all of the sulfonyl fluoride groups were converted to lithium sulfonate due to the absence of ¹⁹ F-NMR absorption at −217.6 ppm by —SO ₂ F. Thereafter, the reaction solution was concentrated and dried to obtain a white viscous solid. The obtained crude product was dissolved in 14.2 ml of acetone, filtered to remove LiF as a by-product, and the filtrate was concentrated to give compound (3) 5 represented by the following chemical formula (3). .50 g was obtained.

Next, the compound (2) (4.9 g, purity 76%) was dissolved in pure water (70 g). Dichloromethane (70 g) was added thereto, and then compound (3) (3.0 g) was added little by little, followed by stirring at 25 ° C. for 1 hour. After completion of the reaction, the dichloromethane solution was washed with water and then concentrated to dryness. The obtained powder was dispersed and washed with hexane and then dried under reduced pressure to obtain the target compound (5.41 g) (yield 94%).
The obtained compound (hereinafter referred to as compound (b1-11)) was analyzed by ¹ H-NMR. The results are shown below.
¹ H-NMR (solvent: DMSO-d6, 400 MHz): δ (ppm) = 7.76-7.97 (m, 14H, Phenyl + Naptyl), 7.66 (s, 2H, H ^c ), 7.52- 7.55 (m, 3H, Naphtyl) , 5.20 (s, 3H, Naphtyl), 3.29-3.47 (qq, 4H, H e), 2.32 (s, 3H, H b), 2.18 (s, 6H, H ^a ), 1.09-1.25 (tt, 6H, H ^d ).
From the results above, it was confirmed that the compound (b1-11) had a structure shown below.

[Comparative Synthesis Example 1]
A compound represented by the following chemical formula was synthesized by the following procedure.

3 g of the compound (2) was dissolved in 47 g of pure water. To this was added 47 g of dichloromethane, and then 2.22 g of potassium perfluoro-n-butanesulfonate was added in small portions, followed by stirring at 25 ° C. for 1 hour. After completion of the reaction, the dichloromethane solution was washed with water and then concentrated to dryness. The obtained powder was dispersed and washed with hexane and then dried under reduced pressure to obtain 3.19 g of the target compound (yield 97.8%). Let the obtained compound be a compound (3).
The compound (3) was analyzed by ¹ H-NMR and ¹⁹ F-NMR. The results are shown below.
¹ H-NMR (solvent: DMSO-d6, 400 MHz): δ (ppm) = 7.76-7.97 (m, 10H, Phenyl), 7.66 (s, 2H, Hc), 3.29-3 .47 (qq, 4H, He), 2.18 (s, 6H, Ha), 1.09-1.25 (tt, 6H, Hd).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 77.7, −111.9, −118.5, −122.9.
From the results described above, it was confirmed that the compound (3) had a structure shown below.

[Example 2]
A compound represented by the following chemical formula was synthesized by the following procedure.

2,6-dimethylphenol (25.76 g) and acetone (500 g) were added to a three-necked flask, and potassium carbonate (145.6 g) was added thereto. After stirring for 30 minutes, 1-chloro-3-dimethylaminopropane (133.2 g) was added, potassium iodide (23.32 g) was further added, and the reaction was carried out for 19 hours under reflux of acetone. The reaction solution is cooled to room temperature, filtered, the obtained filtrate is dried, pure water (333 g) and TBME (tert-butyl-methyl ether, 333 g) are added to the obtained solid, and the solution is separated. Then, the TBME layer is recovered, further treated with a 10% HCl (92.8 g) aqueous solution, the aqueous layer is recovered by liquid separation, and washed twice with TBME (92.8 g). Next, a 10% NaOH (112.2 g) aqueous solution and TBME (92.8 g) are added, and the TBME layer is recovered by liquid separation, and washed with pure water (92.8 g) a total of four times. The obtained TBME layer was concentrated and dried with a vacuum pump to obtain the target compound (22.01) (yield 50.3%).
The obtained compound (hereinafter referred to as compound (4)) was analyzed by ¹ H-NMR. The results are shown below.
¹ H-NMR (solvent: DMSO-d6, 400 MHz): δ (ppm) = 1.85 (t, 2H, Hb), 2.03 to 2.78 (m, 6H, Ha, m, 6H, He) , 2.40 (m, 2H, Hc), 3.71 (t, 2H, Hd), 6.87 (t, 1H, Hg), 6.96 (d, 2H, Hf).
From the results shown above, it was confirmed that the compound (4) had a structure shown below.

Next, diphosphorus pentoxide (5.45 g) was added to methanesulfonic acid (43.0) with stirring, and compound (4) (9.55 g) and diphenylsulfoxide in methanesulfonic acid solution (28.28) were added thereto. 9 wt%, 26.9 g) is slowly added with ice cooling. Then, after stirring at room temperature for 18 hours, the reaction solution is slowly added dropwise to a mixed solvent of pure water (261.7 g) and TBME (523.5 g). The aqueous layer is collected by liquid separation, and the aqueous layer is washed 3 times with dichloromethane (523.5 g), and then a 30 wt% aqueous NaOH solution (136.6 g) is slowly added dropwise. Furthermore, after washing with TBME (136.6 g) for a total of 3 times, extraction with dichloromethane (398.3 g) was performed for a total of 3 times, and the resulting dichloromethane layer was concentrated to obtain the target compound as a viscous solid. (20.2 g) was obtained.
The obtained compound (hereinafter referred to as compound (5)) was analyzed by ¹ H-NMR.
¹ H-NMR (solvent: DMSO-d6, 400 MHz): δ (ppm) = 1.86 (t, 2H, Hb), 2.07-2.23 (m, 6H, Ha), 2.24-2 .35 (m, 6H, He, m, 3H, Hh), 2.40 (m, 2H, Hc), 3.87 (t, 2H, Hd), 7.60 (s, 2H, Hf), 7 .75-7.86 (m, 10H, Phenyl).
From the results shown above, it was confirmed that the compound (5) had a structure shown below.

Pure water (25.1 g) and dichloromethane (62.8 g) were added to 2-naphthylmethyloxytetrafluoroethanesulfonyl fluoride (3.70 g), and 16.6 wt% aqueous solution of compound (5) (37. 7 g) was added and stirred at room temperature for 2 hours. Thereafter, the organic layer was taken out by liquid separation, washed four times with pure water (62.8 g), and then the solvent was distilled off under reduced pressure to obtain the target compound (7.00 g).
The obtained compound (hereinafter referred to as compound (b1-12)) was analyzed by ¹ H-NMR and ¹⁹ F-NMR.
¹ H-NMR (solvent: DMSO-d6, 400 MHz): δ (ppm) = 1.86 (t, 2H, Hb), 2.12 (m, 6H, Ha), 2.27 (m, 6H, He ), 2.40 (m, 2H, Hc), 3.85 (t, 2H, Hd), 5.18 (s, 2H, Hh), 7.75-7.62 (m, 15H, Hh, Hi) ), 7.73-7.96 (m, 14H, Phenyl, Hj)
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 113.4 (t, 2F, Fa), −80.3 (t, 2F, Fb)
From the results above, it was confirmed that the compound (b1-12) had a structure shown below.

[Examples 3 to 5, Comparative Examples 1 to 3]
Each component shown in Table 1 was mixed and dissolved to prepare a positive resist composition.

(A) -1: Mw = 7000 and Mw / Mn = 1.8 represented by the following chemical formula (A) -1 (wherein l / m / n = 45/35/20 (molar ratio)) Polymer.
(B) -1: the above compound (b1-11).
(B) -2: Compound (3) above.
(B) -3: 4-Methylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate.
(B) -4: The above compound (b1-12).
(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(S) -1: Mixed solvent of PGMEA / PGME = 6: 4 (mass ratio).
(S) -2: γ-butyrolactone.
In addition, 10.32 mass parts of (B) -1, 9.79 mass parts of (B) -2, and 8.0 mass parts of (B) -3 are equimolar amounts.

  Using the obtained resist composition, a resist pattern was formed by the following procedure, and the lithography characteristics were evaluated.

[Resolution and sensitivity]
An organic antireflection film composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thus, an organic antireflection film having a film thickness of 82 nm was formed. Then, the positive resist compositions of Examples 3 to 5 and Comparative Examples 1 to 3 obtained above were applied on the antireflection film using a spinner, and 110 ° C. for 60 seconds on a hot plate. A pre-bake (PAB) process was performed under the conditions described above and dried to form a resist film having a thickness of 150 nm.
Next, an ArF excimer laser (193 nm) is applied to the resist film by an ArF exposure apparatus NSR-S302 (Nikon Corporation; NA (numerical aperture) = 0.60, 2/3 annular illumination) with a mask pattern (6 % Halftone).
Then, PEB treatment was performed at 110 ° C. for 60 seconds, and further alkali development was performed at 23 ° C. with a 2.38 mass% TMAH aqueous solution NMD-3 (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 30 seconds. Thereafter, water rinsing was performed using pure water for 30 seconds, followed by drying by shaking.
As a result, in each example, a line and space (LS) pattern having a line width of 120 nm and a pitch of 240 nm was formed on the resist film.
At this time, the optimum exposure dose Eop (mJ / cm ² ; sensitivity) at which a line and space pattern having a line width of 120 nm and a pitch of 240 nm was formed was determined. The results are shown in Table 2.

[Evaluation of resist pattern shape]
In the Eop, a trench pattern having a space width of 140 nm and a pitch of 1540 nm was formed as a target. The cross-sectional shape of the resist pattern at that time was observed with a scanning electron microscope S4500 (manufactured by Hitachi, Ltd.). The results were evaluated according to the following criteria and are shown in Table 2.
(Criteria)
○: The rectangularity is high.
Δ: Low rectangularity (pattern TOP is rounded).
[Proximity effect]
The proximity effect (nm) of the trench pattern was calculated by the following formula. The proximity effect (nm) is preferably as small as possible.
Proximity effect (nm) = trench pattern mask size (nm) −trench pattern space width (nm)
Then, when the proximity effect (nm) of Comparative Example 2 is used as a reference (when it is set to 100), the ratio (%) indicating how much the proximity effect of Example 2 and Comparative Example 1 is improved is expressed as the proximity effect ( %) Was calculated by the following formula. The results are shown in Table 2. In addition, it shows that the proximity effect was improved compared with the comparative example 2, so that the value of this proximity effect (%) is large.
Proximity effect (%) = 100+ [1- {Proximity effect in Example 2 or Comparative Example 1 (nm) / Proximity effect in Comparative Example 2 (nm)} × 100]

[Mask error factor (MEF)] 120 of 1: 1.2, 130 of 1: 1
In each Eop of Examples 4 and 5 and Comparative Example 2, LS patterns with a pitch of 240 nm were formed using mask patterns with target sizes of 120 nm and 130 nm, respectively. At this time, the slope of the straight line when the target size (nm) was plotted on the horizontal axis and the line width (nm) of the LS pattern formed on the resist film using each mask pattern was plotted on the vertical axis was calculated as MEF. MEF (straight line) means that the closer the value is to 1, the better the mask reproducibility. The obtained results are shown in Table 2.

  From the above results, it was confirmed that when the compound of the present invention was used, the lithography properties were excellent.

Claims (12)

A resist composition containing a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component (B) that generates an acid upon irradiation with radiation,
The acid generator component (B) contains an acid generator (B1) composed of a compound represented by the following general formula (B1-1).

[Wherein, R ^x is an optionally substituted aromatic hydrocarbon group ; Q ¹ is an optionally substituted alkylene group having 1 to 12 carbon atoms or a single bond. N is 0 or 1; Y ¹ is an alkylene group having 1 to 4 carbon atoms or a fluorinated alkylene group; A ⁺ is an organic cation containing a nitrogen atom; ] The resist composition according to claim 1, wherein A ⁺ in the general formula (B1-1) has a group represented by the following general formula (I).

[Wherein, W ¹ is an oxygen atom or a sulfur atom; Q ² is an alkylene group or a single bond; R ⁷ and R ⁸ are each independently a hydrogen atom or an alkyl group optionally having a substituent. , An aliphatic cyclic group that may have a substituent, or an aromatic cyclic group that may have a substituent, and R ⁷ and R ⁸ are bonded to each other to form a ring Also good. ] The resist composition according to claim 1 or 2, wherein the acid generator (B1) comprises a compound represented by the following general formula (B1-1-1).

[Wherein, R ^x , Q ¹ , n, and Y ¹ are the same as described above; R ^{1 to} R ³ each independently have an aryl group that may have a substituent, or a substituent. And at least one of R ^{1 to} R ³ is an aryl group, and at least one of R ^{1 to} R ³ is a substituent represented by the following general formula (I-1) Has a group. Alternatively, R ¹ and R ² are bonded to each other to form a ring together with the sulfur atom in the formula, and R ³ is an aryl group which may have a substituent, or an alkyl which may have a substituent. Group, or —R ⁴ —C (═O) —R ⁵ (wherein R ⁴ is an alkylene group having 1 to 5 carbon atoms, and R ⁵ is an aryl group which may have a substituent). And one or both of the ring and R ³ have a substituent represented by the following general formula (I-1). ]

[Wherein, W ¹ , Q ² , R ⁷ and R ⁸ are the same as defined above, and W ² is a divalent linking group. d is 0 or 1. ]   The resist composition according to any one of claims 1 to 3, wherein the base material component (A) is a base material component whose solubility in an alkali developer is increased by the action of an acid.   The base material component (A) contains a resin component (A1) whose solubility in an alkaline developer is increased by the action of an acid, and the resin component (A1) contains an acid dissociable, dissolution inhibiting group. The resist composition according to claim 4, comprising a structural unit (a1) derived from   The resist composition according to claim 5, wherein the resin component (A1) further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.   The resist composition according to claim 5 or 6, wherein the resin component (A1) further has a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.   Using the resist composition according to any one of claims 1 to 7, a step of forming a resist film on a support, 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. The compound represented by the following general formula (B1-1).

[Wherein, R ^x is an optionally substituted aromatic hydrocarbon group ; Q ¹ is an optionally substituted alkylene group having 1 to 12 carbon atoms or a single bond. N is 0 or 1; Y ¹ is an alkylene group having 1 to 4 carbon atoms or a fluorinated alkylene group; A ⁺ is an organic cation containing a nitrogen atom; ] The compound according to claim 9, wherein A ⁺ in the general formula (B1-1) has a group represented by the following general formula (I).

[Wherein, W ¹ is an oxygen atom or a sulfur atom; Q ² is an alkylene group or a single bond; R ⁷ and R ⁸ are each independently a hydrogen atom or an alkyl group optionally having a substituent. , An aliphatic cyclic group that may have a substituent, or an aromatic cyclic group that may have a substituent, and R ⁷ and R ⁸ are bonded to each other to form a ring Also good. ] The compound of Claim 9 or 10 represented by the following general formula (B1-1-1).

[Wherein, R ^x , Q ¹ , n, and Y ¹ are the same as described above; R ^{1 to} R ³ each independently have an aryl group that may have a substituent, or a substituent. And at least one of R ^{1 to} R ³ is an aryl group, and at least one of R ^{1 to} R ³ is a substituent represented by the following general formula (I-1) Has a group. Alternatively, R ¹ and R ² are bonded to each other to form a ring together with the sulfur atom in the formula, and R ³ is an aryl group which may have a substituent, or an alkyl which may have a substituent. Group, or —R ⁴ —C (═O) —R ⁵ (wherein R ⁴ is an alkylene group having 1 to 5 carbon atoms, and R ⁵ is an aryl group which may have a substituent). And one or both of the ring and R ³ have a substituent represented by the following general formula (I-1). ]

[Wherein, W ¹ , Q ² , R ⁷ and R ⁸ are the same as defined above, and W ² is a divalent linking group. d is 0 or 1. ]   The acid generator which consists of a compound as described in any one of Claims 9-11.