JP2009167156A - New compound and its production method, acid-generating agent, resist composition and resist pattern-forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new compound useful as an acid-generating agent for a resist composition, its production method, an acid-generating agent, a resist composition and a resist pattern-forming method. <P>SOLUTION: The resist composition comprises a base material component (A) which changes solubility in an alkaline developing liquid by an action of an acid and an acid-generating agent component (B) generating an acid on exposure to light, where the acid-generating agent component (B) comprises an acid-generating agent (B1) composed of a compound represented by general formula (b1-1). In the formula, R<SP>X</SP>is an aliphatic group optionally bearing a substituent group (provided that a nitrogen atom is excluded); R<SP>1</SP>is an alkylene group; Y<SP>1</SP>is an alkylene or fluorinated alkylene group having 1-4 carbon atoms; and Z<SP>+</SP>is an organic cation (provided that an ion represented by general formula (w-1) is excluded). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed with radiation such as light or an electron beam, and subjected to a development process, whereby the resist A step of forming a resist pattern having a predetermined shape on the film is performed. A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has rapidly progressed 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.
Along with the shortening of the wavelength of the exposure light source, the resist material is required to be improved in lithography characteristics such as sensitivity to the exposure light source and resolution capable of reproducing a pattern with a fine dimension. As a resist material satisfying such requirements, a chemically amplified resist containing a base material component whose solubility in an alkaline developer is changed by the action of an acid and an acid generator component that generates an acid upon exposure is known. Yes.
Conventionally, a resin is mainly used as a base component of such a chemically amplified resist. For example, polyhydroxystyrene (PHS) or a resin in which a part of its hydroxyl group is protected with an acid dissociable, dissolution inhibiting group, etc. A PHS resin, a copolymer derived from (meth) acrylic acid ester, a resin in which a part of its carboxy group is protected with an acid dissociable, dissolution inhibiting group, and the like are used.
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 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 (for example, patent documents). 1).
JP 2003-241385 A

As onium salt acid generators as described above, those having perfluoroalkylsulfonic acid ions as anion parts (acids) are generally used at present.
However, such an onium salt-based acid generator has a low affinity for an alkali developer due to its structure, and the distribution within the resist film is difficult to be uniform, which adversely affects lithography properties such as resolution. There is a risk of giving.
The perfluoroalkyl chain in the anion moiety is preferably longer in order to suppress the diffusion of the acid after exposure, but the perfluoroalkyl chain having 6 to 10 carbon atoms is hardly decomposable. Therefore, perfluoroalkyl sulfonate ions having 4 or less carbon atoms, such as nonafluorobutane sulfonate ions, are used for the safety of handling considering bioaccumulation.
Therefore, there is a need for an onium salt compound having an anion moiety that is more useful as an acid generator for resist compositions.
The present invention has been made in view of the above circumstances, and provides a novel compound useful as an acid generator for a resist composition, a method for producing the same, an acid generator, a resist composition, and a method for forming a resist pattern. For the purpose.

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 changes 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（ただし、窒素原子は除く。）を有していてもよい脂肪族基であり；Ｒ^１はアルキレン基であり；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；Ｚ^＋は有機カチオン（ただし下記一般式（ｗ−１）で表されるイオンを除く。）である。］

[Wherein, R ^X is an aliphatic group which may have a substituent (excluding a nitrogen atom); R ¹ is an alkylene group; Y ¹ is an alkylene group having 1 to 4 carbon atoms] Or it is a fluorinated alkylene group; Z ^<+> is an organic cation (however, the ion represented by the following general formula (w-1) is remove | excluded). ]

［式中、Ｒ^３〜Ｒ^６はそれぞれ独立に水素原子、または置換基を有していてもよい炭化水素基であり、Ｒ^３〜Ｒ^６のうちの少なくとも１つは前記炭化水素基であり、Ｒ^３〜Ｒ^６のうちの少なくとも２つがそれぞれ結合して環を形成していてもよい。］

[Wherein, R ^{3 to} R ⁶ are each independently a hydrogen atom or an optionally substituted hydrocarbon group, and at least one of R ^{3 to} R ⁶ is the hydrocarbon group. , R ^{3 to} R ⁶ may be bonded to each other to form a ring. ]

  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 development of the resist film. A resist pattern forming method including a step of forming a resist pattern.

  The third aspect of the present invention is a compound represented by the following general formula (b1-1) (hereinafter referred to as compound (b1-1)).

［式中、Ｒ^Ｘは置換基（ただし、窒素原子は除く。）を有していてもよい脂肪族基であり；Ｒ^１はアルキレン基であり；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；Ｚ^＋は有機カチオン（ただし下記一般式（ｗ−１）で表されるイオンを除く。）である。］

[Wherein, R ^X is an aliphatic group which may have a substituent (excluding a nitrogen atom); R ¹ is an alkylene group; Y ¹ is an alkylene group having 1 to 4 carbon atoms] Or it is a fluorinated alkylene group; Z ^<+> is an organic cation (however, the ion represented by the following general formula (w-1) is remove | excluded). ]

［式中、Ｒ^３〜Ｒ^６はそれぞれ独立に水素原子、または置換基を有していてもよい炭化水素基であり、Ｒ^３〜Ｒ^６のうちの少なくとも１つは前記炭化水素基であり、Ｒ^３〜Ｒ^６のうちの少なくとも２つがそれぞれ結合して環を形成していてもよい。］

[Wherein, R ^{3 to} R ⁶ are each independently a hydrogen atom or an optionally substituted hydrocarbon group, and at least one of R ^{3 to} R ⁶ is the hydrocarbon group. , R ^{3 to} R ⁶ may be bonded to each other to form a ring. ]

  In a fourth aspect of the present invention, a compound (b0-01) represented by the following general formula (b0-01) is reacted with a compound (b0-02) represented by the following general formula (b0-02). Is a method for producing a compound comprising a step of obtaining a compound (b1-1) represented by the following general formula (b1-1) (hereinafter referred to as a method for producing the compound (b1-1)).

［式中、Ｒ^Ｘは置換基（ただし、窒素原子は除く。）を有していてもよい脂肪族基であり；Ｒ^１はアルキレン基であり；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；Ｗ^＋はアルカリ金属イオンまたは下記一般式（ｗ−１）で表されるイオンであり；Ｚ^＋は有機カチオン（ただし下記一般式（ｗ−１）で表されるイオンを除く。）であり、Ａ⁻は非求核性アニオンである。］

[Wherein, R ^X is an aliphatic group which may have a substituent (excluding a nitrogen atom); R ¹ is an alkylene group; Y ¹ is an alkylene group having 1 to 4 carbon atoms] Or a fluorinated alkylene group; W ⁺ is an alkali metal ion or an ion represented by the following general formula (w-1); Z ⁺ is an organic cation (however, represented by the following general formula (w-1)) And A ⁻ is a non-nucleophilic anion. ]

［式中、Ｒ^３〜Ｒ^６はそれぞれ独立に水素原子、または置換基を有していてもよい炭化水素基であり、Ｒ^３〜Ｒ^６のうちの少なくとも１つは前記炭化水素基であり、Ｒ^３〜Ｒ^６のうちの少なくとも２つがそれぞれ結合して環を形成していてもよい。］

[Wherein, R ^{3 to} R ⁶ are each independently a hydrogen atom or an optionally substituted hydrocarbon group, and at least one of R ^{3 to} R ⁶ is the hydrocarbon group. , R ^{3 to} R ⁶ may be bonded to each other to form a ring. ]

  A fifth aspect of the present invention is an acid generator comprising the compound of the third aspect.

In the present specification and claims, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.
“Structural unit” means a monomer unit (monomer unit) constituting a resin component (polymer).
“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, its manufacturing method, an acid generator, a resist composition, and a resist pattern formation method can be provided.

<< Compound (b1-1) >>
First, the compound (b1-1) which is a 3rd aspect of this invention is demonstrated. The compound (b1-1) is suitably used as an acid generator for the resist composition which is the first aspect of the present invention.
In formula (b1-1), examples of the aliphatic group represented by R ^x include an aliphatic hydrocarbon group which may have a substituent. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In R ^x , in the aliphatic hydrocarbon group, a part of carbon atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom (excluding a nitrogen atom). A part or all of the hydrogen atoms constituting the group hydrocarbon group may be substituted with a substituent containing a hetero atom (excluding a nitrogen atom).
The “heteroatom” in R ^x is not particularly limited as long as it is an atom other than a carbon atom, a hydrogen atom and a nitrogen atom, and examples thereof include a halogen atom, an oxygen atom and a sulfur atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom (excluding a nitrogen atom) may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. _{-, - S -, - S} (= O) 2 -, - S (= O) 2 -O- , and the like. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent that substitutes part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

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

As an unsaturated hydrocarbon group, C2-C5 is preferable, 2-4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the unsaturated hydrocarbon group is particularly preferably a propenyl group.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms are removed from a monocycloalkane; a group in which one or more hydrogen atoms are removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
When the aliphatic cyclic group does not contain a substituent containing a hetero atom in the ring structure, the aliphatic cyclic group is preferably a polycyclic group, and has one or more hydrogen atoms from the polycycloalkane. Excluded groups are preferred, and groups obtained by removing one or more hydrogen atoms from adamantane are most preferred.
When the aliphatic cyclic group includes a substituent containing a hetero atom in the ring structure, examples of the substituent containing a hetero atom include —O—, —C (═O) —O—, —S—. , —S (═O) ₂ — and —S (═O) ₂ —O— are preferable. Specific examples of the aliphatic cyclic group include the following formulas (L1) to (L5), (S1) to (S4), and the like.

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

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

As the alkylene group for Q ″, the same alkylene groups as those described above for R ¹ can be used.
As the alkylene group for R ⁹⁴ and R ^95, the same alkylene groups as those described above for R ¹ can be used.
In these aliphatic cyclic groups, a part of hydrogen atoms bonded to carbon atoms constituting the ring structure may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
As said alkyl group, a C1-C5 alkyl group is preferable, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, n-butyl group, and a tert- butyl group.
Examples of the alkoxy group and the halogen atom are the same as those exemplified as the substituent for substituting part or all of the hydrogen atoms.

In the present invention, R ^X is particularly preferably a linear alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, the above (L2) to (L5), (S3) to (S4), etc. An adamantyl group is preferred.
As the linear alkyl group which may have a substituent, those having an aliphatic cyclic group as a substituent are preferable. Here, examples of the aliphatic cyclic group include the same groups as those described above. In the present invention, R ^X is more preferably a linear alkyl group having a polycyclic aliphatic cyclic group as a substituent, and a linear alkyl group having an adamantyl group as a substituent. More preferably it is.

The alkylene group for R ¹ may be linear, branched or cyclic, preferably linear or branched, and more preferably linear.
1-12 are preferable, as for carbon number of a linear or branched alkylene group, 1-5 are more preferable, and 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. Among these, a methylene group, an ethylene group or an n-propylene group is preferable, and an ethylene group is particularly preferable.

Y ¹ is an alkylene group having 1 to 4 carbon atoms or a fluorinated alkylene group.
Examples of the alkylene group for Y ¹ include the same alkylene groups as those described above for R ¹ having 1 to 4 carbon atoms. Examples of the fluorinated alkylene group include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^1, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH _{(CH 3) -, - C} (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

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

The organic cation of Z ⁺ is not particularly limited as long as it is other than the ion represented by the general formula (w-1), and conventionally known as the cation part of the onium salt acid generator. It can be used as appropriate. Among these cation moieties, as the organic cation of Z ⁺ , a sulfonium ion or an iodonium ion is preferable, and a sulfonium ion is particularly preferable.
Specifically, a cation moiety represented by the following general formula (b′-1), (b′-2), (b-5) or (b-6) can be preferably used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；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^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; any two of R ¹ ″ to R ³ ″ are bonded to each other. ^May form a ring together with the sulfur atom in the formula; at least one of R ¹ ″ to R ³ ″ represents an aryl group, and at least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. To express. ]

［式中、Ｒ^４０は水素原子またはアルキル基であり、Ｒ^４１はアルキル基、アセチル基、カルボキシ基、またはヒドロキシアルキル基であり、Ｒ^４２〜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、またはヒドロキシアルキル基であり；ｎ_０〜ｎ_５はそれぞれ独立して０〜３の整数であり、ただし、ｎ_０＋ｎ_１は５以下であり、ｎ_６は０〜２の整数である。］

[Wherein, R ⁴⁰ represents a hydrogen atom or an alkyl group, R ⁴¹ represents an alkyl group, an acetyl group, a carboxy group, or a hydroxyalkyl group, and R ^{42 to} R ⁴⁶ each independently represents an alkyl group, an acetyl group, An alkoxy group, a carboxy group, or a hydroxyalkyl group; n _{0 to} n ₅ are each independently an integer of 0 to 3, provided that n ₀ + n ₁ is 5 or less and n ₆ is 0 to 2 It is an integer. ]

In formula (b′-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group. Any two of R ¹ ″ to R ³ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula.
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 examples thereof include an unsubstituted aryl group having 6 to 20 carbon atoms, a part or all of hydrogen atoms of the unsubstituted aryl group being an alkyl group, alkoxy group, an alkoxyalkyl group, an alkoxycarbonylalkyl group, a halogen atom, substituted substituted aryl group such as a hydroxyl group, - (R ⁴ ') include ^{-C (= O) -R 5'} . R ⁴ ′ is an alkylene group having 1 to 5 carbon atoms. R ⁵ ′ is an aryl group. As the aryl group for R ⁵ ′, the same aryl groups as those described above for R ¹ ″ to R ³ ″ can be used.
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 ^R49 is an alkyl group.
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 aryl groups for R ¹ ″ to R ³ ″ are each preferably a phenyl group or a naphthyl group.

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.

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

  Specific examples of the cation moiety represented by the formula (b′-1) include triphenylsulfonium, (3,5-dimethylphenyl) diphenylsulfonium, (4- (2-adamantoxymethyloxy) -3,5- Dimethylphenyl) diphenylsulfonium, (4- (2-adamantoxymethyloxy) phenyl) diphenylsulfonium, (4- (tert-butoxycarbonylmethyloxy) phenyl) diphenylsulfonium, (4- (tert-butoxycarbonylmethyloxy)- 3,5-dimethylphenyl) diphenylsulfonium, (4- (2-methyl-2-adamantyloxycarbonylmethyloxy) phenyl) diphenylsulfonium, (4- (2-methyl-2-adamantyloxycarbonylmethyloxy) -3, 5-dimethyl Enyl) diphenylsulfonium, tri (4-methylphenyl) sulfonium, dimethyl (4-hydroxynaphthyl) sulfonium, monophenyldimethylsulfonium, diphenylmonomethylsulfonium, (4-methylphenyl) diphenylsulfonium, (4-methoxyphenyl) diphenylsulfonium, Tri (4-tert-butyl) phenylsulfonium, diphenyl (1- (4-methoxy) naphthyl) sulfonium, di (1-naphthyl) phenylsulfonium, 1-phenyltetrahydrothiophenium, 1- (4-methylphenyl) tetrahydro Thiophenium, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium, 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium 1- (4-ethoxynaphthalen-1-yl) tetrahydrothiophenium, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium, 1-phenyltetrahydrothiopyranium, 1- (4-hydroxy Phenyl) tetrahydrothiopyranium, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiopyranium, 1- (4-methylphenyl) tetrahydrothiopyranium and the like.

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. All of R ⁵ ″ to R ⁶ ″ are preferably 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.

  Specific examples of the cation moiety represented by the formula (b′-2) include diphenyliodonium and bis (4-tert-butylphenyl) iodonium.

In R ^{40 to} R ⁴⁶ in the general formulas (b-5) to (b-6), the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a linear or branched alkyl group. , Methyl group, ethyl group, propyl group, 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 sign n ₀ attached to the OR ⁴⁰ is an integer of 2 or more, the plurality of OR ⁴⁰ ″ may be the same or different.
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.
n ₀ is preferably 0 or 1.
n ₁ is preferably 0-2.
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.

Z ⁺ is preferably a cation moiety represented by the formula (b′-1) or (b-5), and in particular, the following formulas (b′-1-1) to (b′-1-10), ( b-5-1) to cation moieties represented by (b-5-4) are preferred, and triions such as cation moieties represented by formulas (b′-1-1) to (b′-1-8) are preferred. The cation part of a phenyl skeleton or the cation part represented by (b′-1-10) is more preferable.
In formulas (b′-1-9) to (b′-1-10), R ⁸ and R ⁹ are each independently a phenyl group, a naphthyl group, or a carbon number of 1 to 1 which may have a substituent. 5 is an alkyl group, an alkoxy group, or a hydroxyl group, preferably a phenyl group which may have a substituent.
u is an integer of 1 to 3, and 1 or 2 is most preferable.

  As the compound (b1-1), compounds represented by the following general formulas (b1-1-11) to (b1-1-13) are particularly preferable.

［式中、Ｚ^＋は前記と同じであり、ｐは１〜３の整数であり、ｑ１〜ｑ３はそれぞれ独立に１〜１２の整数であり、ｒ１は０〜３の整数であり、ｇは１〜２０の整数であり、Ｒ^７は置換基である。］

[Wherein Z ⁺ is the same as defined above, p is an integer of 1 to 3, q1 to q3 are each independently an integer of 1 to 12, r1 is an integer of 0 to 3, and g is 20 is an integer, ^{R 7} is a substituent. ]

Examples of the substituent for R ⁷ include the same groups as those described above as the substituent that the aliphatic hydrocarbon group may have in R ^x .
If signs placed R ⁷ (r1) is an integer of 2 or more, a plurality of the R ⁷ groups may be the same, respectively, it may be different.
p is preferably 1 or 2.
q1 to q3 are each independently preferably 1 to 5, and more preferably 1 to 3.
r1 is preferably an integer of 0 to 2, and more preferably 0 or 1.
g is preferably 1 to 15, and more preferably 1 to 10.

The compound (b1-1) of the present invention is a novel compound.
The compound (b1-1) of the present invention is useful as an acid generator for a chemically amplified resist composition, and can be blended as an acid generator in a chemically amplified resist composition.

  Although the manufacturing method of the compound (b0-1) of this invention is not specifically limited, For example, it can manufacture with the manufacturing method of the following compound (b1-1) of this invention.

<< Method for Producing Compound (b1-1) >>
The production method of the compound (b1-1) according to the fourth aspect of the present invention is represented by the compound (b0-01) represented by the following general formula (b0-01) and the following general formula (b0-02). A step of obtaining a compound (b1-1) by reacting with the compound (b0-02) to be produced.

［式中、Ｒ^Ｘは置換基（ただし、窒素原子は除く。）を有していてもよい脂肪族基であり；Ｒ^１はアルキレン基であり；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；Ｗ^＋はアルカリ金属イオンまたは下記一般式（ｗ−１）で表されるイオンであり；Ｚ^＋は有機カチオン（ただし下記一般式（ｗ−１）で表されるイオンを除く。）であり、Ａ⁻は非求核性アニオンである。］

[Wherein, R ^X is an aliphatic group which may have a substituent (excluding a nitrogen atom); R ¹ is an alkylene group; Y ¹ is an alkylene group having 1 to 4 carbon atoms] Or a fluorinated alkylene group; W ⁺ is an alkali metal ion or an ion represented by the following general formula (w-1); Z ⁺ is an organic cation (however, represented by the following general formula (w-1)) And A ⁻ is a non-nucleophilic anion. ]

［式中、Ｒ^３〜Ｒ^６はそれぞれ独立に水素原子、または置換基を有していてもよい炭化水素基であり、Ｒ^３〜Ｒ^６のうちの少なくとも１つは前記炭化水素基であり、Ｒ^３〜Ｒ^６のうちの少なくとも２つがそれぞれ結合して環を形成していてもよい。］

[Wherein, R ^{3 to} R ⁶ are each independently a hydrogen atom or an optionally substituted hydrocarbon group, and at least one of R ^{3 to} R ⁶ is the hydrocarbon group. , R ^{3 to} R ⁶ may be bonded to each other to form a ring. ]

In the formula, R ^X , R ¹ , Y ¹ and Z ⁺ are the same as defined above.
W ⁺ is an alkali metal ion or an ion represented by the general formula (w-1) (hereinafter referred to as a substituted ammonium ion).
In W ⁺ , examples of alkali metal ions include sodium ions, potassium ions, lithium ions, and the like.

In formula (w-1), R ^{3 to} R ⁶ are each independently a hydrogen atom or a hydrocarbon group which may have a substituent, and at least one of R ^{3 to} R ⁶ is the carbonization It is a hydrogen group.
As a hydrocarbon group in R < ³ > -R < ⁶ >, the same thing as said R ^<X > is mentioned.
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. When the hydrocarbon group is an aliphatic hydrocarbon group, the aliphatic hydrocarbon group is particularly preferably an alkyl group having 1 to 12 carbon atoms which may have a substituent.
Examples of the substituent that the hydrocarbon group may have are the same as those described as the substituent that the hydrocarbon group of R ^X may have, and a hydroxyl group is particularly preferable. Also, a substituent containing a nitrogen atom, such as nitrogen atom, a cyano group (-CN), amino group _(-NH 2), amido (-NH-C (= O) -) and the like may be included.
It is preferable that at least one of R ^{3 to} R ⁶ is the hydrocarbon group, and two or three are the hydrocarbon groups.

At least two of R ^{3 to} R ⁶ may be bonded to each other to form a ring. For example, two of R ^{3 to} R ⁶ may be bonded to form one ring, or three of R ^{3 to} R ⁶ may be bonded to form a ring, Two of R ^{3 to} R ⁶ may be bonded to each other to form two rings.
The ring (heterocycle containing a nitrogen atom as a heteroatom) formed by combining at least two of R ^{3 to} R ⁶ with the nitrogen atom in the formula may be an aliphatic heterocycle or aromatic. It may be a heterocyclic ring. The heterocyclic ring may be monocyclic or polycyclic.

Specific examples of substituted ammonium ions include ammonium ions derived from amines.
Here, “ammonium ion derived from amine” means a cation formed by bonding a hydrogen atom to a nitrogen atom of an amine, and a quaternary ammonium having one substituent further bonded to the nitrogen atom of the amine. Ion.
The amine for deriving the ammonium ion may be an aliphatic amine or an aromatic amine.
As the aliphatic amine, 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 having 12 or less carbon atoms or a hydroxyalkyl group is particularly preferable.
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.
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.
Aromatic amines include aniline, pyridine, 4-dimethylaminopyridine (DMAP), pyrrole, indole, pyrazole, imidazole and the like.
Examples of the quaternary ammonium ion include tetramethylammonium ion, tetraethylammonium ion, and tetrabutylammonium ion.

In the present invention, the substituted ammonium ion is particularly preferably one in which at least one of R ^{3 to} R ⁶ is an alkyl group and at least one is a hydrogen atom.
Among them, three of R ^{3 to} R ⁶ are alkyl groups and the remaining one is a hydrogen atom (trialkylammonium ion), or two of R ^{3 to} R ⁶ are alkyl groups, In addition, those in which the remaining two are hydrogen atoms (dialkylammonium ions) are preferred.
The alkyl group in the trialkylammonium ion or dialkylammonium ion preferably independently has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 5 carbon atoms. Specific examples 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. Of these, the ethyl group is most preferred.

A ⁻ is a non-nucleophilic anion.
Examples of the non-nucleophilic ion include halogen ions such as bromine ion and chlorine ion, ions that can be acid having lower acidity than the compound (b0-01), BF ₄ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , PF ₆ ^- or ClO ₄ ^- and the like.
Examples of ions that can be an acid having a lower acidity than the compound (b0-01) in A ⁻ include sulfonate ions such as p-toluenesulfonate ion, methanesulfonate ion, benzenesulfonate ion, and trifluoromethanesulfonate ion. Is mentioned.

  Compound (b0-01) includes, for example, a compound (1-3) represented by the following general formula (1-3) and a compound (2-1) represented by the following general formula (2-1). It can be synthesized by reacting.

［式中、Ｒ^Ｘ、Ｒ^１、Ｙ^１、Ｗ^＋はそれぞれ前記と同じであり、Ｘ^２２はハロゲン原子である。］

[Wherein, R ^X , R ¹ , Y ¹ , W ⁺ are the same as defined above, and X ²² is a halogen atom. ]

Examples of the halogen atom for X ²² include a bromine atom, a chlorine atom, an iodine atom, a fluorine atom, and the like. From the viewpoint of excellent reactivity, a bromine atom or a chlorine atom is preferable, and a chlorine atom is particularly preferable.

Compounds (1-3) and (2-1) may be commercially available or synthesized.
For example, when W ⁺ in the compound (1-3) is an alkali metal ion, a preferred synthesis method of the compound (the compound (1-3 ′) represented by the following general formula (1-3 ′)) is The compound (1-1) represented by the formula (1-1) and the compound (1-2) represented by the following general formula (1-2) are reacted to obtain the compound (1-3 ′). The method which has a process is mentioned.

［式中、Ｒ^１、Ｙ^１はそれぞれ前記と同じであり、Ｒ^２は、置換基として芳香族基を有していてもよい脂肪族基であり、Ｍ^＋はアルカリ金属イオンである。］

[Wherein, R ¹ and Y ¹ are the same as defined above, R ² is an aliphatic group which may have an aromatic group as a substituent, and M ⁺ is an alkali metal ion. ]

Examples of M ⁺ include the same alkali metal ions as those described above for W ⁺ .
R ² is an aliphatic group that may have an aromatic group as a substituent.
The aliphatic group may be a saturated aliphatic group or an unsaturated aliphatic group. The aliphatic group may be linear, branched or cyclic, or a combination thereof.
The aliphatic group may be an aliphatic hydrocarbon group consisting of only a carbon atom and a hydrogen atom, and a group in which a part of carbon atoms constituting the aliphatic hydrocarbon group is substituted with a substituent containing a hetero atom It may be a group in which part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group are substituted with a substituent containing a hetero atom.
The hetero atom is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed only of a hetero atom, or may be a group containing a group or atom other than a hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. —, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, — S (= O) ₂ —O— and the like can be mentioned. When the aliphatic group includes a cyclic group, these substituents may be included in the ring structure of the cyclic group.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include, for example, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ⁹⁶ , —OC (═O). R ⁹⁷ , a cyano group and the like can be mentioned.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.
R ⁹⁶ and R ⁹⁷ are each independently a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms.
When the alkyl group in R ⁹⁶ and R ⁹⁷ is linear or branched, the carbon number thereof is preferably 1 to 10, more preferably 1 to 5, and further preferably 1 or 2. Specific examples thereof include the same as the linear or branched monovalent saturated hydrocarbon group described later.
When the alkyl group in R ⁹⁶ and R ⁹⁷ is cyclic, the ring may be monocyclic or polycyclic. The carbon number is preferably 3 to 15, more preferably 4 to 12, and still more preferably 5 to 10. Specifically, the same thing as the cyclic | annular monovalent | monohydric saturated hydrocarbon group mentioned later is mentioned.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group having 1 to 30 carbon atoms, a linear or branched monovalent unsaturated hydrocarbon group having 2 to 10 carbon atoms, Or a C3-C30 cyclic aliphatic hydrocarbon group (aliphatic cyclic group) is preferable.
The linear saturated hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched saturated hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

As an unsaturated hydrocarbon group, C2-C5 is preferable, 2-4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the unsaturated hydrocarbon group is particularly preferably a propenyl group.

  The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. Specifically, for example, a group in which one or more hydrogen atoms have been removed from a monocycloalkane; a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.

In R ² , the aliphatic group may have an aromatic group as a substituent.
Aromatic groups include aryl groups 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, and a phenanthryl group. Group; a heteroaryl group in which part of the carbon atoms constituting the ring of these aryl groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom;
These aromatic groups may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxy group, a hydroxyl group, or a halogen atom. 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. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom, and a fluorine atom is preferable.
In addition, when R ² in the compound (1-1) is an aromatic group, that is, an oxygen atom adjacent to R ² is directly bonded to an aromatic ring without an aliphatic group, the compound (1- The reaction between 1) and compound (1-2) does not proceed, and compound (1-3) cannot be obtained.

Compounds (1-1) and (1-2) may be commercially available, or may be synthesized using a known method.
For example, the compound (1-2) is a compound represented by the following general formula (0-2) by heating and neutralizing the compound (0-1) represented by the following general formula (0-1) in the presence of an alkali. A step of obtaining the represented compound (0-2) (hereinafter referred to as a salt forming step);
A step of obtaining the compound (1-2) by heating the compound (0-2) in the presence of an acid having a higher acid strength than the compound (1-2) (hereinafter referred to as a carboxyl oxidation step);
The method containing is mentioned.

［式中、Ｒ^０１はアルキル基であり、Ｙ^１、Ｍ^＋は前記と同じである。］

[Wherein R ⁰¹ represents an alkyl group, and Y ¹ and M ⁺ are the same as defined above. ]

As the alkyl group for R ^01, a linear or branched alkyl group is preferable, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group. , A pentyl group, an isopentyl group, a neopentyl group, and the like. Among these, a C1-C4 alkyl group is preferable and a methyl group is the most preferable.
A commercially available compound can be used as the compound (0-1).

The salt forming step can be performed, for example, by dissolving the compound (0-1) in a solvent, adding an alkali to the solution, and heating.
Any solvent may be used as long as it dissolves the compound (0-1), and examples thereof include water and tetrahydrofuran.
As the alkali, an alkali corresponding to M in the formula (0-2) is used, and examples of the alkali include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide.
1-5 mol is preferable with respect to 1 mol of compounds (0-1), and, as for the usage-amount of an alkali, 2-4 mol is more preferable.
The heating temperature is preferably about 20 to 120 ° C, more preferably about 50 to 100 ° C. Although heating time changes with heating temperature etc., 0.5 to 12 hours are preferable normally and 1 to 5 hours are more preferable.

The neutralization after the heating can be carried out by adding an acid such as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, etc. to the reaction solution after the heating.
At this time, the neutralization is preferably performed so that the pH (25 ° C.) of the reaction solution after the acid addition is 6 to 8. Moreover, it is preferable that it is 20-30 degreeC, and, as for the temperature of the reaction liquid at the time of neutralization, it is more preferable that it is 23-27 degreeC.
After completion of the reaction, the compound (0-2) in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography and the like can be used alone or in combination of two or more.

In the carboxyl oxidation step, the compound (1-2) is obtained by heating the compound (0-2) obtained in the salt formation step in the presence of an acid having a higher acid strength than the compound (1-2). .
“Acid having higher acid strength than compound (1-2) (hereinafter sometimes simply referred to as strong acid”) has a smaller pKa (25 ° C.) value than —COOH in compound (1-2). Means acid. By using such a strong acid, -COO ^- M ⁺ in compound (0-2) becomes -COOH, and compound (1-2) is obtained.
As the strong acid, an acid having a pKa smaller than the pKa of —COOH in the compound (1-2) may be appropriately selected from known acids. The pKa of —COOH in the compound (1-2) can be determined by a known titration method.
Specific examples of strong acids include sulfonic acids such as aryl sulfonic acids and alkyl sulfonic acids, sulfuric acid, hydrochloric acid and the like. Examples of the aryl sulfonic acid include p-toluene sulfonic acid. Examples of the alkyl sulfonic acid include methane sulfonic acid and trifluoromethane sulfonic acid. As the strong acid, p-toluenesulfonic acid is particularly preferable because of its solubility in an organic solvent and ease of purification.

The carboxylation step can be carried out, for example, by dissolving compound (0-2) in a solvent, adding an acid and heating.
Any solvent may be used as long as it dissolves the compound (0-2), and examples thereof include acetonitrile and methyl ethyl ketone.
0.5-3 mol is preferable with respect to 1 mol of compounds (0-2), and, as for the usage-amount of a strong acid, 1-2 mol is more preferable.
The heating temperature is preferably about 20 to 150 ° C, more preferably about 50 to 120 ° C. Although heating time changes with heating temperature etc., 0.5 to 12 hours are preferable normally and 1 to 5 hours are more preferable.
After completion of the reaction, the compound (1-2) in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography and the like can be used alone or in combination of two or more.

In the case where W ⁺ in the compound (1-3) is the substituted ammonium ion, the compound (the compound (1-3 ″) represented by the following general formula (1-3 ″)) is, for example, the compound ( It can be produced by reacting 1-3 ′) with an ammonium salt.

［式中、Ｒ^Ｘ、Ｒ^１、Ｙ^１、Ｒ^３〜Ｒ^６はそれぞれ前記と同じである。］

[Wherein, R ^X , R ¹ , Y ¹ , R ^{3 to} R ⁶ are the same as defined above. ]

Examples of the ammonium salt used at this time include the above-mentioned alkylamines, dialkylamines, trialkylamines, and hydrochlorides or odorates of aromatic amines.
In the reaction, for example, the compound (1-3 ′) and an ammonium salt can be reacted by dissolving in a solvent such as water, dichloromethane, acetonitrile, methanol, chloroform, and stirring.
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 (1-3 ′) and ammonium salt, the reaction temperature, and the like, but usually 0.5 to 10 hours is preferable, and 1 to 5 hours is more preferable.

The method of reacting the compound (1-3) and the compound (2-1) is not particularly limited. For example, the method of bringing the compound (1-3) and the compound (2-1) into contact in a reaction solvent. Is mentioned. The method can be carried out, for example, by adding the compound (2-1) to a solution in which the compound (1-3) is dissolved in the reaction solvent in the presence of a base.
Any reaction solvent may be used as long as it can dissolve the starting compounds (1-3) and (2-1). Specifically, tetrahydrofuran (THF), acetone, dimethylformamide (DMF), dimethylacetamide , Dimethyl sulfoxide (DMSO), acetonitrile and the like.
Examples of the base include organic bases such as triethylamine, 4-dimethylaminopyridine (DMAP) and pyridine; inorganic bases such as sodium hydride, K ₂ CO ₃ and Cs ₂ CO ₃ .
About 1-3 equivalent is preferable with respect to compound (1-3), and, as for the addition amount of a compound (2-1), 1-2 equivalent is more preferable.
The reaction temperature is preferably -20 to 40 ° C, more preferably 0 to 30 ° C. Although reaction time changes also with the reactivity, reaction temperature, etc. of a compound (1-3) and a compound (2-1), 1-120 hours are preferable normally and 1-48 hours are more preferable.

When W ⁺ in the compound (b0-01) is the substituted ammonium ion, the compound (the compound (b0-01 ′) represented by the following general formula (b0-01 ′)) is, for example, the compound It can also be produced by a method in which (1-3 ′), the compound (2-1), and an amine or ammonium salt are reacted simultaneously.

［式中、Ｒ^Ｘ、Ｒ^１、Ｙ^１、Ｗ^＋、Ｘ^２２はそれぞれ前記と同じである。］

[Wherein, R ^X , R ¹ , Y ¹ , W ⁺ and X ²² are the same as defined above. ]

The compound (1-3 ′), the compound (2-1), and the amine or ammonium salt are the same as in the case of reacting the compound (1-3) and the compound (2-1). Can be reacted.
Examples of the amine used at this time include the above-described alkylamines, dialkylamines, trialkylamines, and aromatic amines. Examples of ammonium salts include tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide. (The alkyl groups in tetraalkylammonium are each independently an alkyl group having 1 to 4 carbon atoms).

In the above production method, the substituted ammonium salts such as the compound (1-3 ″) and the compound (b0-01 ′) are highly useful as intermediates in producing the compound (b1-1) of the present invention. That is, when the cation part is N ⁺ (R ³ ) (R ⁴ ) (R ⁵ ) (R ⁶ ), the compound can be easily purified by washing with water, and an improvement in the purity of the final product can be expected. When the cation part is an alkali metal ion, purification by washing with water is difficult because the compound dissolves.
Therefore, in the production method of the present invention, the compound (b1-1) is preferably produced from an intermediate having the substituted ammonium ion in the cation moiety.

The reaction of compound (b0-01) and compound (b0-02) can be carried out in the same manner as in a conventionally known salt substitution method. For example, the compound (b0-01) and the compound (b0-02) can be reacted in a solvent such as water, dichloromethane, acetonitrile, methanol, chloroform, and the like by stirring.
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 (b0-01) and the compound (b0-02), the reaction temperature, and the like, but usually 0.5 to 10 hours is preferable, and 1 to 5 hours is more preferable.

After completion of the reaction, the compound (b1-1) in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography and the like can be used alone or in combination of two or more.
The structure of the obtained compound (b1-1) is 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 and other general organic analysis methods.

≪Acid generator≫
The acid generator which is the fifth aspect of the present invention is composed of the compound (b1-1) of the present invention.
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 according to the first aspect of the present invention is a base component (A) whose solubility in an alkaline developer is changed by the action of an acid (hereinafter referred to as component (A)), and generates an acid upon exposure. And an acid generator component (B) (hereinafter referred to as component (B)).
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 components for chemically amplified resists can be used alone 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 to 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, a base component that is soluble in an alkaline developer is used as the component (A), 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 cross-linking between the base component and the cross-linking 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 coating 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. Note that 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. Especially, it is preferable that this (A) component contains (A1) component.

[(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 this embodiment, the component (A1) preferably contains a structural unit derived from an acrylate ester.
Here, in the present specification and claims, the “structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include not only acrylic acid esters in which a hydrogen atom is bonded to the α-position carbon atom, but also those in which a substituent (an atom or group other than a hydrogen atom) is bonded to the α-position carbon atom. 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.
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 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 a structural unit (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. It increases the solubility of the entire component in an alkaline developer, and those proposed so far as acid dissociable, dissolution inhibiting groups for base resins for chemically amplified resists can be used. Generally, 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, and an oxygen atom (= O).
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The “aliphatic cyclic group” 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 specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. .

  Examples of the acid dissociable, 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 may be alkyl groups (both linear and branched, preferably 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-type 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, this 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 groups excluding hydrogen atoms. Specific examples thereof 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 4-7 membered ring, and more preferably a 4-6 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またはエーテル結合を有する２価の連結基を示す。］

[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, an aliphatic cyclic group, or an ether bond 2 A valent linking group is shown. ]

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 an alkylene group, an aliphatic cyclic group, or a divalent linking group having an ether bond.
When Y ² represents an alkylene group, preferably an alkylene group having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, 1 to carbon atoms 3 is most preferred.
When Y ² is an aliphatic cyclic group, it is preferably a divalent aliphatic cyclic group, except that a group in which two or more hydrogen atoms are removed is used as the aliphatic cyclic group. The same as described for the “aliphatic cyclic group” can be used.
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. .
When Y ² is a divalent linking group having an ether bond, it is preferably a group represented by —Y ^a —O—Y ^b —.
In the group represented by —Y ^a —O—Y ^b —, Y ^a is ^a divalent hydrocarbon group having 2 or more carbon atoms which may have ^a substituent. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group is preferred. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group having a ring in the structure. Specifically, in the case where Y ² is a divalent aliphatic cyclic group or Y ² is an alkylene group, it is the same as the group having 2 or more carbon atoms. Y ^a may have a substituent, and as the substituent, when Y ^a is a chain-like aliphatic hydrocarbon group, fluorine atom, fluorine having 1 to 5 carbon atoms substituted with a fluorine atom, And when Y ^a is an aliphatic hydrocarbon group containing a ring in the structure, it is the same as the substituent in the above “aliphatic cyclic group”. is there.
Y ^a is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 2 to 5 carbon atoms, and most preferably an ethylene group.
Y ^b is a divalent hydrocarbon group having 1 or more carbon atoms which may have a substituent. Examples of the hydrocarbon group for Y ^b include divalent hydrocarbon groups having 2 or more carbon atoms similar to those described for Y ^a , and a methylene group that may have a substituent. Examples of the substituent that the methylene group may have include the same substituents as those exemplified as the substituent that the chain-like aliphatic hydrocarbon group may have.
Y ^b is preferably a linear or branched aliphatic hydrocarbon group, particularly preferably a methylene group or an alkylmethylene group.
The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

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

［式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、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またはエーテル結合を有する２価の連結基を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５の低級アルキル基を表す。］

[Wherein, 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; n represents an integer of 0 to 3] Y ² represents an alkylene group, an aliphatic cyclic group or a divalent linking group having an ether bond; R is the same as defined above, and R ¹ ′ and R ² ′ each independently represent a hydrogen atom or Represents a lower alkyl group having 1 to 5 carbon atoms. ]

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), (a1-1-17) to (a1). -1-18), (a1-1-35) to (a1-1-41), and (a1-3-49) to (a1-3-50) are used. It is more preferable.
Furthermore, as the structural unit (a1), in particular, those represented by the following general formula (a1-1-01) including the structural units of the formula (a1-1-1) to the formula (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。］

[Wherein, 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。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹² represents a lower alkyl group. 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%, and more preferably 25 to 50 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, 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 polymer compound (A1) when the polymer compound (A1) is used for forming a resist film. It is effective in enhancing 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基であり、ｍは０または１の整数であり、Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子である。］

[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 ″, and the above R ″ is A hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, m is an integer of 0 or 1, and A ″ is a carbon which may contain an oxygen atom or a sulfur atom. It is an alkylene group of formula 1 to 5, an oxygen atom or a sulfur atom.

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
Examples of the lower alkyl group for R ′ include the same as the lower alkyl group for R in the structural unit (a1).
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 Groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group 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. Is mentioned.
In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.
Specific examples of the alkylene group having 1 to 5 carbon atoms that may contain an oxygen atom or sulfur atom of A ″ include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, —O—CH ₂ —. _{, -CH 2 -O-CH 2 -} , - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
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), (a2-2-9), (a2-2-10) ), (A2-3-1), (a2-3-2), (a2-3-9) and (a2-3-10), and at least one selected from the group consisting of structural units represented by preferable.

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%, based on the total of all the structural units constituting the component (A1). 50 mol% is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting 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. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). It is done. As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, 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 defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t ′ is an integer of 1 to 3, and l is an integer of 1 to 5] And s is an integer of 1 to 3. ]

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and a hydroxyl group bonded to the 3-position of the adamantyl group is particularly preferred.
In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. 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) is sufficiently obtained, and by setting 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 not classified into the above structural units (a1) to (a3), and for ArF excimer laser, for KrF excimer laser (preferably ArF excimer) A number of hitherto known materials can be used for resist resins such as lasers.
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。］

[Wherein, R is the same 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) (polystyrene conversion standard by gel permeation chromatography) of the component (A1) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000, and 5000 to 20000. Most preferred. When it is smaller than the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist. When 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 (hereinafter sometimes referred to as the component (B1)) composed of the compound (B1) 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%. When the resist pattern is formed using the resist composition, the resolution, the mask reproducibility, the line width roughness (LWR), the pattern shape, and the exposure amount (EL) margin when the resist composition is equal to or higher than the lower limit of the range. Lithographic properties such as depth of focus (DOF) are improved.

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 but may form a ring with the sulfur atom bonded to each other; R 4 ^"represents a linear, branched or cyclic alkyl group or fluorinated alkyl group; R ¹ At least one of “˜R ³ ” represents an aryl group, and at least one of R ⁵ ”to R ⁶ ” represents an aryl group.]

Wherein ^{(b-1), R 1} "~R 3" is the same as ^R 1 ^{"~R 3"} respectively in the (b'-1).
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.

Wherein ^{(b-2), R 5} "~R 6" are the same as ^R 5 ^{"~R 6"} respectively in the (b'-1).
"The, ^{R 4} in the formula (b-1)" ^{R 4} in the In the formula (b-2) include the same as.

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. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenyl sulphonium trifluoromethane sulphonate, its heptafluoropropane sulphonate or its nonafluorobutane sulphonate; 1-phenyltetrahydrothiophenium trifluoromethane sulphonate, its heptafluoropropane sulphonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.
In addition, 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.

  In addition, in the general formula (b-1) or (b-2), an onium salt-based acid generator in which the anion moiety is replaced with an anion moiety represented by the following general formula (b-3) or (b-4). 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, 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 ″, the strength of the acid increases as the number of hydrogen atoms substituted with fluorine atoms increases, and high-energy light or electron beam of 200 nm or less 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.

In addition, an onium salt-based acid generator generates a sulfonium salt having a cation moiety represented by the general formula (b-5) or (b-6) and an anion moiety other than the anion moiety of the compound (B1). It can also be used as an agent.
As said other anion part, the anion part of the onium salt type acid generator proposed until now can be utilized, for example, the onium salt type acid represented by the said general formula (b-1) or (b-2) Fluorinated alkyl sulfonate ions such as the anion moiety (R ⁴ ″ SO ₃ ⁻ ) of the generator; anion moieties represented by the above general formula (b-3) or (b-4). , Fluorinated alkyl sulfonate ions are preferable, fluorinated alkyl sulfonate ions having 1 to 4 carbon atoms are more preferable, and linear perfluoroalkyl sulfonate ions having 1 to 4 carbon atoms are particularly preferable. Trifluoromethylsulfonic acid ion, heptafluoro-n-propylsulfonic acid ion, nonafluoro-n-butylsulfonic acid 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 (B-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

（式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

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

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

As the organic group for R ^32, a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

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

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

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

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

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

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.

As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.

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

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

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

  As the component (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>
The resist composition of the present invention preferably further contains a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) in order to improve the resist pattern shape, the stability over time and the like.
Since a wide variety of component (D) has already been proposed, any known one can 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-pentylamine, tri-n-hexylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, and the like; 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.
In addition to those listed above, stearyl diethanolamine can also be preferably used.
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 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, and 2-heptanone; many such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol Monohydric alcohols: compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate or dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or the compound having an ester bond Ether alkyl such as ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) among these]; cyclic ethers such as dioxane, methyl lactate, Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, Aromatic organics such as dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene A solvent etc. can be mentioned.
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.

The resist composition of the present invention is a novel one that has not been conventionally known.
In addition, since the compound (b1-1) of the present invention is contained as an acid generator, the lithography characteristics are also improved. For example, resolution when forming a resist pattern, mask reproducibility (for example, mask linearity) and exposure. An amount (EL) margin, a resist pattern shape, a depth of focus (DOF), and the like are improved.
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.
The reason why the above effect is obtained is estimated as follows. That is, in the compound (b1-1), the anion portion is bonded to the skeleton of “Y ¹ —SO ₃ ^— ” with R ^X —C (═O) —R ¹ —O—C (═O) —. It has a structure. Therefore, it has a higher polarity, a three-dimensionally bulky and bulky structure than the fluorinated alkyl sulfonate ions that have been conventionally used as anions. Compared to the anion part of conventional acid generators such as nonafluorobutanesulfonate, the anion part (acid) in the resist film is due to the interaction between molecules due to its high polarity and its bulky steric structure. It is assumed that diffusion is suppressed both chemically and physically. Therefore, the diffusion of the acid generated in the exposed area to the unexposed area is suppressed, and as a result, the difference in solubility (dissolution contrast) in the alkaline developer between the unexposed area and the exposed area is improved. It is estimated that the property and the resist pattern shape are improved.
The alkyl chain of good fluorinated alkylene group which may have a Y ¹ which may have a substituent alkylene group or substituent, e.g. perfluoroalkyl chains persistent C6-10 On the other hand, the degradability is good, and the handleability considering the bioaccumulation property is further improved.

≪Resist pattern formation method≫
The resist pattern forming method according to the second aspect of the present invention comprises 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 the resist film. A step of forming a resist pattern by alkali development.
The resist pattern forming method 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 prebaked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 150 ° C. under a temperature condition of 80 to 150 ° C. 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 alkali-development-processed using an alkali developing solution, for example, 0.1-10 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, Preferably, a water rinse is carried out using a pure water, and it dries. In some cases, a baking treatment (post-baking) may be performed after the alkali development treatment. 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, and particularly effective for ArF excimer laser.

The exposure of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be immersion exposure.
In immersion exposure, as described above, the portion between the lens, which has been filled with an inert gas such as air or nitrogen, and the resist film on the wafer at the time of exposure 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 this state, exposure (immersion exposure) is performed through a desired mask pattern.
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 fluorinated inert liquid include fluorinated compounds 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 main components. 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.).

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
In each of the following examples, the compound represented by the chemical formula (II) is referred to as “compound (II)”, and the compounds represented by other chemical formulas are also described in the same manner.

[Synthesis Example 1]
Compound (II) 4.34 g (purity: 94.1%), 2-benzyloxyethanol 3.14 g, toluene 43.4 g were charged, p-toluenesulfonic acid monohydrate 0.47 g was added, and 105 ° C. At reflux for 20 hours. The reaction solution was filtered, and 20 g of hexane was added to the filtrate and stirred. Filtration was performed again, and the residue was dried to obtain 1.41 g (yield: 43.1%) of compound (III).

^{1 H-NMR (DMSO-d6,400MHz} ): δ (ppm) = 4.74-4.83 (t, 1H, OH), 4.18-4.22 (t, 2H, H a), 3. 59-3.64 (q, 2H, ^Hb ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.6.
From the results described above, it was confirmed that the compound (III) had a structure shown below.

[Synthesis Example 2]
To 1.00 g of compound (III) and 3.00 g of acetonitrile, 0.82 g of 1-adamantanecarbonyl chloride and 0.397 g of triethylamine were added dropwise under ice cooling. After completion of dropping, the mixture was stirred at room temperature for 20 hours and filtered. The filtrate was concentrated to dryness, dissolved in 30 g of dichloromethane and washed with water three times. The organic layer was concentrated and dried to obtain 0.82 g (yield: 41%) of compound (IV).

The obtained compound (IV) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 8.81 (s, 1H, H ^c ), 4.37-4.44 (t, 2H, H ^d ), 4.17-4 .26 (t, 2H, H ^e ), 3.03-3.15 (q, 6H, H ^b ), 1.61-1.98 (m, 15H, Adamantane), 1.10-1.24 ( t, 9H, H ^a ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.61.
From the results described above, it was confirmed that the compound (IV) had a structure shown below.

[Example 1]
0.384 g of compound (V) was dissolved in 3.84 g of dichloromethane and 3.84 g of water, and 0.40 g of compound (IV) was added. After stirring for 1 hour, the organic layer was recovered by liquid separation treatment and washed with water 3.84 g three times. The obtained organic layer was concentrated and dried to obtain 0.44 g (yield: 81.5%) of compound (VI).

The obtained compound (VI) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.57-7.87 (m, 14H, Phenyl), 4.40-4.42 (t, 2H, H ^b ), 4. 15-4.22 (t, 2H, H ^a ), 2.43 (s, 3H, H ^c ), 1.60-1.93 (m, 15H, Adamantane).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.7.
From the results shown above, it was confirmed that the compound (VI) had a structure shown below.

[Example 2]
(I)
To 60.75 g of methanesulfonic acid controlled at 20 ° C. or less, 8.53 g of phosphorus oxide, 8.81 g of 2,5-dimethylphenol and 12.2 g of diphenyl sulfoxide were added little by little. 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. Thereafter, the reaction solution was dropped into 109.35 g of pure water cooled to 15 ° C. or lower. After completion of the dropwise addition, 54.68 g of dichloromethane was added, and after stirring, the dichloromethane layer was recovered. A separate container was charged with 386.86 g of hexane at 20 to 25 ° C., and the dichloromethane layer was added dropwise. After completion of dropping, the mixture was aged at 20 to 25 ° C. for 30 minutes, and then filtered to obtain 17.14 g (yield: 70.9%) of the objective compound (i).
The obtained compound (i) was analyzed by NMR.
¹ H-NMR (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 above results, it was confirmed that the compound (i) had a structure shown below.

(Ii)
4 g of compound (i) was dissolved in 79.8 g of dichloromethane. After confirmation of dissolution, 6.87 g of potassium carbonate was added, and 3.42 g of methyl adamantane bromoacetate was added. After reaction for 24 hours under reflux, filtration, washing with water were performed, and crystallization was performed with hexane. The obtained powder was dried under reduced pressure to obtain 3.98 g (yield 66%) of the target compound (ii).
The obtained compound (ii) was analyzed by NMR.
¹ H-NMR (CDCl ₃ , 400 MHz): δ (ppm) = 7.83-7.86 (m, 4H, Phenyl), 7.69-7.78 (m, 6H, Phenyl), 7.51 ( s, 2H, H ^d ), 4.46 (s, 2H, H ^c ), 2.39 (s, 6H, H ^a ), 2.33 (s, 2H, Adamantan), 2.17 (s, 2H) , Adamantan), 1.71-1.98 (m, 11H, Adamantan), 1.68 (s, 3H, H ^b ), 1.57-1.61 (m, 2H, Adamantan).
From the results described above, it was confirmed that the compound (ii) had a structure shown below.

(Iii)
4.77 g of compound (ii) was dissolved in 23.83 g of dichloromethane and 23.83 g of water, and 3.22 g of compound (IV) was added. After stirring for 1 hour, the organic layer was recovered by liquid separation treatment and washed with water 3.84 g three times. The obtained organic layer was concentrated and dried to obtain 4.98 g (yield 87%) of compound (X).

The obtained compound (X) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.76-7.88 (m, 10H, Phenyl), 7.62 (s, 2H, Phenyl), 4.64 (s, 2H) , H ^b ), 4.43-4.44 (t, 2H, H ^e ), 4.22-4.23 (t, 2H, H ^d ), 1.51-2.36 (m, 38H, Adamantan + H ^a + ^Hc ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.7.
From the results described above, it was confirmed that the compound (X) had a structure shown below.

[Synthesis Example 3]
2.19 g of undecanoylcarbonyl chloride and 1.01 g of triethylamine were added dropwise with cooling to 2.42 g of compound (III) and 7.26 g of acetonitrile. After completion of dropping, the mixture was stirred at room temperature for 20 hours and filtered. The filtrate was concentrated to dryness, dissolved in 20 g of dichloromethane and washed with water three times. The organic layer was concentrated and dried to obtain 3.41 g (yield: 80.4%) of compound (XI).

The obtained compound (XI) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 8.81 (s, 1H, H ^f ), 4.39-4.41 (t, 2H, H ^d ), 4.23-4 .39 (t, 2H, H ^e ), 3.06-3.10 (q, 6H, H ^h ), 2.24-2.29 (t, 2H, H ^c ), 1.09-1.51 (M, 25H, H ^b + H ^g ), 0.83-0.89 (t, 3H, H ^a ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.8.
From the results shown above, it was confirmed that the compound (XI) had a structure shown below.

[Example 3]
1.68 g of compound (XII) was dissolved in 8.41 g of dichloromethane and 8.41 g of water, and 2.00 g of compound (XI) was added. After stirring for 1 hour, the organic layer was recovered by liquid separation treatment and washed with water 3.84 g three times. The obtained organic layer was concentrated and dried to obtain 2.20 g (yield: 81.5%) of compound (XII).

The obtained compound (XII) was analyzed by NMR.
^{1 H-NMR (DMSO-d6,400MHz} ): δ (ppm) = 7.74-7.90 (m, 15H, Phenyl), 4.39-4.42 (t, 2H, H e), 4. ^{21-4.24 (t, 2H, H d} ), 2.25-2.89 (t, 3H, H c), 1.17-1.50 (m, 15H, H b), 0.79- ^{0.88 (t, 3H, H a} ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.8.
From the results shown above, it was confirmed that the compound (XII) had a structure shown below.

[Example 4, Comparative Example 1]
Each component shown in Table 1 was mixed and dissolved to prepare a positive resist composition.

Each abbreviation in Table 1 has the following meaning. Moreover, the numerical value in [] of Table 1 is a compounding quantity (mass part).
In addition, the compounding quantity of (B) component of Example 4 and Comparative Example 1 is an equimolar amount, respectively.
(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: a compound represented by the following chemical formula (B) -1 (the compound (VI)).
(B ′)-1: a compound represented by the following chemical formula (B ′)-1.
(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(S) -1: γ-butyrolactone.
(S) -2: PGMEA / PGME = 6/4 (mass ratio).

The following evaluation was performed using the obtained resist composition.
[Resist pattern formation]
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer using a spinner, and baked at 205 ° C. for 60 seconds on a hot plate and dried. Thus, an organic antireflection film having a film thickness of 82 nm was formed. Then, each of the resist compositions is applied onto the antireflection film using a spinner, prebaked (PAB) on a hot plate at 110 ° C. for 60 seconds, and dried to obtain a film thickness. A 150 nm resist film was formed.
Next, an ArF excimer laser (193 nm) is applied to the resist film by using an ArF exposure apparatus NSR-S302 (manufactured by Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination) as a mask pattern. Selectively irradiated. Then, post-exposure heating (PEB) treatment is performed at 110 ° C. for 60 seconds, and further development is performed at 23 ° C. with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 30 seconds, and then 30 Water rinsing was performed using pure water for 2 seconds, and then shaken off and dried.
As a result, in each of the examples, a line-and-space resist pattern (hereinafter referred to as an L / S pattern) having a line width of 120 nm and a pitch of 240 nm was formed on the resist film.
The optimum exposure dose Eop (mJ / cm ² ) for forming the L / S pattern having the line width of 120 nm and the pitch of 240 nm was determined.
Further, the limit resolution at the above Eop was determined as the resolution. These results are shown in Table 2.
Moreover, the cross-sectional shape of the L / S pattern having a line width of 120 nm and a pitch of 240 nm formed as described above was observed with a scanning electron microscope (trade name: S-9220, manufactured by Hitachi, Ltd.). As a result, the resist pattern shape of Example 4 was high in rectangularity compared to Comparative Example 1, such that the verticality of the line side wall was high and tailing with the substrate interface was suppressed.

[LWR evaluation]
In the L / S pattern having a line width of 120 nm and a pitch of 240 nm formed by the Eop, the line width was determined by a length measurement SEM (scanning electron microscope, acceleration voltage 800 V, trade name: S-9220, manufactured by Hitachi, Ltd.) Five points were measured in the longitudinal direction of the line, and from the result, a value (3s) that was three times the standard deviation (s) was calculated as a measure of LWR. The results are shown in Table 2. The smaller the value of 3s, the smaller the roughness of the line width, which means that a more uniform width L / S pattern was obtained.

[EL margin evaluation]
An L / S pattern having a line width of 120 nm and a pitch of 240 nm as target dimensions was formed in the same procedure as above except that the exposure amount was changed.
At this time, the exposure amount when the line of the L / S pattern was formed with ± 5% (114 nm, 126 nm) of the target dimension (line width 120 nm) was obtained, and the EL margin (unit:%) was obtained by the following equation. . The results are shown in Table 2.
EL margin (%) = (| E1-E2 | / Eop) × 100
[Where E1 represents an exposure amount (mJ / cm ² ) when an L / S pattern having a line width of 114 nm is formed, and E2 is an exposure when an L / S pattern having a line width of 126 nm is formed. The amount (mJ / cm ² ) is shown. ]

[Mask error factor (MEF) evaluation]
In the above Eop, an L / S pattern is formed using a mask pattern that targets an L / S pattern with a line width of 130 nm and a pitch of 260 nm and a mask pattern that targets an L / S pattern with a line width of 120 nm and a pitch of 260 nm. And the value of MEF was calculated | required from the following formula | equation.
MEF = | CD ₁₃₀ −CD ₁₂₀ | / | MD ₁₃₀ −MD ₁₂₀ |
In the above formula, CD ₁₃₀ and CD ₁₂₀ are the actual line widths (nm) of the L / S pattern formed using the mask pattern targeting the line widths 130 nm and 120 nm, respectively. MD ₁₃₀ and MD ₁₂₀ are line widths (nm) targeted by the mask pattern, respectively, and MD ₁₃₀ = 130 and MD ₁₂₀ = 120. The closer this MEF value is to 1, the more the resist pattern faithful to the mask pattern is formed.
As a result, Example 4 was 2.0 and Comparative Example 1 was 2.0, which were equivalent.

[Mask linearity evaluation]
In the above Eop, the L / S ratio of the mask pattern (ratio of line width to space width) is fixed to 1: 1, and the mask size (line width) is changed by 10 nm in the range of 110 to 150 nm, respectively. An S pattern was formed, and the size (line width) of the formed L / S pattern was measured. The results are shown in Table 3.
As shown in Table 3, in Example 4, an L / S pattern having a size more faithful to the mask size than Comparative Example 1 was formed at 120 nm Eop even when the size was far from 120 nm. It was confirmed that the resist composition of Example 4 was superior in mask reproducibility to the resist composition of Comparative Example 1.

  From the above results, it was confirmed that the resist composition of Example 4 was excellent in lithography characteristics.

[Examples 5 to 7, Comparative Example 2]
Each component shown in Table 4 was mixed and dissolved to prepare a positive resist composition.

In Table 4, (A) -1, (D) -1, (S) -1, (S) -2 are (A) -1, (D) -1, (S) -1, It means the same as (S) -2, and the other abbreviations have the following meanings. Moreover, the numerical value in [] is a compounding quantity (mass part).
In addition, the compounding quantity (total amount) of (B) component of Examples 5-7 and Comparative Example 2 is an equimolar amount, respectively.
(B) -2: a compound represented by the following chemical formula (B) -2 (the compound (X)).
(B ′)-2: A compound represented by the following chemical formula (B ′)-2.

The following evaluation was performed using the obtained resist composition.
[Resist pattern formation]
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer using a spinner, and baked at 205 ° C. for 60 seconds on a hot plate and dried. Thereby, an organic antireflection film having a film thickness of 89 nm was formed. Then, each of the resist compositions is applied onto the antireflection film using a spinner, prebaked (PAB) on a hot plate at 110 ° C. for 60 seconds, and dried to obtain a film thickness. A 150 nm resist film was formed.
Next, a protective film-forming coating solution “TILC-035” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied onto the resist film using a spinner, and heated at 90 ° C. for 60 seconds. A top coat having a thickness of 90 nm was formed.
Next, an ArF immersion exposure apparatus NSR-S609B (manufactured by Nikon Corporation; NA (numerical aperture) = 1.07, σ0.97) is used to form the resist film on which the top coat has been formed through a hole pattern mask. On the other hand, ArF excimer laser (193 nm) was selectively irradiated.
As a result, in any of the examples, a contact hole pattern (hereinafter referred to as a dense CH pattern) in which holes with a hole diameter of 90 nm were arranged at equal intervals (pitch 180 nm) could be formed in the resist film.
Next, a contact hole pattern (hereinafter referred to as an Iso CH pattern) in which holes having a hole diameter of 90 nm are arranged at equal intervals (pitch 570 nm) at an optimum exposure dose Eop (mJ / cm ² ) at which the dense CH pattern is formed. .) Was formed.
Lithography characteristics in the 90 nm diameter Iso CH pattern were evaluated. The results are shown in Table 5.

[Depth of focus (DOF) evaluation]
At Eop, the focus is appropriately shifted up and down to form a resist pattern in the same manner as in [Resist pattern formation], and the Iso CH pattern has a target dimension of ± 5% (ie, 85.5 to 94.5 nm). The depth of focus (DOF, unit: nm) that can be formed within the range of the change rate was determined. The results are shown in Table 5.

[MEF evaluation]
A CH pattern having a pitch of 570 nm was formed using the mask patterns with the hole diameter target sizes of 61 nm, 63 nm, 65 nm, 67 nm, and 69 nm, respectively, at the above Eop. At this time, the slope of the straight line when the target size (nm) was plotted on the horizontal axis and the aperture (nm) of the hole 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 results obtained are shown in Table 5.

[EL margin evaluation]
The exposure amount when an iso-CH pattern having a diameter of 90 nm is formed with ± 5% (85.5 nm, 94.5 nm) of the target dimension (hole diameter 90 nm) is obtained, and the EL margin (unit:%) is obtained by the following formula. It was. The results are shown in Table 5.
EL margin (%) = (| E1-E2 | / Eop) × 100
[In the formula, E1 represents an exposure amount (mJ / cm ² ) when a CH pattern having a hole diameter of 85.5 nm is formed, and E2 is an exposure when a CH pattern having a hole diameter of 94.5 nm is formed. The amount (mJ / cm ² ) is shown. ]

  As shown in Table 5, the resist compositions of Examples 5 to 7 had better MEF and EL margin than the resist composition of Comparative Example 2, and the DOF was equivalent or better.

  From the above results, it was confirmed that the compound of the present invention was useful as an intermediate of a compound useful as an acid generator.

[Examples 8 to 14]
Each component shown in Table 6 was mixed and dissolved to prepare a positive resist composition.

In Table 6, (B) -1, (D) -1, and (S) -2 mean the same as (B) -1, (D) -1, and (S) -2 in Table 1, Other abbreviations have the following meanings. Moreover, the numerical value in [] is a compounding quantity (mass part).
In addition, the compounding quantity (total quantity) of (B) component of Examples 8-14 is an equimolar quantity, respectively.
(A) -2: Mw = 10000 and Mw / Mn = 2.0 represented by the following chemical formula (A) -2 (where 1 / m / n = 30/50/20 (molar ratio)) Polymer.
(A) -3: Mw = 10000 and Mw / Mn = 2.0 represented by the following chemical formula (A) -3 (where 1 / m / n = 40/40/20 (molar ratio)) Polymer.

The following evaluation was performed using the obtained resist composition.
[Resist pattern formation]
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto a 12-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to be dried. As a result, an organic antireflection film having a thickness of 70 nm was formed. Then, each of the resist compositions is applied onto the antireflection film using a spinner, prebaked (PAB) on a hot plate at 110 ° C. for 60 seconds, and dried to obtain a film thickness. A 170 nm resist film was formed.
Next, an ArF excimer laser (193 nm) is applied to the resist film using an ArF exposure apparatus NSR-S308F (Nikon Corp .; NA (numerical aperture) = 0.85, σ = 0.95) and a mask pattern. Selectively irradiated. Then, post-exposure heating (PEB) treatment is performed at 90 ° C. for 60 seconds, and further development is performed at 23 ° C. with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 30 seconds, and then 30 Water rinsing was performed using pure water for 2 seconds, and then shaken off and dried.
As a result, in any of the examples, a dense CH pattern in which holes having a hole diameter of 110 nm were arranged at equal intervals (pitch 210 nm) could be formed on the resist film.
Next, an Iso CH pattern in which holes having a hole diameter of 110 nm are arranged at equal intervals (pitch 780 nm) was formed at an optimum exposure dose Eop (mJ / cm ² ) at which the Dense CH pattern was formed.
Lithography characteristics in each CH pattern of Dense / Iso having a diameter of 110 nm were evaluated. The results are shown in Table 7.

[Depth of focus (DOF) evaluation]
At Eop, the focus is appropriately shifted up and down to form a resist pattern in the same manner as in [Registration pattern formation], and each CH pattern has a target dimension of ± 5% (that is, 104.5 to 115.5 nm). The depth of focus (DOF, unit: nm) that can be formed within the range of the change rate was determined.

[MEF evaluation]
Each CH pattern was formed by the above Eop using a mask pattern in which the target size of the hole diameter was changed by 1 nm in a range of 110 nm ± 5 nm (pitch is Dense: 210 nm, Iso: 780 nm). At this time, the slope of the straight line when the mask size (nm) was plotted on the horizontal axis and the aperture (nm) of the hole pattern formed in 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.

[Evaluation of CDU (Hole Diameter Uniformity)]
About each obtained CH pattern, the diameter of the hole was measured, respectively (Dense: 54 pieces, Iso: 26 pieces), and the triple value (3σ) of the standard deviation (σ) calculated from the result was obtained. 3σ obtained in this way means that the smaller the value, the higher the CDU of each hole formed in the resist film, that is, the smaller the variation in the diameter of the holes existing within a certain range.

[Roundness evaluation]
The hole shape in each CH pattern was observed with a length measurement SEM (manufactured by Hitachi, Ltd., product name: S-9220) and evaluated according to the following criteria.
A: The roundness is very high (no irregularities were seen on the circumference of the hole pattern observed from above, and the shape was very good).
○: High roundness (although some irregularities are seen on the circumference of the hole pattern observed from above, the overall shape was highly round).

As shown in Table 7, the resist compositions of Examples 8 to 14 had excellent lithography properties (DOF, MEF, CDU, roundness) in both the dense / iso-CH pattern. Regarding the hole shapes such as CDU and roundness, it was found that the resist compositions of Examples 9 to 13 were particularly good.
From the above results, it was confirmed that the compound of the present invention was useful as an intermediate of a compound suitable as an acid generator.

[Synthesis Example 4]
To 8.00 g of compound (III) and 150.00 g of dichloromethane, 7.02 g of 1-adamantaneacetyl chloride and 3.18 g of triethylamine were added dropwise under ice cooling. After completion of dropping, the mixture was stirred at room temperature for 20 hours and filtered. The filtrate was washed 3 times with 54.6 g of pure water, and the organic layer was concentrated and dried to obtain 14.90 g (yield: 88.0%) of compound (VII).

The obtained compound (VII) was analyzed by NMR.
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 8.81 (br s, 1 H, H ^c ), 4.40 (t, 2 H, H ^d ), 4.20 (t, 2 H, H ^e) ), 3.08 (q, 6H, H ^b ), 2.05 (s, 2H, H ^f ), 1.53-1.95 (m, 15H, Adamantane), 1.17 (t, 9H, H) ^a )
¹⁹ F-NMR (DMSO, 376 MHz): δ (ppm) = − 106.90.
From the results shown above, it was confirmed that the compound (VII) had a structure shown below.

[Example 15]
7.04 g of compound (V) was dissolved in 70.4 g of dichloromethane and 70.4 g of water, and 9.27 g of compound (VII) was added. After stirring for 1 hour, the organic layer was collected by liquid separation treatment, and washed once with 70.4 g of 1% HClaq and 4 times with 70.4 g of pure water. The obtained organic layer was concentrated and dried to obtain 11.59 g (yield 90.6%) of compound (VIII).

The obtained compound (VIII) was analyzed by NMR.
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 7.50-7.87 (m, 14H, Phenyl), 4.42 (s, 2H, H ^c ), 4.23 (s, 2H , H ^b ), 2.43 (s, 3H, H ^a ), 2.01 (s, 2H, H ^f ), 1.94 (s, 2H, Adamantane), 1.52-1.61 (m, 13H, Adamantane)
¹⁹ F-NMR (DMSO, 376 MHz): δ (ppm) = − 106.49
From the results shown above, it was confirmed that the compound (VIII) had a structure shown below.

[Example 16]
21.6 g of compound (XX), 53.0 g of water, and 69.7 g of dichloromethane were stirred at room temperature, and 12.9 g of compound (IV) was added thereto. After stirring for 1 hour, the organic layer was recovered by liquid separation treatment, and washed once with 14.9% HClaq 34.9 g and twice with 69.7 g of pure water. The obtained organic layer was concentrated and dried to obtain 9.94 g (yield 61.4%) of compound (XXI).

The obtained compound (XXI) was analyzed by NMR.
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 8.00 (d, 2H, H ^f ), 7.75 (t, 1H, H ⁱ ), 7.58 (t, 2H, H ^g ) 5.30 (s, 2H, H ^e ), 4.37-4.44 (t, 2H, H ^a ), 4.17-4.26 (t, 2H, H ^b ), 3.54 (m , 4H, H ^d ), 2.49-1.18 (m, 4H, H ^c ), 1.93-1.60 (m, 15H, -Adamantane),
¹⁹ F-NMR (DMSO, 376 MHz): δ (ppm) = − 106.2
From the results shown above, it was confirmed that the compound (XXI) had a structure shown below.

[Examples 17 to 19]
Each component shown in Table 8 was mixed and dissolved to prepare a positive resist composition.

In Table 8, (B) -1 and (S) -2 mean the same as (B) -1 and (S) -2 in Table 1, and the other abbreviations have the following meanings. Moreover, the numerical value in [] is a compounding quantity (mass part).
In addition, the compounding quantity (total quantity) of (B) component of Examples 17-19 is an equimolar quantity, respectively.
(A) -4: Mw = 10,000, Mw / Mn = 2.0 represented by the following chemical formula (A) -4 (wherein l / m / n = 30/50/20 (molar ratio)) Copolymer.
(A) -5: Mw = 10,000, Mw / Mn = 2.0 represented by the following chemical formula (A) -5 (wherein 1 / m / n = 30/50/20 (molar ratio)) Copolymer.
(A) -6: Polymer compound (A) -6 (synthesized in Reference Example 3 described later)
(B) -3: A compound represented by the following chemical formula (B) -3 (the compound (VIII)).
(B) -4: A compound represented by the following chemical formula (B) -4 (the compound (XXI)).
(D) -2: Stearyl diethanolamine.

[Synthesis Example of Polymer Compound (A) -6]
[Reference Example 1]
Into a 1 L three-necked flask, 4.8 g of sodium hydride (NaH) was added, while maintaining at 0 ° C. in an ice bath, 300 g of tetrahydrofuran (THF) was added, and 124 g of compound (1) was further added with stirring. Stir for 10 minutes. Thereafter, 30 g of the compound (2) was added with stirring and reacted for 12 hours. After completion of the reaction, the reaction solution was subjected to suction filtration, and THF was removed from the collected filtrate by concentration under reduced pressure. Thereafter, water and ethyl acetate were added to the concentrate for extraction, and the resulting ethyl acetate solution was concentrated under reduced pressure and purified by column chromatography (SiO ₂ , heptane: ethyl acetate = 8: 2), and the fractions were reduced in pressure. Concentration and further drying under reduced pressure gave 12 g of compound (3).

About the obtained compound (3), < ¹ > H-NMR was measured. The results are shown below.
¹ H-NMR (solvent: CDCl ₃ , 400 MHz): δ (ppm) = 4.09 (s, 2H (H ^a )), 3.75 (t, 2H (H ^b )), 3.68 (t, ^{2H (H c)), 3.03} (brs, 2H (H d)), 1.51-2.35 (m, 17H (H e)).
From the results described above, it was confirmed that the compound (3) had a structure shown below.

[Reference Example 2]
To a 300 mL three-necked flask, 5 g of compound (3), 3.04 g of triethylamine (Et ₃ N) and 10 g of THF were added and stirred for 10 minutes. Thereafter, 2.09 g of the compound (4) and 10 g of THF were added and reacted at room temperature for 12 hours. After completion of the reaction, the reaction solution was subjected to suction filtration, and THF was removed from the collected filtrate by concentration under reduced pressure. Thereafter, water and ethyl acetate were added to the concentrated solution for extraction. The obtained ethyl acetate solution was purified by column chromatography (SiO ₂ , heptane: ethyl acetate = 8: 2), the fraction was concentrated under reduced pressure, and further dried under reduced pressure to obtain 4.9 g of compound (5). .

About the obtained compound (5), < ¹ > H-NMR was measured. The results are shown below.
¹ H-NMR (solvent: CDCl ₃ , 400 MHz): δ (ppm) = 6.15 (s, 1H (H ^a )), 5.58 (s, 1 H (H ^b )), 4.35 (t, ^{2H (H c)), 4.08} (s, 2H (H d)), 3.80 (t, 2H (H e)), 1.51-2.35 (m, 20H (H f)).
From the results shown above, it was confirmed that the compound (5) had a structure shown below.

[Reference Example 3 (Synthesis of polymer compound (A) -6)]
6.30 g (30.30 mmol) of compound (6), 7.00 g (20.83 mmol) of compound (5), 2.83 g (11.99 mmol) of compound (7) are dissolved in 64.52 g of methyl ethyl ketone. I let you. To this solution, 11.68 mmol of Wako Pure Chemical V-601 (polymerization initiator) was added and dissolved. The resultant was dropwise added to 26.88 g of methyl ethyl ketone heated to 75 ° C. in a nitrogen atmosphere over 6 hours. After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature.
The polymerization liquid was concentrated to a solid content of 30% by mass and dropped into 320 mL of n-heptane at room temperature to precipitate a copolymer. Subsequently, 54 g of this copolymer in THF was prepared and added dropwise to 320 mL of n-heptane to precipitate the copolymer.
The copolymer was dispersed in a mixed solution of methanol / water = 60/40 (volume ratio) to wash the copolymer, and subsequently methanol / water = 70/30 (volume ratio). After the operation of washing the copolymer by dispersing in a mixed solution, it was recovered by filtration.
The copolymer thus obtained was dried at 40 ° C. for 3 days to obtain 12.0 g of white powder (yield 74%).
The obtained copolymer is referred to as polymer compound (A) -6, and the structural formula thereof is shown below. As a result of measuring ¹³ C-NMR (600 MHz) for the polymer compound (A) -6, the polymer composition (ratio (molar ratio) of each structural unit in the following structural formula) was 1 / m / n = 52. 6 / 27.5 / 19.9. Moreover, the standard polystyrene conversion mass mean molecular weight (Mw) calculated | required by GPC measurement was 5,300, and dispersion degree (Mw / Mn) was 1.97. From this result, it was confirmed that the obtained polymer compound (A) -6 was a copolymer of the compound (6), the compound (5) and the compound (7).

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

[Resist pattern formation]
An organic antireflection film composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto a 12-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a film thickness of 89 nm was formed. Then, the positive resist compositions of Examples 17 to 19 obtained above were applied on the antireflection film using a spinner, and prebaked (PAB) on the hot plate at 90 ° C. for 60 seconds. ) A resist film having a film thickness of 120 nm was formed by performing treatment and drying.
Next, a protective film-forming coating solution “TSRC-002” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied onto the resist film using a spinner and heated at 90 ° C. for 60 seconds. A top coat having a thickness of 28 nm was formed.
Next, an immersion ArF exposure apparatus NSR-S609B (Nikon Corporation; NA (numerical aperture) = 1.07, 2/3 annular illumination, reduction magnification 1/4) is applied to the resist film on which the top coat is formed. The ArF excimer laser (193 nm) was selectively irradiated through the mask pattern (6% halftone) with a double immersion medium: water.
Next, the top coat was removed using a protective film removing solution “TS-Remover-S” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.), and then subjected to PEB treatment under the conditions described in Table 8, followed by 23 ° C. Developed with 2.38 mass% TMAH aqueous solution NMD-W (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 30 seconds, rinsed with pure water for 25 seconds, and then shaken and dried. went.
As a result, a CH pattern having a diameter of 70 nm and a pitch of 131 nm was formed in any of the examples. Table 9 shows the optimum exposure amount Eop (mJ / cm ² ), that is, sensitivity at this time.

[Roundness evaluation]
The hole shape in each CH pattern was observed with a length measuring SEM (manufactured by Hitachi, Ltd., product name: S-9220) and evaluated according to the same criteria as in Examples 8-14. The results are shown in Table 9.

  From the results in Table 9, it was confirmed that the compound of the present invention was useful as an intermediate of a compound suitable as an acid generator.

Claims (10)

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 exposure,
The resist composition, wherein the acid generator component (B) includes an acid generator (B1) composed of a compound represented by the following general formula (b1-1).

[Wherein, R ^X is an aliphatic group which may have a substituent (excluding a nitrogen atom); R ¹ is an alkylene group; Y ¹ is an alkylene group having 1 to 4 carbon atoms] Or it is a fluorinated alkylene group; Z ^<+> is an organic cation (however, the ion represented by the following general formula (w-1) is remove | excluded). ]

[Wherein, R ^{3 to} R ⁶ are each independently a hydrogen atom or an optionally substituted hydrocarbon group, and at least one of R ^{3 to} R ⁶ is the hydrocarbon group. , R ^{3 to} R ⁶ may be bonded to each other to form a ring. ]   The resist composition according to claim 1, 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 2, comprising a structural unit (a1) derived from   The resist composition according to claim 3, 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 3 or 4, wherein the resin component (A1) further has a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.   The resist composition as described in any one of Claims 1-5 containing a nitrogen-containing organic compound (D).   A step of forming a resist film on the support using the resist composition according to any one of claims 1 to 6, a step of exposing the resist film, and an alkali developing of the resist film to form a resist pattern A resist pattern forming method including a step of forming a film. The compound represented by the following general formula (b1-1).

[Wherein, R ^X is an aliphatic group which may have a substituent (excluding a nitrogen atom); R ¹ is an alkylene group; Y ¹ is an alkylene group having 1 to 4 carbon atoms] Or it is a fluorinated alkylene group; Z ^<+> is an organic cation (however, the ion represented by the following general formula (w-1) is remove | excluded). ]

[Wherein, R ^{3 to} R ⁶ are each independently a hydrogen atom or an optionally substituted hydrocarbon group, and at least one of R ^{3 to} R ⁶ is the hydrocarbon group. , R ^{3 to} R ⁶ may be bonded to each other to form a ring. ] By reacting the compound (b0-01) represented by the following general formula (b0-01) with the compound (b0-02) represented by the following general formula (b0-02), the following general formula (b1- The manufacturing method of the compound including the process of obtaining the compound (b1-1) represented by 1).

[Wherein, R ^X is an aliphatic group which may have a substituent (excluding a nitrogen atom); R ¹ is an alkylene group; Y ¹ is an alkylene group having 1 to 4 carbon atoms] Or a fluorinated alkylene group; W ⁺ is an alkali metal ion or an ion represented by the following general formula (w-1); Z ⁺ is an organic cation (however, represented by the following general formula (w-1)) And A ⁻ is a non-nucleophilic anion. ]

[Wherein, R ^{3 to} R ⁶ are each independently a hydrogen atom or an optionally substituted hydrocarbon group, and at least one of R ^{3 to} R ⁶ is the hydrocarbon group. , R ^{3 to} R ⁶ may be bonded to each other to form a ring. ]   An acid generator comprising the compound according to claim 8.