JP2010111660A - Resist composition, resist pattern-forming method, compound, and acid generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new compound suitable as an acid generator for a resist composition, to provide an acid generator comprising the compound, to provide a resist composition containing the acid generator, and to provide a resist pattern-forming method using the resist composition. <P>SOLUTION: The compound is represented by general formula (b1-14). The acid generator comprising such a compound is provided. The resist composition includes (A) a base material component variable in its solubility to an alkaline developer by the action of an acid and (B) an acid generator component generating an acid on being exposed; wherein the acid generator component (B) includes an acid generator (B1) comprising such compound. In the general formula, R<SP>7</SP>" to R<SP>9</SP>" are each independently aryl or alkyl, wherein any two of them are bound to each other to optionally form a ring together with the sulfur atom, and at least one of R<SP>7</SP>" to R<SP>9</SP>" is a substituted aryl group where part or the whole of the hydrogen atoms substituted with alkoxycarbonyl alkyloxy group(s); and X<SP>-</SP>is an anion. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film. A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but now mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. In addition, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.

  Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist containing a base resin whose solubility in an alkaline developer is changed by the action of an acid and an acid generator that generates an acid upon exposure is used. For example, a positive chemically amplified resist contains, as a base resin, a resin whose solubility in an alkaline developer is increased by the action of an acid and an acid generator, and from the acid generator by exposure during resist pattern formation. When the acid is generated, the exposed portion becomes alkali-soluble.

Up to now, as the base resin for chemically amplified resist, polyhydroxystyrene (PHS), which is highly transparent to KrF excimer laser (248 nm), and a resin whose hydroxyl group is protected with an acid dissociable, dissolution inhibiting group (PHS resin) Has been used. However, since the PHS resin has an aromatic ring such as a benzene ring, the transparency to light having a wavelength shorter than 248 nm, for example, 193 nm, is not sufficient. Therefore, a chemically amplified resist having a PHS-based resin as a base resin component has drawbacks such as low resolution in a process using 193 nm light, for example.
Therefore, as a resist base resin currently used in ArF excimer laser lithography and the like, it has a structural unit generally derived from a (meth) acrylic acid ester in its main chain because of its excellent transparency near 193 nm. Resin (acrylic resin) is used. In the case of the positive type, the resin includes a structural unit derived from a (meth) acrylic acid ester containing a tertiary alkyl ester type acid dissociable, dissolution inhibiting group containing an aliphatic polycyclic group, for example, 2-alkyl. A resin having a structural unit derived from 2-adamantyl (meth) acrylate or the like is mainly used (for example, see Patent Document 1).

  The “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position. “(Meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position.

  On the other hand, various acid generators used in chemically amplified resists have been proposed so far, such as onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, Diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators and the like are known. Currently, an acid generator containing a triphenylsulfonium skeleton, a dinaphthyl monophenylsulfonium skeleton, or the like is used as an acid generator (Patent Document 2).

JP 2003-241385 A Japanese Patent Laid-Open No. 2005-37888

In recent years, the miniaturization of resist patterns has further progressed, and as the demand for high resolution has further increased, various improvements in lithography properties have been demanded.
For example, it is important to suppress variations in pattern size (PEB Sensitivity: hereinafter referred to as “PEBs”) accompanying changes in temperature (PEB temperature) during PEB when forming a resist pattern. When PEBs are deteriorated, a desired resist pattern size cannot be stably formed when a resist pattern is formed, and it becomes difficult to reproduce a pattern with a fine dimension.
Improvement of the pattern shape and mask reproducibility when a resist pattern is formed becomes more important as the pattern becomes finer. For example, the mask error factor (MEF) and LWR are one of the indexes indicating such characteristics, and their improvement is important. The mask error factor is a mask pattern with different size when the mask size (line width in a line and space pattern or hole diameter in a contact hole pattern) is changed with the same exposure amount and a fixed pitch. This is a parameter indicating how faithfully it can be reproduced (mask reproducibility). LWR is a phenomenon in which the line width of the formed line pattern becomes non-uniform, and the improvement becomes more important as the pattern becomes finer. Improvement of such resist pattern shape and PEBs is important for the improvement of lithography properties, and it is considered that this purpose can be achieved by using a novel acid generator.
The present invention has been made in view of the above circumstances, and is a novel compound suitable as an acid generator for a resist composition, an acid generator comprising the compound, a resist composition containing the acid generator, and the It is an object of the present invention to provide a resist pattern forming method using a resist composition.

A first aspect of the present invention that solves the above-described problems includes a base material component (A) whose solubility in an alkali developer is changed by the action of an acid and an acid generator component (B) that generates an acid upon exposure. A resist composition comprising:
The acid generator component (B) is a resist composition containing an acid generator (B1) composed of a compound represented by the following general formula (b1-14).

［式中、Ｒ^７”〜Ｒ^９”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^７”〜Ｒ^９”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^７”〜Ｒ^９”のうち少なくとも１つは、水素原子の一部が下記一般式（ｂ１４−２）で表される基で置換された置換アリール基であり；Ｘ⁻はアニオンである。］

[Wherein, R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group; any two of R ⁷ ″ to R ⁹ ″ are bonded to each other to form a sulfur atom in the formula A ring may be formed; at least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group in which a part of hydrogen atoms is substituted with a group represented by the following general formula (b14-2) ; X ^- is an anion. ]

［式中、Ｒ^５０は直鎖状もしくは分岐鎖状のアルキレン基であり、Ｒ^５１は炭素数１〜６のアルキル基であり、Ｒ^５２は水素原子または炭素数１〜５のアルキル基であり、ｎは０または１〜６の整数である。上記単環構造を構成する−ＣＨ_２−は、酸素原子（−Ｏ−）で置換されていても良い。］

[Wherein, R ⁵⁰ is a linear or branched alkylene group, R ⁵¹ is an alkyl group having 1 to 6 carbon atoms, and R ⁵² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. , N is 0 or an integer of 1-6. —CH ₂ — constituting the monocyclic structure may be substituted with an oxygen atom (—O—). ]

  The second aspect of the present invention includes 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.

  Furthermore, the third aspect of the present invention is a compound represented by the following general formula (b1-14).

［式中、Ｒ^７”〜Ｒ^９”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^７”〜Ｒ^９”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^７”〜Ｒ^９”のうち少なくとも１つは、水素原子の一部が下記一般式（ｂ１４−２）で表される基で置換された置換アリール基であり；Ｘ⁻はアニオンである。］

[Wherein, R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group; any two of R ⁷ ″ to R ⁹ ″ are bonded to each other to form a sulfur atom in the formula A ring may be formed; at least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group in which a part of hydrogen atoms is substituted with a group represented by the following general formula (b14-2) ; X ^- is an anion. ]

［式中、Ｒ^５０は直鎖状もしくは分岐鎖状のアルキレン基であり、Ｒ^５１は炭素数１〜６のアルキル基であり、Ｒ^５２は水素原子または炭素数１〜５のアルキル基であり、ｎは０または１〜６の整数である。上記単環構造を構成する−ＣＨ_２−は、酸素原子（−Ｏ−）で置換されていても良い。］

[Wherein, R ⁵⁰ is a linear or branched alkylene group, R ⁵¹ is an alkyl group having 1 to 6 carbon atoms, and R ⁵² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. , N is 0 or an integer of 1-6. —CH ₂ — constituting the monocyclic structure may be substituted with an oxygen atom (—O—). ]

  Furthermore, the fourth aspect of the present invention is an acid generator comprising the compound of the third aspect.

In the present specification and claims, “structural unit” means a monomer unit (monomer unit) constituting a resin component (polymer, copolymer, resin).
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.
The “lower alkyl group” means an alkyl group having 1 to 5 carbon atoms.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
An “acid-dissociable group” is an organic group that can be dissociated by the action of an acid.
“Exposure” is a concept that includes radiation exposure in general.

  The present invention provides a resist composition, a method for forming a resist pattern using the resist composition, a novel compound suitable as an acid generator for the resist composition, and an acid generator comprising the compound.

Hereinafter, the present invention will be described in more detail.
<< Compound of the third aspect >>
First, the compound according to the third aspect of the present invention will be described. The compound of the third aspect of the present invention is represented by the general formula (b1-14).
In the general formula (b1-14), R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group. However, at least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group in which a part of hydrogen atoms is substituted with an alkoxycarbonylalkyloxy group.
The aryl group for R ⁷ ″ to R ⁹ ″ is not particularly limited and is, for example, an aryl group having 6 to 20 carbon atoms, and the aryl group is a substituent other than an alkoxycarbonylalkyloxy group, for example, an alkyl group. It may or may not be substituted with a group, an alkoxy group, a halogen atom, a hydroxyl group or the like. Such an aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Is most preferred.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, Most preferred is a tert-butoxy group.
The halogen atom that may substitute the hydrogen atom of the aryl group is preferably a fluorine atom.
There is no restriction | limiting in particular as an alkyl group of R < ⁷ >"-R< ⁹ >", For example, a C1-C10 linear, branched or cyclic alkyl group etc. are mentioned. 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.

At least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group in which a part of hydrogen atoms is substituted with an alkoxycarbonylalkyloxy group. R 7 ^{"~R 9"} 2 or more of the may be the substituted aryl group, but is most preferably any one of R 7 ^{"~R 9"} is the substituted aryl group.

  As said alkoxycarbonylalkyloxy group, what is represented by the following general formula (b14-2) is mentioned, for example.

［式中、Ｒ^５０は直鎖状もしくは分岐鎖状のアルキレン基であり、Ｒ^５１は炭素数１〜６のアルキル基であり、Ｒ^５２は水素原子または炭素数１〜５のアルキル基であり、ｎは０または１〜６の整数である。上記単環構造を構成する−ＣＨ_２−は、酸素原子（−Ｏ−）で置換されていても良い。］

[Wherein, R ⁵⁰ is a linear or branched alkylene group, R ⁵¹ is an alkyl group having 1 to 6 carbon atoms, and R ⁵² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. , N is 0 or an integer of 1-6. —CH ₂ — constituting the monocyclic structure may be substituted with an oxygen atom (—O—). ]

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.
The alkyl group having 1 to 6 carbon atoms in R ⁵¹ is a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a tert-butyl group, a cyclopentyl group, or a cyclohexyl group, It is preferably 1 to 4, and more preferably 1 to 3 carbon atoms.
n is 0 or an integer of 1 to 6, preferably 0 or 1 to 4, and more preferably 1 to 2.
R ⁵² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and is the same as described for the alkyl group in which the hydrogen atom of the aryl group of R ⁷ ″ to R ⁹ ″ may be substituted. A hydrogen atom or a methyl group is preferable.

  Specific examples of the group represented by the general formula (b14-2) include 1-methyl-1-cyclopentyloxycarbonylmethyloxy group, 1-ethyl-1-cyclopentyloxycarbonylmethyloxy group, 1-isopropyl-1 -Cyclopentyloxycarbonylmethyloxy group, 1-methyl-1-cyclohexyloxycarbonylmethyloxy group, 1-ethyl-1-cyclohexyloxycarbonylmethyloxy group, 1-isopropyl-1-cyclohexyloxycarbonylmethyloxy group, 1-methyl -1-cyclooctyloxycarbonylmethyloxy group, 1-ethyl-1-cyclooctyloxycarbonylmethyloxy group, 1-isopropyl-1-cyclooctyloxycarbonylmethyloxy group, 4-methyltetrahydropyranyloxy Rubo methylpropenylmethyl group, 4-ethyl-tetrahydropyranyloxy carbonyl methyl group, 3-methyl-tetrahydrofuranyl butyloxycarbonylmethyl group, such as 3-ethyl-tetrahydrofuranyl oxycarbonyl methyloxy group.

  The number of alkoxycarbonylalkyloxy groups in the substituted aryl group is preferably 1 to 3, more preferably 1 to 2, and most preferably 1. By setting it as the said range, PEBs improves. Further, the resist pattern shape such as MEF or LWR is improved.

R ⁷ ″ to R ⁹ ″ other than the substituted aryl group are each preferably a phenyl group or a naphthyl group, and most preferably a phenyl group.

Any two of R ⁷ ″ to R ⁹ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula. In this case, it is preferable to form a 3- to 10-membered ring including a sulfur atom, and it is particularly preferable to form a 5- to 7-membered ring. In particular, benzothiophene, dibenzothiophene, tetrahydrothiophene, tetrahydrothiopyran and the like can be mentioned.

In the general formula (b1-14), X ⁻ represents an anion. The anion portion of X ⁻ is not particularly limited, and those known as the anion portion of the onium salt acid generator can be appropriately used. In formula (b1-14), the anion of X ⁻ is not particularly limited, and examples thereof include sulfonate anions, imide anions, and methide anions.
Examples of preferable anions as the sulfonate anion include anions represented by the following general formula (x-1).

［式中、Ｒ^４”は、置換基を有していてもよいアルキル基、ハロゲン化アルキル基、アリール基またはアルケニル基を表す。］

[Wherein, R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group or an alkenyl group which may have a substituent.]

The alkyl group for R ⁴ ″ may be linear, branched or cyclic.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. The ring may be monocyclic or polycyclic, and specific examples include a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, an isobornyl group, a tricyclodecanyl group, and a tetracyclododecanyl group.
When R ⁴ ″ is an alkyl group, the acid strength is weak, but it can be suitably used for, for example, a negative resist composition.
Examples of the halogenated alkyl group for R ⁴ ″ include groups in which part or all of the hydrogen atoms of the linear, branched, or cyclic alkyl group have been substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. 50 to 100% is preferable, and 100% is most preferable. The higher the halogenation rate, the better the acid strength.
The aryl group for R ⁴ ″ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group in R ⁴ ″ is preferably an alkenyl group having 2 to 10 carbon atoms.

In the above R ⁴ ″, “optionally substituted” means that part or all of the hydrogen atoms in the alkyl group, halogenated alkyl group, aryl group, or alkenyl group are substituents (other than hydrogen atoms). Other atoms or groups) may be substituted.
The number of substituents in R ⁴ ″ may be one or two or more.
Examples of the substituent include, for example, a halogen atom, a hetero atom, an alkyl group, a formula: Z-Q ^1- [where Q ¹ is a divalent linking group containing an oxygen atom, and Z has a substituent. And a hydrocarbon group having 3 to 30 carbon atoms. ] Etc. which are represented by these.
Examples of the halogen atom include the same halogen atoms as those described above for the halogenated alkyl group mentioned for R ⁴ ″.
As the alkyl group, the same alkyl groups as those described above for R ⁴ ″ can be used.
Examples of the hetero atom include an oxygen atom (═O, —O—), a nitrogen atom, and a sulfur atom.

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

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

The aliphatic hydrocarbon group in Z may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In Z, the aliphatic hydrocarbon group may have a part of the carbon atoms constituting the aliphatic hydrocarbon group substituted with a substituent containing a hetero atom, and the hydrogen atom constituting the aliphatic hydrocarbon group May be substituted with a substituent containing a hetero atom.
The “heteroatom” in Z 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 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 carbon atoms include, for example, —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. -, - C (= O) -NH -, - NH- (H is an alkyl group, may be substituted with a substituent such as an acyl group), - S -, - S (= O) 2 -, - S (= O) ₂ —O— and the like can be mentioned. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent that substitutes part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic ring). Formula group) is preferred.
The linear saturated hydrocarbon group (alkyl group) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, 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, it is preferable that carbon number is 2-10, 2-5 are preferable, 2-4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the unsaturated hydrocarbon group is particularly preferably a propenyl group.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms 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.
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 one or more hydrogen atoms from the polycycloalkane are substituted. 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 —, wherein R ⁹⁴ and R ⁹⁵ are each independently carbon. An alkylene group of 1 to 5 and m is an integer of 0 or 1.]

In the formula, examples of the alkylene group for Q ″, R ⁹⁴ and R ⁹⁵ include the same alkylene groups as those described above for R ^{91 to} R ⁹³ .
In these aliphatic cyclic groups, a part of hydrogen atoms bonded to carbon atoms constituting the ring structure may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, particularly preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or 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, Z is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, the above (L2) to (L5), (S3) to (S4), and the like.

In the present invention, ^{R 4} "is, ^{Z-Q 1} - as a substituent when having, ^{R 4"} as ^{the, Z-Q 1 -Y 1 -} [ wherein, ^{Q 1} and Z are as defined above, Y ¹ is an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. ] Is preferable.
That, X ^- If there is a sulfonate anion is preferably an anion represented by the following general formula (x-11).

［式中、Ｑ^１は酸素原子を含む２価の連結基であり、Ｚは置換基を有していてもよい炭素数３〜３０の炭化水素基であり、Ｙ^１は置換基を有していてもよい炭素数１〜４のアルキレン基または置換基を有していてもよい炭素数１〜４のフッ素化アルキレン基である。］

[Wherein, Q ¹ is a divalent linking group containing an oxygen atom, Z is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, and Y ¹ has a substituent. Or an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. ]

In formula (x-11), Z and Q ¹ are the same as defined above.
Examples of the alkylene group for Y ¹ include the same alkylene groups as those described above for Q ¹ having 1 to 4 carbon atoms.
Examples of the fluorinated alkylene group 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 alkylene group or fluorinated alkylene group may have a substituent. An alkylene group or a fluorinated alkylene group has a “substituent” means that part or all of the hydrogen atom or fluorine atom in the alkylene group or fluorinated alkylene group is substituted with an atom or group other than a hydrogen atom and a fluorine atom. Means that
Examples of the substituent that the alkylene group or fluorinated alkylene group may have include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a hydroxyl group.

  Preferable examples of the anion represented by the formula (x-11) include anions represented by the following formulas (b1) to (b8).

［式中、ｐは１〜３の整数であり、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｒ１は０〜３の整数であり、ｇは１〜２０の整数であり、Ｒ^７は置換基であり、ｎ１〜ｎ５はそれぞれ独立に０または１であり、ｖ０〜ｖ５はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ５はそれぞれ独立に０〜３の整数であり、Ｑ”は前記と同じである。］

[Wherein, p is an integer of 1 to 3, q1 to q2 are each independently an integer of 1 to 5, r1 is an integer of 0 to 3, g is an integer of 1 to 20, R ⁷ is a substituent, n1 to n5 are each independently 0 or 1, v0 to v5 are each independently an integer of 0 to 3, w1 to w5 are each independently an integer of 0 to 3, Q ″ is the same as above.]

The substituent of R ^7, in the Z, aliphatic hydrocarbon group substituent which may be possessed, the same ones as exemplified as the aromatic hydrocarbon group substituent which may be optionally has Can be mentioned.
Code (r1, w1 to w5) attached to R ⁷ when is an integer of 2 or more, a plurality of the R ⁷ groups may be the same, respectively, it may be different.

Moreover, when X < ^- > is an imide anion, the anion represented by the following general formula (b-3) or (b-4) is mentioned.

［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、置換基を有していてもよいアルキル基、ハロゲン化アルキル基を表す。］

[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 have a substituent. Represents a good alkyl group or halogenated alkyl group.]

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.
The number of carbon atoms of the alkylene group of X ″ is preferably as small as possible because, for example, the solubility in a resist solvent is good within the range of the carbon number.
In the alkylene group of X ″, the larger the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid and the better the transparency to high energy light of 200 nm or less and electron beam. The proportion of fluorine atoms in the group or alkyl group, that is, the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably, a hydrogen atom in which all hydrogen atoms are substituted with fluorine atoms. A fluoroalkylene group or a perfluoroalkyl group;
Y ″ and Z ″ each independently represent an optionally substituted alkyl group or halogenated alkyl group.
The alkyl group in Y ″ and Z ″ may be linear, branched or cyclic, and examples thereof include the same as the alkyl group in R ⁴ ″.
Wherein Y ", Z" as the halogenated alkyl group in the straight-chain, part or all of the hydrogen atoms of the branched chain or cyclic alkyl group include groups substituted with halogen atoms, the R ⁴ And the same as the alkyl group in ”. In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) ) Is preferably 10 to 100%, more preferably 50 to 100%, and most preferably 100%, and the higher the halogenation rate, the more preferable the strength of the acid.
In Y ″ and Z ″, “may have a substituent” means that part or all of the hydrogen atoms in the alkyl group and halogenated alkyl group are substituents (other atoms other than hydrogen atoms). Or a group) may be substituted. The number of substituents in Y ″ and Z ″ may be one or two or more.
Examples of the substituent include, for example, a halogen atom, a hetero atom, an alkyl group, a formula: Z-Q ^1- [where Q ¹ is a divalent linking group containing an oxygen atom, and Z has a substituent. And a hydrocarbon group having 3 to 30 carbon atoms. ]
Examples of the halogen atom include the same halogen atoms as those described above for the halogenated alkyl group for R ⁴ ″.
As the alkyl group, the same alkyl groups as those described above for R ⁴ ″ can be used.
Examples of the heteroatom include the same heteroatoms as those exemplified as the alkyl group for R ⁴ ″.
Z-Q 1 ^- In the group represented by, Q ¹ represents a divalent linking group containing an oxygen atom.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond; —O—), an ester bond (—C (═O) —O—), and a carbonyl group (—C (═O) —). And non-hydrocarbon oxygen atom-containing linking groups such as carbonate bonds (—O—C (═O) —O—); combinations of the non-hydrocarbon oxygen atom-containing linking groups and alkylene groups, and the like.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) — (wherein R ^{91 to} R ⁹² are each independently an alkylene group).
The alkylene group for R ⁹¹ to R ^92, preferably a linear or branched alkylene group, the carbon number of the alkylene group having 1 to 12, more preferably 1 to 5, especially 1 to 3 preferable. Specifically, it is the same as the alkylene group of R ^{91 to} R ⁹² in R ^{4 ″} .
Q ¹ is preferably a divalent linking group containing an ester bond or an ether bond.
In the group represented by Z—Q ¹ —, the hydrocarbon group for Z is the same as the alkylene group for R ^{91 to} R ⁹² in R ^{4 ″} above. Preferably, it is an aliphatic hydrocarbon group, A chain or cyclic aliphatic hydrocarbon group is more preferable.
Preferable examples of the anion when formula (b-4) has ZQ ¹ — as a substituent include anions represented by the following formulas (b4-1) to (b4-11).

［式中、ｇは１〜４の整数であり、ｔ１〜ｔ５は１〜４の整数であり、ｍ_１〜ｍ_５は０又は１であり、ｗ１”〜ｗ４”はそれぞれ独立に０〜３の整数であり、Ｒ^２１〜Ｒ^２４は置換基である

[Wherein, g is an integer of 1 to 4, t1 to t5 are integers of 1 to 4, m _{1 to} m ₅ are 0 or 1, and w1 ″ to w4 ″ are each independently 0 to 3 And R ^{21 to} R ²⁴ are substituents.

g is an integer of 1-4 independently, 1 or 2 is preferable and 1 is the most preferable.
t1 to t5 are each independently an integer of 1 to 4, preferably 1 or 2, and most preferably 2.
m _{1 to} m ₅ are each independently 0 or 1, and 0 is preferable.
w1 ″ to w4 ″ are each independently an integer of 0 to 3, preferably 0 or 1, and most preferably 0.
Examples of the substituent for R ^{21 to} R ²⁴ include the same substituents as those described above as the substituent that the aliphatic hydrocarbon group may have in Z in the above formula: ZQ ^1- .
When the symbols (w1 ″ to w4 ″) attached to R ^{21 to} R ²⁴ are integers of 2 or more, the plurality of R ^{21 to} R ²⁴ in the compound may be the same or different. Good.
In the above Y ″ and Z ″, when one is an alkyl group and the other is a fluorinated alkyl group, —SO ₂ — bonded to the alkyl group may be substituted with —C (═O) —. . Examples of the alkyl group include those similar to the above-mentioned R ⁴ ″, and preferred specific examples include those having a cyclic alkyl group; for example, a methyladamantyl group, an adamantyl group and the like.
Moreover, when X < ^- > is a metide anion, the anion represented by the following general formula (b-c1) is mentioned.

［式中、Ｒ^１は、少なくとも１の水素原子がフッ素置換されている炭素数１〜１０のアルキル基であり；Ｒ^２は、置換基を有していてもよい炭化水素基、または−ＳＯ_２−Ｒ^１である。］
式（ｂ−ｃ１）中、Ｒ^１は、少なくとも１の水素原子がフッ素置換されている炭素数１〜１０のアルキル基である。当該アルキル基としては、直鎖状、分岐鎖状、環状のいずれであってもよい。本発明におけるＲ^１としては、直鎖状または分岐鎖状のアルキル基であることが好ましく、直鎖状のアルキル基であることがより好ましい。
式（ｂ−ｃ１）において、Ｒ^２が置換基を有していてもよい炭化水素基の場合（なお、「置換基を有していてもよい炭化水素基」とは、当該炭化水素基を構成する水素原子の一部または全部が置換基で置換されていてもよいことを意味する）Ｒ^２の炭化水素基は、脂肪族炭化水素基であってもよく、芳香族炭化水素基であってもよい。具体的には、上記式：Ｚ−Ｑ^１−におけるＺと同様である。
Ｒ^２として好ましくは、ハロゲン化アリール基であり、炭素数６〜１０のアリール基、たとえばフェニル基、ナフチル基等のアリール基の水素原子の一部または全部が前記ハロゲン原子（より好ましくはフッ素原子）で置換された基が挙げられる。
また、Ｘ⁻がハロゲンアニオンである場合は、Ｘ⁻として、フッ素アニオン、塩素アニオン、臭素アニオン、ヨウ素アニオンが挙げられる。

[Wherein R ¹ is an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with fluorine; R ² is a hydrocarbon group which may have a substituent, or —SO 2 it is a ₂ -R ^1. ]
In formula (b-c1), R ¹ is an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with fluorine. The alkyl group may be linear, branched or cyclic. R ¹ in the present invention is preferably a linear or branched alkyl group, and more preferably a linear alkyl group.
In the formula (b-c1), when R ² is an optionally substituted hydrocarbon group (the “optionally substituted hydrocarbon group” means the hydrocarbon group The hydrocarbon group of R ² may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group (meaning that part or all of the constituent hydrogen atoms may be substituted with a substituent). May be. Specifically, it is the same as Z in the above formula: ZQ ^1- .
R ² is preferably a halogenated aryl group, and a part or all of hydrogen atoms of an aryl group having 6 to 10 carbon atoms, for example, a phenyl group, a naphthyl group, or the like is the halogen atom (more preferably a fluorine atom). ).
When X ⁻ is a halogen anion, examples of X ⁻ include a fluorine anion, a chlorine anion, a bromine anion, and an iodine anion.

In the present invention, as X ⁻ , among the above, R ⁴ ″ in the general formula (x-1) has an anion which is a fluorinated alkyl group which may have a substituent, that is, has a substituent. Preferred are fluorinated alkyl sulfonate ions.
Examples of the fluorinated alkyl group which may have a substituent include those in which part or all of the hydrogen atoms of the alkyl group mentioned as the alkyl group for R ⁴ ″ are substituted with fluorine atoms. Since an alkyl group having 6 or more carbon atoms or a fluorinated alkyl group is hardly decomposable, those having 4 or less carbon atoms such as nonafluorobutane sulfonate ion are particularly preferable from the viewpoint of handling safety considering bioaccumulation. preferable.

As the component (B1), one type may be used alone, or two or more types may be used in combination.
In the component (B), the ratio of the component (B1) is preferably 1 to 100% by mass, more preferably 20 to 100% by mass, and still more preferably 50 to 100% by mass.

In the general formula (b1-14), X ⁻ may be a halogen anion. Here, examples of the halogen anion include fluoride ion, chloride ion, bromide ion, and iodide ion.

Specific examples of X ^{− in} the above (b1-14) are shown below.

  Specific examples of the compound of the third aspect of the present invention include the following compounds (b1-14-1) to (b1-14-30) and compounds shown in the synthesis examples described later.

<Method for Producing Compound of Third Aspect>
The compound (b1-14) of the third aspect of the present invention can be produced, for example, as follows. That is, the following general formulas (b1-14-01) and (b1-14) are contained in a solution of an organic acid H ⁺ B ⁻ (B ⁻ represents an anion part of an organic acid such as methanesulfonate ion). −02) and the reaction is carried out, and then pure water and an organic solvent (for example, dichloromethane, tetrahydrofuran, etc.) are added to recover the organic layer. From the organic layer, the following general formula (b1- 14-03) is obtained.
Next, the compound represented by the general formula (b1-14-03) is dissolved in a mixed solvent of an organic solvent (for example, dichloromethane, tetrahydrofuran, etc.) and water, and an alkali metal salt of a desired anion X ⁻ is dissolved therein. L ⁺ X ⁻ (L ⁺ represents an alkali metal cation such as lithium ion, potassium ion, sodium ion, etc.) is added and reacted, followed by liquid separation and washing with water, then the following general formula (b1 The compound represented by -14-04) is obtained.
Next, the compound represented by the general formula (b1-14-04) is dissolved in an organic solvent (for example, dichloromethane, tetrahydrofuran and the like), ice-cooled, a base (for example, sodium hydride and the like) is added, and the desired compound is added. Alkoxycarbonylalkyl group halides (for example, the general formula “Cl—R ⁵⁰ —C (═O) —O—R ⁵¹ ”, “Br—R ⁵⁰ —C (═O) —O—R ⁵¹ ”, etc.) And R ^{50 to} R ⁵¹ are the same as above, and the hydrogen atom of the —OH group of —R ¹⁰ ″ —OH is substituted with the alkoxycarbonylalkyl group, whereby the compound (b1-14) is obtained. can get.

［式中、Ｒ^８”およびＲ^９”は前記一般式（ｂ１−１４）中のＲ^８”およびＲ^９”と同様であり；Ｒ^１０”は前記一般式（ｂ１−１４）中のアリール基であるＲ^７”から１つの水素原子を除いたアリーレン基であり；Ｂ⁻は、有機酸のアニオン部であり；Ｌ^＋は、アルカリ金属カチオンであり；Ｘ⁻は、前記一般式（ｂ１−１４）中のＸ⁻と同様である。］
また、化合物（ｂ１−１４−０３）のアニオン交換について、Ｌ^＋Ｘ⁻と反応させる前に化合物（ｂ１−１４−０３）の−Ｒ^１０” −ＯＨの−ＯＨ基の水素原子を前記アルコキシカルボニルアルキル基と置換してから、アニオン交換を行うことによっても、化合物（ｂ１−１４）を得ることができる。

Wherein, ^{R 8} "and ^{R 9"} is the same as ^{R 8} "and ^{R 9"} in the general formula ^{(b1-14); R 10} "is an aryl group in the general formula (b1-14) R ⁷ ″ is an arylene group obtained by removing one hydrogen atom; B ⁻ is an anion portion of an organic acid; L ⁺ is an alkali metal cation; and X ⁻ is the general formula (b1- 14) in the X ^- it is the same as. ]
In addition, regarding the anion exchange of the compound (b1-14-03), the hydrogen atom of the —OH group of —R ¹⁰ ″ —OH of the compound (b1-14-03) is replaced with the alkoxycarbonyl before reacting with L ⁺ X ^—. The compound (b1-14) can also be obtained by performing anion exchange after substitution with an alkyl group.

<< Acid generator of the fourth aspect >>
The acid generator of the fourth aspect of the present invention (hereinafter sometimes referred to as an acid generator (B1)) is composed of a compound represented by the general formula (b1-14). In the formula, R ⁷ ″ to R ⁹ ″ and X ⁻ are the same as those described in the compound of the third aspect of the present invention.

<< Resist Composition of First Aspect >>
Next, the resist composition according to the first aspect of the present invention will be described. The resist composition according to the first aspect of the present invention comprises a substrate component (A) whose solubility in an alkaline developer is changed by the action of an acid (hereinafter referred to as component (A)) and an acid that generates an acid upon exposure. It contains a generator component (B) (hereinafter referred to as component (B)), and the component (B) contains an acid generator (B1) composed of a compound represented by the general formula (b1-14). It is a waste.

In the resist composition of the present invention, as the component (A), a polymer material whose solubility in an alkali developer is changed by the action of an acid can be used, and the solubility in an alkali developer is changed by the action of an acid. Low molecular weight materials can also be used.
The resist composition of the present invention may be a negative resist composition or a positive resist composition.
When the resist composition of the present invention is a negative resist composition, for example, the component (A) is an alkali-soluble resin, and a crosslinking agent (C) is further blended in the negative resist composition.
In such a negative resist composition, when an acid is generated from the component (B) by exposure at the time of resist pattern formation, the exposed portion acts to cause crosslinking between the alkali-soluble resin and the crosslinking agent. Change to insoluble.
As the alkali-soluble resin, a resin having a unit derived from at least one selected from α- (hydroxyalkyl) acrylic acid or a lower alkyl ester of α- (hydroxyalkyl) acrylic acid is a good resist with little swelling. A pattern can be formed, which is preferable. Α- (Hydroxyalkyl) acrylic acid includes acrylic acid in which a hydrogen atom is bonded to the α-position carbon atom to which the carboxy group is bonded, and a hydroxyalkyl group (preferably having 1 carbon atom) in the α-position carbon atom. One or both of [alpha] -hydroxyalkylacrylic acids to which (5) hydroxyalkyl groups) are attached.
As the crosslinking agent (C), 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 little swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent (C) 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, the component (A) is insoluble in an alkali developer before exposure, and is generated from the component (B) by exposure at the time of resist pattern formation. When the acid acts, the acid dissociable, dissolution inhibiting group is dissociated, thereby increasing the solubility of the entire component (A) in the alkali developer, and changing from alkali-insoluble to alkali-soluble. 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 part turns to alkali-soluble while the unexposed part is alkali-insoluble. Since it remains unchanged, alkali development can be performed.

  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) is more preferably a resin component (A1) (hereinafter referred to as the component (A1)) whose alkali solubility is increased by the action of an acid.

<(A1) component>
The component (A1) preferably used in such a positive resist composition preferably has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
The component (A1) preferably further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.
The component (A1) preferably further has a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.

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 linear or branched lower 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. Here, 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 particularly preferable.

・ Structural unit (a1)
The structural unit (a1) is a structural unit derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
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.
In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal-type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. . The “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position.

Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (O)). A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of -O-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom.
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.

Here, “aliphatic” in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean a group, a compound, or the like that does not have aromaticity.
“Aliphatic branched” means having a branched structure having no aromaticity.
The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group.
The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
As the aliphatic branched acid dissociable, dissolution inhibiting group, a tertiary alkyl group having 4 to 8 carbon atoms is preferable, and specific examples include a tert-butyl group, a tert-pentyl group, and a tert-heptyl group. .

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a1) may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The “aliphatic cyclic group” is preferably a polycyclic group.
Examples of the aliphatic cyclic group include monocycloalkanes, bicycloalkanes, tricycloalkanes, tetracycloalkanes which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. And groups obtained by removing one or more hydrogen atoms from a polycycloalkane. 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 each} represents an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms. Is). ]

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

The “acetal-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, the acid acts to break the bond between the acetal acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal acid dissociable, dissolution inhibiting group is bonded.
Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (p1).

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

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

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

［式中、Ｒ^１’、ｎ、Ｙは上記と同様である。］

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

Examples of the lower alkyl group for Y include the same lower alkyl groups as those described above for R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups conventionally proposed in a number of ArF resists and the like. 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または分岐鎖状のアルキル基または水素原子であり、Ｒ^１９は直鎖状、分岐鎖状または環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状または分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

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

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

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

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

In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).
Y ² is preferably an alkylene group having 1 to 10 carbon atoms or a divalent aliphatic cyclic group, and the aliphatic cyclic group is the above except that a group in which two or more hydrogen atoms are removed is used. The thing similar to description of an "aliphatic cyclic group" can be used.

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

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

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

In the R ¹ ′ and R ² ′, at least one is preferably a hydrogen atom, and more preferably both are hydrogen atoms. n is preferably 0 or 1.

X ′ is the same as the tertiary alkyl ester type acid dissociable, dissolution inhibiting group exemplified in X ¹ above.
Examples of the aliphatic cyclic group for Y include the same groups as those exemplified above in the explanation of “aliphatic cyclic group”.
Y ² is preferably an alkylene group having 1 to 10 carbon atoms or 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 an alkylene group having 1 to 10 carbon atoms, it is more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. . When Y ² is a divalent aliphatic cyclic group, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, or tetracyclododecane is particularly preferable. .

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

In the above formula, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
Among these, the structural unit represented by general formula (a1-1) or (a1-3) is preferable, and specifically, (a1-1-1) to (a1-1-4), (a1-1-1-) It is more preferable to use at least one selected from the group consisting of 20) to (a1-1-23) and (a1-3-25) to (a1-3-28).
Furthermore, as the structural unit (a1), those represented by the following general formula (a1-1-01) including particularly the structural units of the formula (a1-1-1) to the formula (a1-1-3), In the following general formula (a1-1-02) including the structural units of formulas (a1-1-16) to (a1-1-17) and formulas (a1-1-20) to (a1-1-23) Those represented are also preferred.

［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.

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

・ Structural unit (a2)
The structural unit (a2) is a structural unit 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. When only the lactone ring is present, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure.
When the component (A1) is used for forming a resist film, the lactone cyclic group of the structural unit (a2) increases the adhesion of the resist film to the substrate or has an affinity for a developer containing water. It is effective in raising.

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、または炭素数１〜５のアルコキシ基であり、ｍは０または１の整数であり、Ａは炭素数１〜５のアルキレン基または酸素原子である。］

[Wherein, R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ′ is a hydrogen atom, a lower alkyl group, or an alkoxy group having 1 to 5 carbon atoms, and m is an integer of 0 or 1] And A is an alkylene group having 1 to 5 carbon atoms or an oxygen atom. ]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
The lower alkyl group for R ′ is the same as the lower alkyl group for R in the structural unit (a1).
Specific examples of the alkylene group having 1 to 5 carbon atoms of A include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.
Below, the specific structural unit of the said general formula (a2-1)-(a2-5) is illustrated.

  Among these, it is preferable to use at least one selected from general formulas (a2-1) to (a2-5), and at least one selected from general formulas (a2-1) to (a2-3). It is preferable to use more than one species. Specifically, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-2), (a2-3-1), (a2-3) -2), at least one selected from (a2-3-9) and (a2-3-10) is preferably used.

In the component (A1), as the structural unit (a2), one type of structural unit may be used, or two or more types may be used in combination.
The proportion of the structural unit (a2) in the component (A1) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, with respect to the total of all the structural units constituting the component (A1). More preferred is mol%. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) is 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 (A) 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, structural units represented by the following formulas (a3-1) to (a3-4) are preferable.

［式中、Ｒは前記と同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数であり、ｄは１〜３の整数であり、ｅは０または１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] S is an integer of 1 to 3, d is an integer of 1 to 3, and e is 0 or 1. ]

In the general formulas (a3-1) to (a3-4), 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. Same as the group.
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.

  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.
In formula (a3-4), d is preferably 1 or 2, and more preferably 1. The bonding position of the hydroxyl group is not particularly limited, and when d is 1, the 2nd position is preferable because it is readily available and inexpensive. When d is 2 or 3, arbitrary substitution positions can be combined.

In the component (A1), as the structural unit (a3), one type of structural unit may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a3) in the component (A1) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on all the structural units constituting the component (A1). 25 mol% 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 that is not classified into the structural units (a1) to (a3) described above, and is for ArF excimer laser and KrF excimer laser (preferably ArF excimer). A number of hitherto known materials can be used for resist resins such as lasers.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

［式中、Ｒは前記と同じである。］

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

In the general formulas (a4-1) to (a4-5), the lower alkyl group or halogenated lower alkyl group represented by R is a lower alkyl group or halogenated lower group which may be bonded to the α-position of the acrylate ester. It is the same as the alkyl group.
When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1). 10 to 20 mol% is more preferable.

  In the present invention, the component (A1) is a resin component (polymer) whose solubility in an alkali developer is increased by the action of an acid. Examples of suitable resin components (polymers) include structural units. A copolymer having (a1), (a2) and (a3), and examples of such a copolymer include a copolymer composed of structural units (a1), (a2) and (a3), structural units ( Examples thereof include a copolymer comprising a1), (a2), (a3) and (a4).

As the component (A1), one type may be used alone, or two or more types may be used in combination.
In the present invention, as the component (A1), the copolymers (A1-1) to (A1-) containing combinations of structural units represented by the following general formulas (A1-1) to (A1-4) 4) is preferred.

［式中、Ｒは前記と同様であり、複数のＲはそれぞれ同じであっても異なっていても良い。Ｒ^２０、Ｒ^２１”は低級アルキル基である。］

[Wherein, R is the same as defined above, and a plurality of R may be the same or different. R ²⁰ and R ^{21 ″} are lower alkyl groups.]

In the formula, R is the same as described above, and among them, a hydrogen atom or a methyl group is preferable.
In the formula, R ²⁰ is a lower alkyl group, preferably a methyl group or an ethyl group.
In the formula, R ^{21 ″} is a lower alkyl group, preferably a methyl group or an ethyl group.

In the component (A), as the copolymers (A1-1) to (A1-4), one type may be used alone, or two or more types may be used in combination.
And when using combining 2 or more types among copolymer (A1-1)-(A1-4), as a preferable combination of a copolymer, a copolymer (A1-2) and a copolymer ( A combination of A1-3) can be exemplified.
The content of the copolymers (A1-1) to (A1-4) in the component (A) is preferably 70% by mass or more, more preferably 80% by mass or more, and 100% by mass. There may be. Especially, it is most preferable that it is 100 mass%. By being above the lower limit of the range, the lithography properties are further improved when a positive resist composition is obtained.

The component (A1) is obtained by polymerizing a monomer for deriving each structural unit by known radical polymerization using an azo radical polymerization initiator such as azobisisobutyronitrile (AIBN). Can do.
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 into which a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom is introduced has reduced 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 4000 to 20000. Particularly preferred is 5000 to 20000. Within this range, there is sufficient solubility in a resist solvent for use as a resist, and 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.
Further, as the component (A1), an alkali-soluble resin component other than the copolymers (A1-1) to (A1-4), for example, other polymer compounds used in conventional positive resist compositions, and the like are used. You can also.
In the positive resist composition of the present invention, the content of the component (A1) may be appropriately adjusted according to the resist film thickness to be formed.

<(B) component>
In the resist composition of the present invention, the component (B) contains an acid generator (B1) (hereinafter referred to as the component (B1)) composed of the compound represented by the general formula (b1-14).
In the formula, R ⁷ ″ to R ⁹ ″ and X ⁻ are the same as those described in the compound of the third aspect of the present invention.
When component (B) contains component (B1), mask reproducibility when a resist pattern is formed, for example, roundness and diameter of the hole when a contact hole (C / H) pattern is formed (CD) uniformity (CDU) is improved, mask error factor (MEF) is improved, and the C / H pattern is easily removed, so that lithography characteristics are improved. Further, when a line-and-space resist pattern (L / S pattern) is formed, the MEF is improved and the lithography characteristics are improved.
The resist composition of the present invention can be suitably used as a resist composition for immersion exposure in a resist pattern forming method including an immersion exposure step, and can provide good lithography characteristics. In a resist pattern forming method including a step of forming a laminate, it can be suitably used as a positive resist composition for forming an upper resist film, and good lithography characteristics can be obtained.
(B1) as the component, the general formula as the anion portion ^"R 4" -SO ₃ ^- "or" _{^{Z-Q 1 -Y 1 -SO 3}} - "anion and represented by the general formula (b-3 ) Or an anion represented by (b-4) is preferable because the lithography properties are improved. Then, the general formula ^"R 4" -SO ₃ ^- "or" _{^{Z-Q 1 -Y 1 -SO 3}} - "further preferably an anion represented by.

(B) 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 entire component (B) is preferably 40% by mass or more, more preferably 60% by mass or more, and may be 100% by mass. By being at least the lower limit of the range, the resist pattern shape is good. In particular, when a resist pattern is formed using a resist composition for immersion exposure or a resist composition for forming an upper resist film, the lithography characteristics are improved. When forming a three-layer resist laminate, it is preferable because matching with the lower layer film of the resist is good, and resist pattern tailing and the like can be suppressed.
Moreover, in the resist composition of this invention, it is preferable that content of (B1) component is 1-30 mass parts with respect to 100 mass parts of said (A) component, and is 3-18 mass parts. Is particularly preferable, and is most preferably 5 to 16 parts by mass. By being at least the lower limit of the range, lithography characteristics are improved particularly when a resist pattern is formed using a resist composition for immersion exposure or a resist composition for forming an upper resist film. On the other hand, storage stability will become favorable by being below an upper limit.

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, and poly (bissulfonyl) diazomethanes. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.

  As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく；Ｒ^４”は、直鎖状、分岐鎖状または環状のアルキル基またはフッ素化アルキル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

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

In the formula (b-1), R ¹ ″ to R ³ ″ are R ⁷ in the general formula (b1-14), except that the alkoxycarbonylalkyloxy group is not substituted with a hydrogen atom. The same as “˜R ⁹ ”.
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 of R ¹ ″ to R ³ ″ are aryl groups.
R ¹ ″ to R ³ ″ are most preferably a phenyl group or a naphthyl group.

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. It is preferable because the strength of the acid is increased.
R ⁴ ″ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

In formula (b-2), R ⁵ ″ and R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferred that both R ⁵ ″ and R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ and 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 ″ and R ⁶ ″ include the same alkyl groups as those for R ¹ ″ to R ³ ″.
Of these, it is most preferred that both R ⁵ ″ and R ⁶ ″ are phenyl groups.
"As ^{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. Trifluoromethanesulfonate or nonafluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorobutanesulfonate, tri (4-methylphenyl) sulfonium trifluoromethanesulfonate, heptafluoropropanesulfonate or the same 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) phenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1-phenyltetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate 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 acid generator in which the anion moiety is replaced with the anion moiety represented by the general formula (b-3) or (b-4). Can also be used (the cation moiety is the same as (b-1) or (b-2)).

  Moreover, the sulfonium salt which has a cation part represented by the following general formula (b-5) or (b-6) can also be used as an onium salt type | system | group acid generator.

［式中、Ｒ^４１〜Ｒ^４６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_１〜ｎ_５はそれぞれ独立して０〜３の整数であり、ｎ_６は０〜２の整数である。］

[Wherein R ^{41 to} R ⁴⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n _{1 to} n ₅ are each independently an integer of 0 to 3; There, _{n 6} is an integer of 0-2. ]

In R ^{41 to} R ⁴⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group, an isopropyl group, Particularly preferred is an n-butyl group or a tert-butyl group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n _{1 to} n ₆ attached to R ^{41 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{41 to} R ⁴⁶ may be the same or different.
n ₁ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.

The anion part of the sulfonium salt having a cation part represented by the formula (b-5) or (b-6) is not particularly limited, and is the same as the anion part of the onium salt acid generators proposed so far. It may be a thing. Examples of the anion moiety include fluorinated alkyl sulfonate ions such as the anion moiety (R ^{4 ″} SO ₃ ⁻ ) of the onium salt acid generator represented by the general formula (b-1) or (b-2). An anion moiety represented by the above general formula (b-3) or (b-4), etc. Among these, a fluorinated alkylsulfonic acid ion is preferable, and a fluorinated alkylsulfonic acid having 1 to 4 carbon atoms. Ion is more preferable, and linear perfluoroalkylsulfonic acid ions having 1 to 4 carbon atoms are particularly preferable, and specific examples thereof include trifluoromethylsulfonic acid ions, heptafluoro-n-propylsulfonic acid ions, and nonafluoro-n. -Butyl sulfonate ion etc. are mentioned.

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

［式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。］

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

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

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

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

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

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

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

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

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

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

The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups having no substituent as R ³⁵ described above.
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.
Also, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), WO 2004 / 074242A2 (pages 65 to 85). The oxime sulfonate acid generators disclosed in Examples 1 to 40) of No. 1 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

  Of the above exemplified compounds, the following four compounds are preferred.

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.

<(D) component>
In the resist composition of the present invention, a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) is further blended as an optional component in order to improve the resist pattern shape, stability over time, etc. be able to.
Since a wide variety of components (D) have already been proposed, any known one may be used. Among them, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are used. preferable. Here, “aliphatic” in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean a group, a compound, or the like that does not have aromaticity.
The “aliphatic cyclic group” means a monocyclic group or polycyclic group having no aromaticity. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, and the like; diethanolamine, triethanolamine, diisopropanolamine Triisopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, tri-n-pentylamine and tri-n-octylamine are particularly preferable, and tri-n-pentylamine is most preferable.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

<Optional component> [(E) component]
The resist composition of the present invention comprises an organic carboxylic acid, a phosphorus oxo acid, and derivatives thereof as optional components for the purpose of preventing sensitivity deterioration and improving the resist pattern shape and stability with time. 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.

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

[(S) component]
The resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond 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), ethyl lactate (EL), and γ-butyrolactone are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
Furthermore, as the component (S), a mixed solvent of the above-described mixed solvent of PGMEA and PGME and γ-butyrolactone is also preferable. In this case, as a mixing ratio, the mass ratio of the former and the latter is preferably 99.9: 0.1 to 80:20, more preferably 99.9: 0.1 to 90:10, Most preferably, it is 99.9: 0.1-95: 5.
By setting it as the said range, the rectangularity of a resist pattern improves.
The amount of component (S) used is not particularly limited, but it 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.

In this invention, the acid generator (B1) which consists of a compound represented by the said general formula (b1-14) is used. The component (B1) has a structure in which the hydroxyl group bonded to the aryl group is protected with a tertiary alkyl ester type acid dissociable group, and the structure is not changed in the non-exposed area. Therefore, it is considered that the compound represented by the general formula (b1-14) exhibits a dissolution inhibiting effect on the alkali developer with respect to the component (A1) in the non-exposed portion of the resist film.
On the other hand, in the exposed area, during the post-exposure heating (PEB) with the generated acid, the acid dissociable group is dissociated from the oxygen atom constituting the hydroxyl group, resulting in a compound in which the hydroxyl group is bonded to the aryl group, It is considered that the component (A1) exhibits an effect of promoting dissolution in an alkali developer.
Therefore, it is considered that high contrast of the exposed part / non-exposed part can be achieved. Also, by having a monocyclic group-containing tertiary alkyl group in the cation part, a good resist pattern shape can be obtained. PEB Sensitivity will be good.
The reason is not clear, but a decomposition product derived from a monocyclic group-containing tertiary alkyl group disappears from the film in PEB, and the plastic effect can be suppressed. By suppressing the plastic effect, it is possible to suppress a decrease in Tg (glass transition temperature) in the resist film, and to suppress diffusion of the acid generator. As a result, the resist pattern shape, particularly LWR, is good. .

For the above reasons, when the resist composition of the present invention is a positive resist composition, a resist pattern is formed by using a combination of a base material component and an acid generator (the (B1) component). It is presumed that lithography characteristics are improved, such as improvement of LWR and PEB Sensitivity at the time.
The resist composition of the present invention can be suitably used as a resist composition for immersion exposure in a resist pattern forming method including an immersion exposure step, and can provide good lithography characteristics. In a resist pattern forming method including a step of forming a laminate, it can be suitably used as a positive resist composition for forming an upper resist film, and it is considered that good lithography characteristics can be obtained.

≪Resist pattern formation method≫
Next, the resist pattern forming method of the second aspect of the present invention will be described.
The resist pattern forming method of the present invention includes a step of forming a resist film on a support using the resist composition of the first aspect of the present invention, a step of exposing the resist film, and an alkali development of the resist film. Then, the method includes a step of forming a resist pattern.

  A preferred example of the method for forming a resist pattern of the present invention is shown below by taking as an example the case where the resist film is exposed by immersion exposure. However, the present invention is not limited to this, and the exposure may be performed by normal exposure (dry exposure) performed in an inert gas such as air or nitrogen.

First, after applying the resist composition of the present invention on a support with a spinner or the like, a resist film is formed by performing pre-baking (post-apply baking (PAB) treatment).
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. In addition, a support in which an inorganic and / or organic film is provided on the above-described substrate may be used. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include organic films such as an organic antireflection film (organic BARC) and a lower organic film in a multilayer resist method.
Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the resist pattern formed on the upper resist film is used as a mask. This is a method of patterning a lower organic film, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, the required thickness can be secured by the lower organic film, so that the resist film can be thinned and a fine pattern with a high aspect ratio can be formed. In the multilayer resist method, basically, a method of forming a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and one or more intermediate layers between the upper resist film and the lower organic film And a method of forming a multilayer structure of three or more layers (metal thin film etc.) (three-layer resist method).
After the resist film is formed, an organic antireflection film may be further provided on the resist film to form a three-layer laminate including a support, a resist film, and an antireflection film. The antireflection film provided on the resist film is preferably soluble in an alkali developer.
The steps so far can be performed using a known method. The operating conditions and the like are preferably set as appropriate according to the composition and characteristics of the resist composition to be used.

Next, liquid immersion lithography is selectively performed on the resist film obtained above through a desired mask pattern. At this time, the space between the resist film and the lens at the lowest position of the exposure apparatus is previously filled with a solvent (immersion medium) having a refractive index larger than that of air, and exposure (immersion exposure) is performed in this state.
The wavelength used for the exposure is not particularly limited, and can be performed using radiation such as an ArF excimer laser, a KrF excimer laser, or an F ₂ laser. The resist composition according to the present invention is effective for a KrF or ArF excimer laser, particularly an ArF excimer laser.
As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of a resist film formed using the resist composition of the present invention 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.).
In the present invention, water is preferably used as the immersion medium because the resist composition of the present invention is not particularly susceptible to the adverse effects of water and is excellent in lithography properties such as sensitivity and resist pattern shape. Water is also preferable from the viewpoints of cost, safety, environmental problems, and versatility.

Next, after the immersion exposure step, post-exposure heating (post-exposure baking (PEB)) is performed. PEB is usually applied at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 to 90 seconds.
Subsequently, development is performed using an alkaline developer composed of an alkaline aqueous solution, for example, a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
After the development, water rinsing is preferably performed using pure water. The water rinsing can be performed, for example, by dropping or spraying water on the surface of the support while rotating the support to wash away the developer on the support and the resist composition dissolved by the developer.
Next, drying is performed to obtain a resist pattern in which a resist film (resist composition coating film) is patterned into a shape corresponding to the mask pattern.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. In the analysis by NMR, the internal standard of ¹ H-NMR is tetramethylsilane, and the internal standard of ¹⁹ F-NMR is hexafluorobenzene (however, the peak of hexafluorobenzene is -160 ppm).

(Synthesis Example 1) <Synthesis of Compound A>
Under a nitrogen atmosphere, Compound 1 (8.2 g) and dichloromethane (82 g) were added to a three-necked flask and cooled to 5 ° C. or lower. N, N-dimethylaminopyridine (0.46 g) was added thereto and stirred at 5 ° C. or lower for 5 minutes, and then ethyl-N, N-dimethylaminopropylcarbodiimide (3.9 g) was added. After stirring for 10 minutes, Compound 2a (4.3 g) was added. After completion of the addition, the mixture was warmed to room temperature, stirred at room temperature for 15 hours, then washed with diluted hydrochloric acid and washed with pure water. The organic phase was dropped into n-hexane (1000 g) and reprecipitated to obtain Compound A (5.0 g).
The results of analyzing the obtained compound by NMR are shown below.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.76-7.82 (m, 10H, ArH), 7.59 (s, 2H, ArH), 4.55 (s, 2H) , CH ₂ ), 2.29 (m, 6H, CH ₃ ), 1.90-1.93 (m, 4H, OCCH ₂ + cyclopropyl), 1.48-1.75 (m, 6H, cyclopentyl), 0 _{.77-0.81 (t, 3H, CH 3} ).
From the results described above, it was confirmed that the compound A had a structure shown below.

(Synthesis Example 2) <Synthesis of Compound A-1>
Compound A (2.2 g), dichloromethane (18.8 g) and pure water (7.1 g) were mixed, potassium perfluorobutanesulfonate (2.5 g) was added thereto, and the mixture was stirred overnight at room temperature. Thereafter, the organic phase was separated, and the organic phase was further washed four times with pure water (7.1 g). Then, dichloromethane was distilled off under reduced pressure, and the compound A-1 (2.8g) was obtained by drying under reduced pressure.
The results of analyzing the obtained compound by NMR are shown below.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.76-7.82 (m, 10H, ArH), 7.59 (s, 2H, ArH), 4.55 (s, 2H , CH ₂ ), 2.29 (m, 6H, CH ₃ ), 1.90-1.93 (m, 4H, OCCH ₂ + cyclopropyl), 1.48-1.75 (m, 6H, cyclopropyl), 0 _{.77-0.81 (t, 3H, CH 3} ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 77.3, −111.5, −118.1, −122.4.
From the results shown above, it was confirmed that the compound A-1 had a structure shown below.

(Synthesis Examples 3 to 24) <Synthesis of Compounds A-2 to A-23>
In the said synthesis example 2, it carried out by the same method except having changed perfluorobutanesulfonic-acid potassium salt into the salt shown in the following Tables 1-6, respectively (equimolar amount), and synthesize | combining.

(Synthesis Example 25) <Synthesis of Compound B>
Under a nitrogen atmosphere, Compound 1 (4.8 g) and dichloromethane (48 g) were added to a three-necked flask and cooled to 5 ° C. or lower. N, N-dimethylaminopyridine (0.27 g) was added thereto and stirred at 5 ° C. or lower for 5 minutes, and then ethyl-N, N-dimethylaminopropylcarbodiimide (2.3 g) was added. After stirring for 10 minutes, Compound 2b (2.2 g) was added. After completion of the addition, the mixture was warmed to room temperature, stirred at room temperature for 15 hours, then washed with diluted hydrochloric acid and washed with pure water. The organic phase was added dropwise to n-hexane (520 g) and reprecipitated to obtain Compound B (4.0 g).

The results of analyzing the obtained compound by NMR are shown below.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.76-7.82 (m, 10H, ArH), 7.59 (s, 2H, ArH), 4.55 (s, 2H _{, CH 2), 2.29 (m} , 6H, CH 3), 1.90-2.08 (m, 2H, cyclopentyl), 1.48-1.75 (m, 9H, OCCH 3 + cyclopentyl)
From the results described above, it was confirmed that the compound B had the structure shown below.

  Compound B (2.5 g), dichloromethane (18.8 g) and pure water (7.1 g) were mixed, potassium perfluorobutanesulfonate (2.5 g) was added thereto, and the mixture was stirred overnight at room temperature. Thereafter, the organic phase was separated, and the organic phase was further washed four times with pure water (7.1 g). Then, the dichloromethane was distilled off under reduced pressure, and the compound B-1 (3.0 g) was obtained by drying under reduced pressure.

The results of analyzing the obtained compound by NMR are shown below.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.76-7.82 (m, 10H, ArH), 7.59 (s, 2H, ArH), 4.55 (s, 2H _{, CH 2), 2.29 (m} , 6H, CH 3), 1.90-2.08 (m, 2H, cyclopentyl), 1.48-1.75 (m, 9H, OCCH 3 + cyclopentyl).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 77.3, −111.5, −118.1, −122.4.
From the results shown above, it was confirmed that the compound B-1 had a structure shown below.

(Synthesis Examples 27 to 48) <Synthesis of Compounds B-2 to B-23>
In the said synthesis example 24, it carried out by the same method except having changed perfluorobutanesulfonic-acid potassium salt into the salt shown to the following Tables 7-12, respectively (equal molar amount), and synthesize | combining.

(Synthesis Example 49) <Synthesis of Compound C>
Under a nitrogen atmosphere, Compound 1 (8.81 g) and dichloromethane (88.1 g) were added to a three-necked flask and cooled to 5 ° C. or lower. N, N-dimethylaminopyridine (0.49 g) was added thereto and stirred at 5 ° C. or lower for 5 minutes, and then ethyl-N, N-dimethylaminopropylcarbodiimide (9.59 g) was added. After stirring for 10 minutes, a dichloromethane solution (30 g) of 1-ethylcyclohexanol (5.13 g) was slowly added dropwise. After completion of the addition, the mixture was warmed to room temperature, stirred at room temperature for 31 hours, washed with dilute hydrochloric acid, Washing with pure water was repeated. The organic phase was dropped into n-hexane (100 g) and reprecipitated to obtain Compound C (2.0 g).

The results of analyzing the obtained compound by NMR are shown below.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.80-7.92 (m, 10H, ArH), 7.67 (s, 2H, ArH), 4.66 (s, 2H _{, CH 2), 2.37 (s} , 6H, Ar-CH 3), 2.13-2.16 (m, 2H, cyclohexyl), 1.93 (q, 2H, CH 2 CH 3), 1. 14-1.57 (m, 8H, cyclohexyl) , 0.84 (t, 3H, CH 2 CH 3).
From the results described above, it was confirmed that the compound C had a structure shown below.

(Synthesis Example 50) <Synthesis of Compound C-1>
Compound C (4.1 g), dichloromethane (57 g) and pure water (56.9 g) were mixed, potassium perfluorobutanesulfonate (2.8 g) was added thereto, and the mixture was stirred overnight at room temperature. Thereafter, the organic phase was separated, and the organic phase was washed 4 times with pure water (56.9 g). Then, dichloromethane was distilled off under reduced pressure and 5.3 g of compound C-1 was obtained by drying under reduced pressure.

The results of analyzing the obtained compound by NMR are shown below.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.80-7.92 (m, 10H, ArH), 7.67 (s, 2H, ArH), 4.66 (s, 2H _{, CH 2), 2.37 (s} , 6H, Ar-CH 3), 2.13-2.16 (m, 2H, cyclohexyl), 1.93 (q, 2H, CH 2 CH 3), 1. 14-1.57 (m, 8H, cyclohexyl), 0.84 (t, 3H, CH2CH3).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 77.3, −111.5, −118.1, −122.4.
From the results shown above, it was confirmed that the compound C-1 had a structure shown below.

(Synthesis Examples 51-72) <Synthesis of Compounds C-2 to C-23>
In the said synthesis example 50, it carried out by the same method except having changed perfluorobutanesulfonic-acid potassium salt into the salt shown to the following Tables 13-19, respectively (equal molar amount), and synthesize | combining.

<Preparation of resist composition>
(Examples 1 to 12, Comparative Example 1)
Each component shown in Table 20 was mixed and dissolved to prepare a positive resist composition.

In Table 20, each abbreviation indicates the following, and the numerical value in [] is the blending amount (part by mass).
(A) -1: a copolymer represented by the following chemical formula (A1-11-1), Mw7000, Mw / Mn = 1.5. In the formula, a1 / a2 / a3 / a4 = 40/25/25/10, and the ratio (mol%) of each structural unit is shown. This copolymer is obtained by polymerizing α-methacryloyloxy-γ butyrolactone, 1-ethyl-1-cyclohexyl methacrylate, 1-methyl-1-cyclopentyl methacrylate, and 3-hydroxy-1-adamantyl methacrylate by known radical polymerization. It is a thing.

(B) -1: a compound represented by the following chemical formula (B) -1.
(B) -2: Compound (compound A-22) represented by the following chemical formula (B) -2.
(B) -3: a compound represented by the following chemical formula (B) -3 (compound B-22).
(B) -4: Compound represented by the following chemical formula (B) -4 (compound C-22).
(B) -5: Compound (compound A-20) represented by the following chemical formula (B) -5.
(B) -6: A compound represented by the following chemical formula (B) -6 (compound B-20).
(B) -7: Compound (compound C-20) represented by the following chemical formula (B) -7.
(B) -8: A compound represented by the following chemical formula (B) -8 (compound A-18).
(B) -9: A compound represented by the following chemical formula (B) -9 (compound B-18).
(B) -10: Compound (compound C-18) represented by the following chemical formula (B) -10.
(B) -11: a compound represented by the following chemical formula (B) -11 (compound A-23).
(B) -12: A compound represented by the following chemical formula (B) -12 (compound B-23).
(B) -13: Compound represented by the following chemical formula (B) -13 (compound C-23).

(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(S) -1: γ-butyrolactone.
(S) -2: Mixed solvent of PGMEA / PGME = 6/4 (mass ratio).

<Evaluation of lithography properties>
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 an 8-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 thickness of 77 nm was formed. Each of the positive resist compositions prepared above is applied onto the antireflection film using a spinner, prebaked (PAB) on a hot plate at 90 ° C. for 60 seconds, and dried. Thus, a resist film having a thickness of 150 nm was formed.
Next, an ArF immersion exposure apparatus NSR-S302B (manufactured by Nikon; NA (numerical aperture) = 0.60, σ 2/3 Annu)) is applied to the resist film through a 6% halftone mask pattern. , ArF excimer laser (193 nm) was selectively irradiated.
Thereafter, PEB treatment is performed at 90 ° C. for 60 seconds, followed by development with a 2.38 mass% TMAH aqueous solution NMD-3 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C. for 30 seconds, and then pure water is added for 30 seconds. The sample was rinsed with water, shaken and dried, and post-baked at 100 ° C. for 60 seconds.
As a result, in each example, a line and space pattern (hereinafter referred to as “L / S pattern”) having a line width of 130 nm and a pitch of 260 nm was formed on the resist film.
The sensitivity at which the 130 nm L / S pattern was formed was determined as the optimum exposure dose Eop (mJ / cm ² ). Table 21 shows the Eop of each positive resist composition.

<Evaluation of PEB Sensitivity>
Using the obtained positive resist composition solution, PEB Sensitivity (hereinafter referred to as “PEBs”) was evaluated by the following procedure. The PEB temperature conditions at that time were 88 ° C., 90 ° C., and 92 ° C. The procedure is shown below.
At the three PEB temperatures (88 ° C., 90 ° C., and 92 ° C.), calibration curves are created for the relationship of the pattern size (actually measured value) to the exposure amount. Next, EOP when a line and space pattern having a line width of 130 nm and a pitch of 260 nm is formed at a PEB temperature of 90 ° C. is calculated from a calibration curve at a PEB temperature of 90 ° C. (calculated value). The calculated value of the pattern size is calculated by substituting the calculated value of EOP into a calibration curve at a PEB temperature of 88 ° C., a calibration curve at a PEB temperature of 90 ° C., and a calibration curve at a PEB temperature of 92 ° C.
Next, plot the calculated values of the three pattern sizes on the vertical axis, create a calibration curve plotting the temperature (88 ° C, 90 ° C, 92 ° C) on the horizontal axis, and change the slope of the calibration curve to the PEB temperature change. The amount of change in pattern size per unit temperature (nm / ° C.). The results are shown in Table 21.

[LWR (line width roughness) evaluation]
In the L / S pattern having a line width of 130 nm and a pitch of 260 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 21. 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.

[MEF (mask error factor) evaluation]
In the above Eop, an S / L pattern is formed using a mask pattern that targets an S / L pattern having a space width of 120 nm and a pitch of 240 nm and a mask pattern that targets an S / L pattern having a space width of 130 nm and a pitch of 260 nm. And the value of MEF was calculated | required from the following formula | equation. The results are also shown in Table 21.
MEF = | CD130-CD120 | / | MD130-MD120 |
In the above formula, CD130 and CD120 are the actual space widths (nm) of the S / L patterns formed using the mask patterns targeting the space widths 130 nm and 120 nm, respectively. MD130 and MD120 are space widths (nm) targeted by the mask pattern, respectively, and MD130 = 130 and MD120 = 120. The closer this MEF value is to 1, the more the resist pattern faithful to the mask pattern is formed.

  From the above results, it is confirmed that the resist compositions of Examples 1 to 12 according to the present invention are all superior to PEB Sensitivity and LWR than the resist composition of Comparative Example 1, and that MEF is equivalent or better. It was.

Claims (9)

A resist composition containing a base 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 said acid generator component (B) contains the acid generator (B1) which consists of a compound represented by the following general formula (b1-14), The resist composition characterized by the above-mentioned.

[Wherein, R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group; any two of R ⁷ ″ to R ⁹ ″ are bonded to each other to form a sulfur atom in the formula A ring may be formed; at least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group in which a part of hydrogen atoms is substituted with a group represented by the following general formula (b14-2) ; X ^- is an anion. ]

[Wherein, R ⁵⁰ is a linear or branched alkylene group, R ⁵¹ is an alkyl group having 1 to 6 carbon atoms, and R ⁵² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. , N is 0 or an integer of 1-6. —CH ₂ — constituting the monocyclic structure may be substituted with an oxygen atom (—O—). ]   The resist composition according to claim 1, wherein the base component (A) is a base component whose solubility in an alkali developer is increased by the action of an acid.   The resist composition according to claim 2, wherein the substrate component (A) is a resin component (A1) and has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.   The resist composition according to claim 1, wherein the base material component (A) further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.   The resist composition according to claim 1, wherein the base material component (A) further includes 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 a support using the resist composition according to any one of claims 1 to 6, a step of exposing the resist film, and an alkali development of the resist film to form a resist pattern A resist pattern forming method including a forming step. The compound represented by the following general formula (b1-14).

[Wherein, R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group; any two of R ⁷ ″ to R ⁹ ″ are bonded to each other to form a sulfur atom in the formula A ring may be formed; at least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group in which a part of hydrogen atoms is substituted with a group represented by the following general formula (b14-2) ; X ^- is an anion. ]

[Wherein, R ⁵⁰ is a linear or branched alkylene group, R ⁵¹ is an alkyl group having 1 to 6 carbon atoms, and R ⁵² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. , N is 0 or an integer of 1-6. —CH ₂ — constituting the monocyclic structure may be substituted with an oxygen atom (—O—). ]
A compound represented by   An acid generator comprising the compound according to claim 8.