JP7129167B2 - RESIST COMPOSITION AND RESIST PATTERN MANUFACTURING METHOD - Google Patents

Description

The present invention relates to a salt, an acid generator, a resist composition, and a method for producing a resist pattern.

Patent Document 1 describes a resist composition containing salts represented by the following formulas as acid generators.

JP 2014-235248 A

In some cases, the line edge roughness (LER) of the resist composition using each of the above salts as an acid generator is not always satisfactory.

［式（Ｉ）中、
Ａｒは、置換基を有していてもよい炭素数６～１８の芳香族炭化水素基を表す。
Ｘは、硫黄原子又はヨウ素原子を表す。Ｘが硫黄原子の時、ｎは２であり、Ｘがヨウ素原子の時、ｎは１である。
Ｒ^１は、置換基を有していてもよい炭素数１～１８の炭化水素基を表し、Ｘが硫黄原子の時、２つのＲ^１が一緒になって環を形成してもよいし、Ｒ^１とＡｒとが一緒になって環を形成してもよい。Ｘが硫黄原子の時、２つのＲ^１は、同じでも異なっていてもよい。
Ａ^－は、有機アニオンを表す。］
〔２〕Ａｒが、置換基を有してもよいフェニレン基である〔１〕に記載の塩。
〔３〕Ｒ^１が、置換基を有していてもよいフェニル基である〔１〕又は〔２〕に記載の塩。
〔４〕Ａ^－が、スルホン酸アニオン、スルホニルイミドアニオン、スルホニルメチドアニオン又はカルボン酸アニオンである〔１〕～〔３〕のいずれかに記載の塩。
〔５〕〔１〕～〔４〕のいずれかに記載の塩を含有する酸発生剤。
〔６〕〔５〕に記載の酸発生剤と酸不安定基を有する樹脂とを含有するレジスト組成物。
〔７〕さらに、前記酸発生剤から発生する酸よりも酸性度の低い酸を発生する塩を含有する〔６〕に記載のレジスト組成物。
〔８〕（１）〔６〕又は〔７〕に記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層を露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程、
を含むレジストパターンの製造方法。 The present invention provides the following inventions.
[1] A salt represented by the formula (I).

[in the formula (I),
Ar represents an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent.
X represents a sulfur atom or an iodine atom. When X is a sulfur atom, n is 2, and when X is an iodine atom, n is 1.
R ¹ represents an optionally substituted hydrocarbon group having 1 to 18 carbon atoms, and when X is a sulfur atom, two R ¹ may combine to form a ring, R ¹ and Ar may together form a ring. When X is a sulfur atom, two R ¹ may be the same or different.
A ⁻ represents an organic anion. ]
[2] The salt of [1], wherein Ar is a phenylene group optionally having a substituent.
[3] The salt of [1] or [2], wherein R ¹ is an optionally substituted phenyl group.
[4] The salt according to any one of [1] to [3] ^, wherein A- is a sulfonate anion, a sulfonylimide anion, a sulfonylmethide anion or a carboxylate anion.
[5] An acid generator containing the salt according to any one of [1] to [4].
[6] A resist composition containing the acid generator described in [5] and a resin having an acid-labile group.
[7] The resist composition of [6], further comprising a salt that generates an acid with a lower acidity than the acid generated from the acid generator.
[8] (1) a step of applying the resist composition according to [6] or [7] onto a substrate;
(2) a step of drying the applied composition to form a composition layer;
(3) exposing the composition layer;
(4) heating the composition layer after exposure; and (5) developing the composition layer after heating;
A method of manufacturing a resist pattern comprising:

By using a resist composition containing the salt of the present invention as an acid generator, a resist pattern with good line edge roughness (LER) can be produced.

As used herein, "(meth)acrylate" means "at least one of acrylate and methacrylate". Notations such as "(meth)acrylic acid" and "(meth)acryloyl" have the same meaning.
In addition, unless otherwise specified, a group that can be linear, branched and/or cyclic such as an "aliphatic hydrocarbon group" includes any of them. Where stereoisomers exist, all stereoisomers are included.
As used herein, "the solid content of the resist composition" means the total amount of components excluding the solvent (E) described below from the total amount of the resist composition.

［式（Ｉ）中、
Ａｒは、置換基を有してもよい炭素数６～１８の２価の芳香族炭化水素基を表す。
Ｘは、硫黄原子又はヨウ素原子を表す。Ｘが硫黄原子の時、ｎは２であり、Ｘがヨウ素原子の時、ｎは１である。
Ｒ^１は、置換基を有していてもよい炭素数１～１８の炭化水素基を表し、Ｘが硫黄原子の時、２つのＲ^１又はＲ^１とＡｒとが一緒になって環を形成してもよい。Ｘが硫黄原子の時、２つのＲ^１は、同じでも異なっていてもよい。
Ａ^－は、有機アニオンを表す。］ [Salt Represented by Formula (I)]
The salt of the present invention is an iodine-containing salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)").

[in the formula (I),
Ar represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent.
X represents a sulfur atom or an iodine atom. When X is a sulfur atom, n is 2, and when X is an iodine atom, n is 1.
R ¹ represents an optionally substituted hydrocarbon group having 1 to 18 carbon atoms, and when X is a sulfur atom, two R ¹ or R ¹ and Ar together form a ring You may When X is a sulfur atom, two R ¹ may be the same or different.
A ⁻ represents an organic anion. ]

炭素数２～２４のアルコキシアルキル基としては、メトキシメチル基、メトキシエチル基、エトキシエチル基、エトキシメチル基等が挙げられる。
炭素数２～２４のアルコキシアルコキシ基としては、メトキシメトキシ基、メトキシエトキシ基、エトキシメトキシ基、エトキシエトキシ基等が挙げられる。
炭素数１～１２のヒドロキシアルキル基としては、ヒドロキシメチル基、ヒドロキシエチル基等が挙げられる。
Ａｒで表される置換基を有していてもよい炭素数６～１８の２価の芳香族炭化水素基は、置換基を有してもよいフェニレン基が好ましく、無置換のフェニレン基がより好ましい。 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by Ar include aryl groups such as a phenylene group, a naphthylene group, an anthrylene group, a tolylene group, a xylylene group, and a bilenylene group. preferable.
Examples of substituents that the aromatic hydrocarbon group of Ar may have include a hydroxy group, a nitro group, a cyano group, a halogen atom, an alkoxy group having 1 to 12 carbon atoms, and an alicyclic carbon having 3 to 12 carbon atoms. A hydrogen group, a carboxyl group, an alkoxyalkyl group having 2 to 24 carbon atoms, an alkoxyalkoxy group having 2 to 24 carbon atoms, a hydroxyalkyl group having 1 to 12 carbon atoms, or a combination thereof. Among them, a hydroxy group, a nitro group, a cyano group, a halogen atom or an alkoxy group having 1 to 12 carbon atoms is preferable.
Halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
Examples of alkoxy groups having 1 to 12 carbon atoms include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, and undecyloxy. group, dodecyloxy group, and the like.
Examples of the alicyclic hydrocarbon group having 3 to 12 carbon atoms include groups shown below. * is a bond with a ring.

The alkoxyalkyl group having 2 to 24 carbon atoms includes methoxymethyl group, methoxyethyl group, ethoxyethyl group, ethoxymethyl group and the like.
The alkoxyalkoxy group having 2 to 24 carbon atoms includes methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group and the like.
A hydroxyalkyl group having 1 to 12 carbon atoms includes a hydroxymethyl group, a hydroxyethyl group, and the like.
The divalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent represented by Ar is preferably a phenylene group which may have a substituent, more preferably an unsubstituted phenylene group. preferable.

The hydrocarbon group having 1 to 18 carbon atoms represented by R ¹ includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a combination thereof.
The aliphatic hydrocarbon group includes alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group and nonyl group. The number of carbon atoms in the aliphatic hydrocarbon group is preferably 1-9, more preferably 3-8.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and may be saturated or unsaturated. The alicyclic hydrocarbon group includes monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclononyl, cyclodecyl, and cyclododecyl, norbornyl, and adamantyl. a cyclopentylcyclopentyl group, a cyclopentylcyclohexyl group, a cyclopentylnorbornyl group, a cyclopentyladamantyl group, a cyclohexylcyclopentyl group, a cyclohexylcyclohexyl group, a cyclohexylnorbornyl group, a cyclohexyladamantyl group, a norbornylcyclopentyl group, a norbornylcyclohexyl group, Polycyclic cycloalkyl groups such as norbornylnorbornyl group, norbornyladamantyl group, adamantylcyclopentyl group, adamantylcyclohexyl group, adamantylcyclohexyl group and adamantylnorbornyl group are included. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3-12, more preferably 3-10.
Aromatic hydrocarbon groups include phenyl group, 1-naphthyl group, 2-naphthyl group, anthnyl group, biphenyl group, anthryl group, phenanthryl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-tert-butylphenyl group, 4-hexylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, Aryl groups such as 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl group are included. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6-14, more preferably 6-10.
Examples of groups in which the above hydrocarbon groups are combined include alkyl-cycloalkyl groups (methyladamantyl group, ethyladamantyl group, methylcyclohexyl group, methylcyclopentyl group), cycloalkyl-alkyl groups (adamantylmethyl group, adamantylethyl group, cyclohexyl methyl group, cyclopentylmethyl group), cycloalkyl-aryl group (4-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aralkyl group (e.g., phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1 -Phenyl-1-propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1- pentyl group, 6-phenyl-1-hexyl group, etc.).

Substituents which the hydrocarbon group represented by R ¹ may have include a hydroxy group, a nitro group, a cyano group, a halogen atom, an alkoxy group having 1 to 12 carbon atoms, a carboxyl group, and a 2 to 24 carbon atoms. alkoxyalkyl groups, alkoxyalkoxy groups having 2 to 24 carbon atoms, hydroxyalkyl groups having 1 to 12 carbon atoms, or groups in which these are combined. Among them, a hydroxy group, a nitro group, a cyano group, a halogen atom or an alkoxy group having 1 to 12 carbon atoms is preferable. Specific examples of these substituents are the same as those exemplified as the substituents of Ar.
The optionally substituted C 1-18 hydrocarbon group represented by R ¹ is preferably an optionally substituted phenyl group or a C 1-4 alkyl group, and substituted A phenyl group which may have a group is preferred.

X is preferably a sulfur atom.

Examples of the structure in which two R ^1s together form a ring or the structure in which R ¹ and Ar together form a ring include the following structures.

Specific examples of cations constituting salt (I) include cations represented by the following formulas (Ic-1) to (Ic-12).

Among the above cations, formula (Ic-1), formula (Ic-2), formula (Ic-3), formula (Ic-9) and formula (Ic-10) The cations represented are preferred.

［式（Ｉ－Ａ）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
Ｌ^ｂ１は、炭素数１～２４の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ_２－は－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子はフッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよいメチル基又は置換基を有していてもよい炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。］ Organic anions (A ⁻ ) include sulfonate anions, sulfonylimide anions, sulfonylmethide anions and carboxylate anions. Among these, sulfonate anions are preferred, and sulfonate anions represented by formula (IA) are more preferred.

[In the formula (IA),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O— or —CO—, and the saturated hydrocarbon A hydrogen atom contained in the hydrogen group may be substituted with a fluorine atom or a hydroxy group.
Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -SO ₂ - or -CO-. ]

The perfluoroalkyl groups for Q ¹ and Q ² include trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluorosec-butyl, perfluorotert-butyl, perfluoropentyl and perfluoro A hexyl group and the like can be mentioned.
Q ¹ and Q ² are each independently preferably a fluorine atom or a trifluoromethyl group, and more preferably both a fluorine atom.

The divalent saturated hydrocarbon group for L ^b1 includes a linear or branched alkanediyl group and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. A group formed by combining two or more kinds may also be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 ,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group , tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group. alkanediyl group;
ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group;
monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbons such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group and the like.

［式（ｂ１－１）中、
Ｌ^ｂ２は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ３は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
ただし、Ｌ^ｂ２とＬ^ｂ３との合計炭素数は、２２以下である。
式（ｂ１－２）中、
Ｌ^ｂ４は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ５は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
ただし、Ｌ^ｂ４とＬ^ｂ５との合計炭素数は、２２以下である。
式（ｂ１－３）中、
Ｌ^ｂ６は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
Ｌ^ｂ７は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
ただし、Ｌ^ｂ６とＬ^ｂ７との合計炭素数は、２３以下である。］ The group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced with —O— or —CO— is, for example, any one of formulas (b1-1) to (b1-3). The group represented by is mentioned. In formulas (b1-1) to (b1-3) and specific examples of formulas (b1-4) to (b1-11), * represents a bond with -Y.

[In formula (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO—.
However, the total carbon number of L ^b2 and L ^b3 is 22 or less.
In formula (b1-2),
L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO—.
However, the total carbon number of L ^b4 and L ^b5 is 22 or less.
In formula (b1-3),
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO—.
However, the total carbon number of L ^b6 and L ^b7 is 23 or less. ]

In formulas (b1-1) to (b1-3), when —CH ₂ — contained in the saturated hydrocarbon group is replaced with —O— or —CO—, the number of carbon atoms before replacement is the number of saturated hydrocarbon The number of carbon atoms in the group.
As the divalent saturated hydrocarbon group and the group in which —CH ₂ — contained in the saturated hydrocarbon group and the hydrogen atom may be substituted as described above, the divalent saturated hydrocarbon group L ^b1 and similar ones.

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group; —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—.
The group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced with —O— or —CO— is a group represented by formula (b1-1) or formula (b1-3) is preferred.

［式（ｂ１－４）中、
Ｌ^ｂ８は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
式（ｂ１－５）中、
Ｌ^ｂ９は、炭素数１～２０の２価の飽和炭化水素基を表す。
Ｌ^ｂ１０は、単結合又は炭素数１～１９の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ９及びＬ^ｂ１０の合計炭素数は２０以下である。
式（ｂ１－６）中、
Ｌ^ｂ１１は、炭素数１～２１の２価の飽和炭化水素基を表す。
Ｌ^ｂ１２は、単結合又は炭素数１～２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１１及びＬ^ｂ１２の合計炭素数は２１以下である。
式（ｂ１－７）中、
Ｌ^ｂ１３は、炭素数１～１９の２価の飽和炭化水素基を表す。
Ｌ^ｂ１４は、単結合又は炭素数１～１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１５は、単結合又は炭素数１～１８の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１３～Ｌ^ｂ１５の合計炭素数は１９以下である。
式（ｂ１－８）中、
Ｌ^ｂ１６は、炭素数１～１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１７は、炭素数１～１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１８は、単結合又は炭素数１～１７の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１６～Ｌ^ｂ１８の合計炭素数は１９以下である。］ Examples of formula (b1-1) include groups represented by any one of formulas (b1-4) to (b1-8).

[In formula (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
In formula (b1-5),
L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b9 and L ^b10 is 20 or less.
In formula (b1-6),
L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b11 and L ^b12 is 21 or less.
In formula (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b13 to L ^b15 is 19 or less.
In formula (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b16 to L ^b18 is 19 or less. ]

L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b10 is preferably a single bond or a C 1-19 divalent saturated hydrocarbon group, more preferably a single bond or a C 1-8 divalent saturated hydrocarbon group.
L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a C 1-18 divalent saturated hydrocarbon group, more preferably a single bond or a C 1-8 divalent saturated hydrocarbon group.
L ^b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b18 is preferably a single bond or a C 1-17 divalent saturated hydrocarbon group, more preferably a single bond or a C 1-4 divalent saturated hydrocarbon group.

［式（ｂ１－９）中、
Ｌ^ｂ１９は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２０は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子はフッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１９及びＬ^ｂ２０の合計炭素数は２３以下である。
式（ｂ１－１０）中、
Ｌ^ｂ２１は、単結合又は炭素数１～２１の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２２は、単結合又は炭素数１～２１の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子はフッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
Ｌ^ｂ２３は、単結合又は炭素数１～２１の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ２１～Ｌ^ｂ２３の合計炭素数は２１以下である。
式（ｂ１－１１）中、
Ｌ^ｂ２４は、単結合又は炭素数１～２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２５は、炭素数１～２１の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子はフッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
Ｌ^ｂ２６は、単結合又は炭素数１～２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ２４～Ｌ^ｂ２６の合計炭素数は２１以下である。］ Examples of formula (b1-3) include groups represented by any one of formulas (b1-9) to (b1-11).

[In formula (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, a hydrogen atom contained in the divalent saturated hydrocarbon group being substituted with a fluorine atom, a hydroxy group or an acyloxy group; good too. —CH ₂ — contained in the acyloxy group may be replaced with —O— or —CO—, and a hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b19 and L ^b20 is 23 or less.
In formula (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group; good too. —CH ₂ — contained in the acyloxy group may be replaced with —O— or —CO—, and a hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. may —CH ₂ — contained in the acyloxy group may be replaced with —O— or —CO—, and a hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b21 to L ^b23 is 21 or less.
In formula (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group or an acyloxy group. —CH ₂ — contained in the acyloxy group may be replaced with —O— or —CO—, and a hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. may —CH ₂ — contained in the acyloxy group may be replaced with —O— or —CO—, and a hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b24 to L ^b26 is 21 or less. ]

Acyloxy groups include acetyloxy, propionyloxy, butyryloxy, cyclohexylcarbonyloxy, and adamantylcarbonyloxy groups.

Examples of the group represented by formula (b1-4) include the following.

Examples of the group represented by formula (b1-5) include the following.

Examples of the group represented by formula (b1-6) include the following.

Examples of the group represented by formula (b1-7) include the following.

Examples of the group represented by formula (b1-8) include the following.

Examples of the group represented by formula (b1-2) include the following.

Examples of the group represented by formula (b1-9) include the following.

Examples of the group represented by formula (b1-10) include the following.

Examples of the group represented by formula (b1-11) include the following.

The alicyclic hydrocarbon group represented by Y in formula (IA) includes groups represented by formulas (Y1) to (Y11) and formulas (Y36) to (Y40).
When —CH ₂ — contained in the alicyclic hydrocarbon group represented by Y is replaced with —O—, —SO ₂ — or —CO—, the number thereof may be one, or two or more. . Such groups include groups represented by formulas (Y12) to (Y35), formula (Y39), and formula (Y40).

Among them, preferably a group represented by any one of formulas (Y1) to (Y20), formula (Y30), formula (Y31), formula (Y39) or formula (Y40), more preferably formula ( Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y30), formula (Y31), formula (Y39) or a group represented by formula (Y40), more preferably a group represented by formula ( Y11), a group represented by formula (Y15), formula (Y30), formula (Y39) or formula (Y40).
When Y constitutes a spiro ring of formulas (Y28) to (Y33), formula (Y39), formula (Y40), etc., the alkanediyl group between two oxygen atoms has one or more fluorine atoms. is preferred. Among the alkanediyl groups contained in the ketal structure, those in which the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom are preferred.

Substituents for the methyl group represented by Y in formula (IA) include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, and an aromatic hydrocarbon group having 6 to 18 carbon atoms. group, glycidyloxy group or —(CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms or represents an aromatic hydrocarbon group having 6 to 18 carbon atoms, ja represents an integer of 0 to 4, an alkyl group having 1 to 16 carbon atoms, and an alicyclic hydrocarbon group having 3 to 16 carbon atoms; —CH ₂ — contained in may be replaced with —O—, —S(O) ₂ — or —CO—.) and the like.
Substituents for the alicyclic hydrocarbon group represented by Y in formula (IA) include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms optionally substituted by a hydroxy group, a carbon Alicyclic hydrocarbon groups of 3 to 16 carbon atoms, alkoxy groups of 1 to 12 carbon atoms, aromatic hydrocarbon groups of 6 to 18 carbon atoms, aralkyl groups of 7 to 21 carbon atoms, acyl groups of 2 to 4 carbon atoms , a glycidyloxy group or a —(CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, a fluorine atom or a represents an alicyclic hydrocarbon group of 16 or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and —CH ₂ — contained in the alicyclic hydrocarbon group is —O—, —SO ₂ — or —CO may be replaced with -, ja represents an integer of 0 to 4), and the like.

Halogen atoms include fluorine, chlorine, bromine and iodine atoms.
Examples of alicyclic hydrocarbon groups include cyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, cycloheptyl, cyclooctyl, norbornyl, and adamantyl groups.
Examples of aromatic hydrocarbon groups include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group and mesityl group. , a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, an aryl group such as 2-methyl-6-ethylphenyl, and the like.
Examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, heptyl group, 2 -ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group and the like.
The alkyl group optionally substituted with a hydroxy group includes hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy and dodecyloxy groups.
The aralkyl group includes benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, naphthylethyl group and the like.
Acyl groups include acetyl, propionyl and butyryl groups.

The optionally substituted alicyclic hydrocarbon group having 1 to 18 carbon atoms represented by Y in formula (IA) includes the following groups.

In formula (IA), when Y is a methyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 24 carbon atoms, the —CH ₂ — in the divalent saturated hydrocarbon group is preferably replaced with —O— or —CO—.

Y is preferably an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an optionally substituted adamantyl group or having a substituent -CH ₂ - is a group in which a cyclohexane ring is spiro-connected to an adamantyl group, and the alicyclic hydrocarbon group, adamantyl group, or a group in which a cyclohexane ring is spiro-connected to the adamantyl group is -O-, —SO ₂ — or —CO— may be substituted. Y is more preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, or a group represented below.

As the sulfonate anion represented by formula (IA), formulas (B1-A-1) to formula (B1-A-36) and formulas (IA-37) to formula (IA-55 ) is preferably an anion represented by any of formulas (B1-A-1) to (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula ( B1-A-24) ~ formula (B1-A-33), formula (B1-A-36), formula (IA-37) ~ formula (IA-40), formula (IA-47 ) to Formula (IA-55) are more preferred.

［式（Ｂ１－Ａ－１）～式（Ｂ１－Ａ－３６）及び式（I－Ａ－３７）～式（I－Ａ－５５）中、
Ｒ^ｉ２～Ｒ^ｉ７は、炭素数１～４のアルキル基を表し、好ましくはメチル基又はエチル基である。
Ｒ^ｉ８は、炭素数１～１２の脂肪族炭化水素基を表し、好ましくは炭素数１～４のアルキル基、炭素数５～１２の脂環式炭化水素基又はこれらを組合せることにより形成される基であり、より好ましくはメチル基、エチル基、シクロヘキシル基又はアダマンチル基である。
Ｌ^４４は、単結合又は炭素数１～４のアルカンジイル基である。
Ｑ^１及びＱ^２は、上記と同じ意味を表す。］

[Formula (B1-A-1) ~ Formula (B1-A-36) and Formula (IA-37) ~ Formula (IA-55),
R ⁱ² to R ⁱ⁷ represent an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group.
R ⁱ⁸ represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.
L ⁴⁴ is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Q ¹ and Q ² have the same meanings as above. ]

Examples of the sulfonate anion represented by formula (IA) include anions represented by formulas (B1a-1) to (B1a-34).

Among them, the sulfonate anions are represented by formulas (B1a-1) to (B1a-3), formulas (B1a-7) to (B1a-19), and formulas (B1a-22) to (B1a-34). Anions represented by either are preferred.

Sulfonylimide anions include the following.

Sulfonylmethide anions include the following.

Carboxylate anions include the following.

The salt represented by formula (I) can be obtained by arbitrarily combining the above-described organic cations and organic anions. Specific examples of salt (I) represented by formula (I) are shown in Table 1.

In Table 1, salt (I-1) is the salt shown below.

Salt (I) includes salt (I-1) to salt (I-3), salt (I-16) to salt (I-19), salt (I-22) to salt (I-31), salt ( I-44) ~ Salt (I-47), Salt (I-50) ~ Salt (I-59), Salt (I-72) ~ Salt (I-75), Salt (I-78) ~ Salt (I -84), salt (I-197) to salt (I-199), salt (I-212) to salt (I-215), salt (I-218) to salt (I-227), salt (I- 240) to salt (I-243), and salt (I-246) to salt (I-252).

［式中、全ての符号は、それぞれ上記と同じ意味を表す。］
溶剤としては、クロロホルム、水等が挙げられる。
反応温度は通常１０℃～８０－℃であり、反応時間は通常０．５時間～２４時間である。 <Method for producing salt (I)>
Salt (I) can be produced, for example, by reacting a salt represented by formula (Ia) and a salt represented by formula (Ib) in a solvent.

[In the formula, all symbols have the same meanings as described above. ]
Examples of solvents include chloroform and water.
The reaction temperature is usually 10° C. to 80-° C., and the reaction time is usually 0.5 hours to 24 hours.

Examples of the salt represented by formula (Ib) include salts represented by the following formula.

The salt represented by formula (Ia) can be produced by subjecting the salt represented by formula (Ic) to anion exchange by ion exchange chromatography.

Examples of the salt represented by formula (Ic) include salts represented by the following formula.

[Acid generator]
The acid generator of the present invention contains salt (I). The acid generator of the present invention contains one or more salts (I).
The acid generator of the present invention may contain, in addition to the salt (I), other acid generators known in the resist field (hereinafter sometimes referred to as "acid generator (B)"). .
When the salt (I) and the acid generator (B) are contained as acid generators, the contents of the salt (I) and the acid generator (B) are in a mass ratio of salt (I):acid generator ( B) is 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5.

<Acid Generator (B)>
As the acid generator (B), a known acid generator can be used, and it may be an ionic acid generator or a nonionic acid generator. Preferably, it is an ionic acid generator. Ionic acid generators include ionic acid generators comprising a combination of known cations and known anions. The acid generator (B) may contain two or more.

Examples of the acid generator (B) include organic sulfonic acids, organic sulfonium salts, and the like. agents and the like. Specific examples include those represented by any one of formulas (B1-1) to (B1-48). As the acid generator (B), formulas (B1-1) to (B1-3), formulas (B1-5) to (B1-7), formulas (B1-11) to (B1-14) , Formula (B1-17), Formula (B1-20) ~ Formula (B1-26), Formula (B1-29), Formula (B1-31) ~ Formula (B1-48) is particularly preferred.

[Resist composition]
The resist composition of the present invention contains an acid generator containing salt (I) and a resin (A) having an acid-labile group.
The resist composition of the invention preferably further contains a solvent (E) and/or a quencher (C).
The acid generator may contain acid generator (B) in addition to salt (I), as described above.
When the salt (I) or the salt (I) and the acid generator (B) are used as acid generators in the resist composition, the total content of the salt (I) and the acid generator (B) is the resin ( A) 100 parts by weight, preferably 1.5 to 40 parts by weight, more preferably 3 to 35 parts by weight.

<Resin (A)>
Resin (A) has a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"). The resin (A) preferably further contains structural units other than the structural unit (a1). Structural units other than the structural unit (a1) include structural units having no acid-labile group (hereinafter sometimes referred to as "structural unit (s)"), structural units other than the structural unit (a1) and the structural unit (s). Structural units (for example, structural units (a4) having a halogen atom, structural units (a5) having a non-leaving hydrocarbon group, structural units (II) that are decomposed by exposure to generate an acid, etc.) and other relevant fields and structural units derived from known monomers.

［式（１）中、Ｒ^a1～Ｒ^a3は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～２０の脂環式炭化水素基又はこれらを組み合わせた基を表すか、Ｒ^a1及びＲ^a2は互いに結合してそれらが結合する炭素原子とともに炭素数３～２０の２価の脂環式炭化水素基を形成する。
ｍａ及びｎａは、それぞれ独立して、０又は１を表し、ｍａ及びｎａの少なくとも一方は１を表す。
＊は結合手を表す。］

［式（２）中、Ｒ^a1’及びＲ^a2’は、それぞれ独立に、水素原子又は炭素数１～１２の炭化水素基を表し、Ｒ^a3’は、炭素数１～２０の炭化水素基を表すか、Ｒ^a2’及びＲ^a3’は互いに結合してそれらが結合する炭素原子及びＸとともに炭素数３～２０の２価の複素環基を形成し、該炭化水素基及び該２価の複素環基に含まれる－ＣＨ₂－は、－Ｏ－又は－Ｓ－で置き換わってもよい。
Ｘは、酸素原子又は硫黄原子を表す。
ｎａ’は、０又は１を表す。
＊は結合手を表す。］ <Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid-labile group (hereinafter sometimes referred to as "monomer (a1)").
The acid-labile group contained in the resin (A) is preferably a group represented by formula (1) and/or a group represented by formula (2).

[In formula (1), R ^a1 to R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group combining these; ^a1 and R ^a2 are bonded to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
ma and na each independently represent 0 or 1, and at least one of ma and na represents 1;
* represents a bond. ]

[In formula (2), R ^a1′ and R ^a2′ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^a3′ represents a hydrocarbon group having 1 to 20 carbon atoms. or R ^a2′ and R ^a3′ are bonded to each other to form a divalent heterocyclic group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and the hydrocarbon group and the divalent heterocyclic --CH ₂ -- contained in the ring group may be replaced with --O-- or --S--.
X represents an oxygen atom or a sulfur atom.
na' represents 0 or 1;
* represents a bond. ]

アルキル基と脂環式炭化水素基とを組み合わせた基としては、例えば、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基、シクロヘキシルメチル基、アダマンチルメチル基、アダマンチルジメチル基、ノルボルニルエチル基等が挙げられる。
好ましくは、ｍａは０であり、ｎａは１である。
Ｒ^a1及びＲ^a2が互いに結合して２価の脂環式炭化水素基を形成する場合の－Ｃ（Ｒ^a1）（Ｒ^a2）（Ｒ^a3）としては、下記の基が挙げられる。２価の脂環式炭化水素基は、好ましくは炭素数３～１２である。＊は－Ｏ－との結合手を表す。

Examples of alkyl groups of R ^a1 to R ^a3 include methyl group, ethyl group, propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group and n-octyl group.
The alicyclic hydrocarbon groups of R ^a1 to R ^a3 may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl groups. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bond). The alicyclic hydrocarbon groups of R ^a1 to R ^a3 preferably have 3 to 16 carbon atoms.

Groups in which an alkyl group and an alicyclic hydrocarbon group are combined include, for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl An ethyl group etc. are mentioned.
Preferably, ma is 0 and na is 1.
Examples of —C(R ^a1 )(R ^a2 )(R ^a3 ) when R ^a1 and R ^a2 combine to form a divalent alicyclic hydrocarbon group include the following groups. The divalent alicyclic hydrocarbon group preferably has 3-12 carbon atoms. * represents a bond with -O-.

Ｒ^a1'及びＲ^a2'のうち、少なくとも１つは水素原子であることが好ましい。
ｎａ’は、好ましくは０である。 Examples of the hydrocarbon groups of R ^a1′ to R ^a3′ include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups and groups formed by combining these groups.
Examples of the alkyl group and the alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl and biphenyl groups. group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl group, and the like.
Examples of the combined group include a group obtained by combining the aforementioned alkyl group and an alicyclic hydrocarbon group, an aralkyl group such as a benzyl group, an aryl-cyclohexyl group such as a phenylcyclohexyl group, and the like.
The divalent heterocyclic group that R ^a2′ and R ^a3′ are bonded to each other to form with the carbon atom to which they are bonded and X includes the following groups. * represents a bond.

At least one of R ^a1′ and R ^a2′ is preferably a hydrogen atom.
na' is preferably zero.

The group represented by formula (1) includes a 1,1-dialkylalkoxycarbonyl group (in formula (1), R ^a1 to R ^a3 are alkyl groups, ma = 0, na = 1, preferably tert-butoxycarbonyl group), 2-alkyladamantan-2-yloxycarbonyl group (in formula (1), R ^a1 , R ^a2 and the carbon atom to which they are bonded are an adamantyl group, R ^a3 is an alkyl group, ma = 0, na = 1 ) and 1-(adamantan-1-yl)-1-alkylalkoxycarbonyl group (in formula (1), R ^a1 and R ^a2 are alkyl groups, R ^a3 is an adamantyl group, ma = 0, na = 1), etc. Specific examples include the following groups. * represents a bond.

Specific examples of the group represented by formula (2) include the following groups. * represents a bond.

Monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer having an acid labile group.

Among (meth)acrylic monomers having an acid-labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferred. When the resin (A) having a structural unit derived from the monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

［式（ａ１－０）、式（ａ１－１）及び式（ａ１－２）中、
Ｌ^a01、Ｌ^ａ１及びＬ^ａ２は、それぞれ独立に、－Ｏ－又は^＊－Ｏ－（ＣＨ_２）_ｋ１－ＣＯ－Ｏ－を表し、ｋ１は１～７のいずれかの整数を表し、＊は－ＣＯ－との結合手を表す。
Ｒ^a01、Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a02、Ｒ^a03及びＲ^a04は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組み合わせた基を表す。
Ｒ^ａ６及びＲ^ａ７は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組合せることにより形成される基を表す。
ｍ１は０～１４のいずれかの整数を表す。
ｎ１は０～１０のいずれかの整数を表す。
ｎ１’は０～３のいずれかの整数を表す。］ The structural unit derived from a (meth)acrylic monomer having a group represented by formula (1) is preferably a structural unit represented by formula (a1-0) (hereinafter referred to as structural unit (a1-0) ), a structural unit represented by formula (a1-1) (hereinafter sometimes referred to as structural unit (a1-1)), or a structural unit represented by formula (a1-2) (hereinafter referred to as may be referred to as a structural unit (a1-2)). These may be used alone or in combination of two or more.

[In formula (a1-0), formula (a1-1) and formula (a1-2),
L ^a01 , L ^a1 and L ^a2 each independently represent —O— or ^* —O—(CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, * is represents a bond with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents any integer from 0 to 14;
n1 represents any integer from 0 to 10;
n1' represents an integer of 0 to 3; ]

R ^a01 , R ^a4 and R ^a5 are preferably methyl groups.
L ^a01 , L ^a1 and L ^a2 are preferably an oxygen atom or *—O—(CH ₂ ) _k01 —CO—O— (provided that k01 is preferably any integer of 1 to 4, more preferably is 1.), more preferably an oxygen atom.
R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 as alkyl groups, alicyclic hydrocarbon groups and groups in which these groups are combined are the same as the groups listed for R ^a1 to R ^a3 in formula (1). groups.
The alkyl groups of R ^a02 , R ^a03 and R ^a04 preferably have 1 to 6 carbon atoms, more preferably methyl or ethyl, still more preferably methyl.
The alicyclic hydrocarbon groups of R ^a02 , R ^a03 and R ^a04 preferably have 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms.
It is preferable that the combined group of an alkyl group and an alicyclic hydrocarbon group have a total carbon number of 18 or less.
R ^a02 and R ^a03 are preferably alkyl groups having 1 to 6 carbon atoms, more preferably methyl or ethyl groups.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.
The alkyl group in R ^a6 and R ^a7 preferably has 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group or an isopropyl group, still more preferably an ethyl group or an isopropyl group.
m1 is preferably an integer from 0 to 3, more preferably 0 or 1.
n1 is preferably an integer from 0 to 3, more preferably 0 or 1.
n1' is preferably 0 or 1.

As the structural unit (a1-0), for example, a structural unit represented by any one of formulas (a1-0-1) to (a1-0-12) and a methyl group corresponding to R ^a01 is a hydrogen atom. Substituted structural units are included, and structural units represented by any one of formulas (a1-0-1) to (a1-0-10) are preferred.

Examples of the monomer leading to the structural unit (a1-1) include monomers described in JP-A-2010-204646. Among them, a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) and a structural unit in which a methyl group corresponding to R ^a4 is replaced with a hydrogen atom are preferable, and the structural unit represented by formula (a1 -1-1) to a structural unit represented by any one of formulas (a1-1-4) is more preferred.

As the structural unit (a1-2), a structural unit represented by any one of formulas (a1-2-1) to (a1-2-6) and a methyl group corresponding to R ^a5 are replaced with hydrogen atoms. Structural units may be mentioned, and formulas (a1-2-2), (a1-2-5) and (a1-2-6) are preferred.

When the resin (A) contains the structural unit (a1-0) and/or the structural unit (a1-1) and/or the structural unit (a1-2), the total content of these is the total structure of the resin (A) It is generally 10 to 95 mol %, preferably 15 to 90 mol %, more preferably 20 to 85 mol %, relative to the unit.

［式（ａ１－４）中、
Ｒ^a32は、水素原子、ハロゲン原子、又は、ハロゲン原子を有してもよい炭素数１～６のアルキル基を表す。
Ｒ^a33は、ハロゲン原子、ヒドロキシ基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数２～４のアシル基、炭素数２～４のアシルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
ｌａは０～４のいずれかの整数を表す。ｌａが２以上である場合、複数のＲ^a33は互いに同一であっても異なってもよい。
Ｒ^a34及びＲ^a35はそれぞれ独立に、水素原子又は炭素数１～１２の炭化水素基を表し、Ｒ^a36は、炭素数１～２０の炭化水素基を表すか、Ｒ^a35及びＲ^a36は互いに結合してそれらが結合するＣ－Ｏとともに炭素数２～２０の２価の炭化水素基を形成し、該炭化水素基及び該２価の炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－Ｓ－で置き換わってもよい。］ As the structural unit (a1) having a group represented by group (2), a structural unit represented by formula (a1-4) (hereinafter sometimes referred to as "structural unit (a1-4)") is mentioned.

[In the formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or represents a methacryloyloxy group.
la represents an integer of 0 to 4; When la is 2 or more, a plurality of R ^a33 may be the same or different.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^a35 and R ^a36 are bonded to each other to form a C2-C20 divalent hydrocarbon group together with C-O to which they are bonded, and -CH ₂ - contained in the hydrocarbon group and the divalent hydrocarbon group is -O- Alternatively, -S- may be substituted. ]

Examples of alkyl groups for R ^a32 and R ^a33 include methyl, ethyl, propyl, isopropyl, butyl, pentyl and hexyl groups. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, even more preferably a methyl group.
The halogen atoms of R ^a32 and R ^a33 include fluorine, chlorine and bromine atoms.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1,1, 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3, 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl group, n -perfluorohexyl group and the like.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy and hexyloxy groups. Among them, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is even more preferable.
Acyl groups include acetyl, propionyl and butyryl groups.
The acyloxy group includes acetyloxy group, propionyloxy group, butyryloxy group and the like.
The hydrocarbon groups of R ^a34 , R ^a35 and R ^a36 include alkyl groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups, and the same groups as R ^a1′ and R ^a2′ in formula (2). are mentioned.
R ^a36 includes an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these groups. be done.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
R ^a33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group.
la is preferably 0 or 1, more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably an alkyl group having 1 to 12 carbon atoms or an alicyclic hydrocarbon group, more preferably a methyl group or an ethyl group.
The hydrocarbon group of R ^a36 is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination of these A group to be formed, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and the alicyclic hydrocarbon group in R ^a36 are preferably unsubstituted. The aromatic hydrocarbon group for R ^a36 is preferably an aromatic ring having an aryloxy group with 6 to 10 carbon atoms.

Examples of structural units (a1-4) include structural units derived from monomers described in JP-A-2010-204646. Preferred are structural units represented by formulas (a1-4-1) to (a1-4-8) and structural units in which a hydrogen atom corresponding to R ^a32 is replaced with a methyl group, more preferably , and structural units represented by formulas (a1-4-1) to (a1-4-5).

When the resin (A) has the structural unit (a1-4), the content thereof is preferably 10 to 95 mol%, preferably 15 to 90 mol%, based on the total of all structural units of the resin (A). It is more preferably mol %, and even more preferably 20 to 85 mol %.

式（ａ１－５）中、
Ｒ^a8は、ハロゲン原子を有してもよい炭素数１～６のアルキル基、水素原子又はハロゲン原子を表す。
Ｚ^a1は、単結合又は＊－（ＣＨ₂）_h3－ＣＯ－Ｌ⁵⁴－を表し、ｈ３は１～４のいずれかの整数を表し、＊は、Ｌ⁵¹との結合手を表す。
Ｌ⁵¹、Ｌ⁵²、Ｌ⁵³及びＬ⁵⁴は、それぞれ独立に、－Ｏ－又は－Ｓ－を表す。
ｓ１は、１～３のいずれかの整数を表す。
ｓ１’は、０～３のいずれかの整数を表す。 As the structural unit derived from a (meth)acrylic monomer having a group represented by formula (2), a structural unit represented by formula (a1-5) (hereinafter referred to as "structural unit (a1-5)" There is) is also mentioned.

In formula (a1-5),
R ^a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or *—(CH ₂ ) _h3 —CO—L ⁵⁴ —, h3 represents an integer of 1 to 4, and * represents a bond with L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent -O- or -S-.
s1 represents any integer from 1 to 3;
s1′ represents any integer from 0 to 3;

Halogen atoms include fluorine atoms and chlorine atoms, with fluorine atoms being preferred.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, fluoromethyl group and trifluoromethyl. groups.
In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
Preferably, one of L ⁵² and L ⁵³ is —O— and the other is —S—.
As for s1, 1 is preferable.
s1' is preferably an integer of 0-2.
Z ^a1 is preferably a single bond or *—CH ₂ —CO—O—.

Examples of the monomer leading to the structural unit (a1-5) include monomers described in JP-A-2010-61117. Among them, structural units represented by formulas (a1-5-1) to (a1-5-4) are preferable, and represented by formula (a1-5-1) or formula (a1-5-2) Structural units are more preferred.

When the resin (A) has the structural unit (a1-5), the content thereof is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, based on the total structural units of the resin (A). , 5 to 40 mol % is more preferable.

The structural unit (a1) also includes the following structural units.

When the resin (A) contains the above structural unit, its content is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, and 20 to 85 mol, based on the total structural units of the resin (A). % is more preferred.

<Structural unit (s)>
Structural unit (s) is derived from a monomer having no acid-labile group (hereinafter sometimes referred to as "monomer (s)"). As a monomer leading to the structural unit (s), a monomer having no acid-labile group known in the field of resists can be used.
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and not having an acid labile group is preferred. A structural unit having a hydroxy group and no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and/or a structure having a lactone ring and no acid-labile group When a resin having a unit (hereinafter sometimes referred to as "structural unit (a3)") is used in the resist composition of the present invention, the resolution of the resist pattern and adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group possessed by the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When producing a resist pattern from the resist composition of the present invention, when using a high-energy beam such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) as an exposure light source, the structural unit (a2) , it is preferable to use a structural unit (a2) having a phenolic hydroxy group. When using an ArF excimer laser (193 nm) or the like, the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group, more preferably a structural unit (a2-1). As the structural unit (a2), one type may be contained alone, or two or more types may be contained.

［式（ａ２－Ａ）中、
Ｒ^a50は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１～６のアルキル基を表す。
Ｒ^a51は、ハロゲン原子、ヒドロキシ基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数２～４のアシル基、炭素数２～４のアシルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
Ａ^a50は、単結合又は^＊－Ｘ^a51－（Ａ^a52－Ｘ^a52）_na－を表し、＊は－Ｒ^a50が結合する炭素原子との結合手を表す。
Ａ^a52は、それぞれ独立に、炭素数１～６のアルカンジイル基を表す。
Ｘ^a51及びＸ^a52は、それぞれ独立に、－Ｏ－、－ＣＯ－Ｏ－又は－Ｏ－ＣＯ－を表す。
ｎａは、０又は１を表す。
ｍｂは０～４のいずれかの整数を表す。ｍｂが２以上の整数である場合、複数のＲ^a51は互いに同一であっても異なってもよい。］ Structural units having a phenolic hydroxy group include structural units represented by formula (a2-A) (hereinafter sometimes referred to as “structural unit (a2-A)”).

[In the formula (a2-A),
R ^a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or represents a methacryloyloxy group.
A ^a50 represents a single bond or ^* -X ^a51 -(A ^a52 -X ^a52 ) _na -, and * represents a bond with the carbon atom to which -R ^a50 bonds.
Each A ^a52 independently represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 each independently represent -O-, -CO-O- or -O-CO-.
na represents 0 or 1;
mb represents an integer from 0 to 4; When mb is an integer of 2 or more, multiple R ^a51 may be the same or different. ]

Halogen atoms in R ^a50 include fluorine, chlorine and bromine atoms.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom for R ^a50 include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1 , 1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3 , 3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl and n-perfluorohexyl groups.
R ^a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, even more preferably a hydrogen atom or a methyl group.
Examples of the alkyl group for R ^a51 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group and n-hexyl group.
The alkoxy group for R ^a51 includes methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy and tert-butoxy groups. An alkoxy group having 1 to 4 carbon atoms is preferred, a methoxy group or an ethoxy group is more preferred, and a methoxy group is even more preferred.
Acyl groups for R ^a51 include acetyl, propionyl and butyryl groups.
The acyloxy group for R ^a51 includes an acetyloxy group, a propionyloxy group and a butyryloxy group.
R ^a51 is preferably a methyl group.

^* -X ^a51 -(A ^a52 -X ^a52 ) _na - includes ^* -O-, ^* -CO-O-, ^* -O-CO-, ^* -CO-O-A ^a52 -CO-O-, ^* -O-CO-A ^a52 -O-, ^* -O-A ^a52 -CO-O-, ^* -CO-O-A ^a52 -O-CO-, ^* -O-CO-A ^a52 -O-CO -, and the like. Among them, ^* -CO-O-, ^* -CO-OA ^a52 -CO-O- and ^{* -OA a52} -CO-O- are preferred.

The alkanediyl groups include methylene, ethylene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane- 1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2 -methylbutane-1,4-diyl group and the like.
A ^a52 is preferably a methylene group or an ethylene group.

A ^a50 is preferably a single bond, ^* -CO-O- or ^* -CO-O-A ^a52 -CO-O-, a single bond, ^* -CO-O- or ^* -CO-O-CH ₂ --CO--O-- is more preferred, and a single bond or ^* --CO--O-- is even more preferred.

mb is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.
The hydroxyl group is preferably bonded to the o-position or p-position of the benzene ring, more preferably bonded to the p-position.

Structural units (a2-A) include structural units represented by formulas (a2-2-1) to (a2-2-8). The structural unit (a2-A) includes a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-2), and a structural unit represented by formula (a2-2-5). and a structural unit represented by formula (a2-2-6).

Examples of the monomer that induces the structural unit (a2-A) include monomers described in JP-A-2010-204634 and JP-A-2012-12577.

When the structural unit (a2-A) is contained in the resin (A), the content of the structural unit (a2-A) is preferably 5 to 80 mol% of the total structural units, more preferably It is 10 to 70 mol %, more preferably 15 to 65 mol %.

式（ａ２－１）中、
Ｌ^a3は、－Ｏ－又は^＊－Ｏ－（ＣＨ₂）_k2－ＣＯ－Ｏ－を表し、
ｋ２は１～７のいずれかの整数を表す。＊は－ＣＯ－との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０～１０のいずれかの整数を表す。 Examples of the structural unit (a2) having an alcoholic hydroxy group include structural units represented by formula (a2-1) (hereinafter sometimes referred to as "structural unit (a2-1)").

In formula (a2-1),
L ^a3 represents —O— or ^* —O—(CH ₂ ) _k2 —CO—O—;
k2 represents any integer from 1 to 7; * represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer from 0 to 10;

In formula (a2-1), L ^a3 is preferably —O—, —O—(CH ₂ ) _f1 —CO—O— (f1 is an integer of 1 to 4). , more preferably -O-.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably any integer from 0 to 3, more preferably 0 or 1.

Examples of structural units (a2-1) include structural units derived from monomers described in JP-A-2010-204646. Structural units represented by any one of formulas (a2-1-1) to (a2-1-6) are preferred, and any one of formulas (a2-1-1) to (a2-1-4) Structural units represented by the formula (a2-1-1) or (a2-1-3) are more preferable.

When the resin (A) contains the structural unit (a2-1), its content is usually 1 to 45 mol%, preferably 1 to 40 mol%, based on the total structural units of the resin (A). Yes, more preferably 1 to 35 mol %, still more preferably 2 to 20 mol %, still more preferably 2 to 10 mol %.

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocyclic ring such as a β-propiolactone ring, γ-butyrolactone ring, δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. It's okay. A γ-butyrolactone ring, an adamantanelactone ring, or a bridged ring containing a γ-butyrolactone ring structure is preferred.

［式（ａ３－１）、式（ａ３－２）、式（ａ３－３）及び式（ａ３－４）中、
Ｌ^ａ４、Ｌ^ａ５及びＬ^ａ６は、－Ｏ－又は^＊－Ｏ－（ＣＨ_２）_ｋ３－ＣＯ－Ｏ－（ｋ３は１～７のいずれかの整数を表す。）で表される基を表す。
Ｌ^ａ７は、－Ｏ－、^＊－Ｏ－Ｌ^ａ８－Ｏ－、^＊－Ｏ－Ｌ^ａ８－ＣＯ－Ｏ－、^＊－Ｏ－Ｌ^ａ８－ＣＯ－Ｏ－Ｌ^ａ９－ＣＯ－Ｏ－又は^＊－Ｏ－Ｌ^ａ８－Ｏ－ＣＯ－Ｌ^ａ９－Ｏ－を表す。
Ｌ^ａ８及びＬ^ａ９は、それぞれ独立に、炭素数１～６のアルカンジイル基を表す。
＊はカルボニル基との結合手を表す。
Ｒ^ａ１８、Ｒ^ａ１９及びＲ^ａ２０は、水素原子又はメチル基を表す。
Ｒ^ａ２４は、ハロゲン原子を有してもよい炭素数１～６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^ａ２１は炭素数１～４の脂肪族炭化水素基を表す。
Ｒ^ａ２２、Ｒ^ａ２３及びＲ^ａ２５は、カルボキシ基、シアノ基又は炭素数１～４の脂肪族炭化水素基を表す。
ｐ１は０～５のいずれかの整数を表す。
ｑ１は、０～３のいずれかの整数を表す。
ｒ１は、０～３のいずれかの整数を表す。
ｗ１は、０～８のいずれかの整数を表す。
ｐ１、ｑ１、ｒ１及び／又はｗ１が２以上のとき、複数のＲ^ａ２１、Ｒ^ａ２２、Ｒ^ａ２３及び／又はＲ^ａ２５は互いに同一であってもよく、異なってもよい。］ Structural unit (a3) is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3) or formula (a3-4). One of these may be contained alone, or two or more may be contained.

[In formula (a3-1), formula (a3-2), formula (a3-3) and formula (a3-4),
L ^a4 , L ^a5 and L ^a6 represent a group represented by —O— or ^* —O—(CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7); .
L ^a7 is -O-, ^* -OL ^a8 -O-, ^* -OL ^a8 -CO-O-, ^* -OL ^a8 -CO- ^{OL a9} -CO-O- or ^* -OL ^a8 -O-CO-L ^a9 -O-.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms.
* represents a bond with a carbonyl group.
R ^a18 , R ^a19 and R ^a20 each represent a hydrogen atom or a methyl group.
R ^a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
R ^a22 , R ^a23 and R ^a25 each represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents any integer from 0 to 5;
q1 represents an integer of 0 to 3;
r1 represents an integer of 0 to 3;
w1 represents any integer from 0 to 8;
When p1, q1, r1 and/or w1 are 2 or more, a plurality of R ^a21 , R ^a22 , R ^a23 and/or R ^a25 may be the same or different. ]

The aliphatic hydrocarbon groups represented by R ^a21 , R ^a22 , R ^a23 and R ^a25 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group. An alkyl group is mentioned.
Halogen atoms of R ^a24 include fluorine, chlorine, bromine and iodine atoms.
Examples of the alkyl group for R ^a24 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group and n-hexyl group. , preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group.
The alkyl group having a halogen atom for R ^a24 includes a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluoro A hexyl group, a trichloromethyl group, a tribromomethyl group, a triiodomethyl group and the like can be mentioned.

The alkanediyl groups of L ^a8 and L ^a9 include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5 -diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, 4-diyl group, 2-methylbutane-1,4-diyl group and the like.

In formulas (a3-1) to (a3-3), L ^a4 to L ^a6 are each independently preferably —O— or *—O—(where k3 is an integer of 1 to 4) CH ₂ ) _k3 A group represented by -CO-O-, more preferably -O- and *-O-CH ₂ -CO-O-, more preferably an oxygen atom.
R ^a18 to R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

（式中、Ｒ^ａ２４、Ｌ^ａ７は、上記と同じ意味を表す。） In formula (a3-4), R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, still more preferably a hydrogen atom or a methyl group is.
R ^a25 is preferably a carboxy group, a cyano group or a methyl group.
L ^a7 is preferably -O- or ^* -OL ^a8 -CO-O-, more preferably -O-, -O-CH ₂ -CO-O- or -O-C ₂ H ₄ - It is CO—O—.
In particular, formula (a3-4) is preferably formula (a3-4)'.

(In the formula, R ^a24 and L ^a7 have the same meanings as above.)

As the structural unit (a3), the monomer described in JP-A-2010-204646, the monomer described in JP-A-2000-122294, the structure derived from the monomer described in JP-A-2012-41274 units. As the structural unit (a3), formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3- 1), a structural unit represented by formula (a3-3-2) and any one of formulas (a3-4-1) to (a3-4-12) and R ^a18 , R ^a19 , R ^a20 and R ^a24 A structural unit in which a methyl group corresponding to is replaced with a hydrogen atom is preferred.

When the resin (A) contains the structural unit (a3), the total content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on the total structural units of the resin (A). , more preferably 10 to 60 mol %.
Further, the content of structural unit (a3-1), structural unit (a3-2), structural unit (a3-3) and structural unit (a3-4) is 5 to 60 mol % is preferred, 5 to 50 mol % is more preferred, and 10 to 50 mol % is even more preferred.

［式（ａ４－０）中、
Ｒ⁵は、水素原子又はメチル基を表す。
Ｌ⁴は、単結合又は炭素数１～４の脂肪族飽和炭化水素基を表す。
Ｌ³は、炭素数１～８のペルフルオロアルカンジイル基又は炭素数３～１２のペルフルオロシクロアルカンジイル基を表す。
Ｒ⁶は、水素原子又はフッ素原子を表す。］ <Structural unit (a4)>
The structural unit (a4) is preferably a structural unit containing a fluorine atom.
Structural units (a4) include structural units represented by formula (a4-0).

[In the formula (a4-0),
^R5 represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or a C 1-4 saturated aliphatic hydrocarbon group.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
^R6 represents a hydrogen atom or a fluorine atom. ]

Examples of saturated aliphatic hydrocarbon groups for L ⁴ include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, ethane-1,1- Branched alkanediyl groups such as diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group groups.

The perfluoroalkanediyl group for L ³ includes a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, and a perfluoropropane group. -2,2-diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane -2,2-diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane -1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane -2,2-diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like.
The perfluorocycloalkanediyl group for L ³ includes a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantanediyl group, and the like.

L ⁴ is preferably a single bond, a methylene group or an ethylene group, more preferably a single bond or a methylene group.
L ³ is preferably a C 1-6 perfluoroalkanediyl group, more preferably a C 1-3 perfluoroalkanediyl group.

Examples of the structural unit (a4-0) include structural units shown below and structural units in which a methyl group corresponding to R ⁵ in the following structural units is replaced with a hydrogen atom.

［式（ａ４－１）中、
Ｒ^a41は、水素原子又はメチル基を表す。
Ｒ^a42は、置換基を有していてもよい炭素数１～２０の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
Ａ^a41は、置換基を有していてもよい炭素数１～６のアルカンジイル基又は式（ａ－ｇ１）で表される基を表す。ただし、Ａ^ａ４１及びＲ^ａ４２のうち少なくとも１つは、置換基としてフッ素原子を有する。

〔式（ａ－ｇ１）中、
ｓは０又は１を表す。
Ａ^a42及びＡ^a44は、それぞれ独立に、置換基を有していてもよい炭素数１～５の飽和炭化水素基を表す。
Ａ^a43は、単結合又は置換基を有していてもよい炭素数１～５の飽和炭化水素基を表す。
Ｘ^a41及びＸ^a42は、それぞれ独立に、－Ｏ－、－ＣＯ－、－ＣＯ－Ｏ－又は－Ｏ－ＣＯ－を表す。
ただし、Ａ^a42、Ａ^a43、Ａ^a44、Ｘ^a41及びＸ^a42の炭素数の合計は７以下である。〕
＊は結合手であり、右側の＊が－Ｏ－ＣＯ－Ｒ^a42との結合手である。］ Structural units (a4) include structural units represented by formula (a4-1).

[In formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO— good.
A ^a41 represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by formula (a-g1). However, at least one of A ^a41 and R ^a42 has a fluorine atom as a substituent.

[In formula (a-g1),
s represents 0 or 1;
A ^a42 and A ^a44 each independently represent an optionally substituted saturated hydrocarbon group having 1 to 5 carbon atoms.
A ^a43 represents a single bond or an optionally substituted saturated hydrocarbon group having 1 to 5 carbon atoms.
X ^a41 and X ^a42 each independently represent -O-, -CO-, -CO-O- or -O-CO-.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 7 or less. ]
* is a bond, and * on the right is a bond with —O—CO—R ^a42 . ]

The hydrocarbon group for R ^a42 includes chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these groups.
Chain and cyclic aliphatic hydrocarbon groups may have a carbon-carbon unsaturated bond, but chain and cyclic saturated aliphatic hydrocarbon groups are preferred. The saturated aliphatic hydrocarbon group includes a linear or branched alkyl group, a monocyclic or polycyclic alicyclic hydrocarbon group, and an aliphatic hydrocarbon group formed by combining an alkyl group and an alicyclic hydrocarbon group. group hydrocarbon groups and the like.

芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ビフェニリル基、フェナントリル基及びフルオレニル基が挙げられる。 Chain type aliphatic hydrocarbon groups include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and n-decyl. n-dodecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl and n-octadecyl groups. Cyclic aliphatic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl; decahydronaphthyl, adamantyl, norbornyl and the following groups (* indicates a bond represents a hand.) and other polycyclic alicyclic hydrocarbon groups.

Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, biphenylyl, phenanthryl and fluorenyl groups.

［式（ａ－ｇ３）中、
Ｘ^a43は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^a45は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
＊は結合手を表す。］
ただし、Ｒ^a42－Ｘ^a43－Ａ^a45において、Ｒ^a42がハロゲン原子を有しない場合は、Ａ^a45は、少なくとも１つのハロゲン原子を有する炭素数１～１７の脂肪族炭化水素基を表す。 R ^a42 may have a halogen atom and a group represented by formula (a-g3) as a substituent. A halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a fluorine atom.

[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
* represents a bond. ]
However, in R ^a42 -X ^a43 -A ^a45 , when R ^a42 does not have a halogen atom, A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms and having at least one halogen atom.

Examples of the aliphatic hydrocarbon group for A ^a45 include groups similar to those exemplified for R ^a42 .
R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and/or an aliphatic hydrocarbon group having a group represented by formula (a-g3) preferable.
When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, still more preferably having a carbon number of It is a perfluoroalkyl group having 1 to 6 carbon atoms, particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Perfluoroalkyl groups include perfluoromethyl, perfluoroethyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, perfluorohexyl, perfluoroheptyl and perfluorooctyl groups. A perfluorocyclohexyl group etc. are mentioned as a perfluorocycloalkyl group.
When R ^a42 is an aliphatic hydrocarbon group having a group represented by formula (a-g3), including the number of carbon atoms contained in the group represented by formula (a-g3), the aliphatic hydrocarbon The total number of carbon atoms in the group is preferably 15 or less, more preferably 12 or less. When it has a group represented by formula (a-g3) as a substituent, the number thereof is preferably one.

［式（ａ－ｇ２）中、
Ａ^a46は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
Ｘ^a44は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
ただし、Ａ^a46、Ａ^a47及びＸ^a44の炭素数の合計は１８以下であり、Ａ^a46及びＡ^a47のうち、少なくとも一方は、少なくとも１つのハロゲン原子を有する。
＊はカルボニル基との結合手を表す。］ The aliphatic hydrocarbon having a group represented by formula (a-g3) is more preferably a group represented by formula (a-g2).

[In the formula (a-g2),
A ^a46 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents a carbonyloxy group or an oxycarbonyl group.
A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47 and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* represents a bond with a carbonyl group. ]

The number of carbon atoms in the aliphatic hydrocarbon group of A ^a46 is preferably 1-6, more preferably 1-3.
The number of carbon atoms in the aliphatic hydrocarbon group of A ^a47 is preferably 4 to 15, more preferably 5 to 12, and A ^a47 is more preferably a cyclohexyl group or an adamantyl group.

A more preferred structure of the partial structure represented by *-A ^a46 -X ^a44 -A ^a47 (* is a bond with a carbonyl group) is the following structure.

The alkanediyl group of A ^a41 includes methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group and hexane-1,6-diyl group. straight-chain alkanediyl groups such as; Branched alkanediyl groups such as 2-methylbutane-1,4-diyl group can be mentioned.
Examples of substituents on the alkanediyl group of A ^a41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and still more preferably an ethylene group.

The saturated hydrocarbon groups of A ^a42 , A ^a43 and A ^a44 in the group represented by formula (a-g1) are preferably chain and cyclic saturated hydrocarbon groups and groups formed by combining these. . The saturated hydrocarbon group includes a linear or branched alkanediyl group, a monocyclic alicyclic hydrocarbon group, and a saturated hydrocarbon group formed by combining an alkanediyl group and an alicyclic hydrocarbon group. etc. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group and the like.
Substituents of the saturated hydrocarbon groups of A ^a42 , A ^a43 and A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
s is preferably zero.

Examples of the group represented by the formula (a-g1) in which X ^a42 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group include the following groups. In the following examples, * and ** each represent a bond, and ** is a bond with --O--CO--R ^a42 .

Examples of structural units represented by formula (a4-1) include structural units shown below and structural units in which a methyl group corresponding to R ^a41 in the structural units below is replaced with a hydrogen atom.

［式（ａ４－４）中、
Ｒ^f21は、水素原子又はメチル基を表す。
Ａ^f21は、－（ＣＨ₂）_j1－、－（ＣＨ₂）_j2－Ｏ－（ＣＨ₂）_j3－又は－（ＣＨ₂）_j4－ＣＯ－Ｏ－（ＣＨ₂）_j5－を表す。
ｊ１～ｊ５は、それぞれ独立に、１～６のいずれかの整数を表す。
Ｒ^f22は、フッ素原子を有する炭素数１～１０の炭化水素基を表す。］ Structural units (a4) also include structural units represented by formula (a4-4).

[In the formula (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 represents -(CH ₂ ) _j1 -, -(CH ₂ ) _j2 -O-(CH ₂ ) _j3 - or -(CH ₂ ) _j4 -CO-O-(CH ₂ ) _j5 -.
j1 to j5 each independently represent an integer of 1 to 6;
R ^f22 represents a hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom. ]

The hydrocarbon group for R ^f22 includes aliphatic hydrocarbon groups formed by chain, cyclic and combinations thereof. As the aliphatic hydrocarbon group, an alkyl group and an alicyclic hydrocarbon group are preferred.
The hydrocarbon group having a fluorine atom includes an alkyl group having a fluorine atom, an alicyclic hydrocarbon group having a fluorine atom, and the like.
Specifically, the alkyl group having a fluorine atom includes a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1-(trifluoromethyl)-1,2 , 2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2, 2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis(trifluoro)methyl-2,2,2-trifluoroethyl group, 2-(perfluoropropyl)ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2-(perfluorobutyl)ethyl group, 1,1,2,2,3,3 ,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group and perfluorohexyl and fluorinated alkyl groups such as groups.
The alicyclic hydrocarbon group having a fluorine atom includes fluorinated cycloalkyl groups such as a perfluorocyclohexyl group and a perfluoroadamantyl group.
R ^f22 is preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom. An alkyl group having 1 to 6 carbon atoms and having a fluorine atom is more preferred.

In formula (a4-4), A ^f21 is preferably --(CH ₂ ) _j1 --, more preferably an ethylene group or a methylene group, and still more preferably a methylene group.

Examples of structural units represented by formula (a4-4) include the following structural units and structural units in which a methyl group corresponding to R ^f21 is replaced with a hydrogen atom in structural units represented by the following formulas: be done.

When the resin (A) has the structural unit (a4), the content thereof is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, based on the total structural units of the resin (A), and 3 ~10 mol% is more preferred.

［式（ａ５－１）中、
Ｒ⁵¹は、水素原子又はメチル基を表す。
Ｒ⁵²は、炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる水素原子は炭素数１～８の脂肪族炭化水素基で置換されていてもよい。但し、Ｌ^5５との結合位置にある炭素原子に結合する水素原子は、炭素数１～８の脂肪族炭化水素基で置換されない。
Ｌ^5５は、単結合又は炭素数１～１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］ <Structural unit (a5)>
Examples of non-leaving hydrocarbon groups possessed by the structural unit (a5) include groups having linear, branched or cyclic hydrocarbon groups. Among them, the structural unit (a5) preferably contains an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include structural units represented by formula (a5-1).

[In formula (a5-1),
^R51 represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. . However, the hydrogen atom bonded to the carbon atom at the bonding position with L ⁵⁵ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

The alicyclic hydrocarbon group for R ⁵² may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl groups. Examples of polycyclic alicyclic hydrocarbon groups include adamantyl groups and norbornyl groups.
C1-C8 aliphatic hydrocarbon groups include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Examples include alkyl groups such as octyl and 2-ethylhexyl.
The substituted alicyclic hydrocarbon group includes a 3-methyladamantyl group and the like.
R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

The bivalent saturated hydrocarbon group for L ⁵⁵ includes a bivalent saturated aliphatic hydrocarbon group and a saturated bivalent alicyclic hydrocarbon group, preferably a saturated aliphatic hydrocarbon group. .
Examples of divalent aliphatic saturated hydrocarbon groups include alkanediyl groups such as methylene, ethylene, propanediyl, butanediyl and pentanediyl groups.
The bivalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. The monocyclic alicyclic saturated hydrocarbon group includes cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

式（Ｌ１－１）中、
Ｘ^x1は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ｌ^x1は、炭素数１～１６の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x2は、単結合又は炭素数１～１５の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x1及びＬ^x2の合計炭素数は、１６以下である。
式（Ｌ１－２）中、
Ｌ^x3は、炭素数１～１７の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x4は、単結合又は炭素数１～１６の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x3及びＬ^x4の合計炭素数は、１７以下である。
式（Ｌ１－３）中、
Ｌ^x5は、炭素数１～１５の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x6及びＬ^x7は、それぞれ独立に、単結合又は炭素数１～１４の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x5、Ｌ^x6及びＬ^x7の合計炭素数は、１５以下である。
式（Ｌ１－４）中、
Ｌ^x8及びＬ^x9は、単結合又は炭素数１～１２の２価の脂肪族飽和炭化水素基を表す。
Ｗ^x1は、炭素数３～１５の２価の脂環式飽和炭化水素基を表す。
ただし、Ｌ^x8、Ｌ^x9及びＷ^x1の合計炭素数は、１５以下である。 Examples of the saturated hydrocarbon group in which the methylene group is replaced with an oxygen atom or a carbonyl group include groups represented by formulas (L1-1) to (L1-4). In the following formula, * represents a bond with an oxygen atom.

In formula (L1-1),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total carbon number of L ^x1 and L ^x2 is 16 or less.
In formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x3 and L ^x4 is 17 or less.
In formula (L1-3),
L ^x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent saturated aliphatic hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of L ^x5 , L ^x6 and L ^x7 is 15 or less.
In formula (L1-4),
L ^x8 and L ^x9 each represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent saturated alicyclic hydrocarbon group having 3 to 15 carbon atoms.
However, the total carbon number of L ^x8 , L ^x9 and W ^x1 is 15 or less.

L ^x1 is preferably a C 1-8 divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a C 1-8 divalent aliphatic saturated hydrocarbon group, more preferably a single bond.
L ^x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x5 is preferably a C 1-8 divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a C 1-8 divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene group.
L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x8 is preferably a single bond or a divalent saturated aliphatic hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
L ^x9 is preferably a single bond or a divalent saturated aliphatic hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
W ^x1 is preferably a divalent saturated alicyclic hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

Examples of the group represented by formula (L1-1) include the divalent groups shown below.

Examples of the group represented by formula (L1-2) include the divalent groups shown below.

Examples of the group represented by formula (L1-3) include the divalent groups shown below.

Examples of the group represented by formula (L1-4) include the divalent groups shown below.

L ⁵⁵ is preferably a single bond or a group represented by formula (L1-1).

樹脂（Ａ）が、構造単位（ａ５）を有する場合、その含有率は、樹脂（Ａ）の全構造単位に対して、１～３０モル％が好ましく、２～２０モル％がより好ましく、３～１５モル％がさらに好ましい。 Examples of the structural unit (a5-1) include structural units shown below and structural units in which a methyl group corresponding to R ⁵¹ in the following structural units is replaced with a hydrogen atom.

When the resin (A) has the structural unit (a5), the content thereof is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, based on the total structural units of the resin (A), and 3 ~15 mol% is more preferred.

<Structural unit (a6)>
Structural units (a6) include structural units represented below.

When the resin (A) has the structural unit (a6), the content thereof is preferably 1 to 40 mol%, more preferably 2 to 35 mol%, based on the total structural units of the resin (A), and 3 ~30 mol% is more preferred.

<Structural unit (II)>
The structural unit (II) that decomposes by exposure to generate an acid, specifically includes structural units described in JP-A-2016-79235. or a structural unit having a sulfonio group and an organic anion in a side chain.

［式（ＩＩ－２－Ａ’）中、
Ｘ^ＩＩＩ３は、炭素数１～１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子は、ハロゲン原子、ハロゲン原子を有していてもよい炭素数１～６のアルキル基又はヒドロキシ基で置き換わっていてもよい。
Ａ^ｘ１は、炭素数１～８のアルカンジイル基を表し、該アルカンジイル基に含まれる水素原子は、フッ素原子又は炭素数１～６のペルフルオロアルキル基で置換されていてもよい。
ＲＡ^－は、スルホナート基又はカルボキシレート基を表す。
Ｒ^ＩＩＩ３は、水素原子、ハロゲン原子又はハロゲン原子を有していてもよい炭素数１～６のアルキル基を表す。
Ｚ^ａ＋は、有機カチオンを表す。］ A structural unit having a sulfonate group or a carboxylate group in a side chain is preferably a structural unit represented by formula (II-2-A').

[In the formula (II-2-A '),
X ^III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O—, —S— or —CO— A hydrogen atom contained in the saturated hydrocarbon group may be replaced with a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, or a hydroxy group.
A ^x1 represents an alkanediyl group having 1 to 8 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
RA- represents a sulfonate group ^or a carboxylate group.
R ^III3 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
Z ^a+ represents an organic cation. ]

Halogen atoms represented by R ^III3 include fluorine, chlorine, bromine and iodine atoms.
The alkyl group having 1 to 6 carbon atoms and optionally having a halogen atom represented by R ^III3 includes an alkyl group having 1 to 6 carbon atoms and optionally having a halogen atom represented by R ^a8 . The same can be mentioned.
The alkanediyl group having 1 to 8 carbon atoms represented by A ^x1 includes methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group and pentane-1,5-diyl group. , hexane-1,6-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2, 4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. mentioned.

Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X ^III3 include a linear or branched alkanediyl group and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. and may be a combination of these.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 ,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , dodecane-1,12-diyl group and other linear alkanediyl groups; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group , pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group and other branched alkanediyl groups; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1 ,4-diyl group, cycloalkanediyl group such as cyclooctane-1,5-diyl group; norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane Divalent polycyclic alicyclic saturated hydrocarbon groups such as -2,6-diyl group and the like can be mentioned.

Examples of saturated hydrocarbon groups in which —CH ₂ — is replaced with —O—, —S— or —CO— include divalent groups represented by formulas (X1) to (X53). mentioned. However, -CH ₂ - contained in the saturated hydrocarbon group has 17 or less carbon atoms before being replaced with -O-, -S- or -CO-. In the following formula, * represents a bond with A ^x1 .

X ³ represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms.
X ⁴ represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
X ⁵ represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
X ⁶ represents an alkyl group having 1 to 14 carbon atoms.
X ⁷ represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms.
X ⁸ represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

［式（ｂ２－１）～式（ｂ２－４）において、
Ｒ^ｂ４～Ｒ^ｂ６は、それぞれ独立に、炭素数１～３０の脂肪族炭化水素基、炭素数３～３６の脂環式炭化水素基又は炭素数６～３６の芳香族炭化水素基を表し、該脂肪族炭化水素基に含まれる水素原子は、ヒドロキシ基、炭素数１～１２のアルコキシ基、炭素数３～１２の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基で置換されていてもよく、該脂環式炭化水素基に含まれる水素原子は、ハロゲン原子、炭素数１～１８の脂肪族炭化水素基、炭素数２～４のアルキルカルボニル基又はグリシジルオキシ基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基又は炭素数１～１２のアルコキシ基で置換されていてもよい。
Ｒ^ｂ４とＲ^ｂ５とは、それらが結合する硫黄原子とともに環を形成してもよく、該環に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ（Ｏ）－又は－ＣＯ－に置き換わってもよい。
Ｒ^ｂ７及びＲ^ｂ８は、それぞれ独立に、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
ｍ２及びｎ２は、それぞれ独立に０～５のいずれかの整数を表す。
ｍ２が２以上のとき、複数のＲ^ｂ７は同一であっても異なってもよく、ｎ２が２以上のとき、複数のＲ^ｂ８は同一であっても異なってもよい。
Ｒ^ｂ９及びＲ^ｂ１０は、それぞれ独立に、炭素数１～３６の脂肪族炭化水素基又は炭素数３～３６の脂環式炭化水素基を表す。
Ｒ^ｂ９とＲ^ｂ１０とは、それらが結合する硫黄原子とともに環を形成してもよく、該環に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ（Ｏ）－又は－ＣＯ－に置き換わってもよい。
Ｒ^ｂ１１は、水素原子、炭素数１～３６の脂肪族炭化水素基、炭素数３～３６の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基を表す。
Ｒ^ｂ１２は、炭素数１～１２の脂肪族炭化水素基、炭素数３～１８の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基を表し、該脂肪族炭化水素に含まれる水素原子は、炭素数６～１８の芳香族炭化水素基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、炭素数１～１２のアルコキシ基又は炭素数１～１２のアルキルカルボニルオキシ基で置換されていてもよい。
Ｒ^ｂ１１とＲ^ｂ１２とは、一緒になってそれらが結合する－ＣＨ－ＣＯ－を含む環を形成していてもよく、該環に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ（Ｏ）－又は－ＣＯ－に置き換わってもよい。
Ｒ^ｂ１３～Ｒ^ｂ１８は、それぞれ独立に、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
Ｌ^ｂ３１は、－Ｓ－又は－Ｏ－を表す。
ｏ２、ｐ２、ｓ２、及びｔ２は、それぞれ独立に、０～５のいずれかの整数を表す。
ｑ２及びｒ２は、それぞれ独立に、０～４のいずれかの整数を表す。
ｕ２は、０又は１を表す。
ｏ２が２以上のとき、複数のＲ^ｂ１３は同一であっても異なってもよく、ｐ２が２以上のとき、複数のＲ^ｂ１４は同一であっても異なってもよく、ｑ２が２以上のとき、複数のＲ^ｂ１５は同一であっても異なってもよく、ｒ２が２以上のとき、複数のＲ^ｂ１６は同一であっても異なってもよく、ｓ２が２以上のとき、複数のＲ^ｂ１７は同一であっても異なってもよく、ｔ２が２以上のとき、複数のＲ^ｂ１８は同一であっても異なってもよい。］ Organic cations represented by Z ^a+ include organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, organic benzothiazolium cations and organic phosphonium cations, and organic sulfonium cations and organic iodonium cations. are preferred, and arylsulfonium cations are more preferred.
Specific examples include cations represented by any one of formulas (b2-1) to (b2-4).

[In formulas (b2-1) to (b2-4),
R ^b4 to R ^b6 each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 36 carbon atoms; The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. It may be substituted, and the hydrogen atom contained in the alicyclic hydrocarbon group is a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group. It may be substituted, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring is replaced with —O—, —S(O)— or —CO—. may
R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5;
When m2 is 2 or more, the plurality of R ^b7 may be the same or different, and when n2 is 2 or more, the plurality of R ^b8 may be the same or different.
R ^b9 and R ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring is replaced with —O—, —S(O)— or —CO—. may
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atoms contained in the aromatic hydrocarbon group are alkoxy groups having 1 to 12 carbon atoms or 1 to 1 carbon atoms. It may be substituted with 12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may together form a ring containing —CH—CO— to which they are bonded, and —CH ₂ — contained in the ring may be —O—, —S ( O)- or -CO- may be substituted.
R ^b13 to R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents -S- or -O-.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5;
q2 and r2 each independently represent an integer of 0 to 4;
u2 represents 0 or 1;
When o2 is 2 or more, the plurality of R ^b13 may be the same or different, when p2 is 2 or more, the plurality of R ^b14 may be the same or different, and when q2 is 2 or more , the plurality of R ^b15 may be the same or different, when r2 is 2 or more, the plurality of R ^b16 may be the same or different, and when s2 is 2 or more, the plurality of R ^b17 may be They may be the same or different, and when t2 is 2 or more, a plurality of R ^b18 may be the same or different. ]

［式（ＩＩ－２－Ａ）中、Ｒ^ＩＩＩ３、Ｘ^ＩＩＩ３及びＺ^ａ＋は、上記と同じ意味を表す。
Ｚは、０～６の整数を表す。
Ｒ^ＩＩＩ２及びＲ^ＩＩＩ４は、それぞれ独立して、水素原子、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表し、ｚが２以上のとき、複数のＲ^ＩＩＩ２及びＲ^ＩＩＩ４は互いに同一であってもよいし、異なっていてもよい。
Ｑ^ａ及びＱ^ｂは、それぞれ独立して、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。］ The structural unit represented by formula (II-2-A') is preferably a structural unit represented by formula (II-2-A).

[In formula (II-2-A), R ^III3 , X ^III3 and Z ^a+ have the same meanings as above.
Z represents an integer of 0-6.
R ^III2 and R ^III4 each independently represent a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms, and when z is 2 or more, a plurality of R ^III2 and R ^III4 are the same may be different.
Q ^a and Q ^b each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group. ]

The perfluoroalkyl group having 1 to 6 carbon atoms represented by R ^III2 , R ^III4 , Q ^a and Q ^b includes the same perfluoroalkyl group having 1 to 6 carbon atoms as represented by Q ¹ .

［式（ＩＩ－２－Ａ－１）中、
Ｒ^ＩＩＩ２、Ｒ^ＩＩＩ３、Ｒ^ＩＩＩ４、Ｑ^a、Ｑ^b、ｚ及びＺ^a＋は、上記と同じ意味を表す。
Ｒ^ＩＩＩ５は、炭素数１～１２の飽和炭化水素基を表す。
Ｘ²は、炭素数１～１１の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子は、ハロゲン原子又はヒドロキシ基で置換されていてもよい。］ The structural unit represented by formula (II-2-A) is preferably a structural unit represented by formula (II-2-A-1).

[In formula (II-2-A-1),
R ^III2 , R ^III3 , R ^III4 , Q ^a , Q ^b , z and Z ^a+ have the same meanings as above.
R ^III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
X ² represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O—, —S— or —CO—. A hydrogen atom contained in the saturated hydrocarbon group may be substituted with a halogen atom or a hydroxy group. ]

Examples of saturated hydrocarbon groups having 1 to 12 carbon atoms represented by R ^III5 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Linear or branched alkyl groups such as heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group can be mentioned.
The divalent saturated hydrocarbon group having 1 to 11 carbon atoms represented by X ² includes those having up to 11 carbon atoms among the divalent saturated hydrocarbon groups represented by X ^III3 .

［式（ＩＩ－２－Ａ－２）中、Ｒ^ＩＩＩ３、Ｒ^ＩＩＩ５及びＺ^a＋は、上記と同じ意味を表す。
ｍ及びｎは、互いに独立に、１又は２を表す。］ As the structural unit represented by formula (II-2-A), a structural unit represented by formula (II-2-A-2) is more preferable.

[In formula (II-2-A-2), R ^III3 , R ^III5 and Z ^a+ have the same meanings as above.
m and n each independently represent 1 or 2; ]

Examples of structural units represented by formula (II-2-A-1) include the following structural units and structural units described in WO2012/050015. Z ^a+ represents an organic cation.

［式（ＩＩ－１－１）中、
Ａ^ＩＩ１は、単結合又は２価の連結基を表す。
Ｒ^ＩＩ１は、炭素数６～１８の２価の芳香族炭化水素基を表す。
Ｒ^ＩＩ２及びＲ^ＩＩ３は、それぞれ独立して、炭素数１～１８の炭化水素基を表し、Ｒ^ＩＩ２及びＲ^ＩＩ３は互いに結合してそれらが結合する硫黄原子とともに環を形成していてもよい。
Ｒ^ＩＩ４は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１～６のアルキル基を表す。
Ａ’^－は、有機アニオンを表す。］
Ａ^ＩＩ１で表される２価の連結基としては、例えば、炭素数１～１８の２価の飽和炭化水素基が挙げられ、該２価の飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－又は－ＣＯ－で置き換わっていてもよい。具体的には、Ｘ^ＩＩＩ３で表される炭素数１～１８の２価の飽和炭化水素基と同じものが挙げられる。
Ｒ^ＩＩ１で表される炭素数６～１８の２価の芳香族炭化水素基としては、フェニレン基及びナフチレン基等が挙げられる。
Ｒ^ＩＩ２及びＲ^ＩＩ３で表される炭素数１～１８の炭化水素基としては、式（２）のＲ^ａ３’で表される炭素数１～１８の炭化水素基と同じものが挙げられる。
Ｒ^ＩＩ４で表されるハロゲン原子としては、フッ素原子、塩素原子、臭素原子及びヨウ素原子等が挙げられる。
Ｒ^ＩＩ４で表されるハロゲン原子を有していてもよい炭素数１～６のアルキル基としては、Ｒ^ａ８で表されるハロゲン原子を有していてもよい炭素数１～６のアルキル基と同じものが挙げられる。 A structural unit having a sulfonio group and an organic anion in a side chain is preferably a structural unit represented by formula (II-1-1).

[In the formula (II-1-1),
^AII1 represents a single bond or a divalent linking group.
R ^II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^II2 and R ^II3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and R ^II2 and R ^II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
R ^II4 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
A'- represents an organic ^anion . ]
The divalent linking group represented by A ^II1 includes, for example, a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is -O-, -S- or -CO- may be substituted. Specific examples thereof include the same divalent saturated hydrocarbon groups having 1 to 18 carbon atoms represented by X ^III3 .
Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R ^II1 include a phenylene group and a naphthylene group.
The hydrocarbon group having 1 to 18 carbon atoms represented by R 1 ^II2 and R 1 ^II3 includes the same hydrocarbon group having 1 to 18 carbon atoms as represented by R ^a3′ in formula (2).
Halogen atoms represented by ^RII4 include fluorine, chlorine, bromine and iodine atoms.
The alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^II4 includes an alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^a8 . The same can be mentioned.

Examples of structural units containing cations in formula (II-1-1) include structural units represented below.

Examples of the organic anions represented by A'- include sulfonate anions ^, sulfonylimide anions, sulfonylmethide anions and carboxylate anions. Specifically, the same organic anions as those represented ^by A- mentioned.
The organic ^anion represented by A'- is preferably a sulfonate anion, more preferably an anion represented by formula (IA).

Examples of the structural unit (II-1) include structural units represented below.

When the resin (A) contains the structural unit (II), the content of the structural unit (II) is preferably 1 to 20 mol% of the total structural units of the resin (A), and more It is preferably 2 to 15 mol %, more preferably 3 to 10 mol %.

Resin (A) is preferably a resin composed of structural unit (a1) and structural unit (s), that is, a copolymer of monomer (a1) and monomer (s).
Structural unit (a1) is preferably at least one selected from structural unit (a1-1) and structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), more preferably a structural unit ( a1-1) or at least two selected from the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group).
Structural unit (s) is preferably at least one of structural unit (a2) and structural unit (a3). Structural unit (a2) is preferably a structural unit represented by formula (a2-1). Structural unit (a3) is preferably a structural unit represented by formula (a3-1-1) or (a3-1-2), formula (a3-2-1) or formula (a3-2-2) and at least one selected from structural units represented by formulas (a3-4-1) to (a3-4-2).

Each structural unit that constitutes the resin (A) may be used alone or in combination of two or more. Using a monomer that induces these structural units, it is produced by a known polymerization method (e.g., radical polymerization method). can do. The content of each structural unit in the resin (A) can be adjusted by adjusting the amount of monomer used for polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, further preferably is 15,000 or less). As used herein, the weight average molecular weight is a value obtained by gel permeation chromatography under the conditions described in Examples.

<Resin (X) other than resin (A)>
The resist composition of the present invention may contain a resin other than resin (A). Examples of such a resin include a resin containing the structural unit (a4) (hereinafter sometimes referred to as "resin (X)").
Structural units that the resin (X) may further include structural units (a1), structural units (a2), structural units (a3), structural units (a5) and other known structural units.
More preferably, the resin (X) is a resin comprising structural units (a4) and/or structural units (a5).
When the resin (X) contains the structural unit (a4), the content thereof is preferably 40 mol% or more, more preferably 45 mol% or more, and 50 mol% or more, based on the total structural units of the resin (X). is more preferred.
When the resin (X) contains the structural unit (a5), its content is preferably 10 to 60 mol%, more preferably 20 to 55 mol%, more preferably 25 to 50 mol % is more preferred.

Each structural unit that constitutes the resin (X) may be used alone or in combination of two or more. Using a monomer that induces these structural units, the resin (X) is produced by a known polymerization method (e.g., radical polymerization method). can do. The content of each structural unit in the resin (X) can be adjusted by adjusting the amount of the monomer used for polymerization.
The weight average molecular weight of resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight-average molecular weight of resin (X) is the same as for resin (A).
When the resist composition contains resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, relative to 100 parts by mass of resin (A). It is preferably 1 to 40 parts by mass, particularly preferably 2 to 30 parts by mass.

The total content of the resin (A) and the resin other than the resin (A) is preferably 80% by mass or more and 99% by mass or less, preferably 90% by mass or more and 99% by mass or less, relative to the solid content of the resist composition. . The solid content and resin content of the resist composition can be measured by known analytical means such as liquid chromatography or gas chromatography.

<Solvent (E)>
The content of the solvent (E) is usually 90% by mass or more, preferably 92% by mass or more, more preferably 94% by mass or more, and 99.9% by mass or less, preferably 99% by mass or less in the resist composition. is. The content of the solvent (E) can be measured by known analytical means such as liquid chromatography or gas chromatography.

Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; One type of solvent (E) may be contained alone, or two or more types may be contained.

<Quencher (C)>
The resist composition of the present invention may contain a quencher (hereinafter sometimes referred to as "quencher (C)"). The quencher (C) includes a basic nitrogen-containing organic compound or a salt that generates a weaker acid than the acid generator (B).

<Basic nitrogen-containing organic compound>
Basic nitrogen-containing organic compounds include amines and ammonium salts. Amines include aliphatic amines and aromatic amines. Aliphatic amines include primary, secondary and tertiary amines.

Specifically, 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine , heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine , ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino- 3,3′-diethyldiphenylmethane, 2,2′-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridyl)ethane, 1,2-di(4 -pyridyl)ethane, 1,2-di(2-pyridyl)ethene, 1,2-di(4-pyridyl)ethene, 1,3-di(4-pyridyl)propane, 1,2-di(4-pyridyl) oxy)ethane, di(2-pyridyl)ketone, 4,4'-dipyridylsulfide, 4,4'-dipyridyldisulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, bipyridine and the like. , preferably diisopropylaniline, and particularly preferably 2,6-diisopropylaniline.

Ammonium salts include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethyl ammonium hydroxide, tetra-n-butylammonium salicylate and choline;

<Salts that generate weakly acidic acids>
The acidity of a salt that generates an acid that is weaker than the acid generated from the acid generator is indicated by the acid dissociation constant (pKa). The salt that generates an acid weaker in acidity than the acid generated from the acid generator is a salt with a pKa of -3<pKa, preferably -1<pKa<7. and more preferably a salt with 0<pKa<5. Salts that generate an acid weaker than the acid generated from the acid generator include salts represented by the following formula, weak acid inner salts represented by formula (D) described in JP-A-2015-147926, and particularly Examples include salts described in JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502 and JP-A-2011-191745.

The weak acid inner salt (D) includes the following salts.

The content of the quencher (C) in the solid content of the resist composition is preferably 0.01 to 5% by mass, more preferably 0.01 to 4% by mass, and particularly preferably 0.01 to 3%. % by mass.

<Other ingredients>
If necessary, the resist composition of the present invention may contain components other than the components described above (hereinafter sometimes referred to as "other components (F)"). Other components (F) are not particularly limited, and additives known in the field of resists, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, etc., can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises the salt (I) of the present invention, resin (A) and acid generator (B), and optionally resin (X), quencher (C), solvent (E) and It can be prepared by mixing other components (F). The mixing order is arbitrary and not particularly limited. The temperature during mixing can be appropriately selected from 10 to 40° C. depending on the type of resin or the like and the solubility of the resin or the like in the solvent (E). An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is also not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) a step of applying the resist composition of the present invention onto a substrate;
(2) a step of drying the applied composition to form a composition layer;
(3) exposing the composition layer;
(4) heating the exposed composition layer; and (5) developing the heated composition layer.

The coating of the resist composition on the substrate can be carried out using a commonly used device such as a spin coater. Examples of substrates include inorganic substrates such as silicon wafers. Before applying the resist composition, the substrate may be washed, or an antireflection film or the like may be formed on the substrate.

By drying the applied composition, the solvent is removed and a composition layer is formed. Drying is carried out, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or by using a decompression device. The heating temperature is preferably 50 to 200° C., and the heating time is preferably 10 to 180 seconds. The pressure for drying under reduced pressure is preferably about 1 to 1.0×10 ⁵ Pa.

The resulting composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. As the exposure light source, a KrF excimer laser (wavelength: 248 nm), an ArF excimer laser (wavelength: 193 nm), an F2 excimer laser ₍ wavelength: 157 nm) that emits a laser beam in the ultraviolet region, a solid-state laser source (YAG or semiconductor laser etc.) and emits harmonic laser light in the far ultraviolet region or vacuum ultraviolet region by wavelength conversion, electron beam, and extreme ultraviolet light (EUV). can be done. In this specification, these irradiations with radiation may be collectively referred to as "exposure". During exposure, exposure is usually performed through a mask corresponding to the desired pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask.

The exposed composition layer is subjected to a heat treatment (so-called post-exposure bake) in order to promote the deprotection reaction at the acid-labile groups. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C.

The composition layer after heating is usually developed using a developer using a developing device. The developing method includes a dipping method, a paddle method, a spraying method, a dynamic dispensing method, and the like. The developing temperature is preferably 5 to 60° C., and the developing time is preferably 5 to 300 seconds. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. Examples thereof include aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline). The alkaline developer may contain a surfactant.
After development, the resist pattern is preferably washed with ultrapure water, and then water remaining on the substrate and pattern is removed.

When producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as "organic developer") is used as the developer.
Examples of organic solvents contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether. ether solvents; amide solvents such as N,N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole;
The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and still more preferably substantially only the organic solvent.
Among them, as the organic developer, a developer containing butyl acetate and/or 2-heptanone is preferable. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially contains butyl acetate and/or 2-heptanone. - more preferably only heptanone.
The organic developer may contain a surfactant. In addition, the organic developer may contain a trace amount of water.
During development, the development may be stopped by replacing the organic developer with a solvent of a different type.

It is preferable to wash the resist pattern after development with a rinsing liquid. The rinse liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent.
After cleaning, it is preferable to remove the rinse liquid remaining on the substrate and pattern.

<Application>
The resist composition of the present invention is a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure. It is suitable as a resist composition for line (EB) exposure or as a resist composition for EUV exposure, and is useful for microfabrication of semiconductors.

EXAMPLES The present invention will be described more specifically with reference to examples. In the examples, "%" and "parts" representing the content or amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value obtained by gel permeation chromatography under the following conditions.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min
Detector: RI detector Column temperature: 40°C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent Model 1100, MASS: Agilent Model LC/MSD). In the following examples, the value of this molecular ion peak is indicated by "MASS".

式（Ｉ－３－ａ）で表される塩１０．８部及びクロロホルム６０部を混合した後、２３℃で３０分間攪拌した。得られた混合物を、強塩基イオン交換樹脂でアニオン交換することにより、式（Ｉ－３－ｂ）で表される塩を含む溶液を得た。得られた式（Ｉ－３－ｂ）で表される塩を含む溶液に、式（Ｉ－３－ｃ）で表される塩８．９部及びイオン交換水３０部を添加し、２３℃で１２時間攪拌した。得られた混合物を分液して有機層を取り出した。回収された有機層にイオン交換水３０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を２回繰り返した。得られた残渣を濃縮した後、得られた残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて攪拌した後、上澄み液を除去した。得られた残渣を濃縮した後、ｎ－ヘプタン３０部を加えて攪拌した後、ろ過することにより、式（Ｉ－３）で表される塩９．３１部を得た。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３８９．０
ＭＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３２３．０ Example 1: Synthesis of salt represented by formula (I-3)

After mixing 10.8 parts of the salt represented by formula (I-3-a) and 60 parts of chloroform, the mixture was stirred at 23° C. for 30 minutes. The obtained mixture was subjected to anion exchange with a strong base ion exchange resin to obtain a solution containing a salt represented by formula (I-3-b). 8.9 parts of the salt represented by the formula (I-3-c) and 30 parts of ion-exchanged water were added to the obtained solution containing the salt represented by the formula (I-3-b), and the mixture was heated to 23°C. and stirred for 12 hours. The obtained mixture was liquid-separated and the organic layer was taken out. After adding 30 parts of ion-exchanged water to the collected organic layer and stirring at 23° C. for 30 minutes, the organic layer was taken out by liquid separation. This washing operation was repeated twice. After concentrating the obtained residue, 30 parts of tert-butyl methyl ether was added to the obtained residue and stirred, and then the supernatant was removed. After concentrating the resulting residue, 30 parts of n-heptane was added and the mixture was stirred and filtered to obtain 9.31 parts of the salt represented by the formula (I-3).
MS (ESI (+) Spectrum): M ⁺ 389.0
MS (ESI (-) Spectrum): M ^- 323.0

式（Ｉ－３）で表される塩８．５部、式（Ｉ－２４－ｂ）で表される化合物６．５部、クロロホルム３５部、アセトニトリル１４部及びジメチルホルムアミド１４部を混合し、２３℃で３０分間攪拌した。得られた混合物に、ｐ－トルエンスルホン酸０．０７部を添加し、３時間還流攪拌した。得られた混合物を２３℃まで冷却し、クロロホルム１５５部を添加撹拌後、ろ過した。回収されたろ液に、５％炭酸水素ナトリウム水溶液４０部を加え、２３℃で３０分間攪拌した。その後、静置し、分液した。回収された有機層に、イオン交換水４５部を混合して２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を３回行った。得られた有機層に酢酸エチル９５部を加えて攪拌した後、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－２４－ｃ）で表される塩６部を得た。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３８９．０
ＭＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ４４１．１ Example 2: Synthesis of salt represented by formula (I-24-c)

8.5 parts of the salt represented by the formula (I-3), 6.5 parts of the compound represented by the formula (I-24-b), 35 parts of chloroform, 14 parts of acetonitrile and 14 parts of dimethylformamide are mixed, Stirred at 23° C. for 30 minutes. 0.07 part of p-toluenesulfonic acid was added to the resulting mixture, and the mixture was stirred under reflux for 3 hours. The obtained mixture was cooled to 23° C., 155 parts of chloroform was added, and the mixture was filtered after stirring. 40 parts of a 5% sodium hydrogencarbonate aqueous solution was added to the collected filtrate, and the mixture was stirred at 23° C. for 30 minutes. After that, it was allowed to stand and liquid-separated. The recovered organic layer was mixed with 45 parts of ion-exchanged water, stirred at 23° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed three times. After adding 95 parts of ethyl acetate to the obtained organic layer and stirring, the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 6 parts of the salt represented by the formula (I-24-c).
MS (ESI (+) Spectrum): M ⁺ 389.0
MS (ESI (-) Spectrum): M ^- 441.1

式（Ｉ－２４－ｄ）で表される化合物２．２部及びアセトニトリル８．８部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－２４－ｅ）で表される化合物１．９部を１５分かけて添加し、５０℃で１時間攪拌した。得られた混合物に、式（Ｉ－２４－ｃ）で表される塩２．４部を加え、５０℃で１０時間攪拌後した。得られた混合物を２３℃まで冷却し、クロロホルム１１０部及びイオン交換水３５部を添加撹拌し、静置し、分液した。回収された有機層に、イオン交換水３５部を加えて２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を７回行った。得られた有機層を濃縮し、得られた残渣に、アセトニトリル３部、酢酸エチル２０部及びｔｅｒｔ－ブチルメチルエーテル２０部を加えて２３℃で３０分間攪拌し、上澄み液を除去し、濃縮することにより、式（Ｉ－２４）で表される塩１．９部を得た。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３８９．０
ＭＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ７９３．３ Example 3: Synthesis of salt represented by formula (I-24)

2.2 parts of the compound represented by formula (I-24-d) and 8.8 parts of acetonitrile were mixed and stirred at 23° C. for 30 minutes. To the resulting mixture, 1.9 parts of the compound represented by formula (I-24-e) was added over 15 minutes and stirred at 50°C for 1 hour. 2.4 parts of the salt represented by the formula (I-24-c) was added to the obtained mixture, and the mixture was stirred at 50° C. for 10 hours. The resulting mixture was cooled to 23° C., 110 parts of chloroform and 35 parts of ion-exchanged water were added, stirred, allowed to stand, and separated. 35 parts of ion-exchanged water was added to the recovered organic layer, and the mixture was stirred at 23° C. for 30 minutes to separate the layers, thereby recovering the organic layer. This washing operation was performed seven times. The obtained organic layer is concentrated, 3 parts of acetonitrile, 20 parts of ethyl acetate and 20 parts of tert-butyl methyl ether are added to the obtained residue, stirred at 23° C. for 30 minutes, the supernatant is removed, and the mixture is concentrated. Thus, 1.9 parts of the salt represented by the formula (I-24) was obtained.
MS (ESI (+) Spectrum): M ⁺ 389.0
MS (ESI (-) Spectrum): M ^- 793.3

式（Ｉ－２２７－ａ）で表される塩１０．７６部及びクロロホルム６０部を混合した後、２３℃で３０分間攪拌した。得られた混合物を、強塩基イオン交換樹脂でアニオン交換することにより、式（Ｉ－２２７－ｂ）で表される塩を含む溶液を得た。得られた式（Ｉ－２２７－ｂ）で表される塩を含む溶液に、式（Ｉ－３－ｃ）で表される塩８．９４部及びイオン交換水３０部を添加し、２３℃で１２時間攪拌した。得られた混合物を分液して有機層を取り出した。回収された有機層にイオン交換水３０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を２回繰り返した。得られた残渣を濃縮した後、得られた残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて攪拌した後、上澄み液を除去した。得られた残渣を濃縮した後、ｎ－ヘプタン３０部を加えて攪拌した後、ろ過することにより、式（Ｉ－２２７）で表される塩８．５４部を得た。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３８７．０
ＭＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３２３．０ Example 4: Synthesis of salt represented by formula (I-227)

After mixing 10.76 parts of the salt represented by the formula (I-227-a) and 60 parts of chloroform, the mixture was stirred at 23° C. for 30 minutes. The obtained mixture was subjected to anion exchange with a strong base ion exchange resin to obtain a solution containing a salt represented by formula (I-227-b). 8.94 parts of the salt represented by the formula (I-3-c) and 30 parts of ion-exchanged water were added to the resulting solution containing the salt represented by the formula (I-227-b), and the mixture was heated to 23°C. for 12 hours. The obtained mixture was liquid-separated and the organic layer was taken out. After adding 30 parts of ion-exchanged water to the collected organic layer and stirring at 23° C. for 30 minutes, the organic layer was taken out by liquid separation. This washing operation was repeated twice. After concentrating the obtained residue, 30 parts of tert-butyl methyl ether was added to the obtained residue and stirred, and then the supernatant was removed. After concentrating the resulting residue, 30 parts of n-heptane was added and the mixture was stirred and filtered to obtain 8.54 parts of the salt represented by the formula (I-227).
MS (ESI (+) Spectrum): M ⁺ 387.0
MS (ESI (-) Spectrum): M ^- 323.0

式（Ｉ－２２７）で表される塩８．４８部、式（Ｉ－２４－ｂ）で表される化合物６．５部、クロロホルム３５部、アセトニトリル１４部及びジメチルホルムアミド１４部を混合し、２３℃で３０分間攪拌した。得られた混合物に、ｐ－トルエンスルホン酸０．０７部を添加し、３時間還流攪拌した。得られた混合物を２３℃まで冷却し、クロロホルム１５５部を添加撹拌後、ろ過した。回収されたろ液に、５％炭酸水素ナトリウム水溶液４０部を加え、２３℃で３０分間攪拌した。その後、静置し、分液した。回収された有機層に、イオン交換水４５部を混合して２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を３回行った。得られた有機層に酢酸エチル９５部を加えて攪拌した後、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－２４８－ｃ）で表される塩５．８９部を得た。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３８７．０
ＭＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ４４１．１ Example 5: Synthesis of salt represented by formula (I-248-c)

8.48 parts of the salt represented by the formula (I-227), 6.5 parts of the compound represented by the formula (I-24-b), 35 parts of chloroform, 14 parts of acetonitrile and 14 parts of dimethylformamide are mixed, Stirred at 23° C. for 30 minutes. 0.07 part of p-toluenesulfonic acid was added to the resulting mixture, and the mixture was stirred under reflux for 3 hours. The obtained mixture was cooled to 23° C., 155 parts of chloroform was added, and the mixture was filtered after stirring. 40 parts of a 5% sodium hydrogencarbonate aqueous solution was added to the collected filtrate, and the mixture was stirred at 23° C. for 30 minutes. After that, it was allowed to stand and liquid-separated. The recovered organic layer was mixed with 45 parts of ion-exchanged water, stirred at 23° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed three times. After adding 95 parts of ethyl acetate to the obtained organic layer and stirring, the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 5.89 parts of the salt represented by the formula (I-248-c).
MS (ESI (+) Spectrum): M ⁺ 387.0
MS (ESI (-) Spectrum): M ^- 441.1

式（Ｉ－２４－ｄ）で表される化合物２．２部及びアセトニトリル８．８部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－２４－ｅ）で表される化合物１．９部を１５分かけて添加し、５０℃で１時間攪拌した。得られた混合物に、式（Ｉ－２４８－ｃ）で表される塩２．３９部を加え、５０℃で１０時間攪拌後した。得られた混合物を２３℃まで冷却し、クロロホルム１１０部及びイオン交換水３５部を添加撹拌し、静置し、分液した。回収された有機層に、イオン交換水３５部を加えて２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を７回行った。得られた有機層を濃縮し、得られた残渣に、アセトニトリル３部、酢酸エチル２０部及びｔｅｒｔ－ブチルメチルエーテル２０部を加えて２３℃で３０分間攪拌し、上澄み液を除去し、濃縮することにより、式（Ｉ－２４８）で表される塩１．３８部を得た。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３８７．０
ＭＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ７９３．３ Example 6: Synthesis of salt represented by formula (I-248)

2.2 parts of the compound represented by formula (I-24-d) and 8.8 parts of acetonitrile were mixed and stirred at 23° C. for 30 minutes. To the resulting mixture, 1.9 parts of the compound represented by formula (I-24-e) was added over 15 minutes and stirred at 50°C for 1 hour. To the obtained mixture, 2.39 parts of the salt represented by the formula (I-248-c) was added, and the mixture was stirred at 50°C for 10 hours. The resulting mixture was cooled to 23° C., 110 parts of chloroform and 35 parts of ion-exchanged water were added, stirred, allowed to stand, and separated. 35 parts of ion-exchanged water was added to the recovered organic layer, and the mixture was stirred at 23° C. for 30 minutes to separate the layers, thereby recovering the organic layer. This washing operation was performed seven times. The obtained organic layer is concentrated, 3 parts of acetonitrile, 20 parts of ethyl acetate and 20 parts of tert-butyl methyl ether are added to the obtained residue, stirred at 23° C. for 30 minutes, the supernatant is removed, and the mixture is concentrated. Thus, 1.38 parts of a salt represented by the formula (I-248) was obtained.
MS (ESI (+) Spectrum): M ⁺ 387.0
MS (ESI (-) Spectrum): M ^- 793.3

式（Ｉ－２２７－ａ）で表される塩１０．７６部及びクロロホルム６０部を混合した後、２３℃で３０分間攪拌した。得られた混合物を、強塩基イオン交換樹脂でアニオン交換することにより、式（Ｉ－２２７－ｂ）で表される塩を含む溶液を得た。得られた式（Ｉ－２２７－ｂ）で表される塩を含む溶液に、式（Ｉ－２６１－ｃ）で表される塩６．０３部及びイオン交換水３０部を添加し、２３℃で１２時間攪拌した。得られた混合物を分液して有機層を取り出した。回収された有機層にイオン交換水３０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を２回繰り返した。得られた残渣を濃縮した後、得られた残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて攪拌した後、上澄み液を除去した。得られた残渣を濃縮した後、ｎ－ヘプタン３０部を加えて攪拌した後、ろ過することにより、式（Ｉ－２６１）で表される塩２．３９部を得た。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３８７．０
ＭＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ２７９．９ Example 7: Synthesis of salt represented by formula (I-261)

After mixing 10.76 parts of the salt represented by the formula (I-227-a) and 60 parts of chloroform, the mixture was stirred at 23° C. for 30 minutes. The obtained mixture was subjected to anion exchange with a strong base ion exchange resin to obtain a solution containing a salt represented by formula (I-227-b). 6.03 parts of the salt represented by the formula (I-261-c) and 30 parts of ion-exchanged water were added to the resulting solution containing the salt represented by the formula (I-227-b), and the mixture was heated to 23°C. and stirred for 12 hours. The obtained mixture was liquid-separated and the organic layer was taken out. After adding 30 parts of ion-exchanged water to the collected organic layer and stirring at 23° C. for 30 minutes, the organic layer was taken out by liquid separation. This washing operation was repeated twice. After concentrating the obtained residue, 30 parts of tert-butyl methyl ether was added to the obtained residue and stirred, and then the supernatant was removed. After concentrating the resulting residue, 30 parts of n-heptane was added and the mixture was stirred and filtered to obtain 2.39 parts of the salt represented by the formula (I-261).
MS (ESI (+) Spectrum): M ⁺ 387.0
MS (ESI (-) Spectrum): M ^- 279.9

以下、これらのモノマーを式番号に応じて「モノマー（ａ１－１－１）」等という。 Synthesis of Resin The compounds (monomers) used in synthesizing the resin are shown below.

Hereinafter, these monomers are referred to as "monomer (a1-1-1)" and the like according to their formula numbers.

Synthesis Example 1 [Synthesis of resin A1]
As monomers, monomer (a1-4-2), monomer (a1-1-3), monomer (a1-2-6), monomer (a3-1-1) and monomer (II-2-A-1-1 ), the molar ratio [monomer (a1-4-2): monomer (a1-1-3): monomer (a1-2-6): monomer (a3-4-2): monomer (II-2- A-1-1)] are mixed in a ratio of 32:25:35:5:3, and further, to this monomer mixture, 1.5 times the mass of methyl Isobutyl ketone was mixed in. To the resulting mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to polymerize. did Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain a resin A1 (copolymer) having a weight average molecular weight of about 8.0×10 ³ with a yield of 68. obtained in %. This resin A1 has the following structural units.

Synthesis Example 2 [Synthesis of resin A2]
As monomers, monomer (a1-4-2), monomer (a1-1-3), monomer (a1-2-6) and monomer (a3-1-1) are used, and the molar ratio [monomer (a1-4 -2): Monomer (a1-1-3): Monomer (a1-2-6): Monomer (a3-4-2)] were mixed in a ratio of 35:25:35:5. A resin A2 (copolymer) having a weight average molecular weight of about 8.0×10 ³ was obtained in a yield of 65% by the same method as in Example 1. This resin A2 has the following structural units.

Synthesis Example 3 [Synthesis of Resin A3]
As monomers, monomer (a1-4-2), monomer (a1-1-3) and monomer (a1-2-6) are used, and the molar ratio [monomer (a1-4-2):monomer (a1-1 -3): Monomer (a1-2-6)] were mixed in a ratio of 35:25:40 in the same manner as in Synthesis Example 1, and the weight average molecular weight was about 7.6×10 ³ . A resin A3 (copolymer) was obtained in 64% yield. This resin A3 has the following structural units.

Synthesis Example 4 [Synthesis of Resin A4]
As monomers, monomer (a2-2-1), monomer (a1-1-3), monomer (a1-2-6) and monomer (a3-1-1) are used, and the molar ratio [monomer (a1-4 -2): Monomer (a1-1-3): Monomer (a1-2-6): Monomer (a3-4-2)] are mixed in a ratio of 35:25:35:5, and , 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed into this monomer mixture. To the resulting mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% with respect to the total number of moles of all monomers, and the mixture was heated at 75°C for about 5 hours to polymerize. did The resulting reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate the resin, which was filtered. The resulting resin was added to a mixed solvent of methanol/water, repulp, and then subjected to a refining operation of filtering twice to give a resin A4 (copolymer) having a weight average molecular weight of about 8.1×10 ³ . Obtained with a yield of 61%. This resin A4 has the following structural units.

<Preparation of resist composition>
Each of the components shown below was mixed in parts by mass shown in Table 2, dissolved in a solvent, and filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

Ｂ１－Ｘ１：特開２０１４－２３５２４８号公報記載の方法で合成
Ｂ１－Ｘ２：特開２０１４－２３５２４８号公報記載の方法で合成
Ｂ１－Ｘ３：カチオン置換基のヨウ素原子をフッ素原子に置き換える以外は実施例１と同様にして合成
Ｂ１－Ｘ４：カチオン置換基のヨウ素原子を塩素原子に置き換える以外は実施例１と同様にして合成
Ｂ１－Ｘ５：カチオン置換基のヨウ素原子を臭素原子に置き換える以外は実施例１と同様にして合成

<Resin (A)>
A1 to A4: Resin A1 to Resin A4
<Acid generator (B)>
B1-25: a salt represented by the formula (B1-25); synthesized by the method described in JP-A-2011-126869 B1-41: a salt represented by the formula (B1-41); JP-A-2016-047815 Synthesized by the method described in the publication

B1-X1: synthesized by the method described in JP-A-2014-235248 B1-X2: synthesized by the method described in JP-A-2014-235248 B1-X3: carried out except replacing the iodine atom of the cation substituent with a fluorine atom Synthesized in the same manner as in Example 1 B1-X4: Synthesized in the same manner as in Example 1 except that the iodine atom of the cationic substituent is replaced with a chlorine atom B1-X5: Performed except that the iodine atom of the cationic substituent is replaced with a bromine atom Synthesized in the same manner as in Example 1

Ｄ１：（東京化成工業（株）製）

＜溶剤（Ｅ）＞
プロピレングリコールモノメチルエーテルアセテート ４００部
プロピレングリコールモノメチルエーテル １００部
γ－ブチロラクトン ５部 <Quencher (C)>
C1: synthesized by the method described in JP-A-2011-39502

D1: (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Solvent (E)>
Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 100 parts γ-butyrolactone 5 parts

(Evaluation of resist composition by electron beam exposure)
A 6-inch silicon wafer was treated with hexamethyldisilazane at 90° C. for 60 seconds on a direct hotplate. This silicon wafer was spin-coated with the resist composition so that the film thickness of the composition layer was 0.04 μm. After that, it was pre-baked for 60 seconds on a direct hot plate at the temperature shown in the "PB" column of Table 2 to form a composition layer. A line-and-space pattern was directly drawn on the composition layer formed on the wafer using an electron beam lithography machine ["HL-800D 50 keV" manufactured by Hitachi, Ltd.] while changing the exposure dose stepwise. .
After exposure, post-exposure baking was performed on a hot plate at the temperature shown in the "PEB" column of Table 2 for 60 seconds, and puddle development was performed for 60 seconds with a 2.38% by mass tetramethylammonium hydroxide aqueous solution. , a resist pattern was obtained.
The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the effective sensitivity was defined as the exposure dose at which the line width and space width of the 60 nm line and space pattern were 1:1.

Line Edge Roughness Evaluation (LER): Line edge roughness was obtained by measuring the unevenness amplitude of the side wall surface of the resist pattern manufactured at effective sensitivity with a scanning electron microscope. Table 3 shows the results.

The resist composition of the present invention has good line edge roughness and is useful for fine processing of semiconductors.

Claims (5)

a sulfonium cation represented by any one of formulas (Ic-1) to (Ic-10);
an acid generator containing a salt consisting of an organic anion represented by formula (IA);
and a resin having an acid-labile group.

[In the formula (IA),
Q ¹ and Q ² each represent a fluorine atom.
L ^b1 represents a group represented by formula (b1-4).

(In formula (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. * represents a bond with Y; )
Y is a first alicyclic hydrocarbon group having 3 to 18 carbon atoms, and —CH ₂ — contained in the first alicyclic hydrocarbon group is replaced with —O— or —CO— Alternatively, the first alicyclic hydrocarbon group contains an adamantyl group and is a halogen atom, a hydroxy group, a hydroxymethyl group, a hydroxyethyl group or a —(CH ₂ ) _ja —O—CO—R ^b1 group. may have.
ja represents any integer from 0 to 4;
R ^b1 is a second alicyclic hydrocarbon group having 3 to 16 carbon atoms, the second alicyclic hydrocarbon group contains an adamantyl group, and may have a fluorine atom or a hydroxyl group. Often, -CH ₂ - contained in the second alicyclic hydrocarbon group may be replaced with -O-, SO ₂ - or -CO-. ] 2. The resist composition according to claim 1, wherein the first alicyclic hydrocarbon group is a group represented by any one of formulas (Y30), (Y31), (Y39) and (Y40).

2. The resist composition according to claim 1, wherein Y is an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, or a group represented below.

4. The resist composition according to any one of claims 1 to 3, further comprising a salt that generates an acid of lower acidity than the acid generated from said acid generator. (1) a step of applying the resist composition according to any one of claims 1 to 4 onto a substrate;
(2) a step of drying the applied composition to form a composition layer;
(3) exposing the composition layer;
(4) heating the composition layer after exposure; and (5) developing the composition layer after heating;
A method of manufacturing a resist pattern comprising: