JP2022161021A - Resist composition and method for producing resist pattern - Google Patents

Abstract

To provide a resist composition from which a resist pattern having a good focus margin (DOF) can be produced.SOLUTION: The resist composition contains a compound represented by formula (I), a resin having an acid-labile group, and an acid generator. [In the formula, ring W represents an alicyclic hydrocarbon group containing an ether bond; and L1 represents a single bond or an optionally substituted alkanediyl group.]SELECTED DRAWING: None

Description

The present invention relates to a resist composition and a method for producing a resist pattern using the resist composition.

Patent Document 1 describes a resist composition containing a compound of the following structural formula, a resin having an acid-labile group, and an acid generator.

International publication 2019/064976

An object of the present invention is to provide a resist composition that forms a resist pattern with a better focus margin (DOF) than the resist pattern formed from the above resist composition.

［式（Ｉ）中、
環Ｗは、炭素数３～３６のエーテル結合を含む脂環式炭化水素基を表す。
Ｌ^１は、単結合又は置換基を有してもよい炭素数１～６のアルカンジイル基を表す。
Ｒ^１は、＊－Ｒ^１０、＊－ＣＯ－Ｒ^１０、＊－ＣＯ－Ｏ－Ｒ^１０、＊－Ｌ^２－ＣＯ－Ｏ－Ｒ^１０又は＊－ＣＯ－Ｏ－Ｌ^２－ＣＯ－Ｏ－Ｒ^１０を表し、＊は、－Ｏ－との結合部位を表す。
Ｒ^１０は、塩基不安定基を表す。
Ｌ^２は、置換基を有してもよい炭素数１～６のアルカンジイル基を表す。
Ｒ^２は、＊－Ｌ^１－Ｏ－Ｒ^１、＊－Ｌ^３（－Ｏ－Ｒ^１）_２又は式（Ｒ^２－１）で表される基を表し、＊は、環Ｗとの結合部位を表す。

Ｌ^３は、置換基を有してもよい炭素数１～６のアルカントリイル基を表す。
Ｒ^ab1及びＲ^ab2は、それぞれ独立に、水素原子、炭素数１～８のアルキル基、もしくは炭素数３～２０の脂環式炭化水素基を表すか、又はＲ^ab1及びＲ^ab2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の脂環式炭化水素基を形成し、該アルキル基及び該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－で置き換わってもよい。
ｍ２は、０～６のいずれかの整数を表し、ｍ２が１以上のとき、複数のＬ^１及び複数のＲ^１はそれぞれ互いに同一であっても異なってもよく、ｍ２が２以上のとき、複数のＲ^２は互いに同一であっても異なってもよい。
Ｒ^３は、ハロゲン原子、ヒドロキシ基、炭素数１～１２のハロアルキル基又は炭素数１～１２のアルキル基を表し、該アルキル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。２つのＲ^３は、一緒になってアセタール環構造を有する基を形成していてもよい。
ｍ３は、０～６のいずれかの整数を表し、ｍ３が２以上のとき、複数のＲ^３は互いに同一であっても異なってもよい。］
〔２〕Ｒ^１０の塩基不安定基が、式（１ｂ）で表される基である〔１〕に記載のレジスト組成物。

［式（１ｂ）中、Ｒ^ｂａ１及びＲ^ｂａ２は、それぞれ独立に、水素原子、フッ素原子又はフッ素原子を有する炭素数１～６のアルキル基を表す。
Ｒ^ｂａ３は、フッ素原子又はフッ素原子を有する炭素数１～６のアルキル基を表す。
＊は結合部位を表す。］
〔３〕酸不安定基を有する樹脂が、式（ａ１－０）で表される構造単位、式（ａ１－１）で表される構造単位及び式（ａ１－２）で表される構造単位からなる群より選ばれる少なくとも１種を含む〔１〕又は〔２〕に記載のレジスト組成物。

［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－との結合部位を表す。
Ｒ^ａ０１、Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、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。
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、炭素数６～１８の芳香族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２～８のアルケニル基、炭素数３～１８の脂環式炭化水素基、炭素数６～１８の芳香族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。］
〔４〕酸発生剤が、式（Ｂ１）で表される塩を含む〔１〕～〔３〕のいずれかに記載のレジスト組成物。

［式（Ｂ１）中、
Ｑ^ｂ１及びＱ^ｂ２は、それぞれ独立に、水素原子、フッ素原子、炭素数１～６のアルキル基又は炭素数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２価の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３～２４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－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ｚ１^＋は、有機カチオンを表す。］
〔５〕酸発生剤から発生する酸よりも酸性度の弱い酸を発生する塩をさらに含有する〔１〕～〔４〕のいずれかに記載のレジスト組成物。
〔６〕（１）〔１〕～〔５〕のいずれか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）組成物層に露光する工程、
（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 includes the following inventions.
[1] A resist composition containing a compound represented by formula (I), a resin having an acid-labile group, and an acid generator.

[in the formula (I),
Ring W represents an alicyclic hydrocarbon group containing an ether bond having 3 to 36 carbon atoms.
L ¹ represents a single bond or an optionally substituted alkanediyl group having 1 to 6 carbon atoms.
R ¹ is *-R ¹⁰ , *-CO-R ¹⁰ , *-CO-OR ¹⁰ , *-L ² -CO-O-R ¹⁰ or *-CO-OL ² -CO-O- represents R ¹⁰ and * represents the binding site with -O-.
R ¹⁰ represents a base labile group.
L ² represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms.
R ² represents *-L ¹ -OR ¹ , *-L ³ (-OR ¹ ) ₂ or a group represented by formula (R ² -1), * is a bond to ring W represents a part.

L ³ represents an optionally substituted alkanetriyl group having 1 to 6 carbon atoms.
R ^ab1 and R ^ab2 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group having 3 to 20 carbon ^{atoms ;} form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded, and —CH ₂ — contained in the alkyl group and the alicyclic hydrocarbon group is —O— or —CO - may be replaced.
m2 represents an integer of 0 to 6, and when m2 is 1 or more, the plurality of L ^1s and the plurality of R ^1s may be the same or different, and when m2 is 2 or more, A plurality of R ² may be the same or different from each other.
R ³ represents a halogen atom, a hydroxy group, a haloalkyl group having 1 to 12 carbon atoms or an alkyl group having 1 to 12 carbon atoms, and —CH ₂ — contained in the alkyl group is —O— or —CO—; may be replaced. Two ^R3 's may together form a group having an acetal ring structure.
m3 represents an integer of 0 to 6, and when m3 is ² or more, multiple R3's may be the same or different. ]
[2] The resist composition of [1], wherein the base-labile group of R ¹⁰ is a group represented by formula (1b).

[In the formula (1b), R ^ba1 and R ^ba2 each independently represent a hydrogen atom, a fluorine atom or a fluorine atom-containing alkyl group having 1 to 6 carbon atoms.
R ^ba3 represents a fluorine atom or a fluorine atom-containing alkyl group having 1 to 6 carbon atoms.
* represents a binding site. ]
[3] The resin having an acid-labile group is a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), and a structural unit represented by formula (a1-2). The resist composition according to [1] or [2], containing at least one selected from the group consisting of:

[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 the binding site with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom, a halogen atom or an optionally halogenated alkyl group having 1 to 6 carbon atoms.
R ^a02 , R ^a03 and R ^a04 are each independently an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or these Represents a combined group.
R ^a6 and R ^a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic group having 6 to 18 carbon atoms. It represents a hydrocarbon group or a group formed by combining these groups.
m1 represents any integer from 0 to 14;
n1 represents any integer from 0 to 10;
n1' represents an integer of 0 to 3; ]
[4] The resist composition according to any one of [1] to [3], wherein the acid generator contains a salt represented by formula (B1).

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO— , a hydrogen atom contained in the divalent saturated hydrocarbon 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 24 carbon atoms, included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -S-, -SO ₂ - or -CO-.
Z1 ⁺ represents an organic cation. ]
[5] The resist composition according to any one of [1] to [4], further comprising a salt that generates an acid weaker in acidity than the acid generated from the acid generator.
[6] (1) a step of applying the resist composition according to any one of [1] to [5] onto a substrate;
(2) a step of drying the applied composition to form a composition layer;
(3) exposing the composition layer;
(4) A method for producing a resist pattern, comprising the steps of: (4) heating the exposed composition layer; and (5) developing the heated composition layer.

By using the resist composition of the present invention, a resist pattern with a good focus margin (DOF) can be produced.

As used herein, "(meth)acrylic monomer" means "at least one of acrylic monomer and methacrylic monomer". Similarly, notations such as "(meth)acrylate" and "(meth)acrylic acid" have similar meanings. Any of the groups described in this specification that can have both a linear structure and a branched structure may be used. When —CH ₂ — contained in a hydrocarbon group or the like is replaced with —O—, —S—, —CO—, —SO— or —SO ₂ —, the same examples apply to each group. A "combined group" means a group in which two or more of the exemplified groups are combined, and the valences of these groups may be appropriately changed depending on the bonding form. "Derived from" or "derived from" refers to the polymerization of a polymerizable C=C bond contained in the molecule to a single bond (--C--C-- group). 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.

<Resist composition>
The resist composition of the present invention comprises a compound represented by formula (I) (hereinafter sometimes referred to as "compound (I)") and a resin having an acid-labile group (hereinafter sometimes referred to as "resin (A)"). ) and an acid generator (hereinafter sometimes referred to as "acid generator (B)"). The "acid-labile group" here has a leaving group, and upon contact with an acid, the leaving group is eliminated and converted into a structural unit having a hydrophilic group (e.g., hydroxy group or carboxy group). means the base.
The resist composition of the present invention may further contain a resin other than resin (A).
The resist composition of the present invention preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") such as a salt that generates an acid that is weaker in acidity than the acid generated by the acid generator. , a solvent (hereinafter sometimes referred to as "solvent (E)").

［式（Ｉ）中、全ての符号は、それぞれ前記と同じ意味を表す。］ <Compound (I)>
The resist composition of the present invention contains compound (I).

[In formula (I), all symbols have the same meanings as described above. ]

脂環式炭化水素基の炭素数は、好ましくは３～２４であり、より好ましくは３～１８であり、さらに好ましくは３～１６であり、より一層好ましくは３～１２であり、さらに一層好ましくは３～１０である。具体的には、エーテル結合を含む脂環式炭化水素基としては、シクロプロピル基、シクロブチル基、シクロペンチル基、シクロへキシル基、シクロオクチル基、シクロノニル基、シクロデシル基、シクロドデシル基等の単環式シクロアルキル基、ノルボルニル基、アダマンチル基等の多環式シクロアルキル基に含まれる任意の位置の－ＣＨ₂－が、－Ｏ－に置き換わった基から、（ｍ２＋ｍ３）個の水素原子が結合部位に置き換わった基が挙げられる。
環Ｗは、エーテル結合を少なくとも１つ含んでいればよく、２つ以上含んでいてもよい。
エーテル結合を含む脂環式炭化水素基としては、例えば、以下に表される基等が挙げられる。結合部位は任意の位置とすることができる。

The alicyclic hydrocarbon group containing an ether bond in ring W may be monocyclic, polycyclic or spirocyclic, and may be saturated or unsaturated. The alicyclic hydrocarbon group containing an ether bond includes, for example, a group in which —CH ₂ — at any position included in the following groups is replaced with —O—. The binding site can be at any position.

The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 24, more preferably 3 to 18, still more preferably 3 to 16, still more preferably 3 to 12, still more preferably is 3-10. Specifically, the alicyclic hydrocarbon group containing an ether bond includes monocyclic hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclononyl, cyclodecyl, and cyclododecyl groups. (m2+m3) hydrogen atoms from a group in which any position of —CH ₂ — contained in a polycyclic cycloalkyl group such as a cycloalkyl group, norbornyl group, and adamantyl group is replaced with —O— A group substituted with is mentioned.
Ring W may contain at least one ether bond, and may contain two or more.
Examples of the alicyclic hydrocarbon group containing an ether bond include groups represented below. The binding site can be at any position.

The alkanediyl group for L ¹ and L ² includes methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6 -linear alkanediyl group such as diyl group; and 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 and branched alkanediyl groups such as The number of carbon atoms in the alkanediyl group is preferably 1-4, more preferably 1-3.
The alkanetriyl group for L3 includes a methine group, an ^ethanetriyl group, a propanetriyl group, a butanetriyl group, a pentanetriyl group, a hexanetriyl group, and the like. The alkanetriyl group preferably has 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, and still more preferably 2 to 3 carbon atoms.
Examples of substituents which the alkanediyl groups of L ¹ and L ² and the alkanetriyl group of L ³ may have include a halogen atom, a hydroxy group, a cyano group, a carboxy group, an alkyl group having 1 to 12 carbon atoms, a carbon Examples include haloalkyl groups having 1 to 12 carbon atoms, alkoxy groups having 1 to 12 carbon atoms, and groups in which two or more of these groups are combined.
Halogen atoms include fluorine, chlorine, bromine and iodine atoms.
Examples of alkyl groups having 1 to 12 carbon atoms include 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 alkyl group is preferably 1-9, more preferably 1-6, even more preferably 1-4, still more preferably 1-3.
The haloalkyl group having 1 to 12 carbon atoms represents an alkyl group having a halogen atom, and examples thereof include a fluorinated alkyl group, a chlorinated alkyl group, a brominated alkyl group, an iodinated alkyl group and the like. Haloalkyl groups include perfluoroalkyl groups (trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, perfluoropentyl group, perfluorohexyl group, etc.), fluoromethyl group, difluoromethyl group, 2,2 ,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, 3,3,3-trifluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, 4,4 ,4-trifluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, 2,2,3, 3,4,4,5,5,5-nonafluoropentyl group, chloromethyl group, bromomethyl group, iodomethyl group and the like. The haloalkyl group preferably has 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon 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. The alkoxy group preferably has 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
Groups in which two or more types are combined include an alkoxycarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyloxy group having 2 to 13 carbon atoms, and the like.
An alkoxycarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyloxy group having 2 to 13 carbon atoms, or the like is a represents a group.
The alkoxycarbonyl group having 2 to 13 carbon atoms includes methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group and the like, and the alkylcarbonyl group having 2 to 13 carbon atoms includes acetyl group, propionyl group, butyryl group and the like. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include acetyloxy group, propionyloxy group and butyryloxy group.
L ¹ is preferably a single bond or an optionally substituted alkanediyl group having 1 to 4 carbon atoms, more preferably a single bond or an alkanediyl group having 1 to 4 carbon atoms. A bond or an alkanediyl group having 1 to 3 carbon atoms is more preferable, and a single bond or a methylene group is even more preferable.
L ² is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 1 to 3 carbon atoms, and even more preferably a methylene group.
L ³ is preferably an alkanetriyl group having 1 to 4 carbon atoms, more preferably an alkanetriyl group having 1 to 3 carbon atoms, and even more preferably an ethanetriyl group or a propanetriyl group. , ethane-1,1,2-triyl groups are even more preferred.

［式（１ｂ）中、Ｒ^ｂａ１及びＲ^ｂａ２は、それぞれ独立に、水素原子、フッ素原子又はフッ素原子を有する炭素数１～６のアルキル基を表す。
Ｒ^ｂａ３は、フッ素原子又はフッ素原子を有する炭素数１～６のアルキル基を表す。
＊は結合部位を表す。］ The base-labile group of R ¹⁰ contained in R ¹ is a leaving group containing the group represented by R ¹⁰ that leaves when it comes into contact with a base (e.g., 2.38% tetramethylammonium hydroxide aqueous solution). , R ¹ is a group represented by *-R ¹⁰ , *-CO-R ¹⁰ or *-CO-OR ¹⁰ , a hydroxy group is formed on R ¹ and R ¹ is *-L ² - A group represented by CO--O--R ¹⁰ or *--CO--O--L ² --CO--O--R ¹⁰ means a group in which a carboxy group is formed at R ¹ .
As the base-labile group, a group represented by formula (1b) (hereinafter sometimes referred to as "base-labile group (1b)") is preferred.

[In the formula (1b), R ^ba1 and R ^ba2 each independently represent a hydrogen atom, a fluorine atom or a fluorine atom-containing alkyl group having 1 to 6 carbon atoms.
R ^ba3 represents a fluorine atom or a fluorine atom-containing alkyl group having 1 to 6 carbon atoms.
* represents a binding site. ]

［式（Ｒ^２－１）中、Ｌ^３は、置換基を有してもよい炭素数１～６のアルカントリイル基を表す。
Ｒ^ab1及びＲ^ab2は、それぞれ独立に、水素原子、炭素数１～８のアルキル基、もしくは炭素数３～２０の脂環式炭化水素基を表すか、又はＲ^ab1及びＲ^ab2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の脂環式炭化水素基を形成し、該アルキル基及び該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－で置き換わってもよい。
＊は、環Ｗとの結合部位を表す。］
アルキル基及び脂環式炭化水素基としては、上記で挙げた基と同様の基が挙げられる。
基（Ｒ^２－１）としては、例えば、以下で表される基等が挙げられる。＊は、環Ｗとの結合部位を表す。

より具体的には、例えば、以下で表される基等が挙げられる。

Ｒ^１は、＊－ＣＯ－Ｒ^１０、＊－ＣＯ－Ｏ－Ｒ^１０又は＊－Ｌ^２－ＣＯ－Ｏ－Ｒ^１０であることが好ましく、＊－ＣＯ－Ｒ^１０又は＊－ＣＯ－Ｏ－Ｒ^１０であることがより好ましい。
Ｒ^２は、＊－Ｌ^１－Ｏ－Ｒ^１又は式（Ｒ^２－１）で表される基であることが好ましい。 Examples of alkyl groups having fluorine atoms for R ^ba1 , R ^ba2 and R ^ba3 include trifluoromethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 2,2,3,3,3- pentafluoropropyl group, 1-trifluoromethyl-2,2,2-trifluoroethyl group, perfluoropropyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, perfluorobutyl group, 2 , 2,3,3,4,4,5,5,5-nonafluoropentyl group, perfluoropentyl group, perfluorohexyl group and the like. The number of carbon atoms in the alkyl group having a fluorine atom is preferably 1-5, more preferably 1-4, still more preferably 1-3.
R ^ba1 is preferably a hydrogen atom or a fluorine atom.
^Rba2 is preferably a hydrogen atom, a fluorine atom or a trifluoromethyl group.
R ^ba3 is preferably a fluorine atom, a perfluoroalkyl group having 1 to 4 carbon atoms or a perfluoroalkylmethyl group having 2 to 5 carbon atoms, more preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. preferable.
—C(R ^ba1 )(R ^ba2 )(R ^ba3 ) is a perfluoroalkyl group having 1 to 4 carbon atoms, a perfluoroalkylmethyl group having 1 to 4 carbon atoms, or 1-trifluoromethyl-2,2,2- A trifluoroethyl group is preferable, and a perfluoroalkyl group having 1 to 4 carbon atoms or a perfluoroalkylmethyl group having 1 to 4 carbon atoms is more preferable.
R ² may be a group represented by formula (R ² -1) (hereinafter sometimes referred to as "group (R ² -1)").

[In the formula (R ² -1), L ³ represents an optionally substituted alkanetriyl group having 1 to 6 carbon atoms.
R ^ab1 and R ^ab2 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group having 3 to 20 carbon ^{atoms ;} form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded, and —CH ₂ — contained in the alkyl group and the alicyclic hydrocarbon group is —O— or —CO - may be replaced.
* represents a binding site with ring W. ]
Examples of the alkyl group and the alicyclic hydrocarbon group include the same groups as those listed above.
Examples of the group (R ² -1) include the groups represented below. * represents a binding site with ring W.

More specific examples include the groups represented below.

R ¹ is preferably *-CO-R ¹⁰ , *-CO-OR ¹⁰ or *-L ² -CO-O-R ¹⁰ , *-CO-R ¹⁰ or *-CO-O- R ¹⁰ is more preferred.
R ² is preferably *-L ¹ -OR ¹ or a group represented by formula (R ² -1).

［式（３ｂ）中、Ｌ^４は、単結合又は置換基を有してもよい炭素数１～６のアルカンジイル基を表す。
Ｒ^ab1及びＲ^ab2は、それぞれ独立に、水素原子、炭素数１～８のアルキル基、もしくは炭素数３～２０の脂環式炭化水素基を表すか、又はＲ^ab1及びＲ^ab2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の脂環式炭化水素基を形成し、該アルキル基及び該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－で置き換わってもよい。
＊は、環Ｗとの結合部位を表す。］
アルカンジイル基、アルキル基及び脂環式炭化水素基としては、上記で挙げた基と同様の基が挙げられる。
基（３ｂ）としては、例えば、以下で表される基等が挙げられる。＊は、環Ｗとの結合部位を表す。

２つのＲ^３が一緒になってアセタール環構造を有する基を形成している場合、化合物（Ｉ）としては、例えば、以下で表される化合物（Ｉａ）、（Ｉｂ）、（Ｉｃ）、（Ｉｄ）及び（Ｉｅ）等が挙げられる。このうち、化合物（Ｉａ）が好ましい。

より具体的には、例えば、以下で表される化合物等が挙げられる。

Ｒ^３は、好ましくはハロゲン原子、ヒドロキシ基、炭素数１～６のハロアルキル基、炭素数１～６のアルキル基（該アルキル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい）又は２つのＲ^３が一緒になってアセタール環構造を有する基を形成している基であり、より好ましくはハロゲン原子、ヒドロキシ基、炭素数１～４のフッ化アルキル基、炭素数１～４のアルキル基（該アルキル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。）又は２つのＲ^３が一緒になってアセタール環構造を有する基を形成している基であり、さらに好ましくはフッ素原子、ヨウ素原子、ヒドロキシ基、炭素数１～４のフッ化アルキル基、炭素数１～４のアルキル基（該アルキル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい）又は２つのＲ^３が一緒になってアセタール環構造を有する基を形成している基であり、より一層好ましくはフッ素原子、ヨウ素原子、ヒドロキシ基、カルボキシ基、炭素数１～３のペルフルオロアルキル基、炭素数１～３のアルキル基、炭素数１～３のアルコキシ基又は２つのＲ^３が一緒になってアセタール環構造を有する基を形成している基であり、さらに一層好ましくはフッ素原子、ヨウ素原子、ヒドロキシ基、トリフルオロメチル基又は２つのＲ^３が一緒になってアセタール環構造を有する基を形成している基であり、さらにより好ましくはフッ素原子、ヨウ素原子、ヒドロキシ基又は２つのＲ^３が一緒になってアセタール環構造を有する基を形成している基である。
ｍ２は、０～５のいずれかの整数が好ましく、１～５のいずれかの整数がより好ましく、１～４のいずれかの整数がさらに好ましく、１～３のいずれかの整数がより一層好ましく、１又は２がさらに一層好ましい。
ｍ３は、０～５のいずれかの整数が好ましく、０～４のいずれかの整数がより好ましく、０～３のいずれかの整数がさらに好ましく、１～３のいずれかの整数がより一層好ましく、２又は３がさらに一層好ましい。 The halogen atom for R3 includes a fluorine atom ^, a chlorine atom, a bromine atom, an iodine atom and the like.
The haloalkyl group having 1 to 12 carbon atoms for R ³ represents an alkyl group having 1 to 12 carbon atoms having a halogen atom, a fluorinated alkyl group having 1 to 12 carbon atoms, a chlorinated alkyl group having 1 to 12 carbon atoms, Examples thereof include alkyl bromide groups having 1 to 12 carbon atoms and alkyl iodide groups having 1 to 12 carbon atoms. Haloalkyl groups include perfluoroalkyl groups having 1 to 12 carbon atoms (trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, perfluoropentyl group, perfluorohexyl group, etc.), fluoromethyl group, difluoro methyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, 3,3,3-trifluoropropyl group, 2,2,3,3,3-pentafluoro propyl group, 4,4,4-trifluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, chloromethyl group, bromomethyl group, iodomethyl group and the like. The haloalkyl group preferably has 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
Examples of the alkyl group having 1 to 12 carbon atoms for R ³ include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group, nonyl group, and the like. An alkyl group is mentioned. The number of carbon atoms in the alkyl group is preferably 1-9, more preferably 1-6, even more preferably 1-4, still more preferably 1-3.
When —CH ₂ — contained in the alkyl group of R ³ is replaced with —O— or —CO—, the number of carbon atoms before the replacement is taken as the total number of carbon atoms in the alkyl group. Examples of substituted groups include a hydroxy group (a group in which —CH ₂ — contained in a methyl group is replaced by —O—), a carboxy group (a group in which —CH ₂ —CH ₂ — contained in an ethyl group is replaced by —O -CO-), alkoxy group (group in which -CH ₂ - at any position in the alkyl group is replaced with -O-), alkoxycarbonyl group (any position in the alkyl group of —CH ₂ —CH ₂ — is replaced with —O—CO—), an alkylcarbonyl group (a group in which —CH ₂ — at any position in an alkyl group is replaced with —CO—), Alkylcarbonyloxy groups (groups in which —CH ₂ —CH ₂ — at arbitrary positions in an alkyl group are replaced with —CO—O—), groups in which two or more of these groups are combined, and the like. be done.
The alkoxy group includes alkoxy groups having 1 to 11 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy and hexyloxy groups. The number of carbon atoms in the alkoxy group is preferably 1-6, more preferably 1-4, still more preferably 1-3.
An alkoxycarbonyl group, an alkylcarbonyl group and an alkylcarbonyloxy group represent groups in which a carbonyl group or a carbonyloxy group is bonded to the above alkyl group or alkoxy group.
The alkoxycarbonyl group includes alkoxycarbonyl groups having 2 to 11 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl and butoxycarbonyl groups. The alkylcarbonyl group includes alkylcarbonyl groups having 2 to 12 carbon atoms, such as acetyl group, propionyl group and butyryl group. The alkylcarbonyloxy group includes alkylcarbonyloxy groups having 2 to 11 carbon atoms, such as acetyloxy, propionyloxy and butyryloxy groups. The alkoxycarbonyl group preferably has 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms. The number of carbon atoms in the alkylcarbonyl group is preferably 2-6, more preferably 2-4, still more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2-6, more preferably 2-4, still more preferably 2 or 3.
When two R ³ 's together form a group having an acetal ring structure, such a group includes, for example, a group represented by formula (3b) (hereinafter sometimes referred to as "group (3b) ”) and the like.

[In the formula (3b), L ⁴ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms which may have a substituent.
R ^ab1 and R ^ab2 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group having 3 to 20 carbon ^{atoms ;} form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded, and —CH ₂ — contained in the alkyl group and the alicyclic hydrocarbon group is —O— or —CO - may be replaced.
* represents a binding site with ring W. ]
The alkanediyl group, the alkyl group and the alicyclic hydrocarbon group include the same groups as those listed above.
Examples of the group (3b) include the groups represented below. * represents a binding site with ring W.

When two R ^3s together form a group having an acetal ring structure, examples of compound (I) include compounds (Ia), (Ib), (Ic), ( Id) and (Ie). Among these, compound (Ia) is preferred.

More specific examples include the compounds represented below.

R ³ is preferably a halogen atom, a hydroxy group, a haloalkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 6 carbon atoms (where —CH ₂ — contained in the alkyl group is —O— or —CO— or a group in which two R ^3s together form a group having an acetal ring structure, more preferably a halogen atom, a hydroxy group, or a fluorinated alkyl group having 1 to 4 carbon atoms. , an alkyl group having 1 to 4 carbon atoms (-CH ₂ - contained in the alkyl group may be replaced with -O- or -CO-), or an acetal ring structure in which two R ³ are combined more preferably a fluorine atom, an iodine atom, a hydroxy group, a fluorinated alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms (included in the alkyl group —CH ₂ — may be replaced with —O— or —CO—) or two R ³ together form a group having an acetal ring structure, more preferably fluorine atom, iodine atom, hydroxy group, carboxy group, perfluoroalkyl group having 1 to 3 carbon atoms, alkyl group having 1 to 3 carbon atoms, alkoxy group having 1 to 3 carbon atoms, or an acetal ring in which two R ³ are combined a group forming a group having a structure, more preferably a fluorine atom, an iodine atom, a hydroxy group, a trifluoromethyl group or two R ³ together forming a group having an acetal ring structure and more preferably a fluorine atom, an iodine atom, a hydroxy group or a group in which ^two R3's together form a group having an acetal ring structure.
m2 is preferably an integer of 0 to 5, more preferably an integer of 1 to 5, more preferably an integer of 1 to 4, and even more preferably an integer of 1 to 3 , 1 or 2 are even more preferred.
m3 is preferably an integer of 0 to 5, more preferably an integer of 0 to 4, more preferably an integer of 0 to 3, and even more preferably an integer of 1 to 3 , 2 or 3 are even more preferred.

Compound (I) includes compounds represented by the following formula.

The content of compound (I) is usually 0.001 to 20% by mass, preferably 0.005 to 15% by mass, more preferably 0.01 to 10% by mass, based on the solid content of the resist composition. .

<Resin (A)>
The resin (A) contains 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, a structural unit having a halogen atom described later (hereinafter sometimes referred to as "structural unit (a4)"), a structural unit having a non-eliminating hydrocarbon group described later (hereinafter referred to as "structural unit (a5)" in some cases) and other structural units derived from monomers known in the art.

［式（１）中、Ｒ^ａ１、Ｒ^ａ２及びＲ^ａ３は、それぞれ独立に、炭素数１～８のアルキル基、炭素数２～８のアルケニル基、炭素数３～２０の脂環式炭化水素基、炭素数６～１８の芳香族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の非芳香族炭化水素環を形成する。
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。
＊は結合部位を表す。］

［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の複素環を形成し、該炭化水素基及び該複素環に含まれる－ＣＨ_２－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。
＊は結合部位を表す。］ <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 a group represented by formula (1) (hereinafter also referred to as group (1)) and/or a group represented by formula (2) (hereinafter referred to as group (2 )) is preferable.

[In the formula (1), R ^a1 , R ^a2 and R ^a3 are each independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon having 3 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms or a combination thereof, or R ^a1 and R ^a2 are bonded to each other and together with the carbon atom to which they are bonded, a non-aromatic hydrocarbon group having 3 to 20 carbon atoms. Form a hydrogen ring.
ma and na each independently represent 0 or 1, and at least one of ma and na represents 1;
* represents a binding site. ]

[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 heterocyclic ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and —CH ₂ contained in the hydrocarbon group and the heterocyclic ring - may be replaced by -O- or -S-.
X represents an oxygen atom or a sulfur atom.
na' represents 0 or 1;
* represents a binding site. ]

Ｒ^ａ１、Ｒ^ａ２及びＲ^ａ３における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、ビフェニル基、フェナントリル基等のアリール基が挙げられる。
組み合わせた基としては、上述したアルキル基と脂環式炭化水素基とを組み合わせた基（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のアルキルシクロアルキル基又はシクロアルキルアルキル基）、ベンジル基等のアラルキル基、アルキル基を有する芳香族炭化水素基（ｐ－メチルフェニル基、ｐ－ｔｅｒｔ－ブチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、２，６－ジエチルフェニル基、２－メチル－６－エチルフェニル基等）、脂環式炭化水素基を有する芳香族炭化水素基（ｐ－シクロヘキシルフェニル基、ｐ－アダマンチルフェニル基等）、フェニルシクロヘキシル基等のアリール－シクロアルキ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が互いに結合して非芳香族炭化水素環を形成する場合の－Ｃ（Ｒ^a1）（Ｒ^a2）（Ｒ^a3）としては、下記の環が挙げられる。非芳香族炭化水素環は、好ましくは炭素数３～１２である。＊は－Ｏ－との結合部位を表す。

Examples of alkyl groups for R ^a1 , R ^a2 and R ^a3 include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group and octyl group.
The alkenyl group for R ^a1 , R ^a2 and R ^a3 includes ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, tert-butenyl, pentenyl, hexenyl, heptenyl, octenyl, isooctenyl, A nonenyl group is mentioned.
The alicyclic hydrocarbon groups for R ^a1 , R ^a2 and R ^a3 may be either monocyclic or polycyclic. The monocyclic alicyclic hydrocarbon group includes cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bonding site). The alicyclic hydrocarbon groups of R ^a1 , R ^a2 and R ^a3 preferably have 3 to 16 carbon atoms.

Examples of aromatic hydrocarbon groups for R ^a1 , R ^a2 and R ^a3 include aryl groups such as phenyl, naphthyl, anthryl, biphenyl and phenanthryl groups.
Examples of the combined group include groups obtained by combining the above alkyl groups and alicyclic hydrocarbon groups (e.g., methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyl a dimethyl group, an alkylcycloalkyl group such as a norbornylethyl group or a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p- cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like.
Preferably, ma is 0 and na is 1.
-C(R ^a1 )(R ^a2 )(R ^a3 ) when R ^a1 and R ^a2 combine to form a non-aromatic hydrocarbon ring include the following rings. The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * represents a binding site 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 hydrocarbon groups for R ^a1′ , R ^a2′ and R ^a3′ include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, groups formed by combining these groups, and the like.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same groups as those listed for R ^a1 , R ^a2 and R ^a3 .
Aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl groups.
Examples of the combined group include groups obtained by combining the above alkyl groups and alicyclic hydrocarbon groups (e.g., methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyl a dimethyl group, an alkylcycloalkyl group such as a norbornylethyl group or a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p- cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like.
When R ^a2′ and R ^a3′ are bonded to each other to form a heterocyclic ring together with the carbon atom to which they are bonded and X, —C(R ^a1′ )(R ^a2′ )—X—R ^a3′ is represented by the following ring. * represents the binding site.

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

Group (1) includes the following groups.
A group in which R ^a1 , R ^a2 and R ^a3 in formula (1) are alkyl groups, ma=0 and na=1. The group is preferably a tert-butoxycarbonyl group.
In formula (1), R ^a1 and R ^a2 form an adamantyl group together with the carbon atoms to which they are attached, R ^a3 is an alkyl group, ma = 0 and na = 1. .
A group in which R ^a1 and R ^a2 are each independently an alkyl group, R ^a3 is an adamantyl group, ma=0 and na=1 in formula (1).
Specific examples of the group (1) include the following groups. * represents a binding site.

Specific examples of group (2) include the following groups. * represents a binding site.

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－との結合部位を表す。
Ｒ^a01、Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、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。
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、炭素数６～１８の芳香族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２～８のアルケニル基、炭素数３～１８の脂環式炭化水素基、炭素数６～１８の芳香族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。］ As a structural unit derived from a (meth)acrylic monomer having a group (1), a structural unit represented by formula (a1-0) (hereinafter sometimes referred to as structural unit (a1-0)), 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 structural unit (a1-2) There is a case.) is mentioned. Preferably, it is at least one structural unit selected from the group consisting of structural unit (a1-0), structural unit (a1-1) and structural unit (a1-2), more preferably structural unit (a1- 1) and at least one or two structural units selected from the group consisting of structural units (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 the binding site with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom, a halogen atom or an optionally halogenated alkyl group having 1 to 6 carbon atoms.
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, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or Represents a combined group.
R ^a6 and R ^a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic group having 6 to 18 carbon atoms. It represents a hydrocarbon group or a group formed by combining these groups.
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 a hydrogen atom or a methyl group, more preferably a methyl group.
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 include alkyl groups, ^alkenyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups and groups in which these groups are combined. The same groups as those mentioned for R ^a2 and R ^a3 can be mentioned.
The alkyl group for R ^a02 , R ^a03 and R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, still more preferably a methyl group.
The alkyl group for R ^a6 and R ^a7 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group or a t-butyl group, still more preferably an ethyl group or an isopropyl group. or a t-butyl group.
The alkenyl group for R ^a6 and R ^a7 is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably an ethenyl group, propenyl group, isopropenyl group or butenyl group.
The alicyclic hydrocarbon groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 preferably have 5 to 12 carbon atoms, more preferably 5 to 10 carbon atoms.
The aromatic hydrocarbon groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 preferably have 6 to 12 carbon atoms, more preferably 6 to 10 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.
It is preferable that the combined group of an alkyl group and an aromatic hydrocarbon group have a total carbon number of 18 or less.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably methyl group, ethyl group, phenyl group or naphthyl group.
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.
R ^a6 and R ^a7 are each independently preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group , ethyl, isopropyl, t-butyl, ethenyl, phenyl or naphthyl, more preferably ethyl, isopropyl, t-butyl, ethenyl or phenyl.
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 (a1-0-18) and R ^a01 in the structural unit (a1-0) Structural units in which the corresponding methyl group is replaced with a hydrogen atom, a halogen atom, a haloalkyl group (an alkyl group having a halogen atom) or other alkyl groups, and examples of formulas (a1-0-1) to (a1-0- 10), a structural unit represented by formula (a1-0-13) or formula (a1-0-14) is preferred.

Examples of structural units (a1-1) include structural units derived from monomers described in JP-A-2010-204646. Among them, a structural unit represented by any one of formulas (a1-1-1) to (a1-1-7) and a methyl group corresponding to R ^a4 in structural unit (a1-1) is a hydrogen atom or a halogen atom. , a haloalkyl group or other alkyl group is preferred, and a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) is more preferred.

The structural unit (a1-2) corresponds to a structural unit represented by any one of formulas (a1-2-1) to (a1-2-14) and R ^a5 in the structural unit (a1-2). Structural units in which a methyl group is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group include formula (a1-2-2), formula (a1-2-5), formula (a1-2-6 ) and structural units represented by any one of formulas (a1-2-10) to (a1-2-14) are preferred.

When the resin (A) contains the structural unit (a1-0), its content is usually 5 to 80 mol%, preferably 5 to 75 mol%, based on the total structural units of the resin (A). Yes, more preferably 10 to 70 mol %.
When the resin (A) contains the structural unit (a1-1) and/or the structural unit (a1-2), the total content of these is usually 10 to 90 mol with respect to the total structural units of the resin (A). %, preferably 15 to 85 mol %, more preferably 20 to 80 mol %, still more preferably 20 to 75 mol %, still more preferably 20 to 70 mol %.

［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いてもよい炭素数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２～１２のアルコキシアルキル基、炭素数２～１２のアルコキシアルコキシ基、炭素数２～４のアルキルカルボニル基、炭素数２～４のアルキルカルボニルオキシ基、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^a30は、単結合又は^＊－Ｘ^a31－（Ａ^a32－Ｘ^a32）_nc－を表し、＊は－Ｒ^a32が結合する炭素原子との結合部位を表す。
Ａ^a32は、炭素数１～６のアルカンジイル基を表す。
Ｘ^a31及びＸ^a32は、それぞれ独立に、－Ｏ－、－ＣＯ－Ｏ－又は－Ｏ－ＣＯ－を表す。
ｎｃは、０又は１を表す。
ｌａは０～４のいずれかの整数を表す。ｌａが２以上のいずれかの整数である場合、複数のＲ^a33は互いに同一でも異なっていてもよい。
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。］ Structural units having group (2) in structural unit (a1) include structural units represented by formula (a1-4) (hereinafter sometimes referred to as “structural unit (a1-4)”). .

[In 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 alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, and a carbon number It represents an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group.
A ^a30 represents a single bond or ^* -X ^a31 -(A ^a32 -X ^a32 ) _nc -, and * represents a bonding site with the carbon atom to which -R ^a32 is bonded.
A ^a32 represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a31 and X ^a32 each independently represent -O-, -CO-O- or -O-CO-.
nc represents 0 or 1;
la represents an integer of 0 to 4; When la is any integer of 2 or more, the 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- or -S- may be substituted. ]

Halogen atoms in 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 for R ^a32 include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2, 3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group and perfluoro A hexyl group is mentioned.
R ^a32 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 alkyl groups for R ^a33 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-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, and even more preferably a methyl group.
The alkoxy group for R ^a33 includes methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, tert-butoxy, pentyloxy and hexyloxy groups. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and still more preferably a methoxy group.
Alkoxyalkyl groups for R ^a33 include methoxymethyl, ethoxyethyl, propoxymethyl, isopropoxymethyl, butoxymethyl, sec-butoxymethyl and tert-butoxymethyl groups. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, even more preferably a methoxymethyl group.
The alkoxyalkoxy group for R ^a33 includes a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group and a tert-butoxymethoxy group. mentioned. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group.
The alkylcarbonyl group for R ^a33 includes an acetyl group, a propionyl group and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group.
The alkylcarbonyloxy group for R ^a33 includes an acetyloxy group, a propionyloxy group and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably an acetyloxy group.
R ^a33 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or an alkoxyalkoxy group having 2 to 8 carbon atoms, a fluorine atom, an iodine atom, a hydroxy group, a methyl A group, a methoxy group, an ethoxy group, an ethoxyethoxy group or an ethoxymethoxy group is more preferable, and a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group is more preferable.

*-X ^a31 -(A ^a32 -X ^a32 ) _nc - includes *-O-, *-CO-O-, *-O-CO-, *-CO-O-A ^a32 -CO-O-, *-O-CO- ^Aa32 -O-, *-O- ^Aa32 -CO-O-, *-CO-O- ^Aa32 -O-CO-, *-O-CO- ^Aa32 -O-CO -, are included. Among them, *-CO-O-, *-CO-O-A ^a32 -CO-O- or *-O-A ^a32 -CO-O- is preferred.

Alkanediyl group for A ^a32 includes methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group and 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 and 2-methylbutane-1,4-diyl group.
A ^a32 is preferably a methylene group or an ethylene group.

A ^a30 is preferably a single bond, *-CO-O- or *-CO-O-A ^a32 -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.

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、ビフェニル基、フェナントリル基等のアリール基が挙げられる。
組み合わせた基としては、上述したアルキル基と脂環式炭化水素基とを組み合わせた基（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のアルキルシクロアルキル基又はシクロアルキルアルキル基）、ベンジル基等のアラルキル基、アルキル基を有する芳香族炭化水素基（ｐ－メチルフェニル基、ｐ－ｔｅｒｔ－ブチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、２，６－ジエチルフェニル基、２－メチル－６－エチルフェニル基等）、脂環式炭化水素基を有する芳香族炭化水素基（ｐ－シクロヘキシルフェニル基、ｐ－アダマンチルフェニル基等）、フェニルシクロヘキシル基等のアリール－シクロアルキル基等が挙げられる。特に、Ｒ^a36としては、炭素数１～１８のアルキル基、炭素数３～１８の脂環式炭化水素基、炭素数６～１８の芳香族炭化水素基又はこれらを組み合わせることにより形成される基が挙げられる。 la is preferably 0, 1 or 2, more preferably 0 or 1, and still more preferably 0.
The hydrocarbon groups for R ^a34 , R ^a35 and R ^a36 include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and combinations thereof.
Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl groups.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic. The monocyclic alicyclic hydrocarbon group includes cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bonding site).

Aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl groups.
Examples of the combined group include groups obtained by combining the above alkyl groups and alicyclic hydrocarbon groups (e.g., methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyl a dimethyl group, an alkylcycloalkyl group such as a norbornylethyl group or a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p- cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like. In particular, R ^a36 is 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. are mentioned.

R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, 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 hydrocarbon group having 3 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and 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.
--OC(R ^a34 )(R ^a35 )-OR ^a36 in the structural unit (a1-4) is eliminated upon contact with an acid (eg, p-toluenesulfonic acid) to form a hydroxy group.
—OC(R ^a34 )(R ^a35 )—OR ^a36 preferably bonds to the o-position or p-position of the benzene ring, more preferably to the p-position.

Examples of structural units (a1-4) include structural units derived from monomers described in JP-A-2010-204646. Preferably, the hydrogen atom corresponding to R ^a32 in structural units and structural units (a1-4) represented by formulas (a1-4-1) to (a1-4-24) is a halogen atom or a haloalkyl group. or a structural unit substituted with an alkyl group, more preferably formula (a1-4-1) ~ formula (a1-4-5), formula (a1-4-10), formula (a1-4-13 ), formula (a1-4-14), formula (a1-4-19), and formula (a1-4-20).

When the resin (A) contains the structural unit (a1-4), the content thereof is preferably 3 to 80 mol%, preferably 5 to 75 mol%, based on the total of all structural units of the resin (A). It is more preferably 7 to 70 mol %, even more preferably 7 to 65 mol %, and particularly preferably 10 to 60 mol %.

式（ａ１－５）中、
Ｒ^a8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、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との結合部位を表す。
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。 Structural units derived from (meth)acrylic monomers having group (2) include structural units represented by formula (a1-5) (hereinafter sometimes referred to as “structural unit (a1-5)”). be done.

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 binding site with L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent -O- or -S-.
s1 represents an integer of 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 trifluoro A methyl group is mentioned.
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 structural units (a1-5) include structural units derived from 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) contains the structural unit (a1-5), its content is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, based on the total structural units of the resin (A). , more preferably 5 to 40 mol %, and even more preferably 5 to 30 mol %.

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

When the resin (A) contains structural units such as the above (a1-3-1) to (a1-3-7), the content is 10 to 10 to the total structural units of the resin (A). 95 mol % is preferred, 15 to 90 mol % is more preferred, 20 to 85 mol % is even more preferred, 20 to 70 mol % is even more preferred, and 20 to 60 mol % is particularly preferred.

樹脂（Ａ）が上記、（ａ１－６－１）～（ａ１－６－３）のような構造単位を含む場合、その含有率は、樹脂（Ａ）の全構造単位に対して、１０～６０モル％が好ましく、１５～５５モル％がより好ましく、２０～５０モル％がさらに好ましく、２０～４５モル％がさらにより好ましく、２０～４０モル％が特に好ましい。 The structural unit (a1) also includes the following structural units.

When the resin (A) contains structural units such as the above (a1-6-1) to (a1-6-3), the content is 10 to 10 to the total structural units of the resin (A). 60 mol % is preferred, 15 to 55 mol % is more preferred, 20 to 50 mol % is even more preferred, 20 to 45 mol % is even more preferred, and 20 to 40 mol % is particularly 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.
The structural unit (s) preferably has a hydroxy group or a lactone ring. 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 containing 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) , a structural unit (a2) having a phenolic hydroxy group is preferable, and it is more preferable to use a structural unit (a2-A) described later. 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, and more preferably a structural unit (a2-1) described later. preferable. 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いてもよい炭素数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２～１２のアルコキシアルキル基、炭素数２～１２のアルコキシアルコキシ基、炭素数２～４のアルキルカルボニル基、炭素数２～４のアルキルカルボニルオキシ基、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）_nb－を表し、＊は－Ｒ^a50が結合する炭素原子との結合部位を表す。
Ａ^a52は、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。
ｎｂ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以上のいずれかの整数である場合、複数のＲ^a51は互いに同一でも異なっていてもよい。］ Structural units having a phenolic hydroxy group in structural units (a2) 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 alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, It represents an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group.
A ^a50 represents a single bond or *-X ^a51 -(A ^a52 -X ^a52 ) _nb -, and * represents a bonding site with the carbon atom to which -R ^a50 bonds.
A ^a52 represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 each independently represent -O-, -CO-O- or -O-CO-.
nb represents 0 or 1;
mb represents an integer from 0 to 4; When mb is any integer of 2 or more, multiple R ^a51 may be the same or different. ]

Halogen atoms in R ^a50 and R ^a51 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 a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2, 3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group and perfluoro A hexyl group is mentioned.
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 alkyl groups for R ^a51 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-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, and even more preferably a methyl group.
Alkoxy groups for R ^a51 include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy and tert-butoxy groups. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and still more preferably a methoxy group.
Alkoxyalkyl groups for R ^a51 include methoxymethyl, ethoxyethyl, propoxymethyl, isopropoxymethyl, butoxymethyl, sec-butoxymethyl and tert-butoxymethyl groups. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, even more preferably a methoxymethyl group.
The alkoxyalkoxy group for R ^a51 includes a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group and a tert-butoxymethoxy group. mentioned. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group.
The alkylcarbonyl group for R ^a51 includes an acetyl group, a propionyl group and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group.
The alkylcarbonyloxy group for R ^a51 includes an acetyloxy group, a propionyloxy group and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably an acetyloxy group.
R ^a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or an alkoxyalkoxy group having 2 to 8 carbon atoms, a fluorine atom, an iodine atom, a hydroxy group, a methyl A group, a methoxy group, an ethoxy group, an ethoxyethoxy group or an ethoxymethoxy group is more preferable, and a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group is more preferable.

*-X ^a51 -(A ^a52 -X ^a52 ) _nb - 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- or * ^{-OA a52} -CO-O- is preferred.

The alkanediyl group for A ^a52 includes methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, and 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 and 2-methylbutane-1,4-diyl group.
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 still more preferably 0.
The hydroxy group is preferably attached to the m-position or p-position of the benzene ring, and more preferably attached to the m-position. When the phenyl group has two or more hydroxy groups, the two hydroxy groups are preferably bonded to the m- and p-positions, respectively.

Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577.
The structural unit (a2-A) includes structural units represented by formulas (a2-2-1) to (a2-2-24) and formulas (a2-2-1) to (a2-2-24). ) in which the methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. Structural unit (a2-A) includes structural units represented by formulas (a2-2-1) to (a2-2-4), structural units represented by formula (a2-2-6), and structural units represented by formula ( a2-2-8), structural units represented by formulas (a2-2-12) to (a2-2-18) and formulas (a2-2-1) to (a2- 2-4), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), and formulas (a2-2-12) to In the structural unit represented by formula (a2-2-18), it is preferably a structural unit in which the methyl group corresponding to R ^a50 in structural unit (a2-A) is replaced with a hydrogen atom. -3), structural unit represented by formula (a2-2-4), structural unit represented by formula (a2-2-8), formula (a2-2-12) to formula A structural unit represented by (a2-2-14), a structural unit represented by formula (a2-2-18) and a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2- 4), structural units represented by formula (a2-2-8), structural units represented by formulas (a2-2-12) to (a2-2-14), and formula ( a2-2-18), the structural unit is more preferably a structural unit in which the methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom, and the structural unit represented by the formula (a2-2- 3), a structural unit represented by formula (a2-2-4), a structural unit represented by formula (a2-2-8) and a structural unit represented by formula (a2-2-3) the structural unit represented by formula (a2-2-4), the structural unit represented by formula (a2-2-8), the methyl group corresponding to R ^a50 in structural unit (a2-A) is more preferably a structural unit in which is replaced with a hydrogen atom.

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%, more preferably It is 10 to 70 mol %, more preferably 15 to 65 mol %, still more preferably 20 to 65 mol %.
The structural unit (a2-A) can be included in the resin (A), for example, by polymerizing the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Also, the structural unit (a2-A) can be included in the resin (A) by polymerizing with acetoxystyrene or the like and then treating with an alkali such as tetramethylammonium hydroxide.

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－との結合部位を表す。
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。 A structural unit having an alcoholic hydroxy group in the structural unit (a2) includes a structural unit 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 bonding site 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 represents an integer of 1 to 4) , and 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 the structural unit (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 formula (a2-1-1) or formula (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 1 to 20 mol %, still more preferably 1 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. Preferable examples include a γ-butyrolactone ring, an adamantanelactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)).

［式（ａ３－１）、式（ａ３－２）、式（ａ３－３）及び式（ａ３－４）中、
Ｌ^ａ４、Ｌ^ａ５及びＬ^ａ６は、それぞれ独立に、－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部位を表す。
Ｒ^ａ１８、Ｒ^ａ１９及びＲ^ａ２０は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^ａ２４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。
Ｘ^ａ３は、－ＣＨ_２－又は酸素原子を表す。
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、それぞれ独立に、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は互いに同一でも異なっていてもよい。］ 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 are each independently represented by —O— or *—O—(CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7); represents a group.
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 bonding site with a carbonyl group.
R ^a18 , R ^a19 and R ^a20 each independently represent a hydrogen atom or a methyl group.
R ^a24 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
X ^a3 represents —CH ₂ — or an oxygen atom.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
R ^a22 , R ^a23 and R ^a25 each independently 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. ]

Examples of the aliphatic hydrocarbon group for R ^a21 , R ^a22 , R ^a23 and R ^a25 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group and tert-butyl group. be done.
Halogen atoms in R ^a24 include fluorine, chlorine, bromine and iodine atoms.
Examples of the alkyl group for R ^a24 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group, preferably having 1 to 4 carbon atoms. and 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 are included.

The alkanediyl group for L ^a8 and L ^a9 includes 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—(CH ₂ ) _k3 —CO—O—, k3 is an integer of 1 to 4, 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—.
w1 is preferably an integer from 0 to 2, more preferably 0 or 1.
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 any one of formulas (a3-3-2) and formulas (a3-4-1) to (a3-4-12), and in said structural unit, formula (a3-1 ) to R ^a19 , R ^a20 and R ^a24 in formulas ( ^a3-4 ) are preferably structural units in which methyl groups are replaced with hydrogen atoms.

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) or 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）中、
Ｒ⁴¹は、水素原子又はメチル基を表す。
Ｒ⁴²は、炭素数１～２４のハロゲン原子を有する飽和炭化水素基を表し、該飽和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。］
Ｒ⁴²で表される飽和炭化水素基は、鎖式飽和炭化水素基及び単環又は多環の脂環式飽和炭化水素基、並びに、これらを組み合わせることにより形成される基等が挙げられる。 <Structural unit (a4)>
Structural units (a4) include the following structural units.

[In formula (a4),
R ⁴¹ represents a hydrogen atom or a methyl group.
R ⁴² represents a saturated hydrocarbon group having a halogen atom of 1 to 24 carbon atoms, and --CH ₂ -- contained in the saturated hydrocarbon group may be replaced with --O-- or --CO--. ]
The saturated hydrocarbon group represented by R ⁴² includes chain saturated hydrocarbon groups, monocyclic or polycyclic saturated alicyclic hydrocarbon groups, and groups formed by combining these groups.

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の脂環式飽和炭化水素基とを組み合わせることにより形成される基が挙げられ、－アルカンジイル基－脂環式飽和炭化水素基、－脂環式飽和炭化水素基－アルキル基、－アルカンジイル基－脂環式飽和炭化水素基－アルキル基等が挙げられる。 Chain saturated hydrocarbon groups include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group and octadecyl group. are mentioned.
The monocyclic or polycyclic saturated alicyclic hydrocarbon group includes cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group and the following polycyclic alicyclic saturated hydrocarbon groups such as groups (* represents a bonding site).

Groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic saturated hydrocarbon groups, and -alkanediyl groups Examples include - alicyclic saturated hydrocarbon group, - alicyclic saturated hydrocarbon group - alkyl group, - alkanediyl group - alicyclic saturated hydrocarbon group - alkyl group, and the like.

［式（ａ４－０）中、
Ｒ⁵⁴は、水素原子又はメチル基を表す。
Ｌ^4ａは、単結合又は炭素数１～４のアルカンジイル基を表す。
Ｌ^3ａ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。
Ｒ⁶⁴は、水素原子又はフッ素原子を表す。］ The structural unit (a4) includes a structural unit represented by formula (a4-0), a structural unit represented by formula (a4-1), and a structural unit represented by formula (a4-4). .

[In the formula (a4-0),
^R54 represents a hydrogen atom or a methyl group.
L ^4a represents a single bond or an alkanediyl group having 1 to 4 carbon atoms.
L ^3a represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
^R64 represents a hydrogen atom or a fluorine atom. ]

The alkanediyl group for L ^4a includes linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, ethane-1,1-diyl, branched alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group; be done.

The perfluoroalkanediyl group for L ^3a includes a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, and a perfluoropropane-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 ^3a includes a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantanediyl group, and the like.

L ^4a is preferably a single bond, a methylene group or an ethylene group, more preferably a single bond or a methylene group.
L ^3a 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 the methyl group corresponding to R ⁵⁴ in the structural unit (a4-0) 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、置換基としてハロゲン原子（好ましくはフッ素原子）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２価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２価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。〕
＊は結合部位であり、右側の＊が－Ｏ－ＣＯ－Ｒ^a42との結合部位である。］

[In formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group is replaced with —O— or —CO— may
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 halogen atom (preferably 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 divalent saturated hydrocarbon group having 1 to 5 carbon atoms.
A ^a43 represents a single bond or an optionally substituted C 1-5 divalent saturated hydrocarbon group.
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 binding site, and * on the right side is a binding site with --O--CO--R ^a42 . ]

Examples of saturated hydrocarbon groups for R ^a42 include chain saturated hydrocarbon groups, monocyclic or polycyclic saturated alicyclic hydrocarbon groups, groups formed by combining these groups, and the like.

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の脂環式飽和炭化水素基とを組み合わせることにより形成される基が挙げられ、－アルカンジイル基－脂環式飽和炭化水素基、－脂環式飽和炭化水素基－アルキル基、－アルカンジイル基－脂環式飽和炭化水素基－アルキル基等が挙げられる。 Chain saturated hydrocarbon groups include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group and octadecyl group. etc.
The monocyclic or polycyclic saturated alicyclic hydrocarbon group includes cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group and the following polycyclic alicyclic saturated hydrocarbon groups such as groups (* represents a bonding site).

Groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic saturated hydrocarbon groups, and -alkanediyl groups Examples include - alicyclic saturated hydrocarbon group, - alicyclic saturated hydrocarbon group - alkyl group, - alkanediyl group - alicyclic saturated hydrocarbon group - alkyl group, and the like.

［式（ａ－ｇ３）中、
Ｘ^a43は、酸素原子、カルボニル基、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－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の飽和炭化水素基を表す。
＊はＲ^a42との結合部位を表す。］
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の飽和炭化水素基を表す。 Examples of substituents possessed by R ^a42 include at least one selected from the group consisting of halogen atoms and groups represented by formulas (a-g3). 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, *--O--CO-- or *--CO--O--.
A ^a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
* represents the binding site with ^Ra42 . ]
However, in R ^a42 -X ^a43 -A ^a45 , when R ^a42 does not have a halogen atom, A ^a45 represents a C 1-17 saturated hydrocarbon group having at least one halogen atom.

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の脂環式炭化水素基とを組み合わせることにより形成される基が挙げられ、－アルカンジイル基－脂環式炭化水素基、－脂環式炭化水素基－アルキル基、－アルカンジイル基－脂環式炭化水素基－アルキル基等が挙げられる。 The saturated hydrocarbon groups for A ^a45 include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl Alkyl groups such as groups;
Monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups ) and other polycyclic alicyclic hydrocarbon groups.

Groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, and -alkanediyl groups- Alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, -alkanediyl group-alicyclic hydrocarbon group-alkyl group and the like.

R ^a42 is preferably a saturated hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and/or a saturated hydrocarbon group having a group represented by formula (a-g3).
When R ^a42 is a saturated hydrocarbon group having a halogen atom, it is preferably a saturated hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, still more preferably having 1 to 1 carbon atoms. A perfluoroalkyl group having 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 a saturated hydrocarbon group having a group represented by formula (a-g3), the total carbon number of R ^a42 including the number of carbon atoms contained in the group represented by formula (a-g3) The number 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２価の飽和炭化水素基を表す。
Ｘ^a44は、＊＊－Ｏ－ＣＯ－又は＊＊－ＣＯ－Ｏ－を表す（＊＊はＡ^a46との結合部位を表す。）。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数１～１７の飽和炭化水素基を表す。
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部位を表す。］ When R ^a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), R ^a42 is more preferably a group represented by formula (a-g2).

[In the formula (a-g2),
A ^a46 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents **-O-CO- or **-CO-O- (** represents a binding site with A ^a46 ).
A ^a47 represents a saturated 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 bonding site with a carbonyl group. ]

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

A preferred structure of the group represented by formula (a-g2) is the following structure (* is a bonding site with a carbonyl group).

Alkanediyl group for A ^a41 includes methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, 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 represented by 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 divalent saturated hydrocarbon groups represented by A ^a42 , A ^a43 and A ^a44 in the group represented by the formula (a-g1) include linear or branched alkanediyl groups and monocyclic divalent alicyclic A saturated hydrocarbon group, a divalent saturated hydrocarbon group formed by combining an alkanediyl group and a divalent saturated alicyclic hydrocarbon group, and the like are included. 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 divalent saturated hydrocarbon groups represented by 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.

Among the groups represented by the formula (a-g1), examples of groups in which X ^a42 is -O-, -CO-, -CO-O- or -O-CO- include the following groups. In the following examples, * and ** each represent a binding site, and ** is the binding site with --O--CO--R ^a42 .

As the structural unit represented by formula (a4-1), the following structural units and the methyl group corresponding to R ^a41 in the structural unit represented by formula (a4-1) in the following structural units is replaced with a hydrogen atom. Structural units replaced are included.

［式（ａ４－２）中、
Ｒ^f5は、水素原子又はメチル基を表す。
Ｌ⁴⁴は、炭素数１～６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－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
Ｒ^f6は、炭素数１～２０のフッ素原子を有する飽和炭化水素基を表す。
ただし、Ｌ⁴⁴及びＲ^f6の合計炭素数の上限は２１である。］ Structural units represented by formula (a4-1) include structural units represented by formula (a4-2) and structural units represented by formula (a4-3).

[In formula (a4-2),
R ^f5 represents a hydrogen atom or a methyl group.
L ⁴⁴ represents an alkanediyl group having 1 to 6 carbon atoms, and --CH ₂ -- contained in the alkanediyl group may be replaced with --O-- or --CO--.
R ^f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and a fluorine atom.
However, the upper limit of the total carbon number of L ⁴⁴ and R ^f6 is 21. ]

Examples of the C 1-6 alkanediyl group for L ⁴⁴ include the same groups as those exemplified for A ^a41 .
Examples of the saturated hydrocarbon group for R ^f6 include the same groups as those exemplified for R ⁴² .
The alkanediyl group for L ⁴⁴ is preferably an alkanediyl group having 2 to 4 carbon atoms, more preferably an ethylene group.

Examples of structural units represented by formula (a4-2) include structural units represented by formulas (a4-1-1) to (a4-1-11). A structural unit in which the methyl group corresponding to R ^f5 in the structural unit (a4-2) is replaced with a hydrogen atom is also included as the structural unit represented by the formula (a4-2).

［式（ａ４－３）中、
Ｒ^f7は、水素原子又はメチル基を表す。
Ｌ⁵は、炭素数１～６のアルカンジイル基を表す。
Ａ^f13は、フッ素原子を有していてもよい炭素数１～１８の２価の飽和炭化水素基を表す。
Ｘ^f12は、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＡ^f13との結合部位を表す。）。
Ａ^f14は、フッ素原子を有していてもよい炭素数１～１７の飽和炭化水素基を表す。
但し、Ａ^f13及びＡ^f14の少なくとも１つは、フッ素原子を有し、Ｌ⁵、Ａ^f13及びＡ^f14の合計炭素数の上限は２０である。］

[In formula (a4-3),
R ^f7 represents a hydrogen atom or a methyl group.
L ⁵ represents an alkanediyl group having 1 to 6 carbon atoms.
A ^f13 represents a C 1-18 divalent saturated hydrocarbon group which may have a fluorine atom.
X ^f12 represents *--O--CO-- or *--CO--O-- (* represents a binding site with A ^f13 ).
A ^f14 represents a C 1-17 saturated hydrocarbon group which may have a fluorine atom.
However, at least one of A ^f13 and A ^f14 has a fluorine atom, and the upper limit of the total carbon number of L ⁵ , A ^f13 and A ^f14 is 20. ]

Examples of the alkanediyl group for L ⁵ include the same groups as those exemplified for the alkanediyl group for A ^a41 .

The divalent saturated hydrocarbon group optionally having a fluorine atom in A ^f13 preferably has a divalent chain saturated hydrocarbon group optionally having a fluorine atom and a fluorine atom is a divalent saturated alicyclic hydrocarbon group, more preferably a perfluoroalkanediyl group.
Examples of the divalent chain saturated hydrocarbon group which may have a fluorine atom include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group and a pentanediyl group; a difluoromethylene group, a perfluoroethylene group, perfluoroalkanediyl groups such as perfluoropropanediyl group, perfluorobutanediyl group and perfluoropentanediyl group;
The divalent saturated alicyclic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Monocyclic groups include a cyclohexanediyl group, a perfluorocyclohexanediyl group, and the like. Examples of polycyclic groups include an adamantanediyl group, a norbornanediyl group, a perfluoroadamantanediyl group, and the like.

Examples of saturated hydrocarbon groups and optionally fluorine-containing saturated hydrocarbon groups for A ^f14 include the same groups as those exemplified for R ^a42 . Among them, trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, Fluorination such as 2,2,3,3,4,4,5,5,5-nonafluoropentyl, pentyl, hexyl, perfluorohexyl, heptyl, perfluoroheptyl, octyl and perfluorooctyl groups Alkyl group, cyclopropylmethyl group, cyclopropyl group, cyclobutylmethyl group, cyclopentyl group, cyclohexyl group, perfluorocyclohexyl group, adamantyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl group, norbornylmethyl group, perfluoroadamantyl group , a perfluoroadamantylmethyl group, and the like.

In formula (a4-3), L ⁵ is preferably an ethylene group.
The divalent saturated hydrocarbon group of A ^f13 is preferably a group containing a divalent chain saturated hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, A divalent chain saturated hydrocarbon group having 2 to 3 carbon atoms is more preferred.
The saturated hydrocarbon group of A ^f14 is preferably a group containing a chain saturated hydrocarbon group having 3 to 12 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and a saturated chain hydrocarbon group having 3 to 10 carbon atoms. Groups containing a hydrocarbon group and an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms are more preferred. Among them, A ^f14 is preferably a group containing an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group. .

Examples of structural units represented by formula (a4-3) include structural units represented by formulas (a4-1′-1) to (a4-1′-11). A structural unit in which the methyl group corresponding to R ^f7 in the structural unit (a4-3) is replaced with a hydrogen atom is also included as the structural unit represented by the formula (a4-3).

［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の飽和炭化水素基を表す。］ Structural units (a4) also include structural units represented by formula (a4-4).

[In 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 C 1-10 saturated hydrocarbon group having a fluorine atom. ]

Examples of the saturated hydrocarbon group for R ^{f22 include those similar to the saturated hydrocarbon group for R a42 .} R ^f22 is preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom or an alicyclic saturated hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, and an alkyl group having 1 to 10 carbon atoms having a fluorine atom is preferably More preferred is an alkyl group having 1 to 6 carbon atoms and having a fluorine atom.

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.

As the structural unit represented by formula (a4-4), for example, in structural units represented by the following structural units and structural units represented by the following formulas, the methyl group corresponding to R ^f21 in structural unit (a4-4) is hydrogen Structural units replaced with atoms are included.

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。
Ｌ⁵⁵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－ＣＨ_２－は、－Ｏ－又は－ＣＯ－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) is preferably a group having an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include structural units represented by formula (a5-1).

[In the 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. .
L ⁵⁵ represents a single bond or 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— or —CO— . ]

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.
Aliphatic hydrocarbon groups having 1 to 8 carbon atoms are, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2 - alkyl groups such as ethylhexyl groups.
A 3-methyladamantyl group etc. are mentioned as an alicyclic hydrocarbon group which has a substituent.
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 divalent saturated hydrocarbon group for L ⁵⁵ includes a divalent saturated chain hydrocarbon group and a saturated divalent alicyclic hydrocarbon group, preferably a saturated chain divalent hydrocarbon group. .
Examples of divalent chain 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、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＬ^x1との結合部位を表す。）。
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。 Groups in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ⁵⁵ is replaced with —O— or —CO— include, for example, formulas (L1-1) to (L1-4) and the group represented by In the following formulas, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom.

In formula (L1-1),
X ^x1 represents *-O-CO- or *-CO-O- (* represents a binding site with L ^x1 ).
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 saturated aliphatic 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 the following structural units and structural units in which the methyl group corresponding to R ⁵¹ in the structural unit (a5-1) 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 unit (a6) is a structural unit having a —SO ₂ — group, and preferably has a —SO ₂ — group in its side chain.
A structural unit having a —SO ₂ — group may have a linear structure having a —SO ₂ — group, or may have a branched structure having a —SO ₂ — group, It may have a cyclic structure (monocyclic and polycyclic structures) having a —SO ₂ — group. Structural units having a cyclic structure containing —SO ₂ — groups are preferred, and structural units having a cyclic structure (sultone ring) containing —SO ₂ —O— are more preferred.

The sultone ring includes rings represented by the following formulas (T ¹ -1), (T ¹ -2), (T ¹ -3) and (T ¹ -4). The binding site can be at any position. The sultone ring may be monocyclic, but preferably polycyclic. A polycyclic sultone ring means a bridged ring containing —SO ₂ —O— as an atomic group constituting the ring, and is represented by formulas (T ¹ -1) and (T ¹ -2). ring. The sultone ring may further contain a heteroatom in addition to —SO ₂ —O— as an atomic group constituting the ring, like the ring represented by formula (T ¹ -2). A heteroatom includes an oxygen atom, a sulfur atom or a nitrogen atom, preferably an oxygen atom.

The sultone ring may have a substituent, and examples of the substituent include a halogen atom, an alkyl group having 1 to 12 carbon atoms optionally having a hydroxy group, a halogen atom, a hydroxy group, a cyano group, and 1 carbon atom. alkoxy groups of up to 12 carbon atoms, aryl groups of 6 to 12 carbon atoms, aralkyl groups of 7 to 12 carbon atoms, glycidyloxy groups, alkoxycarbonyl groups of 2 to 12 carbon atoms and alkylcarbonyl groups of 2 to 4 carbon atoms, and the like. be done.

Halogen atoms include fluorine, chlorine, bromine and iodine atoms.
Alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl and decyl groups, preferably alkyl groups having 1 to 6 carbon atoms, more preferably methyl groups. is.
The alkyl group having a halogen atom 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, a perfluorohexyl group, trichloromethyl group, tribromomethyl group and triiodomethyl group, preferably trifluoromethyl group.
Alkyl groups having a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a 2-hydroxyethyl group.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy and dodecyloxy groups.
Aryl groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumyl, mesityl, biphenyl, and phenanthryl groups. groups, 2,6-diethylphenyl groups and 2-methyl-6-ethylphenyl groups.
Aralkyl groups include benzyl, phenethyl, phenylpropyl, naphthylmethyl and naphthylethyl groups.
The alkoxycarbonyl group includes groups in which an alkoxy group and a carbonyl group such as a methoxycarbonyl group and an ethoxycarbonyl group are bonded, preferably an alkoxycarbonyl group having 6 or less carbon atoms, more preferably a methoxycarbonyl group. mentioned.
Alkylcarbonyl groups include acetyl, propionyl and butyryl groups.

［式（Ｔ１’）中、
Ｘ^１１は、酸素原子、硫黄原子又はメチレン基を表す。
Ｒ^４１は、ハロゲン原子又はヒドロキシ基を有していてもよい炭素数１～１２のアルキル基、ハロゲン原子、ヒドロキシ基、シアノ基、炭素数１～１２のアルコキシ基、炭素数６～１２のアリール基、炭素数７～１２のアラルキル基、グリシジルオキシ基、炭素数２～１２のアルコキシカルボニル基又は炭素数２～４のアルキルカルボニル基を表す。
ｍａは、０～９のいずれかの整数を表す。ｍａが２以上のとき、複数のＲ^４１は同一であっても異なってもよい。
結合部位は任意の位置である。］
Ｘ^１１は、好ましくは酸素原子又はメチレン基であり、より好ましくはメチレン基である。
Ｒ^４１としては、スルトン環の置換基と同様のものが挙げられ、ハロゲン原子又はヒドロキシ基を有していてもよい炭素数１～１２のアルキル基が好ましい。 A sultone ring having no substituent is preferred from the viewpoint of facilitating the production of the monomer leading to the structural unit (a6).
As the sultone ring, a ring represented by the following formula (T1') is preferable.

[in the formula (T1′),
X ¹¹ represents an oxygen atom, a sulfur atom or a methylene group.
R ⁴¹ is an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. aralkyl group having 7 to 12 carbon atoms, glycidyloxy group, alkoxycarbonyl group having 2 to 12 carbon atoms or alkylcarbonyl group having 2 to 4 carbon atoms.
ma represents an integer from 0 to 9; When ma is 2 or more, multiple R ⁴¹ may be the same or different.
The binding site can be any position. ]
X ¹¹ is preferably an oxygen atom or a methylene group, more preferably a methylene group.
As R ⁴¹ , the same substituents as those for the sultone ring can be mentioned, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group is preferred.

［式（Ｔ１）中、
Ｒ^８は、ハロゲン原子又はヒドロキシ基を有していてもよい炭素数１～１２のアルキル基、ハロゲン原子、ヒドロキシ基、シアノ基、炭素数１～１２のアルコキシ基、炭素数６～１２のアリール基、炭素数７～１２のアラルキル基、グリシジルオキシ基、炭素数２～１２のアルコキシカルボニル基あるいは炭素数２～４のアルキルカルボニル基を表す。
ｍは、０～９のいずれかの整数を表す。ｍが２以上のとき、複数のＲ^８は同一であっても異なってもよい。
結合部位は任意の位置である。］ As the sultone ring, a ring represented by formula (T1) is more preferable.

[In formula (T1),
R ⁸ is an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms. aralkyl group having 7 to 12 carbon atoms, glycidyloxy group, alkoxycarbonyl group having 2 to 12 carbon atoms or alkylcarbonyl group having 2 to 4 carbon atoms.
m represents any integer from 0 to 9; When m is 2 or more, multiple R ^8s may be the same or different.
The binding site can be any position. ]

Examples of R ⁸ include those similar to those of R ⁴¹ .
ma in formula (T1′) and m in formula (T1) are preferably 0 or 1, more preferably 0.

The ring represented by formula (T1′) and the ring represented by formula (T1) include the following rings. The binding site can be any position.

A structural unit having a sultone ring preferably has the following groups. * in the following group represents a binding site.

A structural unit having a —SO ₂ — group preferably further has a group derived from a polymerizable group. Examples of the polymerizable group include vinyl group, acryloyl group, methacryloyl group, acryloyloxy group, methacryloyloxy group, acryloylamino group, methacryloylamino group, acryloylthio group and methacryloylthio group.
Among them, the monomer leading to the structural unit (a6) is preferably a monomer having an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer.

［式（Ｉｘ）中、Ｒ^ｘ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。
Ａ^ｘｘは、酸素原子、－Ｎ（Ｒ^ｃ）－又は硫黄原子を表す。
Ａ^ｘ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－、－ＣＯ－又は－Ｎ（Ｒ^ｄ）－に置き換わっていてもよい。
Ｘ^１１は、酸素原子、硫黄原子又はメチレン基を表す。
Ｒ^４１は、ハロゲン原子又はヒドロキシ基を有していてもよい炭素数１～１２のアルキル基、ハロゲン原子、ヒドロキシ基、シアノ基、炭素数１～１２のアルコキシ基、炭素数６～１２のアリール基、炭素数７～１２のアラルキル基、グリシジルオキシ基、炭素数２～１２のアルコキシカルボニル基又は炭素数２～４のアルキルカルボニル基を表す。
ｍａは、０～９のいずれかの整数を表す。ｍａが２以上のとき、複数のＲ^４１は同一であっても異なってもよい。
Ｒ^ｃ及びＲ^ｄは、互いに独立に、水素原子又は炭素数１～６のアルキル基を表す。］ Structural unit (a6) is preferably a structural unit represented by formula (Ix).

[In formula (Ix), R ^x represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ^xx represents an oxygen atom, -N(R ^c )- or a sulfur atom.
A ^x represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group is —O—, —CO— or —N(R ^d )— may be replaced.
X ¹¹ represents an oxygen atom, a sulfur atom or a methylene group.
R ⁴¹ is an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. aralkyl group having 7 to 12 carbon atoms, glycidyloxy group, alkoxycarbonyl group having 2 to 12 carbon atoms or alkylcarbonyl group having 2 to 4 carbon atoms.
ma represents any integer from 0 to 9; When ma is 2 or more, multiple R ⁴¹ may be the same or different.
R ^c and R ^d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. ]

Halogen atoms for R ^x include fluorine, chlorine, bromine and iodine atoms.
The alkyl group for R ^x includes, for example, 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. and 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 ^x includes, for example, a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. , perfluorohexyl group, trichloromethyl group, tribromomethyl group and triiodomethyl group.
R ^x 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.

The divalent saturated hydrocarbon group for A ^x includes a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic bivalent alicyclic saturated hydrocarbon group. A combination of two or more of the groups may also be used.
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, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-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- a branched alkanediyl group such as a 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.

Examples of R ⁴¹ , X ¹¹ and ma are the same as those of formula (T1′).
Examples of the sultone ring include those described above, and among these, the above-described ones whose binding positions are specified are preferable.

Structural units (a6) include the following structural units.

Among them, structural units represented by formula (a6-1), formula (a6-2), formula (a6-6), formula (a6-7), formula (a6-8) and formula (a6-12) are preferred, and structural units represented by formulas (a6-1), (a6-2), (a6-7) and (a6-8) are more preferred.
When the resin (A) has the structural unit (a6), the content thereof is preferably 1 to 50 mol%, more preferably 2 to 40 mol%, based on the total structural units of the resin (A), and 3 ~30 mol% is more preferred.

<Structural unit (II)>
The resin (A) may further contain a structural unit that is decomposed by exposure to generate an acid (hereinafter sometimes referred to as "structural unit (II)"). Specific examples of the structural unit (II) include structural units described in JP-A-2016-79235. A structural unit having a group and an organic anion is preferred.

［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。
ＺＡ^＋は、有機カチオンを表す。］ A structural unit having a sulfonate group or carboxylate group and an organic cation 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.
ZA ⁺ 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.
The perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted in A ^x1 includes a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, and a perfluorotert -butyl group, perfluoropentyl group, perfluorohexyl group and the like.

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, bivalent monocyclic alicyclic saturated hydrocarbon group such as cycloalkanediyl group such as cyclooctane-1,5-diyl group; norbornane-1,4-diyl group, norbornane-2, Bivalent polycyclic alicyclic saturated hydrocarbon groups such as 5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group are included.

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 formula below, * and ** represent binding sites, and * represents a binding site with ^Ax1 .

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 a divalent saturated hydrocarbon 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.

Organic cations represented by ZA ⁺ include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, a cation represented by any one of formulas (b2-1) to (b2-4) described below (hereinafter, may be referred to as "cation (b2-1)" or the like depending on the formula number. ).

［式（ＩＩ－２－Ａ）中、
Ｒ^ＩＩＩ３、Ｘ^ＩＩＩ３及びＺＡ^＋は、上記と同じ意味を表す。
ｚは、０～６のいずれかの整数を表す。
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は互いに同一でも、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 the formula (II-2-A),
R ^III3 , X ^III3 and ZA ⁺ have the same meanings as above.
z represents any integer from 0 to 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 may be the same or different may be
Q ^a and Q ^b each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group. ]

Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by R ^III2 , R ^III4 , Q ^a and Q ^b include the same perfluoroalkyl groups having 1 to 6 carbon atoms represented by Q ^b1 described later. .

［式（ＩＩ－２－Ａ－１）中、
Ｒ^ＩＩＩ２、Ｒ^ＩＩＩ３、Ｒ^ＩＩＩ４、Ｑ^a、Ｑ^b、ｚ及びＺＡ^＋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。
Ｘ^Ｉ2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 the formula (II-2-A-1),
R ^III2 , R ^III3 , R ^III4 , Q ^a , Q ^b , z and ZA ⁺ have the same meanings as above.
R ^III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
X ^I2 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 represented by X ^I2 includes the same divalent saturated hydrocarbon groups as those represented by X ^III3 .

［式（ＩＩ－２－Ａ－２）中、
Ｒ^ＩＩＩ３、Ｒ^ＩＩＩ５及びＺＡ^＋は、上記と同じ意味を表す。
ｍ及びｎＡは、それぞれ独立に、１又は２を表す。］ As the structural unit represented by formula (II-2-A-1), a structural unit represented by formula (II-2-A-2) is preferable.

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

Structural units represented by formula (II-2-A′) include, for example, the following structural units, a group corresponding to a methyl group in R ^III3 is a hydrogen atom, a halogen atom (e.g., a fluorine atom) or a halogen atom Structural units and structural units described in International Publication No. 2012/050015 substituted with an alkyl group having 1 to 6 carbon atoms (eg, trifluoromethyl group, etc.) which may have ZA ⁺ 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いてもよい炭素数１～６のアルキル基を表す。
Ａ^－は、有機アニオンを表す。］
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で表される炭化水素基としては、アルキル基、脂環式炭化水素基、芳香族炭化水素基及びこれらを組み合わせることにより形成される基等が挙げられる。
アルキル基及び脂環式炭化水素基は、上記と同様のものが挙げられる。
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、ビフェニル基、フェナントリル基等のアリール基が挙げられる。
組み合わせた基としては、上述したアルキル基と脂環式炭化水素基とを組み合わせた基、ベンジル基等のアラルキル基、アルキル基を有する芳香族炭化水素基（ｐ－メチルフェニル基、ｐ－ｔｅｒｔ－ブチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、２，６－ジエチルフェニル基、２－メチル－６－エチルフェニル基等）、脂環式炭化水素基を有する芳香族炭化水素基（ｐ－シクロヘキシルフェニル基、ｐ－アダマンチルフェニル基等）、フェニルシクロヘキシル基等のアリール－シクロアルキル基等が挙げられる。
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^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。 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. ]
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 groups represented by R ^II2 and R ^II3 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 aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl groups.
Examples of the combined group include a group obtained by combining an alkyl group and an alicyclic hydrocarbon group described above, an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert- butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having alicyclic hydrocarbon groups ( p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like.
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.
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 .

As the structural unit containing a cation in formula (II-1-1), the structural unit represented below, a group corresponding to a methyl group in R ^II4 is a hydrogen atom, a halogen atom (e.g., a fluorine atom) or a halogen Structural units substituted with alkyl groups having 1 to 6 carbon atoms which may have atoms (eg, trifluoromethyl group, etc.) and the like can be mentioned.

Organic anions represented by A ⁻ include sulfonate anions, sulfonylimide anions, sulfonylmethide anions and carboxylate anions. The organic anion represented by A ⁻ is preferably a sulfonate anion, and examples of the sulfonate anion include the same anions as those represented by formula (B1) described below.

Sulfonylimide anions represented by A ⁻ include the following.

Sulfonylmethide anions include the following.

Carboxylate anions include the following.

Examples of structural units represented by formula (II-1-1) 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) may have structural units other than the structural units described above, and examples of such structural units include structural units well known in the art.

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 the group consisting of structural unit (a1-0), structural unit (a1-1) and structural unit (a1-2), more preferably structural unit (a1-1) and structural unit (a1-2), more preferably at least one selected from the group consisting of structural unit (a1-1) and structural unit (a1-2) There are two types.
Structural unit (s) is preferably at least one selected from the group consisting of structural unit (a2) and structural unit (a3). Structural unit (a2) is preferably a structural unit represented by formula (a2-1) or a structural unit represented by formula (a2-A). Structural unit (a3) is preferably a group consisting of a structural unit represented by formula (a3-1), a structural unit represented by formula (a3-2) and a structural unit represented by formula (a3-4) is at least one selected from

Each structural unit that constitutes the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (e.g., radical polymerization method) using a monomer that leads to these structural units. be able to. 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.

<Resins other than resin (A)>
The resist composition of the present invention may contain a resin other than resin (A).
Examples of the resin other than the resin (A) include a resin containing the structural unit (a4) or the structural unit (a5) (hereinafter sometimes referred to as resin (X)).

As the resin (X), among others, a resin containing the structural unit (a4) is preferable.
In the resin (X), the content of the structural unit (a4) is preferably 30 mol% or more, more preferably 40 mol% or more, relative to the total of all structural units of the resin (X). , more preferably 45 mol % or more.
Structural units that the resin (X) may further include structural units (a2), structural units (a3), and structural units derived from other known monomers. Among them, the resin (X) is preferably a resin consisting only of the structural unit (a4) and/or the structural unit (a5), more preferably a resin consisting only of the structural unit (a4).
Each structural unit constituting the resin (X) may be used alone or in combination of two or more. Using a monomer that induces these structural units, the polymer 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, more preferably 1 to 30 parts by mass, and even more preferably 1 to 8 parts by mass.

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

<Acid Generator (B)>
The acid generator (B) may be either nonionic or ionic. Nonionic acid generators include sulfonate esters (eg 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (eg disulfone, ketosulfone, sulfonyldiazomethane) and the like. Typical ionic acid generators are onium salts containing onium cations (eg, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). The anions of the onium salts include sulfonate anions, sulfonylimide anions, sulfonylmethide anions, and the like.

Examples of the acid generator (B) include JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, US Pat. No. 3,779,778, US Pat. A compound that generates an acid upon exposure to radiation as described in 1. above can be used. Moreover, you may use the compound manufactured by the well-known method. The acid generator (B) may be used in combination of two or more.

［式（Ｂ１）中、
Ｑ^b1及びＱ^b2は、それぞれ独立に、水素原子、フッ素原子、炭素数１～６のアルキル基又は炭素数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２価の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３～２４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－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ｚ１^＋は、有機カチオンを表す。］ The acid generator (B) is more preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)").

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO— , a hydrogen atom contained in the divalent saturated hydrocarbon 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 24 carbon atoms, included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -S-, -SO ₂ - or -CO-.
Z1 ⁺ represents an organic cation. ]

The perfluoroalkyl groups of Q ^b1 and Q ^b2 include 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 and the like can be mentioned.
Examples of alkyl groups for Q ^b1 and Q ^b2 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl and hexyl groups.
The acid generator (B) is preferably a fluorine-containing acid generator, at least one of Q ^b1 and Q ^b2 preferably contains a fluorine atom or a perfluoroalkyl group, and at least one of them is a fluorine atom or a perfluoroalkyl group. It is more preferably an alkyl group, more preferably a fluorine atom or a trifluoromethyl group, and even more preferably both a fluorine atom.

The divalent saturated hydrocarbon group for L ^b1 includes a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic bivalent alicyclic saturated hydrocarbon group. A group formed by combining two or more of the groups 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 bivalent 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.

Groups in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced with —O— or —CO— include, for example, formulas (b1-1) to (b1-3) A group represented by any one of is mentioned. In addition, in the groups represented by formulas (b1-1) to (b1-3) and the groups represented by formulas (b1-4) to (b1-11) which are specific examples thereof, * and * * represents the binding site, * represents the binding site with -Y.

［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との炭素数合計は、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との炭素数合計は、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との炭素数合計は、２３以下である。］

[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 number of carbon atoms 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 number of carbon atoms 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 number of carbon atoms of L ^b6 and L ^b7 is 23 or less. ]

In the groups represented by formulas (b1-1) to (b1-3), when —CH ₂ — contained in the saturated hydrocarbon group is replaced with —O— or —CO—, carbon before replacement Let the number be the number of carbon atoms of the saturated hydrocarbon group.
As the divalent saturated hydrocarbon group, the same divalent saturated hydrocarbon group as L ^b1 can be mentioned.
L ^b2 is preferably a single bond, a methylene group, —CH(CF ₃ )—, —C(CF ₃ ) ₂ —.
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, hydrogen atoms contained in the divalent saturated hydrocarbon group may be substituted with fluorine atoms, methylene group, - CH(CF ₃ )—, —C(CF ₃ ) ₂ — are preferred.
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—.

［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し、該２価の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。
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し、該２価の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。
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し、該２価の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。
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。］
Ｌ^b8は、好ましくは炭素数１～４の２価の飽和炭化水素基である。
Ｌ^b9は、好ましくは炭素数１～８の２価の飽和炭化水素基である。
Ｌ^b10は、好ましくは単結合又は炭素数１～１９の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１～８の２価の飽和炭化水素基である。
Ｌ^b11は、好ましくは炭素数１～８の２価の飽和炭化水素基である。
Ｌ^b12は、好ましくは単結合又は炭素数１～８の２価の飽和炭化水素基である。
Ｌ^b13は、好ましくは炭素数１～１２の２価の飽和炭化水素基である。
Ｌ^b14は、好ましくは単結合又は炭素数１～６の２価の飽和炭化水素基である。
Ｌ^b15は、好ましくは単結合又は炭素数１～１８の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１～８の２価の飽和炭化水素基である。
Ｌ^b16は、好ましくは炭素数１～１２の２価の飽和炭化水素基である。
Ｌ^b17は、好ましくは炭素数１～６の２価の飽和炭化水素基である。
Ｌ^b18は、好ましくは単結合又は炭素数１～１７の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１～４の２価の飽和炭化水素基である。 The group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced with —O— or —CO— is represented by formula (b1-1) or formula (b1-3). are preferred.
Examples of the group represented by formula (b1-1) include groups represented by 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, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—.
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, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced with —O— or —CO— good too.
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, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—.
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 C 1-6 divalent saturated hydrocarbon group.
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ルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アルキルカルボニ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す。
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ルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アルキルカルボニ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^b22及び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す。
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ルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アルキルカルボニ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^b25及びＬ^b26の合計炭素数は２１以下である。］ Examples of the group represented by formula (b1-3) include groups represented by 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 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 saturated hydrocarbon group being substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group; good too. --CH ₂ -- contained in the alkylcarbonyloxy group may be replaced with --O-- or --CO--, and a hydrogen atom contained in the alkylcarbonyloxy 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 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.
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 saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group; good too. --CH ₂ -- contained in the alkylcarbonyloxy group may be replaced with --O-- or --CO--, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b21 , L ^b22 and 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 saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
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 saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group; good too. --CH ₂ -- contained in the alkylcarbonyloxy group may be replaced with --O-- or --CO--, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b24 , L ^b25 and L ^b26 is 21 or less. ]

In addition, in the group represented by formula (b1-9) to the group represented by formula (b1-11), when the hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, it is replaced Let the previous carbon number be the carbon number of this saturated hydrocarbon group.
The alkylcarbonyloxy group includes an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, an adamantylcarbonyloxy group and the like.

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.

Ｙで表される脂環式炭化水素基としては、好ましくは式（Ｙ１）～式（Ｙ２０）、式（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）～式（Ｙ４３）のいずれかで表される基であり、より好ましくは式（Ｙ１１）、式（Ｙ１５）、式（Ｙ１６）、式（Ｙ２０）、式（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）、式（Ｙ４０）、式（Ｙ４２）又は式（Ｙ４３）で表される基であり、さらに好ましくは式（Ｙ１１）、式（Ｙ１５）、式（Ｙ２０）、式（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）、式（Ｙ４０）、式（Ｙ４２）又は式（Ｙ４３）で表される基である。
Ｙで表される脂環式炭化水素基が式（Ｙ２８）～式（Ｙ３５）、式（Ｙ３９）、式（Ｙ４０）、式（Ｙ４２）又は式（Ｙ４３）等の酸素原子を含むスピロ環である場合には、２つの酸素原子間のアルカンジイル基は、１以上のフッ素原子を有することが好ましい。また、ケタール構造に含まれるアルカンジイル基のうち、酸素原子に隣接するメチレン基には、フッ素原子が置換されていないのが好ましい。 The alicyclic hydrocarbon group in which —CH ₂ — contained in the alicyclic hydrocarbon group represented by Y is not replaced with —O—, —S—, —SO ₂ —, or —CO— includes, for example, Examples include groups represented by formulas (Y1) to (Y11) and formulas (Y36) to (Y38).
When —CH ₂ — contained in the alicyclic hydrocarbon group represented by Y is replaced with —O—, —S—, —SO ₂ — or —CO—, the number may be 1, or 2 or more. It's okay. Such groups include groups represented by formulas (Y12) to (Y35) and formulas (Y39) to (Y43). —O— or —CO— in groups represented by formulas (Y12) to (Y35) and formulas (Y39) to (Y43) may be replaced with —S— or —SO ₂ —. * represents the binding site with L ^b1 .

The alicyclic hydrocarbon group represented by Y is preferably represented by formulas (Y1) to (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), and formula (Y39). to a group represented by any one of formula (Y43), more preferably formula (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y26), formula (Y27), formula (Y30), a group represented by formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43), more preferably formula (Y11), formula (Y15) or formula (Y20), a group represented by formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43) .
The alicyclic hydrocarbon group represented by Y is a spiro ring containing an oxygen atom such as formulas (Y28) to (Y35), formula (Y39), formula (Y40), formula (Y42) or formula (Y43) In some cases it is preferred that the alkanediyl group between the two oxygen atoms has one or more fluorine atoms. Further, among the alkanediyl groups contained in the ketal structure, the methylene group adjacent to the oxygen atom is preferably not substituted with a fluorine atom.

Examples of substituents of the methyl group represented by Y include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, -( CH ₂ ) _ja —CO—O—R ^b1 group or —(CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is a C 1-16 alkyl group, a C 3-16 represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, and —CH ₂ — contained in the alkyl group and the alicyclic hydrocarbon group is —O— , —SO ₂ — or —CO—, and the hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group is replaced with a hydroxy group or a fluorine atom ja represents any integer from 0 to 4.) and the like.
Substituents for the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, and an alkyl group having 1 to 16 carbon atoms optionally substituted by a hydroxy group (-CH ₂ - may be replaced with -O- or -CO-.), an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aromatic hydrocarbon group having 7 to 21 carbon atoms, aralkyl group, glycidyloxy group, —(CH ₂ ) _ja —CO—O—R ^b1 group or —(CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is C 1-16 represents an alkyl group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, and is included in the alkyl group and the alicyclic hydrocarbon group —CH ₂ — may be replaced with —O—, —SO ₂ — or —CO—, and hydrogen atoms contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group are may be substituted with a hydroxy group or a fluorine atom, and ja represents an integer of 0 to 4).

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. The alicyclic hydrocarbon group may have a chain hydrocarbon group, such as a methylcyclohexyl group and a dimethylcyclohexyl group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3-12, more preferably 3-10.
Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl groups. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group having a chain hydrocarbon group having 1 to 18 carbon atoms (tolyl group, xylyl group, cumenyl group, mesityl group, p-methylphenyl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), and carbon Examples thereof include aromatic hydrocarbon groups having alicyclic hydrocarbon groups of numbers 3 to 18 (p-adamantylphenyl group, p-cyclohexylphenyl group, etc.). The number of carbon atoms in the aromatic hydrocarbon group is preferably 6-14, more preferably 6-10.
Examples of alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group and nonyl. group, decyl group, undecyl group, dodecyl group and the like. The number of carbon atoms in the alkyl group is preferably 1-12, more preferably 1-6, still more preferably 1-4.
Alkyl groups substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group.
Aralkyl groups include benzyl, phenethyl, phenylpropyl, naphthylmethyl and naphthylethyl groups.
The groups in which —CH ₂ — contained in the alkyl group is replaced with —O—, —SO ₂ —, —CO—, etc. include an alkoxy group, an alkylsulfonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, or Groups in which these are combined, and the like are included.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy and dodecyloxy groups. The alkoxy group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and still more preferably 1 to 4 carbon atoms.
The alkylsulfonyl group includes a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group and the like. The number of carbon atoms in the alkylsulfonyl group is preferably 1-12, more preferably 1-6, still more preferably 1-4.
Examples of alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl and butoxycarbonyl groups. The alkoxycarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and still more preferably 2 to 4 carbon atoms.
Alkylcarbonyl groups include, for example, acetyl, propionyl and butyryl groups. The number of carbon atoms in the alkylcarbonyl group is preferably 2-12, more preferably 2-6, still more preferably 2-4.
The alkylcarbonyloxy group includes, for example, an acetyloxy group, a propionyloxy group, a butyryloxy group and the like. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2-12, more preferably 2-6, still more preferably 2-4.
Examples of the combined group include, for example, a group in which an alkoxy group and an alkyl group are combined, a group in which an alkoxy group and an alkoxy group are combined, a group in which an alkoxy group and an alkylcarbonyl group are combined, an alkoxy group and an alkylcarbonyloxy group, and and the like.
Examples of groups in which an alkoxy group and an alkyl group are combined include alkoxyalkyl groups such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group and an ethoxymethyl group. The alkoxyalkyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and still more preferably 2 to 4 carbon atoms.
Groups in which an alkoxy group and an alkoxy group are combined include alkoxyalkoxy groups such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, and an ethoxyethoxy group. The alkoxyalkoxy group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and still more preferably 2 to 4 carbon atoms.
Groups in which an alkoxy group and an alkylcarbonyl group are combined include alkoxyalkylcarbonyl groups such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group and an ethoxypropionyl group. The alkoxyalkylcarbonyl group preferably has 3 to 13 carbon atoms, more preferably 3 to 7 carbon atoms, and still more preferably 3 to 5 carbon atoms.
Groups in which an alkoxy group and an alkylcarbonyloxy group are combined include alkoxyalkylcarbonyloxy groups such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group and an ethoxypropionyloxy group. The alkoxyalkylcarbonyloxy group preferably has 3 to 13 carbon atoms, more preferably 3 to 7 carbon atoms, and still more preferably 3 to 5 carbon atoms.
Groups in which —CH ₂ — contained in the alicyclic hydrocarbon group is replaced with —O—, —SO ₂ —, or —CO— include formulas (Y12) to (Y35), formulas (Y39) to A group represented by (Y43) and the like can be mentioned.

Examples of Y include the following.

Y is preferably an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, more preferably an optionally substituted alicyclic hydrocarbon group having 3 to 20 carbon atoms A hydrocarbon group, more preferably an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, still more preferably an optionally substituted adamantyl group or a substituted a norbornyl group optionally having a group, wherein —CH ₂ — constituting the alicyclic hydrocarbon group, adamantyl group or norbornyl group is replaced with —O—, —SO ₂ — or —CO— good too. Y is specifically preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, a norbornanelactone group, or represented by formula (Y42), formula (Y100) to formula (Y114), formula (Y134) to formula (Y139). is a group.

Examples of the anion in the salt represented by formula (B1) include anions represented by formulas (B1-A-1) to (B1-A-62) [hereinafter referred to as "anion (B1-A -1)”, etc. ] is preferable, formula (B1-A-1) ~ formula (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula (B1-A-24) ~ formula (B1-A-33), Formula (B1-A-36) ~ Formula (B1-A-40), Formula (B1-A-47) ~ Formula (B1-A-62) Anions are more preferred.

Here, R ⁱ² to R ⁱ⁷ are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R ⁱ⁸ is, for example, a chain 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. group, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L ^A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q ^b1 and Q ^b2 have the same meanings as above.
Specific examples of the anion in the salt represented by formula (B1) include the anions described in JP-A-2010-204646.

Anions in the salt represented by Formula (B1) are preferably anions represented by Formulas (B1a-1) to (B1a-40).

Among them, formula (B1a-1) ~ formula (B1a-3), formula (B1a-7) ~ formula (B1a-16), formula (B1a-18), formula (B1a-19), formula (B1a-22 ) to formula (B1a-40) are preferred.

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の鎖式炭化水素基、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、該鎖式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、炭素数１～１８の脂肪族炭化水素基、炭素数１～１２のフッ化アルキル基又は炭素数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、互いに結合してそれらが結合する硫黄原子と一緒になって環を形成してもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－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、ハロゲン原子、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基、炭素数１～１２のフッ化アルキル基又は炭素数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の鎖式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、互いに結合してそれらが結合する硫黄原子と一緒になって環を形成してもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－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の鎖式炭化水素基、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の鎖式炭化水素基、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、該鎖式炭化水素基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、互いに結合してそれらが結合する－ＣＨ－ＣＯ－を含めて環を形成していてもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－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、ハロゲン原子、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基、炭素数１～１２のフッ化アルキル基又は炭素数１～１２のアルコキシ基を表す。
Ｒ^b13とＲ^b14とは、互いに結合してそれらが結合するベンゼン環と一緒になって硫黄原子を含む環を形成してもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｌ^b31は、硫黄原子又は酸素原子を表す。
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は同一又は相異なり、ｐ２が２以上のとき、複数のＲ^b14は同一又は相異なり、ｑ２が２以上のとき、複数のＲ^b15は同一又は相異なり、ｒ２が２以上のとき、複数のＲ^b16は同一又は相異なり、ｓ２が２以上のとき、複数のＲ^b17は同一又は相異なり、ｔ２が２以上のとき、複数のＲ^b18は同一又は相異なる。
ｕ２が０のとき、ｏ２、ｐ２、ｑ２及びｒ２のうちいずれか１つは１以上であり、Ｒ^b13～Ｒ^b1６のうち少なくとも１つはハロゲン原子であることが好ましく、ｕ２が１のとき、ｏ２、ｐ２、ｓ２、ｔ２、ｑ２及びｒ２のうちいずれか１つは１以上であり、Ｒ^b13～Ｒ^b18のうち少なくとも１つはハロゲン原子であることが好ましい。
さらに、ｕ２が０のとき、ｒ２は１以上であることが好ましく、１であることがさらに好ましい。また、ｕ２が０、かつ、ｒ２が１以上のとき、Ｒ^ｂ１６がハロゲン原子であることが好ましい。 Organic cations of Z1 ⁺ include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, a cation represented by any one of formulas (b2-1) to (b2-4) (hereinafter sometimes referred to as "cation (b2-1)" etc. depending on the formula number) is mentioned.

In formulas (b2-1) to (b2-4),
R ^b4 to R ^b6 each independently represent a chain 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 chain 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 the hydrogen atom contained in the aromatic hydrocarbon group is a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or a carbon It may be substituted with 1 to 12 alkoxy groups.
R ^b4 and R ^b5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be —O—, —S— or -CO- may be substituted.
R ^b7 and R ^b8 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl 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, multiple R ^b7 may be the same or different, and when n2 is 2 or more, multiple R ^b8 may be the same or different.
R ^b9 and R ^b10 each independently represent a chain 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 be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be —O—, —S— or -CO- may be substituted.
R ^b11 represents a hydrogen atom, a chain 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 a chain 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 the chain hydrocarbon group The hydrogen atoms contained may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atoms contained in the aromatic hydrocarbon groups are alkoxy groups having 1 to 12 carbon atoms or 1 carbon atoms. It may be optionally substituted with ˜12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may be bonded to each other to form a ring including —CH—CO— to which they are bonded, and —CH ₂ — contained in the ring may be —O—, —S - or -CO- may be substituted.
R ^b13 to R ^b18 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. .
R ^b13 and R ^b14 may combine with each other to form a sulfur atom-containing ring together with the benzene ring to which they are bonded, and —CH ₂ — contained in the ring may be —O—, -S- or -CO- may be substituted.
L ^b31 represents a sulfur atom or an oxygen atom.
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, multiple R ^b13 are the same or different, when p2 is 2 or more, multiple R ^b14 are the same or different, and when q2 is 2 or more, multiple R ^b15 are the same or different. , when r2 is 2 or more, the plurality of R ^b16 are the same or different; when s2 is 2 or more, the plurality of R ^b17 are the same or different; when t2 is 2 or more, the plurality of R ^b18 are the same or different; different.
When u2 is 0, any one of o2, p2, q2 and r2 is 1 or more, and at least one of R ^b13 to R ^b16 is preferably a halogen atom; Any one of o2, p2, s2, t2, q2 and r2 is 1 or more, and at least one of R ^b13 to R ^b18 is preferably a halogen atom.
Furthermore, when u2 is 0, r2 is preferably 1 or more, more preferably 1. Further, when u2 is 0 and r2 is 1 or more, ^Rb16 is preferably a halogen atom.

特に、Ｒ^b9～Ｒ^b12の脂環式炭化水素基は、好ましくは炭素数３～１８、より好ましくは炭素数４～１２である。 An aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group.
Chain hydrocarbon groups include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. mentioned.
In particular, chain hydrocarbon groups of R ^b9 to R ^b12 preferably have 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclo Cycloalkyl groups such as a heptyl group, a cyclooctyl group, and a cyclodecyl group can be mentioned. The polycyclic alicyclic hydrocarbon group includes decahydronaphthyl group, adamantyl group, norbornyl group and the following groups.

In particular, the alicyclic hydrocarbon groups of R ^b9 to R ^b12 preferably have 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.

Alicyclic hydrocarbon groups in which hydrogen atoms are substituted with aliphatic hydrocarbon groups include methylcyclohexyl group, dimethylcyclohexyl group, 2-methyladamantan-2-yl group, and 2-ethyladamantan-2-yl group. , 2-isopropyladamantan-2-yl group, methylnorbornyl group, isobornyl group and the like. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total carbon number of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.
A fluorinated alkyl group represents an alkyl group having 1 to 12 carbon atoms and having a fluorine atom, and includes a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group, and the like. The number of carbon atoms in the fluorinated alkyl group is preferably 1-9, more preferably 1-6, still more preferably 1-4.

The aromatic hydrocarbon group includes aryl groups such as phenyl group, biphenyl group, naphthyl group and phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and aromatic hydrocarbon groups having chain hydrocarbon groups (tolyl, xylyl, cumenyl, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and an aromatic hydrocarbon group having an alicyclic hydrocarbon group ( p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) and the like.
In addition, when the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms is preferred.
Aromatic hydrocarbon groups in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group and the like.
Chain hydrocarbon groups in which hydrogen atoms are substituted with aromatic hydrocarbon groups include aralkyl groups such as benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl and naphthylethyl groups.

Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy and dodecyloxy groups.
An acetyl group, a propionyl group, a butyryl group, etc. are mentioned as an alkylcarbonyl group.
Halogen atoms include fluorine, chlorine, bromine and iodine atoms.
The alkylcarbonyloxy group includes a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group and a pentylcarbonyloxy group. , hexylcarbonyloxy group, octylcarbonyloxy group and 2-ethylhexylcarbonyloxy group.

The ring formed by R ^b4 and R ^b5 bonded together with the sulfur atom to which they are bonded may be monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. may be a ring of This ring includes a ring having 3 to 18 carbon atoms, preferably a ring having 4 to 18 carbon atoms. Further, the ring containing a sulfur atom includes a 3- to 12-membered ring, preferably a 3- to 7-membered ring, and examples thereof include the following rings. * represents a binding site.

The ring formed by R ^b9 and R ^b10 together may be a monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated ring. This ring includes a 3- to 12-membered ring, preferably a 3- to 7-membered ring. Examples include thiolan-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring, 1,4-oxathian-4-ium ring and the like.
The ring formed by R ^b11 and R ^b12 together may be a monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated ring. This ring includes a 3- to 12-membered ring, preferably a 3- to 7-membered ring. oxocycloheptane ring, oxocyclohexane ring, oxonorbornane ring, oxoadamantane ring and the like.

Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferred.
Examples of the cation (b2-1) include the following cations.

Examples of the cation (b2-2) include the following cations.

Examples of the cation (b2-3) include the following cations.

Examples of the cation (b2-4) include the following cations.

The acid generator (B) is a combination of the aforementioned anions and the aforementioned organic cations, and these can be combined arbitrarily. As the acid generator (B), preferably formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-16), formula (B1a-18), formula (B1a- 19), an anion represented by any one of formulas (B1a-22) to (B1a-38) and cation (b2-1), cation (b2-2), cation (b2-3) or cation (b2 -4).

As the acid generator (B), those represented by formulas (B1-1) to (B1-60) are preferred. Among them, those containing an arylsulfonium cation are preferable, and formulas (B1-1) to (B1-3), formulas (B1-5) to (B1-7), formulas (B1-11) to (B1-14) ), formulas (B1-20) to (B1-26), formulas (B1-29), and formulas (B1-31) to (B1-60) are particularly preferred.

In the resist composition of the present invention, the content of the acid generator is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 3 parts by mass or more and 40 parts by mass, relative to 100 parts by mass of the resin (A). parts or less, more preferably 10 parts by mass or more and 40 parts by mass or less.

<Solvent (E)>
The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, more preferably 94% by mass or more and 99% by mass. % or less. 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 kind of the solvent (E) may be used alone, or two or more kinds may be used.

<Quencher (C)>
The quencher (C) includes a basic nitrogen-containing organic compound and a salt that generates an acid weaker in acidity than the acid generated from the acid generator (B). When the resist composition contains the quencher (C), the content of the quencher (C) is preferably about 0.01 to 15% by mass, based on the solid content of the resist composition. It is more preferably about 01 to 10% by mass, even more preferably about 0.1 to 8% by mass, even more preferably about 0.1 to 7% by mass.
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.
Amines include 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, tri heptylamine, 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, tri isopropanolamine, 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-pyridyloxy ) ethane, di(2-pyridyl) ketone, 4,4′-dipyridyl sulfide, 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipicolylamine, bipyridine and the like, Diisopropylaniline is preferred, and 2,6-diisopropylaniline is more preferred.
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;

The acidity of a salt that generates an acid weaker than the acid generated from the acid generator (B) 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 (B) has an acid dissociation constant of -3<pKa, preferably -1<. Salts with pKa<7, more preferably salts with 0<pKa<5.
Examples of the salt that generates an acid weaker in acidity than the acid generated from the acid generator (B) include salts represented by the following formula, and salts represented by the formula (D) described in JP-A-2015-147926. (Hereinafter, it may be referred to as "weak acid inner salt (D)".), and JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502. and salts described in JP-A-2011-191745. Preferred is a salt (salt having a carboxylic acid anion) that generates a carboxylic acid having a weaker acidity than the acid generated from the acid generator (B), more preferably a weak acid inner salt (D), Of the weak acid inner salts (D), diphenyliodonium salts containing a phenyl group substituted with a carboxylate anion are more preferred.

As the weak acid inner salt (D), diphenyliodonium having an iodonium cation to which two phenyl groups are bonded and a carboxylate anion substituted by at least one of the two phenyl groups bonded to the iodonium cation. Salts are preferred, and specific examples include salts represented by the following formulas.

［式（Ｄ）中、
Ｒ^D1及びＲ^D2は、それぞれ独立に、炭素数１～１２の炭化水素基、炭素数１～６のアルコキシ基、炭素数２～７のアシル基、炭素数２～７のアシルオキシ基、炭素数２～７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ’及びｎ’は、それぞれ独立に、０～４のいずれかの整数を表し、ｍ’が２以上の場合、複数のＲ^D1は同一であっても異なってもよく、ｎ’が２以上の場合、複数のＲ^D2は同一であっても異なってもよい。］
Ｒ^D1及びＲ^D2の炭化水素基としては、鎖式炭化水素基、脂環式炭化水素基、芳香族炭化水素基及びこれらを組み合わせることにより形成される基等が挙げられる。
鎖式炭化水素基としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、ｔｅｒｔ－ブチル基、ペンチル基、ヘキシル基、ノニル基等のアルキル基が挙げられる。
脂環式炭化水素基としては、単環式及び多環式のいずれでもよく、飽和及び不飽和のいずれでもよい。シクロプロピル基、シクロブチル基、シクロペンチル基、シクロへキシル基、シクロノニル基、シクロドデシル基等のシクロアルキル基、ノルボニル基、アダマンチル基等が挙げられる。
芳香族炭化水素基としては、フェニル基、１－ナフチル基、２－ナフチル基、２－メチルフェニル基、３－メチルフェニル基、４－メチルフェニル基、４－エチルフェニル基、４－プロピルフェニル基、４－イソプロピルフェニル基、４－ブチルフェニル基、４－ｔ－ブチルフェニル基、４－ヘキシルフェニル基、４－シクロヘキシルフェニル基、アントリル基、ｐ－アダマンチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、ビフェニル基、フェナントリル基、２，６－ジエチルフェニル基、２－メチル－６－エチルフェニル基等のアリール基等が挙げられる。
これらを組み合わせることにより形成される基としては、アルキル－シクロアルキル基、シクロアルキル－アルキル基、アラルキル基（例えば、フェニルメチル基、１－フェニルエチル基、２－フェニルエチル基、１－フェニル－１－プロピル基、１－フェニル－２－プロピル基、２－フェニル－２－プロピル基、３－フェニル－１－プロピル基、４－フェニル－１－ブチル基、５－フェニル－１－ペンチル基、６－フェニル－１－ヘキシル基等）等が挙げられる。
アルコキシ基としては、メトキシ基、エトキシ基等が挙げられる。
アシル基としては、アセチル基、プロパノイル基、ベンゾイル基、シクロヘキサンカルボニル基等が挙げられる。
アシルオキシ基としては、上記アシル基にオキシ基（－Ｏ－）が結合した基等が挙げられる。
アルコキシカルボニル基としては、上記アルコキシ基にカルボニル基（－ＣＯ－）が結合した基等が挙げられる。
ハロゲン原子としては、フッ素原子、塩素原子、臭素原子等が挙げられる。
Ｒ^D1及びＲ^D2は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１０のシクロアルキル基、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、炭素数２～４のアルコキシカルボニル基、ニトロ基又はハロゲン原子が好ましい。
ｍ’及びｎ’は、それぞれ独立に、０～２のいずれかの整数であることが好ましく、０であることがより好ましい。ｍ’が２以上の場合、複数のＲ^D1は同一であっても異なってもよく、ｎ’が２以上の場合、複数のＲ^D2は同一であっても異なってもよい。

[In the formula (D),
R ^D1 and R ^D2 are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, and a carbon number represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms;
m' and n' each independently represent an integer of 0 to 4, and when m' is 2 or more, the plurality of R ^D1 may be the same or different, and n' is 2 or more , the plurality of R ^D2 may be the same or different. ]
Examples of hydrocarbon groups for R ^D1 and R ^D2 include chain hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, groups formed by combining these groups, and the like.
Chain hydrocarbon groups include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group and nonyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and may be saturated or unsaturated. cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group and cyclododecyl group; norbornyl group; adamantyl group;
Aromatic hydrocarbon groups include phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group and 4-propylphenyl group. , 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group , mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group and the like.
Groups formed by combining these groups include alkyl-cycloalkyl groups, cycloalkyl-alkyl groups, aralkyl groups (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.).
The alkoxy group includes a methoxy group, an ethoxy group, and the like.
The acyl group includes acetyl group, propanoyl group, benzoyl group, cyclohexanecarbonyl group and the like.
Examples of the acyloxy group include groups in which an oxy group (--O--) is bonded to the above acyl group.
Examples of the alkoxycarbonyl group include groups in which a carbonyl group (--CO--) is bonded to the above alkoxy group.
A fluorine atom, a chlorine atom, a bromine atom etc. are mentioned as a halogen atom.
R ^D1 and R ^D2 each independently represent an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, and an acyl group having 2 to 4 carbon atoms. Acyloxy groups having 2 to 4 carbon atoms, alkoxycarbonyl groups having 2 to 4 carbon atoms, nitro groups or halogen atoms are preferred.
Each of m' and n' is preferably an integer of 0 to 2, more preferably 0. When m' is 2 or more, multiple R ^D1 may be the same or different, and when n' is 2 or more, multiple R ^D2 may be the same or different.

More specific examples include the following salts.

<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 a compound (I), a resin (A), an acid generator (B), and, if necessary, a resin other than the resin (A), a solvent (E), and a quencher (C). and 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 and the solubility of the resin 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 the substrate include an inorganic substrate such as a silicon wafer and an organic substrate having a resist film or the like formed on the surface thereof. Before applying the resist composition, the substrate may be washed, and 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. Moreover, 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 the present 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. A chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the composition after heating. Moreover, before the development, the steps of applying a resist composition, drying, exposing, and heating may be repeatedly performed on the exposed composition layer.
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 development temperature is preferably, for example, 5 to 60° C., and the development time is preferably, for example, 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, particularly ArF It is suitable as a resist composition for excimer laser exposure and useful for fine processing 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)

Further, 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－１－ａ）で表される化合物２．６０部、ジメチルホルムアミド２０部及びジイソプロピルエチルアミン１．５５部を混合し、２３℃で３０分攪拌した後、５℃まで冷却した。得られた混合物に、式（Ｉ－１－ｂ）で表される化合物１．３２部を滴下した後、５０℃まで昇温し、５０℃で３時間攪拌した。得られた混合物を２３℃まで冷却した後、イオン交換水２０部及びｔｅｒｔ－ブチルメチルエーテル４０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。得られた有機層に、５％シュウ酸水溶液３０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。この洗浄の操作を５回行った。得られた有機層に、イオン交換水４０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。この水洗の操作を５回行った。得られた有機層を濃縮し、濃縮マスをカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝５／１）分取することにより、式（Ｉ－１）で表される化合物１．４３部を得た。
ＭＡＳＳ（質量分析）：３５７．１［Ｍ＋Ｈ］^＋ Synthesis Example 1: Synthesis of Compound Represented by Formula (I-1)

2.60 parts of the compound represented by formula (I-1-a), 20 parts of dimethylformamide and 1.55 parts of diisopropylethylamine were mixed, stirred at 23°C for 30 minutes, and then cooled to 5°C. After 1.32 parts of the compound represented by the formula (I-1-b) was added dropwise to the obtained mixture, the temperature was raised to 50° C. and the mixture was stirred at 50° C. for 3 hours. After cooling the resulting mixture to 23° C., 20 parts of ion-exchanged water and 40 parts of tert-butyl methyl ether were added, stirred at 23° C. for 30 minutes, and separated to obtain an organic layer. 30 parts of a 5% aqueous oxalic acid solution was added to the obtained organic layer, and the mixture was stirred at 23° C. for 30 minutes and separated to obtain an organic layer. This washing operation was performed 5 times. 40 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23° C. for 30 minutes and separated to obtain an organic layer. This washing operation was performed 5 times. The obtained organic layer is concentrated, and the concentrated mass is collected by column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=5/1). Thus, 1.43 parts of the compound represented by formula (I-1) was obtained.
MASS: 357.1 [M+H] ⁺

式（Ｉ－１－ａ）で表される化合物２．６０部及びクロロホルム４０部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、式（Ｉ－２－ｂ）で表される化合物１．６２部を添加し、さらに、５０℃で２時間攪拌した。得られた混合溶液に、式（Ｉ－２－ｃ）で表される化合物１．６８部を添加し、さらに、５０℃で３時間攪拌した後、２３℃まで冷却した。得られた混合物に、５％シュウ酸水溶液２０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。得られた有機層にイオン交換水２０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５回繰り返した。得られた有機層を濃縮し、濃縮混合物をカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝１０／１）を用いて分取することにより、式（Ｉ－２）で表される化合物２．８８部を得た。
ＭＡＳＳ（質量分析）：４５５．１［Ｍ＋Ｈ］^＋ Synthesis Example 2: Synthesis of Compound Represented by Formula (I-2)

2.60 parts of the compound represented by formula (I-1-a) and 40 parts of chloroform were mixed and stirred at 23° C. for 30 minutes. 1.62 parts of the compound represented by the formula (I-2-b) was added to the obtained mixed solution, and the mixture was further stirred at 50° C. for 2 hours. To the obtained mixed solution, 1.68 parts of the compound represented by the formula (I-2-c) was added, further stirred at 50°C for 3 hours, and then cooled to 23°C. After adding 20 parts of a 5% aqueous oxalic acid solution to the resulting mixture and stirring at 23° C. for 30 minutes, the mixture was separated and the organic layer was taken out. After adding 20 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was passed through a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=10/1). By fractionating, 2.88 parts of the compound represented by formula (I-2) was obtained.
MASS: 455.1 [M+H] ⁺

式（Ｉ－１－ａ）で表される化合物２．６０部、ジメチルホルムアミド２０部及びジイソプロピルエチルアミン１．５５部を混合し、２３℃で３０分攪拌した後、５℃まで冷却した。得られた混合物に、式（Ｉ－１７－ｂ）で表される化合物１．８２部を滴下した後、５０℃まで昇温し、５０℃で３時間攪拌した。得られた混合物を２３℃まで冷却した後、イオン交換水２０部及びｔｅｒｔ－ブチルメチルエーテル４０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。得られた有機層に、５％シュウ酸水溶液３０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。この洗浄の操作を５回行った。得られた有機層に、イオン交換水４０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。この水洗の操作を５回行った。得られた有機層を濃縮し、濃縮マスをカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝５／１）分取することにより、式（Ｉ－１７）で表される化合物１．７８部を得た。
ＭＡＳＳ（質量分析）：４０７．１［Ｍ＋Ｈ］^＋ Synthesis Example 3: Synthesis of Compound Represented by Formula (I-17)

2.60 parts of the compound represented by formula (I-1-a), 20 parts of dimethylformamide and 1.55 parts of diisopropylethylamine were mixed, stirred at 23°C for 30 minutes, and then cooled to 5°C. After 1.82 parts of the compound represented by the formula (I-17-b) was added dropwise to the obtained mixture, the temperature was raised to 50°C and the mixture was stirred at 50°C for 3 hours. After cooling the resulting mixture to 23° C., 20 parts of ion-exchanged water and 40 parts of tert-butyl methyl ether were added, stirred at 23° C. for 30 minutes, and separated to obtain an organic layer. 30 parts of a 5% aqueous oxalic acid solution was added to the obtained organic layer, and the mixture was stirred at 23° C. for 30 minutes and separated to obtain an organic layer. This washing operation was performed 5 times. 40 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23° C. for 30 minutes and separated to obtain an organic layer. This washing operation was performed 5 times. The obtained organic layer is concentrated, and the concentrated mass is collected by column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=5/1). Thus, 1.78 parts of the compound represented by formula (I-17) was obtained.
MASS: 407.1 [M+H] ⁺

式（Ｉ－１－ａ）で表される化合物２．６０部、ジメチルホルムアミド２０部及びジイソプロピルエチルアミン１．５５部を混合し、２３℃で３０分攪拌した後、５℃まで冷却した。得られた混合物に、式（Ｉ－１８－ｂ）で表される化合物２．３２部を滴下した後、５０℃まで昇温し、５０℃で３時間攪拌した。得られた混合物を２３℃まで冷却した後、イオン交換水２０部及びｔｅｒｔ－ブチルメチルエーテル４０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。得られた有機層に、５％シュウ酸水溶液３０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。この洗浄の操作を５回行った。得られた有機層に、イオン交換水４０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。この水洗の操作を５回行った。得られた有機層を濃縮し、濃縮マスをカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝５／１）分取することにより、式（Ｉ－１８）で表される化合物１．６８部を得た。
ＭＡＳＳ（質量分析）：４５７．１［Ｍ＋Ｈ］^＋ Synthesis Example 4: Synthesis of Compound Represented by Formula (I-18)

2.60 parts of the compound represented by formula (I-1-a), 20 parts of dimethylformamide and 1.55 parts of diisopropylethylamine were mixed, stirred at 23°C for 30 minutes, and then cooled to 5°C. After 2.32 parts of the compound represented by the formula (I-18-b) was added dropwise to the obtained mixture, the temperature was raised to 50°C and the mixture was stirred at 50°C for 3 hours. After cooling the resulting mixture to 23° C., 20 parts of ion-exchanged water and 40 parts of tert-butyl methyl ether were added, stirred at 23° C. for 30 minutes, and separated to obtain an organic layer. 30 parts of a 5% aqueous oxalic acid solution was added to the obtained organic layer, and the mixture was stirred at 23° C. for 30 minutes and separated to obtain an organic layer. This washing operation was performed 5 times. 40 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23° C. for 30 minutes and separated to obtain an organic layer. This washing operation was performed 5 times. The obtained organic layer is concentrated, and the concentrated mass is collected by column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=5/1). Thus, 1.68 parts of the compound represented by formula (I-18) was obtained.
MASS: 457.1 [M+H] ⁺

式（Ｉ－１－ａ）で表される化合物２．６０部、ジメチルホルムアミド２０部及びジイソプロピルエチルアミン１．５５部を混合し、２３℃で３０分攪拌した後、５℃まで冷却した。得られた混合物に、式（Ｉ－１９－ｂ）で表される化合物２．８２部を滴下した後、５０℃まで昇温し、５０℃で３時間攪拌した。得られた混合物を２３℃まで冷却した後、イオン交換水２０部及びｔｅｒｔ－ブチルメチルエーテル４０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。得られた有機層に、５％シュウ酸水溶液３０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。この洗浄の操作を５回行った。得られた有機層に、イオン交換水４０部を加え、２３℃で３０分間攪拌し、分液することにより有機層を得た。この水洗の操作を５回行った。得られた有機層を濃縮し、濃縮マスをカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝５／１）分取することにより、式（Ｉ－１９）で表される化合物１．６６部を得た。
ＭＡＳＳ（質量分析）：５０７．１［Ｍ＋Ｈ］^＋ Synthesis Example 5: Synthesis of Compound Represented by Formula (I-19)

2.60 parts of the compound represented by formula (I-1-a), 20 parts of dimethylformamide and 1.55 parts of diisopropylethylamine were mixed, stirred at 23°C for 30 minutes, and then cooled to 5°C. After 2.82 parts of the compound represented by the formula (I-19-b) was added dropwise to the resulting mixture, the temperature was raised to 50°C and the mixture was stirred at 50°C for 3 hours. After cooling the resulting mixture to 23° C., 20 parts of ion-exchanged water and 40 parts of tert-butyl methyl ether were added, stirred at 23° C. for 30 minutes, and separated to obtain an organic layer. 30 parts of a 5% aqueous oxalic acid solution was added to the obtained organic layer, and the mixture was stirred at 23° C. for 30 minutes and separated to obtain an organic layer. This washing operation was performed 5 times. 40 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23° C. for 30 minutes and separated to obtain an organic layer. This washing operation was performed 5 times. The obtained organic layer is concentrated, and the concentrated mass is collected by column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=5/1). Thus, 1.66 parts of the compound represented by formula (I-19) was obtained.
MASS: 507.1 [M+H] ⁺

Synthesis of Resin Compounds (monomers) used for synthesizing resin (A) are shown below. Hereinafter, these compounds are referred to as "monomer (a1-1-3)" and the like according to their formula numbers.

Synthesis Example 6: Synthesis of Resin A1 As monomers, monomer (a1-1-3), monomer (a1-2-6), monomer (a2-1-1) and monomer (a3-4-2) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-6):monomer (a2-1-1):monomer (a3-4-2)] was 45:14:2.5:38. 5, and propylene glycol monomethyl ether acetate in an amount 1.5 times the total amount of monomers was added to obtain a solution. To this solution, 1 mol % and 3 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively, and these were heated at 73° C. for about 5 hours. 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 is again dissolved in propylene glycol monomethyl ether acetate, the resulting solution is poured into a methanol/water mixed solvent to precipitate the resin, and the resin is filtered. Resin A1 with a molecular weight of 7.8×10 ³ was obtained with a yield of 69%. This resin A1 has the following structural units.

Synthesis Example 7 Synthesis of Resin X1 Monomer (a4-1-7) was used as a monomer, and methyl isobutyl ketone was added in an amount 1.5 times the total amount of monomers to form a solution. To this solution, 0.7 mol % and 2.1 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively. Heated for about 5 hours. The resulting reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate the resin, which was filtered to obtain Resin X1 having a weight average molecular weight of 1.7×10 ⁴ with a yield of 77%. This resin X1 has the following structural units.

<Preparation of resist composition>
As shown in Table 1, a resist composition was prepared by mixing the following components and filtering the resulting mixture through a fluororesin filter having a pore size of 0.2 μm.

＜酸発生剤＞
Ｂ１－２１：式（Ｂ１－２１）で表される塩
Ｂ１－２２：式（Ｂ１－２２）で表される塩

＜クエンチャー（Ｃ）＞
Ｄ１：（東京化成工業（株）製）

＜溶剤＞
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 <Resin>
A1, X1: Resin A1, Resin X1
<Compound (I)>
I-1: compound represented by formula (I-1) I-2: compound represented by formula (I-2) I-17: compound represented by formula (I-17) I-18: formula Compound represented by (I-18) I-19: Compound represented by Formula (I-19) <Compound (IX)>
IX-1:

<Acid Generator>
B1-21: a salt represented by the formula (B1-21) B1-22: a salt represented by the formula (B1-22)

<Quencher (C)>
D1: (manufactured by Tokyo Chemical Industry Co., Ltd.)

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

<Focus margin evaluation (DOF)>
An organic antireflection film composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer and baked at 205° C. for 60 seconds to form an organic film having a thickness of 78 nm. An antireflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness of the composition layer after drying (pre-baking) was 85 nm. The silicon wafer coated with the resist composition was prebaked for 60 seconds on a direct hot plate at the temperature indicated in the "PB" column of Table 1 to form a composition layer on the silicon wafer. An ArF excimer stepper for immersion exposure [XT: 1900Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light] is used for the composition layer formed on the silicon wafer, and the exposure dose is stepped. A line-and-space pattern was immersion exposed by changing the Ultrapure water was used as the liquid immersion medium. After the exposure, post-exposure baking was performed for 60 seconds on a hot plate at the temperature listed in the "PEB" column of Table 1. Next, the composition layer after heating was subjected to puddle development at 23° C. for 60 seconds using a 2.38% tetramethylammonium hydroxide aqueous solution as a developer to produce a resist pattern.

In each resist pattern film obtained, the effective sensitivity was defined as the exposure dose at which the line-and-space pattern of 40 nm was 1:1.

A resist pattern was produced in the same manner as described above, except that exposure was performed while changing the focus stepwise in terms of effective sensitivity. In the obtained resist pattern, the DOF (nm) was defined as the focus range where the width of the line-and-space pattern was 40 nm±5% (38 to 42 nm). Table 2 shows the results.

From the above results, it can be seen that a resist pattern with a good focus margin (DOF) can be produced using a resist composition containing the compound of the present invention.

INDUSTRIAL APPLICABILITY A resist composition containing the compound of the present invention can obtain a resist pattern having a good focus margin (DOF).

Claims (6)

A resist composition containing a compound represented by formula (I), a resin having an acid-labile group, and an acid generator.

[in the formula (I),
Ring W represents an alicyclic hydrocarbon group containing an ether bond having 3 to 36 carbon atoms.
L ¹ represents a single bond or an optionally substituted alkanediyl group having 1 to 6 carbon atoms.
R ¹ is *-R ¹⁰ , *-CO-R ¹⁰ , *-CO-OR ¹⁰ , *-L ² -CO-O-R ¹⁰ or *-CO-OL ² -CO-O- represents R ¹⁰ and * represents the binding site with -O-.
R ¹⁰ represents a base labile group.
L ² represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms.
R ² represents *-L ¹ -OR ¹ , *-L ³ (-OR ¹ ) ₂ or a group represented by formula (R ² -1), * is a bond to ring W represents the part.

L ³ represents an optionally substituted alkanetriyl group having 1 to 6 carbon atoms.
R ^ab1 and R ^ab2 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group having 3 to 20 carbon ^{atoms ;} form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded, and —CH ₂ — contained in the alkyl group and the alicyclic hydrocarbon group is —O— or —CO - may be replaced.
m2 represents an integer of 0 to 6; when m2 is 1 or more, the plurality of L ^1s and the plurality of R ^1s may be the same or different; when m2 is 2 or more, A plurality of R ² may be the same or different from each other.
R ³ represents a halogen atom, a hydroxy group, a haloalkyl group having 1 to 12 carbon atoms or an alkyl group having 1 to 12 carbon atoms, and —CH ₂ — contained in the alkyl group is —O— or —CO—; may be replaced. Two ^R3 's may together form a group having an acetal ring structure.
m3 represents an integer of 0 to 6, and when m3 is ² or more, multiple R3's may be the same or different. ] 2. The resist composition according to claim 1, wherein the base ^- labile group of R10 is a group represented by formula (1b).

[In the formula (1b), R ^ba1 and R ^ba2 each independently represent a hydrogen atom, a fluorine atom or a fluorine atom-containing alkyl group having 1 to 6 carbon atoms.
R ^ba3 represents a fluorine atom or a fluorine atom-containing alkyl group having 1 to 6 carbon atoms.
* represents a binding site. ] A group in which the resin having an acid-labile group comprises a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), and a structural unit represented by formula (a1-2). 3. The resist composition according to claim 1, comprising at least one selected from the above.

[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 the binding site with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom, a halogen atom or an optionally halogenated alkyl group having 1 to 6 carbon atoms.
R ^a02 , R ^a03 and R ^a04 are each independently an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or these Represents a combined group.
R ^a6 and R ^a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic group having 6 to 18 carbon atoms. It represents a hydrocarbon group or a group formed by combining these groups.
m1 represents any integer from 0 to 14;
n1 represents any integer from 0 to 10;
n1' represents an integer of 0 to 3; ] 4. The resist composition according to any one of claims 1 to 3, wherein the acid generator contains a salt represented by formula (B1).

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO— , a hydrogen atom contained in the divalent saturated hydrocarbon 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 24 carbon atoms, included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -S-, -SO ₂ - or -CO-.
Z1 ⁺ represents an organic cation. ] 5. The resist composition according to any one of claims 1 to 4, further comprising a salt that generates an acid weaker in acidity than the acid generated from the acid generator. (1) a step of applying the resist composition according to any one of claims 1 to 5 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: