JP7445396B2 - Salt, resist composition, and method for producing resist pattern - Google Patents

Description

The present invention relates to a salt used in semiconductor microfabrication, a resist composition, and a method for producing a resist pattern.

特許文献２には、下記式で表される塩が記載されている。

特許文献３には、下記式で表される塩の合成方法が記載されている。

（式（１）中、Ｒ^１は、炭素数１～２０のアルキル基、炭素数３～２０の１価の脂環式炭化水素基、炭素数６～１５のアリール基又は炭素数４～１５のヘテロアリール基である。Ｒ^２は、２価の連結基である。Ｒ^ｆは、フッ素原子又は炭素数１～３０のフッ素化アルキル基である。Ｍ^＋は、１価のカチオンである。ｎ１及びｎ２は、それぞれ独立して、０又は１である。） Patent Document 1 describes a salt represented by the following formula.

Patent Document 2 describes a salt represented by the following formula.

Patent Document 3 describes a method for synthesizing a salt represented by the following formula.

(In formula (1), R ¹ is an alkyl group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, or an aryl group having 4 to 15 carbon atoms. is a heteroaryl group. R ² is a divalent linking group. R ^f is a fluorine atom or a fluorinated alkyl group having 1 to 30 carbon atoms. M ⁺ is a monovalent cation. n1 and n2 are each independently 0 or 1.)

Japanese Patent Application Publication No. 2013-114085 WO2012/096264 pamphlet WO2011/093280 pamphlet

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

［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２～４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は互いに同一であっても異なってもよい。］

［式（Ｉ）中、
Ｒ^３及びＲ^４は、それぞれ独立に、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す。
ｚは、０～６のいずれかの整数を表し、ｚが２以上のとき、複数のＲ^３及びＲ^４は互いに同一であっても異なってもよい。
Ｘ¹は、＊－ＣＯ－Ｏ－、＊－Ｏ－ＣＯ－、＊－Ｏ－ＣＯ－Ｏ－又は＊－Ｏ－（＊はＣ（Ｒ^３）（Ｒ^４）又はＣＨＣＦ_３との結合部位を表す。）を表す。
Ｌ¹は、単結合又は炭素数１～２８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－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ｒ^５は、置換基を有してもよい炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ｚ⁺は有機カチオンを表す。］
［２］ｚが、１又は２である［１］記載のレジスト組成物。
［３］Ｘ¹が、＊－ＣＯ－Ｏ－又は＊－Ｏ－ＣＯ－（但し、＊は、Ｃ（Ｒ¹）（Ｒ²）又はＣ（Ｑ¹）（Ｑ²）との結合位を表す。）である［１］又は［２］記載のレジスト組成物。
［４］Ｌ¹が、単結合、アルカンジイル基（但し、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。）又はアルカンジイル基と脂環式飽和炭化水素基とを組み合わせてなる基とを組み合わせてなる基（但し、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く、該脂環式飽和炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。）である［１］～［３］のいずれかに記載のレジスト組成物。
［５］酸不安定基を有する構造単位が、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種である［１］～［４］のいずれかに記載のレジスト組成物。

［式（ａ１－１）及び式（ａ１－２）中、
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の整数を表し、＊は－ＣＯ－との結合部位を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組合せた基を表す。
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。］
［６］式（Ｉ）で表される塩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］～［５］のいずれかに記載のレジスト組成物。
［７］（１）［１］～［６］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。
［８］式（Ｉａ）で表される塩。

［式（Ｉａ）中、
Ｒ^３及びＲ^４は、それぞれ独立に、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す。
ｚは、０～６のいずれかの整数を表し、ｚが２以上のとき、複数のＲ^３及びＲ^４は互いに同一であっても異なってもよい。
Ｘ¹は、＊－ＣＯ－Ｏ－、＊－Ｏ－ＣＯ－、＊－Ｏ－ＣＯ－Ｏ－又は＊－Ｏ－（＊はＣ（Ｒ^３）（Ｒ^４）又はＣＨＣＦ_３との結合部位を表す。）を表す。
Ｌ¹は、単結合又は炭素数１～２８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－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ｒ^5aは、水酸基を有する炭素数３～１８の脂環式炭化水素基を表すか、又は、置換基を有してもよい炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ_２－の少なくとも一つは、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わる。
Ｚ⁺は有機カチオンを表す。］ The present invention includes the following inventions.
[1] A resist composition containing a resin containing a structural unit represented by formula (a2-A) and a structural unit having an acid-labile group, and a salt represented by formula (I).

[In 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, hydroxy group, alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl Represents an oxy 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 is bonded.
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 any integer from 0 to 4. When mb is any integer of 2 or more, a plurality of R ^a51 's may be the same or different. ]

[In formula (I),
R ³ and R ⁴ each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents any integer from 0 to 6, and when z is 2 or more, the plurality of R ³ and R ⁴ may be the same or different.
X ¹ is *-CO-O-, *-O-CO-, *-O-CO-O- or *-O- (* is a bonding site with C(R ³ )(R ⁴ ) or CHCF ₃ ).
L ¹ represents a single bond or a divalent saturated hydrocarbon group having 1 to 28 carbon atoms, and -CH ₂ - contained in the saturated hydrocarbon group is -O-, -S-, -SO ₂ - or -CO- may be substituted.
R ⁵ represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and -CH ₂ - contained in the alicyclic hydrocarbon group is -O-, -S- , -SO ₂ - or -CO-.
Z ⁺ represents an organic cation. ]
[2] The resist composition according to [1], wherein z is 1 or 2.
[3] X ¹ is *-CO-O- or *-O-CO- (where * represents the bonding position with C(R ¹ )(R ² ) or C(Q ¹ )(Q ² ) The resist composition according to [1] or [2], which is
[4] L ¹ is a single bond, an alkanediyl group (however, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-), or an alkanediyl group and a fatty acid group. A group formed by combining a group formed by combining a cyclic saturated hydrocarbon group (However, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-, -CH ₂ - contained in the cyclic saturated hydrocarbon group may be replaced with -O-, -S-, -SO ₂ - or -CO-. The resist composition according to claim 1.
[5] The structural unit having an acid-labile group is at least one type selected from the group consisting of the structural unit represented by formula (a1-1) and the structural unit represented by formula (a1-2) [ 1] to [4].

[In formula (a1-1) and formula (a1-2),
L ^a1 and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, k1 represents an integer from 1 to 7, and * represents a bond with -CO- Represents a part.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents any integer from 0 to 14.
n1 represents any integer from 0 to 10.
n1' represents any integer from 0 to 3. ]
[6] The resist composition according to any one of [1] to [5], further containing a salt that generates an acid with weaker acidity than the acid generated from the salt represented by formula (I).
[7] (1) Applying the resist composition according to any one of [1] to [6] onto a substrate,
(2) drying the applied composition to form a composition layer;
(3) exposing the composition layer to light;
(4) a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.
A method for manufacturing a resist pattern including:
[8] Salt represented by formula (Ia).

[In formula (Ia),
R ³ and R ⁴ each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents any integer from 0 to 6, and when z is 2 or more, the plurality of R ³ and R ⁴ may be the same or different.
X ¹ is *-CO-O-, *-O-CO-, *-O-CO-O- or *-O- (* is a bonding site with C(R ³ )(R ⁴ ) or CHCF ₃ ).
L ¹ represents a single bond or a divalent saturated hydrocarbon group having 1 to 28 carbon atoms, and -CH ₂ - contained in the saturated hydrocarbon group is -O-, -S-, -SO ₂ - or -CO- may be substituted.
R ^5a represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms having a hydroxyl group, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent; At least one of -CH ₂ - contained in the cyclic hydrocarbon group is replaced with -O-, -S-, -SO ₂ - or -CO-.
Z ⁺ represents an organic cation. ]

By using the resist composition of the present invention, a resist pattern can be manufactured with good CD uniformity (CDU).

In this specification, unless otherwise specified, "(meth)acrylate" means "at least one selected from the group consisting of acrylate and methacrylate." Notations such as "(meth)acrylic acid" and "(meth)acryloyl" have similar meanings. When a structural unit having "CH ₂ = C(CH ₃ )-CO-" or "CH ₂ = CH-CO-" is exemplified, a structural unit having both groups is similarly exemplified. shall be taken as a thing. A "combined group" means a group in which two or more of the exemplified groups are bonded together with their valences appropriately changed. Moreover, when stereoisomers exist, all stereoisomers are included.
As used herein, "solid content of the resist composition" refers to 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 resin containing a structural unit represented by formula (a2-A) and a structural unit having an acid-labile group (hereinafter sometimes referred to as resin (A)), and a resin (hereinafter sometimes referred to as resin (A)), and a resin containing a structural unit represented by formula (a2-A) and a structural unit having an acid labile group; ) (hereinafter sometimes referred to as "salt (I)").
Further, the resist composition preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") and/or a solvent (hereinafter sometimes referred to as "solvent (E)").

<Resin (A)>
The resin (A) includes a structural unit represented by formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)").
<Structural unit (a2-A)>
In formula (a2-A), examples of the halogen atom for R ^a50 include a fluorine atom, a chlorine atom, a bromine atom, and the like.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R ^a50 include 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-tetrafluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group , perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3 -hexafluorobutyl group, 2,2,3,3,4,4-hexafluorobutyl group, 2,2,3,3,4,4,4-peptafluorobutyl group, butyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl group , 2-(perfluorobutyl)ethyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, 1,1,2,2,3,3 , 4,4,5,5-decafluorohexyl group, 2,2,3,3,4,4,5,5,6,6-decafluorohexyl group, 1,1,2,2,3,3 , 4,4,5,5,6,6-dodecafluorohexyl group and perfluorohexyl group.
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, and even more preferably a hydrogen atom or a methyl group.
Examples of the alkyl group for R ^a51 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group.
Examples of the alkoxy group for R ^a51 include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, and tert-butoxy group. An alkoxy group having 1 to 4 carbon atoms is preferred, a methoxy group or an ethoxy group is more preferred, and a methoxy group is even more preferred.
Examples of the alkylcarbonyl group for R ^a51 include an acetyl group, a propionyl group, a butyryl group, and the like.
Examples of the alkylcarbonyloxy group for R ^a51 include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
R ^a51 is preferably a methyl group.

^* -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 -. Among these, ^* -CO-O-, ^* -CO-O-A ^a52 -CO-O- or ^* -O-A ^a52 -CO-O- is preferred.

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

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

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

Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A No. 2010-204634 and JP-A No. 2012-12577.
Structural units (a2-A) include structural units represented by formulas (a2-2-1) to (a2-2-6) and formulas (a2-2-1) to (a2-2- Examples of the structural unit represented by 6) include a structural unit in which the methyl group corresponding to R ^a50 in structural unit (a2-A) is replaced with a hydrogen atom. The structural unit (a2-A) is a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), or a structural unit represented by formula (a2-2-6). In the structural unit represented by formula (a2-2-1), the structural unit represented by formula (a2-2-3) or the structural unit represented by formula (a2-2-6), Preferably, the structural unit (a2-A) is a structural unit in which the methyl group corresponding to R ^a50 is replaced with a hydrogen atom.

The content of the structural unit (a2-A) in the resin (A) is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, even more preferably 15 to 70 mol%, based on the total structural units. 65 mol%, even more preferably 20 to 65 mol%, even more preferably 20 to 50 mol%.
The structural unit (a2-A) can be included in the resin (A) by, for example, polymerizing using the structural unit (a1-4) described below and then treating it with an acid such as p-toluenesulfonic acid. . Further, 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.

The resin (A) contains a structural unit (hereinafter sometimes referred to as "structural unit (a1)") having an acid-labile group. Here, the acid-labile group means a group that has a leaving group and forms a hydrophilic group (for example, a hydroxy group or a carboxy group) when the leaving group is eliminated by contact with an acid.

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

［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の複素環基を形成し、該炭化水素基及び該複素環基に含まれる－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 preferred.

[In formula (1), R ^a1 , R ^a2 and R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof; Watermelon, R ^a1 and R ^a2 combine with each other to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
ma and na each independently represent 0 or 1, and at least one of ma and na represents 1.
* represents a 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. Alternatively, R ^a2' and R ^a3' combine with each other to form a heterocyclic group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and are included in the hydrocarbon group and the heterocyclic group. CH ₂ - may be replaced with -O- or -S-.
X represents an oxygen atom or a sulfur atom.
na' represents 0 or 1.
* represents a binding site. ]

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

Examples of the alkyl group for R ^a1 , R ^a2 and R ^a3 include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and the like.
The alicyclic hydrocarbon group in R ^a1 , R ^a2 and R ^a3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 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 groups combining an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, and a norbornyl group. Examples include ethyl group.
Preferably ma is 0 and na is 1.
Examples of --C(R ^a1 )(R ^a2 )(R ^a3 ) when R ^a1 and R ^a2 combine with each other to form an alicyclic hydrocarbon group include the following groups. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * represents a bonding 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 the hydrocarbon group for R ^a1' , R ^a2' and R ^a3' include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group and alicyclic hydrocarbon group include the same groups as those listed for R ^a1 , R ^a2 and R ^a3 .
Examples of aromatic hydrocarbon groups include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl group. and aryl groups such as phenanthryl group, 2,6-diethylphenyl group, and 2-methyl-6-ethylphenyl group.
Examples of the combined group include a group combining the above-mentioned alkyl group and an alicyclic hydrocarbon group (for example, a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aryl-cyclohexyl group such as a phenylcyclohexyl group, etc. .
When R ^a2' and R ^a3' combine with each other to form a heterocycle together with the carbon atom to which they are bonded and X, -C(R ^a1' ) (R ^a3' ) -X-R ^a2' is as follows. An example is the ring. * represents a binding site.

It is preferable that at least one of R ^a1' and R ^a2' is a hydrogen atom.
na' is preferably 0.

Examples of the group (1) include the following groups.
A group in which R ^a1 , R ^a2 and R ^a3 are alkyl groups, ma=0, and na=1 in formula (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 atom to which they are bonded, R ^a3 is an alkyl group, ma = 0, and na = 1. .
In formula (1), R ^a1 and R ^a2 are each independently an alkyl group, R ^a3 is an adamantyl group, ma=0, and na=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.

The 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 the (meth)acrylic monomers having an acid-labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferred. If 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、水素原子又はメチル基を表す。
Ｒ^a02、Ｒ^a03及びＲ^a04は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組み合わせた基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組合せることにより形成される基を表す。
ｍ１は０～１４のいずれかの整数を表す。
ｎ１は０～１０のいずれかの整数を表す。
ｎ１’は０～３のいずれかの整数を表す。］ As a structural unit derived from a (meth)acrylic monomer having group (1), a structural unit represented by formula (a1-0) (hereinafter sometimes referred to as structural unit (a1-0)), a formula ( a1-1) (hereinafter sometimes referred to as structural unit (a1-1)) or the structural unit represented by formula (a1-2) (hereinafter referred to as structural unit (a1-2)) ) may be mentioned. Preferably, it is at least one structural unit selected from the group consisting of structural unit (a1-1) and structural unit (a1-2). These may be used alone or in combination of two or more.

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

R ^a01 , R ^a4 and R ^a5 are preferably methyl groups.
L ^a01 , L ^a1 and L ^a2 are preferably an oxygen atom or *-O-(CH ₂ ) _k01 -CO-O- (however, k01 is preferably an integer of 1 to 4, more preferably is 1), more preferably an oxygen atom.
Examples of the alkyl group, alicyclic hydrocarbon group, and a combination thereof in R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 include the groups listed for R ^a1 , R ^a2 and R ^a3 in formula (1); Examples include groups similar to .
The number of carbon atoms in the alkyl group in R ^a02 , R ^a03 , and R ^a04 is preferably 1 to 6, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.
The number of carbon atoms in the alkyl group in R ^a6 and R ^a7 is preferably 1 to 6, more preferably a methyl group, an ethyl group, or an isopropyl group, and even more preferably an ethyl group or an isopropyl group.
The number of carbon atoms in the alicyclic hydrocarbon groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 is preferably 5 to 12, more preferably 5 to 10.
In the group that is a combination of an alkyl group and an alicyclic hydrocarbon group, it is preferable that the total carbon number of the alkyl group and alicyclic hydrocarbon group is 18 or less.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl 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, ethyl group, cyclohexyl group or adamantyl group.
R ^a6 and R ^a7 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, or an isopropyl group, and even more preferably an ethyl group or an isopropyl group.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1' is preferably 0 or 1.

The structural unit (a1-0) is, for example, a structural unit represented by any one of formulas (a1-0-1) to (a1-0-12) and R ^a01 in the structural unit (a1-0). Examples include structural units in which the corresponding methyl group is replaced with a hydrogen atom, and structural units represented by any of formulas (a1-0-1) to (a1-0-10) are preferred.

Examples of the structural unit (a1-1) include structural units derived from monomers described in JP-A No. 2010-204646. Among them, the structural unit represented by any one of formulas (a1-1-1) to formula (a1-1-4) and the methyl group corresponding to R ^a4 in the structural unit (a1-1) are replaced with a hydrogen atom. Structural units are preferred, and structural units represented by any of formulas (a1-1-1) to (a1-1-4) are more preferred.

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

When the resin (A) contains a structural unit (a1-0) and/or a structural unit (a1-1) and/or a structural unit (a1-2), the total content of these is the total structure of the resin (A). It is usually 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, even more preferably 25 to 80 mol%, and even more preferably It is 30 to 75 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２～４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。
ｌａは０～４のいずれかの整数を表す。ｌａが２以上である場合、複数のＲ^a33は互いに同一であっても異なってもよい。
Ｒ^a34及びＲ^a35はそれぞれ独立に、水素原子又は炭素数１～１２の炭化水素基を表し、Ｒ^a36は、炭素数１～２０の炭化水素基を表すか、Ｒ^a35及びＲ^a36は互いに結合してそれらが結合する－Ｃ－Ｏ－とともに炭素数２～２０の２価の炭化水素基を形成し、該炭化水素基及び該２価の炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－Ｓ－で置き換わってもよい。］ Examples of the structural unit having a group (2) in the structural unit (a1) include a structural unit 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, hydroxy group, alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl Represents an oxy group or a methacryloyloxy group.
la represents any integer from 0 to 4. When la is 2 or more, a plurality of R ^a33 's 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, and 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 divalent hydrocarbon group having 2 to 20 carbon atoms together with the -C-O- to which they are bonded, and the -CH ₂ - contained in the hydrocarbon group and the divalent hydrocarbon group is - May be replaced with O- or -S-. ]

Examples of the alkyl group for R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, and a hexyl group. 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.
Examples of the halogen atom for R ^a32 and R ^a33 include a fluorine atom, a chlorine atom, and a bromine atom.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 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, perfluorohexyl group, etc. can be mentioned.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group and hexyloxy group. Among these, an alkoxy group having 1 to 4 carbon atoms is preferred, a methoxy group or an ethoxy group is more preferred, and a methoxy group is even more preferred.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, and the like.
Examples of the hydrocarbon group in R ^a34 , R ^a35 and R ^a36 include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a combination thereof; Examples include the same groups as the alkyl group and alicyclic hydrocarbon group in R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 .
Examples of aromatic hydrocarbon groups include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl group. and aryl groups such as phenanthryl group, 2,6-diethylphenyl group, and 2-methyl-6-ethylphenyl group.
Examples of the combined group include a group combining the above-mentioned alkyl group and an alicyclic hydrocarbon group (for example, a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aryl-cyclohexyl group such as a phenylcyclohexyl group, etc. . 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 a combination thereof. can be mentioned.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
R ^a33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group.
la is preferably 0 or 1, and more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably an alkyl group or an alicyclic hydrocarbon group having 1 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 thereof. More preferably, it is an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and 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 having 6 to 10 carbon atoms.

--OC(R ^a34 )(R ^a35 )-O-R ^a36 in structural unit (a1-4) comes into contact with an acid (for example, p-toluenesulfonic acid) and is eliminated to form a hydroxy group.

Examples of the structural unit (a1-4) include structural units derived from monomers described in JP-A No. 2010-204646. Preferably, a structure in which the hydrogen atom corresponding to R ^a32 in the structural units represented by formulas (a1-4-1) to (a1-4-12) and the structural unit (a1-4) is replaced with a methyl group Examples include structural units, and more preferably structural units represented by formulas (a1-4-1) to (a1-4-5) and formula (a1-4-10), respectively.

When the resin (A) contains the structural unit (a1-4), the content thereof is preferably 10 to 95 mol%, and 15 to 90% by mole based on the total of all structural units of the resin (A). It is more preferably mol%, even more preferably 20 to 85 mol%, even more preferably 20 to 70 mol%, and particularly preferably 20 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。 Examples of the structural unit derived from the (meth)acrylic monomer having group (2) include the structural unit represented by formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)"). It will 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.

Examples of the halogen atom include a fluorine atom and a chlorine atom, with a fluorine atom 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 Examples include methyl group.
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.
It is preferable that one of L ⁵² and L ⁵³ is -O- and the other is -S-.
s1 is preferably 1.
s1' is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or *-CH ₂ -CO-O-.

Examples of the structural unit (a1-5) include structural units derived from monomers described in JP-A No. 2010-61117. Among these, structural units represented by formulas (a1-5-1) to (a1-5-4), respectively, are preferred, and structural units represented by formula (a1-5-1) or formula (a1-5-2) are preferred. 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). , 5 to 40 mol% is more preferable, and 5 to 30 mol% is even more preferable.

Moreover, as the structural unit (a1), the following structural units can also be mentioned.

When the resin (A) contains structural units such as the above formulas (a1-3-1) to (a1-3-7), the content thereof is 10% relative to the total structural units of the resin (A). -95 mol% is preferred, 15-90 mol% is more preferred, 20-85 mol% is even more preferred, 20-70 mol% is even more preferred, 20-60 mol% is even more preferred, 10-40 mol%. is particularly preferred.

The resin (A) may be a copolymer consisting only of the structural unit (a2-A) and the structural unit (a1), or may be a copolymer consisting of only the structural unit (a2-A) and the structural unit (a1), or one or more structural units other than the structural unit (a2-A) and the structural unit (a1). It may also be a copolymer containing. Structural units other than structural unit (a2-A) and structural unit (a1) include structural units other than structural units having an acid-labile group and having a halogen atom (hereinafter referred to as "structural unit (a4)"). ), a structural unit that does not have an acid-labile group (hereinafter sometimes referred to as "structural unit (s)"), a structural unit that has a non-eliminating hydrocarbon group (hereinafter referred to as "structural unit (a5)") ), a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as "structural unit (II)"), and other structural units derived from monomers known in the art.
When the resin (A) contains a structural unit represented by formula (a4) and/or (a5) described below (hereinafter sometimes referred to as "resin (AX)"), the structure in the resin (AX) of the present invention The content of the unit (I) is preferably 5 to 75 mol%, more preferably 10 to 70 mol%, and even more preferably It is 10 to 65 mol%, particularly preferably 10 to 60 mol%.

<Structural unit (s)>
The structural unit (s) is derived from a monomer that does not have an acid-labile group (hereinafter sometimes referred to as "monomer (s)"). As the monomer leading to the structural unit (s), monomers having no acid-labile groups 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 not having an acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and/or a structure having a lactone ring and not having an acid-labile group By using a resin having the unit (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group that the structural unit (a2) has 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 a high-energy beam such as a KrF excimer laser (248 nm), an electron beam, or EUV (ultra-ultraviolet light) is used as an exposure light source, the structural unit (a2) is It is preferable to use a structural unit (a2) having a phenolic hydroxy group. Furthermore, when using an ArF excimer laser (193 nm), etc., the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group, and it is more preferable to use the structural unit (a2-1) described below. preferable. The structural unit (a2) may contain one type alone or two or more types.

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。 Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include 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 binding 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 any integer from 0 to 10.

In formula (a2-1), L ^a3 is preferably -O-, -O-(CH ₂ ) _f1 -CO-O- (the f1 represents any integer from 1 to 4). , more preferably -O-.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 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 No. 2010-204646. A structural unit represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferable, and a structural unit represented by any one of formula (a2-1-1) to formula (a2-1-4) is preferable. The structural unit represented by the formula (a2-1-1) or the formula (a2-1-3) is more preferred.

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). The content is more preferably 1 to 35 mol%, still more preferably 2 to 20 mol%, and even more preferably 2 to 10 mol%.

<Structural unit (a3)>
The lactone ring possessed by the structural unit (a3) may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or may be a fused ring of a monocyclic lactone ring and another ring. But that's fine. Preferred examples include a γ-butyrolactone ring, an adamantane lactone 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、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。
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は互いに同一であってもよく、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 type of these may be contained alone, or two or more types 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 any integer from 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 * -O-L ^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 an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or 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 carboxyl 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 any integer from 0 to 3.
r1 represents any integer from 0 to 3.
w1 represents any integer from 0 to 8.
When p1, q1, r1 and/or w1 is 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 groups 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. It will be done.
Examples of the halogen atom for R ^a24 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group in 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. Examples include alkyl groups, more preferably methyl groups or ethyl groups.
Examples of the alkyl group having a halogen atom in R ^a24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluoro sec-butyl group, perfluoro tert-butyl group, perfluoropentyl group, perfluoro Examples include hexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group, and the like.
Examples of alkanediyl groups in L ^a8 and L ^a9 include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5 -diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, Examples include 4-diyl group and 2-methylbutane-1,4-diyl group.

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-, even 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, and even more preferably a hydrogen atom or a methyl group. It is.
R ^a25 is preferably a carboxy group, a cyano group or a methyl group.
L ^a7 is preferably -O- or *-O-L ^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 of 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 represent the same meanings as above.)

As the structural unit (a3), structures derived from monomers described in JP-A No. 2010-204646, monomers described in JP-A No. 2000-122294, and monomers described in JP-A No. 2012-41274 can be used. Units are listed. As the structural unit (a3), formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3- 1), a structural unit represented by formula (a3-3-2) and any one of formulas (a3-4-1) to formula (a3-4-12), and in the structural unit, formula (a3-1 ) ~ Structural units in which the methyl groups corresponding to R ^a18 , R ^a19 , R ^a20 and R ^a24 in formula (a3-4) are replaced with hydrogen atoms are preferred.

When the resin (A) contains the structural unit (a3), the total content thereof 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%.
In addition, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3), or the structural unit (a3-4) is relative to the total structural units of the resin (A), respectively. The amount is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, even more preferably 10 to 50 mol%.

［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のフッ素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、鎖式炭化水素基及び単環又は多環の脂環式炭化水素基、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)>
Examples of the structural unit (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 1 to 24 carbon atoms and having a fluorine atom, and -CH ₂ - contained in the saturated hydrocarbon group may be replaced with -O- or -CO. ]
Examples of the saturated hydrocarbon group represented by R ⁴² include a chain hydrocarbon group, a monocyclic or polycyclic alicyclic hydrocarbon group, and a group formed by combining these.

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。 Examples of chain 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. Can be mentioned. Examples of monocyclic or polycyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups. Examples include polycyclic alicyclic hydrocarbon groups such as (* represents a bonding site).

Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, such as -alkanediyl group- Examples include alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, -alkanediyl group-alicyclic 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２価の脂肪族飽和炭化水素基を表す。
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。
Ｒ⁶は、水素原子又はフッ素原子を表す。］ The structural unit (a4) is at least one selected from the group consisting of formula (a4-0), formula (a4-1), formula (a4-2), formula (a4-3) and formula (a4-4). Examples include structural units represented by one.

[In formula (a4-0),
R ⁵⁴ represents a hydrogen atom or a methyl group.
L ^4a represents a single bond or a divalent aliphatic saturated hydrocarbon 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.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

Examples of the divalent aliphatic saturated hydrocarbon group in L ^4a include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, and ethane-1 , 1-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, and 2-methylpropane-1,2-diyl group, etc. and alkanediyl groups.
The perfluoroalkanediyl group in L ^3a includes a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, and a perfluoropropane group. -2,2-diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane -2,2-diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane -1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane -2,2-diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like.
Examples of the perfluorocycloalkanediyl group for L ^3a include 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 perfluoroalkanediyl group having 1 to 6 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

Examples of the structural unit (a4-0) include the 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価の脂肪族炭化水素基を表す。
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。〕
＊は結合部位を表し、右側の＊が－Ｏ－ＣＯ－Ｒ^a42との結合部位を表す。］

[In formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH ₂ - contained in the saturated hydrocarbon group is replaced with -O- or -CO-. It's okay.
A ^a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent 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 a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a single bond or a substituent.
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. ]
* represents a binding site, and the * on the right side represents a binding site with -O-CO-R ^a42 . ]

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

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。 Examples of chain 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. Can be mentioned. Examples of monocyclic or polycyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups. Examples include polycyclic alicyclic hydrocarbon groups such as (* represents a bonding site).

Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, such as -alkanediyl group- Examples include alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, -alkanediyl group-alicyclic 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（＊はＲ^a42との結合部位を表す。）を表す。
Ａ^a45は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
＊は結合部位を表す。］
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の脂肪族炭化水素基を表す。 Examples of the substituent that R ^a42 may have include at least one selected from the group consisting of a halogen atom and a group represented by formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred.

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

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 aliphatic hydrocarbon groups in A ^a45 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 Alkyl groups such as octadecyl groups;
Monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; and decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents the bonding site) ) and other polycyclic alicyclic hydrocarbon groups.

Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, such as -alkanediyl group- Examples thereof include alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

R ^a42 is preferably a saturated hydrocarbon group which may have a halogen atom, more preferably a saturated hydrocarbon group having an alkyl group having a halogen atom and/or 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, and still more preferably a group having 1 to 1 carbon atoms. 6 perfluoroalkyl group, particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl 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 having 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価の脂肪族炭化水素基を表す。
Ｘ^a44は、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＡ^a46との結合部位を表す。）を表す。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
ただし、Ａ^a46、Ａ^a47及びＸ^a44の炭素数の合計は１８以下であり、Ａ^a46及びＡ^a47のうち、少なくとも一方は、少なくとも１つのハロゲン原子を有する。
＊はカルボニル基との結合部位を表す。］ When R ^a42 is a saturated hydrocarbon having a group represented by formula (a-g3), R ^a42 is more preferably a group represented by formula (a-g2).

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

The aliphatic hydrocarbon group of A ^a46 preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.
The aliphatic 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 preferable structure of the group represented by formula (a-g2) is the following structure (* represents a bonding site with a carbonyl group).

As the alkanediyl group in A ^a41 , methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group Linear alkanediyl groups such as; propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, Examples include branched alkanediyl groups such as 2-methylbutane-1,4-diyl group.
Examples of the substituent 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 even more preferably an ethylene group.

The divalent saturated hydrocarbon groups represented by A ^a42 , A ^a43 and A ^a44 in the group represented by formula (a-g1) include linear or branched alkanediyl groups and monocyclic or polycyclic divalent hydrocarbon groups. Examples thereof include an alicyclic hydrocarbon group, and a divalent aliphatic hydrocarbon group formed by combining an alkanediyl group and a divalent alicyclic hydrocarbon group. 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, Examples include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
Examples of the substituent for the divalent saturated hydrocarbon group represented by A ^a42 , A ^a43 and A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
Preferably, s is 0.

Examples of the group represented by formula (a-g2) 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 ** represents a binding site with -O-CO-R ^a42 .

As the structural unit represented by formula (a4-1), the methyl group corresponding to R ^a41 in the structural unit shown below and the structural unit represented by formula (a4-1) in the following structural unit is a hydrogen atom. Examples include substituted structural units.

［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。］ The structural unit represented by formula (a4-1) is preferably a structural unit represented by formula (a4-2).

[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 having a fluorine atom.
However, the upper limit of the total carbon number of L ⁴⁴ and R ^f6 is 21. ]

Examples of the alkanediyl group having 1 to 6 carbon atoms for L ⁴⁴ include the same groups as exemplified for A ^a41 .
Examples of the saturated hydrocarbon group for R ^f6 include the same groups as exemplified for R ^a42 .
The alkanediyl group having 1 to 6 carbon atoms in L ⁴⁴ is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.

Examples of the structural unit represented by formula (a4-2) include structural units represented by formulas (a4-1-1) to (a4-1-11), respectively. A structural unit in which the methyl group corresponding to R ^f5 in structural unit (a4-2) is replaced with a hydrogen atom is also included as a structural unit represented by 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。）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 divalent saturated hydrocarbon group having 1 to 18 carbon atoms 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 saturated hydrocarbon group having 1 to 17 carbon atoms 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 number of carbon atoms in 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 which may have a fluorine atom in A ^f13 is preferably a divalent aliphatic saturated hydrocarbon group which may have a fluorine atom and a divalent saturated hydrocarbon group which may have a fluorine atom. A divalent alicyclic saturated hydrocarbon group is preferable, and a perfluoroalkanediyl group is more preferable.
Examples of the divalent aliphatic hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; difluoromethylene group, perfluoroethylene group, perfluoroethylene group, etc. Examples include perfluoroalkanediyl groups such as a propanediyl group, a perfluorobutanediyl group, and a perfluoropentanediyl group.
The divalent alicyclic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic group include an adamantanediyl group, a norbornanediyl group, and a perfluoroadamantanediyl group.

Examples of the saturated hydrocarbon group of A ^f14 and the saturated hydrocarbon group which may have a fluorine atom 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 of 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group, perfluorooctyl group, etc. 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 , perfluoroadamantylmethyl group, etc. are preferred.

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 chain hydrocarbon group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and a chain type hydrocarbon group having 2 to 3 carbon atoms. Hydrocarbon groups are more preferred.
The saturated hydrocarbon group of A ^f14 is preferably a group containing a chain hydrocarbon group having 3 to 12 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and a chain hydrocarbon group having 3 to 10 carbon atoms. and a group containing an alicyclic hydrocarbon group having 3 to 10 carbon atoms is more preferred. Among these, A ^f14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group.

Examples of the structural unit represented by formula (a4-3) include structural units represented by formulas (a4-1'-1) to (a4-1'-11), respectively. A structural unit in which the methyl group corresponding to R ^f7 in structural unit (a4-3) is replaced with a hydrogen atom is also included as the structural unit represented by 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。］ The structural unit (a4) also includes a structural unit 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 saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom. ]

Examples of the saturated hydrocarbon group for R ^f22 include the same saturated hydrocarbon group as the saturated hydrocarbon group represented by R ^a42 . R ^f22 is preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom. Preferably, an alkyl group having 1 to 6 carbon atoms and having a fluorine atom is more preferable.

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

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

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

［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 the non-eliminating hydrocarbon group possessed by the structural unit (a5) include groups having a linear, branched or cyclic hydrocarbon group. Among these, the structural unit (a5) is preferably a group having an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include a structural unit represented by formula (a5-1).

[In formula (a5-1),
R ⁵¹ represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the 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 the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group.
Examples of aliphatic hydrocarbon groups having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, and - Alkyl groups such as ethylhexyl group.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group.
R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, norbornyl group or cyclohexyl group.

Examples of the divalent saturated hydrocarbon group in L ⁵⁵ include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and preferably a divalent chain saturated hydrocarbon group. .
Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group, and pentanediyl group.
The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include 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。 Examples of groups in which -CH ₂ - contained in the divalent saturated hydrocarbon group represented by L ⁵⁵ are replaced with -O- or -CO- include formulas (L1-1) to (L1-4). The groups represented can be mentioned. In the following formula, * 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 aliphatic saturated 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 represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent alicyclic saturated 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 divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, 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 divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, 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 aliphatic saturated 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 aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
W ^x1 is preferably a divalent alicyclic saturated 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 following divalent groups.

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).

Examples of the structural unit (a5-1) include the structural units shown below 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 a structural unit (a5), its content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and 3 to 30 mol%, based on the total structural units of the resin (A). More preferably 15 mol%.

<Structural unit (II)>
The resin (A) may further contain a structural unit (hereinafter sometimes referred to as "structural unit (II)") that decomposes when exposed to light and generates an acid. Specific examples include the structural units described in JP-A No. 2016-79235, which include structural units having a sulfonate group or carboxylate group and an organic cation in the side chain, or structural units having a sulfonio group and an organic anion in the side chain. It is preferable that

［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。］ The structural unit having a sulfonate group or carboxylate group and an organic cation in its side chain is preferably a structural unit represented by formula (II-2-A').

[In 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-. Often, the 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 contain a halogen atom, or a hydroxy group.
A ^X1 represents an alkanediyl group having 1 to 8 carbon atoms, and the 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. ]

Examples of the halogen atom represented by R ^III3 include fluorine atom, chlorine atom, bromine atom, and iodine atom.
The alkyl group having 1 to 6 carbon atoms and optionally having a halogen atom represented by R ^III3 includes the alkyl group having 1 to 6 carbon atoms optionally having a halogen atom represented by R ^a8 ; The same thing can be mentioned.
The alkanediyl group having 1 to 8 carbon atoms represented by ^A , 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. Can be mentioned.
Examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted with A ^x1 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert group. -butyl group, perfluoropentyl group, perfluorohexyl group, etc.

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. or a combination of these may 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 , linear alkanediyl groups such as dodecane-1,12-diyl group; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group , pentane-1,4-diyl group, branched alkanediyl group such as 2-methylbutane-1,4-diyl group; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1 ,4-diyl group, cycloalkanediyl group such as cyclooctane-1,5-diyl group; divalent monocyclic alicyclic saturated hydrocarbon group; norbornane-1,4-diyl group, norbornane-2, Examples include divalent polycyclic alicyclic saturated hydrocarbon groups such as 5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.

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). Can be mentioned. However, the number of carbon atoms in each of the saturated hydrocarbon groups before --CH ₂ -- is replaced with --O-, --S-, or --CO- is 17 or less. In the formula below, * and ** represent a binding site, and * represents a binding site with A ^x1 .

X ³ represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms.
X ⁴ represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
X ⁵ represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
X ⁶ represents 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.

Examples of the organic cation 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 of formulas (b2-1) to (b2-4) (hereinafter sometimes referred to as "cation (b2-1)" etc. depending on the formula number) is Can be mentioned.

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、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
ｍ２及びｎ２は、それぞれ独立に０～５のいずれかの整数を表す。
ｍ２が２以上のとき、複数のＲ^b7は同一でも異なってもよく、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、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
Ｌ^b31は、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。

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. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with 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. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may bond to each other and 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 represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent any integer from 0 to 5.
When m2 is 2 or more, multiple R ^b7s may be the same or different; when n2 is 2 or more, multiple R ^b8s 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 bond to each other and 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; The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. It may be 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 is -O-, -S - or -CO- may be substituted.
R ^b13 to R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represent any integer from 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 ^b13s are the same or different; when p2 is 2 or more, multiple R ^b14s are the same or different; when q2 is 2 or more, multiple R ^b15s are the same or different. , when r2 is 2 or more, multiple R ^b16s are the same or different; when s2 is 2 or more, multiple R ^b17s are the same or different; when t2 is 2 or more, multiple R ^b18s are the same or different; different.

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。 The aliphatic hydrocarbon group refers to a chain hydrocarbon group and an alicyclic hydrocarbon group.
Examples of 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. Can be mentioned.
In particular, the chain hydrocarbon groups R ^b9 to R ^b12 preferably have 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclo Examples include cycloalkyl groups such as heptyl group, cyclooctyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups.

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

Examples of 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-isopropyladamantane-2-yl group, methylnorbornyl group, isobornyl group, and the like. In an alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms in the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.

Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, biphenylyl group, naphthyl group, and phenanthryl group. 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 (tolyl group, xylyl group, cumenyl group, mesityl group) 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.).
In addition, when the aromatic hydrocarbon group includes 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 Groups are preferred.
Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include p-methoxyphenyl group.
Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, and naphthylethyl group.

Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, and dodecyloxy group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkylcarbonyloxy group include methylcarbonyloxy group, ethylcarbonyloxy group, propylcarbonyloxy group, isopropylcarbonyloxy group, butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, and pentylcarbonyloxy group. , hexylcarbonyloxy group, octylcarbonyloxy group, and 2-ethylhexylcarbonyloxy group.

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

The ring formed by R ^b9 and R ^b10 together may be monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. Examples of this ring include a 3- to 12-membered ring, preferably a 3- to 7-membered ring. Examples include thiolane-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 monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. Examples of this ring include a 3- to 12-membered ring, preferably a 3- to 7-membered ring. Examples include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Among cations (b2-1) to cations (b2-4), 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.

［式（ＩＩ－２－Ａ）中、Ｒ^III3、Ｘ^III3及びＺＡ^＋は、上記と同じ意味を表す。
ｚｘ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、ｚｘ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 formula (II-2-A), R ^III3 , X ^III3 and ZA ⁺ represent the same meanings as above.
zx 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 zx is 2 or more, a plurality of R ^III2 and R ^III4 may be the same or different. You can leave it there.
Q ^a and Q ^b each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. ]

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 group having 1 to 6 carbon atoms represented by Q ^b1 described below. .

［式（ＩＩ－２－Ａ－１）中、
Ｒ^III2、Ｒ^III3、Ｒ^III4、Ｑ^a、Ｑ^b、ｚｘ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 formula (II-2-A-1),
R ^III2 , R ^III3 , R ^III4 , Q ^a , Q ^b , zx and ZA ⁺ represent 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-. Often, the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with a halogen atom or a hydroxy group. ]

The saturated hydrocarbon group having 1 to 12 carbon atoms represented by R ^III5 includes methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Straight chain or branched alkyl groups such as heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group are mentioned.
Examples of the divalent saturated hydrocarbon group represented by X ^I2 include those similar to the divalent saturated hydrocarbon group 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。
ｍｘ及びｎｘは、それぞれ独立に、１又は２を表す。］ The structural unit represented by formula (II-2-A-1) is preferably a structural unit represented by formula (II-2-A-2).

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

Examples of the structural unit represented by formula (II-2-A') include the following structural units and the structural units described in International Publication No. 2012/050015. 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。具体的には、Ｒ^a1’、Ｒ^a2’及びＲ^a3’における炭化水素基と同じものが挙げられる。
Ｒ^II4で表されるハロゲン原子としては、フッ素原子、塩素原子、臭素原子及びヨウ素原子等が挙げられる。
Ｒ^II4で表されるハロゲン原子を有していてもよい炭素数１～６のアルキル基としては、Ｒ^a8で表されるハロゲン原子を有していてもよい炭素数１～６のアルキル基と同じものが挙げられる。
Ａ^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。 The structural unit having a sulfonio group and an organic anion in its side chain is preferably a structural unit represented by formula (II-1-1).

[In formula (II-1-1),
A ^II1 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 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.
Examples of the hydrocarbon group represented by R ^II2 and R ^II3 include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. Specifically, the same hydrocarbon groups as R ^a1' , R ^a2' and R ^a3' can be mentioned.
Examples of the halogen atom represented by R ^II4 include fluorine atom, chlorine atom, bromine atom, and iodine atom.
The alkyl group having 1 to 6 carbon atoms and optionally having a halogen atom represented by R ^II4 includes the alkyl group having 1 to 6 carbon atoms optionally having a halogen atom represented by R ^a8 ; The same things can be mentioned.
Examples of the divalent linking group represented by A ^II1 include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH ₂ - contained in the divalent saturated hydrocarbon group is It may be replaced with -O-, -S- or -CO-. Specifically, the same divalent saturated hydrocarbon group having 1 to 18 carbon atoms as represented by X ^III3 can be mentioned.

Examples of the cation-containing structural unit in formula (II-1-1) include the structural units shown below.

Examples of the organic anion represented by A ^- include sulfonic acid anions, sulfonylimide anions, sulfonylmethide anions, and carboxylic acid anions. The organic anion represented by A ^- is preferably a sulfonate anion, and the sulfonate anion is more preferably an anion contained in a salt represented by formula (B1) described below.

Examples of the sulfonylimide anion represented by A ^- include the following.

Examples of sulfonyl methide anions include the following.

Examples of carboxylic acid anions include the following.

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

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

The resin (A) may have structural units other than the above-mentioned structural units, and examples of such structural units include structural units well known in the art.

The resin (A) is preferably a resin consisting of a structural unit (a2-A) and a structural unit (a1), that is, a copolymer of a monomer (a2-A) and a monomer (a1), and a structural unit (a2-A). -A), a structural unit (a1), and a structural unit (s), that is, a copolymer of monomer (a2-A), monomer (a1), and monomer (s).
The structural unit (a1) preferably includes the structural unit (a1-0), the structural unit (a1-1), the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group), and the structural unit (a1-4), more preferably from the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group) At least one kind selected from the group consisting of, more preferably at least two kinds.
The structural unit (s) is preferably at least one type selected from the group consisting of the structural unit (a2) and the structural unit (a3). Structural unit (a2) is preferably structural unit (a2-1). 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). At least one type selected from

Each structural unit constituting 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, even more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, even more preferably 15,000 or less). In this specification, the weight average molecular weight is a value determined by gel permeation chromatography under the conditions described in Examples.

<Resin other than resin (A)>
The resist composition of the present invention may further contain a resin other than resin (A).
Examples of resins other than resin (A) include resins containing structural unit (a4) or structural unit (a5) (hereinafter sometimes referred to as resin (X)), and those represented by formula (a2-A). Examples include resins that do not contain structural units and contain structural units that have acid-labile groups (hereinafter sometimes referred to as resins (AY)).

Among the resins (X), resins containing the structural unit (a4) are preferred. That is, a resin containing a structural unit having a fluorine atom 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, based on the total of all structural units of the resin (X). , more preferably 45 mol% or more.
Structural units that resin (X) and resin (AY) may further include include structural units (a1), structural units (a2), structural units (a3), and structural units derived from other known monomers. can be mentioned. Among these, the resin (X) is preferably a resin consisting only of the structural unit (a4) and/or the structural unit (a5).

Each of the structural units constituting the resin (X) and the resin (AY) may be used alone or in combination of two or more. By using a monomer that induces these structural units, known polymerization methods (for example, radical polymerization method). The content of each structural unit in the resin (X) can be adjusted by adjusting the amount of monomer used for polymerization.
The weight average molecular weights of the resin (X) and the resin (AY) are each independently preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). be. The means for measuring the weight average molecular weight of resin (X) and resin (AY) is the same as in the case of resin (A).

When the resist composition of the present invention contains a resin (AY), its content is usually 1 to 2,500 parts by mass (more preferably 10 to 1,000 parts by mass) based on 100 parts by mass of the resin (A). be.
Further, when the resist composition contains resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, based on 100 parts by mass of resin (A). , more preferably 1 to 40 parts by weight, particularly preferably 1 to 30 parts by weight, particularly preferably 1 to 8 parts by weight.

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, based on the solid content of the resist composition. In addition, 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 based on the solid content of the resist composition. It is preferably at most 90% by mass and at most 99% by mass. The solid content of the resist composition and the resin content relative to the solid content can be measured by known analytical means such as liquid chromatography or gas chromatography.

<Salt represented by formula (I)>
The resist composition of the present invention contains a salt represented by formula (I) (hereinafter sometimes referred to as "salt I").
Of the salt (I), the side having a negative charge may be referred to as an "anion (I)", and the side having a positive charge may be referred to as a "cation (I)".

In formula (I), the perfluoroalkyl group for R ³ and R ⁴ includes a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group. , perfluoropentyl group, perfluorohexyl group, etc.
R ³ and R ⁴ are preferably hydrogen atoms.
It is preferable that z is 1 or 2.
X ¹ is *-CO-O-, *-O-CO- or *-O-CO-O- (* represents a bonding site with C(R ³ )(R ⁴ ) or CHCF ₃ ). It is preferably *-O-CO- (* represents a binding site with C(R ³ ) (R ⁴ ) or CHCF ₃ ).

Examples of the divalent saturated hydrocarbon group represented by L ¹ include alkanediyl groups, monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and two or more of these groups A divalent hydrocarbon group formed from a combination of an alicyclic hydrocarbon group and an alkanediyl group 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;
A monocyclic cycloalkanediyl group such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, or a 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 Examples include groups.
-CH ₂ - contained in the divalent saturated hydrocarbon group having 1 to 28 carbon atoms in L ¹ may be replaced with -O-, -S-, -SO ₂ - or -CO-.
When -CH ₂ - contained in the divalent saturated hydrocarbon group having 1 to 28 carbon atoms represented by L ¹ is replaced with -O-, -S-, -SO ₂ - or -CO-, the substitution Let the previous carbon number be the carbon number of the hydrocarbon group.
Examples of the group in which -CH ₂ - contained in the alkanediyl group of L ¹ is replaced with -O- or -CO- include a hydroxy group, an alkoxy group, an alkylcarbonyl group, an alkylcarbonyloxy group, a carboxy group, etc. Among them, a hydroxy group is preferred.
L ¹ is a single bond, an alkanediyl group (however, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-), or an alkanediyl group and an alicyclic saturated group. A group formed by combining a hydrocarbon group (However, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-, and a group formed by combining a hydrocarbon group contained in the alicyclic saturated hydrocarbon group) -CH ₂ - may be replaced with -O-, -S-, -SO ₂ - or -CO-), and is preferably a single bond, an alkanediyl group, or an alicyclic group with an alkanediyl group A group formed by combining a saturated hydrocarbon group (however, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-) is more preferable, and a single bond , an alkanediyl group or a group formed by combining an alkanediyl group and an adamantanediyl group (however, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-). It is even more preferable that there be.

多環式の脂環式炭化水素基としては、ノルボルニル基、アダマンチル基及び以下に示す基等が挙げられる。

Ｒ^５の脂環式炭化水素基が有してもよい置換基としては、ハロゲン原子、ヒドロキシ基、シアノ基、カルボキシ基、炭素数１～１２のアルキル基、炭素数１～１２のアルコキシ基及びこれらの基のうち２種以上を組み合わせた基が挙げられる。
ハロゲン原子としては、フッ素原子、塩素原子、臭素原子及びヨウ素原子等が挙げられる。
炭素数１～１２のアルキル基としては、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、オクチル基、ノニル基等が挙げられる。
炭素数１～１２のアルコキシ基としては、メトキシ基、エトキシ基、プロポキシ基、ブトキシ基、ペンチルオキシ基、ヘキシルオキシ基、オクチルオキシ基、２－エチルヘキシルオキシ基、ノニルオキシ基、デシルオキシ基、ウンデシルオキシ基、ドデシルオキシ基等が挙げられる。
２種以上を組み合わせた基としては、炭素数２～１３のアルコキシカルボニル基、炭素数２～１３のアルキルカルボニル基及び炭素数２～１３のアルキルカルボニルオキシ基等が挙げられる。
炭素数２～１３のアルコキシカルボニル基、炭素数２～１３のアルキルカルボニル基及び炭素数２～１３のアルキルカルボニルオキシ基等は、上述したアルキル基又はアルコキシ基にカルボニル基又はカルボニルオキシ基が結合した基を表す。
炭素数２～１３のアルコキシカルボニル基としては、メトキシカルボニル基、エトキシカルボニル基、ブトキシカルボニル基等が挙げられ、炭素数２～１３のアルキルカルボニル基としては、アセチル基、プロピオニル基及びブチリル基等が挙げられ、炭素数２～１３のアルキルカルボニルオキシ基としては、アセチルオキシ基、プロピオニルオキシ基、ブチリルオキシ基等が挙げられる。
Ｒ^５で表される炭素数３～１８の脂環式炭化水素基は、１つの置換基又は同一の又は異なる複数の置換基を有していてもよい。
Ｒ^５の炭素数３～１８の脂環式炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－ＳＯ_２－に置き換わっていてもよい。
Ｒ^５で表される炭素数３～１８の脂環式炭化水素基が置換基を有する場合又は該脂環式炭化水素基に含まれる－ＣＨ_２－が－Ｏ－、－Ｓ－、－ＣＯ－又は－ＳＯ_２－に置き換わっている場合、置き換わる前の炭素数を該炭化水素基の炭素数とする。
Ｒ^５の脂環式炭化水素基に含まれる－ＣＨ₂－が－Ｏ－、－Ｓ－、－ＣＯ－又は－ＳＯ_２－に置き換わった基としては以下のものが挙げられる。

なかでも、以下のものが好ましい。

Examples of the alicyclic hydrocarbon group having 3 to 18 carbon atoms for R ⁵ include monocyclic or polycyclic alicyclic hydrocarbon groups.
Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups shown below, such as a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

Examples of the polycyclic alicyclic hydrocarbon group include a norbornyl group, an adamantyl group, and the groups shown below.

Examples of substituents that the alicyclic hydrocarbon group of R ⁵ may have include a halogen atom, a hydroxy group, a cyano group, a carboxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and Examples include a combination of two or more of these groups.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group 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, nonyl group, and the like.
Examples of the alkoxy group having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group group, dodecyloxy group, etc.
Examples of the group combining two or more types include an alkoxycarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyl group having 2 to 13 carbon atoms, and an alkylcarbonyloxy group having 2 to 13 carbon atoms.
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, etc. are those in which a carbonyl group or carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. represents a group.
Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group, and examples of the alkylcarbonyl group having 2 to 13 carbon atoms include acetyl group, propionyl group, butyryl group, etc. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, a butyryloxy group, and the like.
The alicyclic hydrocarbon group having 3 to 18 carbon atoms represented by R ⁵ may have one substituent or a plurality of the same or different substituents.
-CH ₂ - contained in the alicyclic hydrocarbon group having 3 to 18 carbon atoms in R ⁵ may be replaced with -O-, -S-, -CO- or -SO ₂ -.
When the alicyclic hydrocarbon group having 3 to 18 carbon atoms represented by R ⁵ has a substituent, or -CH ₂ - contained in the alicyclic hydrocarbon group is -O-, -S-, -CO - or -SO ₂ -, the number of carbon atoms before substitution is the number of carbon atoms of the hydrocarbon group.
Groups in which -CH ₂ - contained in the alicyclic hydrocarbon group of R ⁵ is replaced with -O-, -S-, -CO- or -SO ₂ - include the following.

Among these, the following are preferred.

The divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms represented by R ⁵ is a polycyclic alicyclic hydrocarbon group such as a norbornyl group or an adamantyl group (included in the alicyclic hydrocarbon group). -CH ₂ - may be replaced with -O-, -S-, -CO- or -SO ₂ -), and is preferably an adamantyl group or a norbornyl group.
R ⁵ is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (-CH ₂ - contained in the alicyclic hydrocarbon group is replaced by -O- or -CO-). ) is preferable,
An alicyclic hydrocarbon group having 3 to 10 carbon atoms that may have one or more substituents selected from the group consisting of a halogen atom and a hydroxy group (-CH ₂ - contained in the alicyclic hydrocarbon group) may be replaced with -O- or -CO-) is more preferable,
A polycyclic alicyclic hydrocarbon group having 7 to 10 carbon atoms that may have one or more substituents selected from the group consisting of a halogen atom and a hydroxy group (included in the alicyclic hydrocarbon group) -CH ₂ - may be replaced with -O- or -CO-) is more preferable,
An adamantyl group that may have one or more substituents selected from the group consisting of a halogen atom and a hydroxyl group (-CH ₂ - contained in the adamantyl group may be replaced with -CO-). Even more preferably,
Further, R ⁵ represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms having a hydroxyl group, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (the alicyclic It is more preferable that at least one of -CH ₂ - contained in the cyclic hydrocarbon group is replaced with -O-, -S-, -SO ₂ - or -CO-.

［式（Ｉａ）中、
Ｒ^３及びＲ^４は、それぞれ独立に、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す。
ｚは、０～６のいずれかの整数を表し、ｚが２以上のとき、複数のＲ^３及びＲ^４は互いに同一であっても異なってもよい。
Ｘ¹は、＊－ＣＯ－Ｏ－、＊－Ｏ－ＣＯ－、＊－Ｏ－ＣＯ－Ｏ－又は＊－Ｏ－（＊はＣ（Ｒ^３）（Ｒ^４）又はＣＨＣＦ_３との結合部位を表す。）を表す。
Ｌ¹は、単結合又は炭素数１～２８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－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ｒ^5aは、水酸基を有する炭素数３～１８の脂環式炭化水素基を表すか、又は、置換基を有してもよい炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ_２－の少なくとも一つは、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わる。
Ｚ⁺は有機カチオンを表す。］
式（Ｉａ）中の全ての符号は、それぞれ前記と同じ意味を表す。 As the salt represented by formula (I), a salt represented by formula (Ia) is preferable.

[In formula (Ia),
R ³ and R ⁴ each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents any integer from 0 to 6, and when z is 2 or more, the plurality of R ³ and R ⁴ may be the same or different.
X ¹ is *-CO-O-, *-O-CO-, *-O-CO-O- or *-O- (* is a bonding site with C(R ³ )(R ⁴ ) or CHCF ₃ ).
L ¹ represents a single bond or a divalent saturated hydrocarbon group having 1 to 28 carbon atoms, and -CH ₂ - contained in the saturated hydrocarbon group is -O-, -S-, -SO ₂ - or -CO- may be substituted.
R ^5a represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms having a hydroxyl group, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent; At least one of -CH ₂ - contained in the cyclic hydrocarbon group is replaced with -O-, -S-, -SO ₂ - or -CO-.
Z ⁺ represents an organic cation. ]
All the symbols in formula (Ia) represent the same meanings as above.

Examples of the anion (I) include the following anions. Among them, anions represented by formula (Ia-1) to formula (Ia-6), formula (Ia-13), formula (Ia-14), formula (Ia-17) to formula (Ia-18) is preferred.

Examples of the organic cation of Z ⁺ include the same ones as ZA ⁺ in the structural unit represented by formula (II-2-A'), and specifically, organic onium cations, organic sulfonium cations, organic iodonium cations, Examples include 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. Examples of the organic sulfonium cation and organic iodonium cation include cations represented by any of the above formulas (b2-1) to (b2-4).

Examples of the salt (I) include the salts listed in Table 1. For example, in Table 1, salt (I-1) is a salt consisting of an anion represented by formula (Ia-1) and a cation represented by formula (b2-c-1), and represents the salt shown below. .

Among them, salt (I) includes salt (I-1) to salt (I-6), salt (I-13), salt (I-14), and salt (I-19) to salt (I-24). , salt (I-31), salt (I-32), salt (I-37) ~ salt (I-42), salt (I-49), salt (I-50), salt (I-55) ~ Salt (I-60), Salt (I-67), Salt (I-68), Salt (I-73) to Salt (I-78), Salt (I-85), Salt (I-86), Salt (I-91) ~ Salt (I-96), Salt (I-103), Salt (I-104), Salt (I-109) ~ Salt (I-114), Salt (I-121), Salt ( I-122), salt (I-127) to salt (I-132), salt (I-139), salt (I-140), salt (I-145) to salt (I-150), salt (I -157), salt (I-158), salt (I-163) to salt (I-168), salt (I-175), and salt (I-176) are preferred.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における溶媒としては、クロロホルム、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 <Method for producing salt represented by formula (Ia)>
Among the salts represented by formula (Ia) (hereinafter sometimes referred to as salts (Ia)), the salts in which X ¹ is *-CO-O- (salts represented by formula (I1)) are, for example, , can be produced by reacting a salt represented by formula (I1-a) with carbonyldiimidazole in a solvent, and then reacting the salt represented by formula (I1-b) with a compound represented by formula (I1-b). .

(In the formula, all symbols represent the same meanings as above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 to 24 hours.

式（Ｉ１－ｂ）で表される化合物としては、下記式で表される化合物等が挙げられ、市場より容易に入手することができる。

Examples of the salt represented by formula (I1-a) include salts represented by the following, and can be produced with reference to the method described in JP-A No. 2008-127367.

Examples of the compound represented by formula (I1-b) include compounds represented by the following formula, etc., which can be easily obtained from the market.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における溶媒としては、クロロホルム、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。
式（Ｉ２－ａ）で表される塩は、例えば、以下で表される塩などが挙げられ、ＷＯ２０１１／０９３２８０号パンフレットに記載された方法を参考にして製造することができる。

式（Ｉ２－ｂ）で表される化合物としては、下記式で表される化合物等が挙げられ、市場より容易に入手することができる。

In salt (Ia), X ¹ is *-O-CO- (salt represented by formula (I2)), for example, a compound represented by formula (I2-b) in a solvent. , carbonyldiimidazole, and then further reacted with a salt represented by formula (I2-a).

(In the formula, all symbols represent the same meanings as above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 to 24 hours.
Examples of the salt represented by formula (I2-a) include salts represented by the following, and can be produced with reference to the method described in WO2011/093280 pamphlet.

Examples of the compound represented by formula (I2-b) include compounds represented by the following formula, etc., which can be easily obtained from the market.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における溶媒としては、クロロホルム、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 In salt (Ia), X ¹ is *-O-CO-O- (salt represented by formula (I3)), for example, a salt represented by formula (I2-a) and carbonyl di It can be produced by reacting with imidazole in a solvent and then further reacting with a compound represented by formula (I1-b).
Further, the salt represented by the formula (I3) can be prepared by, for example, reacting the compound represented by the formula (I1-b) with carbonyldiimidazole in a solvent, and then further forming the salt represented by the formula (I2-a). It can also be produced by reacting with the salts shown.

(In the formula, all symbols represent the same meanings as above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 to 24 hours.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における塩基としては、水酸化カリウム等が挙げられる。
この反応における溶媒としては、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 Salt (Ia) in which X ¹ is -O- (salt represented by formula (I4)) is a salt represented by formula (I2-a) and salt represented by formula (I1-b). It can be obtained by reacting the compound in a solvent in the presence of a base.

(In the formula, all symbols represent the same meanings as above.)
Examples of the base in this reaction include potassium hydroxide.
Examples of the solvent in this reaction include acetonitrile.
The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 to 24 hours.

The resist composition of the present invention may contain, in addition to the salt (I), an acid generator known in the resist field (hereinafter sometimes referred to as "acid generator (B)"). The acid generator (B) may be used alone or in combination of two or more.

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

As the acid generator (B), 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, U.S. Patent No. 3,779,778, U.S. Patent No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. It is possible to use compounds that generate acids upon radiation as described in . 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 types.

［式（Ｂ１）中、
Ｑ^b1及びＱ^b2は、それぞれ独立に、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１～２４の２価の飽和炭化水素基を表し、該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３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ（Ｏ）_２－又は－ＣＯ－に置き換わっていてもよい。
ＺＢ^＋は、有機カチオンを表す。］ The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)").

[In formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom 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-. , the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group that may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms that may have a substituent, and is included in the alicyclic hydrocarbon group. CH ₂ - may be replaced by -O-, -S(O) ₂ - or -CO-.
ZB ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group represented by Q ^b1 and Q ^b2 and the divalent saturated hydrocarbon group represented by L ^b1 are the same as R ³ , R ⁴ and L ¹ of formula (I).

Examples of groups in which -CH ₂ - contained in the divalent saturated hydrocarbon group represented by L ^b1 are replaced with -O- or -CO- include formulas (b1-1) to (b1-3) Examples include groups represented by any of the following. 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 a binding site; * represents a 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。
＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。］

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

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-, the carbon before being replaced The number is the number of carbon atoms in the saturated hydrocarbon group.
Examples of the divalent saturated hydrocarbon group include those similar to the divalent saturated hydrocarbon group of L ^b1 .
L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the 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, and the 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。］ 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). Preferred groups are
Examples of the group represented by formula (b1-1) include groups represented by formulas (b1-4) to (b1-8), respectively.

[In formula (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the 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 the 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 the 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 the 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 the 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 divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
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 divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

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), respectively.

In formula (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the 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, and the 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 the 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 the 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 the 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 the 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 the 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 the 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 the 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, the substituted Let the previous carbon number be the carbon number of the saturated hydrocarbon group.

Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, and an adamantylcarbonyloxy group.

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.

Examples of the alicyclic hydrocarbon group represented by Y 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(O) ₂ - or -CO-, the number may be one or two or more. good. Examples of such groups include groups represented by formulas (Y12) to (Y35) and formulas (Y39) to (Y41).

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（Ｙ４１）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）又は式（Ｙ４０）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）又は式（Ｙ４０）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）等の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 represented by Y preferably includes formulas (Y1) to (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), and formula (Y39). A group represented by any one of ~Formula (Y41), more preferably Formula (Y11), Formula (Y15), Formula (Y16), Formula (Y20), Formula (Y26), Formula (Y27), Formula (Y30), formula (Y31), formula (Y39), or formula (Y40), more preferably formula (Y11), formula (Y15), formula (Y20), formula (Y26), or formula (Y27), formula (Y30), formula (Y31), formula (Y39) or formula (Y40).
When the alicyclic hydrocarbon group represented by Y is a spiro ring such as formula (Y28) to formula (Y35) or formula (Y39) to formula (Y40), an alkanediyl group between two oxygen atoms preferably has one or more fluorine atoms. Moreover, among the alkanediyl groups included in the ketal structure, it is preferable that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

Substituents for 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 an alkyl group having 1 to 16 carbon atoms, an alkyl group having 3 to 16 carbon atoms, Represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these.ja represents any integer of 0 to 4.Alkyl group having 1 to 16 carbon atoms, and -CH ₂ - contained in the alicyclic hydrocarbon group having 3 to 16 carbon atoms may be replaced with -O-, -S(O) ₂ - or -CO-).
Substituents for the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms which may be substituted with a hydroxy group, and an alicyclic group having 3 to 16 carbon atoms. Hydrocarbon group, alkoxy group having 1 to 12 carbon atoms, aromatic hydrocarbon group having 6 to 18 carbon atoms, aralkyl group having 7 to 21 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, glycidyloxy group, -( CH ₂ ) _ja -CO-O-R ^b1 group or -(CH ₂ ) _ja -O-CO-R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alkyl group having 3 to 16 carbon atoms, Represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these.ja represents any integer of 0 to 4.Alkyl group having 1 to 16 carbon atoms, and -CH ₂ - contained in the alicyclic hydrocarbon group having 3 to 16 carbon atoms may be replaced with -O-, -S(O) ₂ - or -CO-).

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, and an adamantyl group.
Examples of aromatic hydrocarbon groups include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group, mesityl group. , biphenyl group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl group, and the like.
Examples of the alkyl group 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. group, decyl group, undecyl group, dodecyl group, etc.
Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, and dodecyloxy group.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.

Examples of Y include the following.

Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, more preferably an adamantyl group which may have a substituent; -CH ₂ - constituting the hydrogen group or adamantyl group may be replaced with -CO-, -S(O) ₂ - or -CO-. Y is more preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, or a group represented below.

As the sulfonic acid anion in the salt represented by formula (B1), anions represented by formulas (B1-A-1) to (B1-A-55) [hereinafter, "anion (B1 -A-1)” etc. ] is preferred, and formulas (B1-A-1) to (B1-A-4), formula (B1-A-9), formula (B1-A-10), and formulas (B1-A-24) to (B1-A-24) are preferred. (B1-A-33), Formula (B1-A-36) to Formula (B1-A-40), Formula (B1-A-47) to Formula (B1-A-55) Anions are more preferred.

ここでＲⁱ²～Ｒⁱ⁷は、それぞれ独立に、例えば、炭素数１～４のアルキル基、好ましくはメチル基又はエチル基である。Ｒⁱ⁸は、例えば、炭素数１～１２の鎖式炭化水素基、好ましくは炭素数１～４のアルキル基、炭素数５～１２の脂環式炭化水素基又はこれらを組合せることにより形成される基、より好ましくはメチル基、エチル基、シクロヘキシル基又はアダマンチル基である。Ｌ^A41は、単結合又は炭素数１～４のアルカンジイル基である。Ｑ^b1及びＱ^b2は、上記と同じ意味を表す。
式（Ｂ１）で表される塩におけるアニオンとしては、具体的には、特開２０１０－２０４６４６号公報に記載されたアニオンが挙げられる。

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 formed, for example, by 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. and more preferably a methyl group, ethyl group, cyclohexyl group or adamantyl group. L ^A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q ^b1 and Q ^b2 represent the same meanings as above.
Specific examples of the anion in the salt represented by formula (B1) include the anions described in JP-A No. 2010-204646.

Preferred examples of the sulfonic acid anion in the salt represented by formula (B1) include anions represented by formulas (B1a-1) to (B1a-34), respectively.

Among them, formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-16), formula (B1a-18), formula (B1a-19), formula (B1a-22 ) to (B1a-34) are preferred.

Examples of the organic cation of ZB ⁺ include the same ones as ZA ⁺ in the structural unit represented by formula (II-2-A').

The acid generator (B) is a combination of the above-mentioned sulfonic acid anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the acid generator (B), preferably formulas (B1a-1) to (B1a-3), formulas (B1a-7) to (B1a-16), formula (B1a-18), and formula (B1a- 19), a combination of an anion represented by any one of formulas (B1a-22) to (B1a-34) and a cation (b2-1) or a cation (b2-3).

Preferably, the acid generator (B) includes those represented by formulas (B1-1) to (B1-48), among which those containing an arylsulfonium cation are preferred, and those containing formula (B1-1) ~ Formula (B1-3), Formula (B1-5) ~ Formula (B1-7), Formula (B1-11) ~ Formula (B1-14), Formula (B1-20) ~ Formula (B1-26), Particularly preferred are those represented by formula (B1-29) and formula (B1-31) to formula (B1-48).

When containing salt (I) and acid generator (B) as acid generators, the content ratio of salt (I) and acid generator (B) (mass ratio; salt (I): acid generator ( B)) is usually 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, even more preferably 10:90 to 90. :10, particularly preferably 15:85 to 85:15.

<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, and 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, ethyl pyruvate, etc. Ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; Cyclic esters such as γ-butyrolactone; and the like. One type of solvent (E) may be used alone, or two or more types may be used.

<Quencher (C)>
Examples of the quencher (C) include salts that generate an acid that is weaker in acidity than the acid generated from the basic nitrogen-containing organic compound and the acid generator (B). The content of the quencher (C) is preferably about 0.01 to 5% by mass, more preferably 0.01 to 3% by mass, based on the solid content of the resist composition.
Basic nitrogen-containing organic compounds include amines and ammonium salts. Amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.

Examples of 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, 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, etc. Diisopropylaniline is preferred, and 2,6-diisopropylaniline is more preferred.
Examples of ammonium salts include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethyl Examples include ammonium hydroxide, tetra-n-butylammonium salicylate, and choline.

The acidity of a salt that generates an acid with weaker acidity than the acid generated from the acid generator (B) is indicated by the acid dissociation constant (pKa). The salt that generates an acid with weaker acidity than the acid generated from the acid generator (B) is a salt in which the acid dissociation constant of the acid generated from the salt is usually -3<pKa, preferably -1<pKa. A salt with a pKa<7, more preferably a salt with a pKa<5.
Examples of the salt that generates an acid with a weaker acidity than the acid generated from the acid generator (B) include a salt represented by the following formula, a salt represented by the formula (D) described in JP-A-2015-147926; (hereinafter sometimes referred to as "weak acid inner salt (D)"), as well as JP 2012-229206, JP 2012-6908, JP 2012-72109, and JP 2011-39502. Examples include salts described in Japanese Patent Publication No. 2011-191745. Preferably, it is a weak acid inner salt (D).

Examples of the weak acid inner salt (D) include the following salts.

<Other ingredients>
The resist composition of the present invention may contain components other than the above-mentioned components (hereinafter sometimes referred to as "other components (F)"), if necessary. Other components (F) are not particularly limited, and additives known in the resist field, 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 salt (I), a resin (A), an acid generator (B), and, if necessary, a resin other than the resin (A) used, a solvent (E), a quencher ( It can be prepared by mixing C) and other components (F). The mixing order is arbitrary and is not particularly limited. An appropriate temperature for mixing can be 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 it using a filter with a pore size of about 0.003 to 0.2 μm.

<Resist pattern manufacturing method>
The method for manufacturing a resist pattern of the present invention includes:
(1) Applying the resist composition of the present invention onto a substrate,
(2) drying the applied composition to form a composition layer;
(3) exposing the composition layer to light;
(4) a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.
The resist composition can be applied onto the substrate using a commonly used device such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers. Before applying the resist composition, the substrate may be cleaned, or an antireflection film or the like may be formed on the substrate.
By drying the applied composition, the solvent is removed and a composition layer is formed. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or by using a pressure reduction device. The heating temperature is preferably 50 to 200°C, and the heating time is preferably 10 to 180 seconds. Further, the pressure during reduced pressure drying is preferably about 1 to 1.0×10 ⁵ Pa.
The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid state laser light source (YAG or semiconductor laser). etc.) that converts the wavelength of laser light and emits harmonic laser light in the far ultraviolet or vacuum ultraviolet range, and uses various methods such as those that emit electron beams and ultraviolet light (EUV). Can be done. Note that in this specification, irradiation with these radiations may be collectively referred to as "exposure." During exposure, the 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 writing 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 in acid-labile groups. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C.
The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dip method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably, for example, 5 to 60°C, and the development time is, for example, preferably 5 to 300 seconds. By selecting the type of developer as described below, a positive resist pattern or a negative resist pattern can be manufactured.
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 the various alkaline aqueous solutions used in this field. Examples include aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline). The alkaline developer may contain a surfactant.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove water remaining on the substrate and pattern.
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 organic developers 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. Examples include ether solvents; amide solvents such as N,N-dimethylacetamide; and 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 even more preferably substantially only the organic solvent.
Among these, as the organic developer, a developer containing butyl acetate and/or 2-heptanone is preferred. 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. Further, the organic developer may contain a trace amount of water.
During development, development may be stopped by replacing the organic developer with a different type of solvent.
It is preferable to wash the resist pattern after development with a rinsing liquid. The rinsing liquid is not particularly limited as long as it does not dissolve the resist pattern, and solutions containing common organic solvents can be used, and alcohol solvents or ester solvents are preferable.
After cleaning, it is preferable to remove the rinsing 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 for electron beam (EB) exposure. It is suitable as a resist composition for line (EB) exposure or a resist composition for EUV exposure, and is useful for microfabrication of semiconductors.

The present invention will be described in more detail with reference to Examples. In the examples, "%" and "part" expressing content or amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
Column: TSKgel Multipore HXL-M x 3+guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0mL/min
Detector: RI detector Column temperature: 40℃
Injection volume: 100μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)
The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Model 1100 manufactured by Agilent; MASS: Model LC/MSD manufactured by Agilent). 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１．８０部及びクロロホルム２０部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－１－ｂ）で表される化合物１．７０部を添加し、さらに、５０℃で２時間攪拌した。得られた混合物に、式（Ｉ－１－ｃ）で表される塩４．７０部を添加し、さらに、５０℃で２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１０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１０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、濃縮残渣に、アセトニトリル１部及びｔｅｒｔ－ブチルメチルエーテル１９部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ－１）で表される塩４．４２部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３６９．１ Synthesis Example 1: Synthesis of salt represented by formula (I-1)

1.80 parts of the compound represented by formula (I-1-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.70 parts of the compound represented by formula (I-1-b) was added to the resulting mixture, and the mixture was further stirred at 50°C for 2 hours. 4.70 parts of a salt represented by formula (I-1-c) was added to the resulting mixture, which was further stirred at 50°C for 2 hours and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% oxalic acid aqueous solution was added and stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the layers were separated and the organic layer was taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, 1 part of acetonitrile and 19 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 4.42 parts of the salt represented by I-1) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI(-)Spectrum): M ^- 369.1

式（Ｉ－２－ａ）で表される化合物１．９６部及びクロロホルム２０部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－１－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。得られた混合物に、式（Ｉ－１－ｃ）で表される塩４．７０部を添加し、さらに、５０℃で２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１０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１０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、濃縮残渣に、アセトニトリル１部及びｔｅｒｔ－ブチルメチルエーテル１９部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ－２）で表される塩４．１２部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３８５．１ Example 1: Synthesis of salt represented by formula (I-2)

1.96 parts of the compound represented by formula (I-2-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.62 parts of the compound represented by formula (I-1-b) was added to the resulting mixture, and the mixture was further stirred at 50° C. for 2 hours. 4.70 parts of a salt represented by formula (I-1-c) was added to the resulting mixture, which was further stirred at 50°C for 2 hours and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% oxalic acid aqueous solution was added and stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the layers were separated and the organic layer was taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, 1 part of acetonitrile and 19 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 4.12 parts of the salt represented by I-2) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI(-)Spectrum): M ^- 385.1

式（Ｉ－３－ａ）で表される化合物１．９４部及びクロロホルム２０部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－１－ｂ）で表される化合物１．７０部を添加し、さらに、５０℃で２時間攪拌した。得られた混合物に、式（Ｉ－１－ｃ）で表される塩４．７０部を添加し、さらに、５０℃で２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１０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１０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、濃縮残渣に、アセトニトリル１部及びｔｅｒｔ－ブチルメチルエーテル１９部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ－３）で表される塩４．５８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３８３．１ Example 2: Synthesis of salt represented by formula (I-3)

1.94 parts of the compound represented by formula (I-3-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.70 parts of the compound represented by formula (I-1-b) was added to the resulting mixture, and the mixture was further stirred at 50°C for 2 hours. 4.70 parts of a salt represented by formula (I-1-c) was added to the resulting mixture, which was further stirred at 50°C for 2 hours and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% oxalic acid aqueous solution was added and stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the layers were separated and the organic layer was taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, 1 part of acetonitrile and 19 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 4.58 parts of the salt represented by I-3) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI(-)Spectrum): M ^- 383.1

式（Ｉ－１３－ａ）で表される化合物３．３８部及びクロロホルム２０部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－１－ｂ）で表される化合物１．７０部を添加し、さらに、５０℃で２時間攪拌した。得られた混合物に、式（Ｉ－１－ｃ）で表される塩４．７０部を添加し、さらに、５０℃で２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１０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１０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、濃縮残渣に、アセトニトリル１部及びｔｅｒｔ－ブチルメチルエーテル１９部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ－１３）で表される塩４．３９部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５２７．１ Example 3: Synthesis of salt represented by formula (I-13)

3.38 parts of the compound represented by formula (I-13-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.70 parts of the compound represented by formula (I-1-b) was added to the resulting mixture, and the mixture was further stirred at 50°C for 2 hours. 4.70 parts of a salt represented by formula (I-1-c) was added to the resulting mixture, which was further stirred at 50°C for 2 hours and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% oxalic acid aqueous solution was added and stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated five times. The obtained organic layer was concentrated, 1 part of acetonitrile and 19 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 4.39 parts of a salt represented by I-13) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI(-)Spectrum): M ^- 527.1

式（Ｉ－１－ａ）で表される化合物１．８０部及びクロロホルム２０部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－１－ｂ）で表される化合物１．７０部を添加し、さらに、５０℃で２時間攪拌した。得られた混合物に、式（Ｉ－４－ｃ）で表される塩４．５６部を添加し、さらに、５０℃で２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１０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１０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、濃縮残渣に、アセトニトリル１部及びｔｅｒｔ－ブチルメチルエーテル１９部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ－４）で表される塩４．２８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３５５．１ Synthesis Example 2: Synthesis of salt represented by formula (I-4)

1.80 parts of the compound represented by formula (I-1-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.70 parts of the compound represented by formula (I-1-b) was added to the resulting mixture, and the mixture was further stirred at 50°C for 2 hours. 4.56 parts of a salt represented by formula (I-4-c) was added to the resulting mixture, which was further stirred at 50°C for 2 hours and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% oxalic acid aqueous solution was added and stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the layers were separated and the organic layer was taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, 1 part of acetonitrile and 19 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 4.28 parts of the salt represented by I-4) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI(-)Spectrum): M ^- 355.1

式（Ｉ－２－ａ）で表される化合物１．９６部及びクロロホルム２０部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－１－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。得られた混合物に、式（Ｉ－９２－ｃ）で表される塩４．８９部を添加し、さらに、５０℃で２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１０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１０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、濃縮残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ－９２）で表される塩３．３６部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２８１．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３８５．１ Example 4: Synthesis of salt represented by formula (I-92)

1.96 parts of the compound represented by formula (I-2-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.62 parts of the compound represented by formula (I-1-b) was added to the resulting mixture, and the mixture was further stirred at 50°C for 2 hours. 4.89 parts of a salt represented by formula (I-92-c) was added to the resulting mixture, which was further stirred at 50°C for 2 hours and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% oxalic acid aqueous solution was added and stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated five times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula (I-92). 3.36 parts of the salt represented by was obtained.
MASS (ESI (+) Spectrum): M ⁺ 281.1
MASS (ESI(-)Spectrum): M ^- 385.1

式（Ｉ－３－ａ）で表される化合物１．９４部及びクロロホルム２０部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－１－ｂ）で表される化合物１．７０部を添加し、さらに、５０℃で２時間攪拌した。得られた混合物に、式（Ｉ－９２－ｃ）で表される塩４．８９部を添加し、さらに、５０℃で２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１０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１０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、濃縮残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ－９３）で表される塩３．６６部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２８１．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３８３．１ Example 5: Synthesis of salt represented by formula (I-93)

1.94 parts of the compound represented by formula (I-3-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.70 parts of the compound represented by formula (I-1-b) was added to the resulting mixture, and the mixture was further stirred at 50°C for 2 hours. To the resulting mixture, 4.89 parts of a salt represented by formula (I-92-c) was added, and the mixture was further stirred at 50°C for 2 hours, and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% oxalic acid aqueous solution was added and stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the layers were separated and the organic layer was taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula (I-93). 3.66 parts of the salt represented by was obtained.
MASS (ESI (+) Spectrum): M ⁺ 281.1
MASS (ESI(-)Spectrum): M ^- 383.1

式（Ｉ－１３－ａ）で表される化合物３．３８部及びクロロホルム２０部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－１－ｂ）で表される化合物１．７０部を添加し、さらに、５０℃で２時間攪拌した。得られた混合物に、式（Ｉ－９２－ｃ）で表される塩４．８９部を添加し、さらに、５０℃で２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１０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１０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、濃縮残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ－１０３）で表される塩２．９１部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２８１．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５２７．１ Example 6: Synthesis of salt represented by formula (I-103)

3.38 parts of the compound represented by formula (I-13-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.70 parts of the compound represented by formula (I-1-b) was added to the resulting mixture, and the mixture was further stirred at 50°C for 2 hours. To the resulting mixture, 4.89 parts of a salt represented by formula (I-92-c) was added, and the mixture was further stirred at 50°C for 2 hours, and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% oxalic acid aqueous solution was added and stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the layers were separated and the organic layer was taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula (I-103). 2.91 parts of the salt represented by was obtained.
MASS (ESI (+) Spectrum): M ⁺ 281.1
MASS (ESI(-)Spectrum): M ^- 527.1

式（Ｉ－２－ａ）で表される化合物１．９６部及びクロロホルム２０部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－１－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。得られた混合物に、式（Ｉ－１１０－ｃ）で表される塩５．２４部を添加し、さらに、５０℃で２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１０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１０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、濃縮残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ－１１０）で表される塩２．９５部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３１７．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３８５．１ Example 7: Synthesis of salt represented by formula (I-110)

1.96 parts of the compound represented by formula (I-2-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.62 parts of the compound represented by formula (I-1-b) was added to the resulting mixture, and the mixture was further stirred at 50°C for 2 hours. To the obtained mixture, 5.24 parts of a salt represented by formula (I-110-c) was added, and the mixture was further stirred at 50°C for 2 hours, and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% oxalic acid aqueous solution was added and stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated five times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant was removed and concentrated to obtain the formula (I-110). 2.95 parts of the salt represented by was obtained.
MASS (ESI (+) Spectrum): M ⁺ 317.1
MASS (ESI(-)Spectrum): M ^- 385.1

式（Ｉ－３－ａ）で表される化合物１．９４部及びクロロホルム２０部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－１－ｂ）で表される化合物１．７０部を添加し、さらに、５０℃で２時間攪拌した。得られた混合物に、式（Ｉ－１１０－ｃ）で表される塩５．２４部を添加し、さらに、５０℃で２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１０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１０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、濃縮残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ－１１１）で表される塩３．１２部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３１７．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３８３．１ Example 8: Synthesis of salt represented by formula (I-111)

1.94 parts of the compound represented by formula (I-3-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.70 parts of the compound represented by formula (I-1-b) was added to the resulting mixture, and the mixture was further stirred at 50°C for 2 hours. To the resulting mixture, 5.24 parts of a salt represented by formula (I-110-c) was added, and the mixture was further stirred at 50°C for 2 hours, and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% oxalic acid aqueous solution was added and stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the layers were separated and the organic layer was taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula (I-111). 3.12 parts of the salt represented by was obtained.
MASS (ESI (+) Spectrum): M ⁺ 317.1
MASS (ESI(-)Spectrum): M ^- 383.1

式（Ｉ－１３－ａ）で表される化合物３．３８部及びクロロホルム２０部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ－１－ｂ）で表される化合物１．７０部を添加し、さらに、５０℃で２時間攪拌した。得られた混合物に、式（Ｉ－１１０－ｃ）で表される塩５．２４部を添加し、さらに、５０℃で２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１０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１０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、濃縮残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ－１２１）で表される塩２．５６部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３１７．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５２７．１ Example 9: Synthesis of salt represented by formula (I-121)

3.38 parts of the compound represented by formula (I-13-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.70 parts of the compound represented by formula (I-1-b) was added to the resulting mixture, and the mixture was further stirred at 50°C for 2 hours. To the resulting mixture, 5.24 parts of a salt represented by formula (I-110-c) was added, and the mixture was further stirred at 50°C for 2 hours, and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% oxalic acid aqueous solution was added and stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the layers were separated and the organic layer was taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula (I-121). 2.56 parts of the salt represented by was obtained.
MASS (ESI (+) Spectrum): M ⁺ 317.1
MASS (ESI(-)Spectrum): M ^- 527.1

以下、これらのモノマーを式番号に応じて「モノマー（ａ１－１－３）」等という。 Synthesis of resin The compounds (monomers) used in the synthesis of the resin are shown below.

Hereinafter, these monomers will be referred to as "monomers (a1-1-3)" etc. according to their formula numbers.

Synthesis example 3 [Synthesis of resin A1]
Monomer (a1-4-2), monomer (a1-1-1), monomer (a1-2-5), and monomer (a3-2-1) were used as monomers, and their molar ratio [monomer (a1-4 -2): Monomer (a1-1-1): Monomer (a1-2-5): Monomer (a3-2-1)] are mixed in a ratio of 35:5:35:25, and then , To this monomer mixture, 1.5 times the mass of methyl isobutyl ketone was mixed with respect to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile was added as an initiator in an amount of 7 mol% based on the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to perform polymerization. Ta. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer was poured into a large amount of n-heptane to precipitate the resin, and by filtering and collecting it, a resin A1 (copolymer) with a weight average molecular weight of about 5.9 x ¹⁰³ was obtained in a yield of 88. Obtained in %. This resin A1 has the following structural units.

Synthesis Example 4 [Synthesis of resin AX1]
Monomer (a1-1-1), monomer (a1-2-5), and monomer (a3-2-1) were used as monomers, and their molar ratio [monomer (a1-1-1): monomer (a1-2 -5):monomer (a3-2-1)] were mixed in a ratio of 10:50:40, and then added to this monomer mixture by 1.5 times the total mass of all monomers. of methyl isobutyl ketone were mixed. Azobisisobutyronitrile was added as an initiator to the obtained mixture in an amount of 7 mol % based on the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours. The resulting reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate the resin, and the resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, the resulting solution was poured into a methanol/water mixed solvent to precipitate the resin, and this resin was filtered. Resin AX1 (copolymer) having a molecular weight of approximately 5.8×10 ³ was obtained in a yield of 90%. This resin AX1 has the following structural units.

Synthesis example 5 [Synthesis of resin A2]
As monomers, monomer (a1-4-2), monomer (a1-1-2), monomer (a1-2-5), monomer (a2-x) and monomer (a3-2-1) are used, and the mole thereof is The ratio [monomer (a1-4-2): monomer (a1-1-2): monomer (a1-2-5): monomer (a2-x): monomer (a3-2-1)] is 35:5 :30:5:25, and methyl isobutyl ketone was added to this monomer mixture in an amount of 1.5 times the total weight of all monomers. To the obtained mixture, azobisisobutyronitrile was added as an initiator in an amount of 7 mol% based on the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to perform polymerization. Ta. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, and by filtering and collecting it, a resin A2 (copolymer) with a weight average molecular weight of about 5.7 x 10 ³ is obtained in a yield of 82 Obtained in %. This resin A2 has the following structural units.

Synthesis Example 6 [Synthesis of resin AX2]
Monomer (a1-1-2), monomer (a1-2-5), monomer (a2-x), and monomer (a3-2-1) were used as monomers, and their molar ratio [monomer (a1-1-2 ): monomer (a1-2-5): monomer (a2-x): monomer (a3-2-1)] are mixed in a ratio of 9:36:9:46, and further, this monomer mixture 1.5 times the mass of methyl isobutyl ketone was mixed with the total mass of all monomers. Azobisisobutyronitrile was added as an initiator to the obtained mixture in an amount of 7 mol % based on the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours. The resulting reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate the resin, and the resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, the resulting solution was poured into a methanol/water mixed solvent to precipitate the resin, and this resin was filtered. Resin AX2 (copolymer) having a molecular weight of approximately 5.6×10 ³ was obtained in a yield of 86%. This resin AX2 has the following structural units.

Synthesis Example 7 [Synthesis of resin A3]
As monomers, monomer (a1-4-2), monomer (a1-1-3) and monomer (a1-2-6) were used, and their molar ratio [monomer (a1-4-2):monomer (a1-1) -3):monomer (a1-2-6)] were mixed in a ratio of 38:24:38, and then added to this monomer mixture by 1.5 times the total mass of all monomers. of methyl isobutyl ketone were mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator in an amount of 7 mol% based on the total number of moles of all monomers, and polymerization was carried out by heating this at 85 ° C. for about 5 hours. Ta. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered and collected to obtain resin A3 (copolymer) with a weight average molecular weight of approximately 5.6×10 ³ in a yield of 64. Obtained in %. This resin A3 has the following structural units.

<Preparation of resist composition>
As shown in Table 2, a resist composition was prepared by mixing the following components and filtering the resulting mixture through a fluororesin filter with a pore size of 0.2 μm.

Ｄ１：（東京化成工業（株）製）

＜溶剤（Ｅ）＞
プロピレングリコールモノメチルエーテルアセテート ４００部
プロピレングリコールモノメチルエーテル １００部
γ－ブチロラクトン ５部 <Resin (A)>
A1 to A3, AX1, AX2: Resin A1 to Resin A3, Resin AX1, Resin AX2
<Compound (I)>
I-1: Salt represented by formula (I-1) I-2: Salt represented by formula (I-2) I-3: Salt represented by formula (I-3) I-4: Formula Salt represented by (I-4) I-13: Salt represented by formula (I-13) I-92: Salt represented by formula (I-92) I-93: Formula (I-93) I-103: Salt represented by formula (I-103) I-110: Salt represented by formula (I-110) I-111: Salt represented by formula (I-111) I-121: Salt represented by formula (I-121) <Acid generator (B)>
B1-43: Salt represented by formula (B1-43) (synthesized according to the examples of JP-A No. 2016-47815)
<Quencher (C)>
C1: Synthesized by the method described in JP-A-2011-39502

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

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

(Electron beam exposure evaluation of resist composition)
A 6-inch silicon wafer was treated with hexamethyldisilazane at 90° C. for 60 seconds on a direct hot plate. A resist composition was spin-coated onto this silicon wafer so that the thickness of the composition layer was 0.04 μm. Thereafter, it was prebaked for 60 seconds on a direct hot plate at the temperature shown in the "PB" column of Table 2 to form a composition layer. A contact hole pattern (hole pitch 40 nm/hole) was formed on the composition layer formed on the wafer by using an electron beam drawing machine [ELS-F125 125 keV manufactured by Elionix Co., Ltd.] and changing the exposure amount stepwise. 17 nm in diameter) was directly drawn.
After exposure, post-exposure baking was performed for 60 seconds on a hot plate at the temperature shown in the "PEB" column of Table 2, and further paddle development was performed for 60 seconds with a 2.38% by mass tetramethylammonium hydroxide aqueous solution. , a resist pattern was obtained.
In the resist pattern obtained after development, the exposure amount at which the hole diameter formed using the mask was 17 nm was defined as the effective sensitivity.

<CD uniformity (CDU) evaluation>
In terms of effective sensitivity, the hole diameter of a pattern formed using a mask with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was taken as the average hole diameter of one hole. The average hole diameter of a pattern formed using a mask with a hole diameter of 17 nm was measured at 400 locations on the same wafer, and the standard deviation was determined using the population as a population.
The results are shown in Table 3. Values in parentheses indicate standard deviation (nm).


Compared to Comparative Compositions 1 and 2, Compositions 1 to 16 had smaller standard deviations and better CD uniformity (CDU) evaluation.

The resist composition of the present invention provides a resist pattern with good CD uniformity (CDU), and is therefore suitable for microfabrication of semiconductors and is extremely useful industrially.

Claims (8)

A resist composition containing a resin containing a structural unit represented by formula (a2-A) and a structural unit having an acid-labile group, and a salt represented by formula (I).

[In formula (a2-A),
R ^a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may contain a halogen atom.
R ^a51 is a halogen atom, hydroxy group, alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl Represents an oxy 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 is bonded.
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 any integer from 0 to 4. When mb is any integer of 2 or more, a plurality of R ^a51 's may be the same or different. ]

[In formula (I),
R ³ and R ⁴ each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents any integer from 0 to 2, and when z is 2, the plurality of R ³ and R ⁴ may be the same or different.
X ¹ is *-CO-O-, *-O-CO-, *-O-CO-O- or *-O- (* is a bonding site with C(R ³ )(R ⁴ ) or CHCF ₃ ).
L ¹ represents a single bond or a divalent saturated hydrocarbon group having 1 to 28 carbon atoms, and -CH ₂ - contained in the saturated hydrocarbon group is -O-, -S-, -SO ₂ - or -CO- may be substituted.
R ⁵ represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms having a substituent, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (the alicyclic At least one of -CH ₂ - contained in the formula hydrocarbon group is replaced with -O-, -S-, -SO ₂ - or -CO-.
Z ⁺ represents an organic cation. ] 2. The resist composition according to claim 1, wherein z is 1 or 2. ^{Claim 1} or ​ ^​ ​ _​ ​ 2. The resist composition according to 2. L ¹ is a single bond, an alkanediyl group (however, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-), or an alkanediyl group and an alicyclic saturated group. A group formed by combining a hydrocarbon group (However, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-, and a group formed by combining a hydrocarbon group contained in the alicyclic saturated hydrocarbon group) -CH ₂ - may be replaced with -O-, -S-, -SO ₂ - or -CO-.) The resist composition according to any one of claims 1 to 3. Claims 1 to 3, wherein the structural unit having an acid-labile group is at least one type selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2). 4. The resist composition according to any one of 4.

[In formula (a1-1) and formula (a1-2),
L ^a1 and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, k1 represents an integer from 1 to 7, and * represents a bond with -CO- Represents a part.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents any integer from 0 to 14.
n1 represents any integer from 0 to 10.
n1' represents any integer from 0 to 3. ] 6. The resist composition according to claim 1, further comprising a salt that generates an acid having a weaker acidity than the acid generated from the salt represented by formula (I). (1) applying the resist composition according to any one of claims 1 to 6 onto a substrate;
(2) drying the applied composition to form a composition layer;
(3) exposing the composition layer to light;
(4) a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.
A method for manufacturing a resist pattern including: A salt represented by formula (Ia).

[In formula (Ia),
R ³ and R ⁴ each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents any integer from 0 to 2, and when z is 2, the plurality of R ³ and R ⁴ may be the same or different.
X ¹ is *-CO-O-, *-O-CO-, *-O-CO-O- or *-O- (* is a bonding site with C(R ³ )(R ⁴ ) or CHCF ₃ ).
L ¹ represents a single bond or a divalent saturated hydrocarbon group having 1 to 28 carbon atoms, and -CH ₂ - contained in the saturated hydrocarbon group is -O-, -S-, -SO ₂ - or -CO- may be substituted.
R ^5a is an alicyclic hydrocarbon group having a substituent and having 3 to 18 carbon atoms (at least one of -CH ₂ - contained in the alicyclic hydrocarbon group is -O-, -S- , -SO ₂ - or -CO-).
Z ⁺ represents an organic cation. ]