JP7044562B2 - Method for producing salt, acid generator, resist composition and resist pattern - Google Patents

Description

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

特許文献２には、下記式で表される塩を酸発生剤として含有するレジスト組成物が記載されている。

特許文献３には、下記式で表される塩を酸発生剤として含有するレジスト組成物が記載されている。

Patent Document 1 describes a resist composition containing a salt represented by the following formula as an acid generator.

Patent Document 2 describes a resist composition containing a salt represented by the following formula as an acid generator.

Patent Document 3 describes a resist composition containing a salt represented by the following formula as an acid generator.

Japanese Unexamined Patent Publication No. 2012-229206 Japanese Unexamined Patent Publication No. 2012-234155 Japanese Unexamined Patent Publication No. 2007-145822

An object of the present invention is to provide a salt that improves the line edge roughness (LER) of a resist pattern.

［式（Ｉ）中、
Ｑ^１及びＱ^２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。
Ｒ^１及びＲ^２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^１及びＲ^２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－を表し、＊は、Ｃ（Ｒ^１）（Ｒ^２）又はＣ（Ｑ^１）（Ｑ^２）との結合位を表す。
Ａ^１及びＡ^２は、それぞれ独立に、置換基を有してもよい炭素数２～３６の２価の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－Ｃ（＝Ｏ）－又は－ＳＯ_２－に置き換わっていてもよい。
Ｒ^３及びＲ^４は、それぞれ独立に、水素原子又は炭素数１～６の飽和炭化水素基を表す。
Ｒ^５は、ヒドロキシ基、式（ａａ１）又は式（ａａ２）で表される基を表す。

（式（ａａ１）中、
Ｒ^１２、Ｒ^１３、Ｒ^１４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^１２及びＲ^１３は互いに結合してそれらが結合する炭素原子とともに炭素数３～２０の２価の脂環式炭化水素基を形成する。
ｎａは、０又は１を表す。
式（ａａ２）中、
Ｒ^１５及びＲ^１６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^１７は、炭素数１～２０の炭化水素基を表すか、Ｒ^１６及びＲ^１７は互いに結合してそれらが結合する炭素原子及び酸素原子とともに炭素数３～２０の２価の複素環基を形成し、該炭化水素基及び該２価の複素環基に含まれる－ＣＨ₂－は、－Ｏ－又は－Ｓ－で置き換わってもよい。）
Ｚ^＋は、有機カチオンを表す。］
〔２〕Ｘ^１が、＊－ＣＯ－Ｏ－である〔１〕に記載の塩。
〔３〕Ａ^１及びＡ^２が、それぞれ独立に、炭素数３～１８の２価の脂環式炭化水素基又は炭素数３～１８の脂環式炭化水素基と炭素数１～１８のアルカンジイル基とから形成される２価の炭化水素基である〔１〕又は〔２〕に記載の塩。
〔４〕Ｒ^５が、水素原子である〔１〕～〔３〕のいずれか１つに記載の塩。
〔５〕〔１〕～〔４〕のいずれか１つに記載の塩を含有する酸発生剤。
〔６〕〔５〕に記載の酸発生剤と酸不安定基を有する構造単位を含む樹脂とを含有するレジスト組成物。
〔７〕酸発生剤から発生する酸よりも酸性度の低い酸を発生する塩をさらに含有する〔６〕に記載のレジスト組成物。
〔８〕（１）〔６〕又は〔７〕に記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層を露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A salt represented by the formula (I).

[In formula (I),
^Q1 and ^Q2 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
R ¹ and R ² independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² may be the same or different from each other.
X ¹ represents * -CO-O-, * -O-CO-, * -O-CO-O- or * -O-, and * is C (R ¹ ) (R ² ) or C (Q). ¹ ) Represents the binding position with ( ^Q2 ).
A ¹ and A ² each independently represent a divalent hydrocarbon group having 2 to 36 carbon atoms which may have a substituent, and -CH _2- contained in the hydrocarbon group is -O-. , -S-, -C (= O)-or-SO ₂ -may be replaced.
R ³ and R ⁴ each independently represent a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms.
R ⁵ represents a hydroxy group, a group represented by the formula (aa1) or the formula (aa2).

(In equation (aa1),
R ¹² , R ¹³ and R ¹⁴ independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group combining these groups, or R ¹² and R ¹³ respectively. Bonds to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
na represents 0 or 1.
In formula (aa2),
R ¹⁵ and R ¹⁶ independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ¹⁷ represents a hydrocarbon group having 1 to 20 carbon atoms, or R ¹⁶ and R ¹⁷ represent each other. A divalent heterocyclic group having 3 to 20 carbon atoms is formed together with the carbon atom and the oxygen atom to which they are bonded, and the hydrocarbon group and -CH _2- contained in the divalent heterocyclic group are It may be replaced by -O- or -S-. )
Z ⁺ represents an organic cation. ]
[2] The salt according to [1], wherein X ¹ is * -CO-O-.
[3] A ¹ and A ² independently have a divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms and an alkane having 1 to 18 carbon atoms. The salt according to [1] or [2], which is a divalent hydrocarbon group formed from a diyl group.
[4] The salt according to any one of [1] to [ ³ ], wherein R5 is a hydrogen atom.
[5] The acid generator containing the salt according to any one of [1] to [4].
[6] A resist composition containing the acid generator according to [5] and a resin containing a structural unit having an acid unstable group.
[7] The resist composition according to [6], which further contains a salt that generates an acid having a lower acidity than the acid generated from the acid generator.
[8] (1) A step of applying the resist composition according to [6] or [7] onto a substrate,
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
(4) A method for producing a resist pattern, which comprises a step of heating the composition layer after exposure and (5) a step of developing the composition layer after heating.

According to the present invention, a resist pattern can be manufactured with good line edge roughness (LER).

In the present specification, the "(meth) acrylic monomer" has a structure of "CH ₂ = CH-C (= O)-" or "CH ₂ = C (CH ₃ ) -C (= O)-". It means at least one kind of monomer having. Similarly, "(meth) acrylate" and "(meth) acrylic acid" mean "at least one of acrylate and methacrylate" and "at least one of acrylic acid and methacrylic acid", respectively. Notations such as "(meth) acryloyl" have the same meaning.
In the present specification, the "solid content of the resist composition" means the total amount of the components excluding the solvent (E) described later from the total amount of the resist composition.

［式（Ｉ）中、
Ｑ^１及びＱ^２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。
Ｒ^１及びＲ^２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^１及びＲ^２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－を表し、＊は、Ｃ（Ｒ^１）（Ｒ^２）又はＣ（Ｑ^１）（Ｑ^２）との結合位を表す。
Ａ^１及びＡ^２は、それぞれ独立に、置換基を有してもよい炭素数２～３６の２価の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－Ｃ（＝Ｏ）－又は－ＳＯ_２－に置き換わっていてもよい。
Ｒ^３及びＲ^４は、それぞれ独立に、水素原子又は炭素数１～６の飽和炭化水素基を表す。
Ｒ^５は、ヒドロキシ基、式（ａａ１）又は式（ａａ２）で表される基を表す。

（式（ａａ１）中、
Ｒ^１２、Ｒ^１３、Ｒ^１４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^１２及びＲ^１３は互いに結合してそれらが結合する炭素原子とともに炭素数３～２０の２価の脂環式炭化水素基を形成する。
ｎａは、０又は１を表す。
式（ａａ２）中、
Ｒ^１５及びＲ^１６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^１７は、炭素数１～２０の炭化水素基を表すか、Ｒ^１６及びＲ^１７は互いに結合してそれらが結合する炭素原子及び酸素原子とともに炭素数３～２０の２価の複素環基を形成し、該炭化水素基及び該２価の複素環基に含まれる－ＣＨ₂－は、－Ｏ－又は－Ｓ－で置き換わってもよい。）
Ｚ^＋は、有機カチオンを表す。］ [Salt represented by formula (I) and anions constituting it]
The salt of the present invention is a salt represented by the formula (I) (hereinafter, may be referred to as “salt (I)”).

[In formula (I),
^Q1 and ^Q2 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
R ¹ and R ² independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² may be the same or different from each other.
X ¹ represents * -CO-O-, * -O-CO-, * -O-CO-O- or * -O-, and * is C (R ¹ ) (R ² ) or C (Q). ¹ ) Represents the binding position with ( ^Q2 ).
A ¹ and A ² each independently represent a divalent hydrocarbon group having 2 to 36 carbon atoms which may have a substituent, and -CH _2- contained in the hydrocarbon group is -O-. , -S-, -C (= O)-or-SO ₂ -may be replaced.
R ³ and R ⁴ each independently represent a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms.
R ⁵ represents a hydroxy group, a group represented by the formula (aa1) or the formula (aa2).

(In equation (aa1),
R ¹² , R ¹³ , and R ¹⁴ independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group combining these groups, or R ¹² and R ¹³ respectively. Bonds to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
na represents 0 or 1.
In formula (aa2),
R ¹⁵ and R ¹⁶ independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ¹⁷ represents a hydrocarbon group having 1 to 20 carbon atoms, or R ¹⁶ and R ¹⁷ represent each other. A divalent heterocyclic group having 3 to 20 carbon atoms is formed together with the carbon atom and the oxygen atom to which they are bonded, and the hydrocarbon group and -CH _2- contained in the divalent heterocyclic group are It may be replaced by -O- or -S-. )
Z ⁺ represents an organic cation. ]

The perfluoroalkyl groups of ^Q1 , ^Q2 , ^R1 and ^R2 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group and perfluorotert-butyl group. , Perfluoropentyl group, perfluorohexyl group and the like.
^Q1 and ^Q2 are independently, preferably a trifluoromethyl group or a fluorine atom, and more preferably a fluorine atom.
R ¹ and R ² are independent, preferably hydrogen or fluorine atoms, respectively.
z is preferably 0.

X ¹ is * -CO-O- or * -O-CO-O- (* represents a bond with C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² )). It is preferable to have.

Examples of the divalent hydrocarbon group having 2 to 36 carbon atoms of A ¹ and A ² include an alcandiyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and a divalent aromatic hydrocarbon. Examples thereof include a hydrogen group, and a divalent hydrocarbon group in which two or more of these groups are combined may be used.

^The alkanediyl groups in A1 and ^A2 include ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, and 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, Linear alkanediyl group such as 12-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- Examples thereof include 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.
Examples of the monocyclic divalent alicyclic saturated hydrocarbon group include cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1, Cycloalkandyl groups such as 5-diyl groups can be mentioned.
The polycyclic divalent alicyclic saturated hydrocarbon group includes norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-. Examples include diyl groups.
Examples of the divalent aromatic hydrocarbon group include a phenylene group, a naphthylene group, an anthrylene group, a p-methylphenylene group, a p-tert-butylphenylene group, a p-adamantylphenylene group, a trill group, a xylylene group, a cumenylene group and a mesitylene. Examples thereof include an aryl group such as a group, a biphenylene group, a phenanthrylene group, a 2,6-diethylphenylene group and a 2-methyl-6-ethylphenylene group.
As a divalent hydrocarbon group in which two or more kinds are combined, a divalent hydrocarbon group (-) formed from an alicyclic hydrocarbon group having 3 to 18 carbon atoms and an alkanediyl group having 1 to 18 carbon atoms. Cyclo-alkanediyl-alkanediyl-,-alkanediyl-cycloalkandyl-alkanediyl-), a divalent divalent formed from an aromatic hydrocarbon group with 6-18 carbon atoms and an alkanediyl group with 1-18 carbon atoms. Hydrocarbon groups (-alkanediyl-aromatic hydrocarbon groups-) and the like can be mentioned.

The substituents of the hydrocarbon groups A ¹ and A ² include a hydroxy group, a cyano group, a carboxy group, an alkoxy group having 1 to 12 carbon atoms, an alkylcarbonyl group having 2 to 13 carbon atoms, and a substituent having 2 to 13 carbon atoms. Examples thereof include an alkylcarbonyloxy group and a group in which two or more of these groups are combined.
Examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group.
Examples of the alkylcarbonyl group having 2 to 13 carbon atoms include an acetyl group, a propionyl group and a butyryl group.
Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
The divalent hydrocarbon group having 2 to 36 carbon atoms represented by A ¹ and A ² may have one substituent or a plurality of substituents.

-CH _2- contained in the divalent hydrocarbon group having 2 to 36 carbon atoms of A ¹ and A ² is replaced with -O-, -S-, -C (= O)-or -SO _2- . May be.
When a divalent hydrocarbon group having 2 to 36 carbon atoms represented by A ¹ and A ² has a substituent, or -CH _2- contained in the hydrocarbon group is -O-, -S-, -C. When (= O)-or -SO _2- is replaced, the number of carbon atoms before the replacement is defined as the number of carbon atoms of the hydrocarbon group.

The divalent hydrocarbon group having 2 to 36 carbon atoms represented by A ¹ is a divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms or a divalent alicyclic hydrocarbon having 3 to 18 carbon atoms. It is preferably a divalent hydrocarbon group formed from a group and an alcandiyl group having 1 to 18 carbon atoms, preferably a cyclohexyldiyl group, an adamantandiyl group, and * 1-A ¹¹ -X ^1A -A ^12- * 2. It is more preferable that the group is represented by * 1-A ¹³ -X ^1A- * 2, and the group is represented by * 1-X ^1A -A ^14- * 2. In particular, the divalent hydrocarbon group having 2 to 36 carbon atoms represented by A ¹ and A ² preferably contains a polycyclic alicyclic hydrocarbon group, and both A ¹ and A ² are polycyclic. Those containing an alicyclic hydrocarbon group are more preferable.
X ^1A represents a divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms, and is preferably a cyclohexanediyl group and an adamantandiyl group.
A ¹¹ , A ¹² , A ¹³ and A ¹⁴ each independently represent an alkanediyl group having 1 to 17 carbon atoms. It is preferable that A ¹¹ , A ¹² , A ¹³ and A ¹⁴ are each independently an alkanediyl group having 1 to 6 carbon atoms.
* 1 represents a bond with X ¹ and * 2 represents a bond with -O-.

The divalent hydrocarbon group having ² to 36 carbon atoms in A2 is a divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms and carbon. It is preferably a divalent hydrocarbon group formed from an alcandiyl group having the number 1 to 18, and is represented by a cyclohexyldiyl group, an adamantandiyl group, and * 3-A ¹⁵ -X ^11A -A ^16- * 4. A group represented by * 3-A ¹⁷ -X ^11A- * 4, and a group represented by * 3-X ^11A -A ^18- * 4 are more preferable.
X ^11A represents a divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms.
A ¹⁵ , A ¹⁶ , A ¹⁷ and A ¹⁸ each independently represent an alkanediyl group having 1 to 17 carbon atoms. It is preferable that A ¹⁵ , A ¹⁶ , A ¹⁷ and A ¹⁸ are each independently an alkanediyl group having 1 to 6 carbon atoms.
* 3 represents a bond with -O-, and * ⁴ represents a bond with R5.

Examples of the saturated hydrocarbon group having 1 to 6 carbon atoms of R ³ and R ⁴ include a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group and a hexyl group. Alkyl groups of: cyclopentyl groups, cycloalkyl groups such as cyclohexyl groups; and groups formed by combining these groups can be mentioned.
R ³ and R ⁴ are each independently preferably a hydrogen atom, a methyl group or an ethyl group, more preferably a hydrogen atom or a methyl group, and one is a hydrogen atom and the other is a methyl group. More preferred.

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、ノルボルニルエチル基等が挙げられる。 Examples of the alkyl group of R ¹² to R ¹⁴ include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group and an n-octyl group.
The alicyclic hydrocarbon group of R ¹² to R ¹⁴ may be either a monocyclic or polycyclic group. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups (* indicates a bond). The alicyclic hydrocarbon group of R ¹² to R ¹⁴ is preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms.

Examples of the group in which the alkyl group and the alicyclic hydrocarbon group are combined include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, a norbornylethyl group and the like. Can be mentioned.

Examples of -C (R ¹² ) (R ¹³ ) (R ¹⁴ ) in the case where R ¹² and R ¹³ are bonded to each other to form a divalent alicyclic hydrocarbon group include the following groups. The divalent alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

Examples of the group represented by the formula (aa1) include a tert-butyl group, a 2-alkyladamantan-2-yl group, a 1-alkylcyclopentane-1-yl group, a 1-alkylcyclohexane-1-yl group and the like. Be done.

Ｘは酸素原子又は硫黄原子を表す。
Ｒ^１５及びＲ^１６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。 Examples of the hydrocarbon groups of R ¹⁵ to R ¹⁷ include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same as above.
Examples of the aromatic hydrocarbon group 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 and biphenyl. Examples thereof include an aryl group such as a group, a phenanthryl group, a 2,6-diethylphenyl group and a 2-methyl-6-ethylphenyl group.
Examples of the combined group include a group combining the above-mentioned alkyl group and an alicyclic hydrocarbon group, an aralkyl group such as a benzyl group, and an aryl-cyclohexyl group such as a phenylcyclohexyl group.
Examples of the divalent heterocyclic group formed by the R ¹⁶ and R ¹⁷ bonded to each other together with the carbon atom and the oxygen atom to which they are bonded include the following groups. * Represents a bond.

X represents an oxygen atom or a sulfur atom.
It is preferable that at least one of R ¹⁵ and R ¹⁶ is a hydrogen atom.

Examples of the group represented by the formula (aa2) include the following groups. * Represents a bond.

Examples of the anion in the salt (I) include anions represented by the following formulas (Ia-1) to (Ia-50). Among them, formulas (Ia-1) to formulas (Ia-11), formulas (Ia-13) to formulas (Ia-20), formulas (Ia-22), formulas (Ia-23) to formulas (Ia-33). , Formulas (Ia-35) to (Ia-42), formulas (Ia-44), formulas (Ia-49) to formulas (Ia-58) are preferred, and formulas (Ia-1), Formula (Ia-2), formula (Ia-13) to formula (Ia-16), formula (Ia-23), formula (Ia-24), formula (Ia-35) to formula (Ia-38), formula. Anions represented by the formulas (Ia-49) to (Ia-58) are more preferable.

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

[In equations (b2-1) to (b2-4),
R ^b4 to R ^b6 independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. It may be substituted, and the hydrogen atom contained in the alicyclic hydrocarbon group is a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms or a glycidyloxy group. It may be substituted, and 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 be combined to form a ring containing a sulfur atom to which they are bonded, and -CH _2- contained in the ring is -O-, -S (= O)-. Alternatively, it may be replaced with −C (= O) −.
R ^b7 and R ^b8 independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.
When m2 is 2 or more, the plurality of R ^b7s may be the same or different, and when n2 is 2 or more, the plurality of R ^b8s may be the same or different.
R ^b9 and R ^b10 independently represent an aliphatic hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may be combined to form a ring containing a sulfur atom to which they are bonded, and -CH _2- contained in the ring is -O-, -S (= O)-. Alternatively, it may be replaced with −C (= O) −.
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and is contained in the aliphatic hydrocarbon group. The hydrogen atom 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 an alkoxy group having 1 to 12 carbon atoms or 1 to 12 carbon atoms. It may be substituted with 12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may be together to form a ring containing —C—C (= O) — to which they are bonded, and —CH ₂ − contained in the ring is —O—. , -S (= O)-or-C (= O)-may be replaced.
R ^b13 to R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents —S— or —O—.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represent an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13s may be the same or different, when p2 is 2 or more, the plurality of R ^b14s may be the same or different, and when q2 is 2 or more. , The plurality of R ^b15s may be the same or different, and when r2 is 2 or more, the plurality of R ^b16s may be the same or different, and when s2 is 2 or more, the plurality of R ^b17s may be different. It may be the same or different, and when t2 is 2 or more, the plurality of R ^b18s may be the same or different. ]

Among the cations (b2-1) to cations (b2-4), cations (b2-1) are preferable.
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.

中でも、式（ｂ２－ｃ－１）、（ｂ２－ｃ－１０）、（ｂ２－ｃ－１２）、（ｂ２－ｃ－１４）、（ｂ２－ｃ－２７）、（ｂ２－ｃ－３０）及び（ｂ２－ｃ－３１）で表されるカチオンが好ましい。 Examples of the cation (b2-4) include the following cations.

Among them, the formulas (b2-c-1), (b2-c-10), (b2-c-12), (b2-c-14), (b2-c-27), (b2-c-30). And the cation represented by (b2-c-31) are preferable.

<Specific example of salt (I)>
The salt (I) is a combination of the above-mentioned anions and organic cations. These anions and organic cations can be arbitrarily combined. Specific examples of the salt (I) are shown in the table below.

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

Among them, the salt (I) includes salt (I-1), salt (I-2), salt (I-9), salt (I-23), salt (I-24), salt (I-49), and the like. Salt (I-50), salt (I-51), salt (I-52), salt (I-73), salt (I-74), salt (I-99), salt (I-100), salt (I-101), salt (I-102), salt (I-123), salt (I-124), salt (I-149), salt (I-150), salt (I-151), salt ( I-152), salt (I-173), salt (I-174), salt (I-199), salt (I-200), salt (I-201), salt (I-202), salt (I) -223), salt (I-224), salt (I-249), salt (I-250), salt (I-251), salt (I-252), salt (I-273), salt (I-) 274), salt (I-299), salt (I-300), salt (I-301), salt (I-302), salt (I-323), salt (I-324), salt (I-349). ), Salt (I-350) and salt (I-351) to salt (I-406) are preferred.

［式中、Ｑ¹、Ｑ²、Ｒ¹、Ｒ²、Ｒ^３、Ｒ^１５、Ｒ^１６、Ｒ^１７、Ａ¹、Ａ²、ｚ及びＺ^＋は上記と同じ意味を表す。Ｒ^１５´は、Ｒ^１５から水素原子を除いた基を表す。］
反応は、５℃～８０℃の温度範囲で、０．５～２４時間行うことが好ましい。
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。
触媒としては、例えば、カンファースルホン酸又は以下で表される塩などが挙げられる。

<Manufacturing method of salt (I)>
In the salt (I), the salt (salt represented by the formula (I1)) on which R5 is a group represented by the formula ( ^aa2 ) is, for example, a salt represented by the formula (I1-a) and a salt represented by the formula (I1-a). It can be obtained by reacting the compound represented by (I1-b) in the presence of a catalyst in a solvent.

[In the formula, Q ¹ , Q ² , R ¹ , R ² , R ³ , R ¹⁵ , R ¹⁶ , R ¹⁷ , A ¹ , A ² , z and Z ⁺ have the same meanings as above. R ^{15'represents} a group obtained by removing a hydrogen atom from R ¹⁵ . ]
The reaction is preferably carried out in a temperature range of 5 ° C to 80 ° C for 0.5 to 24 hours.
Examples of the solvent include chloroform, acetonitrile and the like.
Examples of the catalyst include camphorsulfonic acid or a salt represented by the following.

Examples of the compound represented by the formula (I1-b) include compounds represented by the following formula.

［式中、Ｑ¹、Ｑ²、Ｒ¹、Ｒ²、Ｒ^３、Ｒ^３、Ｒ^１５、Ｒ^１５´、Ｒ^１６、ｚ、Ａ¹、Ａ^２及びＺ^＋は上記と同じ意味を表す。Ｒ^４´は、Ｒ^４から水素原子を除いた基を表す。］
反応は、５℃～８０℃の温度範囲で、０．５～２４時間行うことが好ましい。
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。
触媒としては、例えば、以下で表される塩などが挙げられる。

The salt represented by the formula (I1-a) is, for example, a salt represented by the formula (I1-c) and a compound represented by the formula (I1-d) in a solvent in the presence of a catalyst. , Can be obtained by reacting.

[In the formula, Q ¹ , Q ² , R ¹ , R ² , R ³ , R ³ , R ¹⁵ , R ^15' , R ¹⁶ , z, A ¹ , A ² and Z ⁺ have the same meanings as above. R ^4'represents a group obtained by removing a hydrogen atom from R ⁴ . ]
The reaction is preferably carried out in a temperature range of 5 ° C to 80 ° C for 0.5 to 24 hours.
Examples of the solvent include chloroform, acetonitrile and the like.
Examples of the catalyst include salts represented below.

Examples of the compound represented by the formula (I1-d) include compounds represented by the following formula.

［式中、Ｑ¹、Ｑ²、Ｒ¹、Ｒ²、Ｒ^３、Ｒ^４´は、ｚ、Ｘ¹、Ａ¹及びＺ^＋は上記と同じ意味を表す。Ｘ^1´は、Ｘ¹からＡ¹結合位の酸素原子を除いた基を表す。］
反応は、５℃～８０℃の温度範囲で、０．５～２４時間行うことが好ましい。
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。
触媒としては、カルボニルジイミダゾール、水酸化カリウムなどが挙げられる。 The salt represented by the formula (I1-c) is, for example, a salt represented by the formula (I1-e) and a compound represented by the formula (I1-f) in the presence of a catalyst in a solvent. It can be obtained by reacting.

[In the formula, Q ¹ , Q ² , R ¹ , R ² , R ³ , R ^4'represent the same meanings as above for z, X ¹ , A ¹ and Z ⁺ . X ^1'represents a group from X ¹ excluding the oxygen atom at the A ¹ bond position. ]
The reaction is preferably carried out in a temperature range of 5 ° C to 80 ° C for 0.5 to 24 hours.
Examples of the solvent include chloroform, acetonitrile and the like.
Examples of the catalyst include carbonyldiimidazole, potassium hydroxide and the like.

式（Ｉ１－ｆ）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る。

Examples of the salt represented by the formula (I1-e) include salts represented by the following, with reference to the methods described in JP-A-2007-197718 and JP-A-2012-193170. Can be manufactured.

Examples of the compound represented by the formula (I1-f) include compounds represented by the following formula.

［式中、Ｑ¹、Ｑ²、Ｒ¹、Ｒ²、Ｒ^３、Ｒ^１２、Ｒ^１３、Ｒ^１４、Ａ¹、Ａ²、ｚ及びＺ^＋は上記と同じ意味を表す。］
反応は、５℃～８０℃の温度範囲で、０．５～２４時間行うことが好ましい。
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。
塩基としては、例えば、トリエチルアミン、ピリジン、ジメチルアミノピリジンなどが挙げられる。
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る。

In the salt (I), the salt (salt represented by the formula (I2)) ^on which R5 is a group represented by the formula (aa1) is, for example, a salt represented by the formula (I2-a) and a salt represented by the formula (I2-a). It can be obtained by reacting the compound represented by (I2-b) in the presence of a base in a solvent.

[In the formula, Q ¹ , Q ² , R ¹ , R ² , R ³ , R ¹² , R ¹³ , R ¹⁴ , A ¹ , A ² , z and Z ⁺ have the same meanings as above. ]
The reaction is preferably carried out in a temperature range of 5 ° C to 80 ° C for 0.5 to 24 hours.
Examples of the solvent include chloroform, acetonitrile and the like.
Examples of the base include triethylamine, pyridine, dimethylaminopyridine and the like.
Examples of the compound represented by the formula (I2-b) include compounds represented by the following formula.

［式中、Ｑ¹、Ｑ²、Ｒ¹、Ｒ²、Ｒ^３、Ｒ^３、Ｒ^１５、Ｒ^１５´、Ｒ^１６、ｚ、Ａ¹、Ａ^２及びＺ^＋は上記と同じ意味を表す。Ｒ^４´は、Ｒ^４から水素原子を除いた基を表す。］
反応は、５℃～８０℃の温度範囲で、０．５～２４時間行うことが好ましい。
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。
触媒としては、例えば、以下で表される塩などが挙げられる。

The salt represented by the formula (I2-a) is, for example, a salt represented by the formula (I1-c) and a compound represented by the formula (I2-d) in a solvent in the presence of a catalyst. , Can be obtained by reacting.

[In the formula, Q ¹ , Q ² , R ¹ , R ² , R ³ , R ³ , R ¹⁵ , R ^15' , R ¹⁶ , z, A ¹ , A ² and Z ⁺ have the same meanings as above. R ^4'represents a group obtained by removing a hydrogen atom from R ⁴ . ]
The reaction is preferably carried out in a temperature range of 5 ° C to 80 ° C for 0.5 to 24 hours.
Examples of the solvent include chloroform, acetonitrile and the like.
Examples of the catalyst include salts represented below.

Examples of the compound represented by the formula (I2-d) include compounds represented by the following formula.

［式中、Ｑ¹、Ｑ²、Ｒ¹、Ｒ²、Ｒ^３、Ｒ^４、Ｒ^１５、Ｒ^１６、Ｒ^１７、Ａ¹、Ａ²、ｚ及びＺ^＋は上記と同じ意味を表す。Ｒ^１５´は、Ｒ^１５から水素原子を除いた基を表す。］
反応は、５℃～８０℃の温度範囲で、０．５～２４時間行うことが好ましい。
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。
触媒としては、例えば、カンファースルホン酸又は以下で表される塩などが挙げられる。

In the salt (I), the salt from which X ¹ is * -CO-O- and R ⁵ is the group represented by the formula (aa2) (the salt represented by the formula (I3)) is, for example, the formula. It can be obtained by reacting the salt represented by (I3-a) with the compound represented by the formula (I3-b) in the presence of a catalyst in a solvent.

[In the formula, Q ¹ , Q ² , R ¹ , R ² , R ³ , R ⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , A ¹ , A ² , z and Z ⁺ have the same meanings as above. R ^{15'represents} a group obtained by removing a hydrogen atom from R ¹⁵ . ]
The reaction is preferably carried out in a temperature range of 5 ° C to 80 ° C for 0.5 to 24 hours.
Examples of the solvent include chloroform, acetonitrile and the like.
Examples of the catalyst include camphorsulfonic acid or a salt represented by the following.

［式中、Ｑ¹、Ｑ²、Ｒ¹、Ｒ²、Ｒ^３、Ｒ^４、Ｒ^３、Ｒ^１５、Ｒ^１５´、Ｒ^１６、ｚ、Ａ¹、Ａ^２及びＺ^＋は上記と同じ意味を表す。Ｒ^４´は、Ｒ^４から水素原子を除いた基を表す。］
反応は、５℃～８０℃の温度範囲で、０．５～２４時間行うことが好ましい。
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。
触媒としては、例えば、以下で表される塩などが挙げられる。

The salt represented by the formula (I3-a) is, for example, a salt represented by the formula (I3-c) and a compound represented by the formula (I1-d) in a solvent in the presence of a catalyst. , Can be obtained by reacting.

[In the formula, Q ¹ , Q ² , R ¹ , R ² , R ³ , R ⁴ , R ³ , R ¹⁵ , R ^15' , R ¹⁶ , z, A ¹ , A ² and Z ⁺ have the same meaning as above. Represents. R ^4'represents a group obtained by removing a hydrogen atom from R ⁴ . ]
The reaction is preferably carried out in a temperature range of 5 ° C to 80 ° C for 0.5 to 24 hours.
Examples of the solvent include chloroform, acetonitrile and the like.
Examples of the catalyst include salts represented below.

［式中、Ｑ¹、Ｑ²、Ｒ¹、Ｒ²、Ｒ^３、Ｒ^４、Ｒ^４´、ｚ、Ａ¹及びＺ^＋は上記と同じ意味を表す。］
反応は、５℃～８０℃の温度範囲で、０．５～２４時間行うことが好ましい。
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。 The salt represented by the formula (I3-c) is obtained by, for example, reacting a salt represented by the formula (I3-e) with a compound represented by the formula (I1-f) in a solvent. Obtainable.

[In the formula, Q ¹ , Q ² , R ¹ , R ² , R ³ , R ⁴ , R 4', ^z , A ¹ and Z ⁺ have the same meanings as above. ]
The reaction is preferably carried out in a temperature range of 5 ° C to 80 ° C for 0.5 to 24 hours.
Examples of the solvent include chloroform, acetonitrile and the like.

Examples of the salt represented by the formula (I1-e) include compounds represented by the following.

［式中、Ｑ¹、Ｑ²、Ｒ¹、Ｒ²、Ｒ^３、Ｒ^４、Ｒ^１５、Ｒ^１６、Ｒ^１７、Ａ¹、Ａ²、ｚ及びＺ^＋は上記と同じ意味を表す。］
反応は、５℃～８０℃の温度範囲で、０．５～２４時間行うことが好ましい。
溶媒としては、クロロホルム、アセトニトリル、メタノール等が挙げられる。
酸触媒としては、例えば、塩酸、ｐ－トルエンスルホン酸などが挙げられる。 In the salt (I), the salt in which X ¹ is * -CO-O- and R ⁵ is a hydroxy group (salt represented by the formula (I4)) is represented by the formula (I3), for example. The salt can be obtained by reacting in a solvent in the presence of an acid catalyst.

[In the formula, Q ¹ , Q ² , R ¹ , R ² , R ³ , R ⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , A ¹ , A ² , z and Z ⁺ have the same meanings as above. ]
The reaction is preferably carried out in a temperature range of 5 ° C to 80 ° C for 0.5 to 24 hours.
Examples of the solvent include chloroform, acetonitrile, methanol and the like.
Examples of the acid catalyst include hydrochloric acid, p-toluenesulfonic acid and the like.

[Acid generator]
The acid generator of the present invention contains a salt (I). The acid generator of the present invention may contain the salt (I) alone, or may contain two or more kinds of the salt (I).
The acid generator of the present invention may contain an acid generator known in the resist field (hereinafter, may be referred to as “acid generator (B)”) other than the salt (I).
In the acid generator, the content ratio (mass ratio; salt (I): acid generator (B)) of the salt (I) and the acid generator (B) is usually 100: 0 to 0: 100 or It is 1:99 to 99: 1, preferably 2:98 to 98: 2, more preferably 5:95 to 95: 5, and even more preferably 10:90 to 90:10.

<Acid generator (B)>
The acid generator is classified into a nonionic type and an ionic type, and any of them may be used in the acid generator (B) of the resist composition of the present invention. Nonionic acid generators include organic halides and sulfonate esters (eg 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonates), sulfones (eg, disulfones, ketosulfones, sulfonyldiazomethanes) and the like. Examples of the ionic acid generator include an ionic acid generator composed of a combination of a known cation and a known anion, and an onium salt containing an onium cation (for example, a diazonium salt, a phosphonium salt, a sulfonium salt, an iodonium salt) is represented. It is a target. Examples of the onium salt anion include a sulfonic acid anion, a sulfonylimide anion, and a sulfonylmethide anion.

Examples of the acid generator (B) include JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, and Japanese Patent Publication No. 63-163452. Kaisho 62-153853, JP-A-63-146029, US Patent No. 3,779,778, US Patent No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. A compound that generates an acid by radiation described in JP2013-68914, an acid generator described in JP2013-3155, JP2013-11905, and the like can be used. Further, a compound produced by a known method may be used.

［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。
Ｚ１^＋は、有機カチオンを表す。］ The acid generator (B) is preferably a fluorine-containing acid generator, and more preferably a salt represented by the formula (B1) (hereinafter, may be 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 which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and is contained in the alicyclic hydrocarbon group. CH _2- may be replaced with —O—, —S (O) ₂ -or —CO—.
Z1 ⁺ represents an organic cation. ]

The perfluoroalkyl groups represented by Q ^b1 and Q ^b2 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and Examples thereof include a perfluorohexyl group.
It is preferable that Q ^b1 and Q ^b2 are independently fluorine atoms or trifluoromethyl groups, and it is more preferable that both are fluorine atoms.

Examples of the divalent saturated hydrocarbon group in L ^b1 include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. It may be a group formed by combining two or more kinds of groups.
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, Nonan-1,9-Diyl group, Decan-1,10-Diyl group, Undecan-1,11-Diyl group, Dodecan-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. Alcandiyl 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, 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, etc. Valuable 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. The group etc. can be mentioned.

Examples of the group in which -CH _2- replaced by -O- or -CO- contained in the divalent saturated hydrocarbon group represented by L ^b1 are represented by the formulas (b1-1) to (b1-3). The group represented by any of the above is mentioned. In formulas (b1-1) to formulas (b1-3) and specific examples thereof, formulas (b1-4) to formulas (b1-11), * 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。］

[In equation (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 hydrocarbon group may be substituted. -CH _2- contained in the hydrocarbon group may be replaced with -O- or -CO-.
However, the total number of carbon atoms of L ^b2 and L ^b3 is 22 or less.
In equation (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 hydrocarbon group may be substituted. -CH _2- contained in the hydrocarbon group may be replaced with -O- or -CO-.
However, the total number of carbon atoms of L ^b4 and L ^b5 is 22 or less.
In equation (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 hydrocarbon group may be substituted. -CH _2- contained in the hydrocarbon group may be replaced with -O- or -CO-.
However, the total number of carbon atoms of L ^b6 and L ^b7 is 23 or less. ]

In the formulas (b1-1) to (b1-3), when _-CH2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the number of carbon atoms before the replacement is the saturated hydrocarbon. The number of carbon atoms in the hydrogen 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-.

The group in which _-CH2- in the divalent saturated hydrocarbon group represented by L ^b1 is replaced with -O- or -CO- is represented by the formula (b1-1) or the formula (b1-3). Groups are preferred.

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

[In equation (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 equation (b1-5),
L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and 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 equation (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 equation (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total number of carbon atoms of L ^b13 to L ^b15 is 19 or less.
In equation (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total number of carbon atoms 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, and 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 formula (b1-3) include groups represented by the formulas (b1-9) to (b1-11).

In equation (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. May be good. -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 replaced with a hydroxy group.
However, the total carbon number of L ^b19 and L ^b20 is 23 or less.
In equation (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. May be good. -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 replaced with a hydroxy group.
However, the total carbon number of L ^b21 , L ^b22 and L ^b23 is 21 or less.
In equation (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. May be good. -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 replaced with a hydroxy group.
However, the total carbon number of L ^b24 , L ^b25 and L ^b26 is 21 or less.

In the formulas (b1-9) to (b1-11), when the hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the number of carbon atoms before the replacement is the saturated hydrocarbon group. The number of carbon atoms in.

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

（＊はＹとの結合部位を表す。） Examples of the group represented by the formula (b1-4) include the following.

(* Represents the binding site with Y.)

（＊はＹとの結合部位を表す。） Examples of the group represented by the formula (b1-5) include the following.

(* Represents the binding site with Y.)

（＊はＹとの結合部位を表す。） Examples of the group represented by the formula (b1-6) include the following.

(* Represents the binding site with Y.)

（＊はＹとの結合部位を表す。） Examples of the group represented by the formula (b1-7) include the following.

(* Represents the binding site with Y.)

（＊はＹとの結合部位を表す。） Examples of the group represented by the formula (b1-8) include the following.

(* Represents the binding site with Y.)

（＊はＹとの結合部位を表す。） Examples of the group represented by the formula (b1-2) include the following.

(* Represents the binding site with Y.)

（＊はＹとの結合部位を表す。） Examples of the group represented by the formula (b1-9) include the following.

(* Represents the binding site with Y.)

（＊はＹとの結合部位を表す。） Examples of the group represented by the formula (b1-10) include the following.

(* Represents the binding site with Y.)

（＊はＹとの結合部位を表す。） Examples of the group represented by the formula (b1-11) include the following.

(* Represents the binding site with Y.)

Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y11), formulas (Y36) to formula (Y38), and formulas (Y39) to formula (Y40). Be done.
When -CH _2- contained in the alicyclic hydrocarbon group represented by Y is replaced by -O-, -S (O) _2- or -CO-, the number may be one or two or more. good. Examples of such a group include groups represented by the formulas (Y12) to (Y35).

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（Ｙ３０）、式（Ｙ３１）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（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（Ｙ３０）、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、酸素原子を含むスピロ環である場合には、２つの酸素原子間のアルカンジイル基は、１以上のフッ素原子を有することが好ましい。また、ケタール構造に含まれるアルカンジイル基のうち、酸素原子に隣接するメチレン基には、フッ素原子が置換されていないのが好ましい。

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

As the substituent of the methyl group represented by Y, 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 or-( CH ₂ ) _ja -O-CO-R ^b1 group (in the formula, R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic group having 6 to 18 carbon atoms. Represents a hydrocarbon group. Ja represents an integer of 0 to 4) and the like.
The substituent of the alicyclic hydrocarbon group represented by Y includes an alkyl group having 1 to 12 carbon atoms and an alicyclic group having 3 to 16 carbon atoms which may be substituted with a halogen atom, a hydroxy group or a hydroxy group. Hydrocarbon groups, alkoxy groups with 1 to 12 carbon atoms, aromatic hydrocarbon groups with 6 to 18 carbon atoms, aralkyl groups with 7 to 21 carbon atoms, alkylcarbonyl groups with 2 to 4 carbon atoms, glycidyloxy groups or-( CH ₂ ) _ja -O-CO-R ^b1 group (in the formula, R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic group having 6 to 18 carbon atoms. Represents a hydrocarbon group. Ja represents an integer of 0 to 4. An alkyl group having 1 to 16 carbon atoms and an alicyclic hydrocarbon group having 3 to 16 carbon atoms have _—CH2 −. , -O-, -S (O) ₂ -or-CO- may be replaced.) And the like.

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 cycloheptyl group, a cyclooctyl group, a norbornyl group, an adamantyl group and the like.
The alicyclic hydrocarbon group may have a chain hydrocarbon group, and examples thereof include a methylcyclohexyl group and a dimethylcyclohexyl group.
Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group and a phenanthryl group.
The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and may have an aromatic hydrocarbon group having 1 to 18 carbon atoms (trill group). , Xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2-methyl-6-ethylphenyl group, etc.), and alicyclic hydrocarbon group having 3 to 18 carbon atoms. It preferably has an aromatic hydrocarbon group (p-adamantylphenyl group, p-cyclohexylphenyl group, etc.).
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group and a nonyl group. Examples include a group, a decyl group, an undecyl group, a dodecyl group and the like.
Examples of the alkyl group substituted with the hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group.
Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group and a naphthylethyl group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group and the like.

Examples of Y include the following.

When Y is a methyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, -CH _2- adjacent to Y in L ^b1 is -O-. Alternatively, it is preferably replaced with -CO-.

Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably an adamantane group which may have a substituent, and is said to be an alicyclic hydrocarbon. -CH _2- , which constitutes a hydrogen group or an 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 by the following.

Examples of the anion in the salt represented by the formula (B1) include anions represented by the formulas (B1-A-1) to (B1-A-54) [hereinafter, "anion (B1-A)" according to the formula number. -1) ”and so on. ] Are preferable, and the formulas (B1-A-1) to (B1-A-4), formulas (B1-A-9), formulas (B1-A-10), and formulas (B1-A-24) to formulas (B1-A-24) to formulas are preferable. (B1-A-33), formula (B1-A-36) to formula (B1-A-40), formula (B1-A-47) to formula (B1-A-54). Anions are more preferred.

ここでＲ^ｉ２～Ｒ^ｉ７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。Ｒ^ｉ８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. Group, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. ^LA41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Q ^b1 and Q ^b2 have the same meanings as described above.
Specific examples of the anion in the salt represented by the formula (B1) include the anion described in JP-A-2010-204646.

Preferred examples of the anion in the salt represented by the formula (B1) include anions represented by the formulas (B1a-1) to (B1a-30).

Among them, the formulas (B1a-1) to (B1a-3) and the formulas (B1a-7) to (B1a-16), the formulas (B1a-18), the formulas (B1a-19), and the formulas (B1a-22). )-Anion represented by any of the formulas (B1a-30) is preferable.

Examples of Z1 ⁺ in the formula (B1) include those similar to the cation in the salt (I).

The acid generator (B1) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. The acid generator (B1) is preferably an anion represented by any of the formulas (B1a-1) to (B1a-3) and the formulas (B1a-7) to (B1a-16), and a cation ( Examples include a combination with b2-1) or a cation (b2-3).

Examples of the acid generator (B1) include organic sulfonic acid-organic sulfonium salt, and examples thereof include Acid Generation described in JP2013-68914A, JP2013-3155, and JP2013-11905. Agents and the like can be mentioned. Specifically, those represented by any of the formulas (B1-1) to (B1-48) can be mentioned. Examples of the acid generator (B) include formulas (B1-1) to (B1-3), formulas (B1-5) to formulas (B1-7), and formulas (B1-11) to formulas (B1-14). , Formula (B1-17), formula (B1-20) to formula (B1-26), formula (B1-29), formula (B1-31) to formula (B1-48). Is particularly preferred.

[Resist composition]
The resist composition of the present invention contains a resin having an acid unstable group (hereinafter, may be referred to as "resin (A)") and the above-mentioned acid generator containing a salt (I). Here, the "acid-unstable group" is a structural unit having a leaving group, the leaving group being removed by contact with an acid, and the constituent unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). Means the group that converts to.
The resist composition further preferably contains a quencher (hereinafter, may be referred to as “quencher (C)”) and preferably contains a solvent (hereinafter, may be referred to as “solvent (E)”). ..

<Acid generator>
In the resist composition of the present invention, the content of the salt (I) is preferably 1 to 20% by mass, more preferably 2 to 15% by mass, based on the resin (A).
The acid generator (B) may contain one kind alone or two or more kinds.
The content of the acid generator (B) is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, based on the resin (A).

<Resin (A)>
The resin (A) has a structural unit having an acid unstable group (hereinafter, may be referred to as “structural unit (a1)”). The resin (A) preferably further contains a structural unit other than the structural unit (a1). As the structural unit other than the structural unit (a1), a structural unit having no halogen atom and no acid unstable group (hereinafter, may be referred to as “structural unit (s)”), a structural unit (a1), and a structural unit (a1). A structural unit other than the structural unit (s) (for example, a structural unit having a halogen atom (a4), a structural unit having a non-desorbed hydrocarbon group (a5), a structural unit having a carboxy group (a6), and decomposition by exposure. Examples thereof include structural units (II) that generate acid and other structural units derived from monomers known in the art.

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

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

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

[In the 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. Represented, R ^a2'and R ^a3' are bonded to each other to form a divalent heterocyclic group having 3 to 20 carbon atoms together with the carbon atom and X to which they are bonded, and the hydrocarbon group and the divalent complex are formed. -CH _2- contained in the ring group may be replaced with -O- or -S-.
X represents an oxygen atom or a sulfur atom.
na'represents 0 or 1.
* Represents a bond. ]

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

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

Examples of the group in which the alkyl group and the alicyclic hydrocarbon group are combined include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group and a norbornyl group. Examples thereof include an ethyl group.
Preferably, ma is 0 and na is 1.
Examples of -C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R a ² are bonded to each other to form a divalent alicyclic hydrocarbon group include the following groups. The divalent alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

Ｒ^a1'及びＲ^a2'のうち、少なくとも１つは水素原子であることが好ましい。
ｎａ’は、好ましくは０である。 Examples of the hydrocarbon group of R a1'to R ^{a3' include} an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same as above.
Examples of the aromatic hydrocarbon group 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 and biphenyl. Examples thereof include an aryl group such as a group, a phenanthryl group, a 2,6-diethylphenyl group and a 2-methyl-6-ethylphenyl group.
Examples of the combined group include a group combining the above-mentioned alkyl group and an alicyclic hydrocarbon group, an aralkyl group such as a benzyl group, and an aryl-cyclohexyl group such as a phenylcyclohexyl group.
Examples of the divalent heterocyclic group formed by R ^a2'and R ^a3'bonding to each other together with the carbon atom and X to which they are bonded include the following groups. * Represents a bond.

Of R ^a1'and R ^a2' , at least one is preferably a hydrogen atom.
na'is preferably 0.

As the group represented by the formula (1), a 1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^a1 to R ^a3 are alkyl groups, ma = 0, na = 1, preferably tert-butoxycarbonyl). Group), 2-alkyl adamantan-2-yloxycarbonyl group (in formula (1), R ^a1 , R ^a2 and the carbon atom to which they are bonded are adamantyl groups, R ^a3 is an alkyl group, ma = 0, na = 1 ) And 1- (adamantan-1-yl) -1-alkylalkoxycarbonyl group (in formula (1), R ^a1 and R ^a2 are alkyl groups, R ^a3 is adamantyl group, ma = 0, na = 1), etc. Specifically, the following groups can be mentioned. * Represents a bond.

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

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

Among the (meth) acrylic monomers having an acid unstable group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. 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－との結合手を表す。
Ｒ^a01、Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a02、Ｒ^a03及びＲ^a04は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組み合わせた基を表す。
Ｒ^ａ６及びＲ^ａ７は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組合せることにより形成される基を表す。
ｍ１は０～１４のいずれかの整数を表す。
ｎ１は０～１０のいずれかの整数を表す。
ｎ１’は０～３のいずれかの整数を表す。］ The structural unit derived from the (meth) acrylic monomer having a group represented by the formula (1) is preferably a structural unit represented by the formula (a1-0) (hereinafter referred to as a structural unit (a1-0)). In some cases), a structural unit represented by the formula (a1-1) (hereinafter, may be referred to as a structural unit (a1-1)) or a structural unit represented by the formula (a1-2) (hereinafter, referred to as a structural unit). It may be referred to as a structural unit (a1-2)). These may be used alone or in combination of two or more.

[In the formula (a1-0), the formula (a1-1) and the formula (a1-2),
^La01 , ^La1 and ^La2 independently represent -O- or ^* -O- (CH ₂ ) _k1 -CO-O-, k1 represents an integer of 1 to 7, and * represents an integer of 1 to 7. -Represents a bond with CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these groups.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining them.
m1 represents any integer from 0 to 14.
n1 represents any integer from 0 to 10.
n1'represents an integer of 0 to 3. ]

R ^a01 , R ^a4 and R ^a5 are preferably methyl groups.
^La01 , La1 and ^La2 are preferably oxygen atoms or * -O- (CH ₂ ) _k01 -CO-O- (where ^k01 is preferably an integer of 1 to 4, more preferably. Is 1), more preferably an oxygen atom.
The alkyl groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 , the alicyclic hydrocarbon group and the group combining these are the same as the groups mentioned in R ^a1 to R ^a3 of the formula (1). The group is mentioned.
The alkyl group of R ^a02 , R ^a03 and R ^a04 preferably has 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.
The alicyclic hydrocarbon groups of R ^a02 , R ^a03 and R ^a04 have preferably 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms.
The group in which the alkyl group and the alicyclic hydrocarbon group are combined preferably has a total carbon number of 18 or less in combination of these alkyl groups and the alicyclic hydrocarbon group.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, and 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, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.
The number of carbon atoms of 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 further preferably an ethyl group or an isopropyl group.
m1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1'is preferably 0 or 1.

As the structural unit (a1-0), for example, a structural unit represented by any one of the formulas (a1-0-1) to (a1-0-12) and a methyl group corresponding to R ^a01 are used as hydrogen atoms. Examples thereof include the replaced structural units, and structural units represented by any of the formulas (a1-0-1) to (a1-0-10) are preferable.

Examples of the monomer for deriving the structural unit (a1-1) include the monomers described in JP-A-2010-204646. Among them, the structural unit represented by any of the formulas (a1-1-1) to ( ^a1-1-4 ) and the structural unit in which the methyl group corresponding to Ra4 is replaced with a hydrogen atom are preferable, and the formula (a1) is preferable. The structural unit represented by any of 1-1) to (a1-1-4) is more preferable.

As the structural unit (a1-2), the structural unit represented by any of the formulas (a1-2-1) to ( ^a1-2-6 ) and the methyl group corresponding to Ra5 were replaced with hydrogen atoms. Structural units are mentioned, and the formula (a1-2-2), the formula (a1-2-5) and the formula (a1-2-6) are preferable.

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%, and more preferably 20 to 85 mol% with respect to the unit.

［式（ａ１－４）中、
Ｒ^a32は、水素原子、ハロゲン原子、又は、ハロゲン原子を有してもよい炭素数１～６のアルキル基を表す。
Ｒ^a33は、ハロゲン原子、ヒドロキシ基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数２～４のア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。］ As the structural unit (a1) having a group represented by the group (2), the structural unit represented by the formula (a1-4) (hereinafter, may be referred to as “structural unit (a1-4)”). Can be mentioned.

[In equation (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, and acryloyl. Represents an oxy group or a methacryloyloxy group.
la represents an integer of 0 to 4. When la is 2 or more, a plurality of Ra ^33s may be the same or different from each other.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^a35 and R ^a36 are bonded to each other. Then, together with CO to which they are bonded, a divalent hydrocarbon group having 2 to 20 carbon atoms is formed, and -CH _2- contained in the hydrocarbon group and the divalent hydrocarbon group is -O-. Alternatively, it may be replaced with —S—. ]

Examples of the alkyl group of R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group and the like. 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 of 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 a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, and 1,1,. 2,2-Tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 4,4-Octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl group, n -Perfluorohexyl group and the like can be mentioned.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group and the like. Of these, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is even more preferable.
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 R ^a34 and R ^a35 include the same groups as R a1'and R ^{a2' in} the formula (2).
Examples of R ^a36 include an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining them. Be done.

In the formula (a1-4), a hydrogen atom is preferable as R ^a32 .
As R ^a33 , an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group and an ethoxy group are more preferable, and a methoxy group is further preferable.
As la, 0 or 1 is preferable, and 0 is more preferable.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrocarbon group having 1 to 12 carbon atoms, and 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. It is a group to be formed, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and the alicyclic hydrocarbon group in R ^a36 are preferably unsubstituted. When the aromatic hydrocarbon group in R ^a36 has a substituent, the aryloxy group having 6 to 10 carbon atoms is preferable as the substituent.

Examples of the monomer for deriving the structural unit (a1-4) include the monomers described in JP-A-2010-204646, preferably formulas (a1-4-1) to (a1-4-7). ), And more preferably, the monomers represented by the formulas (a1-4-1) to (a1-4-5) are mentioned.

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

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

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

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

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

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

Moreover, the following structural unit is also mentioned as a structural unit (a1).

When the resin (A) contains the above structural units, the content thereof is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, and 20 to 85 mol% with respect to all the structural units of the resin (A). % Is more preferable.

<Structural unit (s)>
The structural unit (s) is derived from a monomer having no halogen atom and no acid unstable group (hereinafter, may be referred to as “monomer (s)”). As the monomer for deriving the structural unit (s), a monomer having no acid unstable group known in the resist field can be used.
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid unstable group is preferable. A structure having a hydroxy group and no acid unstable group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structure having a lactone ring and no acid unstable group. If a resin having a unit (hereinafter sometimes referred to as "structural unit (a3)") is used in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

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

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

[In formula (a2-A),
R ^a50 represents an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, and acryloyl. Represents an oxy group or a methacryloyloxy group.
A ^a50 represents a single bond or ^* -X ^a51- (A ^a52- X ^a52 ) _na- , and * represents a bond with a carbon atom to which -R ^a50 is bonded.
A ^a52 independently represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 independently represent —O—, —CO—O— or —O—CO—, respectively.
na represents 0 or 1.
mb represents any integer from 0 to 4. When mb is an integer of 2 or more, the plurality of Ra ^51s may be the same or different from each other. ]

Examples of the halogen atom in R ^a50 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 in ^Ra50 include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group and 1 , 1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3 , 3,4,4-Octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl Examples include groups and n-perfluorohexyl groups.
R ^a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.
Examples of the alkyl group of R ^a51 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group and an n-hexyl group.
Examples of the alkoxy group of R ^a51 include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group and a tert-butoxy group. An alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further preferable.
Examples of the alkylcarbonyl group in ^Ra51 include an acetyl group, a propionyl group, a butyryl group and the like.
Examples of the alkylcarbonyloxy group in ^Ra51 include an acetyloxy group, a propionyloxy group and a butyryloxy group.
R ^a51 is preferably a methyl group.

^* -X ^a51- (A ^a52- X ^a52 ) _na -is ^* -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 -, Can be mentioned. Of these, ^* -CO-O-, ^* -CO-O-A ^a52 -CO-O- or ^* -O-A ^a52 -CO-O- are preferable.

The alkanediyl group includes a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-. 1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2 -Methylbutane-1,4-diyl group and the like can be mentioned.
A ^a52 is preferably a methylene group or an ethylene group.

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

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

The structural unit (a2-A) includes a structural unit represented by the formulas (a2-2-1) to (a2--2-4) and a structural unit in which a methyl group corresponding to ^Ra50 is replaced with a hydrogen atom. Can be mentioned. The structural unit (a2-A) is a hydrogen atom having a structural unit represented by the formula (a2-2-1), a structural unit represented by the formula (a2--2-3), and a methyl group corresponding to ^Ra50 . It is preferably a replaced structural unit.

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

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

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

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

In the formula (a2-1), ^La3 is preferably -O-, -O- (CH ₂ ) _f1 -CO-O- (the f1 is an integer of 1 to 4). , More preferably -O-.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

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

When the resin (A) contains the structural unit (a2-1), the content thereof is usually 1 to 45 mol%, preferably 1 to 40 mol%, based on all the structural units of the resin (A). It is more preferably 1 to 35 mol%, further preferably 2 to 20 mol%, and even more preferably 2 to 10 mol%.

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocyclic ring such as β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a fused ring of a monocyclic lactone ring and another ring. But it may be. Preferably, a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure can be mentioned.

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

[In the formula (a3-1), the formula (a3-2), the formula (a3-3) and the formula (a3-4),
L ^a4 , ^La 5 and ^{La 6} represent a group represented by -O- or ^* -O- (CH ₂ ) _k3 -CO-O- (k3 represents an integer of 1 to 7). ..
L ^a7 is -O-, ^* -OL ^a8 -O-, ^{* -OL a8-CO-O-, * -OL a8 -} CO-O-L ^a9 -CO-O- or ^* -O-L ^a8 -O-CO-L ^a9 -O-represented.
L ^a8 and ^{La 9} each independently represent an alkanediyl group having 1 to 6 carbon atoms.
* Represents a bond with a carbonyl group.
R ^a18 , R ^a19 and R ^a20 represent a hydrogen atom or a methyl group.
R ^a24 represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom or a halogen atom which may have a halogen atom.
Ra ²¹ represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
R ^a22 , R ^a23 and R ^a25 represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5.
q1 represents an integer of 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, the plurality of R ^a21 , R ^a22 , R ^a23 and / or R ^a25 may be the same or different from each other. ]

Examples of the aliphatic hydrocarbon group of R ^a21 , R ^a22 , R ^a23 and R ^a25 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group and a tert-butyl group. Alkyl groups can be mentioned.
Examples of the halogen atom of ^Ra24 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkyl group of R ^a24 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group and an n-hexyl group. An alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.
Alkyl groups having a halogen atom of ^Ra24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and perfluoro. Examples thereof include a hexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.

The alkanediyl groups of ^La8 and ^La9 include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group and pentane-1,5. -Diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, Examples thereof include a 4-diyl group and a 2-methylbutane-1,4-diyl group.

In the formulas (a3-1) to (a3-3), ^La4 to ^La6 are independent of each other, preferably −O— or k3 is an integer of any one of 1 to 4 * —O— (. CH ₂ ) A group represented by _k3 -CO-O-, more preferably -O- and * -O-CH ₂ -CO-O-, still 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 independently, preferably an integer of 0 to 2, and more preferably 0 or 1.

（式中、Ｒ^ａ２４、Ｌ^ａ７は、上記と同じ意味を表す。） In the formula (a3-4), ^Ra24 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 further preferably a hydrogen atom or a methyl group. Is.
^Ra25 is preferably a carboxy group, a cyano group or a methyl group.
L ^a7 is preferably -O- or ^* -OL ^a8 -CO-O-, and more preferably -O-, -O-CH ₂ -CO-O- or -O-C ₂ H _4- . It is CO-O-.
In particular, the formula (a3-4) is preferably the formula (a3-4)'.

(In the formula, ^Ra24 and ^La7 have the same meanings as above.)

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

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 all the structural units of the resin (A). , More preferably 10-60 mol%.
Further, the contents of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3) and the structural unit (a3-4) are the respective contents with respect to all the structural units of the resin (A). 5 to 60 mol% is preferable, 5 to 50 mol% is more preferable, and 10 to 50 mol% is further preferable.

［式（ａ４－０）中、
Ｒ⁵⁶は、水素原子又はメチル基を表す。
Ｌ⁴は、単結合又は炭素数１～４の脂肪族飽和炭化水素基を表す。
Ｌ³は、炭素数１～８のペルフルオロアルカンジイル基又は炭素数３～１２のペルフルオロシクロアルカンジイル基を表す。
Ｒ⁶は、水素原子又はフッ素原子を表す。］ <Structural unit (a4)>
Examples of the structural unit (a4) include a structural unit represented by the formula (a4-0).

[In equation (a4-0),
R ⁵⁶ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ 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 aliphatic saturated hydrocarbon group of L ⁴ include a linear alkanediyl group such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, and an ethane-1,1-. Branched alkanediyl groups such as diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group. The group is mentioned.

The perfluoroalkanediyl group of L ³ includes a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, and a perfluoropropane. -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 Examples thereof include -2,2-diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like.
Examples of the perfluorocycloalkanediyl group of L ³ include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantandiyl group and the like.

L ⁴ is preferably a single bond, a methylene group or an ethylene group, and more preferably a single bond or a methylene group.
L ³ is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

Examples of the structural unit (a4-0) include the structural unit shown below and the structural unit in which the methyl group corresponding to ^R55 in the following structural unit is replaced with a hydrogen atom.

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

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

[In equation (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH _2- contained in the hydrocarbon group may be replaced with -O- or -CO-. good.
A ^a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by the formula (ag1). However, at least one of ^Aa41 and ^Ra42 has a fluorine atom as a substituent.

[In the formula (ag1),
s represents 0 or 1.
A a ⁴² and A a ⁴⁴ each independently represent a saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a saturated hydrocarbon group having 1 to 5 carbon atoms which may have a single bond or a substituent.
X ^a41 and X ^a42 independently represent -O-, -CO-, -CO-O- or -O-CO-, respectively.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 7 or less. ]
* Is a bond, and * on the right is a bond with -O-CO-R ^a42 . ]

Examples of the hydrocarbon group of R ^a42 include chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these groups.
The chain and cyclic aliphatic hydrocarbon groups may have a carbon-carbon unsaturated bond, but chain and cyclic aliphatic saturated hydrocarbon groups are preferable. The aliphatic saturated hydrocarbon group is a fat formed by combining a linear or branched alkyl group and a monocyclic or polycyclic alicyclic hydrocarbon group, and an alkyl group and an alicyclic hydrocarbon group. Examples include group hydrocarbon groups.

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

Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a biphenylyl group, a phenanthryl group and a fluorenyl group.

［式（ａ－ｇ３）中、
Ｘ^a43は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^a45は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
＊は結合手を表す。］
ただし、Ｒ^a42－Ｘ^a43－Ａ^a45において、Ｒ^a42がハロゲン原子を有しない場合は、Ａ^a45は、少なくとも１つのハロゲン原子を有する炭素数１～１７の脂肪族炭化水素基を表す。 R ^a42 may have a halogen atom and a group represented by the formula (ag3) as a substituent. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.

[In the formula (ag3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
* Represents a bond. ]
However, in R ^a42- X ^a43 -A ^a45 , when R ^a42 does not have a halogen atom, A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms having at least one halogen atom.

Examples of the aliphatic hydrocarbon group of A ^a45 include the same groups as those exemplified in R ^a42 .
R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, and more preferably an alkyl group having a halogen atom and / or an aliphatic hydrocarbon group having a group represented by the formula (ag3). preferable.
When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and further preferably having a carbon number of carbons. It is a perfluoroalkyl group of 1 to 6, and 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 an aliphatic hydrocarbon group having a group represented by the formula (ag3), the aliphatic hydrocarbon includes the number of carbon atoms contained in the group represented by the formula (ag3). The total carbon number of the group is preferably 15 or less, more preferably 12 or less. When the group represented by the formula (ag3) is used as a substituent, the number thereof is preferably one.

［式（ａ－ｇ２）中、
Ａ^a46は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
Ｘ^a44は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
ただし、Ａ^a46、Ａ^a47及びＸ^a44の炭素数の合計は１８以下であり、Ａ^a46及びＡ^a47のうち、少なくとも一方は、少なくとも１つのハロゲン原子を有する。
＊はカルボニル基との結合手を表す。］ Aliphatic hydrocarbons having a group represented by the formula (ag3) are more preferably a group represented by the formula (ag2).

[In the formula (ag2),
A ^a46 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents a carbonyloxy group or an oxycarbonyl group.
A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47 and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* Represents a bond with a carbonyl group. ]

The 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 further preferably A ^a47 having a cyclohexyl group or an adamantyl group.

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

The alkanediyl group of A ^a41 is a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a 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, etc. Examples thereof include a branched alkanediyl group such as 2-methylbutane-1,4-diyl group.
Examples of the substituent in the alkanediyl group of A ^a41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and further preferably an ethylene group.

The saturated hydrocarbon groups of A ^a42 , A ^a43 and A ^a44 in the group represented by the formula (a-g1) are preferably chain-type and cyclic-type saturated hydrocarbon groups and groups formed by combining them. .. The saturated hydrocarbon group is a saturated hydrocarbon formed by combining a linear or branched alkanediyl group and a monocyclic alicyclic hydrocarbon group, and an alkanediyl group and an alicyclic hydrocarbon group. The group etc. can be mentioned. Specifically, a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, Examples thereof include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
Examples of the substituent of the saturated hydrocarbon group of A ^a42 , A ^a43 and A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
s is preferably 0.

Examples of the group represented by the formula (ag1) in which X ^a42 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group include the following groups. In the following examples, * and ** represent the bond, respectively, and ** is the bond with -O-CO-R ^a42 .

Examples of the structural unit represented by the formula (a4-1) include the structural unit shown below and the structural unit in which the methyl group corresponding to ^Ra41 in the following structural unit is replaced with a hydrogen atom.

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

[In equation (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 represents-(CH ₂ ) _j1 -,-(CH ₂ ) _j2 -O- (CH ₂ ) _{j3- or-} (CH ₂ ) _j4 -CO-O- (CH ₂ ) _j5- .
j1 to j5 each independently represent an integer of 1 to 6.
R ^f22 represents a hydrocarbon group having a fluorine atom and having 1 to 10 carbon atoms. ]

Hydrocarbon groups of R ^f22 include chain, cyclic and aliphatic hydrocarbon groups formed by combining them. As the aliphatic hydrocarbon group, an alkyl group and an alicyclic hydrocarbon group are preferable.
Examples of the hydrocarbon group having a fluorine atom include an alkyl group having a fluorine atom, an alicyclic hydrocarbon group having a fluorine atom, and the like.
Specifically, examples of the alkyl group having a fluorine atom include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, and a 2,2,2-trifluoroethyl group. Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2 , 2,2-Tetrafluoroethyl group, Perfluoropropyl group, 1,1,2,2-Tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2, 2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2,2,3,3 , 4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group and perfluorohexyl Fluoroalkyl groups such as groups can be mentioned.
Examples of the alicyclic hydrocarbon group having a fluorine atom include a fluorocycloalkyl group such as a perfluorocyclohexyl group and a perfluoroadamantyl group.
R ^f22 is preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, and 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 having a fluorine atom is more preferable.

In the formula (a4-4), as A ^f21 , − (CH ₂ ) _j1 − is preferable, an ethylene group or a methylene group is more preferable, and a methylene group is further preferable.

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

When the resin (A) has a structural unit (a4), the content thereof is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and 3) with respect to all the structural units of the resin (A). -10 mol% is more preferred.

［式（ａ５－１）中、
Ｒ⁵¹は、水素原子又はメチル基を表す。
Ｒ⁵²は、炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる水素原子は炭素数１～８の脂肪族炭化水素基で置換されていてもよい。但し、Ｌ⁵⁵との結合位置にある炭素原子に結合する水素原子は、炭素数１～８の脂肪族炭化水素基で置換されない。
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メチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］ <Structural unit (a5)>
Examples of the non-eliminating hydrocarbon group of the structural unit (a5) include a group having a linear, branched or cyclic hydrocarbon group. Among them, the structural unit (a5) preferably contains an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1).

[In equation (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. .. However, the hydrogen atom bonded to the carbon atom at the bond position with L ⁵⁵ is not substituted with the aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

The alicyclic hydrocarbon group of R ⁵² may be either a monocyclic or polycyclic group. 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.
The aliphatic hydrocarbon group having 1 to 8 carbon atoms includes, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, and the like. Alkyl groups such as octyl group and 2-ethylhexyl group can be mentioned.
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, and more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

Examples of the divalent saturated hydrocarbon group of L ⁵⁵ include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and a divalent aliphatic saturated hydrocarbon group is preferable. ..
Examples of the divalent aliphatic saturated hydrocarbon group include an alkanediyl group such as a methylene group, an ethylene group, a propanediyl group, a butanjiyl group and a pentandiyl group.
The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include a cycloalkanediyl group such as a cyclopentanediyl group and a cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantandiyl group and a norbornanediyl group.

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

In equation (L1-1),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total number of carbon atoms of L ^x 1 and L ^{x 2} is 16 or less.
In equation (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 number of carbon atoms of L ^x3 and L ^x4 is 17 or less.
In formula (L1-3),
L ^{x 5} 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 ^x 1 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, and 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, and 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 ^{x 5} is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and 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, and 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, and 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, and 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, and more preferably a cyclohexanediyl group or an adamantanediyl group.

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

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

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

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

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

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

When the resin (A) has a structural unit (a5), the content thereof is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and 3) with respect to all the structural units of the resin (A). It is more preferably ~ 15 mol%.

<Structural unit (a6)>
Examples of the structural unit (a6) having a carboxy group include structural units represented by the following.

When the resin (A) has the structural unit (a6), the content thereof is preferably 1 to 40 mol%, more preferably 2 to 35 mol%, and 3) with respect to all the structural units of the resin (A). ~ 30 mol% is more preferable.

<Structural unit (II)>
Specific examples of the structural unit (II) that decomposes by exposure to generate an acid include the structural units described in JP-A-2016-79235, and the side chains include a sulfonate group or a carboxylate group and an organic cation. It is preferable that the structural unit has a sulfonio group and an organic anion in the side chain.

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

[In the formula (II-2-A'),
X ^III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O-, -S- or -CO-. 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 have 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 an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom.
Z ^{a +} represents an organic cation. ]

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

Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X ^III3 include a linear or branched alkanediyl group and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. And may be a combination of these.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-Diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonan-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group and other linear alkanediyl groups; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group , Pentan-1,4-diyl group, 2-methylbutane-1,4-diyl group and other branched alkanediyl groups; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1 , 4-Diyl group, cyclooctane-1,5-Diyl group and other cycloalkandyl groups; norbornan-1,4-diyl group, norbornan-2,5-diyl group, adamantan-1,5-diyl group, adamantan Examples thereof include a divalent polycyclic alicyclic saturated hydrocarbon group such as -2,6-diyl group.

When -CH _2- contained in the saturated hydrocarbon group is replaced with -O-, -S- or -CO-, for example, a divalent group represented by the formulas (X1) to (X53) is used. Can be mentioned. However, the number of carbon atoms before that -CH _2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- is 17 or less, respectively. In the following equation, * represents a bond with A ^x1 .

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

Examples of the organic cation represented by Z ^{a +} include organic onium cations such as organic sulfonium cations, organic iodine cations, organic ammonium cations, organic benzothiazolium cations and organic phosphonium cations, and organic sulfonium cations and organic iodine cations. Is preferred, and aryl sulfonium cations are more preferred.
Specific examples thereof include the same as those exemplified for the organic cations in the salt (I).

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

[In the formula (II-2-A), R ^III3 , X ^III3 and Za ⁺ have the same meanings as described above.
Z represents an integer of 0 to 6.
R ^III2 and R ^III4 independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms, and when z is 2 or more, a plurality of R ^III2 and R ^III4 are identical to each other. It may or may not be different.
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 , ^Qa and ^Qb include the same perfluoroalkyl group having 1 to 6 carbon atoms represented by ^Q1 .

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

[In the formula (II-2-A-1),
R ^III2 , R ^III3 , R ^III4 , Q ^a , Q ^b , z and Z ^{a +} have the same meanings as described above.
R ^III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
X ² represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O-, -S- or -CO-. Often, the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a halogen atom or a hydroxy group. ]

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

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

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

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

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

Examples of the structural unit containing a cation in the formula (II-1-1) include structural units represented by the following.

Examples of the organic anion represented by A ⁻ include a sulfonic acid anion, a sulfonylimide anion, a sulfonylmethide anion, a carboxylic acid anion and the like. The organic anion represented by A ⁻ is preferably a sulfonic acid anion, and more preferably an anion contained in the above-mentioned acid generator (B1).

Examples of the sulfonylimide anion represented by A ⁻ include the following.

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

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

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

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 (for example, radical polymerization method) using a monomer for inducing these structural units. can do. The content of each structural unit of the resin (A) can be adjusted by adjusting the amount of the monomer used for the polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, still more preferable). Is 15,000 or less). In the present specification, the weight average molecular weight is a value obtained by gel permeation chromatography under the conditions described in Examples.

<Resin (X) other than resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A). Examples of such a resin include a resin containing a structural unit (a4) (hereinafter, may be referred to as “resin (X)”).
Examples of the structural unit that the resin (X) may further include include a structural unit (a1), a structural unit (a2), a structural unit (a3), a structural unit (a5), and other known structural units.
The resin (X) is more preferably a resin composed of the structural unit (a4) and / or the structural unit (a5).
When the resin (X) contains the structural unit (a4), the content thereof is preferably 40 mol% or more, more preferably 45 mol% or more, and 50 mol% or more with respect to all the structural units of the resin (X). Is even more preferable.
When the resin (X) contains the structural unit (a5), the content thereof is preferably 10 to 60 mol%, more preferably 20 to 55 mol%, and 25 to 25 to all the structural units of the resin (X). 50 mol% is more preferred.

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

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

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

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

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

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

Specifically, 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-,3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine, hexylamine. , Heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, trypentylamine, trihexylamine, Triheptylamine, Trioctylamine, Trinonylamine, Tridecylamine, Methyldibutylamine, Methyldipentylamine, Methyldihexylamine, Methyldicyclohexylamine, Methyldiheptylamine, Methyldioctylamine, Methyldinonylamine, Methyldidecylamine , Ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, Triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino- 3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di (2-pyridyl) ethane, 1,2-di (4) -Pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethen, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyl) Oxy) ethane, di (2-pyridyl) ketone, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicorylamine, bipyridine and the like. , Preferably diisopropylaniline, and particularly preferably 2,6-diisopropylaniline.

Examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, and 3- (trifluoromethyl) phenyltrimethyl. Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like can be mentioned.

<Salt that produces acid with weak acidity>
The acidity of a salt that produces an acid that is weaker than the acid generated by the acid generator is indicated by the acid dissociation constant (pKa). The salt that generates an acid having a weaker acidity than the acid generated from the acid generator is a salt in which the pKa of the acid generated from the salt is usually -3 <pKa, preferably -1 <pKa <7. It is more preferably a salt of 0 <pKa <5. Examples of the salt that generates an acid weaker than the acid generated from the acid generator include a salt represented by the following formula, a weak acid intramolecular salt represented by the formula (D) described in JP-A-2015-147926, and a special case. Examples thereof include the salts described in JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-390502 and JP-A-2011-191745.

Examples of the weak acid intramolecular salt represented by the formula (D) include the following salts.

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

<Other ingredients>
If necessary, the resist composition of the present invention may contain a component other than the above-mentioned components (hereinafter, may be referred to as "other component (F)"). The other component (F) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes and the like, can be used.

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

<Manufacturing method of resist pattern>
The method for producing a resist pattern of the present invention is
(1) A step of applying the resist composition of the present invention onto a substrate,
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
It includes (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 by a commonly used device such as a spin coater. Examples of the substrate include an inorganic substrate such as a silicon wafer. The substrate may be washed before the resist composition is applied, or an antireflection film or the like may be formed on the substrate.

By drying the composition after coating, 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 prebaking), or by using a depressurizing device. The heating temperature is preferably 50 to 200 ° C., and the heating time is preferably 10 to 180 seconds. The pressure for drying under reduced pressure is preferably about ¹ to 1.0 × 105 Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. The exposure light source includes a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ excima laser (wavelength 157 nm) that emits laser light in the ultraviolet region, and a solid-state laser light source (YAG or semiconductor laser). Etc.), and various ones such as those that radiate harmonic laser light in the far ultraviolet region or vacuum ultraviolet region by wavelength conversion, those that irradiate electron beams, super-ultraviolet light (EUV), etc. are used. Can be done. In the present specification, irradiating these radiations may be collectively referred to as "exposure". At the time of exposure, the exposure is usually performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, it may be exposed by direct drawing without using a mask.

The composition layer after exposure is heat-treated (so-called post-exposure bake) in order to promote the deprotection reaction at the acid unstable group. 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 and a developer. Examples of the developing method include a dip method, a paddle method, a spray method, and a dynamic dispense method. The development temperature is preferably 5 to 60 ° C., and the development time is preferably 5 to 300 seconds. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any alkaline aqueous solution used in this field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly known as choline) can be mentioned. The alkaline developer may contain a surfactant.
After development, it is preferable to wash the resist pattern with ultrapure water and then remove the substrate and the water remaining on the pattern.

When a negative resist pattern is produced from the resist composition of the present invention, a developer containing an organic solvent (hereinafter, may be referred to as "organic developer") is used as the developer.
Examples of the organic solvent contained in the organic developer include a ketone solvent such as 2-hexanone and 2-heptanone; a glycol ether ester solvent such as propylene glycol monomethyl ether acetate; an ester solvent such as butyl acetate; and a glycol such as propylene glycol monomethyl ether. Examples include an ether solvent; an amide solvent such as N, N-dimethylacetamide; an aromatic hydrocarbon solvent such as anisole, and the like.
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 further preferably substantially only the organic solvent.
Among them, as the organic developer, a developer containing butyl acetate and / or 2-heptanone is preferable. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially butyl acetate and / or 2 -It is more preferable that it is only heptanone.
The organic developer may contain a surfactant. Further, the organic developer may contain a small amount of water.
At the time of development, the development may be stopped by substituting with a solvent of a type different from that of the organic developer.

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

<Use>
The resist composition of the present invention includes 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 electrons. It is suitable as a resist composition for linear (EB) exposure or a resist composition for EUV exposure, and is useful for fine processing of semiconductors.

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

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

式（Ｉ－１－ａ）で表される塩５０．３部及びアセトニトリル２５０部を混合し、その後、４０℃で１時間攪拌した。得られた混合物に、４０℃で、式（Ｉ－１－ｂ）で表される化合物２３．８部を１０分かけて添加し、７０℃に昇温後、７０℃で２時間撹拌することにより、式（Ｉ－１－ｃ）で表される塩を含む溶液を得た。得られた式（Ｉ－１－ｃ）で表される塩を含む溶液を２３℃まで冷却した後、式（Ｉ－１－ｄ）で表される化合物１３部及びアセトニトリル１３部の混合溶液を９０分かけて添加し、２３℃で１時間撹拌することにより、式（Ｉ－１－ｅ）で表される塩を含む溶液を得た。得られた式（Ｉ－１－ｅ）で表される塩を含む溶液に、式（Ｉ－１－ｄ）で表される化合物１３部及び式（Ｉ－１－ｆ）で表される塩０．１部を添加し、２３℃で１８時間攪拌した。得られた反応混合物に、クロロホルム５００部、イオン交換水２００部及び飽和炭酸水素ナトリウム水溶液５０部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水２００部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を２回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル２００部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－１―ｇ）で表される塩４０．３０部を得た。

式（Ｉ－１－ｇ）で表される塩１．８部、式（Ｉ－１－ｈ）で表される化合物０．６部及びクロロホルム１４部を添加した後、２３℃で３０分間攪拌した。得られた混合物に、２３℃で、０．２％カンファースルホン酸のクロロホルム溶液１．４部を添加し、２３℃で１８時間撹拌した。得られた反応溶液に、クロロホルム３０部及びイオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を４回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル１０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－１）で表される塩１．２４部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５４３．２ Example 1: Synthesis of salt represented by formula (I-1)

50.3 parts of the salt represented by the formula (I-1-a) and 250 parts of acetonitrile were mixed, and then the mixture was stirred at 40 ° C. for 1 hour. To the obtained mixture, add 23.8 parts of the compound represented by the formula (I-1-b) at 40 ° C. over 10 minutes, heat the temperature to 70 ° C., and stir at 70 ° C. for 2 hours. To obtain a solution containing a salt represented by the formula (I-1-c). After cooling the obtained solution containing the salt represented by the formula (I-1-c) to 23 ° C., a mixed solution of 13 parts of the compound represented by the formula (I-1-d) and 13 parts of acetonitrile is prepared. The mixture was added over 90 minutes and stirred at 23 ° C. for 1 hour to obtain a solution containing a salt represented by the formula (I-1-e). In the obtained solution containing the salt represented by the formula (I-1-e), 13 parts of the compound represented by the formula (I-1-d) and the salt represented by the formula (I-1-f) are added. 0.1 part was added and the mixture was stirred at 23 ° C. for 18 hours. To the obtained reaction mixture, 500 parts of chloroform, 200 parts of ion-exchanged water and 50 parts of a saturated aqueous sodium hydrogen carbonate solution were added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated. 200 parts of ion-exchanged water was added to the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This washing operation was repeated twice. The recovered organic layer was concentrated, and 200 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 40.30 parts of a salt represented by the formula (I-1-g).

After adding 1.8 parts of the salt represented by the formula (I-1-g), 0.6 parts of the compound represented by the formula (I-1-h) and 14 parts of chloroform, the mixture is stirred at 23 ° C. for 30 minutes. did. To the obtained mixture, 1.4 parts of a chloroform solution of 0.2% camphorsulfonic acid was added at 23 ° C., and the mixture was stirred at 23 ° C. for 18 hours. To the obtained reaction solution, 30 parts of chloroform and 20 parts of ion-exchanged water were added, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. To the recovered organic layer, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This washing operation was repeated 4 times. The recovered organic layer was concentrated, and 10 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 1.24 parts of a salt represented by the formula (I-1).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 543.2

式（Ｉ－１－ｇ）で表される塩１．８部、式（Ｉ－４９－ｆ）で表される化合物０．４部及びクロロホルム１４部を混合した後、２３℃で３０分間攪拌した。得られた混合物に、２３℃で、０．２％カンファースルホン酸のクロロホルム溶液１．４部を添加し、２３℃で１８時間撹拌した。得られた反応溶液に、クロロホルム３０部及びイオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を４回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル１０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－４９）で表される塩０．９９部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５２９．２ Example 2: Synthesis of salt represented by formula (I-49)

After mixing 1.8 parts of the salt represented by the formula (I-1-g), 0.4 parts of the compound represented by the formula (I-49-f) and 14 parts of chloroform, the mixture is stirred at 23 ° C. for 30 minutes. did. To the obtained mixture, 1.4 parts of a chloroform solution of 0.2% camphorsulfonic acid was added at 23 ° C., and the mixture was stirred at 23 ° C. for 18 hours. To the obtained reaction solution, 30 parts of chloroform and 20 parts of ion-exchanged water were added, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. To the recovered organic layer, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This washing operation was repeated 4 times. The recovered organic layer was concentrated, and 10 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 0.99 parts of a salt represented by the formula (I-49).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 529.2

式（Ｉ－１）で表される化合物１．２部、クロロホルム１０部及びメタノール１０部を、反応器に仕込み、２３℃で３０分間攪拌した。得られた混合物に塩酸０．１０部及びイオン交換水１０部を加え、５０℃程度で１時間攪拌した。得られた反応混合物を濃縮した後、得られた濃縮物に、酢酸エチル２５部を添加攪拌後、静置し、分液して有機層を得た。得られた有機層に、１０％炭酸カリウム水溶液５部を加え、２３℃で３０分間攪拌した。その後、静置し、分液して有機層を得た。得られた有機層に、イオン交換水５部を加え、２３℃で３０分間攪拌した。その後、静置し、分液して有機層を得た。このような水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮マスをカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：メタノール／クロロホルム＝１／１）分取することにより、式（Ｉ－２３）で表される化合物０．３１部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ４７１．２ Example 3: Synthesis of salt represented by formula (I-23)

1.2 parts of the compound represented by the formula (I-1), 10 parts of chloroform and 10 parts of methanol were charged in a reactor and stirred at 23 ° C. for 30 minutes. 0.10 parts of hydrochloric acid and 10 parts of ion-exchanged water were added to the obtained mixture, and the mixture was stirred at about 50 ° C. for 1 hour. After concentrating the obtained reaction mixture, 25 parts of ethyl acetate was added to the obtained concentrate, and the mixture was allowed to stand and separated to obtain an organic layer. To the obtained organic layer, 5 parts of a 10% aqueous potassium carbonate solution was added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it was allowed to stand and separated to obtain an organic layer. To the obtained organic layer, 5 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it was allowed to stand and separated to obtain an organic layer. Such a washing operation was repeated 5 times. The obtained organic layer is concentrated, and the concentrated mass is separated by a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: methanol / chloroform = 1/1). 0.31 part of the compound represented by the formula (I-23) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 471.2.

式（Ｉ－９－ａ）で表される塩５．０３部及びアセトニトリル２５部を混合し、その後、４０℃で１時間攪拌した。得られた混合物に、４０℃で、式（Ｉ－９－ｂ）で表される化合物２．３８部を１０分かけて添加し、７０℃に昇温後、７０℃で２時間撹拌することにより、式（Ｉ－９－ｃ）で表される塩を含む溶液を得た。得られた式（Ｉ－９－ｃ）で表される塩を含む溶液を２３℃まで冷却した後、式（Ｉ－９－ｄ）で表される化合物１．０９部及びアセトニトリル１．０９部の混合溶液を１０分かけて添加し、２３℃で１時間撹拌することにより、式（Ｉ－９－ｅ）で表される塩を含む溶液を得た。得られた式（Ｉ－９－ｅ）で表される塩を含む溶液に、式（Ｉ－９－ｄ）で表される化合物１．０９部及び式（Ｉ－９－ｆ）で表される塩０．０１部を添加し、２３℃で１８時間攪拌した。得られた反応混合物に、クロロホルム５０部、イオン交換水２０部及び飽和炭酸水素ナトリウム水溶液５部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を２回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル２０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－９―ｇ）で表される塩１．８８部を得た。

式（Ｉ－９－ｇ）で表される塩１．６７部、式（Ｉ－９－ｈ）で表される化合物０．６部及びクロロホルム１４部を添加した後、２３℃で３０分間攪拌した。得られた混合物に、２３℃で、０．２％カンファースルホン酸のクロロホルム溶液１．４部を添加し、２３℃で１８時間撹拌した。得られた反応溶液に、クロロホルム３０部及びイオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を４回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル１０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－９）で表される塩１．０１部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ４８７．２ Example 4: Synthesis of salt represented by formula (I-9)

5.03 parts of the salt represented by the formula (I-9-a) and 25 parts of acetonitrile were mixed, and then the mixture was stirred at 40 ° C. for 1 hour. To the obtained mixture, 2.38 part of the compound represented by the formula (I-9-b) is added at 40 ° C. over 10 minutes, the temperature is raised to 70 ° C., and the mixture is stirred at 70 ° C. for 2 hours. To obtain a solution containing a salt represented by the formula (I-9-c). After cooling the obtained solution containing the salt represented by the formula (I-9-c) to 23 ° C., 1.09 part of the compound represented by the formula (I-9-d) and 1.09 part of acetonitrile. The mixed solution of the above was added over 10 minutes and stirred at 23 ° C. for 1 hour to obtain a solution containing a salt represented by the formula (I-9-e). In the obtained solution containing the salt represented by the formula (I-9-e), 1.09 parts of the compound represented by the formula (I-9-d) and the compound represented by the formula (I-9-f) are represented. 0.01 part of the salt was added, and the mixture was stirred at 23 ° C. for 18 hours. To the obtained reaction mixture, 50 parts of chloroform, 20 parts of ion-exchanged water and 5 parts of a saturated aqueous sodium hydrogen carbonate solution were added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated. To the recovered organic layer, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This washing operation was repeated twice. The recovered organic layer was concentrated, and 20 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 1.88 parts of a salt represented by the formula (I-9-g).

After adding 1.67 parts of the salt represented by the formula (I-9-g), 0.6 parts of the compound represented by the formula (I-9-h) and 14 parts of chloroform, the mixture is stirred at 23 ° C. for 30 minutes. did. To the obtained mixture, 1.4 parts of a chloroform solution of 0.2% camphorsulfonic acid was added at 23 ° C., and the mixture was stirred at 23 ° C. for 18 hours. To the obtained reaction solution, 30 parts of chloroform and 20 parts of ion-exchanged water were added, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. To the recovered organic layer, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This washing operation was repeated 4 times. The recovered organic layer was concentrated, and 10 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 1.01 part of a salt represented by the formula (I-9).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 487.2

式（Ｉ－３５１－ａ）で表される塩４．８４部及びアセトニトリル３０部を混合し、その後、２３℃で３０分間攪拌した。得られた混合物に、６０℃で、式（Ｉ－３５１－ｂ）で表される化合物２．４１部を１０分かけて添加し、６０℃で２時間撹拌することにより、式（Ｉ－３５１－ｃ）で表される塩を含む溶液を得た。得られた式（Ｉ－３５１－ｃ）で表される塩を含む溶液に、式（Ｉ－３５１－ｄ）で表される化合物１．３２部及びアセトニトリル１．３２部の混合溶液を３０分かけて添加し、６０℃で２時間撹拌することにより、式（Ｉ－３５１－ｅ）で表される塩を含む溶液を得た。得られた式（Ｉ－３５１－ｅ）で表される塩を含む溶液に、式（Ｉ－３５１－ｄ）で表される化合物１．３１部及び式（Ｉ－３５１－ｆ）で表される塩０．０１部を添加し、２３℃で１８時間攪拌した。得られた反応混合物に、クロロホルム５０部、イオン交換水２０部及び飽和炭酸水素ナトリウム水溶液５部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を２回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル２０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－３５１―ｇ）で表される塩３．１６部を得た。

式（Ｉ－３５１－ｇ）で表される塩１．８７部、式（Ｉ－３５１－ｈ）で表される化合物０．６部及びクロロホルム１４部を添加した後、２３℃で３０分間攪拌した。得られた混合物に、２３℃で、０．２％カンファースルホン酸のクロロホルム溶液１．４部を添加し、２３℃で１８時間撹拌した。得られた反応溶液に、クロロホルム３０部及びイオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を４回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル１０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－３５１）で表される塩１．１８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５７３．３ Example 5: Synthesis of salt represented by the formula (I-351)

4.84 parts of the salt represented by the formula (I-351-a) and 30 parts of acetonitrile were mixed, and then the mixture was stirred at 23 ° C. for 30 minutes. To the obtained mixture, 2.41 part of the compound represented by the formula (I-351-b) was added at 60 ° C. over 10 minutes, and the mixture was stirred at 60 ° C. for 2 hours to obtain the formula (I-351). A solution containing the salt represented by −c) was obtained. A mixed solution of 1.32 parts of the compound represented by the formula (I-351-d) and 1.32 parts of acetonitrile is added to the obtained solution containing the salt represented by the formula (I-351-c) for 30 minutes. The mixture was added over and stirred at 60 ° C. for 2 hours to obtain a solution containing a salt represented by the formula (I-351-e). In the obtained solution containing the salt represented by the formula (I-351-e), 1.31 part of the compound represented by the formula (I-351-d) and the formula (I-351-f) are represented. 0.01 part of the salt was added, and the mixture was stirred at 23 ° C. for 18 hours. To the obtained reaction mixture, 50 parts of chloroform, 20 parts of ion-exchanged water and 5 parts of a saturated aqueous sodium hydrogen carbonate solution were added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated. To the recovered organic layer, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This washing operation was repeated twice. The recovered organic layer was concentrated, and 20 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 3.16 parts of a salt represented by the formula (I-351-g).

After adding 1.87 parts of the salt represented by the formula (I-351-g), 0.6 parts of the compound represented by the formula (I-351-h) and 14 parts of chloroform, the mixture is stirred at 23 ° C. for 30 minutes. did. To the obtained mixture, 1.4 parts of a chloroform solution of 0.2% camphorsulfonic acid was added at 23 ° C., and the mixture was stirred at 23 ° C. for 18 hours. To the obtained reaction solution, 30 parts of chloroform and 20 parts of ion-exchanged water were added, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. To the recovered organic layer, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This washing operation was repeated 4 times. The recovered organic layer was concentrated, and 10 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 1.18 parts of a salt represented by the formula (I-351).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 573.3

式（Ｉ－３５３－ａ）で表される塩５．０３部及びアセトニトリル２５部を混合し、その後、４０℃で１時間攪拌した。得られた混合物に、４０℃で、式（Ｉ－３５３－ｂ）で表される化合物２．３８部を１０分かけて添加し、７０℃に昇温後、７０℃で２時間撹拌することにより、式（Ｉ－３５３－ｃ）で表される塩を含む溶液を得た。得られた式（Ｉ－３５３－ｃ）で表される塩を含む溶液を２３℃まで冷却した後、式（Ｉ－３５３－ｄ）で表される化合物１．７０部及びアセトニトリル１．７０部の混合溶液を１０分かけて添加し、２３℃で１時間撹拌することにより、式（Ｉ－３５３－ｅ）で表される塩を含む溶液を得た。得られた式（Ｉ－３５３－ｅ）で表される塩を含む溶液に、式（Ｉ－３５３－ｄ）で表される化合物１．７０部及び式（Ｉ－３５３－ｆ）で表される塩０．０１部を添加し、２３℃で１８時間攪拌した。得られた反応混合物に、クロロホルム５０部、イオン交換水２０部及び飽和炭酸水素ナトリウム水溶液５部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を２回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル２０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－３５３―ｇ）で表される塩３．５２部を得た。

式（Ｉ－３５３－ｇ）で表される塩２．０５部、式（Ｉ－３５３－ｈ）で表される化合物０．６部及びクロロホルム１４部を添加した後、２３℃で３０分間攪拌した。得られた混合物に、２３℃で、０．２％カンファースルホン酸のクロロホルム溶液１．４部を添加し、２３℃で１８時間撹拌した。得られた反応溶液に、クロロホルム３０部及びイオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を４回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル１０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－３５３）で表される塩１．５４部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ６４７．３ Example 6: Synthesis of salt represented by formula (I-353)

5.03 parts of the salt represented by the formula (I-353-a) and 25 parts of acetonitrile were mixed, and then the mixture was stirred at 40 ° C. for 1 hour. To the obtained mixture, 2.38 part of the compound represented by the formula (I-353-b) is added at 40 ° C. over 10 minutes, the temperature is raised to 70 ° C., and the mixture is stirred at 70 ° C. for 2 hours. To obtain a solution containing a salt represented by the formula (I-353-c). After cooling the obtained solution containing the salt represented by the formula (I-353-c) to 23 ° C., 1.70 parts of the compound represented by the formula (I-353-d) and 1.70 parts of acetonitrile are used. The mixed solution of (I-353-e) was added over 10 minutes and stirred at 23 ° C. for 1 hour to obtain a solution containing a salt represented by the formula (I-353-e). In the obtained solution containing the salt represented by the formula (I-353-e), 1.70 parts of the compound represented by the formula (I-353-d) and the compound represented by the formula (I-353-f) are represented. 0.01 part of the salt was added, and the mixture was stirred at 23 ° C. for 18 hours. To the obtained reaction mixture, 50 parts of chloroform, 20 parts of ion-exchanged water and 5 parts of a saturated aqueous sodium hydrogen carbonate solution were added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated. To the recovered organic layer, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This washing operation was repeated twice. The recovered organic layer was concentrated, and 20 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 3.52 parts of a salt represented by the formula (I-353-g).

After adding 2.05 parts of the salt represented by the formula (I-353-g), 0.6 parts of the compound represented by the formula (I-353-h) and 14 parts of chloroform, the mixture is stirred at 23 ° C. for 30 minutes. did. To the obtained mixture, 1.4 parts of a chloroform solution of 0.2% camphorsulfonic acid was added at 23 ° C., and the mixture was stirred at 23 ° C. for 18 hours. To the obtained reaction solution, 30 parts of chloroform and 20 parts of ion-exchanged water were added, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. To the recovered organic layer, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This washing operation was repeated 4 times. The recovered organic layer was concentrated, and 10 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 1.54 parts of a salt represented by the formula (I-353).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 64.3

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

Hereinafter, these monomers will be referred to as "monomer (a1-1-1)" or the like according to the formula number.

Synthesis Example 1 [Synthesis of resin A1]
As the monomers, the monomer (a1-4-2), the monomer (a1-1-3), the monomer (a1-2-6), the monomer (a3-1-1) and the monomer (II-2-A-1-1) ), And its molar ratio [monomer (a1-4-2): monomer (a1-1-3): monomer (a1-2-6): monomer (a3-4-2): monomer (II-2- A-1-1)] is mixed in a ratio of 32:25:35: 5: 3, and further, 1.5 times by mass of methyl with respect to the total mass of all the monomers is added to this monomer mixture. Isobutyl ketone was mixed. Azobisisobutyronitrile as an initiator was added to the obtained mixture so as to be 7 mol% with respect to the total number of moles of all the monomers, and this was polymerized by heating at 85 ° C. for about 5 hours. Was done. Then, a p-toluenesulfonic acid aqueous solution was added to the polymerization reaction solution, and the mixture was stirred for 6 hours and then separated. The recovered organic layer is poured into a large amount of n-heptane to precipitate a resin, and the resin is filtered and recovered to obtain a resin A1 (copolymer) having a weight ^average molecular weight of about 8.0 × 103 in a yield of 68. Obtained in%. This resin A1 has the following structural units.

Synthesis Example 2 [Synthesis of resin A2]
As the monomer, a monomer (a1-4-2), a monomer (a1-1-3), a monomer (a1-2-6) and a monomer (a3-1-1) are used, and the molar ratio [monomer (a1-4)] is used. -2): Monomer (a1-1-3): Monomer (a1-2-6): Monomer (a3-4-2)] is synthesized except that they are mixed so as to have a ratio of 35:25:35: 5. By the same method as in Example ¹ , a resin A1 (polymer) having a weight average molecular weight of about 8.0 × 103 was obtained in a yield of 65%. This resin A2 has the following structural units.

Synthesis Example 3 [Synthesis of resin A3]
As the monomer, a monomer (a1-4-2), a monomer (a1-1-3) and a monomer (a1-2-6) are used, and the molar ratio thereof [monomer (a1-4-2): monomer (a1-1-1). -3): Monomer (a1-2-6)] was mixed so that the ratio was 35:25:40, but the weight average molecular weight was about 7.6 × 10 ³ by the same method as in Synthesis Example 1. A certain resin A1 (copolymer) was obtained in a yield of 64%. This resin A3 has the following structural units.

Synthesis Example 4 [Synthesis of resin A4]
As the monomer, a monomer (a2-2-1), a monomer (a1-1-3), a monomer (a1-2-6) and a monomer (a3-1-1) are used, and the molar ratio [monomer (a1-4)] is used. -2): Monomer (a1-1-3): Monomer (a1-2-6): Monomer (a3-4-2)] are mixed so as to have a ratio of 35:25:35: 5, and further. , 1.5 times by mass of methyl isobutyl ketone was mixed with this monomer mixture with respect to the total mass of all the monomers. Azobisisobutyronitrile as an initiator was added to the obtained mixture so as to be 7 mol% with respect to the total number of moles of all the monomers, and this was polymerized by heating at 75 ° C. for about 5 hours. Was done. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin is added to a mixed solvent of methanol / water, repulped, and then filtered, which is a purification operation performed twice to obtain a resin A4 (copolymer) having a weight ^average molecular weight of about 8.1 × 103. It was obtained with a yield of 61%. This resin A4 has the following structural units.

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

＜クエンチャー（Ｃ）＞
Ｃ１：特開２０１１－３９５０２号公報記載の方法で合成

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 A4: Resin A1 to Resin A4
<Acid generator (B)>
B1-25: Salt represented by the formula (B1-25); Synthesized by the method described in JP-A-2011-126869 B1-41: Salt represented by the formula (B1-41); JP-A-2016-047815 Synthesized by the method described in JP-A-B1-X1: Synthesized by the method described in JP2012-229206 B1-X2: Synthesized by the method described in JP-A-2012-234155 B1-X3: Synthesized by the method described in JP-A-2007-145822 Synthesized by the method of

<Quencher (C)>
C1: Synthesized by the method described in JP-A-2011-390502.

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

<Solvent (E)>
Propylene Glycol Monomethyl Ether Acetate 400 Parts Propylene Glycol Monomethyl Ether 100 Parts γ-Butyrolactone 5 Parts

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

Line edge roughness evaluation (LER): The fluctuation width of the unevenness of the side wall surface of the resist pattern manufactured with effective sensitivity was measured with a scanning electron microscope, and the line edge roughness was determined. The results are shown in Table 3.

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

Claims (8)

A salt represented by the formula (I).

[In formula (I),
^Q1 and ^Q2 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
R ¹ and R ² independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² may be the same or different from each other.
X ¹ represents * -CO-O-, * -O-CO-, * -O-CO-O- or * -O-, and * is C (R ¹ ) (R ² ) or C (Q). ¹ ) Represents the binding position with ( ^Q2 ).
A ¹ represents a divalent hydrocarbon group having 2 to 36 carbon atoms which may have a substituent, and -CH _2- contained in the hydrocarbon group is -O-, -S-, -C. It may be replaced with (= O)-or -SO _2- .
A ² represents a divalent alicyclic saturated hydrocarbon group having 2 to 36 carbon atoms which may have a substituent, and -CH _2- contained in the alicyclic saturated hydrocarbon group is -O. -, -S-, -C (= O)-or-SO ₂ -may be replaced.
R ³ and R ⁴ each independently represent a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms.
R ⁵ represents a hydroxy group, a group represented by the formula (aa1) or the formula (aa2).

(In equation (aa1),
R ¹² , R ¹³ and R ¹⁴ independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group combining these, or R ¹² and R ¹³ respectively. Bonds to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
n represents 0 or 1.
In formula (aa2),
R ¹⁵ and R ¹⁶ independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ¹⁷ represents a hydrocarbon group having 1 to 20 carbon atoms, or R ¹⁶ and R ¹⁷ represent each other. A divalent heterocyclic group having 3 to 20 carbon atoms is formed together with the carbon atom and the oxygen atom to which they are bonded, and the hydrocarbon group and -CH _2- contained in the divalent heterocyclic group are contained in the hydrocarbon group and the divalent heterocyclic group. It may be replaced by -O- or -S-. )
Z ⁺ represents an organic cation. ] The salt according to claim 1, wherein X ¹ is * -CO-O-. A ¹ Is a divalent alicyclic saturated hydrocarbon group having 2 to 36 carbon atoms which may have a substituent (-CH contained in the alicyclic saturated hydrocarbon group). ₂ -Is -O-, -S-, -C (= O)-or -SO ₂ It may be replaced with-. ). The salt according to claim 1 or 2. A ¹ and A ² are independently composed of a divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms and an arcandyl group having 1 to 18 carbon atoms. The salt according to any one of claims 1 to 3, which is a divalent hydrocarbon group formed from. The acid generator containing the salt according to any one of claims 1 to 4. A resist composition containing the acid generator according to claim 5 and a resin containing a structural unit having an acid unstable group. The resist composition according to claim 6, further comprising a salt that generates an acid having a lower acidity than the acid generated from the acid generator. (1) A step of applying the resist composition according to claim 6 or 7 onto a substrate.
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
(4) Step of heating the composition layer after exposure, and (5) Step of developing the composition layer after heating,
A method for manufacturing a resist pattern including.