JP7044563B2 - Method for Producing Carboxylate, Carboxylic Acid Generator, Resist Composition and Resist Pattern - Google Patents

Description

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

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

Japanese Unexamined Patent Publication No. 2014-88367

In the resist composition containing the above salt, the mask error factor (MEF) of the obtained resist pattern may not always be satisfactory.

［式（Ｉ）中、
Ｘ^a及びＸ^bは、それぞれ独立に、酸素原子又は硫黄原子を表す。
Ｘ^１は、置換基を有してもよい炭素数１～２４の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－Ｓ（Ｏ）_２－に置き換わっていてもよい。
Ｌ^１及びＬ^２は、それぞれ独立に、単結合又は置換基を有してもよい炭素数１～１２の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－Ｓ（Ｏ）_２－に置き換わっていてもよい。
Ｒ^１及びＲ^２は、それぞれ独立に、置換基を有してもよい炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－Ｓ（Ｏ）_２－に置き換わっていてもよい。
Ｚ１^＋は、有機カチオンを表す。］
［２］Ｘ^１が、置換基を有してもよい炭素数１～２４の脂環式炭化水素基である［１］に記載のカルボン酸塩。
［３］Ｘ^１が、炭素数１～６のアルカントリイル基、式（ｗ１－１）で表される基、式（ｗ１－２）で表される基、式（ｗ１－３）で表される基又は式（ｗ１－６）で表される基である［１］又は［２］に記載のカルボン酸塩。

［式（ｗ１－１）、式（ｗ１－２）、式（ｗ１－３）及び式（ｗ１－６）中、
環に含まれる水素原子は、ヒドロキシ基、ハロゲン原子、炭素数１～１２のアルキル基、炭素数１～１２のアルコキシ基、炭素数２～１３のアルコキシカルボニル基、炭素数２～１３のアルキルカルボニル基、炭素数２～１３のアルキルカルボニルオキシ基、炭素数３～１２の脂環式炭化水素基又は炭素数６～１０の芳香族炭化水素基で置換されていてもよい。］
［４］［１］～［３］のいずれかに記載のカルボン酸塩を含有するカルボン酸発生剤。
［５］［４］に記載のカルボン酸発生剤、該カルボン酸発生剤以外の酸発生剤及び酸不安定基を有する樹脂を含有するレジスト組成物。
［６］前記カルボン酸発生剤以外の酸発生剤から発生する酸よりも酸性度の弱い酸を発生する塩を含有する［５］に記載のレジスト組成物。
［７］（１）［５］又は［６］に記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層に露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] Carboxylate represented by the formula (I).

[In formula (I),
X ^a and X ^b independently represent an oxygen atom or a sulfur atom, respectively.
X ¹ represents a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH _2- contained in the hydrocarbon group is -O-, -S-, -CO- or-. It may be replaced with S (O) _2- .
L ¹ and L ² each independently represent a hydrocarbon group having 1 to 12 carbon atoms which may have a single bond or a substituent, and -CH _2- contained in the hydrocarbon group is -O-. , -S-, -CO- or -S (O) ₂ -may be replaced.
R ¹ and R ² each independently represent an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and —CH ₂ − contained in the alicyclic hydrocarbon group is It may be replaced with -O-, -S-, -CO- or -S (O) _2- .
Z1 ⁺ represents an organic cation. ]
[2] The carboxylate according to [1], wherein X ¹ is an alicyclic hydrocarbon group having 1 to 24 carbon atoms which may have a substituent.
[3] X ¹ is an alkanetriyl group having 1 to 6 carbon atoms, a group represented by the formula (w1-1), a group represented by the formula (w1-2), and a group represented by the formula (w1-3). The carboxylate according to [1] or [2], which is a group to be used or a group represented by the formula (w1-6).

[In the formula (w1-1), the formula (w1-2), the formula (w1-3) and the formula (w1-6),
The hydrogen atom contained in the ring is a hydroxy group, a halogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 13 carbon atoms, and an alkylcarbonyl having 2 to 13 carbon atoms. It may be substituted with a group, an alkylcarbonyloxy group having 2 to 13 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms. ]
[4] The carboxylic acid generator containing the carboxylic acid salt according to any one of [1] to [3].
[5] A resist composition containing the carboxylic acid generator according to [4], an acid generator other than the carboxylic acid generator, and a resin having an acid unstable group.
[6] The resist composition according to [5], which contains a salt that generates an acid having a weaker acidity than an acid generated from an acid generator other than the carboxylic acid generator.
[7] (1) A step of applying the resist composition according to [5] or [6] 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.

Provided are a salt capable of producing a resist pattern having a good mask error factor (MEF) and a resist composition containing the salt.

In the present specification, the "(meth) acrylic monomer" is derived from a monomer having a structure of "CH ₂ = CH-CO-" and a monomer having a structure of "CH ₂ = C (CH ₃ ) -CO-". Means at least one species selected from the group of Similarly, "(meth) acrylate" and "(meth) acrylic acid" are "at least one selected from the group consisting of acrylate and methacrylate" and "at least one selected from the group consisting of acrylic acid and methacrylic acid, respectively". Means. In addition, any of the groups described in the present specification that can have both a linear structure and a branched structure may be used. If a steric isomer is present, it includes all steric isomers.
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、
Ｘ^a及びＸ^bは、それぞれ独立に、酸素原子又は硫黄原子を表す。
Ｘ^１は、置換基を有してもよい炭素数１～２４の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－Ｓ（Ｏ）_２－に置き換わっていてもよい。
Ｌ^１及びＬ^２は、それぞれ独立に、単結合又は炭素数１～１２の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－Ｓ（Ｏ）_２－に置き換わっていてもよい。
Ｒ^１及びＲ^２は、それぞれ独立に、置換基を有してもよい炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－Ｓ（Ｏ）_２－に置き換わっていてもよい。
Ｚ１^＋は、有機カチオンを表す。］ [Carboxylate (I)]
The carboxylic acid salt of the present invention is a carboxylic acid salt represented by the following formula (I) (hereinafter, may be referred to as "carboxylic acid salt (I)").

[In formula (I),
X ^a and X ^b independently represent an oxygen atom or a sulfur atom, respectively.
X ¹ represents a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH _2- contained in the hydrocarbon group is -O-, -S-, -CO- or-. It may be replaced with S (O) _2- .
L ¹ and L ² each independently represent a single bond or a hydrocarbon group having 1 to 12 carbon atoms, and -CH _2- contained in the hydrocarbon group is -O-, -S-, -CO-. Alternatively, it may be replaced with −S (O) _2- .
R ¹ and R ² each independently represent an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and —CH ₂ − contained in the alicyclic hydrocarbon group is It may be replaced with -O-, -S-, -CO- or -S (O) _2- .
Z1 ⁺ represents an organic cation. ]

X ^a and X ^b are preferably the same atom, and more preferably both oxygen atoms.

Examples of the hydrocarbon group represented by X ¹ include an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a group in which these are combined. In addition, -CH _2- contained in these hydrocarbon groups may be replaced with -O-, -S-, -CO- or -S (O) _2- .
Examples of the aliphatic hydrocarbon group include an alkanetriyl group, an alicyclic hydrocarbon group, or a group in which these are combined.
Specific examples of the alkanetriyl group include a methanetriyl group, an ethanetriyl group, a propanetriyl group, a butantryyl group, a pentanetriyl group, a hexanetriyl group, a heptanthryyl group, an octantriyl group, a nonantriyl group, and a decantryyl group. , Undecantryyl group, dodecantryyl group and the like.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic.
Examples of the monocyclic alicyclic hydrocarbon group include a cyclobutanetriyl group, a cyclopentanetriyl group, a cyclohexanetriyl group, a cyclooctanetriyl group and the like.
Examples of the polycyclic alicyclic hydrocarbon group include a norbornane triyl group, a norbornane triyl group, and an adamantane triyl group.
Examples of the aromatic hydrocarbon group include a benzenetriyl group, a naphthalenetriyl group, an anthracene triyl group, and a methylbenzenetriyl group.

炭素数６～１０の芳香族炭化水素基としては、フェニル基、ナフチル基、トリル基、キシリル基、シクロヘキシルフェニル基等が挙げられる。
組み合わせた基としては、ヒドロキシ基と炭素数１～１２のアルキル基とを組み合わせた基、炭素数１～１２のアルキル基と炭素数６～１０の芳香族炭化水素基とを組み合わせた基等が挙げられる。
ヒドロキシ基と炭素数１～１２のアルキル基とを組み合わせた基としては、ヒドロキシメチル基、ヒドロキシエチル基等の炭素数１～１２のヒドロキシアルキル基等が挙げられる。
炭素数１～１２のアルキル基と炭素数６～１０の芳香族炭化水素基とを組み合わせた基としては、ベンジル基等の炭素数７～２２のアラルキル基等が挙げられる。 The hydrocarbon group represented by X ¹ has a total carbon number of 1 to 24, and may further have one or a plurality of substituents. Examples of the substituent include a hydroxy group, a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 13 carbon atoms, and an alkyl having 2 to 13 carbon atoms. Examples thereof include a carbonyl group, an alkylcarbonyloxy group having 2 to 13 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and an aromatic hydrocarbon group having 6 to 10 carbon atoms.
Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group and a dodecyl group. ..
The alkoxy group having 1 to 12 carbon atoms includes a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group and an undecyloxy group. Groups, dodecyloxy groups and the like can be mentioned.
The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms and the alkylcarbonyloxy group having 2 to 13 carbon atoms are groups in which a carbonyl group or a carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Can be mentioned.
Examples of the alicyclic hydrocarbon group having 3 to 12 carbon atoms include the groups shown below. ** is a bond with the ring.

Examples of the aromatic hydrocarbon group having 6 to 10 carbon atoms include a phenyl group, a naphthyl group, a tolyl group, a xsilyl group, a cyclohexylphenyl group and the like.
Examples of the combined group include a group in which a hydroxy group and an alkyl group having 1 to 12 carbon atoms are combined, a group in which an alkyl group having 1 to 12 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms are combined, and the like. Can be mentioned.
Examples of the group in which a hydroxy group and an alkyl group having 1 to 12 carbon atoms are combined include a hydroxyalkyl group having 1 to 12 carbon atoms such as a hydroxymethyl group and a hydroxyethyl group.
Examples of the group in which an alkyl group having 1 to 12 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms are combined include an aralkyl group having 7 to 22 carbon atoms such as a benzyl group.

［式（ｗ１－１）～式（ｗ１－１１）中、
環に含まれる水素原子は、ヒドロキシ基、ハロゲン原子、シアノ基、炭素数１～１２のアルキル基、炭素数１～１２のアルコキシ基、炭素数２～１３のアルコキシカルボニル基、炭素数２～１３のアルキルカルボニル基、炭素数２～１３のアルキルカルボニルオキシ基、炭素数３～１２の脂環式炭化水素基又は炭素数６～１０の芳香族炭化水素基で置換されていてもよい。
＊は結合手を表す。なお、式（ｗ１－９）～式（ｗ１－１１）においては、３つの結合手は任意の位置とすることができる。］ The hydrocarbon group represented by X ¹ is preferably an alicyclic hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and is an alcantryl group or carbon having 1 to 6 carbon atoms. It is more preferably an alicyclic hydrocarbon group having a number of 3 to 18, an alcantryl group having 1 to 6 carbon atoms, and a group represented by the formulas (w1-1) to (w1-11). Is more preferable, an alkylantryl group having 1 to 6 carbon atoms, a group represented by the formula (w1-1), a group represented by the formula (w1-2), and a group represented by the formula (w1-3). Alternatively, it is more preferably a group represented by the formula (w1-6), and particularly preferably a polycyclic hydrocarbon group, particularly preferably a group represented by the formula (w1-1).

[In the formula (w1-1) to the formula (w1-11),
The hydrogen atom contained in the ring is a hydroxy group, a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 13 carbon atoms, and 2 to 13 carbon atoms. Alkoxycarbonyl group, alkylcarbonyloxy group having 2 to 13 carbon atoms, alicyclic hydrocarbon group having 3 to 12 carbon atoms, or aromatic hydrocarbon group having 6 to 10 carbon atoms may be substituted.
* Represents a bond. In the equations (w1-9) to (w1-11), the three bonds can be at arbitrary positions. ]

The hydrocarbon groups represented by L ¹ and L ² have a total carbon number of 1 to 12, and may further have one or a plurality of substituents. Examples of the substituent include a hydroxy group, a cyano group, a carboxyl group, an alkoxy group having 1 to 12 carbon atoms, an alkylcarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyloxy group having 2 to 13 carbon atoms, and these groups. A group that combines two or more types can be mentioned.
Examples of the alkoxy group having 1 to 12 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group include the same as those exemplified as the above-mentioned substituents.
As the hydrocarbon group represented by L ¹ and L ² , an alkanediyl group is preferable. Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group and the like. Chain alkanediyl group;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- 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.
When the hydrocarbon group represented by X ¹ , L ¹ and L ² has a substituent or is contained in the hydrocarbon group -CH _2- is -O-, -S-, -CO- or -S (O). When replaced with _2- , the number of carbon atoms before the replacement is taken as the total number of carbon atoms of the hydrocarbon group.

The alicyclic hydrocarbon group represented by R ¹ and R ² has a total carbon number of 3 to 18, and may further have one or a plurality of substituents. Examples of the substituent include a hydroxy group, a halogen atom, a cyano group, a carboxyl group, an alkoxy group having 1 to 12 carbon atoms, an alkylcarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyloxy group having 2 to 13 carbon atoms, and these. A group in which two or more kinds of groups are combined can be mentioned.
Examples of the alkoxy group having ¹ to 12 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group are the same as those exemplified as the substituent of the ring W1.
-CH _2- contained in the alicyclic hydrocarbon group represented by R ¹ and R ² may be replaced with -O-, -S-, -CO- or -S (O) _2- .
When the alicyclic hydrocarbon group represented by R ¹ and R ² has a substituent or -CH _2- contained in the alicyclic hydrocarbon group is -O-, -S-, -CO- or-. When it is replaced with S (O) _2- , the number of carbon atoms before the replacement is taken as the total number of carbon atoms of the alicyclic hydrocarbon group.

Examples of the alicyclic hydrocarbon group represented by R ¹ and R ² include groups represented by the formulas (Y1) to (Y40).

It is preferably a group represented by any one of the formula (Y1) to the formula (Y20), the formula (Y30), the formula (Y31), the formula (Y39) or the formula (Y40), and more preferably the formula (Y11). It is a group represented by the formula (Y15), the formula (Y16), the formula (Y19), the formula (Y30), the formula (Y31), the formula (Y39) or the formula (Y40), and more preferably the formula (Y11). It is a group represented by the formula (Y15), the formula (Y30), the formula (Y39) or the formula (Y40).

The substituent of R ¹ or R ² is preferably a group having a hydroxy group or a halogen atom, and more preferably a hydroxy group or a fluorine atom.

The alicyclic hydrocarbon group represented by R ¹ and R ² is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably a substituent. It is an adamantyl group which may have a substituent or a cyclohexyl group which may have a substituent (-CH _2- constituting these groups is -O-, -S-, -CO- or -S. (O) It may be replaced with _2- ), more preferably an adamantyl group, a cyclohexyl group, a hydroxyadamantyl group, an oxoadamantyl group or a group represented by the following, and even more preferably a cyclohexyl group.

Examples of the anion in the carboxylate represented by the formula (I) include the anions described below.

Examples of the organic cation include an organic onium cation, an organic sulfonium cation, an organic iodine cation, an organic ammonium cation, a benzothiazolium cation, an organic phosphonium cation and the like. Among these, organic sulfonium cations and organic iodonium cations are preferable, and aryl sulfonium cations are more preferable. Specifically, the 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). Can be mentioned.

式（ｂ２－１）～式（ｂ２－４）において、
Ｒ^b4～Ｒ^b6は、それぞれ独立に、炭素数１～３０の脂肪族炭化水素基、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、互いに結合してそれらが結合する硫黄原子と一緒になって環を形成してもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b7及びＲ^b8は、それぞれ独立に、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
ｍ２及びｎ２は、それぞれ独立に０～５のいずれかの整数を表す。
ｍ２が２以上のとき、複数のＲ^b7は同一でも異なってもよく、ｎ２が２以上のとき、複数のＲ^b8は同一でも異なってもよい。
Ｒ^b9及びＲ^b10は、それぞれ独立に、炭素数１～３６の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、互いに結合してそれらが結合する硫黄原子と一緒になって環を形成してもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b11は、水素原子、炭素数１～３６の脂肪族炭化水素基、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、互いに結合してそれらが結合する－ＣＨ－ＣＯ－を含めて環を形成していてもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b13～Ｒ^b18は、それぞれ独立に、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
Ｌ^b31は、硫黄原子又は酸素原子を表す。
ｏ２、ｐ２、ｓ２、及びｔ２は、それぞれ独立に、０～５のいずれかの整数を表す。
ｑ２及びｒ２は、それぞれ独立に、０～４のいずれかの整数を表す。
ｕ２は０又は１を表す。
ｏ２が２以上のとき、複数のＲ^b13は同一又は相異なり、ｐ２が２以上のとき、複数のＲ^b14は同一又は相異なり、ｑ２が２以上のとき、複数のＲ^b15は同一又は相異なり、ｒ２が２以上のとき、複数のＲ^b16は同一又は相異なり、ｓ２が２以上のとき、複数のＲ^b17は同一又は相異なり、ｔ２が２以上のとき、複数のＲ^b18は同一又は相異なる。

In 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 bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH _2- contained in the ring may be -O-, -S- or. It may be replaced with -CO-.
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 bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH _2- contained in the ring may be -O-, -S- or. It may be replaced with -CO-.
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 bonded to each other to form a ring including -CH-CO- to which they are bonded, and -CH _2- contained in the ring is -O-, -S. -Or -CO- may be replaced.
R ^b13 to R ^b18 independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represent an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, multiple R ^b13s are the same or different, when p2 is 2 or more, multiple R ^b14s are the same or different, and when q2 is 2 or more, multiple R ^b15s are the same or different. , When r2 is 2 or more, the plurality of R ^b16s are the same or different, when s2 is 2 or more, the plurality of R ^b17s are the same or different, and when t2 is 2 or more, the plurality of R ^b18s are the same or different. different.

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

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

Examples of the alicyclic hydrocarbon group in which the hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group and a 2-ethyladamantan-2-yl group. , 2-Isopropyl adamantan-2-yl group, methylnorbornyl group, isobornyl group and the like. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total carbon number of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.

Examples of the aromatic hydrocarbon group include phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group and p-adamantylphenyl group. , Biphenylyl group, naphthyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group and other aryl groups.
When the aromatic hydrocarbon group contains an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, the aliphatic hydrocarbon group having 1 to 18 carbon atoms and the alicyclic hydrocarbon having 3 to 18 carbon atoms are used. Group is preferred.
Examples of the aromatic hydrocarbon group in which the hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group and the like.
Examples of the aliphatic hydrocarbon group in which the hydrogen atom is replaced with an aromatic hydrocarbon group include an aralkyl group such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group and a naphthylethyl 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 alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group and the like.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
The alkylcarbonyloxy group includes a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, and a pentylcarbonyloxy group. , Hexylcarbonyloxy group, octylcarbonyloxy group, 2-ethylhexylcarbonyloxy group and the like.

Rings formed by the bonds of R ^b4 and R ^b5 together with the sulfur atoms they bond to can be monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. It may be a ring of. Examples of this ring include a ring having 3 to 18 carbon atoms, preferably a ring having 4 to 18 carbon atoms. Further, the ring containing a sulfur atom may be a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and examples thereof include the following rings.

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

Among the cations (b2-1) to cations (b2-4), the cation (b2-1) is 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.

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

The carboxylate (I) is preferably a combination of the above-mentioned anions and cations.
These anions and cations can be combined arbitrarily.
Examples of the carboxylate (I) include the salts shown in Table 1.
For example, the carboxylate (I-1) in Table 1 represents the following salt in which the carboxylic acid anion is (I-a-1) and the cation is (b2-c-1).

Among them, the carboxylic acid salt (I) includes a carboxylate (I-1), a carboxylate (I-2), a carboxylate (I-15), a carboxylate (I-16), and a carboxylic acid. Salt (I-19), Carboxylate (I-20), Carboxylate (I-33), Carboxylate (I-34), Carboxylate (I-37), Carboxylate (I-38) ), Carboxylate (I-51), Carboxylate (I-52), Carboxylate (I-55), Carboxylate (I-56), Carboxylate (I-69), Carboxylate (I-70), Carboxylate (I-73), Carboxylate (I-74), Carboxylate (I-87), Carboxylate (I-88), Carboxylate (I-91) , Carboxylate (I-93), Carboxylate (I-94), Carboxylate (I-96), Carboxylate (I-97), Carboxylate (I-99), Carboxylate ( I-100), carboxylate (I-102), carboxylate (I-103) and carboxylate (I-105) are preferred, and carboxylate (I-1), carboxylate (I-2). ), Carboxylate (I-15), Carboxylate (I-16), Carboxylate (I-19), Carboxylate (I-20), Carboxylate (I-33), Carboxylate (I-34), Carboxylate (I-37), Carboxylate (I-38), Carboxylate (I-51), Carboxylate (I-52), Carboxylate (I-55) , Carboxylate (I-56), Carboxylate (I-69), Carboxylate (I-70), Carboxylate (I-73), Carboxylate (I-74), Carboxylate ( I-87) and carboxylate (I-88) are more preferred.

（式中、Ｘ^a、Ｘ^b、Ｌ^１、Ｌ^２、Ｒ^１、Ｒ^２、Ｘ^１及びＺ１は上記と同じ意味を表す。
）
この反応における溶媒としては、メタノール等が挙げられる。
反応は、１０℃～８０℃の温度範囲で、０．５～２４時間行うことが好ましい。
式（Ｉ－ａ）で表される塩は、以下で表される塩などが挙げられる。

<Manufacturing method of carboxylate (I)>
The salt represented by the formula (I) is obtained by reacting the salt represented by the formula (Ia) with the compound represented by the formula (Ib) in a solvent in the presence of silver oxide. Can be manufactured.

(In the formula, X ^a , X ^b , L ¹ , L ² , R ¹ , R ² , X ¹ and Z 1 have the same meanings as above.
)
Examples of the solvent in this reaction include methanol and the like.
The reaction is preferably carried out in a temperature range of 10 ° C to 80 ° C for 0.5 to 24 hours.
Examples of the salt represented by the formula (Ia) include salts represented by the following.

（式中、Ｘ^a、Ｘ^b、Ｌ^１、Ｌ^２、Ｒ^１、Ｒ^２及びＸ^１は上記と同じ意味を表す。）
この反応における酸触媒としては、硫酸、ｐ－トルエンスルホン酸等が挙げられる。
この反応における溶媒としては、クロロホルム、アセトニトリル、ジメチルホルムアミド等が挙げられる。
反応は、１０℃～８０℃の温度範囲で、０．５～２４時間行うことが好ましい。 The compound represented by the formula (Ib) is a compound represented by the formula (Ic), a compound represented by the formula (Id1), and a compound represented by the formula (Id2). Can be produced by reacting with and in a solvent under an acid catalyst and then hydrolyzing.

(In the formula, X ^a , X ^b , L ¹ , L ² , R ¹ , R ² and X ¹ have the same meanings as above.)
Examples of the acid catalyst in this reaction include sulfuric acid, p-toluenesulfonic acid and the like.
Examples of the solvent in this reaction include chloroform, acetonitrile, dimethylformamide and the like.
The reaction is preferably carried out in a temperature range of 10 ° C to 80 ° C for 0.5 to 24 hours.

At the time of hydrolysis, sodium hydroxide or the like is added as a catalyst.
The reaction is preferably carried out in a temperature range of 10 ° C to 80 ° C for 0.5 to 24 hours.

式（Ｉ－ｄ１）及び式（Ｉ－ｄ２）で表される化合物としては、下記式で表される化合物等が挙げられ、市場より容易に入手することができる。

Examples of the compound represented by the formula (Ic) include compounds represented by the following.

Examples of the compound represented by the formula (Id1) and the formula (Id2) include a compound represented by the following formula, which can be easily obtained from the market.

[Acid generator]
The carboxylate (I) of the present invention can act as an acid generator in the resist composition. When the carboxylate (I) is used as an acid generator in the resist composition, two or more kinds of the carboxylate (I) may be contained.
Further, as will be described later, the acid generator of the present invention further contains an acid generator known in the resist field other than the carboxylate (I) (hereinafter, may be referred to as “acid generator (B)”). You may.

<Acid generator (B)>
As the acid generator (B), either a nonionic type or an ionic type may be used. Examples of the nonionic acid generator include sulfonate esters (eg 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (eg disulfone, etc.). Ketosulfone, sulfonyldiazomethane) and the like. As the ionic acid generator, an onium salt containing an onium cation (for example, a diazonium salt, a phosphonium salt, a sulfonium salt, an iodonium salt) is typical. 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 the radiation described in the above can be used. Further, a compound produced by a known method may be used. The acid generator (B) may be used in combination of two or more.

［式（Ｂ１）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。
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。
Ｚ^＋は、有機カチオンを表す。］ The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a fluorine-containing sulfonic acid generator, and is a salt represented by the formula (B1) (hereinafter, “acid generator (B1)””. In some cases).

[In formula (B1),
^Q1 and ^Q2 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—.
Z ⁺ represents an organic cation. ]

The perfluoroalkyl groups represented by ^Q1 and ^Q2 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 ^Q1 and ^Q2 are independently fluorine atoms or trifluoromethyl groups, and it is more preferable that both are fluorine atoms.

Examples of the divalent saturated hydrocarbon group of 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- in the divalent saturated hydrocarbon group of L ^b1 is replaced with -O- or -CO- are any of the formulas (b1-1) to (b1-3). The group represented by is mentioned. In addition, in equations (b1-1) to (b1-3) and equations (b1-4) to (b1-11) which are specific examples thereof, * represents a bond 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 of L ^b1 is replaced with -O- or -CO- is a group represented by the formula (b1-1) or the formula (b1-3). Is preferable.

［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.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-4) include the following.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-5) include the following.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-6) include the following.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-7) include the following.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-8) include the following.

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

Among the groups represented by the formula (b1-3), the groups represented by the formula (b1-9) include the following.

Among the groups represented by the formula (b1-3), the groups represented by the formula (b1-10) include the following.

Among the groups represented by the formula (b1-3), the groups represented by the formula (b1-11) include the following.

The alicyclic hydrocarbon group represented by Y is the same as that of the alicyclic hydrocarbon group represented by R ¹ and R ² in the carboxylate (I), for example, the formulas (Y1) to (Y1) to (form). Y11), groups represented by the formulas (Y36) to (Y38) can be mentioned.
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. There may be more than one. Such groups include the same alicyclic hydrocarbon groups represented by ^R1 and ^R2 in the carboxylate (I), formulas (Y12) to (Y35), formulas (Y39), formulas. Examples include the group represented by (Y40).

Y is preferably a group represented by any one of the formula (Y1) to the formula (Y20), the formula (Y30), the formula (Y31), the formula (Y39) or the formula (Y40), and more preferably the formula. (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y30), formula (Y31), formula (Y39) or formula (Y40), more preferably formula. (Y11), formula (Y15), formula (Y30), formula (Y39) or formula (Y40).
When Y constitutes a spiro ring of the formula (Y28) to the formula (Y33), the formula (Y39), the formula (Y40), etc., the alkanediyl group between the two oxygen atoms has one or more fluorine atoms. Is preferable. 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) 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 methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, an adamantyl group and the like.
Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group and a p-adamantylphenyl group; a trill group, a xylyl group, a cumenyl group and a mesityl group. , Biphenyl group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl and the like.
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.

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 sulfonic acid anion in the salt represented by the formula (B1) include anions represented by the formulas (B1-A-1) to (B1-A-55) [hereinafter, "anion (B1)" according to the formula number. -A-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 (BI-A-36) to formula (BI-A-40), formula (B1-A-47) to formula (B1-A-55). Anions are more preferred.

Here, R ⁱ² to R ⁱ⁷ are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R ⁱ⁸ is formed, for example, by an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. Group, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L ⁴⁴ is a single bond or an alkanediyl group having 1 to 4 carbon atoms. ^Q1 and ^Q2 have the same meanings as above.
Specific examples of the sulfonic acid anion in the salt represented by the formula (B1) include anions described in JP-A-2010-204646.

Examples of the sulfonic acid anion in the salt represented by the preferred formula (B1) include anions represented by the formulas (B1a-1) to (B1a-34).

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-34) is preferable.

Examples of the Z ⁺ organic cation include an organic onium cation, for example, 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. These include, more preferably aryl sulfonium cations.
Examples of Z ⁺ in the formula (B1) include the same as the cation Z1 ⁺ in the carboxylate (I).

The acid generator (B1) is a combination of the above-mentioned sulfonic acid anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the acid generator (B1), the formulas (B1a-1) to (B1a-3), formulas (B1a-7) to formulas (B1a-16), formulas (B1a-18), and formulas (B1a-) are preferable. 19), a combination of an anion represented by any of the formulas (B1a-22) to (B1a-34) and a cation (b2-1) or a cation (b2-3) can be mentioned.

Examples of the acid generator (B1) preferably include those represented by the formulas (B1-1) to (B1-48), and among them, those containing an arylsulfonium cation are preferable, and the acid generator (B1) is preferably represented by the formula (B1-1). -Formula (B1-3), Formula (B1-5) -Formula (B1-7), Formula (B1-11) -Formula (B1-14), Formula (B1-17), Formula (B1-20), Those represented by the formulas (B1-21) to (B1-26), the formula (B1-29), and the formulas (B1-31) to (B1-48) are particularly preferable.

The acid generator (B) may contain one kind alone or a plurality of kinds.
When the acid generator of the present invention contains the acid generator (B) in addition to the carboxylate (I), the content ratio (mass ratio,) of the carboxylate (I) and the acid generator (B). The carboxylate (I): acid generator (B)) is usually less than 1:99-100: greater than 0, preferably 1:99-99: 1, more preferably 2:98-98: 2. , More preferably 5:95 to 95: 5, and even more preferably 30:70 to 70:30.

[Resist composition]
The resist composition of the present invention contains a carboxylate (I), an acid generator other than the carboxylate (I), and a resin having an acid unstable group (hereinafter, may be referred to as "resin (A)"). .. The term "acid-unstable group" as used herein means a group having a leaving group, which is removed by contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group). ..
The resist composition preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") and / or a solvent (hereinafter sometimes referred to as "solvent (E)").

<Acid generator>
As described above, the acid generator contains a carboxylate (I) and a known acid generator other than the carboxylate (I) (preferably a sulfonic acid generator).
In the resist composition of the present invention, the content of the acid generator is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 40 parts by mass or less with respect to 100 parts by mass of the resin (A). (More preferably, it is 35 parts by mass or less).

<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). The structural unit other than the structural unit (a1) includes a structural unit having no acid unstable group (hereinafter, may be referred to as “structural unit (s)”), a structural unit (a1), and a structural unit other than the structural unit (s). Structural unit (for example, a structural unit having a halogen atom described later (hereinafter, may be referred to as "structural unit (a4)"), a structural unit having a non-desorbed hydrocarbon group described later (hereinafter referred to as "structural unit (a5)"). ) 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価の脂環式炭化水素基を形成する。
ｍａ及びｎａは、それぞれ独立して、０又は１を表し、ｍａ及びｎａの少なくとも一方は１を表す。
＊は結合手を表す。］

［式（２）中、Ｒ^a1’及びＲ^a2’は、それぞれ独立に、水素原子又は炭素数１～１２の炭化水素基を表し、Ｒ^a3’は、炭素数１～２０の炭化水素基を表すか、Ｒ^a2’及びＲ^a3’は互いに結合してそれらが結合する炭素原子及びＸとともに炭素数３～２０の２価の複素環基を形成し、該炭化水素基及び該２価の複素環基に含まれる－ＣＨ₂－は、－Ｏ－又は－Ｓ－で置き換わってもよい。
Ｘは、酸素原子又は硫黄原子を表す。
ｎａ’は、０又は１を表す。
＊は結合手を表す。］
なお、炭化水素基及び２価の複素環基に含まれる－ＣＨ₂－が－Ｏ－等に置き換わっている場合、置き換わる前の炭素数をこれらの基の総炭素数とする。 <Structural unit (a1)>
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 a group represented by the formula (1) (hereinafter, also referred to as a group (1)) and / or a group represented by the formula (2) (hereinafter, a group (2). ) Is also preferable.

[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. ]
When -CH _2- contained in the hydrocarbon group and the divalent heterocyclic group is replaced with -O- or the like, the carbon number before the replacement is taken as the total carbon number of these groups.

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, a butyl group, a pentyl group, a hexyl group, a heptyl group, an 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 (1), a 1,1-dialkylalkoxycarbonyl group (R ^a1 to R ^a3 in the formula (1) are alkyl groups, ma = 0, na = 1, preferably tert-butoxy. Carbonyl group), 2-alkyl adamantan-2-yloxycarbonyl group (in formula (1), R ^a1 and R ^a2 , together with the carbon atom to which they are bonded form an adamantyl group, where R ^a3 is alkyl Group, ma = 0, na = 1) and 1- (adamantan-1-yl) -1-alkylalkoxycarbonyl group (in formula (1), R ^a1 and R ^a2 are independent, respectively. It is an alkyl group, R ^a3 is an adamantyl group, ma = 0, na = 1) and the like, and specific examples thereof include the following groups. * Represents a bond.

Specific examples of the group (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 the group (1) is preferably a structural unit represented by the formula (a1-0) (hereinafter, structural unit (a1-0)).
), The structural unit represented by the formula (a1-1) (hereinafter, may be referred to as the structural unit (a1-1)) or the structural unit represented by the formula (a1-2) (hereinafter, the structural unit (a1)). -2) may be mentioned.). 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 structural unit (a1-1) include structural units derived from 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。］ Examples of the structural unit having the group (2) in the structural unit (a1) include structural units represented by the formula (a1-4) (hereinafter, may be referred to as “structural unit (a1-4)”). ..

[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 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 the hydrocarbon group and -CH _2- contained in the divalent hydrocarbon group are-. It may be replaced by O- or -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, pentyl group, hexyl group, perfluorohexyl group, etc. 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 the hydrocarbon groups of R ^a34 , R ^a35 and R ^a36 include an alkyl group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group, and the same groups as R a1'and R ^{a2' of} the formula (2). Can be mentioned. In particular, ^Ra36 includes an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining them. Can be mentioned.

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 an alkyl group or an alicyclic 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. The aromatic hydrocarbon group in R ^a36 is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

Examples of the structural unit (a1-4) include structural units derived from the monomers described in JP-A-2010-204646. Preferred are structural units represented by the formulas (a1-4-1) to (a1-4-8) and structural units in which a hydrogen atom corresponding to ^Ra32 is replaced with a methyl group, and more preferably. , The structural units represented by the formulas (a1-4-1) to (a1-4-5), respectively.

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。 Examples of the structural unit derived from the (meth) acrylic monomer having the group (2) include the structural unit represented by the formula (a1-5) (hereinafter, may be referred to as “structural unit (a1-5)”). Be done.

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 structural unit (a1-5) include the structural unit derived from the monomer 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 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.
The structural unit (s) preferably has a hydroxy group or a lactone ring. 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 in the structural unit (a2) include structural units 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, pentyl group, hexyl group and perfluorohexyl The group is mentioned.
R ^a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, 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, 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 of the alkoxy group of R ^a51 include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a 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 hydroxy group is preferably bonded to the o-position or p-position of the benzene ring, and more preferably to the p-position.

The structural unit (a2-A) includes the structural units represented by the formulas (a2-2-1) to (a2-2-8) and the structural unit in which the 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 structural unit (a2-A) include structural units derived from 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 having an alcoholic hydroxy group in the structural unit (a2) 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 represents 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、それぞれ独立に、－Ｏ－又は^＊－Ｏ－（ＣＨ_２）_ｋ３－ＣＯ－Ｏ－（ｋ３は１～７のいずれかの整数を表す。）で表される基を表す。
Ｌ^ａ７は、－Ｏ－、^＊－Ｏ－Ｌ^ａ８－Ｏ－、^＊－Ｏ－Ｌ^ａ８－ＣＯ－Ｏ－、^＊－Ｏ－Ｌ^ａ８－ＣＯ－Ｏ－Ｌ^ａ９－ＣＯ－Ｏ－又は^＊－Ｏ－Ｌ^ａ８－Ｏ－ＣＯ－Ｌ^ａ９－Ｏ－を表す。
Ｌ^ａ８及びＬ^ａ９は、それぞれ独立に、炭素数１～６のアルカンジイル基を表す。
＊はカルボニル基との結合手を表す。
Ｒ^ａ１８、Ｒ^ａ１９及びＲ^ａ２０は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^ａ２４は、ハロゲン原子を有してもよい炭素数１～６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^ａ２１は炭素数１～４の脂肪族炭化水素基を表す。
Ｒ^ａ２２、Ｒ^ａ２３及びＲ^ａ２５は、それぞれ独立に、カルボキシ基、シアノ基又は炭素数１～４の脂肪族炭化水素基を表す。
ｐ１は０～５のいずれかの整数を表す。
ｑ１は、０～３のいずれかの整数を表す。
ｒ１は、０～３のいずれかの整数を表す。
ｗ１は、０～８のいずれかの整数を表す。
ｐ１、ｑ１、ｒ１及び／又はｗ１が２以上のとき、複数のＲ^ａ２１、Ｒ^ａ２２、Ｒ^ａ２３及び／又はＲ^ａ２５は互いに同一であってもよく、異なってもよい。］ 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} are independently represented by -O- or ^* -O- (CH ₂ ) _k3 -CO-O- (k3 represents an integer of 1 to 7). Represents a group.
L ^a7 is -O-, ^* -OL ^a8 -O-, ^{* -OL a8-CO-O-, * -OL a8 -} CO-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 each independently 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 each independently 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 a ²⁵ include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group and a tert-butyl group. Be done.
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, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group and a hexyl group, and preferably have 1 to 4 carbon atoms. Alkyl group of, more preferably a methyl group or an ethyl group.
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 independently, preferably k3 in -O- or * -O- (CH ₂ ) _k3 -CO-O-, respectively. A group that is an integer of 1 to 4, more preferably —O— and * —O— _CH2 -CO—O—, and even more preferably an oxygen atom.
R ^a18 to R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently, preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are 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), a structural unit represented by any of the formulas (a3-3-2) and the formulas (a3-4-1) to ( ^a3-4-12 ), and Ra 18 and Ra ¹⁹ in the structural unit. A structural unit in which a methyl group corresponding to R ^a20 and R ^a24 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、
Ｒ⁵は、水素原子又はメチル基を表す。
Ｌ⁴は、単結合又は炭素数１～４の脂肪族飽和炭化水素基を表す。
Ｌ³は、炭素数１～８のペルフルオロアルカンジイル基又は炭素数３～１２のペルフルオロシクロアルカンジイル基を表す。
Ｒ⁶は、水素原子又はフッ素原子を表す。］ <Structural unit (a4)>
Examples of the structural unit (a4) include a structural unit represented by the formula (a4-0).

[In equation (a4-0),
R ⁵ 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 R5 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, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group and Examples include octadecyl groups. 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。 As the substituent contained in R ^a42 , it may have a halogen atom and a group represented by the formula (ag3). 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). ..
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.

なお、Ｒ^ａ４２で表される炭化水素基に含まれる－ＣＨ₂－が－Ｏ－等に置き換わっている場合、置き換わる前の炭素数を炭化水素基の総炭素数とする。 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.

When —CH ₂ − contained in the hydrocarbon group represented by R ^a42 is replaced with —O— or the like, the carbon number before the replacement is taken as the total carbon number of the hydrocarbon group.

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、Ｌ^5５との結合位置にある炭素原子に結合する水素原子は、炭素数１～８の脂肪族炭化水素基で置換されない。
Ｌ^5５は、単結合又は炭素数１～１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。］ <Structural unit (a5)>
Examples of the non-eliminating hydrocarbon group 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.
^L55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. .. ]

The alicyclic hydrocarbon group 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, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group and 2 -Alkyl groups such as ethylhexyl groups 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 ^L55 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、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＡ^f13との結合手を表す。） 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。 In the structural unit represented by the formula (a5-1), the group in which -CH _2- contained in the saturated hydrocarbon group is replaced with -O- or -CO- is, for example, from the formula (L1-1) to Examples thereof include groups represented by the formula (L1-4). In the following formula, * represents a bond with an oxygen atom.

In equation (L1-1),
X ^x1 represents * -O-CO- or * -CO-O- (* represents a bond with A ^f13 ) L ^x1 is a divalent aliphatic saturated hydrocarbon having 1 to 16 carbon atoms. Represents a group.
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%.

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

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, a radical polymerization method) using a monomer that leads to these structural units. be able to. 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 other than resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A).
As the resin other than the resin (A), a resin containing the structural unit (a4) (however, the resin does not include the structural unit (a1); hereinafter may be referred to as “resin (X)”) is preferable. In the resin (X), the content of the structural unit (a4) is preferably 40 mol% or more, more preferably 45 mol% or more, still more preferably 50 mol% or more, based on all the structural units of the resin (X). ..
Examples of the structural unit that the resin (X) may further include include a structural unit (a2), a structural unit (a3), a structural unit (a5), and a structural unit derived from other known monomers.
The weight average molecular weight of the resin (X) is preferably 8,000 or more (more preferably 10,000 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 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) in the resist composition 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. It is preferably 99% by mass or less. 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)>
As the quencher (C), a salt that generates an acid having a weaker acidity than the acid generated from the basic nitrogen-containing organic compound and the acid generator (B) (that is, the carboxylic acid represented by the formula (I)). Acid generators excluding salts). The content of the quencher (C) is preferably about 0.01 to 5% by mass based on the solid content of the resist composition.
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.

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

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.

The acidity of a salt that produces an acid that is weaker than the acid generated by the acid generator (B) 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 (B) is usually a salt having an acid dissociation constant of -3 <pKa, preferably -1 <. It is a salt of pKa <7, more preferably a salt of 0 <pKa <5.
Examples of the salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B) include a salt represented by the following formula and a compound represented by the formula (D) described in JP-A-2015-147926. (Hereinafter, it may be referred to as "weak acid intramolecular salt (D)"), and JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502. Examples thereof include the salts described in JP-A-2011-191745. It is preferably a weak acid intramolecular salt (D).

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

The content of the quencher (C) is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass, based on the solid content of the resist composition.

<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 a resin (A), a carboxylate (I), an acid generator (B), and, if necessary, a resin other than the resin (A) used, a solvent (E), and the like. It can be prepared by mixing a salt that generates a weakly acidic acid such as a quencher (C) or a weak acid intramolecular salt (D) and another component (F). 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 addition, in this specification, irradiation of these radiations may be generically 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, for example, 5 to 60 ° C., and the development time is preferably, for example, 5 to 300 seconds. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any 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 is suitable as 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. Yes, it is more suitable as a resist composition for ArF excimer laser 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. The analysis conditions for gel permeation chromatography are as follows.
Column: TSKgel Multipore HXL-M x 3 + guardcolumn (manufactured by Tosoh)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ℃
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－５２－ａ）で表される化合物５部及びアセトニトリル５０部を添加し、２３℃で３０分間撹拌した後、式（Ｉ－５２－ｂ）で表される化合物４．５９部を添加し、８５℃で、１５分間還流撹拌した。得られた反応物に、式（Ｉ－５２－ｃ）で表される化合物１６．５０部を添加し、８５℃で還流濃縮することにより、式（Ｉ－５２－ｄ）で表される化合物を含む溶液を得た。式（Ｉ－５２－ｄ）で表される化合物を含む溶液に、クロロホルム３３部及び５％塩酸水溶液５６部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。回収された有機層に、イオン交換水１００部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を２回行った。得られた有機層を濃縮した後、濃縮残に、式（Ｉ－５２－ｅ）で表される化合物１１．７６部及び硫酸０．０８部を仕込み、７０℃で３時間撹拌した後、２３℃まで冷却した。得られた式（Ｉ－５２－ｆ）で表される化合物を含む反応混合物に、１Ｍ水酸化ナトリウム水溶液７８部を仕込み、２３℃で３時間撹拌した後、５％塩酸水溶液６８部を仕込み、２３℃で３０分間攪拌した。得られた反応混合物に、クロロホルム１３５部及びイオン交換水４０部を仕込み、２３℃で３０分間攪拌した後、分液することにより有機層を回収した。この水洗の操作を３回行った。得られた有機層を濃縮することにより、式（Ｉ－５２－ｇ）で表される化合物５．９７部を得た。

式（Ｉ－５２－ｇ）で表される化合物５部及びメタノール１００部を添加し、２３℃で３０分間撹拌した後、酸化銀１．３９部を添加し、２３℃で３時間撹拌した。得られた混合物に、式（Ｉ－５２－ｈ）で表される塩６．７０部を添加し、２３℃で１時間撹拌した後、セライト７．２部を添加撹拌後、ろ過した。回収されたろ液を濃縮した後、クロロホルム１４０部及び１．５％酢酸水溶液２５部を仕込み、２３℃で３０分間攪拌した後、分液することにより有機層を回収した。この洗浄の操作を２回行った。回収された有機層に、イオン交換水３５部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。回収された有機層に、１％アンモニア水溶液２０部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。この洗浄の操作を２回行った。回収された有機層に、イオン交換水３５部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を４回行った。得られた有機層を濃縮した後、クロロホルム１６部及びｎ－ヘプタン１３０部を添加撹拌後、ろ過することにより、式（Ｉ－５２）で表される塩７．５８部を得た。 Example 1: Synthesis of salt represented by the formula (I-52)

After adding 5 parts of the compound represented by the formula (I-52-a) and 50 parts of acetonitrile and stirring at 23 ° C. for 30 minutes, 4.59 parts of the compound represented by the formula (I-52-b) was added. The mixture was added, and the mixture was refluxed and stirred at 85 ° C. for 15 minutes. A compound represented by the formula (I-52-d) is added to the obtained reaction product by adding 16.50 parts of the compound represented by the formula (I-52-c) and reflux-concentrating at 85 ° C. A solution containing the above was obtained. 33 parts of chloroform and 56 parts of a 5% hydrochloric acid aqueous solution were added to a solution containing the compound represented by the formula (I-52-d), stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. 100 parts of ion-exchanged water was charged into the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to recover the organic layer. This washing operation was performed twice. After concentrating the obtained organic layer, 11.76 parts of the compound represented by the formula (I-52-e) and 0.08 part of sulfuric acid were added to the concentrated residue, and the mixture was stirred at 70 ° C. for 3 hours and then 23. Cooled to ° C. 78 parts of a 1M aqueous sodium hydroxide solution was charged into the obtained reaction mixture containing the compound represented by the formula (I-52-f), and the mixture was stirred at 23 ° C. for 3 hours, and then 68 parts of a 5% aqueous hydrochloric acid solution was charged. The mixture was stirred at 23 ° C. for 30 minutes. 135 parts of chloroform and 40 parts of ion-exchanged water were added to the obtained reaction mixture, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to recover the organic layer. This washing operation was performed three times. By concentrating the obtained organic layer, 5.97 parts of the compound represented by the formula (I-52-g) was obtained.

After adding 5 parts of the compound represented by the formula (I-52-g) and 100 parts of methanol and stirring at 23 ° C. for 30 minutes, 1.39 parts of silver oxide was added and the mixture was stirred at 23 ° C. for 3 hours. To the obtained mixture, 6.70 parts of a salt represented by the formula (I-52-h) was added, and the mixture was stirred at 23 ° C. for 1 hour, and 7.2 parts of Celite was added and stirred, and then filtered. After concentrating the recovered filtrate, 140 parts of chloroform and 25 parts of a 1.5% acetic acid aqueous solution were charged, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to recover the organic layer. This washing operation was performed twice. 35 parts of ion-exchanged water was charged into the recovered organic layer, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. 20 parts of a 1% aqueous ammonia solution was charged into the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to recover the organic layer. This washing operation was performed twice. 35 parts of ion-exchanged water was charged into the recovered organic layer, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed four times. After concentrating the obtained organic layer, 16 parts of chloroform and 130 parts of n-heptane were added, stirred, and then filtered to obtain 7.58 parts of a salt represented by the formula (I-52).

MS (ESI (+) Electrospray): M ⁺ 431.3
MS (ESI (-) Electrospray): M ^- 403.3

式（Ｉ－５２－ａ）で表される化合物５部及びアセトニトリル５０部を添加し、２３℃で３０分間撹拌した後、式（Ｉ－５２－ｂ）で表される化合物４．５９部を添加し、８５℃で、１５分間還流撹拌した。得られた反応物に、式（Ｉ－５２－ｃ）で表される化合物１６．５０部を添加し、８５℃で還流濃縮することにより、式（Ｉ－５２－ｄ）で表される化合物を含む溶液を得た。式（Ｉ－５２－ｄ）で表される化合物を含む溶液に、クロロホルム３３部及び５％塩酸水溶液５６部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。回収された有機層に、イオン交換水１００部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を２回行った。得られた有機層を濃縮した後、濃縮残に、式（Ｉ－５１－ｅ）で表される化合物１７．１２部、アセトニトリル５０部及び硫酸０．０８部を仕込み、７０℃で３時間撹拌した後、２３℃まで冷却した。得られた式（Ｉ－５１－ｆ）で表される化合物を含む反応混合物に、１Ｍ水酸化ナトリウム水溶液７８部を仕込み、２３℃で３時間撹拌した後、５％塩酸水溶液６８部を仕込み、２３℃で３０分間攪拌した。得られた反応混合物に、クロロホルム１３５部及びイオン交換水４０部を仕込み、２３℃で３０分間攪拌した後、分液することにより有機層を回収した。この水洗の操作を３回行った。得られた有機層を濃縮することにより、式（Ｉ－５１－ｇ）で表される化合物７．１２部を得た。

式（Ｉ－５１－ｇ）で表される化合物６．２９部及びメタノール１００部を添加し、２３℃で３０分間撹拌した後、酸化銀１．３９部を添加し、２３℃で３時間撹拌した。得られた混合物に、式（Ｉ－５２－ｈ）で表される塩６．７０部を添加し、２３℃で１時間撹拌した後、セライト７．２部を添加撹拌後、ろ過した。回収されたろ液を濃縮した後、クロロホルム１４０部及び１．５％酢酸水溶液２５部を仕込み、２３℃で３０分間攪拌した後、分液することにより有機層を回収した。この洗浄の操作を２回行った。回収された有機層に、イオン交換水３５部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。回収された有機層に、１％アンモニア水溶液２０部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。この洗浄の操作を２回行った。回収された有機層に、イオン交換水３５部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を４回行った。得られた有機層を濃縮した後、クロロホルム１０部及びｎ－ヘプタン１５０部を添加撹拌後、ろ過することにより、式（Ｉ－５１）で表される塩８．８２部を得た。 Example 2: Synthesis of salt represented by the formula (I-51)

After adding 5 parts of the compound represented by the formula (I-52-a) and 50 parts of acetonitrile and stirring at 23 ° C. for 30 minutes, 4.59 parts of the compound represented by the formula (I-52-b) was added. The mixture was added, and the mixture was refluxed and stirred at 85 ° C. for 15 minutes. A compound represented by the formula (I-52-d) is added to the obtained reaction product by adding 16.50 parts of the compound represented by the formula (I-52-c) and reflux-concentrating at 85 ° C. A solution containing the above was obtained. 33 parts of chloroform and 56 parts of a 5% hydrochloric acid aqueous solution were added to a solution containing the compound represented by the formula (I-52-d), stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. 100 parts of ion-exchanged water was charged into the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to recover the organic layer. This washing operation was performed twice. After concentrating the obtained organic layer, 17.12 parts of the compound represented by the formula (I-51-e), 50 parts of acetonitrile and 0.08 part of sulfuric acid are added to the concentrated residue and stirred at 70 ° C. for 3 hours. After that, it was cooled to 23 ° C. 78 parts of a 1M aqueous sodium hydroxide solution was charged into the obtained reaction mixture containing the compound represented by the formula (I-51-f), and the mixture was stirred at 23 ° C. for 3 hours, and then 68 parts of a 5% aqueous hydrochloric acid solution was charged. The mixture was stirred at 23 ° C. for 30 minutes. 135 parts of chloroform and 40 parts of ion-exchanged water were added to the obtained reaction mixture, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to recover the organic layer. This washing operation was performed three times. By concentrating the obtained organic layer, 7.12 parts of the compound represented by the formula (I-51-g) was obtained.

6.29 parts of the compound represented by the formula (I-51-g) and 100 parts of methanol were added and stirred at 23 ° C. for 30 minutes, then 1.39 parts of silver oxide was added and stirred at 23 ° C. for 3 hours. did. To the obtained mixture, 6.70 parts of a salt represented by the formula (I-52-h) was added, and the mixture was stirred at 23 ° C. for 1 hour, and 7.2 parts of Celite was added and stirred, and then filtered. After concentrating the recovered filtrate, 140 parts of chloroform and 25 parts of a 1.5% acetic acid aqueous solution were charged, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to recover the organic layer. This washing operation was performed twice. 35 parts of ion-exchanged water was charged into the recovered organic layer, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. 20 parts of a 1% aqueous ammonia solution was charged into the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to recover the organic layer. This washing operation was performed twice. 35 parts of ion-exchanged water was charged into the recovered organic layer, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed four times. After concentrating the obtained organic layer, 10 parts of chloroform and 150 parts of n-heptane were added, stirred, and then filtered to obtain 8.82 parts of a salt represented by the formula (I-51).

MS (ESI (+) Electrospray): M ⁺ 431.3
MS (ESI (-) Electrospray): M ^- 507.4

式（Ｉ－９７－ｄ）で表される化合物４．０２部及びアセトニトリル２０部を仕込み、２３℃で３０分間攪拌した後、式（Ｉ－５２－ｅ）で表される化合物１１．７６部及び硫酸０．０８部を仕込み、７０℃で３時間撹拌した後、２３℃まで冷却した。得られた式（Ｉ－９７－ｆ）で表される化合物を含む反応混合物に、１Ｍ水酸化ナトリウム水溶液７８部を仕込み、２３℃で３時間撹拌した後、５％塩酸水溶液６８部を仕込み、２３℃で３０分間攪拌した。得られた反応混合物に、クロロホルム１５０部及びイオン交換水４０部を仕込み、２３℃で３０分間攪拌した後、分液することにより有機層を回収した。この水洗の操作を３回行った。得られた有機層を濃縮することにより、式（Ｉ－９７－ｇ）で表される化合物３．８２部を得た。

式（Ｉ－９７－ｇ）で表される化合物２．１８部及びメタノール１００部を添加し、２３℃で３０分間撹拌した後、酸化銀０．７０部を添加し、２３℃で３時間撹拌した。得られた混合物に、式（Ｉ－５２－ｈ）で表される塩３．３５部を添加し、２３℃で１時間撹拌した後、セライト３．６部を添加撹拌後、ろ過した。回収されたろ液を濃縮した後、クロロホルム７０部及び１．５％酢酸水溶液１３部を仕込み、２３℃で３０分間攪拌した後、分液することにより有機層を回収した。この洗浄の操作を２回行った。回収された有機層に、イオン交換水２０部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。回収された有機層に、１％アンモニア水溶液１０部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。この洗浄の操作を２回行った。回収された有機層に、イオン交換水２０部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を４回行った。得られた有機層を濃縮した後、ｎ－ヘプタン１００部を添加撹拌後、ろ過することにより、式（Ｉ－９７）で表される塩２．１２部を得た。 Example 3: Synthesis of salt represented by formula (I-97)

4.02 parts of the compound represented by the formula (I-97-d) and 20 parts of acetonitrile were charged, stirred at 23 ° C. for 30 minutes, and then 11.76 parts of the compound represented by the formula (I-52-e). And 0.08 part of sulfuric acid was charged, stirred at 70 ° C. for 3 hours, and then cooled to 23 ° C. 78 parts of a 1M aqueous sodium hydroxide solution was charged into the obtained reaction mixture containing the compound represented by the formula (I-97-f), and the mixture was stirred at 23 ° C. for 3 hours, and then 68 parts of a 5% aqueous hydrochloric acid solution was charged. The mixture was stirred at 23 ° C. for 30 minutes. 150 parts of chloroform and 40 parts of ion-exchanged water were added to the obtained reaction mixture, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to recover the organic layer. This washing operation was performed three times. By concentrating the obtained organic layer, 3.82 parts of the compound represented by the formula (I-97-g) was obtained.

2.18 parts of the compound represented by the formula (I-97-g) and 100 parts of methanol are added, and the mixture is stirred at 23 ° C. for 30 minutes, 0.70 parts of silver oxide is added, and the mixture is stirred at 23 ° C. for 3 hours. did. To the obtained mixture, 3.35 parts of a salt represented by the formula (I-52-h) was added, and the mixture was stirred at 23 ° C. for 1 hour, and then 3.6 parts of Celite was added and stirred, and then filtered. After concentrating the recovered filtrate, 70 parts of chloroform and 13 parts of a 1.5% acetic acid aqueous solution were charged, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to recover the organic layer. This washing operation was performed twice. 20 parts of ion-exchanged water was charged into the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to recover the organic layer. The organic layer was recovered by charging 10 parts of a 1% aqueous ammonia solution into the recovered organic layer, stirring at 23 ° C. for 30 minutes, and separating the liquids. This washing operation was performed twice. 20 parts of ion-exchanged water was charged into the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to recover the organic layer. This washing operation was performed four times. After concentrating the obtained organic layer, 100 parts of n-heptane was added, stirred, and then filtered to obtain 2.12 parts of a salt represented by the formula (I-97).

MS (ESI (+) Electrospray): M ⁺ 431.3
MS (ESI (-) Electrospray): M ^- 351.3.

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

Synthesis Example 1: Synthesis of resin A1 As a monomer, a monomer (a1-1-3), a monomer (a1-2-5), a monomer (a2-1-3) and a monomer (a3-4-2) are used. The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-4-2)] is 45: 14: 2.5: 38. The mixture was mixed so as to have a value of 5, and propylene glycol monomethyl ether acetate 1.5% by mass of the total amount of the monomers was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1 mol% and 3 mol%, respectively, based on the total amount of monomers, and these were heated at 73 ° C. for about 5 hours. did. 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 dissolved again in propylene glycol monomethyl ether acetate, and the obtained solution is poured into a methanol / water mixed solvent to precipitate the resin, and the resin is filtered. A resin A1 having a molecular weight of 7.6 × 10 ³ was obtained in a yield of 68%. This resin A1 has the following structural units.

Synthesis Example 2: Synthesis of resin X1 A monomer (a5-1-1) and a monomer (a4-0-12) are used as the monomer, and the molar ratio thereof [monomer (a5-1-1): monomer (a4-0-). 12)] was mixed so that the ratio was 50:50, and methyl isobutyl ketone 1.2% by mass of the total amount of the monomers was added to prepare a solution. Azobis (2,4-dimethylvaleronitrile) as an initiator was added to this solution in an amount of 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of a mixed methanol / water solvent to precipitate a resin, and the resin was filtered to obtain a resin X1 having a weight average molecular weight of 1.0 × 10 ⁴ in a yield of 91%. This resin X1 has the following structural units.

<Preparation of resist composition>
As shown in Table 2, each of the following components was mixed, and the obtained mixture was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

＜カルボン酸塩（Ｉ）＞
Ｉ－５１：式（Ｉ－５１）で表される塩
Ｉ－５２：式（Ｉ－５２）で表される塩
Ｉ－９７：式（Ｉ－９７）で表される塩
ＩＸ－１：特開２０１４－８８３６７号公報の実施例に従って合成

＜化合物（Ｄ）＞
Ｄ１：（東京化成工業（株）製）

＜溶剤＞
プロピレングリコールモノメチルエーテルアセテート ２６５部
プロピレングリコールモノメチルエーテル ２０部
２－ヘプタノン ２０部
γ－ブチロラクトン ３．５部 <Resin>
A1, X1: Resin A1, Resin X1
<Acid generator (B)>
B1-21: Salt represented by the formula (B1-21) (synthesized according to an example of JP2012-224611A)
B1-22: Salt represented by the formula (B1-22) (synthesized according to an example of JP2012-224611A)

<Carboxylate (I)>
I-51: Salt represented by formula (I-51) I-52: Salt represented by formula (I-52) I-97: Salt represented by formula (I-97) IX-1: Special Synthesized according to the examples of Japanese Patent Publication No. 2014-88367

<Compound (D)>
D1: (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Solvent>
Propylene Glycol Monomethyl Ether Acetate 265 Parts Propylene Glycol Monomethyl Ether 20 Parts 2-Heptanone 20 Parts γ-Butyrolactone 3.5 Parts

<Manufacturing of resist pattern and its evaluation>
An organic antireflection film composition (ARC-29; manufactured by Nissan Chemical Industries, Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to cause organic reflection on the wafer with a film thickness of 78 nm. An anti-reflective film was formed. Next, the above resist composition was applied (spin coated) on the organic antireflection film so that the film thickness after drying was 85 nm. After coating, the silicon wafer was prebaked on a direct hot plate at the temperature shown in the “PB” column of Table 2 for 60 seconds to form a composition layer. A contact hole pattern (hole pitch 90 nm) was used on a silicon wafer on which a composition layer was formed with an ArF excimer stepper for immersion exposure (XT: 1900Gi; ASML, NA = 1.35, 3/4 Anal XY polarization). / Using a mask for forming (hole diameter 55 nm), the exposure amount was changed stepwise for exposure. Ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking was performed on a hot plate at the temperature listed in the “PEB” column of Table 2 for 60 seconds. Next, the composition layer on this silicon wafer was developed using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution at 23 ° C. for 20 seconds by the dynamic dispensing method to obtain a negative resist pattern. Manufactured.

In the resist pattern obtained after development, the exposure amount having a hole diameter of 45 nm formed by using the mask was defined as the effective sensitivity.

<Mask error factor (MEF) evaluation>
In terms of effective sensitivity, a resist pattern was formed using a mask having a mask hole diameter (hole diameter of a translucent portion of the mask) of 57 nm, 56 nm, 55 nm, 54 nm, and 53 nm (hole pitch is 90 nm, respectively). The slope of the regression line when the hole diameter of the resist pattern formed (transferred) on the substrate by exposure was plotted on the vertical axis with the mask hole diameter on the horizontal axis was calculated as the MEF value.
Those with a MEF value of 4.6 or less are evaluated as having a good MEF, and are marked with ○.
Those having a MEF value of more than 4.6 were evaluated as having poor MEF and were evaluated as x.
The results are shown in Table 3. The numbers in parentheses indicate the MEF value.

The resist composition containing the carboxylate of the present invention is suitable for fine processing of semiconductors because a resist pattern can be produced with a good mask error factor (MEF).

Claims (7)

Carboxylate represented by the formula (I).

[In formula (I) ,
X ¹ represents a hydrocarbon group having a total carbon number of 1 to 24, and the hydrocarbon group may have one or more hydroxy groups, and -CH _2- contained in the hydrocarbon group is-. It may be replaced with O-, -S-, -CO- or -S (O) _2- .
X ^a and X ^b each independently represent an oxygen atom or a sulfur atom and are bonded to the same carbon atom contained in X ¹ .
L ¹ and L ² each independently represent a single bond or a hydrocarbon group having 1 to 12 total carbon atoms, and -CH _2- contained in the hydrocarbon group is -O-, -S-, -CO. -Or-S (O) ₂ -may be replaced.
R ¹ and R ² each independently represent an alicyclic hydrocarbon group having a total carbon number of 3 to 18 which may have a hydroxy group or a halogen atom , and are contained in the alicyclic hydrocarbon group-CH. _2- may be replaced with -O-, -S-, -CO- or -S (O) _2- .
Z1 ⁺ represents an organic cation represented by the formula (b2-1) . ]

[In equation (b2-1),
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 bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH _2- contained in the ring may be -O-, -S- or. It may be replaced with -CO-. The carboxylate according to claim 1, wherein X ¹ is an alicyclic hydrocarbon group having a total carbon number of 3 to 24. X ¹ is an alkanetriyl group having a total carbon number of 1 to 6, a group represented by the formula (w1-1), a group represented by the formula (w1-2), and a group represented by the formula (w1-3). The carboxylate according to claim 1 , which is a group or a group represented by the formula (w1-6).

A carboxylic acid generator containing the carboxylic acid salt according to any one of claims 1 to 3. A resist composition containing the carboxylic acid generator according to claim 4, an acid generator other than the carboxylic acid generator, and a resin having an acid unstable group. The resist composition according to claim 5, which contains a salt that generates an acid having a weaker acidity than an acid generated from an acid generator other than the carboxylic acid generator. (1) A step of applying the resist composition according to claim 5 or 6 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.