JP6863155B2 - Method for manufacturing resin, resist composition and resist pattern - Google Patents

Description

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

Patent Document 1 describes a resist composition containing a resin composed of the following structural units.

JP-A-2009-42748

In the resist pattern formed from the resist composition containing the above resin, the mask error factor (MEF) may not always be satisfactory.

［式（Ｉ）中、Ａ^１は、単結合又は炭素数１〜１８の２価の炭化水素基を表す。
Ａ^２及びＡ^３は、それぞれ独立に、炭素数１〜１８の２価の炭化水素基を表す。
Ｒ^１及びＲ^２は、それぞれ独立に、炭素数１〜６の飽和炭化水素基を表す。
Ｒ^３及びＲ^４は、それぞれ独立に、水素原子又は炭素数１〜６の飽和炭化水素基を表す。］

［式（ａ３−４）中、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。
Ｌ^ａ７は、単結合、^＊−Ｌ^ａ８−Ｏ−、^＊−Ｌ^ａ８−ＣＯ−Ｏ−、^＊−Ｌ^ａ８−ＣＯ−Ｏ−Ｌ^ａ９−ＣＯ−Ｏ−又は^＊−Ｌ^ａ８−Ｏ−ＣＯ−Ｌ^ａ９−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ｌ^ａ８及びＬ^ａ９は、互いに独立に、炭素数１〜６のアルカンジイル基を表す。
Ｒ^ａ２５は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表す。
ｗ１は、０〜８のいずれかの整数を表す。ｗ１が２以上のとき、複数のＲ^ａ２５は互いに同一であってもよく、異なってもよい。］
［２］Ａ^２及びＡ^３が、それぞれ独立して、メチレン基又はエチレン基である［１］に記載の樹脂。
［３］Ａ^１が、炭素数１〜８のアルカンジイル基である［１］又は［２］に記載の樹脂。
［４］さらに、酸不安定基を有する構造単位を含有する［１］〜［３］のいずれかに記載の樹脂。
［５］［１］〜［４］のいずれかに記載の樹脂及び酸発生剤を含有するレジスト組成物。
［６］さらに、フッ素原子を有する構造単位を含む樹脂を含有する［５］に記載のレジスト組成物。
［７］酸発生剤から発生する酸よりも酸性度の弱い酸を発生する塩をさらに含有する［５］又は［６］のいずれか記載のレジスト組成物。
［８］（１）［５］〜［７］のいずれかに記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層に露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程、
を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A resin containing a structural unit represented by the formula (I) and a structural unit represented by the formula (a3-4).

[In formula (I), A ¹ represents a single bond or a divalent hydrocarbon group having 1 to 18 carbon atoms.
A ² and A ³ each independently represent a divalent hydrocarbon group having 1 to 18 carbon atoms.
R ¹ and R ² each independently represent a saturated hydrocarbon group having 1 to 6 carbon atoms.
R ³ and R ⁴ each independently represent a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. ]

Wherein ^{(a3-4), R a24} represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
L ^a7 is a single bond, ^* -L ^a8- O-, ^* -L ^a8- CO-O-, ^* -L ^a8- CO-O-L ^a9- CO-O- or ^* -L ^a8- O-CO. Represents −L ^a9 −O−.
* Represents a bond with -O-.
^La8 and ^La9 represent an alkanediyl group having 1 to 6 carbon atoms independently of each other.
^Ra25 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
w1 represents any integer from 0 to 8. When w1 is 2 or more, the plurality of Ra ^25s may be the same or different from each other. ]
[2] The resin according to [1], wherein ^{A 2} and A ^{3 are independently methylene groups or ethylene groups.}
[3] The resin according to [1] or [2], wherein ^{A 1 is an alkanediyl group having 1 to 8 carbon atoms.}
[4] The resin according to any one of [1] to [3], which further contains a structural unit having an acid unstable group.
[5] A resist composition containing the resin and acid generator according to any one of [1] to [4].
[6] The resist composition according to [5], which further contains a resin containing a structural unit having a fluorine atom.
[7] The resist composition according to any one of [5] and [6], which further contains a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.
[8] (1) A step of applying the resist composition according to any one of [5] to [7] onto a substrate.
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
(4) A step of heating the composition layer after exposure, and (5) A step of developing the composition layer after heating,
A method for producing a resist pattern including.

By using the resist composition using the resin of the present invention, a resist pattern can be produced with a good mask error factor (MEF).

As used herein, the term "(meth) acrylate" means "at least one of acrylate and methacrylate," respectively. Notations such as "(meth) acrylic acid" and "(meth) acryloyl" have the same meaning.
Unless otherwise specified, "aliphatic hydrocarbon groups" are carbonized into linear and branched hydrocarbon groups, and "aliphatic hydrocarbon groups" are carbonized into cyclic hydrocarbon groups and / or cyclic hydrocarbon groups. It means a group to which a hydrogen group is bonded. The "aromatic hydrocarbon group" also includes a group in which a hydrocarbon group is bonded to an aromatic ring. 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.

〔resin〕
The resin of the present invention has a structural unit represented by the formula (I) (hereinafter, may be referred to as a structural unit (I)) and a structural unit represented by the formula (a3-4) (hereinafter, “structural unit (a3)”. -4) ”(may be referred to as“ resin (A) ”hereinafter.).

［式（Ｉ）中、
Ａ^１は、単結合又は炭素数１〜１８の２価の炭化水素基を表す。
Ａ^２及びＡ^３は、それぞれ独立に、炭素数１〜１８の２価の炭化水素基を表す。
Ｒ^１及びＲ^２は、それぞれ独立に、炭素数１〜６の飽和炭化水素基を表す。
Ｒ^３及びＲ^４は、それぞれ独立に、水素原子又は炭素数１〜６の飽和炭化水素基を表す。］ <Structural unit (I)>

[In formula (I),
A ¹ represents a single bond or a divalent hydrocarbon group having 1 to 18 carbon atoms.
A ² and A ³ each independently represent a divalent hydrocarbon group having 1 to 18 carbon atoms.
R ¹ and R ² each independently represent a saturated hydrocarbon group having 1 to 6 carbon atoms.
R ³ and R ⁴ each independently represent a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. ]

Examples of the divalent hydrocarbon group having 1 to 18 carbon atoms represented by A ¹ , A ² and A ³ include an alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and the like. Examples include aromatic hydrocarbon groups, and a combination of two or more of these groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 , 7-Diyl Group, Octane-1,8-Diyl Group, Nonan-1,9-Diyl Group, Decane-1,10-Diyl Group, Undecane-1,11-Diyl Group, Dodecane-1,12-Diyl Group Linear alkanediyl groups such as;
Ethan-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, hexane-2,5-diyl group, 2-methyl- A branched alkanediyl group such as 5-methylhexane-2,5-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. Group;
Phenylene group, naphthylene group, anthrylene group, p-methylphenylene group, p-tert-butylphenylene group, p-adamantylphenylene group, trill group, xylylene group, cumenylene group, mesitylene group, biphenylene group, phenanthrylene group, 2,6 Examples thereof include an aromatic hydrocarbon group such as a-diethylphenylene group and 2-methyl-6-ethylphenylene.

A ¹ is preferably a monocyclic divalent alicyclic saturated hydrocarbon group or an alkanediyl group having 1 to 8 carbon atoms, and is preferably a cycloalkanediyl group or an alkanediyl group having 1 to 4 carbon atoms. More preferably, it is more preferably a cycloalkanediyl group.
The A ² and A ³ are each independently preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably a methylene group or an ethylene group, and further preferably a methylene group.

Saturated hydrocarbon groups having 1 to 6 carbon atoms represented by R ¹ , R ² , R ³ and R ⁴ include methyl group, ethyl group, propyl group, butyl group, isobutyl group, sec-butyl group and tert-. Examples thereof include an alkyl group such as a butyl group, a pentyl group and a hexyl group; a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group; and a group formed by combining these.
R ¹ , R ² , R ³ and R ⁴ are each independently preferably a methyl group or an ethyl group, and more preferably a methyl group.

Examples of the structural unit (I) include the structural units described below. The structural unit (I) is preferably a structural unit (I-1) to a structural unit (I-6).

［式（Ｉ０）中、Ａ^１、Ａ^２、Ａ^３、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４は、それぞれ、上記と同じ意味を表す。］
化合物（Ｉ０）は、下記式で表される化合物等が挙げられる。

The structural unit (I) is derived from the compound represented by the formula (I0) (hereinafter, may be referred to as compound (I0)).

[In formula (I0), A ¹ , A ² , A ³ , R ¹ , R ² , R ³ and R ⁴ have the same meanings as described above, respectively. ]
Examples of the compound (I0) include compounds represented by the following formulas.

The content of the structural unit (I) is usually 0.1 to 50 mol%, preferably 1 to 30 mol%, and more preferably 2 to 10 mol% with respect to all the monomers in the resin (A). It is more preferably 2 to 6 mol%.

Compound (I0) can be produced by reacting the compound represented by the formula (Ia) in a solvent under a base catalyst.

[In the formula, R ¹ , R ² , R ³ , R ⁴ , A ¹ , A ² and A ³ have the same meanings as above. ]

Examples of the base catalyst include sodium hydroxide and the like.
Examples of the solvent include methanol and the like.

The compound represented by the formula (Ia) is produced by reacting the compound represented by the formula (Ib) with the compound represented by the formula (Ic) in a solvent. Can be done.

Examples of the solvent include dimethylformamide and the like.

The compounds represented by the formula (Ib) are the compound represented by the formula (Id), the compound represented by the formula (I-e1), and the compound represented by the formula (I-e2). Can be produced by reacting with and in a solvent in the presence of a base catalyst.

Examples of the base catalyst include pyridine, N-methylpyrrolidine and the like.
Examples of the solvent include toluene, tetrahydrofuran and the like.
Examples of the compound represented by the formula (Id) include compounds represented by the following.

Examples of the compound represented by the formula (I-e1) and the formula (I-e2) include compounds represented by the following.

［式（ａ３−４）中、
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。
Ｌ^ａ７は、単結合、^＊−Ｌ^ａ８−Ｏ−、^＊−Ｌ^ａ８−ＣＯ−Ｏ−、^＊−Ｌ^ａ８−ＣＯ−Ｏ−Ｌ^ａ９−ＣＯ−Ｏ−又は^＊−Ｌ^ａ８−Ｏ−ＣＯ−Ｌ^ａ９−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ｌ^ａ８及びＬ^ａ９は、互いに独立に、炭素数１〜６のアルカンジイル基を表す。
Ｒ^ａ２５は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表す。
ｗ１は、０〜８のいずれかの整数を表す。ｗ１が２以上のとき、複数のＲ^ａ２５は互いに同一であってもよく、異なってもよい。］ <Structural unit (a3-4)>

[In equation (a3-4),
^Ra24 represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom or a halogen atom which may have a halogen atom.
L ^a7 is a single bond, ^* -L ^a8- O-, ^* -L ^a8- CO-O-, ^* -L ^a8- CO-O-L ^a9- CO-O- or ^* -L ^a8- O-CO. Represents −L ^a9 −O−.
* Represents a bond with -O-.
^La8 and ^La9 represent an alkanediyl group having 1 to 6 carbon atoms independently of each other.
^Ra25 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
w1 represents any integer from 0 to 8. When w1 is 2 or more, the plurality of Ra ^25s may be the same or different from each other. ]

Examples of the aliphatic hydrocarbon group having 1 to 4 carbon atoms represented by R ^a25 include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group and the like. ..
^{Examples of the halogen atom represented by Ra24} include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
^Examples of the alkyl group represented by R a24 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group and an n-hexyl group. However, an alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.
^{Examples of the alkyl group having a halogen atom represented by Ra24} include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. Examples thereof include a group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.
^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.

（式中、Ｒ^ａ２４、Ｌ^ａ７は、上記と同じ意味を表す。） The ^{alkanediyl group represented by La8} and ^La9 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, and a pentan-. 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 Examples thereof include -1,4-diyl group and 2-methylbutane-1,4-diyl group.
L ^a7 is preferably a single bond or ^* -L ^a8- CO-O-, more preferably a single bond, -CH _2- CO-O- or -C ₂ H _4- CO-O-.
The formula (a3-4) is particularly preferably the formula (a3-4)'.

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

The structural unit (a3-4), include structural units in which a methyl group is replaced by a hydrogen atom corresponding to R ^a24 in the following structural units and the following structural units.

The content of the structural unit (a3-4) is usually 5 to 95 mol%, preferably 10 to 95 mol%, and more preferably 15 to 90 mol% with respect to the total structural unit of the resin (A). %.
The resin (A) may contain two or more types of structural units (a3-4).

The resin (A) may contain two or more types of structural units (I).
The resin (A) preferably further has a structural unit having an acid unstable group (hereinafter, may be referred to as "structural unit (a1)"). Here, the "acid-unstable group" means a group having a leaving group, and the leaving group is removed by contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group). ..

［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。
ｎａは、０又は１を表す。
＊は酸素原子又は硫黄原子との結合手を表す。］

［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メチレン基は、酸素原子又は硫黄原子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。
＊酸素原子又は硫黄原子とのは結合手を表す。］ <Structural unit (a1)>
The structural unit (a1) is derived from a monomer having no halogen atom and having an acid unstable group (hereinafter, may be referred to as “monomer (a1)”).
In the resin (A), the acid unstable group contained in the structural unit (a1) preferably contains a group represented by the following formula (1) and / or a group represented by the formula (2).

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

[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 to which they are bonded, and the hydrocarbon group and the divalent heterocyclic group. The methylene group contained in may be replaced with an oxygen atom or a sulfur atom.
X represents an oxygen atom or a sulfur atom.
* Oxygen atom or sulfur atom represents a bond. ]

アルキル基と脂環式炭化水素基とを組み合わせた基としては、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基、シクロヘキシルメチル基、アダマンチルメチル基、ノルボルニルエチル基等が挙げられる。
ｎａは、好ましくは０である。 ^Examples of the alkyl group of R ^{a1 to} R a3 include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group and the like.
The alicyclic hydrocarbon groups of R ^{a1 to} R ^a3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups (* indicates a bond). The alicyclic hydrocarbon groups of R ^{a1 to} R ^a3 have 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, a norbornylethyl group and the like. ..
na is preferably 0.

^{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-.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (a group in which R ^{a1 to} R ^a3 are alkyl groups in the formula (1), preferably a tert-butoxycarbonyl group), 2-. Alkyl adamantan-2-yloxycarbonyl group (in formula (1), R ^a1 , R ^a2 and the carbon atom to which they are bonded form an adamantyl group, and R ^a3 is an alkyl group) and 1- (adamantan-). 1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups and R ^a3 is an adamantyl group) and the like.

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。 Examples of the hydrocarbon group R ^{a1 '~R a3',} an alkyl group, an alicyclic hydrocarbon group, and a group formed by combining an aromatic hydrocarbon group and thereof.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same as above.
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, a p-adamantylphenyl group, a trill group, a xsilyl group, a cumenyl group, a mesityl group and a biphenyl group. Examples thereof include an aryl group such as a group, a phenanthryl group, a 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl.
^{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', it is preferable that at least one is a hydrogen atom.

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

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

Among the (meth) acrylic monomers having an acid unstable group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. If a resin (A) having a structural unit derived from a 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.

The structural unit derived from the (meth) acrylic monomer having a group represented by the formula (1) is preferably a structural unit represented by the formula (a1-0) (hereinafter referred to as a structural unit (a1-0)). (In some cases), a structural unit represented by the formula (a1-1) (hereinafter, may be referred to as a structural unit (a1-1)) or a structural unit represented by the formula (a1-2) (hereinafter, referred to as a structural unit). It may be referred to as a structural unit (a1-2)). These may be used alone or in combination of two or more.

［式（ａ１−０）、式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a01は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k01−ＣＯ−Ｏ−を表し、ｋ０１は１〜７のいずれかの整数を表し、＊はカルボニル基との結合手を表す。
Ｒ^a01は、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。
Ｌ^a1及びＬ^a2は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_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^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組み合わ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。］

[In the formula (a1-0), the formula (a1-1) and the formula (a1-2),
L ^a01 represents an oxygen atom or _{^{* -O- (CH 2) k01 -CO}} -O- the stands, k01 represents an integer of 1-7, * represents a bond to a carbonyl group.
R ^a01 represents 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.
^La1 and ^La2 independently represent −O− or ^* −O− (CH ₂ ) _k1 −CO−O−, k1 represents an integer of 1 to 7, and * represents −CO−. Represents a bond with.
R ^a4 and R ^a5 independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 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. ]

^La01 is preferably an oxygen atom or ^* -O- (CH ₂ ) _k01- CO-O-, and more preferably an oxygen atom. k01 is preferably an integer of 1 to 4, more preferably 1.
Examples of the alkyl group of R ^a02 , R ^a03 and R ^a04 , the alicyclic hydrocarbon group and the group combining these groups include the same groups as those mentioned in ^{R a1 to} R ^{a3 of the formula (1).}
The alkyl groups of R ^a02 , R ^a03 and R ^a04 preferably have 6 or less carbon atoms.
The alicyclic hydrocarbon groups of R ^a02 , R ^a03 and R ^a04 preferably have 3 to 8 carbon atoms, and 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 with these alkyl groups and the alicyclic hydrocarbon group. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group and the like.
R ^a02 and R ^a03 are each independently, preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group or an ethyl group.
^Ra04 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.

^La1 and ^La2 are independent of each other, preferably −O− or ^* −O− (CH ₂ ) _{k1 ′} −CO−O−, and more preferably −O−. k1'is an integer of any of 1 to 4, preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
The alkyl groups of R ^a6 and R ^a7 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group and n-hexyl group. Examples thereof include an n-heptyl group, a 2-ethylhexyl group and an n-octyl group.
The alicyclic hydrocarbon groups of R ^a6 and R ^a7 may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group and a cyclopentyl group. , Cycloalkyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group, cyclodecyl group and the like. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, and a norbornyl group. Examples thereof include a group, a methylnorbornyl group and an isobornyl group.
Examples of the group formed by combining the alkyl group of R ^a6 and R ^a7 and the alicyclic hydrocarbon group include an aralkyl group, and a benzyl group, a phenethyl group and the like.
The alkyl groups of R ^a6 and R ^a7 have preferably 6 or less carbon atoms, more preferably 1 to 3 carbon atoms, and further preferably 2 or 3 carbon atoms.
The alicyclic hydrocarbon groups of R ^a6 and R ^a7 have preferably 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms.
m1 is preferably an integer of 0 to 3, 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 of the formulas (a1-0-1) to (a1-0-12) is preferable, and the structural units (a1-0-1) to The structural unit represented by any of the formulas (a1-0-10) is more preferable.

In the above structural units, structural units in which a methyl group is replaced by a hydrogen atom corresponding to R ^a01 may be mentioned as specific examples of the structural units (a1-0).

Examples of the structural unit (a1-1) include structural units derived from the monomers described in JP-A-2010-204646. It is preferably a structural unit represented by the formulas (a1-1-1) to (a1-1-8).

The structural unit (a1-2) is preferably a structural unit represented by any of the formulas (a1-2-1) to (a1-2-12), and more preferably the formula (a1-2). -3), a structural unit represented by the formula (a1-2-4), the formula (a1-2-9) or the formula (a1-2-10), and more preferably the formula (a1-2-3). ), Formula (a1-2-5), formula (a1-2-9) or formula (a1-2-11), more preferably formula (a1-2-5) or formula. It is a structural unit represented by (a1-2-11).

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 total of units.

［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 having an acid unstable group include a structural unit represented by the formula (a1-5) (hereinafter, may be referred to as “structural unit (a1-5)”).

Wherein (a1-5), R ^a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or * − (CH ₂ ) _h3 −CO−L ⁵⁴ −, h3 represents an integer of 1 to 4, and * represents a bond with ^{L 51.}
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ 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 preferably a fluorine atom. 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 represents a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
It is preferable that one of L ⁵² and L ⁵³ is -O- and the other is -S-.
As s1, 1 is preferable.
As s1', any integer of 0 to 2 is preferable.
As Z ^a1 , a single bond or * -CH _2- CO-O- is preferable.

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

When the resin (A) has a structural unit (a1-5), the content thereof is preferably 1 to 50 mol% with respect to the total of all the structural units of the resin (A), and 3 to 45. It is more preferably mol%, and even more preferably 5-40 mol%.

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

When the resin (A) contains any of the structural units (a1-3-1) to the structural units (a1-3-7), the content thereof is 10 to 10 with respect to all the structural units of the resin (A). 95 mol% is preferable, 15 to 90 mol% is more preferable, and 20 to 85 mol% is further preferable.

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

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

^Examples of the alkyl group in 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 in 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 and a hexyloxy group. 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.
As the hydrocarbon group for R ^a34, R ^a35 and R ^a36, an alkyl group, an alicyclic hydrocarbon group, aromatic hydrocarbon group, and include groups formed by combining these, alkyl groups and alicyclic hydrocarbon groups Examples thereof include groups similar to the alkyl groups and alicyclic hydrocarbon groups in R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7.
The aromatic hydrocarbon group includes a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a trill group, a xsilyl group, a cumenyl group, a mesityl group and a biphenyl group. 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. 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 these groups. Can be mentioned.

In the formula (a1-4), a hydrogen atom is preferable as ^Ra32.
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 aliphatic hydrocarbon group having 3 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms. Alkyl group and alicyclic hydrocarbon group for R ^a36 is preferably unsubstituted. Aromatic hydrocarbon group for R ^a36 is an aromatic ring preferably has an aryloxy group having 6 to 10 carbon atoms.

Examples of the structural unit (a1-4) include a structural unit derived from a monomer described in JP-A-2010-204646. Preferably, hydrogen atom corresponding to ^{R a32} in equation (a1-4-1) represented respectively to Formula (a1-4-8) structural units and structural units (a1-4) is replaced by a methyl group structure Units are mentioned, and more preferably, structural units represented by the formulas (a1-4-1) to (a1-4-5) are mentioned.

When the resin (A) contains structural units (a1-4), the content thereof is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, based on all the structural units of the resin (A). 20-85 mol% is more preferred.

The structural unit (a1) having an acid unstable group in the resin (A) is at least selected from the group consisting of a structural unit (a1-0), a structural unit (a1-1) and a structural unit (a1-2). One or more are preferable, and at least two or more are more preferable, a combination of structural units (a1-1) and structural units (a1-2), combinations of structural units (a1-1) and structural units (a1-0), and structures. A combination of the unit (a1-2) and the structural unit (a1-0), a combination of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2) is more preferable, and the structural unit (a1) A combination of -1) and the structural unit (a1-2) is particularly preferable.

The resin (A) further contains a monomer having no halogen atom and no acid-labile group (hereinafter, may be referred to as “monomer (s)”) and / or another structural unit (t) described later. It may be contained.

<Structural unit (s)>
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid unstable group is preferable. A structure having a hydroxy group and no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a lactone ring and no acid-labile 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 contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.

When the resin (A) has a structural unit (a2) having a phenolic hydroxy group, the content thereof is preferably 5 to 95 mol%, preferably 10 to 80 mol%, based on the total structural units of the resin (A). % Is more preferred, and 15-80 mol% is even more preferred.

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

In equation (a2-1),
^La3 represents −O− or ^* −O− (CH ₂ ) _k2 −CO−O−.
k2 represents any integer from 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 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), L ^a3 is preferably, -O -, - O- (CH 2) f1 -CO-O- and is (wherein f1 is an integer of 1 to 4) , More preferably -O-.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group, and more preferably 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) 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). Yes, more preferably 1 to 35 mol%, still more preferably 2 to 20 mol%.

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 , The structural unit (a2) having a phenolic hydroxy group is preferable. When an ArF excimer laser (193 nm) or the like is used, the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group.
The resin (A) may contain two or more types of structural units (a2).

<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 bridging ring containing a γ-butyrolactone ring or a γ-butyrolactone ring structure can be mentioned.

The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), or the formula (a3-3). One of these may be contained alone, or two or more thereof may be contained.

［式（ａ３−１）中、
Ｌ^a4は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_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。＊はカルボニル基との結合手を表す。
Ｒ^a18は、水素原子又はメチル基を表す。
Ｒ^a21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。ｐ１が２以上のとき、複数のＲ^a21は互いに同一又は相異なる。
式（ａ３−２）中、
Ｌ^a5は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_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。＊はカルボニル基との結合手を表す。
Ｒ^a19は、水素原子又はメチル基を表す。
Ｒ^a22は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表す。
ｑ１は、０〜３のいずれかの整数を表す。ｑ１が２以上のとき、複数のＲ^a22は互いに同一又は相異なる。
式（ａ３−３）中、
Ｌ^a6は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_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。＊はカルボニル基との結合手を表す。
Ｒ^a20は、水素原子又はメチル基を表す。
Ｒ^a23は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表す。
ｒ１は、０〜３のいずれかの整数を表す。ｒ１が２以上のとき、複数のＲ^a23は互いに同一又は相異なる。］

[In equation (a3-1),
^La4 represents −O− or ^* −O− (CH ₂ ) _k3 −CO−O− (k3 is an integer of any of 1 to 7.
) Represents a group. * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents any integer from 0 to 5. When p1 is 2 or more, a plurality of Ra ^21s are the same or different from each other.
In equation (a3-2),
^La5 represents −O− or ^* −O− (CH ₂ ) _k3 −CO−O− (k3 is an integer of any of 1 to 7.
) Represents a group. * Represents a bond with a carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents any integer from 0 to 3. When q1 is 2 or more, a plurality of ^Ra22s are the same or different from each other.
In formula (a3-3),
^La6 represents −O− or ^* −O− (CH ₂ ) _k3 −CO−O− (k3 is an integer of any of 1 to 7.
) Represents a group. * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents any integer from 0 to 3. When r1 is 2 or more, a plurality of ^Ra23s are the same or different from each other. ]

The aliphatic hydrocarbon groups of R ^a21 , R ^a22 and R ^a23 include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group. Can be mentioned.

In the formula (a3-1) ~ formula (a3-3), L ^a4 ~L ^a6 are each independently preferably, -O- or is either an integer k3 is 1 to 4 * -O- (CH ₂ ) _{A group represented by k3-} CO-O-, more preferably -O- and * -O-CH _2- CO-O-, still more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently, preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are independently, preferably an integer of 0 to 2, and more preferably 0 or 1.

Examples of the monomer for deriving the structural unit (a3) include the monomers described in JP-A-2010-204646, the monomers described in JP-A-2000-122294, and the monomers described in JP-A-2012-41274. Can be mentioned. The structural unit (a3) includes formulas (a3-1-1) to (a3-1-4), formulas (a3-2-1) to formulas (a3-2-4), and formulas (a3-3-3). 1) to formula (a3-3-4) are preferable, and formula (a3-1-1), formula (a3-1-2), formula (a3-2-1) and formula (a3-2-3) to The structural unit represented by any of the formula (a3-2-4) is more 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 to 60 mol%.
The content of each of the structural units represented by the formulas (a3-1), (a3-2) and (a3-3) is usually 5 to 60 mol% with respect to the total structural units of the resin (A). It is preferably 5 to 50 mol%, and more preferably 10 to 50 mol%.

<Other structural units (t)>
The resin (A) may contain other structural units (t) as structural units other than the structural unit (a1) and the structural unit (s). As the structural unit (t), a structural unit having a halogen atom in addition to the structural unit (a2) and the structural unit (a3) (hereinafter, sometimes referred to as “structural unit (a4)”) and a non-desorbed hydrocarbon group are used. Examples thereof include structural units having (hereinafter, may be referred to as “structural unit (a5)”).

［式（ａ４−０）中、
Ｒ^５は、水素原子又はメチル基を表す。
Ｌ^５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。
Ｌ^３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５〜１２のペルフルオロシクロアルカンジイル基を表す。
Ｒ^６は、水素原子又はフッ素原子を表す。］ <Structural unit (a4)>
As the halogen atom in the structural unit (a4), a fluorine atom is preferable. 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 ⁵ 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 5 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

Examples of the aliphatic saturated hydrocarbon group of L ^5, include alkanediyl group having 1 to 4 carbon atoms, e.g., methylene group, ethylene group, propane-1,3-diyl, butane-1,4-diyl group Such as linear alkanediyl group, linear alkanediyl group having an alkyl group (among others, methyl group, ethyl group, etc.) side chain, ethane-1,1-diyl group, propane-1,2 Examples thereof include branched alkanediyl groups such as −diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.

The perfluoro alkanediyl group L ^3, difluoromethylene group, a perfluoroalkyl ethylene group, perfluoro-1,1-diyl group, perfluoro-1,3-diyl group, perfluoro-1,2-diyl group, 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.
The perfluorocycloalkanes diyl group L ^3, perfluoro-cyclohexane diyl group, perfluoro cyclopentanediyl group, perfluoro cycloheptane-diyl group, a perfluoroalkyl adamantane-diyl group and the like.

L ⁵ represents preferably a single bond, a methylene group or an ethylene group, more preferably a single bond or a methylene group.
L ³ is preferably a 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 following.

In the above structural unit, a structural unit in ^{which the methyl group corresponding to R 5} is replaced with a hydrogen atom can also be mentioned as a specific example of the structural unit (a4-0).

［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−ｇ１１）で表される基を表す。ただし、Ａ^ａ４１及びＲ^ａ４２のうち少なくとも１つは、置換基としてハロゲン原子（好ましくはフッ素原子）を有する。

〔式（ａ−ｇ１１）中、
ｓは０又は１を表す。
Ａ^a42及びＡ^a44は、それぞれ独立に、置換基を有していてもよい炭素数１〜５の２価の脂肪族炭化水素基を表す。
Ａ^a43は、置換基を有していてもよい炭素数１〜５の２価の脂肪族炭化水素基又は単結合を表す。
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６以下である。〕
ただし、Ａ^a41及びＲ^a42のうち少なくとも一方は、置換基としてハロゲン原子を有する基である。
＊及び＊＊は結合手を表し、＊が−Ｏ−ＣＯ−Ｒ^ａ４２との結合手を表す。］
ｓは０が好ましい。 Examples of the structural unit (a4) include a structural unit represented by the formula (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 (ag11). However, ^{at least one of A a41} and R ^a42 has a halogen atom (preferably a fluorine atom) as a substituent.

[In the formula (ag11),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a divalent aliphatic hydrocarbon group or a single bond having 1 to 5 carbon atoms which may have 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 6 or less.} ]
However, ^{at least one of A a41} and R ^a42 is a group having a halogen atom as a substituent.
* And ** represent a bond, and * represents a bond with -O-CO-R ^a42 . ]
s is preferably 0.

芳香族炭化水素基としては、例えば、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等が挙げられる。 ^Examples of the hydrocarbon group of R a42 include a chain type and a ring type aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. 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, hexadecyl group, pentadecyl group and hexyldecyl group. , Alkyl groups such as heptadecyl group and octadecyl group. Cyclic alicyclic 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 (*). Represents a bond.) And other polycyclic alicyclic hydrocarbon groups can be mentioned.

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.

^As the hydrocarbon group of R a42, a chain type or a ring type aliphatic hydrocarbon group and a group formed by combining these are preferable. These groups may have a carbon-carbon unsaturated bond, but chain and cyclic aliphatic saturated hydrocarbon groups and groups formed by combining them are more preferable.

［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、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。
＊はカルボニル基との結合手を表す。］ ^Examples of the substituent of R a42 include 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 having at least one halogen atom.
* Represents a bond with a carbonyl group. ]

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 carbon. 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。］ The aliphatic hydrocarbon having a group represented by the formula (ag3) is 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 even more preferably a cyclohexyl group or an adamantyl group.

Examples of the group represented by the formula (ag2) include the following groups.

The ^{alkanediyl group of A a41} includes 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 branched alkanediyl groups 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 aliphatic hydrocarbon groups of A a42} , A ^a43 and A ^{a44 in} the group represented by the formula (a-g1) (hereinafter, sometimes referred to as "group (ag1)") include a methylene group and an ethylene group. , Propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group Examples include a group, a 2-methylpropane-1,2-diyl group and the like. Examples of these substituents include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.

^{Examples of the group (ag1) in} which X a42 is an oxygen atom 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 group (ag1) in} which X a42 is a carbonyl group include the following groups.

^{Examples of the group (ag1) in} which X a42 is a carbonyloxy group include the following groups.

^{Examples of the group (ag1) in} which X a42 is an oxycarbonyl group include the following groups.

［式（ａ４−２）中、
Ｒ^ｆ1は、水素原子又はメチル基を表す。
Ａ^ｆ1は、炭素数１〜６のアルカンジイル基を表す。
Ｒ^ｆ2は、フッ素原子を有する炭素数１〜１０の炭化水素基を表す。］ As the structural unit represented by the formula (a4-1), the structural unit represented by the formula (a4-2) is preferable.

[In equation (a4-2),
R ^f1 represents a hydrogen atom or a methyl group.
A ^f1 represents an alkanediyl group having 1 to 6 carbon atoms.
R ^f2 represents a hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom. ]

The ^{alkanediyl group of A f1} 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, and a pentane-1,5-diyl group. , Hexine-1,6-diyl group and other linear alkanediyl groups; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 Examples thereof include branched alkanediyl groups such as −diyl group, 1-methylbutane-1,4-diyl group and 2-methylbutane-1,4-diyl group.

The hydrocarbon group of R ^f2 includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and the aliphatic hydrocarbon group includes a chain type, a cyclic type and a group formed by a combination thereof. As the aliphatic hydrocarbon group, an alkyl group and an alicyclic hydrocarbon group are preferable.
Alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group and 2 -Ethylhexyl group is mentioned.
The alicyclic hydrocarbon group may be either a monocyclic group or a polycyclic group, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and a methylcyclohexyl group. , Cycloalkyl groups such as dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, and a norbornyl group. Examples thereof include a methylnorbornyl group and an isobornyl group.

Examples of the hydrocarbon group having a fluorine atom of R ^f2 include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
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, 2,3,3,4,5-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,5-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.

In the formula (a4-2), A ^f1 is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.
As R ^f2 , an alkyl fluoride group having 1 to 6 carbon atoms is preferable.

Examples of the structural unit (a4-2) include the following structural units.

Examples of the structural unit (a4) include the following structural units.

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 preferable.

［式（ａ５−１）中、
Ｒ⁵¹は、水素原子又はメチル基を表す。
Ｒ⁵²は、炭素数３〜１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる水素原子は炭素数１〜８の脂肪族炭化水素基で置換されていてもよい。但し、Ｌ⁵⁵との結合位置にある炭素原子に結合する水素原子は、炭素数１〜８の脂肪族炭化水素基で置換されない。
Ｌ⁵⁵は、単結合又は炭素数１〜１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］ <Structural unit (a5)>
Examples of the non-eliminating hydrocarbon group contained in the structural unit (a5) include a linear, branched or cyclic hydrocarbon group, and preferably 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 replaced by an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

The alicyclic hydrocarbon group 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.
Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group and a hexyl group. , Alkyl groups such as octyl group and 2-ethylhexyl group.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group.
R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

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

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

In formula (L1-1),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total number of carbon atoms of ^{L x1} and L ^{x2 is 16 or less.}
In formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total number of carbon atoms of ^{L x1} and L ^{x2 is 17 or less.}
In formula (L1-3),
L ^x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
However, the total number of carbon atoms 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 independently of each other.
W ^{x 1} represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total number of carbon atoms 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 ^x5 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 ^{x 1} is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, and more preferably a cyclohexanediyl group or an adamantandiyl group.

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

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

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

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

L ⁵⁵ is preferably a single bond, a methylene group, an ethylene group or a group represented by the formula (L1-1), and more preferably a single bond or a group represented by the formula (L1-1). ..

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). ~ 15 mol% is more preferred.

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.

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and when the resin (A) is produced by using the monomer for inducing these structural units, the compound ( I0) acts as a chain transfer agent. The amount of compound (I0) used is usually 0.1 to 50 mol%, preferably 1 to 30 mol%, more preferably 2 to 10 mol%, based on the total monomers of the resin (A). is there. 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) and 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.

The content of 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.

<Resist composition>
The resist composition of the present invention contains a resin (A) and an acid generator.
The resist composition preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") and a solvent (hereinafter sometimes referred to as "solvent (E)").

<Resin other than resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A). Examples of such a resin include a resin containing a structural unit having a fluorine atom.

As the resin containing a structural unit having a fluorine atom, a resin containing a structural unit (a4) (however, it does not contain the structural unit (I); 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). ..
The resin (X) preferably does not contain the structural unit (a1).
Examples of the structural unit that the resin (X) may further include include a structural unit (a2), a structural unit (a3), 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 resin (X) is contained, the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, and further preferably 1 to 1 to 100 parts by mass with respect to 100 parts by mass of the resin (A). It is 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.

<Acid generator (B)>
As the acid generator (B), either a nonionic type or an ionic type may be used. Examples of nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), and sulfones. (For example, disulfone, 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 Japanese Patent Application Laid-Open No. 63-26653, Japanese Patent Application Laid-Open No. 55-164824, Japanese Patent Application Laid-Open No. 62-69263, Japanese Patent Application Laid-Open No. 63-146038, and Japanese Patent Application Laid-Open No. 63-163452. Kaisho 62-153853, Japanese Patent Application Laid-Open No. 63-146029, US Pat. No. 3,779,778, US Pat. 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. Moreover, you may use the compound produced by the known method. The acid generator (B) may be used in combination of two or more.

［式（Ｂ１）中、
Ｑ^１及びＱ^２は、互いに独立に、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−、−ＳＯ_２−又は−ＣＯ−に置き換わっていてもよい。
Ｚ^＋は、有機カチオンを表す。］ The acid generator (B) is preferably a fluorine-containing acid generator, and more preferably a salt represented by the formula (B1) (hereinafter, may be referred to as “acid generator (B1)”).

[In equation (B1),
Q ¹ and ^{Q 2} independently represents 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 an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a methyl group which may have a substituent or a substituent, and is contained in the alicyclic hydrocarbon group. CH ₂ - is, -O -, - SO ₂ - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]

The perfluoroalkyl group of Q ¹ and Q ^2, a trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, a perfluoro sec- butyl group, perfluoro-tert- butyl group, perfluoropentyl group, and a perfluoro Hexyl groups and the like can be mentioned.
Q ¹ and Q ² are preferably fluorine atoms or trifluoromethyl groups independently of each other, and more preferably 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 of the 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, Decane-1,10-Diyl Group, Undecane-1,11-Diyl Group, Dodecane-1,12-Diyl Group , Tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group. Alcandiyl group;
Ethan-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-} contained 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 the formulas (b1-1) to (b1-3) and the following specific examples, * 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メチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
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メチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
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メチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
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. The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
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. The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
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. The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total number of carbon atoms of ^{L b6} and L ^{b7 is 23 or less.} ]

In formulas (b1-1) to (b1-3), when the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group, the number of carbon atoms before the replacement is the carbon of the saturated hydrocarbon group. Let it be a number.
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. The methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.

The _{group in which -CH 2-} contained in the divalent saturated hydrocarbon group of ^{L b1} is replaced with -O- or -CO- is a group represented by 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 number of carbon atoms 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 number of carbon atoms 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２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２０は、単結合又は炭素数１〜２３の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子はフッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１９及びＬ^ｂ２０の合計炭素数は２３以下である。
式（ｂ１−１０）中、
Ｌ^ｂ２１は、単結合又は炭素数１〜２１の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２２は、単結合又は炭素数１〜２１の２価の飽和炭化水素基を表す。
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２価の飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ２１〜Ｌ^ｂ２３の合計炭素数は２１以下である。
式（ｂ１−１１）中、
Ｌ^ｂ２４は、単結合又は炭素数１〜２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２５は、炭素数１〜２１の２価の飽和炭化水素基を表す。
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２価の飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ２４〜Ｌ^ｂ２６の合計炭素数は２１以下である。］ Examples of 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 divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. May be good. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
However, the total number of carbon atoms 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 divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
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 divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. You may. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
However, the total number of carbon atoms of ^{L b21 to} 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 divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
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 divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. You may. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
^However, the total number of carbon atoms of L b24 ^{~L b26} is 21 or less. ]

In formulas (b1-10) and (b1-11), when the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with an acyloxy group, the number of carbon atoms of the acyloxy group, CO in the ester bond and The number of carbon atoms of the divalent saturated hydrocarbon group including the number of O is used.

Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, an adamantylcarbonyloxy group and the like.
Examples of the acyloxy group having a substituent include an oxoadamantylcarbonyloxy group, a hydroxyadamantylcarbonyloxy group, an oxocyclohexylcarbonyloxy group, a hydroxycyclohexylcarbonyloxy 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.

Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y11) and formulas (Y36) to (Y38).
_{When -CH 2-} contained in the alicyclic hydrocarbon group represented by Y is replaced by -O-, -SO _2- or -CO-, the number may be one or two or more. .. Examples of such a group include groups represented by the formulas (Y12) to (Y35).

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

Examples of the substituent of the methyl group represented by Y include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group 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. It represents a hydrocarbon group. Ja represents an integer of 0 to 4) and the like.
As the substituent of the alicyclic hydrocarbon group represented by Y, an alkyl group having 1 to 12 carbon atoms which may be substituted with a halogen atom, a hydroxy group or a hydroxy group, and an alicyclic group having 3 to 16 carbon atoms A hydrocarbon group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 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 carbide having 6 to 18 carbon atoms. It represents a hydrogen 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 xsilyl group, a cumenyl group and a mesityl group. , Biphenyl group, phenanthryl group, aryl group such as 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl and the like.
Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, a heptyl group, and 2 -Ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group and the like can be mentioned.
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 acyl group include an acetyl group, a propionyl group, a butyryl group and the like.

Examples of Y include the following.

When Y is a methyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated hydrocarbon group at the bonding position with Y It is preferable that −CH ₂₋ is replaced with −O− or −CO−.

Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably an adamantyl group which may have a substituent, and is said to be an alicyclic hydrocarbon. The methylene group constituting the hydrogen group or the adamantyl group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group. 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) "etc. ] Are preferable, and formulas (B1-A-1) to (B1-A-4), formulas (B1-A-9), formulas (B1-A-10), formulas (B1-A-24) to formulas (B1-A-24) to formulas. (B1-A-33), formulas (B1-A-36) to formulas (B1-A-40), formulas (B1-A-47) to formulas (B1-A-55). Anions are more preferred.

Here, R ^{i2 to} R ⁱ⁷ are, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. ^Ri8 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 ⁴ is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Q ¹ and ^{Q 2} are the same 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, equations (B1a-1) to (B1a-3) and equations (B1a-7) to (B1a-16), equations (B1a-18), equations (B1a-19), and equations (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.
^{Z +} in the formula (B1) is preferably a cation represented by any of the formulas (b2-1) to (b2-4) [hereinafter, "cation (b2-1)" or the like according to the formula number. In some cases. ].

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

[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 substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may form a ring together with the sulfur atom to which they are bonded, and -CH _2- contained in the ring may be replaced with -O-, -SO- or -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 form a ring together with the sulfur atom to which they are bonded, and -CH _2- contained in the ring may be replaced with -O-, -SO- or -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 combined to form a ring containing -CH-CO- to which they are bonded, and -CH _2- contained in the ring is -O-, -SO-. Alternatively, it may be replaced with −CO−.
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 -S- or -O-.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represent an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, a plurality of R ^b13s may be the same or different, and when p2 is 2 or more, a plurality of R ^b14s may be the same or different, and when q2 is 2 or more. , A plurality of R ^b15s may be the same or different, and when r2 is 2 or more, a plurality of R ^b16s may be the same or different, and when s2 is 2 or more, a plurality of R ^b17s may be present. It may be the same or different, and when t2 is 2 or more, a plurality of R ^b18s may be the same or different. ]

The aliphatic hydrocarbon group includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group and a 2-ethylhexyl group. Alkyl group of. In particular, ^{the aliphatic hydrocarbon groups of R b9 to} R ^b12 preferably have 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and 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 groups of R b9 to} R ^b12 preferably have 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-alkyladamantan-2-yl group, a methylnorbornyl group and an isobornyl group. The group etc. can be mentioned. In the alicyclic hydrocarbon group in which the hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.

The aromatic hydrocarbon group includes a phenyl group, a tolyl group, a xsilyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a p-cyclohexylphenyl group and a 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, an aliphatic hydrocarbon group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms may be used. preferable.
Examples of the aromatic hydrocarbon group in which the hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group.
Examples of the aliphatic hydrocarbon group in which the hydrogen atom is substituted 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 acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkylcarbonyloxy group include methylcarbonyloxy group, ethylcarbonyloxy group, n-propylcarbonyloxy group, isopropylcarbonyloxy group, n-butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, and the like. Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group and a 2-ethylhexylcarbonyloxy group.

The ^{rings that R b4} and R ^b5 may form with the sulfur atoms to which they are attached are monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. There may be. Examples of this ring include a ring having 3 to 18 carbon atoms, and preferably a ring having 4 to 18 carbon atoms. Examples of the ring containing a sulfur atom include a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and specifically, the following ring.

The ^{ring formed by R b9} and R ^b10 together with the sulfur atom to which they are bonded may be monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. Good. Examples of this ring include a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and examples thereof include a thiolan-1-ium ring (tetrahydrothiophenium ring) and a thian-1-ium. Rings, 1,4-oxatian-4-ium rings and the like can be mentioned.
The ^{ring formed by R b11} and R ^b12 together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of this ring include a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and examples thereof include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring. Be done.

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

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

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

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

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

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

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 30 parts by mass or less, based on 100 parts by mass of the resin (A). (More preferably, 25 parts by mass or less). The resist composition of the present invention may contain one kind of the acid generator (B) alone, or may contain a plurality of kinds.

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

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

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

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

Specifically, 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-,3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine, hexylamine. , Heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, trypentylamine, trihexylamine, Triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine , Ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, Triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino- 3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di (2-pyridyl) ethane, 1,2-di (4) −Pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethane, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyl) Oxy) ethane, di (2-pyridyl) ketone, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicorylamine, bipyridine and the like. , Preferably diisopropylaniline, and particularly preferably 2,6-diisopropylaniline.

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

<Salt that generates acid with weak acidity>
The acidity of a salt that produces an acid that is weaker than the acid generated by the acid generator is indicated by the acid dissociation constant (pKa). The salt that generates an acid having a weaker acidity than the acid generated from the acid generator is a salt in which the pKa of the acid generated from the salt is usually -3 <pKa, preferably -1 <pKa <7. , And more preferably a salt of 0 <pKa <5. Examples of the salt that generates an acid weaker than the acid generated from the acid generator include salts represented by the following formulas, and JP-A-2012-229206, JP-A-2012-6908, and JP-A-2012-72109. , Japanese Patent Application Laid-Open No. 2011-39502 and Japanese Patent Application Laid-Open No. 2011-191745.

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

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

<Preparation of resist composition>
The resist composition of the present invention comprises the resin (A) and the acid generator (B) of the present invention, as well as the resin (X), quencher (C), solvent (E) and other components used as needed. It can be prepared by mixing (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 resin or the like and the solubility of the resin or the like in the solvent (E). The mixing 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 on 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 decompression device. The heating temperature is preferably 50 to 200 ° C., and the heating time is preferably 10 to 180 seconds. The pressure at the time of vacuum drying is preferably about 1~1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed to an exposure machine. The exposure machine may be an immersion exposure machine. Exposure light sources include those that emit ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), and F ₂ excimer laser (wavelength 157 nm), and solid-state laser light sources (YAG or semiconductor laser). Etc.), wavelength-converted laser light from far-ultraviolet region or vacuum ultraviolet region to emit harmonic laser light, electron beam, super-ultraviolet light (EUV) irradiation, etc. 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, the exposure may be performed by drawing directly without using a mask.

The exposed composition layer is heat treated (so-called post-exposure bake) 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 developing solution using a developing device. Examples of the developing method include a dip method, a paddle method, a spray method, and a dynamic dispense method. The developing temperature is preferably 5 to 60 ° C., and the developing time is preferably 5 to 300 seconds. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any 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 developing solution 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 thereof include ether solvents; amide solvents such as N and N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and 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 even 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 developed resist pattern with a rinse 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.

In the resist composition of the present invention, the resin (X) tends to have a high distribution on the surface in the composition layer, and elution of an acid generator or the like into an immersion exposure liquid during immersion exposure can be suppressed. .. In addition, the above-mentioned forward contact angle and backward contact angle caused by the resin (X) exhibit water repellency and enable high-speed scan exposure without leaving water droplets.

<Use>
The resist composition of the present invention includes a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, particularly ArF. It is suitable as a resist composition for excimer laser immersion 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" representing the content or the amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value obtained by gel permeation chromatography under the following conditions.
Equipment: HLC-8120GPC type (manufactured by Tosoh)
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (manufactured by Tosoh)
Eluent: tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh)

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

式（Ｉ−１−ａ）で表される化合物２０部、トルエン１６０部及びピリジン２７．１部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ−１−ｂ）で表される化合物６９部及びトルエン１００部の混合溶液を１時間かけて滴下し、さらに２３℃で１２時間攪拌した。得られた混合物に、イオン交換水１００部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を４回繰り返した。得られた有機層を濃縮した後、得られた濃縮残渣にｎ−ヘプタン１００部を加え、２３℃で３０分間攪拌し、ろ過することにより、式（Ｉ−１−ｃ）で表される化合物３５．９部を得た。 Synthesis Example 1: Synthesis of the compound represented by the formula (I-1)

20 parts of the compound represented by the formula (I-1-a), 160 parts of toluene and 27.1 parts of pyridine were mixed and stirred at 23 ° C. for 30 minutes. A mixed solution of 69 parts of the compound represented by the formula (I-1-b) and 100 parts of toluene was added dropwise to the obtained mixture over 1 hour, and the mixture was further stirred at 23 ° C. for 12 hours. 100 parts of ion-exchanged water was mixed with the obtained mixture, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated 4 times. After concentrating the obtained organic layer, 100 parts of n-heptane is added to the obtained concentrated residue, stirred at 23 ° C. for 30 minutes, and filtered to obtain a compound represented by the formula (I-1-c). 35.9 copies were obtained.

式（Ｉ−１−ｃ）で表される化合物１０部、式（Ｉ−１−ｄ）で表される化合物７．４部及びジメチルホルムアミド７０部を混合し、２３℃で２時間攪拌した。得られた混合物に、イオン交換水５０部及び酢酸エチル２００部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を得た。得られた有機層に、イオン交換水５０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を３回繰り返した。得られた有機層を濃縮することにより、式（Ｉ−１−ｅ）で表される化合物９．７部を得た。

10 parts of the compound represented by the formula (I-1-c), 7.4 parts of the compound represented by the formula (I-1-d) and 70 parts of dimethylformamide were mixed and stirred at 23 ° C. for 2 hours. 50 parts of ion-exchanged water and 200 parts of ethyl acetate were mixed with the obtained mixture, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to obtain an organic layer. 50 parts of ion-exchanged water was mixed with the obtained organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated three times. By concentrating the obtained organic layer, 9.7 parts of the compound represented by the formula (I-1-e) was obtained.

式（Ｉ−１−ｅ）で表される化合物３部、メタノール２４部及び１０％水酸化ナトリウム水溶液３部を混合し、２３℃で２時間攪拌した。得られた反応溶液に、酢酸０．４４部を混合し、２３℃で３０分間攪拌した後、濃縮した。得られた濃縮残渣に、酢酸エチル２０部及びイオン交換水１０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を得た。得られた有機層に、イオン交換水１０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を３回繰り返した。得られた有機層を濃縮し、濃縮マスをカラムクロマトグラフィー（関東化学 シリカゲル６０Ｎ（球状、中性）１００−２１０μｍ 展開溶媒：ｎ−ヘプタン／酢酸エチル＝３／１）を用いて分取することにより、式（Ｉ−１）で表される化合物１部を得た。
ＭＡＳＳ：２９４．１（分子イオンピーク）

3 parts of the compound represented by the formula (I-1-e), 24 parts of methanol and 3 parts of a 10% aqueous sodium hydroxide solution were mixed and stirred at 23 ° C. for 2 hours. 0.44 parts of acetic acid was mixed with the obtained reaction solution, stirred at 23 ° C. for 30 minutes, and then concentrated. 20 parts of ethyl acetate and 10 parts of ion-exchanged water were mixed with the obtained concentrated residue, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to obtain an organic layer. 10 parts of ion-exchanged water was mixed with the obtained organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated three times. The obtained organic layer is concentrated, and the concentrated mass is separated by column chromatography (Kanto Chemical silica gel 60N (spherical, neutral) 100-210 μm developing solvent: n-heptane / ethyl acetate = 3/1). Obtained 1 part of the compound represented by the formula (I-1).
MASS: 294.1 (Molecular ion peak)

式（Ｉ−１−ａ）で表される化合物１０部、テトラヒドロフラン部、ピリジン１１．９０部及びジメチルアミノピリジン１．６７部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ−２−ｂ）で表される化合物２５．８部及びテトラヒドロフラン２５部の混合溶液を２時間かけて滴下し、さらに２３℃で１２時間攪拌した。得られた混合物に、酢酸エチル１００部及びイオン交換水１００部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。得られた有機層に、イオン交換水１００部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を３回繰り返した。得られた有機層を濃縮し、濃縮マスをカラムクロマトグラフィー（関東化学 シリカゲル６０Ｎ（球状、中性）１００−２１０μｍ 展開溶媒：ｎ−ヘプタン／酢酸エチル＝３／１）を用いて分取することにより、式（Ｉ−２−ｃ）で表される化合物１５．８部を得た。 Synthesis Example 2: Synthesis of the compound represented by the formula (I-2)

10 parts of the compound represented by the formula (I-1-a), tetrahydrofuran part, 11.90 part of pyridine and 1.67 part of dimethylaminopyridine were mixed and stirred at 23 ° C. for 30 minutes. A mixed solution of 25.8 parts of the compound represented by the formula (I-2-b) and 25 parts of tetrahydrofuran was added dropwise to the obtained mixture over 2 hours, and the mixture was further stirred at 23 ° C. for 12 hours. 100 parts of ethyl acetate and 100 parts of ion-exchanged water were mixed with the obtained mixture, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. 100 parts of ion-exchanged water was mixed with the obtained organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated three times. The obtained organic layer is concentrated, and the concentrated mass is separated by column chromatography (Kanto Chemical silica gel 60N (spherical, neutral) 100-210 μm developing solvent: n-heptane / ethyl acetate = 3/1). To obtain 15.8 parts of the compound represented by the formula (I-2-c).

式（Ｉ−２−ｃ）で表される化合物１０．７部、式（Ｉ−１−ｄ）で表される化合物７．４部及びジメチルホルムアミド７０部を混合し、２３℃で２時間攪拌した。得られた混合物に、イオン交換水５０部及び酢酸エチル２００部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を得た。得られた有機層に、イオン交換水５０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を３回繰り返した。得られた有機層を濃縮することにより、式（Ｉ−２−ｅ）で表される化合物９．９部を得た。

10.7 parts of the compound represented by the formula (I-2-c), 7.4 parts of the compound represented by the formula (I-1-d) and 70 parts of dimethylformamide are mixed and stirred at 23 ° C. for 2 hours. did. 50 parts of ion-exchanged water and 200 parts of ethyl acetate were mixed with the obtained mixture, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to obtain an organic layer. 50 parts of ion-exchanged water was mixed with the obtained organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated three times. By concentrating the obtained organic layer, 9.9 parts of the compound represented by the formula (I-2-e) was obtained.

式（Ｉ−２−ｅ）で表される化合物３．２部、メタノール２４部及び１０％水酸化ナトリウム水溶液３部を混合し、２３℃で２時間攪拌した。得られた反応溶液に、酢酸０．４部を混合し、２３℃で３０分間攪拌した後、濃縮した。得られた濃縮残渣に、酢酸エチル２０部及びイオン交換水１０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を得た。得られた有機層に、イオン交換水１０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を３回繰り返した。得られた有機層を濃縮し、濃縮マスをカラムクロマトグラフィー（関東化学 シリカゲル６０Ｎ（球状、中性）１００−２１０μｍ 展開溶媒：ｎ−ヘプタン／酢酸エチル＝３／１）を用いて分取することにより、式（Ｉ−２）で表される化合物０．９１部を得た。
ＭＡＳＳ：３２２．１（分子イオンピーク）

3.2 parts of the compound represented by the formula (I-2-e), 24 parts of methanol and 3 parts of a 10% aqueous sodium hydroxide solution were mixed and stirred at 23 ° C. for 2 hours. 0.4 part of acetic acid was mixed with the obtained reaction solution, and the mixture was stirred at 23 ° C. for 30 minutes and then concentrated. 20 parts of ethyl acetate and 10 parts of ion-exchanged water were mixed with the obtained concentrated residue, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to obtain an organic layer. 10 parts of ion-exchanged water was mixed with the obtained organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated three times. The obtained organic layer is concentrated, and the concentrated mass is separated by column chromatography (Kanto Chemical silica gel 60N (spherical, neutral) 100-210 μm developing solvent: n-heptane / ethyl acetate = 3/1). Obtained 0.91 part of the compound represented by the formula (I-2).
MASS: 322.1 (molecular ion peak)

式（Ｉ−３−ａ）で表される化合物２８部、トルエン１６０部及びピリジン２７．１部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ−１−ｂ）で表される化合物６９部及びトルエン１００部の混合溶液を１時間かけて滴下し、さらに２３℃で１２時間攪拌した。得られた混合物に、イオン交換水１００部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を４回繰り返した。得られた有機層を濃縮した後、得られた濃縮残渣にｎ−ヘプタン１００部を加え、２３℃で３０分間攪拌し、ろ過することにより、式（Ｉ−３−ｃ）で表される化合物２２．４部を得た。 Synthesis Example 3: Synthesis of the compound represented by the formula (I-3)

28 parts of the compound represented by the formula (I-3-a), 160 parts of toluene and 27.1 parts of pyridine were mixed and stirred at 23 ° C. for 30 minutes. A mixed solution of 69 parts of the compound represented by the formula (I-1-b) and 100 parts of toluene was added dropwise to the obtained mixture over 1 hour, and the mixture was further stirred at 23 ° C. for 12 hours. 100 parts of ion-exchanged water was mixed with the obtained mixture, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated 4 times. After concentrating the obtained organic layer, 100 parts of n-heptane is added to the obtained concentrated residue, stirred at 23 ° C. for 30 minutes, and filtered to obtain a compound represented by the formula (I-3-c). 22.4 copies were obtained.

式（Ｉ−３−ｃ）で表される化合物１１．５部、式（Ｉ−１−ｄ）で表される化合物７．４部及びジメチルホルムアミド７０部を混合し、２３℃で２時間攪拌した。得られた混合物に、イオン交換水５０部及び酢酸エチル２００部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を得た。得られた有機層に、イオン交換水５０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を３回繰り返した。得られた有機層を濃縮することにより、式（Ｉ−３−ｅ）で表される化合物８．９部を得た。

11.5 parts of the compound represented by the formula (I-3-c), 7.4 parts of the compound represented by the formula (I-1-d) and 70 parts of dimethylformamide are mixed and stirred at 23 ° C. for 2 hours. did. 50 parts of ion-exchanged water and 200 parts of ethyl acetate were mixed with the obtained mixture, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to obtain an organic layer. 50 parts of ion-exchanged water was mixed with the obtained organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated three times. By concentrating the obtained organic layer, 8.9 parts of the compound represented by the formula (I-3-e) was obtained.

式（Ｉ−３−ｅ）で表される化合物３．５部、メタノール２４部及び１０％水酸化ナトリウム水溶液３部を混合し、２３℃で２時間攪拌した。得られた反応溶液に、酢酸０．４４部を混合し、２３℃で３０分間攪拌した後、濃縮した。得られた濃縮残渣に、酢酸エチル２０部及びイオン交換水１０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を得た。得られた有機層に、イオン交換水１０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を３回繰り返した。得られた有機層を濃縮し、濃縮マスをカラムクロマトグラフィー（関東化学 シリカゲル６０Ｎ（球状、中性）１００−２１０μｍ 展開溶媒：ｎ−ヘプタン／酢酸エチル＝３／１）を用いて分取することにより、式（Ｉ−３）で表される化合物１．２８部を得た。
ＭＡＳＳ：３５０．２（分子イオンピーク）

3.5 parts of the compound represented by the formula (I-3-e), 24 parts of methanol and 3 parts of a 10% aqueous sodium hydroxide solution were mixed and stirred at 23 ° C. for 2 hours. 0.44 parts of acetic acid was mixed with the obtained reaction solution, stirred at 23 ° C. for 30 minutes, and then concentrated. 20 parts of ethyl acetate and 10 parts of ion-exchanged water were mixed with the obtained concentrated residue, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to obtain an organic layer. 10 parts of ion-exchanged water was mixed with the obtained organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated three times. The obtained organic layer is concentrated, and the concentrated mass is separated by column chromatography (Kanto Chemical silica gel 60N (spherical, neutral) 100-210 μm developing solvent: n-heptane / ethyl acetate = 3/1). To obtain 1.28 parts of the compound represented by the formula (I-3).
MASS: 350.2 (molecular ion peak)

式（Ｉ−５−ａ）で表される化合物２７．４部、トルエン１６０部及びピリジン２７．１部を混合し、２３℃で３０分間攪拌した。得られた混合物に、式（Ｉ−１−ｂ）で表される化合物６９部及びトルエン１００部の混合溶液を１時間かけて滴下し、さらに２３℃で１２時間攪拌した。得られた混合物に、イオン交換水１００部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を４回繰り返した。得られた有機層を濃縮した後、得られた濃縮残渣にｎ−ヘプタン１００部を加え、２３℃で３０分間攪拌し、ろ過することにより、式（Ｉ−５−ｃ）で表される化合物２６．５部を得た。 Synthesis Example 4: Synthesis of compound represented by formula (I-5)

27.4 parts of the compound represented by the formula (I-5a), 160 parts of toluene and 27.1 parts of pyridine were mixed and stirred at 23 ° C. for 30 minutes. A mixed solution of 69 parts of the compound represented by the formula (I-1-b) and 100 parts of toluene was added dropwise to the obtained mixture over 1 hour, and the mixture was further stirred at 23 ° C. for 12 hours. 100 parts of ion-exchanged water was mixed with the obtained mixture, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated 4 times. After concentrating the obtained organic layer, 100 parts of n-heptane is added to the obtained concentrated residue, stirred at 23 ° C. for 30 minutes, and filtered to obtain a compound represented by the formula (I-5-c). 26.5 copies were obtained.

式（Ｉ−５−ｃ）で表される化合物１１．４部、式（Ｉ−１−ｄ）で表される化合物７．４部及びジメチルホルムアミド７０部を混合し、２３℃で２時間攪拌した。得られた混合物に、イオン交換水５０部及び酢酸エチル２００部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を得た。得られた有機層に、イオン交換水５０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を３回繰り返した。得られた有機層を濃縮することにより、式（Ｉ−５−ｅ）で表される化合物１０．２部を得た。

11.4 parts of the compound represented by the formula (I-5-c), 7.4 parts of the compound represented by the formula (I-1-d) and 70 parts of dimethylformamide are mixed and stirred at 23 ° C. for 2 hours. did. 50 parts of ion-exchanged water and 200 parts of ethyl acetate were mixed with the obtained mixture, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to obtain an organic layer. 50 parts of ion-exchanged water was mixed with the obtained organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated three times. By concentrating the obtained organic layer, 10.2 parts of the compound represented by the formula (I-5-e) was obtained.

式（Ｉ−５−ｅ）で表される化合物３．４部、メタノール２４部及び１０％水酸化ナトリウム水溶液３部を混合し、２３℃で２時間攪拌した。得られた反応溶液に、酢酸０．４４部を混合し、２３℃で３０分間攪拌した後、濃縮した。得られた濃縮残渣に、酢酸エチル２０部及びイオン交換水１０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を得た。得られた有機層に、イオン交換水１０部を混合し、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を３回繰り返した。得られた有機層を濃縮し、濃縮マスをカラムクロマトグラフィー（関東化学 シリカゲル６０Ｎ（球状、中性）１００−２１０μｍ 展開溶媒：ｎ−ヘプタン／酢酸エチル＝３／１）を用いて分取することにより、式（Ｉ−５）で表される化合物１．２９部を得た。
ＭＡＳＳ：３４８．１（分子イオンピーク）

3.4 parts of the compound represented by the formula (I-5e), 24 parts of methanol and 3 parts of a 10% aqueous sodium hydroxide solution were mixed and stirred at 23 ° C. for 2 hours. 0.44 parts of acetic acid was mixed with the obtained reaction solution, stirred at 23 ° C. for 30 minutes, and then concentrated. 20 parts of ethyl acetate and 10 parts of ion-exchanged water were mixed with the obtained concentrated residue, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to obtain an organic layer. 10 parts of ion-exchanged water was mixed with the obtained organic layer, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such a washing operation was repeated three times. The obtained organic layer is concentrated, and the concentrated mass is separated by column chromatography (Kanto Chemical silica gel 60N (spherical, neutral) 100-210 μm developing solvent: n-heptane / ethyl acetate = 3/1). To obtain 1.29 parts of the compound represented by the formula (I-5).
MASS: 348.1 (Molecular ion peak)

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

Example 1 [Synthesis of resin A1]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-1), a monomer (a3-4-2) and a compound (I-1) are used, and the molars thereof are used. The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-1): monomer (a3-4-2): compound (I-1)] is 35:15: The mixture was mixed so as to have a ratio of 2.5: 47.5: 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 75 ° 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 resulting resin was added to a methanol / water mixed solvent, after repulping, performed twice a purification operation that filtered to give the resin A1 having a weight-average molecular weight 9.0 × 10 ³ in 63% yield. This resin A1 has the following structural units.

Example 2 [Synthesis of resin A2]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-1), a monomer (a3-4-2) and a compound (I-2) are used, and the molars thereof are used. The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-1): monomer (a3-4-2): compound (I-2)] is 35:15: The same operation as in Example 1 was carried out except that the mixture was mixed so as to have a ratio of 2.5: 47.5: 5, and ^{a resin A2 having a weight average molecular weight of 8.7 × 10 3} was obtained in a yield of 60%. This resin A2 has the following structural units.

Example 3 [Synthesis of resin A3]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a2-1-1), a monomer (a3-4-2) and a compound (I-1) are used, and the molars thereof are used. The ratio [monomer (a1-1-3): monomer (a1-2-11): monomer (a2-1-1): monomer (a3-4-2): compound (I-1)] is 35:15: The same procedure as in Example 1 was carried out except that the mixture was mixed so as to have a ratio of 2.5: 47.5: 5, and ^{a resin A3 having a weight average molecular weight of 8.6 × 10 3} was obtained in a yield of 64%. This resin A3 has the following structural units.

Example 4 [Synthesis of resin A4]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a2-1-1), a monomer (a3-4-2) and a compound (I-2) are used, and the molars thereof are used. The ratio [monomer (a1-1-3): monomer (a1-2-11): monomer (a2-1-1): monomer (a3-4-2): compound (I-2)] is 35:15: The same procedure as in Example 1 was carried out except that the mixture was mixed so as to have a ratio of 2.5: 47.5: 5, and ^{a resin A4 having a weight average molecular weight of 8.9 × 10 3} was obtained in a yield of 60%. This resin A4 has the following structural units.

Example 5 [Synthesis of resin A5]
As the monomer, a monomer (a1-2-1), a monomer (a1-2-7), a monomer (a2-1-2), a monomer (a3-4-2) and a compound (I-2) are used, and the molars thereof are used. The ratio [monomer (a1-2-1): monomer (a1-2-7): monomer (a2-1-2): monomer (a3-4-2): compound (I-2)] is 31: 9: The same procedure as in Example 1 was carried out except that the mixture was mixed so as to have a ratio of 22:38:3.5, and ^{a resin A5 having a weight average molecular weight of 7.6 × 10 3} was obtained in a yield of 78%. This resin A5 has the following structural units.

Example 6 [Synthesis of Resin A6]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-1), a monomer (a3-4-2) and a compound (I-3) are used, and the molars thereof are used. The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-1): monomer (a3-4-2): compound (I-3)] is 35:15: The same procedure as in Example 1 was carried out except that the mixture was mixed so as to have a ratio of 2.5: 47.5: 5, and ^{a resin A6 having a weight average molecular weight of 8.5 × 10 3} was obtained in a yield of 63%. This resin A6 has the following structural units.

Example 7 [Synthesis of Resin A7]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-1), a monomer (a3-4-2) and a compound (I-5) are used, and the molars thereof are used. The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-1): monomer (a3-4-2): compound (I-5)] is 35:15: The same procedure as in Example 1 was carried out except that the mixture was mixed so as to have a ratio of 2.5: 47.5: 5, and ^{a resin A7 having a weight average molecular weight of 8.1 × 10 3} was obtained in a yield of 60%. This resin A7 has the following structural units.

Example 8 [Synthesis of resin A8]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-3), a monomer (a3-4-2) and a compound (I-1) are used, and the molars thereof are used. The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-4-2): compound (I-1)] is 35:15: The same procedure as in Example 1 was carried out except that the mixture was mixed so as to have a ratio of 2.5: 47.5: 5, and ^{a resin A8 having a weight average molecular weight of 8.6 × 10 3} was obtained in a yield of 68%. This resin A8 has the following structural units.

Example 9 [Synthesis of Resin A9]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-3), a monomer (a3-4-2) and a compound (I-3) are used, and the molars thereof are used. The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-4-2): compound (I-3)] is 35:15: The same procedure as in Example 1 was carried out except that the mixture was mixed so as to have a ratio of 2.5: 47.5: 5, and ^{a resin A9 having a weight average molecular weight of 8.1 × 10 3} was obtained in a yield of 60%. This resin A9 has the following structural units.

Example 10 [Synthesis of resin A10]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-3), a monomer (a3-4-2) and a compound (I-5) are used, and the molars thereof are used. The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-4-2): compound (I-5)] is 35:15: The same procedure as in Example 1 was carried out except that the mixture was mixed so as to have a ratio of 2.5: 47.5: 5, and ^{a resin A10 having a weight average molecular weight of 7.9 × 10 3} was obtained in a yield of 57%. This resin A10 has the following structural units.

Synthesis Example 5 [Synthesis of resin AX1]
As the monomer, a monomer (a1-2-1), a monomer (a1-2-7), a monomer (a2-1-2), a monomer (a3-x1) and a compound (I-2) are used, and their molar ratios [ Monomer (a1-2-1): Monomer (a1-2-7): Monomer (a2-1-2): Monomer (a3-x1): Compound (I-2)] is 31: 9: 22: 38: The mixture was mixed so as to have a concentration of 3.5, and propylene glycol monomethyl ether acetate 1.5% by mass of the total amount of 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 75 ° 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 resulting resin was added to a methanol / water mixed solvent, after repulping, performed twice a purification operation of filtration, to obtain a resin AX1 of the weight average molecular weight 7.3 × 10 ³ in 76% yield. This resin AX1 has the following structural units.

Synthesis Example 6 [Synthesis of resin X1]
A monomer (a4-1-7) was used as a monomer, and methyl isobutyl ketone 1.5% by mass of the total amount of the monomer was added to prepare a solution. Azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the solution in an amount of 0.7 mol% and 2.1 mol%, respectively, based on the total amount of the monomers, and these were added at 75 ° C. It was heated for about 5 hours. The reaction mixture obtained, the resin was precipitated by pouring into a large amount of methanol / water mixed solvent, the resin was filtered, to obtain a resin X1 of weight average molecular weight 1.8 × 10 ⁴ in 77% yield. This resin X1 has the following structural units.

Synthesis Example 7 [Synthesis of resin X2]
As the monomer, a monomer (a5-1-1) and a monomer (a4-0-12) are used, and the molar ratio [monomer (a5-1-1): monomer (a4-0-12)] is 50:50. Methyl isobutyl ketone was added in an amount 1.2% by mass of the total amount of the monomers 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 reaction mixture obtained, the resin was precipitated by pouring into a large amount of methanol / water mixed solvent, the resin was filtered, the weight-average molecular weight 1.0 × 10 ⁴ of the resin X2 (copolymer) to yield 91% I got it in. This resin X2 has the following structural units.

<Preparation of resist composition>
As shown in Table 1, 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.

<Resin>
A1 to A10, AX1, X1, X2: Resin A1 to Resin A10, Resin AX1, Resin X1, Resin X2
<Acid generator>
B1-21: A salt represented by the formula (B1-21) (synthesized according to an example of JP2012-224611).
B1-22: A salt represented by the formula (B1-22) (synthesized according to an example of JP2012-224611).

<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 produce 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 listed in the "PB" column of Table 1 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: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Anal XY polarized light). / Using a mask for forming a hole diameter of 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 1 for 60 seconds. Next, the composition layer on the silicon wafer was developed by the dynamic dispensing method at 23 ° C. for 20 seconds using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution to form a negative resist pattern. Manufactured.

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

<Mask error factor (MEF) evaluation>
In terms of effective sensitivity, a resist pattern was formed using masks having mask hole diameters (hole diameters of translucent portions of the mask) of 57 nm, 56 nm, 55 nm, 54 nm, and 53 nm (hole pitches are all 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 5.0 or less are evaluated as having a good MEF, and are marked with ○.
Those having a MEF value of more than 5.0 were evaluated as having poor MEF and were evaluated as x.
The results are shown in Table 2. The numbers in parentheses indicate the MEF value.

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

Claims (8)

A resin containing a structural unit represented by the formula (I) and a structural unit represented by the formula (a3-4).

[In formula (I), A ¹ represents a single bond or a divalent hydrocarbon group having 1 to 18 carbon atoms.
A ² and A ³ each independently represent a divalent hydrocarbon group having 1 to 18 carbon atoms.
R ¹ and R ² each independently represent a saturated hydrocarbon group having 1 to 6 carbon atoms.
R ³ and R ⁴ each independently represent a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. ]

Wherein ^{(a3-4), R a24} represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
L ^a7 is a single bond, ^* -L ^a8- O-, ^* -L ^a8- CO-O-, ^* -L ^a8- CO-O-L ^a9- CO-O- or ^* -L ^a8- O-CO. Represents −L ^a9 −O−.
* Represents a bond with -O-.
^{La 8} and ^{La 9} each independently represent an alkanediyl group having 1 to 6 carbon atoms.
^Ra25 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
w1 represents any integer from 0 to 8. When w1 is 2 or more, the plurality of Ra ^25s may be the same or different from each other. ] The resin according to claim 1, wherein A ² and A ³ are each independently a methylene group or an ethylene group. The resin according to claim 1 or 2, wherein A ¹ is an alkanediyl group having 1 to 8 carbon atoms. The resin according to any one of claims 1 to 3, further comprising a structural unit having an acid unstable group. A resist composition containing the resin and acid generator according to any one of claims 1 to 4. The resist composition according to claim 5, further comprising a resin containing a structural unit having a fluorine atom. The resist composition according to claim 5 or 6, further comprising a salt that generates an acid having a weaker acidity than the acid generated from the acid generator. (1) A step of applying the resist composition according to any one of claims 5 to 7 onto a substrate.
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
(4) A step of heating the composition layer after exposure, and (5) A step of developing the composition layer after heating,
A method for producing a resist pattern including.