JP6748495B2 - Resist composition - Google Patents

Description

The present invention relates to a resist composition.

特許文献２には、下記構造単位の組合せからなる樹脂（下図左から、モル比３０：３０：４０）を含むレジスト組成物が記載されている。

Patent Document 1 describes a resist composition containing a resin (from the left in the figure below, the molar ratio is 40:20:40) made of a combination of the following structural units.

Patent Document 2 describes a resist composition containing a resin (from the left in the figure below, the molar ratio is 30:30:40) composed of a combination of the following structural units.

JP, 2002-155118, A JP, 2011-227463, A

The resist pattern formed from the above resist composition may not always be satisfactory in terms of residue and line edge roughness (LER).

［式（ａ４−０）中、
Ｒ^５は、水素原子又はメチル基を表す。
Ｌ^４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３〜１２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。］
［２］Ｌ^３が、炭素数１〜２のペルフルオロアルカンジイル基である［１］記載のレジスト組成物。
［３］Ｒ^６が、フッ素原子である［１］又は［２］記載のレジスト組成物。
［４］式（ａ４−０）で表される構造単位の含有率が、樹脂（Ａ１）の全構造単位の合計に対して、０．５モル％以上４．５モル％以下である［１］〜［３］のいずれか記載のレジスト組成物。
［５］酸不安定基を有する構造単位が、式（ａ１−１）で表される構造単位又は式（ａ１−２）で表される構造単位を有する［１］〜［４］のいずれか記載のレジスト組成物。

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^ａ１及びＬ^ａ２は、互いに独立に、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ１−ＣＯ−Ｏ−を表し、ｋ１は１〜７の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^ａ４及びＲ^ａ５は、互いに独立に、水素原子又はメチル基を表す。
Ｒ^ａ６及びＲ^ａ７は、互いに独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合せた基を表す。
ｍ１は、０〜１４の整数を表す。
ｎ１は、０〜１０の整数を表す。
ｎ１’は、０〜３の整数を表す。］
［６］酸発生剤が、式（Ｂ１）で表される塩である［１］〜［５］のいずれか記載のレジスト組成物。

［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１価の脂環式炭化水素基を表し、該メチル基及び該１価の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。］
［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［１］〜［６］のいずれか記載のレジスト組成物。
［８］レジスト組成物が、フッ素原子を有し、かつ、酸不安定基を有する構造単位を含まない樹脂（Ａ２）をさらに含有する［１］〜［７］のいずれか記載のレジスト組成物。
［９］（１）［１］〜［８］のいずれか記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層に露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A resist composition containing a resin (A1) containing a structural unit represented by the formula (a4-0) and a structural unit having an acid labile group, and an acid generator,
The resist composition, wherein the content of the structural unit represented by the formula (a4-0) is 0.5 mol% or more and 9.5 mol% or less based on the total of all structural units of the resin (A1).

[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]
[2] The resist composition according to [1], wherein L ³ is a perfluoroalkanediyl group having 1 to 2 carbon atoms.
[3] The resist composition according to [1] or [2], wherein R ⁶ is a fluorine atom.
[4] The content of the structural unit represented by the formula (a4-0) is 0.5 mol% or more and 4.5 mol% or less based on the total of all structural units of the resin (A1) [1. ] The resist composition in any one of [3].
[5] The structural unit having an acid labile group is any one of [1] to [4] having a structural unit represented by the formula (a1-1) or a structural unit represented by the formula (a1-2). The resist composition described.

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or *—O—(CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond with —CO—. Representing a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these.
m1 represents the integer of 0-14.
n1 represents the integer of 0-10.
n1' represents the integer of 0-3. ]
[6] The resist composition according to any one of [1] to [5], wherein the acid generator is a salt represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the methyl group and the monovalent it is, -O - - -CH ₂ contained in the alicyclic hydrocarbon group, - SO ₂ - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]
[7] The resist composition according to any one of [1] to [6], further including a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.
[8] The resist composition according to any one of [1] to [7], wherein the resist composition further contains a resin (A2) having a fluorine atom and not containing a structural unit having an acid labile group. ..
[9] (1) A step of applying the resist composition according to any one of [1] to [8] onto a substrate,
(2) a step of drying the composition after coating to form a composition layer,
(3) a step of exposing the composition layer,
A method for producing a resist pattern, which comprises (4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

According to the resist composition of the present invention, a residue is not generated and a resist pattern having a good line edge roughness (LER) can be manufactured.

In the present specification, “(meth)acrylate” means “at least one of acrylate and methacrylate”. The expressions such as “(meth)acrylic acid” and “(meth)acryloyl” have the same meaning.
Further, unless otherwise specified, a group which can be linear or branched, such as an “aliphatic hydrocarbon group”, includes both of them. The "aromatic hydrocarbon group" also includes a group in which a hydrocarbon group is bonded to an aromatic ring. When stereoisomers are present, all stereoisomers are included.
In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent (E) described below from the total amount of the resist composition.

[Resist composition]
The resist composition of the present invention contains a resin (A1) and an acid generator (hereinafter sometimes referred to as “acid generator (B)”).
The resist composition may further contain a resin (A2) containing a structural unit having a fluorine atom and not containing a structural unit having an acid labile group.
In addition, the resist composition contains a quencher such as a salt (hereinafter sometimes referred to as “quencher (C)”) that generates an acid having a weaker acidity than an acid generated from the acid generator and/or a solvent (hereinafter, “quencher (C)”). It may contain a solvent (E)” in some cases.

<Resin (A1)>
The resin (A1) includes a structural unit represented by the formula (a4-0) (hereinafter sometimes referred to as “structural unit (a4-0)”) and a structural unit having an acid labile group (hereinafter referred to as “structural unit”). (A1)").
The “acid-labile group” of the structural unit is a group having a leaving group, which has a hydrophilic group (for example, a hydroxy group or a carboxyl group) when the leaving group is released by contact with an acid. It means a group converted into a structural unit.
The resin (A1) may further have a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”) and other structural units (hereinafter sometimes referred to as “structural unit (t)”). ) And/or structural units known in the art.

［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３〜１２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 (a4-0)>
The resin (A1) contains the structural unit (a4-0), and the content rate thereof is 0.5 mol% or more and 9.5 mol% or less based on the total of all structural units of the resin (A1). , Preferably 0.5 mol% or more and 7.5 mol% or less, more preferably 0.5 mol% or more and 4.5 mol% or less, and further preferably 1 mol% or more and 4 mol% or less, More preferably, it is 2.5 mol% or more and 4 mol% or less.

[In the formula (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 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

As the aliphatic saturated hydrocarbon group for L ⁵ , a linear alkanediyl group such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, or a linear alkanediyl group. Having a side chain of an alkyl group (especially, methyl group, ethyl group, etc.), ethane-1,1-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2 Examples include branched alkanediyl groups such as -methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
L ⁴ is 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.

Examples of the perfluoroalkanediyl group for L ³ include a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group and a perfluoropropane-2,2. -Diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane-2,2 -Diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7 -Diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2 -Diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like.
Examples of the perfluorocycloalkanediyl group for L ³ include perfluorocyclopropane-1,3-diyl group, perfluorocyclobutane-2,2-diyl group, perfluorocyclopentane-1,5-diyl group, perfluorocyclohexane-1,6- Examples thereof include a diyl group and a perfluorocycloadamantyl-1,2-diyl group.

L ⁵ is preferably a single bond, a methylene group or an ethylene group, and more preferably a single bond or a methylene group.
L ³ is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms or a perfluorocycloalkanediyl group having 3 to 10 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms, and further preferably It is a perfluoroalkanediyl group having 1 to 2 carbon atoms, and particularly preferably a difluoromethylene group.
R ⁶ is preferably a fluorine atom.

Examples of the structural unit (a4-0) include the structural units shown below.

The monomer (a4-0) for deriving the structural unit (a4-0) is easily available from the market.

［式（１）中、Ｒ^ａ１〜Ｒ^ａ３は、互いに独立に、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合せた基を表すか、又は、Ｒ^ａ１及びＲ^ａ２は互いに結合して炭素数２〜２０の２価の炭化水素基を形成し、Ｒ^ａ３は、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合せた基を表す。
ｎａは、０又は１を表す。
＊は、結合手を表す。］ <Structural unit (a1)>
The resin (A1) contains the structural unit (a1) in addition to the structural unit (a4-0).
The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”).
The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth)acrylic monomer having an acid labile group.
In the resin (A1), the acid labile group contained in the structural unit (a1) is preferably a group represented by the following formula (1) and/or a group represented by the following formula (2).

[In the formula (1), R ^{a1 to} R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group in which these are combined, or , R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and R ^a3 is an alkyl group having 1 to 8 carbon atoms and an alicyclic carbon group having 3 to 20 carbon atoms. It represents a hydrogen group or a group combining these.
na represents 0 or 1.
* Represents a bond. ]

［式（２）中、Ｒ^ａ１’及びＲ^ａ２’は、互いに独立に、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、又は、Ｒ^ａ１’は、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^ａ２’及びＲ^ａ３’は互いに結合してそれらが結合する炭素原子及びＸとともに炭素数３〜２０の２価の複素環基を形成し、該炭化水素基及び該２価の複素環基に含まれる−ＣＨ_２−は、−Ｏ−又は−Ｓ−で置き換わってもよい。
Ｘは、酸素原子又は硫黄原子を表す。
＊は、結合手を表す。］

[In formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. Or R ^{a1 ′} represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^{a2 ′} and R ^{a3 ′} are bonded to each other and the carbon atom to which they are bonded and X are 3 to 3 carbon atoms. 20 divalent heterocyclic groups are formed, and —CH ₂ — contained in the hydrocarbon group and the divalent heterocyclic group may be replaced with —O— or —S—.
X represents an oxygen atom or a sulfur atom.
* Represents a bond. ]

アルキル基と脂環式炭化水素基とを組合せた基としては、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等が挙げられる。 ^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 and an n-octyl group.
The alicyclic hydrocarbon group 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, the following groups (* represents a bond), and the like.
The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 3 to 16 carbon atoms.

Examples of the group in which an alkyl group and an alicyclic hydrocarbon group are combined include a methylcyclohexyl group, a dimethylcyclohexyl group and a methylnorbornyl group.

In the case where R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group, -C(R ^a1 )(R ^a2 )(R ^a3 ) includes the groups below, and * represents -O-. Represents a bond with. The carbon number of the divalent hydrocarbon group is preferably 3-12.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (a group in which R ^{a1 to} R ^a3 in the formula (1) are alkyl groups, preferably a tert-butoxycarbonyl group), 2- An alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are bonded to each other, and together with the carbon atom to which they are bonded to form an adamantyl group, R ^a3 is an alkyl group; 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 of R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group and the alicyclic hydrocarbon group are the same as those mentioned above.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, xylyl group, cumyl group, mesityl group, biphenyl group and phenanthryl group. Group, an aryl group such as a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, and the like.
^{Examples of the} divalent heterocyclic group formed by R ^{a2 ′} and R ^{a3 ′} bonded to each other and the carbon atom to which they are bonded and X include the following groups. * Represents a bond.

At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

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

Among the (meth)acrylic monomers having an acid labile group, a (meth)acrylic monomer having an alicyclic hydrocarbon group having 5 to 20 carbon atoms is preferable. From the resist composition containing the resin (A1) having a structural unit derived from the monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group, a resist pattern with further improved resolution can be formed.

Preferred examples of the structural unit derived from the (meth)acrylic monomer having a group represented by the formula (1) include a structural unit represented by the formula (a1-0) and a structural unit represented by the formula (a1-1). And a structural unit represented by the formula (a1-2). These may be used alone or in combination of two or more. In the present specification, the structural unit represented by the formula (a1-0), the structural unit represented by the formula (a1-1), and the structural unit represented by the formula (a1-2) are respectively represented by the structural unit (a1 -0), a structural unit (a1-1) and a structural unit (a1-2) may be referred to, and a monomer that induces the structural unit (a1-0), a monomer that induces the structural unit (a1-1), and a structural unit The monomer that induces (a1-2) may be referred to as a monomer (a1-0), a monomer (a1-1), and a monomer (a1-2), respectively.

［式（ａ１−０）中、
Ｌ^ａ０１は、酸素原子又は＊−Ｏ−（ＣＨ_２）_ｋ０１−ＣＯ−Ｏ−を表し、ｋ０１は１〜７の整数を表し、＊はカルボニル基との結合手を表す。
Ｒ^ａ０１は、互いに独立に、水素原子又はメチル基を表す。
Ｒ^ａ０２、Ｒ^ａ０３及びＲ^ａ０４は、互いに独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合せた基を表す。］

[In the formula (a1-0),
L ^a01 represents an oxygen atom or *—O—(CH ₂ ) _k01 —CO—O—, k01 represents an integer of 1 to 7, and * represents a bond with a carbonyl group.
R ^a01 independently represents a hydrogen atom or a methyl group.
R ^a02 , R ^a03, and R ^a04 each independently ^represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these. ]

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^ａ１及びＬ^ａ２は、互いに独立に、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ１−ＣＯ−Ｏ−を表し、ｋ１は１〜７の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^ａ４及びＲ^ａ５は、互いに独立に、水素原子又はメチル基を表す。
Ｒ^ａ６及びＲ^ａ７は、互いに独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合せることにより形成される基を表す。
ｍ１は、０〜１４の整数を表す。
ｎ１は、０〜１０の整数を表す。
ｎ１’は、０〜３の整数を表す。］

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or *—O—(CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond with —CO—. Representing a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents the integer of 0-14.
n1 represents the integer of 0-10.
n1' represents the integer of 0-3. ]

L ^a02 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, and more preferably 1.
Examples of the alkyl group of R ^a02 , R ^a03, and R ^a04 , the alicyclic hydrocarbon group, and a group in which these are combined include the same groups as those described for R ^{a1 to} R ^a3 of the formula (1).
The alkyl group of R ^a02 , R ^a03 and R ^a04 preferably has 6 or less carbon atoms.
The carbon number of the alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^a04 is preferably 3 or more and 8 or less, and more preferably 3 or more and 6 or less.
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 which these alkyl groups and the alicyclic hydrocarbon group are combined. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group or an ethyl group.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.

L ^a1 and L ^a2 are preferably —O— or *—O—(CH ₂ ) _k1′ —CO—O—, more preferably —O—. k1′ is an integer of 1 to 4, preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
^Examples of the alkyl group of R ^a6 and R ^a7 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, Examples thereof include n-heptyl group, 2-ethylhexyl group and n-octyl group.
The alicyclic hydrocarbon group for R ^a6 and R ^a7 may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group. Examples thereof include a cycloalkyl group such as a group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a 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, a norbornyl group, Examples thereof include 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 carbon number of the alkyl group of R ^a6 and R ^a7 is preferably 6 or less.
The alicyclic hydrocarbon group of R ^a6 and R ^a7 is preferably an alicyclic hydrocarbon group having 3 to 8 carbon atoms, and more preferably an alicyclic hydrocarbon group having 3 to 6 carbon atoms.
m1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1′ is preferably 0 or 1.

As the structural unit (a1-0), structural units represented by formulas (a1-0-1) to (a1-1-12) and a methyl group corresponding to R ^a01 in these structural units are hydrogen atoms. The substituted structural unit is mentioned, Preferably it is a structural unit represented by either formula (a1-0-1)-formula (a1-1-10).

Examples of the monomer (a1-1) include the monomers described in JP2010-204646A. Among them, the monomers represented by the following formulas (a1-1-1) to (a1-1-8) are preferable, and the monomers represented by the formulas (a1-1-1) to (a1-1-4) are preferred. Is more preferable.

Examples of the monomer (a1-2) include monomers represented by the following formula (a1-2-1) to formula (a1-2-12), and formula (a1-2-3) and formula (a1-2). -4), monomers represented by formula (a1-2-9) and formula (a1-2-10) are preferable, and monomers represented by formula (a1-2-3) and formula (a1-2-9) are represented. Monomers are more preferred.

When the resin (A1) contains the structural unit (a1-0) and/or the structural unit (a1-1) and/or the structural unit (a1-2), the total content of these is the total structure of the resin (A1). It is usually 10 to 95 mol%, preferably 15 to 90 mol%, and more preferably 20 to 85 mol% based on the total of the units.

［式（ａ１−３）中、
Ｒ^ａ９は、ヒドロキシ基を有していてもよい炭素数１〜３の脂肪族炭化水素基、カルボキシ基、シアノ基、水素原子又は−ＣＯＯＲ^ａ１３を表す。
Ｒ^ａ１３は、炭素数１〜８の脂肪族炭化水素基、炭素数３〜２０の脂環式炭化水素基、又はこれらを組合せることにより形成される基を表し、該脂肪族炭化水素基及び該脂環式炭化水素基に含まれる水素原子は、ヒドロキシ基で置換されていてもよく、該脂肪族炭化水素基及び該脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
Ｒ^ａ１０、Ｒ^ａ１１及びＲ^ａ１２は、互いに独立に、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合せることにより形成される基を表すか、又は、Ｒ^ａ１２は、互いに独立に、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合せることにより形成される基を表し、Ｒ^ａ１０及びＲ^ａ１１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２〜２０の２価の炭化水素基を形成する。］ Further, the structural unit (a1) having a group represented by the formula (1) also includes a structural unit represented by the formula (a1-3). The structural unit represented by the formula (a1-3) may be referred to as a structural unit (a1-3). Further, the monomer that induces the structural unit (a1-3) may be referred to as a monomer (a1-3).

[In the formula (a1-3),
R ^a9 represents an aliphatic hydrocarbon group which may have a hydroxy group and has 1 to 3 carbon atoms, a carboxy group, a cyano group, a hydrogen atom or —COOR ^a13 .
R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining these, and the aliphatic hydrocarbon group and The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxy group, and —CH ₂ — contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is —O—. Alternatively, it may be replaced with -CO-.
R ^a10 , R ^a11, and R ^a12 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining these. ^{or, R a12} are each independently an alkyl group having 1 to 8 carbon atoms, a group formed by combining the alicyclic hydrocarbon group or those having 3 to 20 carbon ^{atoms, R a10} and ^{R a11} Combine with each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the carbon atom to which they are bonded. ]

Here, examples of —COOR ^a13 include groups in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group.

Examples of the aliphatic hydrocarbon group which may have a hydroxy group for R ^a9 include a methyl group, an ethyl group, an n-propyl group, a hydroxymethyl group and a 2-hydroxyethyl group.
^Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms of R ^a13 include a methyl group, an ethyl group and an n-propyl group.
^Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms of R ^a13 include a cyclopentyl group, a cyclopropyl group, an adamantyl group, an adamantyl methyl group, a 1-adamantyl-1-methylethyl group, and 2-oxo-oxolane-3-. Examples thereof include an yl group and a 2-oxo-oxolan-4-yl group.
^Examples of the alkyl group of R ^{a10 to} R ^a12 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, Examples thereof include n-heptyl group, 2-ethylhexyl group and n-octyl group.
The alicyclic hydrocarbon group of R ^{a10 to} R ^a12 may be monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group may be a cyclopropyl group, Examples thereof include cycloalkyl groups such as cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl 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, a norbornyl group, Examples thereof include a methylnorbornyl group and an isobornyl group.
In the case where R ^a10 and R ^a11 are bonded to each other to form a divalent hydrocarbon group together with the carbon atom to which they are bonded, -C(R ^a10 )(R ^a11 )(R ^a12 ) is as follows. Groups are preferred.

Specific examples of the monomer (a1-3) include 5-tert-butyl 5-norbornene-2-carboxylic acid, 1-cyclohexyl-1-methylethyl 5-norbornene-2-carboxylic acid, and 5-norbornene-2-carboxylic acid. Acid 1-methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl, 5-norbornene-2-carboxylic acid 1-(4 -Methylcyclohexyl)-1-methylethyl, 5-norbornene-2-carboxylic acid 1-(4-hydroxycyclohexyl)-1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1-(4-oxo Cyclohexyl)ethyl and 1-(1-adamantyl)-1-methylethyl 5-norbornene-2-carboxylic acid.

Since the resin (A1) containing the structural unit (a1-3) contains a sterically bulky structural unit, a resist composition containing such a resin (A1) can be used to form a resist with higher resolution. You can get the pattern. Further, since a rigid norbornane ring is introduced into the main chain, the obtained resist pattern tends to have excellent dry etching resistance.

When the resin (A1) contains the structural unit (a1-3), its content is preferably 10 to 95 mol% with respect to the total of all structural units of the resin (A1), and 15 to 90 mol%. %, more preferably 20 to 85 mol %.

［式（ａ１−４）中、
Ｒ^ａ３２は、水素原子、ハロゲン原子、又は、ハロゲン原子を有してもよい炭素数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のアシル基、炭素数２〜４のアシルオキシ基、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、互いに独立に、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、又は、Ｒ^ａ３４は、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^ａ３５及びＲ^ａ３６は互いに結合して炭素数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−ＣＨ_２−は、−Ｏ−又は−Ｓ−で置き換わってもよい。］ As the structural unit (a1) having a group represented by the group (2), a structural unit represented by the formula (a1-4) (hereinafter, may be referred to as “structural unit (a1-4)”). Can be mentioned.

[In the formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or Represents a methacryloyloxy group.
la represents an integer of 0 to 4. When la is 2 or more, a plurality of R ^a33 may be the same or different from each other.
R ^a34 and ^{R a35} are independently of each other, represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon ^atoms, or ^{R a36} represents a hydrocarbon group having 1 to 20 carbon atoms, ^{or, R a34} is hydrogen represents an atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a35 and R ^a36 are bonded together to form a divalent hydrocarbon group having 2 to 20 carbon atoms with each other, the carbonization of the hydrocarbon group and the divalent -CH ₂ contained in the hydrogen radical - may be replaced by -O- or -S-. ]

^Examples of the alkyl group of R ^a32 and R ^a33 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an n-pentyl group and an n-hexyl group, and preferably a carbon number of 1 to 4 And an alkyl group are more preferable, a methyl group or an ethyl group is more preferable, and a methyl group is more preferable.
Examples of the halogen atom of R ^a32 and R ^a33 include a fluorine atom, a chlorine atom and a bromine atom.
Examples of the alkyl group 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, 1,1,2,2-tetrafluoro Ethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluoro Butyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl group, n-perfluorohexyl group, 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. Especially, a C1-C4 alkoxy group is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further preferable.
Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group and the like.
Examples of the hydrocarbon group R ^a34 and ^{R a35,} include the same groups as ^{R a1 'and R a2'} of formula (2).
R ^a36 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, and a group formed by combining these. Can be mentioned.

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

Examples of the monomer that leads to the structural unit (a1-4) include the monomers described in JP2010-204646A. Especially, the monomer represented by Formula (a1-4-1)-Formula (a1-4-8) is preferable, and the monomer represented by Formula (a1-4-1)-Formula (a1-4-5) is More preferable.

When the resin (A1) has the structural unit (a1-4), its content is preferably 10 to 95 mol% with respect to the total of all structural units of the resin (A1), and preferably 15 to 90. It is more preferably mol%, and further preferably 20 to 85 mol%.

［式（ａ１−５）中、
Ｒ^ａ８は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｚ^ａ１は、単結合又は＊−（ＣＨ_２）_ｈ３−ＣＯ−Ｌ^５４−を表し、ｈ３は１〜４の整数を表し、＊は、Ｌ^５１との結合手を表す。
Ｌ^５１、Ｌ^５２、Ｌ^５３及びＬ^５４は、互いに独立に、−Ｏ−又は−Ｓ−を表す。
ｓ１は、１〜３の整数を表す。
ｓ１’は、０〜３の整数を表す。］ The structural unit having an acid labile group also includes a structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as “structural unit (a1-5)”).

[In formula (a1-5),
^Ra8 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-.
s1 represents an integer of 1 to 3.
s1' represents the integer of 0-3. ]

In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably —O—.
It is preferable that one of L ⁵² and L ⁵³ is -O-, and the other is -S-.
s1 is preferably 1.
s1′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or *—CH ₂ —CO—O—.

Examples of the monomer that leads to the structural unit (a1-5) include the monomers described in JP 2010-61117A. Among them, the monomers represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and the monomers represented by formula (a1-5-1) and formula (a1-5-2) are More preferable.

When the resin (A1) has the structural unit (a1-5), its content is preferably 1 to 50 mol% with respect to the total of all structural units of the resin (A1), and 3 to 45. It is more preferably mol%, and further preferably 5 to 40 mol%.

As the structural unit (a) having an acid labile group in the resin (A1), the structural unit (a1-0), the structural unit (a1-1), the structural unit (a1-2) and the structural unit (a1-5). At least one selected from the group consisting of), more preferably at least two or more, a combination of structural unit (a1-1) and structural unit (a1-2), structural unit (a1-1) and structural unit ( a1-5), structural unit (a1-1) and structural unit (a1-0), structural unit (a1-2) and structural unit (a1-0), structural unit (a1-5) And a combination of structural units (a1-0), structural units (a1-0), combinations of structural units (a1-1) and structural units (a1-2), structural units (a1-0), structural units (a1- The combination of 1) and the structural unit (a1-5) is more preferable, and the combination of the structural unit (a1-1) and the structural unit (a1-2) is even more preferable.

<Structural unit having no acid labile group>
The structural unit (s) is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “monomer (s)”). Examples of the monomer (s) include monomers that do not have an acid labile group known in the resist field. A preferred structural unit is a structural unit having a hydroxy group or a lactone ring and having no acid labile group. A structure unit having a hydroxy group and not having an acid labile group (hereinafter sometimes referred to as "structural unit (a2)") and/or a lactone ring and having no acid labile group From a resist composition containing a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”), a resist pattern having improved resolution and adhesion to a substrate can be formed.

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

［式（ａ２−０）中、
Ｒ^ａ３０は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｒ^ａ３１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のアシル基、炭素数２〜４のアシルオキシ基、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。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^ａ３１は互いに同一であっても異なってもよい。］ Examples of the structural unit (a2) having a phenolic hydroxy group include a structural unit represented by the formula (a2-0) (hereinafter sometimes referred to as “structural unit (a2-0)”).

[In the formula (a2-0),
R ^a30 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a31 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 acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
ma represents the integer of 0-4. When ma is an integer greater than or equal to 2, some R ^<a31 > may be mutually same or different. ]

^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom of R ^a30 include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1 , 1,2,2-Tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3 , 3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl group Group, an n-perfluorohexyl group and the like.
As R ^a30 , a hydrogen atom or an alkyl group having 1 to 4 carbon atoms is preferable, a hydrogen atom, a methyl group or an ethyl group is more preferable, and a hydrogen atom or a methyl group is further preferable.
^Examples of the alkoxy group of R ^a31 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group, and an alkoxy group having 1 to 4 carbon atoms is preferable, and a methoxy group or an ethoxy group is more preferable. A methoxy group is more preferable.
As ma, 0, 1 or 2 is preferable, 0 or 1 is more preferable, and 0 is further preferable.

Examples of the monomer that derives the structural unit (a2-0) include the monomers described in JP 2010-204634 A.
Among them, the structural unit (a2-0) is represented by the formula (a2-0-1), the formula (a2-0-2), the formula (a2-0-3) and the formula (a2-0-4). Embedded image is preferable, and the structural unit represented by formula (a2-0-1) or formula (a2-0-2) is more preferable.

The resin (A1) containing the structural unit (a2-0) undergoes a polymerization reaction using a monomer in which the phenolic hydroxy group of the monomer that induces the structural unit (a2-0) is protected by a protecting group, and then deprotected. It can be produced by processing. However, it is necessary to perform the deprotection treatment so that the acid labile group contained in the structural unit (a1) is not significantly impaired. An acetyl group etc. are mentioned as such a protective group.

When the resin (A1) has a structural unit (a2-0) having a phenolic hydroxy group, its content is 5 to 95 mol% based on the total of all structural units of the resin (A1). Is preferable, 10-80 mol% is more preferable, and 15-80 mol% is further preferable.

［式（ａ２−１）中、
Ｌ^ａ３は、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ２−ＣＯ−Ｏ−を表し、
ｋ２は１〜７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、互いに独立に、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 sometimes referred to as “structural unit (a2-1)”).

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

In formula (a2-1), L ^a3 is preferably —O—, —O—(CH ₂ ) _f1 —CO—O— (where f1 is an integer of 1 to 4), and more preferably -O-.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

Examples of the monomer that induces the structural unit (a2-1) include the monomers described in JP2010-204646A. The monomer represented by any of the formulas (a2-1-1) to (a2-1-6) is preferable, and the monomer represented by any of the formulas (a2-1-1) to (a2-1-4) is represented. Is more preferable, and the monomer represented by formula (a2-1-1) or formula (a2-1-3) is still more preferable.

When the resin (A1) contains the structural unit (a2-1), its content is usually 1 to 45 mol%, preferably 1 to 40 mol, based on the total of all structural units of the resin (A1). %, more preferably 1 to 35 mol %, further preferably 2 to 20 mol %.

<Structural unit (a3)>
The lactone ring contained in the structural unit (a3) may be a single ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. But it's okay. Preferably, a bridged ring having a γ-butyrolactone ring, an adamantane lactone ring or a γ-butyrolactone ring structure is used.

［式（ａ３−１）中、
Ｌ^ａ４は、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７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の整数を表す。ｐ１が２以上のとき、複数のＲ^ａ２１は互いに同一であっても異なってもよい。
式（ａ３−２）中、
Ｌ^ａ５は、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７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の整数を表す。ｑ１が２以上のとき、複数のＲ^ａ２２は互いに同一であっても異なってもよい。
式（ａ３−３）中、
Ｌ^ａ６は、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７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の整数を表す。ｒ１が２以上のとき、複数のＲ^ａ２３は互いに同一であっても異なってもよい。
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、＊−Ｏ−、＊−Ｏ−Ｌ^ａ８−Ｏ−、＊−Ｏ−Ｌ^ａ８−ＣＯ−Ｏ−、＊−Ｏ−Ｌ^ａ８−ＣＯ−Ｏ−Ｌ^ａ９−ＣＯ−Ｏ−又は＊−Ｏ−Ｌ^ａ８−Ｏ−ＣＯ−Ｌ^ａ９−Ｏ−を表す。
＊は、カルボニル基との結合手を表す。
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。
ｗ１は、０〜８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。］ The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3) or the formula (a3-4). These may be contained alone or in combination of two or more.

[In the formula (a3-1),
L ^a4 represents -O- or _{* -O- (CH 2) k3 -CO} -O- (k3 represents. An integer of 1-7) is represented by the group. * Represents a bond with the 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 the integer of 0-5. When p1 is 2 or more, a plurality of R ^a21 may be the same or different.
In formula (a3-2),
L ^a5 represents a group represented by —O— or *—O—(CH ₂ ) _k3— CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with the 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 an integer of 0 to 3. When q1 is 2 or more, a plurality of R ^a22 may be the same as or different from each other.
In formula (a3-3),
L ^a6 represents a group represented by —O— or *—O—(CH ₂ ) _k3— CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with the 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 an integer of 0 to 3. When r1 is 2 or more, a plurality of R ^a23 may be the same as or different from each other.
In formula (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 represents a single ^{bond, * -O-, * -O -L a8} -O -, * -O -L a8 -CO-O -, * -O -L a8 -CO-O-L a9 -CO- Represents O- or * -O- ^La8- O-CO- ^La9- O-.
* Represents a bond with the carbonyl group.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms.
w1 represents an integer of 0 to 8. When w1 is 2 or more, a plurality of R ^a25 may be the same as or different from each other. ]

Examples of the aliphatic hydrocarbon group of R ^a21 , R ^a22, and R ^a23 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group.
Examples of the halogen atom of R ^a24 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
^Examples of the alkyl group for 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. Of these, 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 of R ^a24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluoro. Hexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group and the like can be mentioned.

^Examples of the alkanediyl group of L ^a8 and L ^a9 include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5. -Diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, Examples thereof include 4-diyl group and 2-methylbutane-1,4-diyl group.

In formulas (a3-1) to (a3-3), L ^{a4 to} L ^a6 are independently of each other, preferably —O—, or k3 is an integer of 1 to 4 *—O—(CH ₂ ). a _k3 -CO-O-group represented by, more preferably -O- _{and, * - O-CH 2 -CO} -O- and, still more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are independently of each other, preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are independently of each other, preferably an integer of 0 to 2, and more preferably 0 or 1.

In formula (a3-4),
R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and further preferably a hydrogen atom or a methyl group.
L ^a7 is preferably a single bond, * - O-or * -O ^-L a8 -CO-O-, more preferably an a single _{bond, * -O -, * -CH 2} -CO-O- or * -C ₂ H ₄ is -CO-O-.

Examples of the monomer that leads to the structural unit (a3) include the monomer described in JP2010-204646A, the monomer described in JP2000-122294A, and the monomer described in JP2012-41274A. Can be mentioned. As the structural unit (a3), formula (a3-1-1) to formula (a3-1-6), formula (a3-2-1) to formula (a3-2-4), formula (a3-3-). 1) to the formula (a3-3-4) and the formula (a3-4-1) to the formula (a3-4-6), the structural unit represented by any of the formulas (a3-1-1), It is represented by any one of formula (a3-1-2) and formula (a3-2-3) to formula (a3-2-4) and formula (a3-4-1) to formula (a3-4-2). The structural unit represented by the formula (a3-1-1), the formula (a3-2-3) or the formula (a3-4-2) is further preferable.

In the structural units below, a compound in which a methyl group corresponding to R ^a24 is replaced with a hydrogen atom can also be mentioned as a specific example of the structural unit (a3-4).

When the resin (A1) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol%, preferably 10 to 65 mol% with respect to the total of all structural units of the resin (A1). And more preferably 10 to 60 mol %.
Further, the content rates of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3) and the structural unit (a3-4) are independent of each other, and the total structural units of the resin (A1) are the same. Is preferably 5 to 60 mol %, more preferably 5 to 50 mol %, and further preferably 10 to 50 mol %.

<Other structural units (t)>
As the structural unit (t), in addition to the structural unit (a2) and the structural unit (a3), a structural unit which may have a fluorine atom (hereinafter, referred to as “structural unit (a4)” depending on the case. (Excluding (a4-0)) and a structural unit (s) having a non-eliminating hydrocarbon group (hereinafter sometimes referred to as “structural unit (a5)”) and the like.

［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−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
Ａ^ａ４１は、置換基を有していてもよい炭素数１〜６のアルカンジイル基又は式（ａ−ｇ１）で表される基を表す。］

［式（ａ−ｇ１）中、
ｓは０又は１を表す。
Ａ^ａ４２及びＡ^ａ４４は、互いに独立に、置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基を表す。
Ａ^ａ４３は、単結合又は置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基を表す。
Ｘ^ａ４１及びＸ^ａ４２は、互いに独立に、−Ｏ−、−ＣＯ−、−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−を表す。
ただし、Ａ^ａ４２、Ａ^ａ４３、Ａ^ａ４４、Ｘ^ａ４１及びＸ^ａ４２の炭素数の合計は７以下である。
＊で表される２つの結合手のうち、右側の＊が−Ｏ−ＣＯ−Ｒ^ａ４２との結合手である。］ Examples of the structural unit (a4) include structural units represented by the formula (a4-1).

[In the formula (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 ^optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (a-g1). ]

[In the formula (a-g1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a single bond or an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
X ^a41 and X ^a42 each independently represent —O—, —CO—, ^—CO —O—, or —O—CO—.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41, and X ^a42 is 7 or less.
Of the two bonds represented by *, the * on the right side is a bond with -O-CO- ^Ra42 . ]

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

Examples of the chain type aliphatic hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group and an n-decyl group. Group, n-dodecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group and n-octadecyl group. Examples of the cyclic aliphatic hydrocarbon group include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and other cycloalkyl groups; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* is a bond And a polycyclic alicyclic hydrocarbon group such as.

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

［式（ａ−ｇ３）中、
Ｘ^ａ４３は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^ａ４５は、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。
＊は結合手を表す。］ ^Examples of the substituent of R ^a42 include a halogen atom or a group represented by the formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a fluorine atom.

[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents an aliphatic hydrocarbon group having at least one halogen atom and having 1 to 17 carbon atoms.
* Represents a bond. ]

^As the aliphatic hydrocarbon group for A ^a45, the same groups as those exemplified for R ^a42 can be mentioned.

R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, and an aliphatic hydrocarbon group which has an alkyl group having a halogen atom and/or a group represented by the formula (a-g3). Is more preferable.
When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, an aliphatic hydrocarbon group having a fluorine atom is preferable, a perfluoroalkyl group or a perfluorocycloalkyl group is more preferable, and a perfluoroalkyl group having 1 to 6 carbon atoms. Is more preferable, and a perfluoroalkyl group having 1 to 3 carbon atoms is particularly preferable. 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 and the like.
When R ^a42 is an aliphatic hydrocarbon group having a group represented by formula (a-g3), the aliphatic hydrocarbon including the carbon number contained in the group represented by formula (a-g3) The total carbon number of the group is preferably 15 or less, more preferably 12 or less. When the group represented by formula (a-g3) has a substituent, the number thereof is preferably 1.

［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 group having a group represented by formula (a-g3) is more preferably a group represented by formula (a-g2).

[In the formula (a-g2),
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 the carbonyl group. ]

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

The preferable structure represented by *-A ^a46 -X ^a44 -A ^a47 is the following structure.

^Examples of the alkanediyl group of A ^a41 include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group. A linear alkanediyl group such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, Examples 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 group of A ^{a42 to} A ^a44 in the group (a-g1) may have a carbon-carbon unsaturated bond, but an aliphatic saturated hydrocarbon group is preferable. As the aliphatic saturated hydrocarbon group, an alkyl group (the alkyl group may be linear or branched) and an alicyclic hydrocarbon group, and an alkyl group and an alicyclic hydrocarbon group are combined. And an aliphatic hydrocarbon group formed by the above. Specifically, a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, Examples thereof include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
^Examples of the substituent of the aliphatic hydrocarbon group of A ^{a42 to} A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
s is preferably 0.

^Examples of the group (a-g1) in which X ^a42 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group include the following groups. In the following examples, * and ** each represent a bond, and ** is a bond with -O-CO-Ra ⁴² .

［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), structural units represented by the formula (a4-2) and the formula (a4-3) are preferable.

[In the formula (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 a fluorine atom and having 1 to 10 carbon atoms. ]

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, a pentane-1,5-diyl group. , A linear alkanediyl group such as hexane-1,6-diyl group; 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 group formed by a chain structure, a ring structure and a combination thereof. The aliphatic hydrocarbon group is preferably an alkyl group or an alicyclic hydrocarbon group.
Examples of the alkyl group 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 And an ethylhexyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Can be mentioned. 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, 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.
Examples of the alkyl group having a fluorine atom include difluoromethyl group, trifluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 1 , 1,2,2-Tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1-(trifluoromethyl)-1,2,2,2- Tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl group, 1-(trifluoromethyl)-2,2,2-trifluoroethyl group, perfluorobutyl group, 1,1-bis(trifluoro)methyl-2,2,2- Trifluoroethyl group, 2-(perfluoropropyl)ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3 , 4,4,5,5-decafluoropentyl group, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl group, 2-(perfluorobutyl)ethyl group, 1 , 1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluoro Examples thereof include fluorinated alkyl groups such as hexyl group, perfluoropentylmethyl group and perfluorohexyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom include fluorinated cycloalkyl groups such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

［式（ａ４−３）中、
Ｒ^ｆ１１は、水素原子又はメチル基を表す。
Ａ^ｆ１１は、炭素数１〜６のアルカンジイル基を表す。
Ａ^ｆ１３は、フッ素原子を有していてもよい炭素数１〜１８の脂肪族炭化水素基を表す。
Ｘ^ｆ１２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^ｆ１４は、フッ素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^ｆ１３及びＡ^ｆ１４の少なくとも１つは、フッ素原子を有する脂肪族炭化水素基を表す。］ As A ^f1 in the formula (a4-2), an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.
As R ^f1 , a fluorinated alkyl group having 1 to 6 carbon atoms is preferable.

[In the formula (a4-3),
R ^f11 represents a hydrogen atom or a methyl group.
A ^f11 represents an alkanediyl group having 1 to 6 carbon atoms.
A ^f13 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a fluorine atom.
X ^f12 represents a carbonyloxy group or an oxycarbonyl group.
A ^f14 represents an aliphatic hydrocarbon group which may have a fluorine atom and has 1 to 17 carbon atoms.
However, at least one of A ^f13 and A ^f14 represents an aliphatic hydrocarbon group having a fluorine atom. ]

^Examples of the alkanediyl group of A ^f11 include the same groups as the alkanediyl group of A ^f1 .

The aliphatic hydrocarbon group for A ^f13 includes a chain and cyclic aliphatic hydrocarbon group, and a divalent aliphatic hydrocarbon group formed by combining these. This aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f13 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group. To be
Examples of the divalent chain aliphatic hydrocarbon group which may have a fluorine atom include an alkanediyl group such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group and a pentanediyl group; a difluoromethylene group, a perfluoroethylene group. And perfluoroalkanediyl groups such as a group, a perfluoropropanediyl group, a perfluorobutanediyl group and a perfluoropentanediyl group.
The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either a monocyclic group or a polycyclic group. Examples of the monocyclic aliphatic hydrocarbon group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic divalent aliphatic hydrocarbon group include an adamantanediyl group, a norbornanediyl group and a perfluoroadamantanediyl group.

The aliphatic hydrocarbon group for A ^f14 includes any of a chain type and a cyclic type, and an aliphatic hydrocarbon group formed by combining these. This aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f14 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom.
Examples of the chain aliphatic hydrocarbon group which may have a fluorine atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 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, Examples thereof include a heptyl group, a perfluoroheptyl group, an octyl group, and a perfluorooctyl group.
The cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the group containing a monocyclic aliphatic hydrocarbon group include a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group and a perfluorocyclohexyl group. Examples of the group containing a polycyclic aliphatic hydrocarbon group include an adamantyl group, an adamantylmethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, a perfluoroadamantylmethyl group and the like.

In the formula ^{(a4-3), A f11} is preferably an ethylene group.
The aliphatic hydrocarbon group for A ^f13 is preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms, and more preferably an aliphatic hydrocarbon group having 2 to 3 carbon atoms.
As the aliphatic hydrocarbon group of A ^f14, an aliphatic hydrocarbon group having 3 to 12 carbon atoms is preferable, and an aliphatic hydrocarbon group having 3 to 10 carbon atoms is more preferable. Among them, A ^f14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group.

Examples of the structural unit represented by the formula (a4-2) include structural units represented by the formula (a4-1-1) to the formula (a4-1-22).

Examples of the structural unit represented by the formula (a4-3) include structural units represented by the formulas (a4-1'-1) to (a4-1'-22).

［式（ａ４−４）中、
Ｒ^ｆ２１は、水素原子又はメチル基を表す。
Ａ^ｆ２１は、−（ＣＨ_２）_ｊ１−、−（ＣＨ_２）_ｊ２−Ｏ−（ＣＨ_２）_ｊ３−又は−（ＣＨ_２）_ｊ４−ＣＯ−Ｏ−（ＣＨ_２）_ｊ５−を表す。
ｊ１〜ｊ５は、互いに独立に、１〜６の整数を表す。
Ｒ^ｆ２２は、フッ素原子を有する炭素数１〜１０の炭化水素基を表す。］ The structural unit (a4) also includes a structural unit represented by the formula (a4-4).

[In the formula (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 _{is, - (CH 2) j1 -} , - (CH 2) j2 -O- (CH 2) j3 - or _{- (CH 2) j4 -CO-} O- (CH 2) j5 - represents a.
j1 to j5 each independently represent an integer of 1 to 6.
R ^f22 represents a C 1-10 hydrocarbon group having a fluorine atom. ]

^Examples of the hydrocarbon group having a fluorine atom of R ^f22 include the same as the hydrocarbon group of R ^f2 in the formula (a4-2). R ^f22 is preferably a ^C 1-10 alkyl group having a fluorine atom or a C 1-10 alicyclic hydrocarbon group having a fluorine atom, and a C 1-10 alkyl having a fluorine atom. A group is more preferable, and a C 1-6 alkyl group having a fluorine atom is further preferable.

In formula ^(A4-4), as the _{^{A f21, - (CH 2)}} j1 - , more preferably an ethylene group or a methylene group, more preferably a methylene group.

Examples of the structural unit represented by the formula (a4-4) include the following structural units.

When the resin (A1) has the structural unit (a4), its content is preferably 1 to 20 mol %, and 2 to 15 mol% based on the total of all structural units of the resin (A1). Is more preferable, and 3 to 10 mol% is further preferable.

［式（ａ５−１）中、
Ｒ^５１は、水素原子又はメチル基を表す。
Ｒ^５２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又はヒドロキシ基で置換されていてもよい。但し、Ｌ^５５との結合位置にある炭素原子に結合する水素原子は、炭素数１〜８の脂肪族炭化水素基で置換されない。
Ｌ^５５は、単結合又は炭素数１〜１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］ Examples of the non-eliminating hydrocarbon group contained in the structural unit (a5) include linear, branched or cyclic hydrocarbon groups. Among them, the structural unit (a5) is preferably a group containing an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include structural units represented by the formula (a5-1).

[In the formula (a5-1),
R ⁵¹ represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a hydroxy group. May be. However, the hydrogen atom bonded to the carbon atom at the bonding position with L ⁵⁵ is not substituted with the aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

The alicyclic hydrocarbon group for R ⁵² may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group.
The aliphatic hydrocarbon group having 1 to 8 carbon atoms includes, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Examples thereof include alkyl groups such as octyl group and 2-ethylhexyl group.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-hydroxyadamantyl group and 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 for L ⁵¹ include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and preferably a divalent aliphatic saturated hydrocarbon group. To be
Examples of the divalent saturated aliphatic hydrocarbon group include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group.
The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

［式（Ｌ１−１）中、
Ｘ^ｘ１は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ｌ^ｘ１は、炭素数１〜１６の２価の脂肪族飽和炭化水素基を表す。
Ｌ^ｘ２は、単結合又は炭素数１〜１５の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^ｘ１及びＬ^ｘ２の合計炭素数は、１６以下である。
式（Ｌ１−２）中、
Ｌ^ｘ３は、炭素数１〜１７の２価の脂肪族飽和炭化水素基を表す。
Ｌ^ｘ４は、単結合又は炭素数１〜１６の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^ｘ３及びＬ^ｘ４の合計炭素数は、１７以下である。
式（Ｌ１−３）中、
Ｌ^ｘ５は、炭素数１〜１５の２価の脂肪族飽和炭化水素基を表す。
Ｌ^ｘ６及びＬ^ｘ７は、互いに独立に、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^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 formula (L1-1) to formula (L1-4). In the following formula, * represents a bond with an oxygen atom.

[In the 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 carbon number of L ^x1 and L ^x2 is 16 or less.
In formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x3 and L ^x4 is 17 or less.
In formula (L1-3),
L ^x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of L ^{x5 to} L ^x7 is 15 or less.
In formula (L1-4),
L ^x8 and L ^x9 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total carbon number of L ^x8 , L ^x9, and W ^x1 is 15 or less. ]

L ^x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, 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 saturated aliphatic hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group.
L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.
L ^x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.
W ^x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, and more preferably a cyclohexanediyl group or an adamantanediyl group.

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

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

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

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

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

Examples of the structural unit (a5-1) include the followings.

In formulas (a5-1-1) to (a5-1-18), a structural unit in which a methyl group corresponding to R ⁵¹ is replaced with a hydrogen atom may be mentioned as a specific example of the structural unit (a5-1). it can.

When the resin (A1) has the structural unit (a5), its content is preferably 1 to 30 mol% and preferably 2 to 20 mol% based on the total of all structural units of the resin (A1). Is more preferable, and 3 to 15 mol% is further preferable.

The resin (A1) is preferably a resin composed of a structural unit (a4-0), a structural unit (a1) and a structural unit (s), that is, a monomer (a4-0), a monomer (a1) and a monomer (s). It is a copolymer with.
The structural unit (a1) is preferably the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group).
The structural unit (s) is preferably at least one of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably a structural unit represented by the formula (a2-1). The structural unit (a3) is preferably at least one of the structural unit represented by the formula (a3-1), the structural unit represented by the formula (a3-2) and the structural unit represented by the formula (a3-4).

The resin (A1) contains a structural unit derived from a monomer having an adamantyl group (particularly, the structural unit (a1-1)) in an amount of 15 mol% or more based on the content of the structural unit (a1). preferable. When the content of the structural unit having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

Each structural unit constituting the resin (A1) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that induces these structural units. can do. The content rate of each structural unit which resin (A1) has can be adjusted with the usage-amount of the monomer used for superposition|polymerization.
The weight average molecular weight of the resin (A1) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, further preferably). 15,000 or less).
In the present specification, the weight average molecular weight is a value obtained by gel permeation chromatography. Gel permeation chromatography can be measured under the analysis conditions described in the examples.

<Resin (A2)>
As the resin (A2) containing a structural unit having a fluorine atom and not containing a structural unit having an acid labile group, a resin containing the structural unit (a4-0) or the structural unit (a4) is preferable. In the resin (A2), the content of the structural unit (a4-0) or the structural unit (a4) is preferably 40 mol% or more, and 45 mol% with respect to the total of all structural units of the resin (A2). % Or more, and more preferably 50 mol% or more.
Examples of the structural unit that the resin (A2) may further have include the structural unit (a2), the structural unit (a3), the structural unit (a5) and structural units well known in the art.
The weight average molecular weight of the resin (A2) is preferably 5,000 or more (more preferably 6,000 or more) and 80,000 or less (more preferably 60,000 or less).
When the resist composition of the present invention contains the resin (A2), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, relative to 100 parts by mass of the resin (A1). %, more preferably 2 to 40 parts by mass, and particularly preferably 2 to 30 parts by mass.

The total content of the resin (A1) and the resin (A2) is preferably 80% by mass or more and 99% by mass or less based on the solid content of the resist composition. The solid content of the resist composition and the resin content relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

<Acid generator (B)>
The acid generator generates an acid upon exposure to light, and the generated acid acts as a catalyst to eliminate a group that is eliminated by the acid of the resin (A). The acid generator is classified into a nonionic type and an ionic type, and any one may be used in the acid generator (B) of the resist composition of the present invention.
Examples of the nonionic acid generator include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4) -Sulfonate), sulfones (eg, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) and the like. Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

Examples of the acid generator (B) include JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, and JP-A-63-163452. JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent 3914407, European Patent 126,712. The compounds capable of generating an acid by the radiation described in etc. can be used. Moreover, you may use the compound manufactured by the well-known method.

［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１価の脂環式炭化水素基を表し、該メチル基及び該１価の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, more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”).

[In the formula (B1),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the methyl group and the monovalent it is, -O - - -CH ₂ contained in the alicyclic hydrocarbon group, - SO ₂ - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]

The perfluoroalkyl group of Q ¹ and Q ² includes a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group and a perfluoroalkyl group. Hexyl group and the like can be mentioned.
Q ¹ and Q ² are preferably, independently of each other, a fluorine atom or a trifluoromethyl group, and more preferably both are a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and 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, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group , Straight chain such as 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 An alkanediyl group;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- A branched alkanediyl group such as a 1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, a 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 and the like. Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group and adamantane-2,6-diyl group Groups and the like.

［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。］ Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced with —O— or —CO— include, for example, any of formula (b1-1) to formula (b1-3). And a group represented by. In the formulas (b1-1) to (b1-3) and the following specific examples, * represents a bond with -Y.

[In the formula (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total carbon number of L ^b2 and L ^b3 is 22 or less.
In formula (b1-2),
L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total carbon number of L ^b4 and L ^b5 is 22 or less.
In formula (b1-3),
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total carbon number 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 replacement is the carbon number 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 represented by the formula (b1-1) or the formula (b1-3) is a group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO—. Is preferred.

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

[In the formula (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
In formula (b1-5),
L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total carbon number of L ^b9 and L ^b10 is 20 or less.
In formula (b1-6),
L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total carbon number of L ^b11 and L ^b12 is 21 or less.
In formula (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total carbon number of L ^{b13 to} L ^b15 is 19 or less.
In formula (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total carbon number of L ^{b16 to} L ^b18 is 19 or less. ]

L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, 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 formula (b1-3) include groups represented by formula (b1-9) to formula (b1-11).

[In formula (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and 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. 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 carbon number of L ^b19 and L ^b20 is 23 or less.
In formula (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and the hydrogen atom contained in the 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. May be. 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 carbon number of L ^{b21 to} L ^b23 is 21 or less.
In formula (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the 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. May be. 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 (b1-9) to (b1-11), when the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with an acyloxy group, the carbon number of the acyloxy group, CO in the ester bond, and The carbon number 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 and an adamantylcarbonyloxy group.
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), examples of the group represented by the formula (b1-4) include the following.

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

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

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

Among the groups represented by the formula (b1-1), examples of the group 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), examples of the group represented by the formula (b1-9) include the following.

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

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

Examples of the monovalent alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y11).
When —CH ₂ — contained in the monovalent alicyclic hydrocarbon group represented by Y is replaced by —O—, —SO ₂ — or —CO—, the number thereof may be 1 or 2 or more. There may be more than one. Examples of such a group include groups represented by formula (Y12) to formula (Y38).

That is, in Y, two hydrogen atoms contained in the alicyclic hydrocarbon group are respectively replaced by oxygen atoms, and the two oxygen atoms together with the alkanediyl group having 1 to 8 carbon atoms form a ketal ring. It may also have a structure in which oxygen atoms are bonded to different carbon atoms. However, in the case of forming a spiro ring represented by formula (Y28) to formula (Y33), the alkanediyl group between two oxygen atoms preferably has one or more fluorine atoms. Further, among the alkanediyl groups contained in the ketal structure, it is preferable that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

Among them, a group represented by any one of formula (Y1) to formula (Y20), formula (Y30) and formula (Y31) is preferable, and more preferably formula (Y11), formula (Y15) and formula (Y15). Y16), a formula (Y20), a formula (Y30) or a group represented by the formula (Y31), and more preferably a group represented by the formula (Y11), the formula (Y15) or the formula (Y30).

As the substituent of the methyl group represented by Y, a halogen atom, a hydroxy group, a monovalent alicyclic hydrocarbon group having 3 to 16 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, glycidyloxy group or a _{- (CH 2) ja -O-} CO-R b1 group ^{(wherein, R b1} represents an alkyl group having 1 to 16 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 16 carbon atoms Alternatively, it represents a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and ja represents an integer of 0 to 4) and the like.
As the substituent of the monovalent alicyclic hydrocarbon group represented by Y, a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and 3 carbon atoms To 16 monovalent alicyclic hydrocarbon group, C1 to C12 alkoxy group, C6 to C18 monovalent aromatic hydrocarbon group, C7 to C21 aralkyl group, and C2 4 acyl group, glycidyloxy group, or _{- (CH 2) ja -O-} CO-R b1 group ^{(wherein, R b1} represents an alkyl group having 1 to 16 carbon atoms, monovalent cycloaliphatic of 3 to 16 carbon atoms It represents a cyclic hydrocarbon group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and ja represents an integer of 0 to 4) and the like.

Examples of the hydroxy group-containing alkyl group include 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 monovalent aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group and mesityl group. Examples thereof include aryl groups such as groups, biphenyl groups, phenanthryl groups, 2,6-diethylphenyl groups, and 2-methyl-6-ethylphenyl groups.
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 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 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 is -CH ₂ - is preferably replaced by -O- or -CO-. In this case, -CH ₂ contained in the methyl group of Y - is not Okikawara by -O- or -CO-.

Y is preferably a monovalent 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. The methylene group constituting the group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group. Y is particularly preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group or a group represented by the following.

As the sulfonate anion in the salt represented by the formula (B1), an anion represented by the formula (B1-A-1) to the formula (B1-A-46) [hereinafter, anion (B1 -A-1)" or the like. ] Are preferable, Formula (B1-A-1)-Formula (B1-A-4), Formula (B1-A-9), Formula (B1-A-10), Formula (B1-A-24)-Formula The anion represented by any of (B1-A-33) and formula (B1-A-36) to formula (B1-A-40) is more preferable.

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. R ⁱ⁸ is, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. Is 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 sulfonate anion in the salt represented by the formula (B1) include the anions described in JP2010-204646A.

Preferred examples of the sulfonate anion in the salt represented by the formula (B1) include anions represented by the formulas (B1a-1) to (B1a-22).

Among them, formula (B1a-1) to formula (B1a-3) and formula (B1a-7) to formula (B1a-16), formula (B1a-18), formula (B1a-19), formula (B1a-22). Anion represented by any of (1) to (4) is preferable.

［式（ｂ２−１）〜式（ｂ２−４）において、
Ｒ^ｂ４〜Ｒ^ｂ６は、互いに独立に、炭素数１〜３０の１価の脂肪族炭化水素基、炭素数３〜３６の１価の脂環式炭化水素基又は炭素数６〜３６の１価の芳香族炭化水素基を表し、該１価の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１価の脂環式炭化水素基又は炭素数６〜１８の１価の芳香族炭化水素基で置換されていてもよく、該１価の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１価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１価の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、互いに独立に、ヒドロキシ基、炭素数１〜１２の１価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、互いに独立に、０〜５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、互いに独立に、炭素数１〜３６の１価の脂肪族炭化水素基又は炭素数３〜３６の１価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１価の脂肪族炭化水素基、炭素数３〜３６の１価の脂環式炭化水素基又は炭素数６〜１８の１価の芳香族炭化水素基を表す。
Ｒ^ｂ１２は、炭素数１〜１２の１価の脂肪族炭化水素基、炭素数３〜１８の１価の脂環式炭化水素基又は炭素数６〜１８の１価の芳香族炭化水素基を表し、該１価の脂肪族炭化水素基に含まれる水素原子は、炭素数６〜１８の１価の芳香族炭化水素基で置換されていてもよく、該１価の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、互いに独立に、ヒドロキシ基、炭素数１〜１２の１価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、互いに独立に、０〜５の整数を表す。
ｑ２及びｒ２は、互いに独立に、０〜４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。］ Examples of the Z ⁺ organic cation include an organic onium cation, for example, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, an organic phosphonium cation, and the like, preferably an organic sulfonium cation or an organic iodonium cation. And more preferably an arylsulfonium cation.
Z ⁺ in the formula (B1) is preferably a cation represented by any of the formulas (b2-1) to (b2-4) [hereinafter, “cation (b2-1)” depending on the formula number, etc. There is a case. ].

[In the formulas (b2-1) to (b2-4),
R ^{b4 to} R ^b6 are, independently of each other, a monovalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms, or a monovalent one having 6 to 36 carbon atoms. Represents an aromatic hydrocarbon group, and the hydrogen atom contained in the monovalent aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or a monovalent alicyclic carbon group having 3 to 12 carbon atoms. It may be substituted with a hydrogen group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the monovalent alicyclic hydrocarbon group is a halogen atom or 1 to 18 carbon atoms. May be substituted with a monovalent aliphatic hydrocarbon group, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group, and the hydrogen atom contained in the monovalent aromatic hydrocarbon group may be a halogen atom or a hydroxy group. It may be substituted with a 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 bound, and —CH ₂ — contained in the ring may be replaced with —O—, —SO— or —CO—. ..
R ^b7 and R ^b8 each independently represent a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 represent the integer of 0-5 mutually independently.
When m2 is 2 or more, a plurality of R ^b7 may be the same or different, and when n2 is 2 or more, a plurality of R ^b8 may be the same or different.
R ^b9 and R ^b10 independently of each other represent a monovalent aliphatic hydrocarbon group having 1 to 36 carbon atoms or a monovalent 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 bound, and —CH ₂ — contained in the ring may be replaced with —O—, —SO— or —CO—. ..
R ^b11 represents a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 36 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms, or a monovalent aromatic carbon group having 6 to 18 carbon atoms. Represents a hydrogen group.
R ^b12 is a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the monovalent aliphatic hydrocarbon group may be substituted with a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. The contained hydrogen atom may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms.
R ^b11 and R ^b12 may be bonded together to form a ring containing —CH—CO—, and —CH ₂ — contained in the ring is —O—, —SO—. Alternatively, it may be replaced with -CO-.
R ^{b13 to} R ^b18 each independently represent a hydroxy group, a monovalent 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 represent the integer of 0-5 mutually independently.
q2 and r2 represent the integer of 0-4 independently of each other.
u2 represents 0 or 1.
When o2 is 2 or more, a plurality of R ^b13 may be the same or different, when p2 is 2 or more, a plurality of R ^b14 may be the same or different, and when q2 is 2 or more R ^b15 may be the same or different, when r2 is 2 or more, R ^b16 may be the same or different, and when s2 is 2 or more, R ^b17 is ^They may be the same or different, and when t2 is 2 or more, a plurality of R ^b18 may be the same or different. ]

Examples of the monovalent aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2 And an alkyl group of an ethylhexyl group. In particular, the monovalent aliphatic hydrocarbon group represented by R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
The monovalent alicyclic hydrocarbon group may be either monocyclic or polycyclic, and the monocyclic monovalent alicyclic hydrocarbon group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, Examples thereof include cycloalkyl groups such as cyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic monovalent alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups.

Particularly, the carbon number of the monovalent alicyclic hydrocarbon group of R ^{b9 to} R ^b12 is preferably 3 to 18, and more preferably 4 to 12.

Examples of the monovalent alicyclic hydrocarbon group having a hydrogen atom substituted with an aliphatic hydrocarbon group include, for example, a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, and a methylnorbornyl group. Group, isobornyl group and the like. In the monovalent alicyclic hydrocarbon group in which a hydrogen atom is substituted with a monovalent aliphatic hydrocarbon group, the total carbon number of the monovalent alicyclic hydrocarbon group and the monovalent aliphatic hydrocarbon group Is preferably 20 or less.

Examples of the monovalent aromatic hydrocarbon group include phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group and p- Examples of the aryl group include an adamantylphenyl group, a biphenylyl group, a naphthyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.
When the monovalent aromatic hydrocarbon group contains a monovalent aliphatic hydrocarbon group or a monovalent alicyclic hydrocarbon group, a monovalent aliphatic hydrocarbon group or carbon having 1 to 18 carbon atoms A monovalent alicyclic hydrocarbon group of the number 3 to 18 is preferable.
A p-methoxyphenyl group etc. are mentioned as a monovalent|monohydric aromatic hydrocarbon group by which the hydrogen atom was substituted by the alkoxy group.
Examples of the monovalent aliphatic hydrocarbon group having a hydrogen atom substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group and naphthylethyl group. ..

Examples of the alkoxy group include 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.
As the alkylcarbonyloxy group, a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentyl carbonyloxy group, a hexyl carbonyloxy group, an octyl carbonyloxy group and a 2-ethylhexyl carbonyloxy group.

The ring which R ^b4 and R ^b5 may form together with the sulfur atom to which they are bonded is a monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated ring. It may be. Examples of this ring include rings having 3 to 18 carbon atoms, and preferably rings 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 rings.

The ring formed by R ^b9 and R ^b10 together with the sulfur atom to which they are bonded may be a monocyclic ring, polycyclic ring, aromatic ring, non-aromatic ring, saturated ring or unsaturated ring. 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 thiolane-1-ium ring (tetrahydrothiophenium ring) and thian-1-ium. Ring, 1,4-oxathian-4-ium ring and the like.
The ring formed by R ^b11 and R ^{b12 taken} together may be any of a monocyclic ring, a polycyclic ring, an aromatic ring, a non-aromatic ring, a saturated ring and an unsaturated ring. 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. To be

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

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

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

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

The acid generator (B1) is a combination of the above-mentioned sulfonate anion and the above-mentioned organic cation, and these can be arbitrarily combined. The acid generator (B1) is preferably represented by any one of formula (B1a-1) to formula (B1a-3) and formula (B1a-7) to formula (B1a-19) and formula (B1a-22). And a cation (b2-1) or a cation (b2-3).

Examples of the acid generator (B1) preferably include those represented by formulas (B1-1) to (B1-40), among which formula (B1-1) and formula (B1) containing an arylsulfonium cation. -2), formula (B1-3), formula (B1-5), formula (B1-6), formula (B1-7), formula (B1-11), formula (B1-12), formula (B1- 13), formula (B1-14), formula (B1-17), formula (B1-20), formula (B1-21), formula (B1-23), formula (B1-24), formula (B1-25). ), formula (B1-26), formula (B1-29), formula (B1-31), formula (B1-32), formula (B1-33), formula (B1-34), formula (B1-35). , (B1-36), (B1-37), (B1-38), (B1-39), or (B1-40).

The content of the acid generator (B1) is preferably 30% by mass or more and 100% by mass or less, and more preferably 50% by mass or more and 100% by mass or less with respect to the total amount of the acid generator (B). It is more preferable that the acid generator (B1) is substantially used.
The content of the acid generator (B) is preferably 1 part by mass or more (more preferably 3 parts by mass), preferably 30 parts by mass or less (more preferably 25 parts by mass) with respect to 100 parts by mass of the resin (A). Part and below). The resist composition of the present invention may contain one kind of the acid generator (B) or may contain plural kinds thereof.

<Solvent (E)>
The content of the solvent (E) in the resist composition is usually 90% by mass or more, preferably 92% by mass or more, more preferably 94% by mass or more, and usually 99.9% by mass or less, preferably 99% by mass or less. Is. The content of the solvent (E) can be measured by a known analysis 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. And the like; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; The solvent (E) may contain 1 type independently and may contain 2 or more types.

<Quencher (C)>
Examples of the quencher (C) include salts that generate an acid having a weaker acidity than the acid generated from the basic nitrogen-containing organic compound or the acid generator (B).
Examples of basic nitrogen-containing organic compounds include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.

As amines, 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-,3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, Heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, tri Heptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, Ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, tri Isopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3 , 3'-Diethyldiphenylmethane, piperazine, morpholine, piperidine and hindered amine compounds having a piperidine skeleton described in JP-A-11-52575, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2- Di(2-pyridyl)ethane, 1,2-di(4-pyridyl)ethane, 1,2-di(2-pyridyl)ethene, 1,2-di(4-pyridyl)ethene, 1,3-di( 4-pyridyl)propane, 1,2-di(4-pyridyloxy)ethane, di(2-pyridyl)ketone, 4,4′-dipyridyl sulfide, 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine , 2,2′-dipicolylamine, bipyridine, and the like, preferably diisopropylaniline, and particularly preferably 2,6-diisopropylaniline.

Examples of ammonium salts include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethyl. Examples thereof include ammonium hydroxide, tetra-n-butylammonium salicylate and choline.

Examples of the salt that generates an acid having a lower acidity than the acid generated from the acid generator (B) include a salt represented by the following formula, a weak acid intramolecular salt represented by the formula (D), and JP-A No. 2012-2012. Salts described in JP-A-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502 and JP-A-2011-191745 can be mentioned. A weak acid inner salt represented by the formula (D) (hereinafter sometimes referred to as “weak acid inner salt (D)”) is preferable.
The acidity of a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B) is represented by an acid dissociation constant (pKa). The salt which generates an acid having a weaker acidity than the acid generated from the salt (I) and the acid generator (B) is a salt whose acid dissociation constant of the acid generated from the salt is usually -3<pKa, A salt of -1<pKa<7 is preferable, and a salt of 0<pKa<5 is more preferable.

［式（Ｄ）中、
Ｒ^Ｄ１及びＲ^Ｄ２は、互いに独立に、炭素数１〜１２の１価の炭化水素基、炭素数１〜６のアルコキシ基、炭素数２〜７のアシル基、炭素数２〜７のアシルオキシ基、炭素数２〜７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ’及びｎ’は、互いに独立に、０〜４の整数を表し、ｍ’が２以上の場合、複数のＲ^Ｄ１は同一であっても異なってもよく、ｎ’が２以上の場合、複数のＲ^Ｄ２は同一であっても異なってもよい。］

[In the formula (D),
R ^D1 and R ^D2 are, independently of each other, a monovalent hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, and an acyloxy group having 2 to 7 carbon atoms. Represents an alkoxycarbonyl group having 2 to 7 carbon atoms, a nitro group or a halogen atom.
m′ and n′ each independently represent an integer of 0 to 4, when m′ is 2 or more, a plurality of R ^D1 may be the same or different, and when n′ is 2 or more, A plurality of R ^D2 may be the same or different. ]

In the weak acid inner salt (D), as the hydrocarbon group of R ^D1 and R ^D2, a monovalent aliphatic hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group and The group etc. which are formed by combining these are mentioned.
Examples of the monovalent aliphatic hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group and nonyl group.
The monovalent alicyclic hydrocarbon group may be either monocyclic or polycyclic, and may be saturated or unsaturated. Examples thereof include cyclopropyl groups, cyclobutyl groups, cyclopentyl groups, cyclohexyl groups, cyclononyl groups, cycloalkyl groups such as cyclododecyl groups, norbornyl groups, adamantyl groups, and the like.
Examples of the monovalent aromatic hydrocarbon group include phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4- Propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-tert-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group And aryl groups such as cumenyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, and 2-methyl-6-ethylphenyl group.
The group formed by combining these includes an alkyl-cycloalkyl group, a cycloalkyl-alkyl group, an aralkyl group (for example, a phenylmethyl group, a 1-phenylethyl group, a 2-phenylethyl group, a 1-phenyl- group. 1-propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group etc.) and the like.

Examples of the alkoxy group include a methoxy group and an ethoxy group.
Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, a cyclohexanecarbonyl group and the like.
Examples of the acyloxy group include groups in which an oxy group (—O—) is bonded to the above acyl group.
Examples of the alkoxycarbonyl group include groups in which a carbonyl group (—CO—) is bonded to the above alkoxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom.

In the formula (D), R ^D1 and R ^D2 are independently of each other an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and 2 to 2 carbon atoms. An acyl group having 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group or a halogen atom is preferable.
m′ and n′ are each independently preferably an integer of 0 to 2, and more preferably 0. When m′ is 2 or more, the plurality of R ^D1 may be the same or different, and when n′ is 2 or more, the plurality of R ^D2 may be the same or different.

The weak acid inner salt (D) includes the following compounds.

The weak acid inner salt (D) can be produced by the method described in "Tetrahedron Vol. 45, No. 19, p6281-6296". As the weak acid inner salt (D), a commercially available compound can be used.

The content of the quencher (C) in the solid content of the resist composition 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. %.

<Other ingredients>
The resist composition may contain a component other than the above-mentioned components (hereinafter sometimes referred to as “other component (F)”), if necessary. As the other component (F), additives known in the resist field, for example, sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes and the like can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A1), an acid generator (B), and optionally a resin (A2), a solvent (E), a quencher (C) and other components (F). Can be prepared by mixing 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 kind of resin and the solubility of the resin in the solvent (E) and the like. As the mixing time, an appropriate time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing the respective components, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

[Method for manufacturing resist pattern]
The method for producing a resist pattern of the present invention is
(1) a step of applying the resist composition of the present invention onto a substrate,
(2) a step of drying the composition after coating to form a composition layer,
(3) a 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.

The resist composition can be applied onto the substrate by a commonly used apparatus such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers. The substrate may be washed before applying the resist composition, or an antireflection film or the like may be formed on the substrate.

The composition is dried to remove the solvent and form a composition layer. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called prebaking), or using a decompression device. The heating temperature is preferably 50 to 200° C., and the heating time is preferably 10 to 180 seconds. Moreover, the pressure at the time of drying under reduced pressure is preferably about 1 to 1.0×10 ⁵ Pa.

The obtained composition layer is usually exposed using an exposure device. The exposure machine may be an immersion exposure machine. Although various light sources can be used as the exposure light source, ArF excimer laser (wavelength 193 nm) is preferable. At the time of exposure, the exposure is usually performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, it may be exposed by direct drawing without using a mask.

The composition layer after exposure is subjected to heat treatment (so-called post-exposure bake) in order to accelerate the deprotection reaction at the acid labile group. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C.

The composition layer after heating is usually developed using a developing device 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 manufactured by selecting the type of developer as follows.

As the developing solution, a developing solution containing an organic solvent (hereinafter sometimes referred to as "organic developing solution") is preferable. By using an organic developer, a negative resist pattern can be produced from the resist composition of the present invention.
Examples of the organic solvent contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether. Examples include ether solvents; amide solvents such as N,N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and further preferably substantially only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and/or 2-heptanone. 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. More preferably, it is only butyl acetate and/or 2-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 a solvent of a different type from the organic developer.

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

[Use]
The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure. Yes, more preferable as a resist composition for electron beam (EB) exposure, a resist composition for ArF excimer laser exposure, or a resist composition for EUV exposure, and further suitable as a resist composition for ArF excimer laser exposure. Yes, it is useful for fine processing of semiconductors.

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

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

特開２００８−２０９９１７号公報に記載された方法によって得られた式（Ｂ１−２１−ｂ）で表される化合物３０．００部、式（Ｂ１−２１−ａ）で表される塩３５．５０部、クロロホルム１００部及びイオン交換水５０部を仕込み、２３℃で１５時間攪拌した。得られた反応液が２層に分離していたので、クロロホルム層を分液して取り出し、更に、このクロロホルム層にイオン交換水３０部を添加し、水洗した。この操作を５回繰り返した。クロロホルム層を濃縮し、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル１００部を加えて２３℃で３０分間攪拌し、ろ過することにより、式（Ｂ１−２１−ｃ）で表される塩４８．５７部を得た。 Synthesis Example 1 [Synthesis of Salt Represented by Formula (B1-21)]

30.00 parts of the compound represented by the formula (B1-21-b) obtained by the method described in JP 2008-209917 A, and the salt represented by the formula (B1-21 -a) 35.50. Parts, 100 parts of chloroform and 50 parts of ion-exchanged water were charged and stirred at 23° C. for 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 30 parts of ion-exchanged water was added to this chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 100 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23° C. for 30 minutes, and filtered to give the salt of the formula (B1-21-c) 48. 57 parts were obtained.

式（Ｂ１−２１−ｃ）で表される塩２０．００部、式（Ｂ１−２１−ｄ）で表される化合物２．８４部及びモノクロロベンゼン２５０部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．２１部を添加し、更に、１００℃で１時間攪拌した。得られた反応溶液を濃縮した。得られた残渣に、クロロホルム２００部及びイオン交換水５０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層にイオン交換水５０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮した。得られた残渣に、アセトニトリル５３．５１部に溶解し、濃縮し、ｔｅｒｔ−ブチルメチルエーテル１１３．０５部を加えて攪拌し、ろ過することにより、式（Ｂ１−２１）で表される塩１０．４７部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２３７．１
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３３９．１

20.00 parts of the salt represented by the formula (B1-21-c), 2.84 parts of the compound represented by the formula (B1-21-d) and 250 parts of monochlorobenzene were charged, and the mixture was stirred at 23°C for 30 minutes. .. 0.21 parts of copper(II) dibenzoate was added to the obtained mixed liquid, and the mixture was further stirred at 100° C. for 1 hour. The obtained reaction solution was concentrated. To the obtained residue, 200 parts of chloroform and 50 parts of ion-exchanged water were added, stirred at 23° C. for 30 minutes, separated, and the organic layer was taken out. 50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23° C. for 30 minutes, separated, and the organic layer was taken out. This water washing operation was repeated 5 times. The obtained organic layer was concentrated. The salt thus obtained was dissolved in 53.51 parts of acetonitrile, concentrated, added with 113.05 parts of tert-butyl methyl ether, stirred, and filtered to obtain the salt 10 represented by the formula (B1-21). We obtained 0.47 parts.
MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 339.1

式（Ｂ１−２２−ａ）で表される塩１１．２６部、式（Ｂ１−２２−ｂ）で表される化合物１０．００部、クロロホルム５０部及びイオン交換水２５部を仕込み、２３℃で１５時間攪拌した。得られた反応液が２層に分離していたので、クロロホルム層を分液して取り出し、更に、該クロロホルム層にイオン交換水１５部を添加し、水洗した。この操作を５回繰り返した。クロロホルム層を濃縮し、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて２３℃で３０分間攪拌し、ろ過することにより、式（Ｂ１−２２−ｃ）で表される塩１１．７５部を得た。 Synthesis Example 2 [Synthesis of Salt Represented by Formula (B1-22)]

11.26 parts of the salt represented by the formula (B1-22-a), 10.00 parts of the compound represented by the formula (B1-22-b), 50 parts of chloroform and 25 parts of deionized water were charged, and the temperature was 23°C. It was stirred for 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23° C. for 30 minutes, and filtered to obtain the salt represented by the formula (B1-22-c). Obtained 75 parts.

式（Ｂ１−２２−ｃ）で表される塩１１．７１部、式（Ｂ１−２２−ｄ）で表される化合物１．７０部及びモノクロロベンゼン４６．８４部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．１２部を添加し、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮した。得られた残渣に、クロロホルム５０部及びイオン交換水１２．５０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層にイオン交換水１２．５０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この水洗操作を８回繰り返した。得られた有機層を濃縮した。得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて攪拌し、ろ過することにより、式（Ｂ１−２２）で表される塩６．８４部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２３７．１
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３２３．０

11.71 parts of the salt represented by the formula (B1-22-c), 1.70 parts of the compound represented by the formula (B1-22-d) and 46.84 parts of monochlorobenzene were charged, and the mixture was kept at 23° C. for 30 minutes. It was stirred. 0.12 parts of copper(II) dibenzoate was added to the obtained mixed liquid, and the mixture was further stirred at 100° C. for 30 minutes. The obtained reaction solution was concentrated. Chloroform (50 parts) and ion-exchanged water (12.50 parts) were added to the obtained residue, and the mixture was stirred at 23° C. for 30 minutes, separated, and the organic layer was taken out. 12.50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23° C. for 30 minutes, separated, and the organic layer was taken out. This water washing operation was repeated 8 times. The obtained organic layer was concentrated. To the obtained residue, 50 parts of tert-butyl methyl ether was added, stirred and filtered to obtain 6.84 parts of a salt represented by the formula (B1-22).
MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 323.0

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

Hereinafter, these monomers are referred to as “monomer (a1-1-1)” and the like according to the formula numbers.

Synthesis Example 3 [Synthesis of Resin A1-1]
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 monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-9):monomer (a2-1-1):monomer (a3-4-2):monomer (a4-0-3)] is The mixture was mixed at a ratio of 18.5:18.5:5.5:55:2.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-1 having a weight average molecular weight of 7.8×10 ³ with a yield of 68%. This resin A1-1 has the following structural units.

Synthesis Example 4 [Synthesis of Resin A1-2]
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 monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-9):monomer (a2-1-1):monomer (a3-4-2):monomer (a4-0-3)] is The mixture was mixed so as to be 18.5:18.5:4.5:54:4.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 mass times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-2 having a weight average molecular weight of 7.8×10 ³ with a yield of 70%. This resin A1-2 has the following structural units.

Synthesis Example 5 [Synthesis of Resin A1-3]
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 monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-9):monomer (a2-1-1):monomer (a3-4-2):monomer (a4-0-3)] is The mixture was mixed so as to be 20:20:4.5:48:7.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-3 having a weight average molecular weight of 7.8×10 ³ with a yield of 66%. This resin A1-3 has the following structural units.

Synthesis Example 6 [Synthesis of Resin A1-4]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a3-2-1), a monomer (a3-4-2) and a monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-9):monomer (a3-2-1):monomer (a3-4-2):monomer (a4-0-3)] is The mixture was mixed so as to be 18.5:18.5:10:50:3, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-4 having a weight average molecular weight of 6.9×10 ³ with a yield of 70%. This resin A1-4 has the following structural units.

Synthesis Example 7 [Synthesis of Resin A1-5]
As the monomer, a monomer (a1-1-2), a monomer (a3-4-2) and a monomer (a4-0-3) were used, and the molar ratio thereof was [monomer (a1-1-2):monomer (a3-4). -2): Monomer (a4-0-3)] was mixed so as to be 40:55:5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-5 having a weight average molecular weight of 7.9×10 ³ with a yield of 70%. This resin A1-5 has the following structural units.

Synthesis Example 8 [Synthesis of Resin A1-6]
As the monomer, a monomer (a1-1-2), a monomer (a3-2-1) and a monomer (a4-0-3) were used, and the molar ratio thereof was [monomer (a1-1-2):monomer (a3-2). -1): Monomer (a4-0-3)] was mixed so as to be 40:55:5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to give a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-6 having a weight average molecular weight of 7.6×10 ³ with a yield of 68%. This resin A1-6 has the following structural units.

Synthesis Example 9 [Synthesis of Resin A1-7]
As the monomer, a monomer (a1-1-1), a monomer (a2-1-x), a monomer (a3-4-2) and a monomer (a4-0-3) are used, and the molar ratio thereof is [monomer (a1-1 -1): Monomer (a2-1-x): Monomer (a3-4-2): Monomer (a4-0-3)] are mixed so as to be 35:5:55:5, and the total amount of monomers is 1.5 times by mass propylene glycol monomethyl ether acetate was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain a resin A1-7 having a weight average molecular weight of 7.5×10 ³ with a yield of 64%. This resin A1-7 has the following structural units.

Synthesis Example 10 [Synthesis of Resin A1-8]
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 monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-9):monomer (a2-1-1):monomer (a3-4-2):monomer (a4-0-3)] is The mixture was mixed so as to be 20:20:2.5:48:9.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 mass times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-8 having a weight average molecular weight of 7.4×10 ³ with a yield of 67%. This resin A1-8 has the following structural units.

Synthesis Example 11 [Synthesis of Resin A1-9]
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 monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-11):monomer (a2-1-1):monomer (a3-4-2):monomer (a4-0-3)] is The mixture was mixed at a ratio of 18.5:18.5:5.5:55:2.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain a resin A1-9 having a weight average molecular weight of 7.7×10 ³ with a yield of 64%. This resin A1-9 has the following structural units.

Synthesis Example 12 [Synthesis of Resin A1-10]
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 monomer (a4-0-19) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-11):monomer (a2-1-1):monomer (a3-4-2):monomer (a4-0-19)] is The mixture was mixed at a ratio of 18.5:18.5:5.5:55:2.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain a resin A1-10 having a weight average molecular weight of 8.9×10 ³ with a yield of 60%. This resin A1-10 has the following structural units.

Synthesis Example 13 [Synthesis of Resin A1-11]
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 monomer (a4-0-34) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-11):monomer (a2-1-1):monomer (a3-4-2):monomer (a4-0-34)] is The mixture was mixed at a ratio of 18.5:18.5:5.5:55:2.5, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-11 having a weight average molecular weight of 7.8×10 ³ with a yield of 63%. This resin A1-11 has the following structural units.

Synthesis Example 14 [Synthesis of Resin A1-12]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a3-2-1), a monomer (a3-4-2) and a monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-11):monomer (a3-2-1):monomer (a3-4-2):monomer (a4-0-3)] is The mixture was mixed so as to be 18.5:18.5:10:50:3, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain a resin A1-12 having a weight average molecular weight of 7.6×10 ³ with a yield of 65%. This resin A1-12 has the following structural units.

Synthesis Example 15 [Synthesis of Resin A1-13]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a3-2-1), a monomer (a3-4-2) and a monomer (a4-0-19) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-11):monomer (a3-2-1):monomer (a3-4-2):monomer (a4-0-19)] is The mixture was mixed so as to be 18.5:18.5:10:50:3, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-13 having a weight average molecular weight of 8.9×10 ³ with a yield of 62%. This resin A1-13 has the following structural units.

Synthesis Example 16 [Synthesis of Resin A1-14]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a3-2-1), a monomer (a3-4-2) and a monomer (a4-0-34) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-11):monomer (a3-2-1):monomer (a3-4-2):monomer (a4-0-34)] is The mixture was mixed so as to be 18.5:18.5:10:50:3, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain Resin A1-14 having a weight average molecular weight of 8.0×10 ³ with a yield of 66%. This resin A1-14 has the following structural units.

Synthesis Example 17 [Synthesis of Resin A2-1]
As the monomer, a monomer (a5-1-1) and a monomer (a4-0-12) were used, and the molar ratio (monomer (a5-1-1):monomer (a4-0-12)) was 50:50. The mixture was mixed so as to obtain a solution by adding methyl isobutyl ketone in an amount of 0.6 times the total amount of the monomers. Azobis(2,4-dimethylvaleronitrile) as an initiator was added to this solution in an amount of 3 mol% based on the total amount of the monomers, and the mixture was heated at 70° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered to obtain a resin A2-1 having a weight average molecular weight of 1.5×10 ⁴ with a yield of 88%. .. This resin A2-1 has the following structural units.

Synthesis Example 18 [Synthesis of Resin X1]
As the monomer, a monomer (a1-1-2), a monomer (a3-2-1) and a monomer (a4-0-3) were used, and the molar ratio thereof was [monomer (a1-1-2):monomer (a3-2). -1): Monomer (a4-0-3)] was mixed so as to be 40:20:40, and propylene glycol monomethyl ether acetate in an amount of 1.5 mass times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain a resin X1 having a weight average molecular weight of 7.3×10 ³ with a yield of 65%. This resin X1 has the following structural units.

Synthesis Example 19 [Synthesis of Resin X2]
As the monomer, a monomer (a1-1-1), a monomer (a2-1-x) and a monomer (a4-0-3) were used, and the molar ratio thereof was [monomer (a1-1-1):monomer (a2-1). -X): Monomer (a4-0-3)] was mixed so as to be 30:30:40, and propylene glycol monomethyl ether acetate in an amount of 1.5 mass times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain a resin X2 having a weight average molecular weight of 7.0×10 ³ with a yield of 67%. This resin X2 has the following structural units.

Synthesis Example 20 [Synthesis of Resin X3]
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 monomer (a4-0-3) are used, The molar ratio [monomer (a1-1-3):monomer (a1-2-9):monomer (a2-1-1):monomer (a3-4-2):monomer (a4-0-3)] is The mixture was mixed at 20:20:2:48:10, and propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, 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 obtained resin was repulped in a methanol/water mixed solvent and filtered to obtain a resin X3 having a weight average molecular weight of 7.2×10 ³ with a yield of 64%. This resin X3 has the following structural units.

<Preparation of resist composition>
Each of the components shown below was dissolved in a solvent in an amount by mass shown in Table 1 and filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

＜溶剤＞
プロピレングリコールモノメチルエーテルアセテート ２６５部
プロピレングリコールモノメチルエーテル ２０部
２−ヘプタノン ２０部
γ−ブチロラクトン ３．５部 <Resin>
A1-1 to A1-8, A2-1, X1 to X3: Resin A1-1 to Resin A1-8, Resin A2-1, Resin X1 to Resin X3
<Acid generator>
B1-21: Salt represented by formula (B1-21) B1-22: Salt represented by formula (B1-22) <Compound (D)>
D1: (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Solvent>
Propylene glycol monomethyl ether acetate 265 parts Propylene glycol monomethyl ether 20 parts 2-heptanone 20 parts γ-butyrolactone 3.5 parts

<Residue evaluation>
A 12-inch silicon wafer was coated with a composition for organic antireflection film [ARC-29; manufactured by Nissan Chemical Co., Ltd.] and baked at 205° C. for 60 seconds to give an organic film having a thickness of 78 nm. An antireflection film was formed. Then, the above resist composition was spin-coated on the organic antireflection film so that the composition layer after drying (prebaking) had a thickness of 85 nm. The silicon wafer coated with the resist composition was pre-baked on a direct hot plate at the temperature described in the "PB" column of Table 1 for 60 seconds to form a composition layer on the silicon wafer. On the composition layer formed on the silicon wafer, an ArF excimer laser stepper for immersion exposure [XT: 1900Gi; manufactured by ASML, NA=1.35, Dipole 0.900/0.700 Y-pol. With illumination, a mask for forming a trench pattern (pitch: 120 nm/trench: 40 nm) was used, and the exposure amount was changed stepwise to perform exposure. Ultrapure water was used as the immersion medium. After exposure, post-exposure bake was performed for 60 seconds on the hot plate at the temperature described in the "PEB" column of Table 1. Then, the composition layer after heating was developed by a dynamic dispensing method at 23° C. for 20 seconds using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution to produce a negative resist pattern. ..

In the obtained resist pattern, the exposure amount at which the line width of the trench pattern was 40 nm was defined as the effective sensitivity.

The trench pattern produced at effective sensitivity was observed with a scanning electron microscope. The surface of the substrate that had been dissolved in the developer in the unexposed area was observed, and the case where no residue was observed was rated as O, and the case where a residue was observed was rated as X. The results are shown in Table 2.

<Line edge roughness evaluation (LER)>
A 12-inch silicon wafer was coated with a composition for organic antireflection film [ARC-29; manufactured by Nissan Chemical Co., Ltd.] and baked at 205° C. for 60 seconds to give an organic film having a thickness of 78 nm. An antireflection film was formed. Next, the above resist composition was spin-coated on the above organic antireflection film so that the film thickness of the composition layer after drying (prebaking) was 100 nm. After coating, this silicon wafer was pre-baked on a direct hot plate at the temperature described in the "PB" column of Table 1 for 60 seconds to form a composition layer on the silicon wafer.
ArF excimer laser stepper for immersion exposure [XT: 1900Gi; manufactured by ASML, NA=1.35, Annual σ _out =0.85 σ _in =0.65 XY- is applied to the composition layer formed on the silicon wafer. pol. With illumination, a mask for forming a trench pattern (pitch: 120 nm/trench width: 40 nm) was used, and the exposure amount was changed stepwise for exposure. Ultrapure water was used as the immersion medium.
After exposure, post-exposure bake was performed for 60 seconds on the hot plate at the temperature described in the "PEB" column of Table 1. Then, the composition layer on the silicon wafer is developed by butyl acetate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as a developing solution at 23° C. for 20 seconds by a dynamic dispensing method to form a negative resist pattern. Manufactured.

In the obtained resist pattern, the exposure amount at which the width of the trench pattern was 40 nm was defined as the effective sensitivity.

With respect to the obtained resist pattern, the swing width of the unevenness of the wall surface was observed and measured with a scanning electron microscope. This swing is
A film having a thickness of 3 nm or less was evaluated as having a good LER, and
Those having a thickness of more than 3 nm were evaluated as poor LER and rated as x. The results are shown in Table 2. The numerical value in parentheses indicates the swing width (nm).

From the above results, it can be seen that, according to the resist composition of the present invention, a residue does not occur and a resist pattern can be produced with good line edge roughness (LER).

The resist composition of the present invention is suitable for microfabrication of semiconductors because no residue is generated in the obtained resist pattern and a resist pattern can be produced with good line edge roughness (LER).

Claims (11)

A resin (A1) containing a structural unit represented by formula (a4-0), a structural unit represented by formula (a3-4), and a structural unit having an acid labile group, and an acid generator. A resist composition,
The resist composition, wherein the content of the structural unit represented by the formula (a4-0) is 0.5 mol% or more and 9.5 mol% or less based on the total of all structural units of the resin (A1).

[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

[In formula (a3-4),
R ^a24 represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
L ^a7 represents a single ^{bond, * - O -, * -} O-L a8 -O -, * - O-L a8 -CO-O -, * - O-L a8 -CO-O-L a9 -CO- Represents O- or *-O- ^La8- O-CO- ^La9- O-.
* Represents a bond with the carbonyl group.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms.
R ^a25 represents a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
w1 represents an integer of 0 to 8. When w1 is 2 or more, a plurality of R ^a25 may be the same as or different from each other. ] Resin (A1) containing a structural unit represented by formula (a4-0), a structural unit represented by formula (a1-1), and a structural unit represented by formula (a1-2), and acid generation A resist composition containing an agent,
The resist composition, wherein the content of the structural unit represented by the formula (a4-0) is 0.5 mol% or more and 9.5 mol% or less based on the total of all structural units of the resin (A1).

[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1- CO-O-, k1 represents an integer of 1 to 7, and * represents a bond with -CO-. Representing a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents the integer of 0-14.
n1 represents the integer of 0-10.
n1' represents the integer of 0-3. ] A resist composition containing a resin (A1) containing a structural unit represented by formula (a4-0) and a structural unit having an acid labile group, an acid generator, and a weak acid intramolecular salt represented by formula (D). A thing,
The resist composition, wherein the content of the structural unit represented by the formula (a4-0) is 0.5 mol% or more and 9.5 mol% or less based on the total of all structural units of the resin (A1).

[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a C 1-8 perfluoroalkanediyl group or a C 3-12 perfluorocycloalkanediyl group.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

[In the formula (D),
R ^D1 and R ^D2 are, independently of each other, a monovalent hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, and an acyloxy group having 2 to 7 carbon atoms. Represents an alkoxycarbonyl group having 2 to 7 carbon atoms, a nitro group or a halogen atom.
m′ and n′ each independently represent an integer of 0 to 4, when m′ is 2 or more, a plurality of R ^D1 may be the same or different, and when n′ is 2 or more, A plurality of R ^D2 may be the same or different. ] The resist composition according to claim 1, wherein L ³ is a perfluoroalkanediyl group having 1 to 2 carbon atoms. The resist composition according to claim 1, wherein R ⁶ is a fluorine atom. Wherein the content of the structural unit represented by (a4-0) is the total of all the structural units of the resin (A1), according to claim 1 or less 4.5 mol% to 0.5 mol% 5 The resist composition according to any one of 1. The structural unit having an acid labile group has a structural unit represented by the formula (a1-1) or a structural unit represented by the formula (a1-2), cites claim 3, claim 1 and claim 1. The resist composition according to any one of claims 4 to 6 , which cites claims 4 to 6 and claim 3 .

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or *—O—(CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond with —CO—. Representing a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these.
m1 represents the integer of 0-14.
n1 represents the integer of 0-10.
n1' represents the integer of 0-3. ] Acid generator, a resist composition according to any one of claims 1 to 7, which is a salt represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the methyl group and the monovalent it is, -O - - -CH ₂ contained in the alicyclic hydrocarbon group, - SO ₂ - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ] Claim 1 which further contains the salt which generate|occur|produces the acid whose acidity is weaker than the acid which generate|occur|produces from an acid generator , Claims 4-8 which refer to Claim 1 , Claim 2 and Claim 2. The resist composition according to any one of 4 to 8 . Resist composition has a fluorine atom, and the resist composition according to any one of claims 1-9, further containing a resin (A2) which does not include a structural unit having an acid labile group. (1) A step of applying the resist composition according to any one of claims 1 to 10 onto a substrate,
(2) a step of drying the composition after coating to form a composition layer,
(3) a step of exposing the composition layer,
(4) heating the composition layer after exposure, and (5) developing the composition layer after heating,
A method of manufacturing a resist pattern including: