JP2015168712A - Resin composition and resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition from which a resist pattern with good resolution can be produced.SOLUTION: The resin composition comprises: (X1) a resin that includes a structural unit having a salt structure in a side chain, in which an anionic moiety of the salt structure is bonded to the main chain; and (X2) a resin that includes a structural unit having a salt structure in a side chain, in which a cationic moiety of the salt structure is bonded to the main chain. The resins represented by (X1) and (X2) are preferably resins that generate an acid by an action of an acid or light. The cationic moieties of the salt structures in (X1) and (X2) have a common structure and contain an iodonium ion or a sulfonium ion. The anionic moiety includes a sulfonate ion or a carboxylate ion.

Description

  The present invention relates to a resin composition and a resist composition.

また、特許文献２には、樹脂として、下記式で表される塩に由来する構造単位を含む樹脂（Ｙ２）を含有するレジスト組成物が記載されている。

Patent Document 1 describes a resist composition containing, as a resin, a resin (Y1) containing a structural unit derived from a salt represented by the following formula.

Patent Document 2 describes a resist composition containing, as a resin, a resin (Y2) containing a structural unit derived from a salt represented by the following formula.

JP 2007-197718 A JP 2011-37836 A

  In the resist composition containing the resin (Y1) and the resist composition containing the resin (Y2), the resolution of the resist pattern may not always be sufficient.

［式（Ｉ）中、
Ｌ^１は、置換基を有していてもよい炭素数１〜３６の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子はフッ素原子に置き換わっていてもよい。
Ｒ^１、Ｒ^２及Ｒ^３は、それぞれ独立に、置換基を有していてもよい炭素数１〜１８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−で置き換わっていてもよい。Ｒ^１とＲ^２とは、互いに結合して環を形成してもよく、該環に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−、−ＣＯ−又は＝Ｎ−に置き換わっていてもよい。
Ａ^＋は、ヨードニウムイオン又はスルホニウムイオンを表す。
＊は、主鎖との結合手を表す。］］
［１４］（Ｘ２）における塩構造が、式（ＩＩ）で表される構造である［１］〜［１３］に記載の樹脂組成物。

［式（ＩＩ）中、
Ｒ^４及Ｒ^５は、それぞれ独立に、置換基を有していてもよい炭素数１〜１８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−で置き換わっていてもよい。Ｒ^４とＲ^５とは、互いに結合して環を形成してもよく、該環に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−、−ＣＯ−又は＝Ｎ−に置き換わっていてもよい。
Ｒ^６は、置換基を有していてもよい炭素数１〜３６の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−、−ＣＯ−又は−ＮＲ^１１−で置き換わっていてもよく、Ｒ^１１は炭素数１〜６のアルキル基を表す。
Ｌ^２は、炭素数１〜１８の２価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−で置き換わっていてもよい。
Ｄ^＋は、ヨードニウムイオン又はスルホニウムイオンを表す。
＊は、主鎖との結合手を表す。］
［１５］［１］〜［１４］に記載の樹脂組成物と溶剤とを含むレジスト組成物。
［１６］［１］〜［１５］に記載の樹脂組成物またはレジスト組成物と、酸発生剤とを含むレジスト組成物。
［１７］［１］〜［１６］に記載の樹脂組成物またはレジスト組成物と、塩基性化合物とを含むレジスト組成物。 The present invention includes the following inventions.
[1] A resin composition comprising the following (X1) and (X2).
(X1) a resin containing a structural unit having a salt structure in the side chain, wherein the anion portion of the salt structure is bonded to the main chain (X2) a resin containing a structural unit having a salt structure in the side chain The resin composition according to [1], wherein the resin [2] in which the cationic site of the salt structure is bonded to the main chain is a resin that generates an acid by the action of an acid or light.
[3] The resin composition according to [1] or [2], wherein the cation moiety having a salt structure in (X1) and the cation moiety having a salt structure in (X2) have a common structure.
[4] The resin composition according to [3], wherein the common structure of the cation moiety of the salt structure in (X1) and the cation moiety of the salt structure in (X2) is a structure containing a cyclic hydrocarbon group.
[5] The resin composition according to any one of [1] to [4], wherein the cation moiety is a moiety containing an iodonium ion or a sulfonium ion.
[6] The resin composition according to [1] to [5], wherein the anion moiety is a moiety containing a sulfonate ion or a carboxylate ion.
[7] The resin composition according to any one of [1] to [6], wherein the salt structure is bonded to the main chain via a linking group containing at least one carbonyl group.
[8] The content ratio ((X1) :( X2)) between (X1) and (X2) is 20: 1 to 1:20 on a mass basis, according to any one of [1] to [7] Resin composition.
[9] The resin composition according to any one of [1] to [8], wherein the structural unit having a salt structure in the side chain is 0.1 to 50 mol% with respect to all the structural units of the resin.
[10] The resin composition according to any one of [1] to [9], wherein the salt structure in (X1) is 0.1 to 50 mol% with respect to all structural units of the resin of (X1).
[11] The resin composition according to any one of [1] to [10], wherein the salt structure in (X2) is 0.1 to 50 mol% with respect to all structural units of the resin of (X2).
[12] The resin composition according to [1] to [11], wherein at least one of the resins (X1) and (X2) includes a structural unit having an acid labile group.
[13] The resin composition according to any one of [1] to [12], wherein the salt structure in (X1) is a structure represented by the formula (I).

[In the formula (I),
L ¹ represents an optionally substituted divalent saturated hydrocarbon group having 1 to 36 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group is —O— or —SO _2. -Or -CO- may be substituted, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted by a fluorine atom.
R ¹ , R ² and R ³ each independently represent a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and —CH ₂ — contained in the hydrocarbon group is —O -Or -CO- may be substituted. R ¹ and R ² may combine with each other to form a ring, and —CH ₂ — contained in the ring is replaced by —O—, —SO ₂ —, —CO— or ═N—. May be.
A ⁺ represents an iodonium ion or a sulfonium ion.
* Represents a bond with the main chain. ]]
[14] The resin composition according to [1] to [13], wherein the salt structure in (X2) is a structure represented by the formula (II).

[In the formula (II),
R ⁴ and R ⁵ each independently represents a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and —CH ₂ — contained in the hydrocarbon group is —O— or — It may be replaced by CO-. R ⁴ and R ⁵ may combine with each other to form a ring, and —CH ₂ — contained in the ring is replaced with —O—, —SO ₂ —, —CO— or ═N—. May be.
R ⁶ represents a C1-36 saturated hydrocarbon group which may have a substituent, and —CH ₂ — contained in the saturated hydrocarbon group is —O—, —SO ₂ —, — CO— or —NR ¹¹ — may be substituted, and R ¹¹ represents an alkyl group having 1 to 6 carbon atoms.
L ² represents a divalent hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the hydrocarbon group may be replaced by —O— or —CO—.
D ⁺ represents an iodonium ion or a sulfonium ion.
* Represents a bond with the main chain. ]
[15] A resist composition comprising the resin composition according to [1] to [14] and a solvent.
[16] A resist composition comprising the resin composition or resist composition according to [1] to [15] and an acid generator.
[17] A resist composition comprising the resin composition or resist composition according to [1] to [16] and a basic compound.

  The resist composition containing the resin composition of the present invention can produce a resist pattern with good resolution.

In the present specification, "(meth) acrylic monomer" means at least one monomer having a "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " structure of To do. Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

<Resin composition>
The resin composition of the present invention (hereinafter sometimes referred to as “resin composition (A)”) includes a resin (X1) and a resin (X2).

（式中、Ｒ^１１１は、水素原子、メチル基又は−ＣＯ−Ｏ−Ｒ^１１２を表し、Ｒ^１１２は炭素数１〜６のアルキル基を表す。
＊は、塩構造との結合手を表す。）
Ｒ^１１２で表される炭素数１〜６のアルキル基としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、ペンチル基、ネオペンチル基、ヘキシル基が挙げられ、好ましくはｔｅｒｔ−ブチル基である。 <Resin (X1)>
First, the resin (X1) will be described.
Resin (X1) is a structural unit having a salt structure in the side chain, and includes a structural unit in which the anion portion of the salt structure is bonded to the main chain (hereinafter sometimes referred to as structural unit (X1)). .
The salt structure means a structure having a cation moiety and an anion moiety.
The main chain in the resin (X1) is represented by the following structure.

(Wherein R ¹¹¹ represents a hydrogen atom, a methyl group, or —CO—O—R ¹¹² , and R ¹¹² represents an alkyl group having 1 to 6 carbon atoms.
* Represents a bond with a salt structure. )
Examples of the alkyl group having 1 to 6 carbon atoms represented by R ¹¹² include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, and a hexyl group. And preferably a tert-butyl group.

The anion site is not particularly limited, and is preferably a monovalent anion site, more preferably an anion site containing a sulfonate ion and an anion site containing a carboxylate ion.
As an anion site | part, the anion site | part containing a hydrocarbon group is mentioned. Carbon number of this hydrocarbon group is 1-36 normally, Preferably it is 1-30, More preferably, it is 1-24. The —CH ₂ — group contained in the hydrocarbon group may be replaced by —O—, —CO ₂ —, —SO ₂ — or ═N—, and the hydrogen atom contained in the hydrocarbon group is A halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, or an acylamino group having 1 to 8 carbon atoms may be substituted.

The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.
Examples of the saturated hydrocarbon group include an alkyl group, a monocyclic or polycyclic alicyclic hydrocarbon group, and the like.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, and preferably 1 to 12 carbon atoms. It is an alkyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Specific examples include a cycloalkyl group having 3 to 18 carbon atoms such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group; an adamantyl group and the like, preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms. It is.
Examples of the unsaturated hydrocarbon group include an alkenyl group, an alkynyl group, an aromatic hydrocarbon group, and the like, and a combination of two or more of these groups may be used.
Examples of the alkenyl group include a vinyl group, 1-propenyl group, 2-propenyl group, 1-methylvinyl group, 2-methyl-1-propenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1- C2-C8 alkynyl groups, such as a pentenyl group and 1-hexenyl group, are mentioned.
Examples of the alkynyl group include alkynyl groups having 2 to 8 carbon atoms such as ethynyl group, propargyl group, 2-butynyl group, 3-butynyl group, 1-pentynyl group and 1-hexynyl group.
Examples of the aromatic hydrocarbon group include monocyclic and polycyclic structures, and ═CH— in the aromatic hydrocarbon group may be replaced by ═N—. Specifically, phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl group, phenanthryl Group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, pyridyl group, imidazolium group, indole group and the like.
As a halogen atom, a fluorine atom, a chlorine atom, and a bromine atom are mentioned, Preferably it is a fluorine atom.

  The anion moiety is preferably a moiety having at least one selected from a fluorine atom, a carbonyl group, an ester bond and an ether bond, and more preferably a moiety having a fluorine atom or a carbonyl group.

The cation moiety is not particularly limited, and is preferably a monovalent cation moiety, more preferably a cation moiety containing an iodonium ion and a cation moiety containing a sulfonium ion.
Examples of the cation moiety include a cation moiety containing a hydrocarbon group. Carbon number of this hydrocarbon group is 1-18 normally, Preferably it is 1-15, More preferably, it is 1-12.
Examples of the hydrocarbon group include those similar to the hydrocarbon group at the anion site, and are aromatic hydrocarbon groups.

The combination of an anion site and a cation site can be arbitrarily combined. The combination of an anion site and a cation site is
A combination of an anionic moiety containing a sulfonate ion and a cationic moiety containing an iodonium ion,
A combination of an anionic moiety containing a sulfonate ion and a cationic moiety containing a sulfonium ion,
A combination of an anion moiety containing a carboxylate ion and a cation moiety containing an iodonium ion,
And a combination of an anionic moiety containing a carboxylate ion and a cationic moiety containing a sulfonium ion,
A combination of an anion moiety containing a sulfonate ion and a cation moiety containing a sulfonium ion is more preferred.

The structural unit (X1) may be a monovalent salt structure or a divalent salt structure, and the valence is not limited. The structural unit (X1) is preferably a monovalent salt structure.
The structural unit (X1) preferably has a structure that generates an acid by the action of light or an acid, and more preferably has a structure that generates an acid by the action of light.

［式（Ｉ）中、
Ｌ^１は、置換基を有していてもよい炭素数１〜３６の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子はフッ素原子に置き換わっていてもよい。
Ｒ^１、Ｒ^２及Ｒ^３は、それぞれ独立に、置換基を有していてもよい炭素数１〜１８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−で置き換わっていてもよい。Ｒ^１とＲ^２とは、互いに結合して環を形成してもよく、該環に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−、−ＣＯ−又は＝Ｎ−に置き換わっていてもよい。
Ａ^＋は、ヨードニウムイオン又はスルホニウムイオンを表す。
＊は、主鎖との結合手を表す。］ The structural unit (X1) is preferably a structure represented by the formula (I) (hereinafter sometimes referred to as the structural unit (I)).

[In the formula (I),
L ¹ represents an optionally substituted divalent saturated hydrocarbon group having 1 to 36 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group is —O— or —SO _2. -Or -CO- may be substituted, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted by a fluorine atom.
R ¹ , R ² and R ³ each independently represent a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and —CH ₂ — contained in the hydrocarbon group is —O -Or -CO- may be substituted. R ¹ and R ² may combine with each other to form a ring, and —CH ₂ — contained in the ring is replaced by —O—, —SO ₂ —, —CO— or ═N—. May be.
A ⁺ represents an iodonium ion or a sulfonium ion.
* Represents a bond with the main chain. ]

Examples of the divalent saturated hydrocarbon group having 1 to 36 carbon atoms include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and these A combination of two or more of the groups may be used.
Examples of the hydrocarbon group having 1 to 18 carbon atoms include a linear or branched alkenyl group, a monocyclic or polycyclic alicyclic hydrocarbon group, and an aromatic hydrocarbon group, and an aromatic hydrocarbon group. It is preferable to contain. Examples of the aromatic hydrogen group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl. Group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, pyridyl group, imidazolium group, indole group and the like.
Examples of the substituent that the hydrocarbon group having 1 to 18 carbon atoms may have include a hydroxy group, a halogen atom, a cyano group, a nitro group, a carboxy group, an alkoxy group having 1 to 8 carbon atoms, an aryloxy group, and carbon. An acyl group having 1 to 8 carbon atoms, an acyloxy group having 2 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 9 carbon atoms, an alkoxycarbonyloxy group having 2 to 9 carbon atoms, an amino group, an acylamino group having 1 to 8 carbon atoms, Examples thereof include an alkoxycarbonylamino group having 2 to 9 carbon atoms and an aryloxycarbonyl group.

It is preferable that at least one —CH ₂ — contained in the saturated hydrocarbon group having 1 to 36 carbon atoms represented by L ¹ is replaced with —CO—.
At least one hydrogen atom contained in the saturated hydrocarbon group having 1 to 36 carbon atoms represented by L ¹ is preferably replaced with a fluorine atom.
R ¹ , R ² and R ³ are preferably all the same group, and R ¹ , R ² and R ³ are preferably phenyl groups.
A ⁺ is preferably a sulfonium ion.

［式（Ｉａ）中、Ｑ^１及びＱ^２は、それぞれ独立して、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
ｎ＝１〜３の整数を表す。
Ｘ^１は、単結合又は置換基を有していてもよい炭素数１〜１２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
Ｗ^１は、置換基を有していてもよい炭素数３〜１８の２価の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−に置き換わっていてもよい。
Ｘ^２は、炭素数１〜８のアルカンジイル基を表し、該アルカンジイル基に含まれる−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｙ^１は、単結合、−Ｏ−、＊−ＣＯ−Ｏ−、＊−Ａｒ−Ｏ−、＊−Ａｒ−ＣＯ−Ｏ−、＊−ＣＯ−Ｏ−Ａｒ−Ｏ−又は＊−ＣＯ−Ｏ−Ａｒ−ＣＯ−Ｏ−を表す。
Ａｒは、フェニレン基を表す。
＊は、樹脂鎖との結合手を表す］ <Anion site>
The anion site in the structural unit (I) is preferably a structure represented by the formula (Ia) (hereinafter sometimes referred to as the structural unit (Ia)).

[In Formula (Ia), Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
n represents an integer of 1 to 3.
X ¹ represents a C 1-12 divalent saturated hydrocarbon group which may have a single bond or a substituent, and —CH ₂ — contained in the saturated hydrocarbon group is —O— or -CO- may be substituted.
W ¹ represents a C 3-18 divalent alicyclic hydrocarbon group which may have a substituent, and —CH ₂ — contained in the alicyclic hydrocarbon group is —O—. , —SO ₂ — or —CO— may be substituted.
X ² represents an alkanediyl group having 1 to 8 carbon atoms, and may be replaced by —O— or —CO— contained in the alkanediyl group.
Y ¹ is a single bond, —O—, * —CO—O—, * —Ar—O—, * —Ar—CO—O—, * —CO—O—Ar—O— or * —CO—O. -Ar-CO-O- is represented.
Ar represents a phenylene group.
* Represents a bond to the resin chain]

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 perfluoro group. A hexyl group etc. are mentioned.
Q ¹ and Q ² are preferably each independently a fluorine atom or a trifluoromethyl group, and more preferably a fluorine atom.
n represents an integer of 1 to 10.

Examples of the divalent saturated hydrocarbon group for X ¹ include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and among these groups, Two or more types may be combined.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Straight-chain alkanediyl groups such as dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group;
Butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4- Branched alkanediyl groups such as diyl, ethane-1,1-diyl, propane-1,1-diyl and propane-2,2-diyl;
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 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, adamantane-2,6-diyl group, etc. Groups and the like.

Examples of the substituent that the divalent saturated hydrocarbon group represented by X ¹ may have include a hydroxy group and a fluorine atom.

式（Ｘ１−１）中、
Ｌ^1１は、＊−ＣＯ−Ｏ−又は＊−Ｏ−ＣＯ−を表す。＊は、Ｘ^４との結合手を表す。
Ｘ^４は、単結合又はフッ素原子を有していてもよい炭素数１〜１３のアルカンジイル基を表す。
Ｘ^５は、単結合又は炭素数１〜１３のアルカンジイル基を表す。
ただし、Ｘ^４及びＸ^５の合計炭素数は、１３以下である。
式（Ｘ１−２）中、
Ｘ^６は、単結合又はフッ素原子を有していてもよい炭素数１〜１４のアルカンジイル基を表す。
Ｘ^７は、単結合又は炭素数１〜１３のアルカンジイル基を表す。
ただし、Ｘ^６及びＸ^７の合計炭素数は、１以上１４以下である。
式（Ｘ１−３）中、
Ｌ¹²は、＊−ＣＯ−Ｏ−又は＊−Ｏ−ＣＯ−を表す。＊は、Ｘ^９との結合手を表す。
Ｘ^８は、単結合又はフッ素原子を有していてもよい炭素数１〜１２のアルカンジイル基を表す。
Ｘ^９及びＸ^１０は、それぞれ独立に、単結合又は炭素数１〜１２のアルカンジイル基を表す。
ただし、Ｘ^８、Ｘ^９及びＸ^１０の合計炭素数は、１２以下である。
式（Ｘ１−４）中、
Ｌ¹³は、＊−ＣＯ−Ｏ−又は＊−Ｏ−ＣＯ−を表す。＊は、Ｘ¹¹との結合手を表す。
Ｘ¹¹は、単結合又はフッ素原子を有していてもよい炭素数１〜１２のアルカンジイル基を表す。
Ｘ¹²及びＸ¹³は、それぞれ独立に、単結合又は炭素数１〜１２のアルカンジイル基を表す。
ただし、Ｘ¹¹、Ｘ¹²及びＸ¹³の合計炭素数は、１２以下である。
式（Ｘ１−５）中、
Ｌ¹⁴及びＬ¹⁵は、それぞれ独立に、＊−ＣＯ−Ｏ−又は＊−Ｏ−ＣＯ−を表す。Ｌ^４における＊は、Ｘ¹⁴との結合手を表し、Ｌ^５における＊は、Ｘ¹⁵との結合手を表す。
Ｘ¹⁴は、単結合又はフッ素原子を有していてもよい炭素数１〜１２のアルカンジイル基を表す。
Ｘ¹⁵は、炭素数１〜１２のアルカンジイル基を表す。
Ｘ¹⁶は、単結合又は炭素数１〜１１のアルカンジイル基を表す。
ただし、Ｘ¹⁴、Ｘ¹⁵及びＸ¹⁶の合計炭素数は、１１以下である。 Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by X ¹ is replaced by —O— or —CO— include those represented by formula (X1-1) to formula (X1-5). And the group represented. In the following formula, * represents a bond with -O-.

In formula (X1-1),
L ¹¹ represents * —CO—O— or * —O—CO—. * Represents a bond to ^{X 4.}
X ⁴ represents a C 1-13 alkanediyl group which may have a single bond or a fluorine atom.
X ⁵ represents a single bond or an alkanediyl group having 1 to 13 carbon atoms.
However, the total number of carbon atoms of ^{X 4} and ^{X 5} is 13 or less.
In formula (X1-2),
X ⁶ represents a C 1-14 alkanediyl group which may have a single bond or a fluorine atom.
X ⁷ represents a single bond or an alkanediyl group having 1 to 13 carbon atoms.
However, the total carbon number of X ⁶ and X ⁷ is 1 or more and 14 or less.
In formula (X1-3),
L ¹² represents * —CO—O— or * —O—CO—. * Represents a bond to ^{X 9.}
X ⁸ represents a single bond or a fluorine atom having 1 to 12 carbon atoms which may have alkanediyl group.
X ⁹ and X ¹⁰ each independently represent a single bond or an alkanediyl group having 1 to 12 carbon atoms.
However, the total carbon number of X ⁸ , X ⁹ and X ¹⁰ is 12 or less.
In formula (X1-4),
L ¹³ represents * —CO—O— or * —O—CO—. * Represents a bond to X ^11.
X ¹¹ represents a single bond or a fluorine atom having 1 to 12 carbon atoms which may have alkanediyl group.
X ¹² and X ¹³ each independently represent a single bond or an alkanediyl group having 1 to 12 carbon atoms.
However, the total carbon number of X ¹¹ , X ¹² and X ¹³ is 12 or less.
In formula (X1-5),
L ¹⁴ and L ¹⁵ each independently represent * —CO—O— or * —O—CO—. * In L ⁴ represents a bond with X ^14, and * in L ⁵ represents a bond with X ¹⁵ .
X ¹⁴ represents a C 1-12 alkanediyl group which may have a single bond or a fluorine atom.
X ¹⁵ represents an alkanediyl group having 1 to 12 carbon atoms.
X ¹⁶ represents a single bond or an alkanediyl group having 1 to 11 carbon atoms.
However, the total carbon number of X ¹⁴ , X ¹⁵ and X ¹⁶ is 11 or less.

  Examples of alkanediyl groups include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane- 1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl Group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, butane-1,3-diyl group, 2-methyl Propane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, ethane-1,1-diyl group, Propane-1, - such diyl group and propane-2,2-diyl group.

L ¹¹ is preferably * —CO—O—.
X ⁴ is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms, more preferably a single bond or a methylene group.
X ⁵ is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms, more preferably a single bond or a methylene group.

X ⁶ is preferably an alkanediyl group having 1 to 6 carbon atoms which may have a fluorine atom, more preferably a single bond, a methylene group or a difluoromethylene group.
X ⁷ is preferably an alkanediyl group having 1 to 6 carbon atoms, more preferably a single bond or a methylene group.

X ⁸ is preferably an alkanediyl group having 1 to 6 carbon atoms which may have a fluorine atom, more preferably a single bond, a methylene group or a difluoromethylene group.
X ⁹ and X ¹⁰ are preferably each independently a single bond or an alkanediyl group having 1 to 6 carbon atoms.
L ¹² is preferably * —CO—O—.

L ¹³ is preferably * —CO—O—.
X ¹¹ is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms, more preferably a single bond or a methylene group.
X ¹² and X ¹³ are preferably each independently a single bond or an alkanediyl group having 1 to 6 carbon atoms.

L ¹⁴ is preferably * —CO—O—.
L ¹⁵ is preferably * —CO—O—.
X ¹⁴ is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms, more preferably a single bond or a methylene group.
X ¹⁵ is preferably an alkanediyl group having 1 to 6 carbon atoms, more preferably a methylene group.
X ¹⁶ is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms, more preferably a single bond or a methylene group.

Examples of the group represented by the formula (X1-1) include the following divalent groups.

Examples of the group represented by the formula (X1-2) include the following divalent groups.

Examples of the group represented by the formula (X1-3) include the following divalent groups.

Examples of the group represented by the formula (X1-4) include the following divalent groups.

Examples of the group represented by the formula (X1-5) include the following divalent groups.

X ¹ is preferably a group represented by the formula (X1-1).

Examples of the divalent saturated hydrocarbon group for X ¹ include the following divalent groups.

Examples of the divalent alicyclic hydrocarbon group for W ¹ include groups represented by formulas (Y1 ′) to (Y11 ′). The groups in which —CH ₂ — contained in the alicyclic hydrocarbon group is replaced by —O—, —SO ₂ — or —CO— are represented by formulas (Y12 ′) to (Y26 ′). Group to be used.

The divalent alicyclic hydrocarbon group for W ¹ is preferably a group represented by any one of the formulas (Y1 ′) to (Y19 ′), more preferably the formula (Y4 ′) and the formula (Y9 ′), Formula (Y10 ′), Formula (Y11 ′), Formula (Y14 ′), Formula (Y15 ′), or Group represented by Formula (Y19 ′), and more preferably Formula (Y4 ′), Formula (Y9 ′), a group represented by Formula (Y10 ′) or Formula (Y11 ′).

Examples of the substituent that the divalent alicyclic hydrocarbon group represented by W ¹ may have include a halogen atom, a hydroxy group, and an alkyl group having 1 to 12 carbon atoms that may have a hydroxy group. , An alicyclic hydrocarbon group having 3 to 16 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, and 2 to 4 carbon atoms An acyl group, a glycidyloxy group or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms and an alicyclic hydrocarbon group having 3 to 16 carbon atoms) Or an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 represents an integer of 0 to 4), and the like is preferable.
The divalent alicyclic hydrocarbon group of W ¹ is preferably unsubstituted.

Examples of the alkyl group which may have a hydroxy group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the aralkyl group include 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.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl group, and the like.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

W ¹ is preferably a divalent group represented by the following formula.

Examples of the alkanediyl group having 1 to 8 carbon atoms of X ² 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, and a pentane- Linear alkanediyl groups such as 1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group;
Butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4- And branched alkanediyl groups such as a diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, and a propane-2,2-diyl group.

As the alkanediyl group in which —CH ₂ — contained in the alkanediyl group having 1 to 8 carbon atoms represented by X ² is replaced by —O— or —CO—, * —O—CO— (CH ₂ ) _{h1 -, * - O- (CH} 2) h2 -, * - CO-O- (CH 2) h3 - , and the like. Here, h1 and h3 represent an integer of 0 to 6, h2 represents an integer of 0 to 7, and * represents a bond with W ¹ .

X ² is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms, and more preferably a single bond or a methylene group.

Y ¹ is a single bond, —O—, * —CO—O—, * —Ar—O—, * —Ar—CO—O—, * —CO—O—Ar—O— or * —CO—O. -Ar-CO-O- is represented.
Ar represents a phenylene group.
* Represents a bond with a resin chain. )

Examples of the anion moiety in the structural unit (I) include anion moieties represented by formulas (Ia-1) to (Ia-8). The anion moiety in the structural unit (I) is preferably an anion moiety represented by the formula (Ia-1), the formula (Ia-2) or the formula (Ia-8).
* Represents a bond with a resin chain.

<Cation site>
Examples of the aliphatic hydrocarbon group having 1 to 10 carbon atoms of R ¹ , R ² and R ³ 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. Group, pentyl group, hexyl group, octyl group, decyl group and 2-ethylhexyl group.
Examples of the substituent that the aliphatic hydrocarbon group may have include an alicyclic hydrocarbon group having 3 to 12 carbon atoms, a hydroxy group, an alkoxy group having 1 to 8 carbon atoms, and an acyl having 1 to 8 carbon atoms. Group, an alkoxycarbonyl group having 2 to 9 carbon atoms, an acyloxy group having 2 to 8 carbon atoms, and the like.

The alicyclic hydrocarbon group having 4 to 36 carbon atoms may be monocyclic or polycyclic. Examples of the monocyclic aliphatic hydrocarbon group include a cyclobutyl 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 and a norbornyl group.
Examples of the substituent that the alicyclic hydrocarbon group may have include an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a hydroxy group, an alkoxy group having 1 to 8 carbon atoms, and an acyl having 1 to 8 carbon atoms. Group, an alkoxycarbonyl group having 2 to 9 carbon atoms, an acyloxy group having 2 to 8 carbon atoms, and the like.

Examples of the aromatic hydrocarbon group having 6 to 36 carbon atoms include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group. Groups, mesityl groups, biphenyl groups, phenanthryl groups, 2,6-diethylphenyl groups, and aryl groups such as 2-methyl-6-ethylphenyl.
Examples of the substituent that the aromatic hydrocarbon group may have include a hydroxy group, a halogen atom, a cyano group, a nitro group, a carboxy group, an alkoxy group having 1 to 8 carbon atoms, an aryloxy group, and 1 to 1 carbon atoms. 8 acyl group, C2-C8 acyloxy group, C2-C9 alkoxycarbonyl group, C2-C9 alkoxycarbonyloxy group, amino group, C1-C8 acylamino group, C2 -9 alkoxycarbonylamino group, aryloxycarbonyl group, etc. are mentioned, A hydroxy group, a halogen atom, a C1-C8 alkoxy group, and a C1-C8 acyl group are preferable.

Examples of the acyl group include formyl group, acetyl group, propionyl group and butyryl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group and octyloxy group.

Examples of the ring formed by combining ^{two of} R ¹ , R ² and R ³ include a heterocyclic ring containing at least one sulfur atom. Examples thereof include a ring represented by the following formula.

R ¹ and R ² are preferably an alicyclic hydrocarbon group or an aromatic hydrocarbon group, and more preferably an aromatic hydrocarbon group.
R ³ is preferably a divalent group containing an aromatic hydrocarbon group, more preferably a divalent aromatic hydrocarbon group.

Examples of the cation moiety in the structure represented by formula (I) include cation moieties represented by formula (Ib-1) to formula (Ib-24). The cation moiety in the structure represented by formula (I) is preferably a cation moiety represented by formula (Ib-5), formula (Ib-10) or formula (Ib-17).

  As the structural unit (I), an anion moiety represented by the formula (Ia-1) to the formula (Ia-8) and a cation moiety represented by the formula (Ib-1) to the formula (Ib-24) are arbitrarily selected. The structural units shown in Table 1 and Table 2 are mentioned, for example. The structural unit (I) is preferably the formula (I-5), formula (I-10), formula (I-29), formula (I-34), formula (I-41), formula (I-53). , A structural unit represented by formula (I-58) or formula (I-65).

  The content of the structural unit (X1) is usually from 0.1 to 50 mol%, preferably from 1 to 30 mol%, more preferably from 2 to 20 mol, based on all structural units of the resin (X1). %. Resin (X1) may contain 2 or more types of structural units (X1).

  The resin (X1) may contain a structural unit other than the structural unit (X1). Examples of the other structural unit include a structural unit having an acid labile group (hereinafter sometimes referred to as structural unit (a1)). The acid labile group means a group having a leaving group, and the leaving group is removed by contact with an acid to convert a structural unit into a hydrophilic group (for example, a hydroxy group or a carboxy group).

<Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”). As the acid labile group, a group represented by the formula (1) and a group represented by the formula (2) are preferable.

［式（１）中、Ｒ^a1〜Ｒ^a3は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組合わせた基を表すか、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する。
ｎａは、０又は１を表す。
＊は結合手を表す。］

［式（２）中、Ｒ^a1’及びＲ^a2’は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^a3’は、炭素数１〜２０の炭化水素基を表すか、Ｒ^a2’及びＲ^a3’は互いに結合して炭素数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。
Ｘは、酸素原子又は硫黄原子を表す。
＊は結合手を表す。］ The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, more preferably a (meth) acrylic monomer having an acid labile group.

[In Formula (1), R ^<a1 > -R < ^a3 > respectively independently represents a C1-C8 alkyl group, a C3-C20 alicyclic hydrocarbon group, or the group which combined these, R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms.
na represents 0 or 1.
* Represents a bond. ]

[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. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group. May be replaced by -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わせた基としては、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基等が挙げられる。
ｎａは、好ましくは０である。 ^Examples of the alkyl group represented by 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 for R ^{a1 to} R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups (* represents a bond). 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.
na is preferably 0.

Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group include the following groups. The divalent hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

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

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 alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the divalent hydrocarbon group formed by combining R ^{a2 ′} and R ^{a3 ′} include groups in which one hydrogen atom has been removed from the hydrocarbon groups of R ^{a1 ′ to} R ^{a3 ′} .
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.

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

  Among the (meth) acrylic monomers having an acid labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. If the resin (X1) having a structural unit derived from the monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

  As a structural unit derived from a (meth) acrylic monomer having a group represented by the formula (1), a structural unit represented by the formula (a1-0) is preferably represented by the formula (a1-1). The structural unit represented by a structural unit or a formula (a1-2) is mentioned. These may be used alone or in combination of two or more. In this specification, the structural unit represented by formula (a1-0), the structural unit represented by formula (a1-1), and the structural unit represented by formula (a1-2) are each represented by structural unit (a1). -0), structural unit (a1-1) and structural unit (a1-2), a monomer for deriving structural unit (a1-0), a monomer for deriving structural unit (a1-1), and a structural unit (a1- The monomer that induces 2) may be referred to as monomer (a1-0), monomer (a1-1), and monomer (a1-2), respectively.

［式（ａ１−０）中、
Ｌ^a01は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_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、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a02、Ｒ^a03及びＲ^a04は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合わせた基を表す。］

[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 to 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 obtained by combining these. ]

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_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、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合わ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 to —CO—. Represents 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 an integer of 0 to 10.
n1 ′ represents an integer of 0 to 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, more preferably 1.
Examples of the alkyl group of R ^a02 , R ^a03, and R ^a04 , the alicyclic hydrocarbon group, and the group obtained by combining these include the same groups as those described for R ^{a1 to} R ^a3 in formula (1).
The alkyl group for R ^a02 , R ^a03 and R ^a04 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group ^{represented by} R ^a02 , R ^a03 and R ^a04 preferably has 8 or less carbon atoms, more preferably 6 or less.
The group combining the alkyl group and the alicyclic hydrocarbon group preferably has a total carbon number of 18 or less, combining the alkyl group and the alicyclic hydrocarbon group. 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, 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 for R ^a6 and R ^a7 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, Examples include n-heptyl group, 2-ethylhexyl group, n-octyl group and the like.
The alicyclic hydrocarbon group for R ^a6 and R ^a7 may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, Examples thereof include cycloalkyl groups such as a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cycloheptyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, and norbornyl. Group, methylnorbornyl group, isobornyl group and the like.
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 examples thereof include a benzyl group and a phenethyl group.
The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group of R ^a6 and R ^a7 preferably has 8 or less carbon atoms, more preferably 6 or less.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As the monomer (a1-0), a monomer represented by any one of the formulas (a1-0-1) to (a1-1-12) is preferable, and the formula (a1-0-1) to the formula (a1- The monomer represented by any one of 1-10) is more preferable.

In the above structural unit, a structural unit in which a methyl group corresponding to R ^a01 is replaced with a hydrogen atom can also be given as a specific example of the structural unit (a1-0).

As a monomer (a1-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned. Among these, a monomer represented by any one of formula (a1-1-1) to formula (a1-1-8) is preferable, and any one of formula (a1-1-1) to formula (a1-1-4) is preferable. The monomer represented by is more preferable.

As the monomer (a1-2), 1-methylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclopentan-1-yl (meth) acrylate, 1-methylcyclohexane-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, 1-ethylcycloheptan-1-yl (meth) acrylate, 1-ethylcyclooctane-1-yl (meth) acrylate, 1-isopropylcyclopentan-1-yl (Meth) acrylate, 1-isopropylcyclohexane-1-yl (meth) acrylate, etc. are mentioned. A monomer represented by any one of the formulas (a1-2-1) to (a1-2-12) is preferable, and the formula (a1-2-3), the formula (a1-2-4), the formula (a1- The monomer represented by 2-9) or formula (a1-2-10) is more preferred, and the monomer represented by formula (a1-2-3) or formula (a1-2-9) is more preferred.

  When the resin (x1) includes the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is the total structure of the resin (X1). It is 5-60 mol% normally with respect to a unit, Preferably it is 10-50 mol%, More preferably, it is 15-40 mol%.

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、又はこれらを組み合わ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、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組合わせることにより形成される基を表すか、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。 Furthermore, examples of the structural unit (a1) having the group (1) include 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). Moreover, the monomer which derives the structural unit (a1-3) may be referred to as a monomer (a1-3).

In formula (a1-3),
R ^a9 represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxy group, 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 a combination thereof, the aliphatic hydrocarbon group and the 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 by -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, R ^a10 and R ^a11 are bonded to 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, -COOR ^a13 includes a group 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 of R ^a9 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group and a 2-hydroxyethyl group.
^Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms represented by R ^a13 include a methyl group, an ethyl group, and a propyl group.
^Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^a13 include a cyclopentyl group, a cyclopropyl group, an adamantyl group, an adamantylmethyl group, a 1-adamantyl-1-methylethyl group, and 2-oxo-oxolane-3- Yl group and 2-oxo-oxolan-4-yl group.
^Examples of the alkyl group represented by R ^{a10 to} R ^a12 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, Examples include n-heptyl group, 2-ethylhexyl group, n-octyl group and the like.
The alicyclic hydrocarbon group for R ^{a10 to} R ^a12 may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, Examples thereof include cycloalkyl groups such as a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cycloheptyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, norbornyl group, Examples thereof include a methylnorbornyl group and an isobornyl group.
-C (R ^a10 ) (R ^a11 ) (R ^a12 ) 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, Groups are preferred.

  Specific examples of the monomer (a1-3) include 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 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-methyl 5-norbornene-2-carboxylate Chill, and the like.

  Since the resin (X1) containing the structural unit (a1-3) includes a sterically bulky structural unit, the resist composition of the present invention containing such a resin (X1) is more expensive. A resist pattern can be obtained with resolution. Further, since a rigid norbornane ring is introduced into the main chain, the resulting resist pattern tends to be excellent in dry etching resistance.

  When the resin (X1) contains the structural unit (a1-3), the content thereof is preferably 5 to 50 mol%, more preferably 10 to 40 mol%, based on all the structural units of the resin (X1). 15 to 35 mol% is more preferable.

［式（ａ１−４）中、
Ｒ^a32は、水素原子、ハロゲン原子、又は、ハロゲン原子を有してもよい炭素数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はそれぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^a36は、炭素数１〜２０の炭化水素基を表すか、Ｒ^a35及びＲ^a36は互いに結合して炭素数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 sometimes 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, the plurality of R ^a33 may be the same as or different from each other.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a36 may represent a hydrocarbon group having 1 to 20 carbon atoms, R ^a35 and R ^a36 are bonded to each other To form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced by —O— or —S—. Good. ]

^Examples of the alkyl group for R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.
Examples of the halogen atom for R ^a32 and R ^a33 include a fluorine atom, a chlorine atom, and a bromine atom.
The R ^a34 and R ^a35, include the same groups as R ¹⁴ and R ¹⁵ of formula (2).
R ^a36 is an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. Can be mentioned.

In formula (a1-2), R ^a32 is preferably a hydrogen atom.
R ^a33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group.
la is preferably 0 or 1, more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrocarbon group having 1 to 12 carbon atoms, more preferably a methyl group or an ethyl group.
The hydrocarbon group for ^Ra36 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. And more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and the alicyclic hydrocarbon group in R ^a36 are preferably unsubstituted. When the aromatic hydrocarbon group in R ^a36 has a substituent, the substituent is preferably an aryloxy group having 6 to 10 carbon atoms.

Examples of the monomer for deriving the structural unit monomer (a1-4) include monomers described in JP2010-204646A. Especially, the monomer respectively represented by Formula (a1-4-1)-Formula (a1-4-7) is preferable, and each is represented by Formula (a1-4-1)-Formula (a1-4-5). Monomers are more preferred.

  When resin (X1) has a structural unit (a1-4), the content rate is preferable with respect to all the structural units of resin (X1), 5-60 mol% is more preferable, and 10-50 mol% is more preferable. 15-40 mol% is more preferable.

式（ａ１−５）中、
Ｒ^a8は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｚ^ａ１は、単結合又は＊−（ＣＨ₂）_h3−ＣＯ−Ｌ⁵⁴−を表し、ｈ３は１〜４の整数を表し、＊は、Ｌ⁵¹との結合手を表す。
Ｌ⁵¹、Ｌ⁵²、Ｌ⁵³及びＬ⁵⁴は、それぞれ独立に、−Ｏ−又は−Ｓ−を表す。
ｓ１は、１〜３の整数を表す。
ｓ１’は、０〜３の整数を表す。 Examples of the structural unit having an acid labile group include a structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as “structural unit (a1-5)”).

In formula (a1-5),
R ^a8 represents a C 1-6 alkyl group optionally having 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 to L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent —O— or —S—.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3.

In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
One of L ⁵² and L ⁵³ is preferably —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—.

As a monomer which introduce | transduces structural unit (a1-5), the monomer described in Unexamined-Japanese-Patent No. 2010-61117 is mentioned, for example. Among these, monomers represented by formulas (a1-5-1) to (a1-5-4) are preferable, and monomers represented by formula (a1-5-1) or formula (a1-5-2) are preferable. Is more preferable.

  When the resin (X1) has the structural unit (a1-5), the content is preferably 1 to 40 mol%, more preferably 2 to 30 mol%, based on all the structural units of the resin (X1). 5 to 25 mol% is more preferable.

The structural unit (a1) having an acid labile group in the resin (X1) includes the structural unit (a1-0), the structural unit (a1-1), the structural unit (a1-2), and the structural unit (a1-5). ) Is preferably at least one selected from the group consisting of, and more preferably at least two, a combination of structural unit (a1-1) and structural unit (a1-2), structural unit (a1-1) and structural unit ( a1-5), a structural unit (a1-1) and a structural unit (a1-0), a structural unit (a1-2) and a structural unit (a1-0), and a structural unit (a1-5) And a combination of the structural unit (a1-0), a structural unit (a1-0), a structural unit (a1-0), a structural unit (a1-1), and a structural unit (a1-5) are more preferable. (A1-1) and The combination of granulation unit (a1-2), more preferably a combination of structural units (a1-1) and the structural unit (a1-5).

<Structural unit without acid labile group>
The structural unit (s) is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “monomer (s)”). As the monomer for deriving the structural unit (s) (hereinafter sometimes referred to as “monomer (s)”), a monomer having no acid labile group known in the resist field can be used.
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid labile group is preferable. A structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring and having no acid labile group If a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”) is used in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When a resist pattern is produced from the resist composition of the present invention, when a high energy beam such as a KrF excimer laser (248 nm), an electron beam or EUV (ultra-ultraviolet light) is used as an exposure light source, the structural unit (a2) It is preferable to use the structural unit (a2) having a phenolic hydroxy group. When an ArF excimer laser (193 nm) or the like is used, the structural unit (a2) having an alcoholic hydroxy group is preferable as the structural unit (a2), and the structural unit (a2-1) is more preferable. As a structural unit (a2), 1 type may be included independently and 2 or more types may be included.

式（ａ２−０−１）又は式（ａ２−０−２）で表されるものが好ましい。 Examples of the structural unit (a2-0) having a phenolic hydroxy group include the following structural units.

What is represented by Formula (a2-0-1) or Formula (a2-0-2) is preferable.

  Resin (X1) containing the structural unit (a2-0) is subjected to a polymerization reaction using a monomer in which the phenolic hydroxy group of the monomer that derives the structural unit (a2-0) is protected with a protective group, and then deprotected It can be manufactured by processing. However, when the deprotection treatment is performed, the acid labile group of the structural unit (a1) needs to be not significantly impaired. Examples of such protecting groups include acetyl groups.

  When resin (X1) has a structural unit (a2-0), the content rate is preferable with respect to all the structural units of resin (X1), and 10-60 mol% is more preferable, and 15-60 mol% is more preferable. 20-50 mol% is more preferable.

式（ａ２−１−１）〜式（ａ２−１−４）のいずれかで表される構造単位が好ましく、式式（ａ２−１−１）又は式（ａ２−１−３）で表される構造単位がより好ましい。
アルコール性ヒドロキシ基を有する構造単位（ａ２）を誘導するモノマーとしては、例えば、特開２０１０−２０４６４６号公報に記載されたモノマーが挙げられる。 Examples of the structural unit (a2-1) having an alcoholic hydroxy group include the following structural units.

A structural unit represented by any one of formula (a2-1-1) to formula (a2-1-4) is preferable, and is represented by formula (a2-1-1) or formula (a2-1-3). The structural unit is more preferable.
Examples of the monomer for deriving the structural unit (a2) having an alcoholic hydroxy group include monomers described in JP2010-204646A.

  When resin (X1) contains a structural unit (a2-1) structural unit, the content rate is 1-20 mol% normally with respect to all the structural units of resin (X1), Preferably it is 2-15 mol %, More preferably 2 to 10 mol%.

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. But you can. Preferably, a γ-butyrolactone ring or a bridged ring containing a γ-butyrolactone ring structure is used. Examples of the structural unit (a3) include the following structural units.

  As monomers for deriving the structural unit (a3), monomers described in JP 2010-204646 A, monomers described in JP 2000-122294 A, monomers described in JP 2012-41274 A are listed. Can be mentioned. As the structural unit (a3), the formula (a3-1-1) to the formula (a3-1-6), the formula (a3-2-1) to the formula (a3-2-4), and the formula (a3-3) 1) to a structural unit represented by any one of the formula (a3-3-4) and the formula (a3-4-1) to the formula (a3-4-6), the formula (a3-1-1), The structural unit represented by any one of the formula (a3-1-2) and the formula (a3-2-3) to the formula (a3-2-4) is more preferable, and the formula (a3-1-1) or the formula ( The structural unit represented by a3-2-3) is more preferable.

When the resin (X1) contains the structural unit (a3), the content thereof is usually 15 to 70 mol%, preferably 25 to 60 mol%, based on all the structural units of the resin (X1). More preferably, it is 30-60 mol%.
Further, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3), and the structural unit (a3-4) is the total content of the resin (X1). 15-70 mol% is preferable with respect to a structural unit, 25-60 mol% is more preferable, and 30-60 mol% is further more preferable.

<Other structural units (t)>
As the structural unit (t), in addition to the structural unit (a2) and the structural unit (a3), a structural unit having a halogen atom (hereinafter sometimes referred to as “structural unit (a4)”) and a non-leaving hydrocarbon group. And a structural unit (s) (hereinafter sometimes referred to as “structural unit (a5)”).

Examples of the structural unit (a4) include the structural units described below.

  When the resin (X1) has the structural unit (a4), the content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, based on all the structural units of the resin (X1). More preferred is ˜15 mol%.

<Structural unit (a5)>
Examples of the non-leaving hydrocarbon group that the structural unit (a5) has include a linear, branched, or cyclic hydrocarbon group. Especially, it is preferable that a structural unit (a5) is an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include the structural units described below.

  When the resin (X1) has the structural unit (a5), the content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, based on all structural units of the resin (X1). More preferred is ˜15 mol%.

（式中、Ｒ^２２２は、水素原子又はメチル基を表す。
＊は、塩構造との結合手を表す。） <Resin (X2)>
Next, the resin (X2) will be described.
The resin (X2) is a structural unit having a salt structure in the side chain, and includes a structural unit in which a cation part of the salt structure is bonded to the main chain (hereinafter sometimes referred to as the structural unit (X2)). .
The salt structure means a structure having a cation moiety and an anion moiety.
The main chain in the resin (X2) is represented by the following structure.

(Wherein R ²²² represents a hydrogen atom or a methyl group.
* Represents a bond with a salt structure. )

The anion site is not particularly limited, and is preferably a monovalent anion site, more preferably an anion site containing a sulfonate ion.
As an anion site | part, the anion site | part containing a hydrocarbon group is mentioned. Carbon number of this hydrocarbon group is 1-36 normally, Preferably it is 1-30, More preferably, it is 1-24. The —CH ₂ — group contained in the hydrocarbon group may be replaced by —O— or —CO ₂ —, and the hydrogen atom contained in the hydrocarbon group is substituted with a fluorine atom or a hydroxyl group. Also good.
Examples of the hydrocarbon group include an alkyl group and an aromatic hydrocarbon group.
Examples of the alkyl group include linear or branched alkenyl, linear or branched alkynyl, monocyclic or polycyclic alicyclic hydrocarbon groups, and two or more of these groups are combined. It may be a thing.
Examples of the aromatic hydrocarbon group include monocyclic and polycyclic structures, and ═CH— of the aromatic hydrocarbon group may be replaced by ═N—, and These carbon atoms may have a substituent.
The anion moiety is preferably a moiety having at least one selected from a fluorine atom, a carbonyl group, an ester bond and an ether bond, and more preferably a moiety having a fluorine atom or a carbonyl group.

The cation moiety is not particularly limited, and is preferably a monovalent cation moiety, more preferably a cation moiety containing an iodonium ion and a cation moiety containing a sulfonium ion.
Examples of the cation moiety include a cation moiety containing a hydrocarbon group. Carbon number of this hydrocarbon group is 1-18 normally, Preferably it is 1-15, More preferably, it is 1-12.
As a hydrocarbon group, the thing similar to the hydrocarbon group in an anion site | part is mentioned. Preferably, it is an aromatic hydrocarbon group.

The combination of an anion site and a cation site can be arbitrarily combined. As a combination of an anion site and a cation site,
A combination of an anion moiety containing a sulfonate ion and a cation moiety containing an iodonium ion and a combination of an anion moiety containing a sulfonate ion and a cation moiety containing a sulfonium ion are preferred,
A combination of an anion moiety containing a sulfonate ion and a cation moiety containing a sulfonium ion is more preferred.

The structural unit (X2) may be a monovalent salt structure or a divalent salt structure, and the valence is not limited. The structural unit (X2) is preferably a monovalent salt structure.
The structural unit (X2) preferably has a structure that generates an acid by the action of light or an acid, and more preferably has a structure that generates an acid by the action of light.
The cation moiety in the structural unit (X2) and the cation moiety in the structural unit (X1) preferably have a common structure.

［式（ＩＩ）中、
Ｒ^４及Ｒ^５は、それぞれ独立に、置換基を有していてもよい炭素数１〜１８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−で置き換わっていてもよい。Ｒ^４とＲ^５とは、互いに結合して環を形成してもよく、該環に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−、−ＣＯ−又は＝Ｎ−に置き換わっていてもよい。
Ｒ^６は、置換基を有していてもよい炭素数１〜３６の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−、−ＣＯ−又は−ＮＲ^１１−で置き換わっていてもよく、Ｒ^１１は炭素数１〜６のアルキル基を表す。
Ｌ^２は、炭素数１〜１８の２価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−で置き換わっていてもよい。
Ｄ^＋は、ヨードニウムイオン又はスルホニウムイオンを表す。
＊は、主鎖との結合手を表す。］ The structural unit (X2) preferably has a structure represented by the formula (II) (hereinafter sometimes referred to as structural unit (II)).

[In the formula (II),
R ⁴ and R ⁵ each independently represents a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and —CH ₂ — contained in the hydrocarbon group is —O— or — It may be replaced by CO-. R ⁴ and R ⁵ may combine with each other to form a ring, and —CH ₂ — contained in the ring is replaced with —O—, —SO ₂ —, —CO— or ═N—. May be.
R ⁶ represents a C1-36 saturated hydrocarbon group which may have a substituent, and —CH ₂ — contained in the saturated hydrocarbon group is —O—, —SO ₂ —, — CO— or —NR ¹¹ — may be substituted, and R ¹¹ represents an alkyl group having 1 to 6 carbon atoms.
L ² represents a divalent hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the hydrocarbon group may be replaced by —O— or —CO—.
D ⁺ represents an iodonium ion or a sulfonium ion.
* Represents a bond with the main chain. ]

Examples of the hydrocarbon group having 1 to 18 carbon atoms include a linear or branched alkenyl group, a monocyclic or polycyclic alicyclic hydrocarbon group, and an aromatic hydrocarbon group, and an aromatic hydrocarbon group. It is preferable to contain. Examples of the aromatic hydrogen group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl. Group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, pyridyl group, imidazolium group, indole group and the like.
Examples of the substituent for the hydrocarbon group having 1 to 18 carbon atoms include a hydroxy group, a halogen atom, a cyano group, a nitro group, a carboxy group, an alkoxy group having 1 to 8 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, and carbon. An acyl group having 1 to 8 carbon atoms, an acyloxy group having 2 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 9 carbon atoms, an alkoxycarbonyloxy group having 2 to 9 carbon atoms, an amino group, an acylamino group having 1 to 8 carbon atoms, Examples thereof include an alkoxycarbonylamino group having 2 to 9 carbon atoms and an aryloxycarbonyl group having 7 to 18 carbon atoms.

Examples of the alkoxy group having 1 to 8 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group and octyloxy group.
Examples of the aryloxy group having 6 to 12 carbon atoms include a phenyloxy group, a tolyloxy group, and a naphthyloxy group.
Examples of the acyl group having 1 to 8 carbon atoms include formyl group, acetyl group, propionyl group and butyryl group.
Examples of the acyloxy group having 2 to 8 carbon atoms include formyloxy group, acetyloxy group, propionyloxy group, and butyryloxy group.
Examples of the alkoxycarbonyl group having 2 to 9 carbon atoms include methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group, pentyloxycarbonyl group, hexyloxycarbonyl group and the like.
Examples of the alkoxycarbonyloxy group having 2 to 9 carbon atoms include a methoxycarbonyloxy group, an ethoxycarbonyloxy group, a propoxycarbonyloxy group, a butoxycarbonyloxy group, a pentyloxycarbonyloxy group, and a hexyloxycarbonyloxy group.
Examples of the acylamino group having 1 to 8 carbon atoms include formylamino group, acetylamino group, propionylamino group, and butyrylamino group.
Examples of the C2-C9 alkoxycarbonylamino group include a methoxycarbonylamino group, an ethoxycarbonylamino group, a propoxycarbonylamino group, a butoxycarbonylamino group, a pentyloxycarbonylamino group, and a hexyloxycarbonylamino group.
Examples of the aryloxycarbonyl group having 7 to 18 carbon atoms include a phenyloxycarbonyl group, a tolyloxycarbonyl group, and a naphthyloxycarbonyl group.

Examples of the ring formed by combining R ⁴ and R ⁵ with each other include a heterocyclic ring containing at least one sulfur atom. Examples thereof include a ring represented by the following formula.

Examples of the substituent that the hydrocarbon group having 1 to 18 carbon atoms represented by R ⁴ and R ⁵ may have include an alicyclic hydrocarbon group having 3 to 12 carbon atoms, a hydroxy group, and 1 to 1 carbon atom. And an alkoxy group having 8 to 8 carbon atoms, an acyl group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 9 carbon atoms, and an acyloxy group having 2 to 8 carbon atoms.
The alicyclic hydrocarbon group having 3 to 12 carbon atoms may be monocyclic or polycyclic. Examples of the monocyclic aliphatic hydrocarbon group include a cyclobutyl 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 and a norbornyl group.
Examples of the acyl group having 1 to 8 carbon atoms include formyl group, acetyl group, propionyl group and butyryl group.
Examples of the alkoxy group having 1 to 8 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group and octyloxy group.
Examples of the alkoxycarbonyl group having 2 to 9 carbon atoms include methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group, pentyloxycarbonyl group, hexyloxycarbonyl group and the like.
Examples of the acyloxy group having 2 to 8 carbon atoms include formyloxy group, acetyloxy group, propionyloxy group, and butyryloxy group.

Examples of the divalent hydrocarbon group having 1 to 36 carbon atoms represented by R ⁶ include a linear alkenyl group, a branched alkenyl group, and a monocyclic or polycyclic alicyclic saturated hydrocarbon group. A combination of two or more of these groups may be used.
Examples of the alkyl group having 1 to 6 carbon atoms represented by R ¹¹ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.
A fluorine atom is mentioned as a substituent which the C1-C36 bivalent hydrocarbon group represented by R < ⁶ > may have.

R ⁴ and R ⁵ are preferably an alicyclic hydrocarbon group having 3 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 12 carbon atoms, or bonded to each other to form a ring, and has 6 to 12 carbon atoms. It is more preferable that an aromatic hydrocarbon group or each other is bonded to form a ring.
At least one —CH ₂ — contained in the saturated hydrocarbon group having 1 to 36 carbon atoms represented by R ⁶ is preferably replaced by —CO—, and at least one hydrogen atom is preferably replaced by a fluorine atom. preferable.
It is preferable that at least one —CH ₂ — contained in the saturated hydrocarbon group having 1 to 18 carbon atoms represented by L ² is replaced with —CO—.
D ⁺ is preferably a sulfonium ion.

［式（ＩＩａ）中、Ｑ^３及びＱ^４は、それぞれ独立して、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
ｎ＝１〜３の整数を表す。
Ｘ^３は、単結合又は炭素数１〜１２の２価の飽和炭化水素基を表す。
Ｗ^２は、置換基を有していてもよい炭素数３〜１８の２価の脂環式炭化水素基を表す。該脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−、−ＣＯ−又は−ＮＲ^１１−に置き換わっていてもよい。］ <Anion site>
The anion moiety in the structural unit (II) is preferably an anion moiety represented by the formula (IIa) (hereinafter sometimes referred to as the structural unit (IIa)).

[In Formula (IIa), Q ³ and Q ⁴ each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
n represents an integer of 1 to 3.
X ³ represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
W ² represents a divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ —, —CO— or —NR ¹¹ —. ]

Examples of the perfluoroalkyl group for Q ³ and Q ⁴ include the same groups as those represented by Q ¹ and Q ² in the structural unit (Ia).
Q ³ and Q ⁴ are preferably the same group.
Q ³ and Q ⁴ are preferably each independently a fluorine atom or a trifluoromethyl group, and more preferably a fluorine atom.
n represents an integer of 1 to 10.

Examples of the divalent saturated hydrocarbon group for X ³ include the same groups as those represented by X ¹ in the structural unit (Ia).
Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO— include the same groups as those represented by X ¹ in the structural unit (Ia).
X ³ is preferably a group represented by the formula (X1-1).

Examples of the divalent alicyclic hydrocarbon group for W ² include the same groups as those represented by W ¹ in the structural unit (Ia).
W ² is preferably a group represented by any one of formula (Y1 ′) to formula (Y19 ′), and more preferably formula (Y4 ′), formula (Y9 ′), formula (Y10 ′), formula It is a group represented by (Y11 ′), Formula (Y14 ′), Formula (Y15 ′) or Formula (Y19 ′), and more preferably Formula (Y4 ′), Formula (Y9 ′), and Formula (Y10 ′). Or it is group represented by a formula (Y11 ').

The substituent that the divalent alicyclic hydrocarbon group represented by W ² may have may be a hydroxy group, an aromatic hydrocarbon group having 6 to 12 carbon atoms, or a halogen atom. Good alkyl groups having 1 to 6 carbon atoms can be mentioned.
Examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms that W ² has include a phenyl group, a naphthyl group, and a tolyl group.
Examples of the alkyl group having 1 to 6 carbon atoms that may have a halogen atom that W ² has include a trifluoromethyl group, a tetrafluoroethyl group, and the like, and a carbon that may have the halogen atom. —CH ₂ — contained in the alkyl group of formulas 1 to 6 may be replaced by —O— or —CO—.

W ² is particularly preferably a divalent group represented by the following formula.

Examples of the anion moiety in the structural unit (II) include anion moieties represented by the formulas (IIa-1) to (IIa-15), and the formula (IIa-1), the formula (IIa-2), or the formula ( The anion moiety represented by IIa-8) is preferred.

［式（ＩＩｂ）中、Ｌ^３は、単結合又は炭素数１〜１６の２価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−で置き換わっていてもよい。
Ｒ^４及びＲ^５は、上記と同じ意味を表す。］ <Cation site>
The cation moiety in the structural unit (II) is preferably a structure represented by the formula (IIb) (hereinafter sometimes referred to as the structural unit (IIb)).

[In Formula (IIb), L ³ represents a single bond or a divalent hydrocarbon group having 1 to 16 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O— or —CO—. It may be replaced.
R ⁴ and R ⁵ represent the same meaning as described above. ]

Examples of the divalent hydrocarbon group of L ³ include a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, and a divalent combination of two or more of these. Groups.
Examples of the divalent aliphatic hydrocarbon group 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, and a 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, Butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4- Examples thereof include linear or branched alkanediyl groups of diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group.
Examples of the divalent aromatic hydrocarbon group include a phenylenediyl group, a naphthalenediyl group, and an anthracenediyl group.

Examples of the divalent alicyclic hydrocarbon group of L ³ include groups represented by the above formula (Y1 ′) to formula (Y11 ′). The groups in which —CH ₂ — contained in the alicyclic hydrocarbon group is replaced by —O—, —SO ₂ — or —CO— are represented by formulas (Y12 ′) to (Y26 ′). Group to be used.

The divalent alicyclic hydrocarbon group of L ³ is preferably a group represented by any one of the formulas (Y1 ′) to (Y19 ′), more preferably the formula (Y11 ′) and the formula (Y14 ′), A group represented by formula (Y15 ′) or formula (Y19 ′), more preferably a group represented by formula (Y11 ′) or formula (Y14 ′).

Examples of the substituent that the divalent hydrocarbon group represented by L ³ may have include a halogen atom, a hydroxy group, and a nitro group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

L ³ is preferably a divalent group containing an aromatic hydrocarbon group, more preferably a divalent aromatic hydrocarbon group.

［式（ＩＩｂ−１）中、
Ｐ^２２、Ｐ^２３及びＰ^２４は、互いに独立に、ヒドロキシ基、ハロゲン原子、シアノ基、ニトロ基、カルボキシ基、炭素数１〜１２の脂肪族炭化水素基、炭素数１〜８のアルコキシ基、アリールオキシ基、炭素数１〜８のアシル基、炭素数２〜８のアシルオキシ基、炭素数２〜９のアルコキシカルボニル基、炭素数２〜９のアルコキシカルボニルオキシ基、アミノ基、炭素数１〜８のアシルアミノ基、炭素数２〜９のアルコキシカルボニルアミノ基、炭素数７〜１８のアリールオキシカルボニル基を表すか、隣接する２つが一緒になって、硫黄原子を含む環を形成していてもよい。
ｘ^２２及びｘ^２４は、０〜５の整数を表す。
ｘ^２３は、０〜４の整数を表す。
Ｌ^４は、単結合又は炭素数１〜１０の２価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−で置き換わっていてもよい。］ The cation moiety represented by the formula (IIb) is more preferably a cation moiety represented by the formula (IIb-1).

[In the formula (IIb-1),
P ²² , P ²³ and P ²⁴ are each independently a hydroxy group, a halogen atom, a cyano group, a nitro group, a carboxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, Aryloxy group, C1-C8 acyl group, C2-C8 acyloxy group, C2-C9 alkoxycarbonyl group, C2-C9 alkoxycarbonyloxy group, amino group, C1-C1 8 represents an acylamino group, an alkoxycarbonylamino group having 2 to 9 carbon atoms, an aryloxycarbonyl group having 7 to 18 carbon atoms, or two adjacent groups together form a ring containing a sulfur atom Good.
x ²² and ^{x 24} is an integer of 0-5.
x ²³ represents an integer of 0 to 4.
L ⁴ represents a single bond or a C 1-10 divalent hydrocarbon group, and —CH ₂ — contained in the hydrocarbon group may be replaced by —O— or —CO—. ]

P ²² , P ²³ and P ²⁴ are preferably a hydroxy group, a halogen atom, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an acyl group having 1 to 8 carbon atoms. .
x ²² is preferably an integer of 0 to 2.
x ²⁴ is preferably an integer of 0 to 2.
x ²³ is preferably an integer of 0 to 2.

Examples of the ring formed by combining two adjacent ones include the rings shown below.

Examples of the cation moiety in the structural unit (II) include cation moieties represented by the formula (IIb-1-1) to the formula (IIb-1-15), preferably the formula (IIb-1-1) or It is a cation moiety represented by the formula (IIb-1-4).

  As the structural unit (II), an anion moiety represented by formula (IIa-1) to formula (IIa-18) and a cation represented by formula (IIb-1-1) to formula (IIb-1-15) Examples of the structural units shown in Tables 3 and 4 are given. The structural unit (II) is preferably the formula (II-1), the formula (II-4), the formula (II-16), the formula (II-19), the formula (II-31) or the formula (II-34). Is a structural unit represented by

The resin (X2) may contain a structural unit other than the structural unit (X2). Examples of other structural units include other structural units that the resin (X1) may contain in addition to the structural unit (X1).
Either the resin (X1) or the resin (X2) contains a structural unit having an acid labile group, and both the resin (X1) and the resin (X2) contain a structural unit having an acid labile group. preferable.
Content of structural unit (X2) is 0.1-50 mol% normally with respect to the whole quantity of resin (X2), Preferably it is 1-30 mol%, More preferably, it is 2-20 mol%. .

Resin composition (A) contains resin (X1) and resin (X2), and may contain other resins. Other resins are not particularly limited as long as they are known resins.
In the resin composition, the content ratio of the resin (X1) and the resin (X2) is usually resin (X1): resin (X2) = 20: 1 to 1:20, preferably 10: 1 to 1 on a mass basis. 1:10, more preferably 1: 6 to 6: 1.
In the resin composition, the content of the structural unit having a salt structure in the side chain is usually 0.1 to 50% by mole, preferably 1 to 30%, more preferably 2 to 2% with respect to the total amount of the resin. 20%.
The resin composition (A) preferably includes a combination of the resin (X1) having the structural unit (I) and the resin (X2) having the structural unit (II) described in Table 5 and Table 6. It is a resin composition.

<Resist composition>
The resist composition of the present invention comprises a resin composition (A) and a solvent (hereinafter sometimes referred to as solvent (E)) or an acid generator (hereinafter sometimes referred to as acid generator (B)). contains. Furthermore, a basic compound (hereinafter sometimes referred to as a basic compound (C)) may be included.

<Solvent (E)>
The content of the solvent (E) is usually 90% by mass or more in the resist composition, preferably 92% by mass or more, more preferably 94% by mass or more, for example, 99.9% by mass or less, preferably 99% by mass. It is as follows. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

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

<Acid generator (B)>
The acid generator means a compound that generates an acid by the action of light. The acid generator (B) may be nonionic or ionic. Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonate) and sulfones (for example, 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, JP-A-62-153853, JP-A-63-146029, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712 A known acid generator that generates an acid by radiation described in the above can be used, and an ionic acid generator or a nonionic generator may be used, but an ionic acid generator is preferable. Examples of the ionic acid generator include ionic acid generators composed of a combination of a known cation and a known anion.

As an acid generator (B), the salt represented by either of Formula (B1-1)-Formula (B1-20) is mentioned. Among them, those containing a triarylsulfonium cation are preferable. Formula (B1-1), Formula (B1-2), Formula (B1-3), Formula (B1-6), Formula (B1-7), Formula (B1- 11) A salt represented by any one of formula (B1-12), formula (B1-13) and formula (B1-14) is more preferred.

When the resist composition of the present invention contains an acid generator (B), the content thereof is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 100 parts by mass of the total amount of the resin. 30 parts by mass or less (more preferably 25 parts by mass or less).
In the resist composition of the present invention, the acid generator (B) may contain two or more kinds.

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

  As the basic compound (C), 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, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexyl Amine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine , Ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenyl Ethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, 2,2′-methylenebisaniline, imida , 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'-dipycolylamine, bipyridine and the like, preferably diisopropylaniline, particularly preferably 2,6- Diisopropylaniline is mentioned.

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

The acidity in a salt having a weaker acidity than the acid generated from the acid generator (B) is represented by an acid dissociation constant (pKa). The salt having a lower acidity than the acid generated from the acid generator (B) is a salt in which the acid dissociation constant of the acid generated from the salt is usually -3 <pKa, preferably -1 <pKa <7. A salt, more preferably a salt of 0 <pKa <5.
Examples of the salt having a weaker acidity than the acid generated from the acid generator (B) include salts represented by the following formulas, JP2012-229206A, JP2012-6908A, and JP2012-72109A. And salts described in JP-A-2011-39502 and 2011-191745.

  The content of the basic compound (C) is preferably 0.01 to 5% by mass and more preferably 0.01 to 3% by mass in the solid content of the resist composition.

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

<Method for producing resist composition>
The resist composition of the present invention comprises a resin (X1) and a resin (X2) / or a resin other than the resins (X1) and (X2) used as necessary, a solvent (E), an acid generator (B ), The basic compound (C) and the other component (F) can be prepared. The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select the suitable temperature range from the range of 10-40 degreeC according to the solubility with respect to the solvent (E), such as a kind, etc. of resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method for producing resist pattern>
<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) The process of apply | coating the resist composition of this invention on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer using an exposure machine;
(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.

By drying the composition after coating, the solvent is removed and a composition layer is formed. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or using a decompression device. The heating temperature is preferably 50 to 200 ° C., for example, and the heating time is preferably 10 to 180 seconds, for example. The pressure during drying under reduced pressure is preferably about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser) Etc.) Using various lasers such as those that convert wavelength of laser light from the laser and emit harmonic laser light in the far-ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams or extreme ultraviolet light (EUV), etc. Can do. In this specification, the irradiation of these radiations may be collectively referred to as “exposure”. At the time of exposure, exposure is usually performed through a mask corresponding to a required pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask.

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

  The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., for example, and the development time is preferably 5 to 300 seconds, for example. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline). The alkali developer may contain a surfactant.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove the water remaining on the substrate and the pattern.

In the case of producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
Organic solvents 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.
In the organic developer, the content of the organic solvent 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 still more preferably only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. In the organic developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and substantially butyl acetate and / or 2 -More preferred is heptanone alone.
The organic developer may contain a surfactant. The organic developer may contain a trace 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 developed resist pattern with a rinse solution. The rinsing 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 solution remaining on the substrate and the pattern.

<Application>
The resist composition of the present invention is a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, particularly a liquid. It is suitable as a resist composition for immersion exposure and useful for fine processing of semiconductors.

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

Synthesis Example 1 [Synthesis of Resin Composition (A)]
The compounds (monomers) used for the synthesis of the resin composition (A) are shown below. (IX-1) was synthesized by the method described in JP2007-197718, and (IX-2) was synthesized by the method described in JP2011-37835A. Hereinafter, these compounds are referred to as “monomer (a1-1-2)” or the like according to the formula number.

Synthesis Example 2 [Synthesis of Resin X1-1]
As the monomer, monomer (a1-1-3), monomer (a1-2-7), monomer (a2-1-1), monomer (a3-2-3), monomer (a3-1-1) and monomer ( IX-1), and its molar ratio [monomer (a1-1-3): monomer (a1-2-7): monomer (a2-1-1): monomer (a3-2-3): monomer (a3 -1-1): monomer (IX-1)] was mixed at 28: 15: 5: 15: 32: 5, and methyl ethyl ketone 1.5 times the total monomer amount was added to obtain a solution. As initiators, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of monomers, and heated at 75 ° C. for about 5 hours. . The obtained resin solution was poured into a large amount of a mixed solvent of n-heptane and 2-propanol (mass ratio n-heptane: 2-propanol = 4: 1) to precipitate the resin. This resin was filtered and collected. The recovered resin is stirred in 2-propanol, and then filtered and recovered, and the purification is repeated three times to obtain a copolymer having a weight average molecular weight of 5.0 × 10 ³ in a yield of 75%. Got in. This copolymer has the following structural units and is designated as resin X1-1.

Synthesis Example 3 [Synthesis of Resin X1-2]
As the monomer, monomer (a1-1-3), monomer (a1-2-7), monomer (a2-1-1), monomer (a3-2-3), monomer (a3-1-1) and monomer ( IX-3) and its molar ratio [monomer (a1-1-3): monomer (a1-2-7): monomer (a2-1-1): monomer (a3-2-3): monomer (a3 -1-1): monomer (IX-3)] was 28: 15: 5: 15: 32: 5, and 1.5 mass times methyl ethyl ketone as the total amount of monomers was added to prepare a solution. As initiators, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of monomers, and heated at 75 ° C. for about 5 hours. . The obtained resin solution was poured into a large amount of a mixed solvent of n-heptane and 2-propanol (mass ratio n-heptane: 2-propanol = 4: 1) to precipitate the resin. This resin was filtered and collected. The recovered resin is stirred in 2-propanol, filtered and recovered, and purified three times to obtain a copolymer having a weight average molecular weight of 4.5 × 10 ³ with a yield of 75%. Got in. This copolymer has the following structural units and is designated as resin X1-2.

Synthesis Example 4 [Synthesis of Resin X2-1]
As the monomer, monomer (a1-1-3), monomer (a1-2-7), monomer (a2-1-1), monomer (a3-2-3), monomer (a3-1-1) and monomer ( IX-2) and its molar ratio [monomer (a1-1-3): monomer (a1-2-7): monomer (a2-1-1): monomer (a3-2-3): monomer (a3 -1-1): monomer (IX-2)] was mixed at 28: 15: 5: 15: 32: 5, and 1.5 mass times of methyl ethyl ketone as a total monomer amount was added to obtain a solution. As initiators, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of monomers, and heated at 75 ° C. for about 5 hours. . The obtained resin solution was poured into a large amount of a mixed solvent of n-heptane and 2-propanol (mass ratio n-heptane: 2-propanol = 4: 1) to precipitate the resin. This resin was filtered and collected. The recovered resin is stirred in 2-propanol, then filtered and recovered, and the purification is repeated three times to obtain a copolymer having a weight average molecular weight of 5.0 × 10 ³ in a yield of 71%. Got in. This copolymer has the following structural units and is designated as resin X2-1.

Synthesis Example 5 [Synthesis of Resin X2-2]
As the monomer, the monomer (a1-1-2), the monomer (a2-1-1), the monomer (a3-2-3), the monomer (a3-1-1) and the monomer (IX-2) The ratio [monomer (a1-1-2): monomer (a2-1-1): monomer (a3-2-3): monomer (a3-1-1): monomer (IX-2)] is 35:12: It mixed so that it might become 23:20:10, and 1.5 mass times methyl ethyl ketone of the total monomer amount was added, and it was set as the solution. As initiators, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added in an amount of 1.2 mol% and 3.6 mol%, respectively, based on the total amount of monomers, and heated at 75 ° C. for about 5 hours. . The obtained resin solution was poured into a large amount of a mixed solvent of n-heptane and 2-propanol (mass ratio n-heptane: 2-propanol = 4: 1) to precipitate the resin. This resin was filtered and collected. The recovered resin is stirred in 2-propanol and then filtered and recovered three times for purification. A copolymer having a weight average molecular weight of 6.0 × 10 ³ is obtained in a yield of 68%. Got in. This copolymer has the following structural units and is referred to as Resin X2-2.

Synthesis Example 6 [Synthesis of Resin X1-3]
As the monomer, monomer (a1-1-4) and monomer (IX-3) are used, and mixed so that the molar ratio [monomer (a1-1-4): monomer (IX-3)] is 70:30. Then, 1.5 mass times methanol of the total monomer amount was added to make a solution. Thereto, 0.4 mol% of azobis (2,4-dimethylvaleronitrile) was added as an initiator with respect to the total amount of monomers, and heated at 60 ° C. for about 5 hours. The obtained resin solution was poured into a large amount of a mixed solvent of n-heptane and 2-propanol (mass ratio n-heptane: 2-propanol = 4: 1) to precipitate the resin. This resin was filtered and collected. The recovered resin was redissolved in tetrahydrofuran and poured into a large amount of n-heptane to reprecipitate the resin. This resin was filtered and collected, then stirred and filtered in n-heptane, and a copolymer having a weight average molecular weight of 4.0 × 10 ³ was obtained in a yield of 88%. This copolymer has the following structural units and is designated as resin X1-3.

Examples 1-8 and Comparative Examples 1-3
(Preparation of resist composition)
Each of the components shown below was mixed in parts by mass shown in Table 7 and dissolved in a solvent, and then filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin>
X1-1: Resin X1-1
X1-2: Resin X1-2
X2-1: Resin X2-1
X2-2: Resin X2-2
X1-3: Resin X1-3

Ｂ１−２１：式（Ｂ１−２１）で表される塩；特開２０１１−１２６８６９号公報記載の方法で合成

＜クエンチャー（Ｃ）＞
Ｃ１：式（Ｃ９−６）で表される塩；特開２０１１−３９５０２号公報記載の方法で合成
＜溶剤（Ｅ）＞
プロピレングリコールモノメチルエーテルアセテート ４００部
プロピレングリコールモノメチルエーテル １５０部
γ−ブチロラクトン ５部 <Acid generator (B)>
B1-3: salt represented by formula (B1-3)

B1-21: a salt represented by the formula (B1-21); synthesized by the method described in JP2011-126869A

<Quencher (C)>
C1: salt represented by formula (C9-6); synthesized by the method described in JP2011-39502A <solvent (E)>
Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 150 parts γ-butyrolactone 5 parts

(Manufacture of resist pattern)
An 8-inch silicon wafer was treated with hexamethyldisilazane at 90 ° C. for 60 seconds on a direct hot plate. This silicon wafer was spin-coated with a resist composition so that the film thickness of the composition layer was 0.035 μm.
Thereafter, the composition layer was formed by pre-baking on a direct hot plate for 60 seconds at the temperature shown in the “PB” column of Table 1. The composition layer formed on the wafer was exposed through a mask for forming a line-and-space pattern (line width 24 nm, pitch 48 nm) by using an EUV exposure machine and changing the exposure amount stepwise. .
After exposure, post exposure bake on the hot plate at the temperature shown in the “PEB” column of Table 1 for 60 seconds, and further paddle development for 60 seconds with 2.38% tetramethylammonium hydroxide aqueous solution, A resist pattern was obtained.

  Resolution evaluation: The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the minimum dimension at which no pattern collapse occurred was defined as a collapse margin. In a positive resist pattern, the line width tends to decrease as the exposure amount increases. However, as the resolution of the resist pattern increases, the line width is less likely to collapse. That is, it can be said that the smaller the fall margin value, the higher the resolution because a resist pattern with a smaller line width can be manufactured. The results are shown in Table 8.

  The resist composition containing the resin composition of the present invention is suitable for fine processing of a semiconductor because the resolution of the resulting resist pattern is good.

Claims (17)

The resin composition containing following (X1) and (X2).
(X1) a resin containing a structural unit having a salt structure in the side chain, wherein the anion portion of the salt structure is bonded to the main chain (X2) a resin containing a structural unit having a salt structure in the side chain A resin in which the cation portion of the salt structure is bonded to the main chain   The resin composition according to claim 1, wherein the resin is a resin that generates an acid by the action of an acid or light.   The resin composition according to claim 1 or 2, wherein the cation moiety having a salt structure in (X1) and the cation moiety having a salt structure in (X2) have a common structure.   The resin composition according to claim 3, wherein the common structure of the cation moiety of the salt structure in (X1) and the cation moiety of the salt structure in (X2) is a structure containing a cyclic hydrocarbon group.   The resin composition according to any one of claims 1 to 4, wherein the cation moiety is a moiety containing an iodonium ion or a sulfonium ion.   The resin composition according to claim 1, wherein the anion moiety is a moiety containing a sulfonate ion or a carboxylate ion.   The resin composition according to any one of claims 1 to 6, wherein the salt structure is bonded to the main chain via a linking group containing at least one carbonyl group.   The resin composition according to any one of claims 1 to 7, wherein a content ratio of (X1) to (X2) ((X1) :( X2)) is 20: 1 to 1:20 on a mass basis.   The resin composition according to any one of claims 1 to 8, wherein the structural unit having a salt structure in the side chain is 0.1 to 50 mol% with respect to all the structural units of the resin.   The resin composition according to any one of claims 1 to 9, wherein the salt structure in (X1) is 0.1 to 50 mol% based on all structural units of the resin of (X1).   The resin composition according to any one of claims 1 to 10, wherein the salt structure in (X2) is 0.1 to 50 mol% with respect to all structural units of the resin of (X2).   The resin composition according to any one of claims 1 to 11, wherein at least one of the resins (X1) and (X2) is a resin containing a structural unit having an acid labile group. The resin composition according to any one of claims 1 to 12, wherein the salt structure in (X1) is a structure represented by the formula (I).

[In the formula (I),
L ¹ represents an optionally substituted divalent saturated hydrocarbon group having 1 to 36 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group is —O— or —SO _2. -Or -CO- may be substituted, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted by a fluorine atom.
R ¹ , R ² and R ³ each independently represent a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and —CH ₂ — contained in the hydrocarbon group is —O -Or -CO- may be substituted. R ¹ and R ² may combine with each other to form a ring, and —CH ₂ — contained in the ring is replaced by —O—, —SO ₂ —, —CO— or ═N—. May be.
A ⁺ represents an iodonium ion or a sulfonium ion.
* Represents a bond with the main chain. ]] The resin composition according to claim 1, wherein the salt structure in (X2) is a structure represented by the formula (II).

[In the formula (II),
R ⁴ and R ⁵ each independently represents a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and —CH ₂ — contained in the hydrocarbon group is —O— or — It may be replaced by CO-. R ⁴ and R ⁵ may combine with each other to form a ring, and —CH ₂ — contained in the ring is replaced with —O—, —SO ₂ —, —CO— or ═N—. May be.
R ⁶ represents a C1-36 saturated hydrocarbon group which may have a substituent, and —CH ₂ — contained in the saturated hydrocarbon group is —O—, —SO ₂ —, — CO— or —NR ¹¹ — may be substituted, and R ¹¹ represents an alkyl group having 1 to 6 carbon atoms.
L ² represents a divalent hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the hydrocarbon group may be replaced by —O— or —CO—.
D ⁺ represents an iodonium ion or a sulfonium ion.
* Represents a bond with the main chain. ]   A resist composition comprising the resin composition according to claim 1 and a solvent.   A resist composition comprising the resin composition or resist composition according to claim 1 and an acid generator.   A resist composition comprising the resin composition or resist composition according to claim 1 and a basic compound.