JP6252157B2 - Resist composition and method for producing resist pattern - Google Patents

Description

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

Patent Document 1 describes a resist composition using a resin composed of a combination of the following structural units and triphenylsulfonium hexafluoroantimonate as an acid generator.

JP 2007-284381 A

  In the resist pattern formed by the above resist composition, the shape may not always be satisfied.

［式（Ｉ）中、
Ｒ¹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。
Ｌ¹は、単結合又は炭素数１〜１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−に置き換わってもよい。
Ｒ²は、ハロゲン原子を有してもよい炭素数１〜１０の炭化水素基を表す。
Ｒ³は、炭素数１〜１０のアルキル基、ハロゲン原子又は水酸基を表す。
Ｗは、炭素数５〜１８の炭化水素環を表し、該炭化水素環に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わってもよい。
ｌは０〜４の整数を表す。
ｍは１〜３の整数を表す。
ｎは０〜１０の整数を表す。ｎが２以上の時、複数のＲ³は、同じでも異なっていてもよい。］

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１〜２４の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の１価の脂環式炭化水素基を表し、該アルキル基及び該１価の脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−に置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］
［２］ Ｌ¹が、単結合である［１］記載のレジスト組成物。
［３］ Ｗが、アダマンタン環である［１］又は［２］記載のレジスト組成物。
［４］ さらに、フッ素原子を有し、かつ、酸不安定基を有する構造単位を含まない樹脂（Ａ２）を含有する［１］〜［３］のいずれかに記載のレジスト組成物。
［５］ 前記樹脂（Ａ２）は、式(ａ４−１)で表される構造単位からなる樹脂である［４］に記載のレジスト組成物。

［式（ａ４−１）中、
Ｒ^a41は、炭素数１〜１２の１価の炭化水素基を表し、該炭化水素基を含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
Ａ^a41は、置換基を有していてもよい炭素数１〜６のアルカンジイル基又は式（ａ−ｇ１）

（式（ａ−ｇ１）中、ｓは０又は１を表す。
Ａ^a42及びＡ^a44は、それぞれ独立に、置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基を表す。
Ａ^a43は、置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基又は単結合を表す。
Ｘ^a41及びＸ^a42は、それぞれ独立に、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
ただし、Ａ^a42、Ａ^a43、Ａ^a44、Ｘ^a41及びＸ^a42の炭素数の合計は７以下である。）
で表される基を表す。
Ｒ^a42は、置換基を有していてもよい炭素数１〜２０の炭化水素基であって、そのメチレン基がカルボニルオキシ基又はオキシカルボニル基で置換されてもよい炭化水素基を表す。
ただし、Ａ^a41及びＲ^a４２のうち少なくとも一方は、フッ素原子を有する基である。］
［６］さらに、式（Ｂ１）で表される酸発生剤から発生する酸よりも酸性度の弱い塩を含有する［１］〜［５］のいずれかに記載のレジスト組成物。 The present invention includes the following inventions.
[1] A resist composition comprising a resin (A1) containing a structural unit represented by formula (I) and a structural unit having an acid labile group, and an acid generator represented by formula (B1).

[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
L ¹ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O— or —CO—.
R ² represents a C 1-10 hydrocarbon group which may have a halogen atom.
R ³ represents an alkyl group having 1 to 10 carbon atoms, a halogen atom or a hydroxyl group.
W represents a hydrocarbon ring having 5 to 18 carbon atoms, and —CH ₂ — contained in the hydrocarbon ring may be replaced with —O— or —CO—.
l represents an integer of 0 to 4.
m represents an integer of 1 to 3.
n represents an integer of 0 to 10. When n is 2 or more, the plurality of R ³ may be the same or different. ]

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. —CH ₂ — contained in the group and the monovalent alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]
[2] The resist composition according to [1], wherein L ¹ is a single bond.
[3] The resist composition according to [1] or [2], wherein W is an adamantane ring.
[4] The resist composition according to any one of [1] to [3], further comprising a resin (A2) having a fluorine atom and not containing a structural unit having an acid labile group.
[5] The resist composition according to [4], wherein the resin (A2) is a resin composed of a structural unit represented by the formula (a4-1).

[In the formula (a4-1),
R ^a41 represents a monovalent hydrocarbon group having 1 to 12 carbon atoms, and —CH ₂ — containing the hydrocarbon group may be replaced with —O— or —CO—.
A ^a41 is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a formula (a-g1).

(In the formula (a-g1), s represents 0 or 1.
A ^a42 and A ^a44 each independently represent an ^optionally substituted aliphatic hydrocarbon group having 1 to 5 carbon atoms.
A ^a43 represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent or a single bond.
X ^a41 and X ^a42 each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 7 or less. )
Represents a group represented by
R ^a42 represents a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, the methylene group of which may be substituted with a carbonyloxy group or an oxycarbonyl group.
However, at least one of A ^a41 and R ^a42 is a group having a fluorine atom. ]
[6] The resist composition according to any one of [1] to [5], further comprising a salt having a lower acidity than the acid generated from the acid generator represented by formula (B1).

  According to the resist composition of the present invention, a resist pattern having a good shape can be produced.

The schematic diagram of the cross-sectional shape of a line pattern is represented. 1A shows a cross section with a top shape close to a rectangle, FIG. 1B shows a cross section with a round top shape, and FIG. 1D shows a cross section with a tail.

  In the present specification, “(meth) acrylate” means “at least one of acrylate and methacrylate”. The notations such as “(meth) acrylic acid” and “(meth) acryloyl” have the same meaning.

<Resist composition>
The resist composition of the present invention contains a resin (A1) and an acid generator (B1).

<Resin (A1)>
The resin (A1) includes a structural unit represented by the formula (I) (hereinafter sometimes referred to as “structural unit (I)”) and a structural unit having an acid labile group. Since the structural unit (I) and the structural unit having an acid labile group are included, a resist pattern having a good shape can be produced.

  <Structural unit represented by formula (I)>

Examples of the halogen atom for R ¹ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Preferred is a fluorine atom.
Examples of the alkyl group for R ¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and n-hexyl group. , Preferably it is a C1-C4 alkyl group, More preferably, it is a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom of R ¹ include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluoro group. A hexyl group, a trichloromethyl group, a tribromomethyl group, a triiodomethyl group, etc. are mentioned.
R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

The divalent saturated hydrocarbon group for L ¹ is a divalent aliphatic saturated hydrocarbon group or a divalent alicyclic saturated hydrocarbon group, preferably a divalent aliphatic saturated hydrocarbon group. Specific examples include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group.
The divalent alicyclic saturated hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

式（Ｌ１−１）中、
Ｘ^x1は、＊−ＣＯ−Ｏ−、＊−Ｏ−ＣＯ−又は−Ｏ−を表し、＊はＬ^x1との結合手を表す。
Ｌ^x1は、炭素数１〜１６の２価の飽和炭化水素基を表す。
Ｌ^x2は、単結合又は炭素数１〜１６の２価の飽和炭化水素基を表す。
ただし、Ｌ^x1、Ｌ^x2及びＸ^x1の合計炭素数は、１８以下である。 Examples of the group in which —CH ₂ — contained in the saturated hydrocarbon group is replaced by —O— or —CO— include a group represented by the formula (L1-1). In the following formula, * represents a bond with -O-.

In formula (L1-1),
X ^x1 represents * —CO—O—, * —O—CO— or —O—, and * represents a bond to L ^x1 .
L ^x1 represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x1 , L ^x2 and X ^x1 is 18 or less.

X ^x1 is preferably * —CO—O— or * —O—CO—, more preferably * —CO—O—.
L ^x1 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, still more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond. Or a methylene group, even more preferably a single bond.

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

L ¹ is preferably a single bond or a group represented by the formula (L1-1), more preferably a single bond or —CH ₂ —CO—O—, and still more preferably a single bond.

The hydrocarbon ring in W may be an aromatic ring or an aliphatic ring, and an aliphatic ring is preferable. Moreover, it may be monocyclic or polycyclic.
As a hydrocarbon ring in W, C6-C18 is preferable and C6-C12 is more preferable.
Examples of the aliphatic ring include a cycloheptane ring, a cyclohexane ring, an adamantane ring, a norbornane ring, and the like, and an adamantane ring is preferable.

Examples of the hydrocarbon group in R ² include aliphatic hydrocarbon groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group. , An alicyclic hydrocarbon group such as a cyclopentyl group and a cyclohexyl group, and an aromatic hydrocarbon group such as a phenyl group and a methylphenyl group, and a group obtained by combining these two or more groups. An aliphatic hydrocarbon group or an aromatic hydrocarbon group is preferable, and a methyl group, an ethyl group, a phenyl group, or a methylphenyl group is more preferable.
Examples of the hydrocarbon group having a halogen atom include a trifluoromethyl group.
Examples of the alkyl group for R ³ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. . Preferably it is a C1-C6 alkyl group, More preferably, it is a C1-C4 alkyl group.
l is preferably 0 or 1, more preferably 0.
m is preferably 1 or 2, and more preferably 1.
n is preferably an integer of 0 to 3, more preferably 0 or 1, and still more preferably 0.

Specific examples of the structural unit (I) are shown below.

［式（Ｉ’）中、Ｒ¹、Ｒ²、Ｒ³、Ｗ、Ｌ¹、ｌ、ｍ及びｎは上記と同じ意味を表す。］ The structural unit (I) is derived from a compound represented by the formula (I ′) (hereinafter sometimes referred to as “compound (I ′)”).

[In the formula (I ′), R ¹ , R ² , R ³ , W, L ¹ , l, m, and n represent the same meaning as described above. ]

  Compound (I ′) can be easily obtained from the market, and can be synthesized, for example, by the methods described in JP-A-2005-220066, JP-A-2006-104173, and JP-A-2007-284381.

  The content of the structural unit (I) contained in the resin (A1) is preferably 1 to 50 mol%, more preferably 1 to 40 mol%, still more preferably 2 with respect to all the structural units of the resin (A1). -30 mol%, particularly preferably 3-20%.

The resin (A1) of the present invention includes a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a1)”). Further, the resin (A) may contain a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”).
The acid labile group as used herein refers to a group having a leaving group, which is removed by contact with an acid and the structural unit is converted into a hydrophilic group (for example, a hydroxy group or a carboxy group). means.
The structural unit (a1) is preferably from 50 to 99 mol%, more preferably from 60 to 99 mol%, still more preferably from 70 to 98 mol%, particularly preferably from 80 to 99 mol%, based on all structural units of the resin (A1). 97%.

［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。］ <Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”).
The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, more preferably a (meth) acrylic monomer having an acid labile group.
The term “acid labile group” as used herein means a group having a leaving group and forming a hydrophilic group (for example, a hydroxy group or a carboxy group) by leaving the leaving group upon contact with an acid. . In resin (A1), group (1) and / or group (2) are preferable.

[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 a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* 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 (A1) 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, norbornyl group, Examples thereof include a methylnorbornyl group and an isobornyl group.
Examples of the group formed by combining the alkyl group of R ^a6 and R ^a7 and the alicyclic hydrocarbon group include an aralkyl group, and 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), for example, 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 ( The monomer represented by any one of a1-1-10) 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, for example. 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.

Examples of the monomer (a1-2) include 1-methylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclopentan-1-yl (meth) acrylate, and 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-isopropylcyclopentane-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 (A1) 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 (A1). It is 10-95 mol% normally with respect to a unit, Preferably it is 15-90 mol%, More preferably, it is 20-85 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 (A1) containing the structural unit (a1-3) contains a sterically bulky structural unit, the resist composition of the present invention containing such a resin (A1) 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 (A1) includes the structural unit (a1-3), the content thereof is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, based on all the structural units of the resin (A1). 20-85 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 (A1) has a structural unit (a1-4), the content rate is preferable with respect to all the structural units of resin (A1), and 10-95 mol% is more preferable, and 15-90 mol% is more preferable. 20 to 85 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 (A1) has the structural unit (a1-5), the content is preferably from 1 to 50 mol%, more preferably from 3 to 45 mol%, based on all the structural units of the resin (A1). 5 to 40 mol% is more preferable.

The structural unit (a) having an acid labile group in the resin (A1) 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 combination of the structural unit (a1-1) and the structural unit (a1-2), a structural unit (a1-0), and a structural unit (a1- 1) and structural unit (a1-5 More preferably a combination of a combination of structural units (a1-1) and the structural 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 a structural unit (a2-0) having a phenolic hydroxy group. Moreover, when using ArF excimer laser (193 nm) etc., it is preferable to use the structural unit (a2-1) which has an alcoholic hydroxy group as a structural unit (a2). As a structural unit (a2), 1 type may be included independently and 2 or more types may be included.

中でも、式（ａ２−０−１）又は式（ａ２−０−２）で表されるものがより好ましい。
構造単位（ａ２−０）を誘導するモノマーとしては、例えば、特開２０１０−２０４６３４号公報に記載されているモノマーが挙げられる。 Examples of the structural unit (a2-0) having a phenolic hydroxy group include the following structures.

Especially, what is represented by a formula (a2-0-1) or a formula (a2-0-2) is more preferable.
Examples of the monomer that derives the structural unit (a2-0) include monomers described in JP 2010-204634 A.

  The resin (A1) 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 the resin (A1) has the structural unit (a2-0), the content is preferably from 5 to 95 mol%, more preferably from 10 to 80 mol%, based on all the structural units of the resin (A1). 15-80 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 structures.

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 (A1) contains a structural unit (a2-1) structural unit, the content rate is 1-45 mol% normally with respect to all the structural units of resin (A1), Preferably it is 1-40 mol. %, More preferably 1 to 35 mol%, and still more preferably 2 to 20 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, the structural unit (a3) including a γ-butyrolactone ring or a bridged ring including a γ-butyrolactone ring structure may contain two or more kinds. 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 (A1) contains the structural unit (a3), the content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A1). More preferably, it is 10-60 mol%.

<Other structural units (t)>
As the structural unit (t), in addition to the structural unit (a2) and the structural unit (a3), a structural unit 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)”).

［式（ａ４−０）中、
Ｒ^５は、水素原子又はメチル基を表す。
Ｌ^２は、炭素数１〜４の脂肪族飽和炭化水素基を表す。
Ｌ^３は、炭素数１〜８のペルフルオロアルカンジイル基を表す。
Ｒ^６は、水素原子又はフッ素原子を表す。］ As the structural unit (a4), a structural unit represented by formula (a4-0) can be given.

[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ² represents an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a C 1-8 perfluoroalkanediyl group.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

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

L ² is preferably a methylene group or an ethylene group, and more preferably a methylene group.
L ³ is preferably a C 1-6 perfluoroalkanediyl group, and more preferably a C ^1-3 C perfluoroalkanediyl group.

Examples of the structural unit (a4-0) include the following.

In the above structural unit, a structural unit in which a methyl group corresponding to R ³ is replaced by a hydrogen atom can also be given as a specific example of the structural unit (a4-0).

［式（ａ４−１）中、
Ｒ^a41は、水素原子又はメチル基を表す。
Ａ^a41は、置換基を有していてもよい炭素数１〜６のアルカンジイル基又は式（ａ−ｇ１）

〔式（ａ−ｇ１）中、
ｓは０又は１を表す。
Ａ^a42及びＡ^a44は、それぞれ独立に、置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基を表す。
Ａ^a43は、置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基又は単結合を表す。
Ｘ^a41及びＸ^a42は、それぞれ独立に、−Ｏ−、−ＣＯ−、−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−を表す。
ただし、Ａ^a42、Ａ^a43、Ａ^a44、Ｘ^a41及びＸ^a42の炭素数の合計は６以下である。〕
で表される基を表す。
Ｒ^a42は、置換基を有していてもよい炭素数１〜２０の炭化水素基を表す。
ただし、Ａ^a41及びＲ^a４２のうち少なくとも一方は、ハロゲン原子を有する基である。］ As the structural unit (a4), a structural unit represented by formula (a4-1) can be given.

[In the formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
A ^a41 is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a formula (a-g1).

[In the formula (a-g1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent an ^optionally substituted aliphatic hydrocarbon group having 1 to 5 carbon atoms.
A ^a43 represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent or a single bond.
X ^a41 and X ^a42 each independently represent —O—, —CO—, ^—CO —O— or —O—CO—.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 6 or less. ]
Represents a group represented by
R ^a42 represents an ^optionally substituted hydrocarbon group having 1 to 20 carbon atoms.
However, at least one of A ^a41 and R ^a42 is a group having a halogen atom. ]

As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned, Preferably it is a fluorine atom.
The aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, but is preferably an aliphatic saturated hydrocarbon group. As the aliphatic saturated hydrocarbon group, an alkyl group (the alkyl group may be linear or branched) and an alicyclic hydrocarbon group, and an alkyl group and an alicyclic hydrocarbon group are combined. Examples thereof include aliphatic hydrocarbon groups that are formed.

芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ビフェニリル基、フェナントリル基及びフルオレニル基等が挙げられる。 ^Examples of the hydrocarbon group for R ^a42 include chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these. Examples of chain aliphatic hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, hexadecyl, pentadecyl, hexyldecyl , Heptadecyl group and octadecyl group. Cyclic aliphatic hydrocarbon groups include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and other cycloalkyl groups; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* is a bond) And a polycyclic alicyclic hydrocarbon group of a polycyclic alicyclic hydrocarbon group such as.

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

［式（ａ−ｇ３）中、
Ｘ^a43は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^a45は、少なくとも１つのハロゲン原子を有する炭素数３〜１７の脂肪族炭化水素基を表す。］
Ｒ^a4２が、式（ａ−ｇ３）で表される基を有する脂肪族炭化水素基である場合、式（ａ−ｇ３）で表される基に含まれる炭素数を含めて、脂肪族炭化水素基の総炭素数は、１５以下が好ましく、１２以下がより好ましい。式（ａ−ｇ３）で表される基を置換基として有する場合、その数は１個が好ましい。 The hydrocarbon group for R ^a42 is preferably a chain or cyclic aliphatic hydrocarbon group or a group formed by a combination thereof, and may have a carbon-carbon unsaturated bond. More preferred are formula and cyclic aliphatic saturated hydrocarbon groups and groups formed by combining them.
As the aliphatic hydrocarbon group, an alkyl group and an alicyclic hydrocarbon group are preferable.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group and 2 -An ethylhexyl group is mentioned.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a methyl group. Examples thereof include cycloalkyl groups such as cyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group, and 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 and isobornyl group.
R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and / or an aliphatic hydrocarbon group having a group represented by the formula (a-g3). .

[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents a C ^3-17 aliphatic hydrocarbon group having at least one halogen atom. ]
When R ^a42 is an aliphatic hydrocarbon group having a group represented by the formula (a-g3), including the number of carbons contained in the group represented by the formula (a-g3), the aliphatic hydrocarbon The total carbon number of the group is preferably 15 or less, more preferably 12 or less. When it has a group represented by the formula (a-g3) as a substituent, the number is preferably 1.

［式（ａ−ｇ２）中、
Ａ^a46は、ハロゲン原子を有していてもよい炭素数３〜１７の脂肪族炭化水素基を表す。
Ｘ^a44は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数３〜１７の脂肪族炭化水素基を表す。
ただし、Ａ^a46、Ａ^a47及びＸ^a44の炭素数の合計は１８以下であり、Ａ^a46及びＡ^a47のうち、少なくとも一方は、少なくとも１つのハロゲン原子を有する。］ The aliphatic hydrocarbon having a group represented by the formula (a-g3) is more preferably a group represented by the formula (a-g2).

[In the formula (a-g2),
A ^a46 represents an aliphatic hydrocarbon group having 3 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents a carbonyloxy group or an oxycarbonyl group.
A ^a47 represents an aliphatic hydrocarbon group having 3 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47, and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom. ]

Preferred R ^a42 , an aliphatic hydrocarbon group having a substituent selected from the group consisting of a halogen atom and a group represented by formula (a-g3) (a group represented by formula (a-g2)) Detailed description.

When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and still more preferably a carbon number. It is a 1-6 perfluoroalkyl group, Most preferably, it is a C1-C3 perfluoroalkyl group. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group.

1-6 are preferable and, as for carbon number of the aliphatic hydrocarbon group of ^Aa46 , 1-3 are more preferable.
4-15 are preferable, as for carbon number of the aliphatic hydrocarbon group of A ^<a47> , 5-12 are more preferable, and A ^<a47> has a more preferable cyclohexyl group or an adamantyl group.

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

^As the alkanediyl group of ^Aa41 , a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group Linear alkanediyl group such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, Examples include branched alkanediyl groups such as 2-methylbutane-1,4-diyl group.
^Examples of the substituent in the alkanediyl group of A ^a41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and still more preferably an ethylene group.

In the group represented by the formula (a-g1) of A ^a41 (hereinafter sometimes referred to as “group (a-g1)”), A ^a44 is ^bonded to —O—CO—R ^a42 .
As the aliphatic hydrocarbon group for A ^a42 , A ^a43 and A ^{a44 in} the group (a-g1), a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane- Examples include 1,4-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group and the like. Examples of these substituents include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.

^Examples of the group ( ^{ag1) in} which X ^a42 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group include the following groups. In the following examples, among the two bonds represented by *, * on the right side is a bond with —O—CO—R ^a42 .

［式（ａ４−２）中、
Ｒ^ｆ1は、水素原子又はメチル基を表す。
Ａ^ｆ1は、炭素数１〜６のアルカンジイル基を表す。
Ｒ^ｆ2は、フッ素原子を有する炭素数１〜１０の炭化水素基を表す。］ As the structural unit represented by the formula (a4-1), a structural unit represented by the formula (a4-2) or the formula (a4-3) is preferable.

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

As the alkanediyl group of A ^f1 , a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group , A straight-chain alkanediyl group such as hexane-1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 -Branched alkanediyl groups such as a diyl group, 1-methylbutane-1,4-diyl group, 2-methylbutane-1,4-diyl group.

The hydrocarbon group of R ^f2 includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and the aliphatic hydrocarbon group includes a chain, a cyclic group, and a group formed by a combination thereof. As the aliphatic hydrocarbon group, an alkyl group and an alicyclic hydrocarbon group are preferable.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group and 2 -An ethylhexyl group is mentioned.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a methyl group. Examples thereof include cycloalkyl groups such as cyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group, and 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 and isobornyl group.

Examples of the hydrocarbon group having a fluorine atom for R ^f2 include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
Specifically, as the alkyl group having a fluorine atom, a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2 , 2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2, 2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoro (Ropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5- Decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2, 2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentyl Examples thereof include fluorinated alkyl groups such as a methyl group and a perfluorohexyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom include fluorinated cycloalkyl groups such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

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

［式（ａ４−３）中、
Ｒ^ｆ11は、水素原子又はメチル基を表す。
Ａ^ｆ11は、炭素数１〜６のアルカンジイル基を表す。
Ａ^ｆ13は、フッ素原子を有していてもよい炭素数１〜１８の脂肪族炭化水素基を表す。
Ｘ^ｆ12は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^ｆ14は、フッ素原子を有していてもよい炭素数１〜１７の脂肪族炭化水素基を表す。 ただし、Ａ^ｆ13及びＡ^ｆ14の少なくとも１つは、フッ素原子を有する脂肪族炭化水素基を表す。］

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

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

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

As the aliphatic hydrocarbon group for A ^f14 , one of a chain type and a cyclic type, and an aliphatic hydrocarbon group formed by combining them are included. The aliphatic hydrocarbon may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom for A ^f14 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom.
Examples of the chain aliphatic hydrocarbon group which may have a fluorine atom include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, 1,1 , 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, A heptyl group, a perfluoro heptyl group, an octyl group, a perfluorooctyl group, etc. are mentioned.
Etc.
The cyclic aliphatic hydrocarbon group which may have a fluorine atom may be monocyclic or polycyclic. Examples of the group containing a monocyclic aliphatic hydrocarbon group include a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, and a perfluorocyclohexyl group. Examples of the group containing a polycyclic aliphatic hydrocarbon group include an adamantyl group, an adamantylmethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, and a perfluoroadamantylmethyl group.

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

Examples of the monomer for deriving the structural unit represented by formula (a4-2) include monomers represented by formula (a4-1-1) to formula (a4-1-22), respectively.

Examples of the monomer for deriving the structural unit represented by formula (a4-3) include monomers represented by formula (a4-1′-1) to formula (a4-1′-22), respectively.

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

[In the formula (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 represents — (CH ₂ ) _j1 —, — (CH ₂ ) _j2 —O— (CH ₂ ) _j3 — or — (CH ₂ ) _j4 —CO—O— (CH ₂ ) _j5 —.
j1 to j5 each independently represents an integer of 1 to 6.
R ^f22 represents a C 1-10 hydrocarbon group having a fluorine atom. ]

^Examples of the hydrocarbon group having a fluorine atom of R ^f22 include the same hydrocarbon groups as R ^f2 in formula (a4-2). R ^f22 is preferably a ^C 1-10 alkyl group having a fluorine atom or a C 1-10 alicyclic hydrocarbon group having a fluorine atom, more preferably a C 1-10 alkyl group having a fluorine atom. Preferably, the C1-C6 alkyl group which has a fluorine atom is further more preferable.

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

Examples of the monomer for deriving the structural unit represented by the formula (a4-4) include the following monomers.

  When the resin (A) has a structural unit (a4), the content is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, based on all structural units of the resin (A). More preferably, it is 10 mol%.

構造単位（ａ５）としては、以下の構造単位が挙げられる。 <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 following structural units.

  The resin (A1) may have a structural unit other than the above-described structural units, and examples of the structural unit include structural units well known in the art.

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

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

Each structural unit constituting the resin (A1) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do. The content rate of each structural unit which resin (A1) has can be adjusted with the usage-amount of the monomer used for superposition | polymerization.
The weight average molecular weight of the resin (A1) is preferably 2,000 or more (more preferably 2,500 or more, more preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, and further preferably 15,000 or less).

<Resin (A2)>
The resin (A2) does not include a structural unit having a fluorine atom and having an acid labile group.
As such a resin, a resin including the structural unit (a4) (however, the structural unit (a1) is not included) is preferable, and a resin including the structural unit (a4-0) is more preferable. In the resin (A2), the content of the structural unit (a4) is preferably 40 mol% or more, more preferably 45 mol% or more, and still more preferably 50 mol% or more with respect to all the structural units of the resin (A2). .
Examples of the structural unit that the resin (A2) may further include a structural unit derived from the structural unit (a2), the structural unit (a3), the structural unit (a5), and other known monomers.
The weight average molecular weight of the resin (A2) is preferably 8,000 or more (more preferably 10,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weight of the resin (A2) is the same as that for the resin (A1).
When the resist composition contains the resin (A2), the content thereof is preferably 1 to 60 parts by mass, more preferably 3 to 50 parts by mass with respect to 100 parts by mass of the resin (A1). Preferably it is 5-40 mass parts, Most preferably, it is 7-30 mass parts.

  As for the total content rate of resin (A1) and resin (A2), 80 to 99 mass% is preferable with respect to solid content of a resist composition. In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent (E) described later from the total amount of the resist composition. The solid content of the resist composition and the resin content relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

<Acid generator (B1)>
The acid generator (B1) is a salt represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”).

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１〜２４の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の１価の脂環式炭化水素基を表し、該アルキル基及び該１価の脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−に置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］

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

Examples of the perfluoroalkyl group of Q ¹ and Q ² include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, and perfluoro group. A hexyl group etc. are mentioned.
Q ¹ and Q ² are each independently preferably a fluorine atom or a trifluoromethyl group, and both Q ¹ and Q ² are more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and these It may be a group formed by combining two or more of the groups.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 , 7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group , Tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group Alkanediyl group;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group 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 group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include any of formulas (b1-1) to (b1-3) The group represented by these is mentioned. In the formulas (b1-1) to (b1-3) and the following specific examples, * represents a bond with -Y.

式（ｂ１−１）中、
Ｌ^b2は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b3は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ただし、Ｌ^b2とＬ^b3との炭素数合計は、２２以下である。
式（ｂ１−２）中、
Ｌ^b４は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b５は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ただし、Ｌ^b4とＬ^b5との炭素数合計は、２２以下である。
式（ｂ１−３）中、
Ｌ^b6は、単結合又は炭素数１〜２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
Ｌ^b7は、単結合又は炭素数１〜２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ただし、Ｌ^b6とＬ^b7との炭素数合計は、２３以下である。

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

In formulas (b1-1) to (b1-3), when the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group, the number of carbons before the replacement is represented by the saturated hydrocarbon group. The number of carbons.
Examples of the divalent saturated hydrocarbon group include those similar to the divalent saturated hydrocarbon group of L ^b1 .

L ^b2 is preferably a single bond.
L ^b3 is preferably an alkanediyl group having 1 to 4 carbon atoms.
L ^b4 is preferably a C 1-8 divalent saturated hydrocarbon group, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group The methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.

  Among these, a group represented by the formula (b1-1) or the formula (b1-3) is preferable.

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

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

L ^b8 is preferably an alkanediyl group having 1 to 4 carbon atoms.
L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b16 preferably represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b17 preferably represents a ^C 1-6 divalent saturated hydrocarbon group.
L ^b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms,

式（ｂ１−９）中、
Ｌ^b19は、単結合又は炭素数１〜２３の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b20は、単結合又は炭素数１〜２３の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b19及びＬ^b20の合計炭素数は２３以下である。
式（ｂ１−１０）中、
Ｌ^b21は、単結合又は炭素数１〜２１の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b22は、単結合又は炭素数１〜２１の２価の飽和炭化水素基を表す。
Ｌ^b23は、単結合又は炭素数１〜２１の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b21、Ｌ^b22及びＬ^b23の合計炭素数は２１以下である。
式（ｂ１−１１）中、
Ｌ^b24は、単結合又は炭素数１〜２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b25は、炭素数１〜２１の２価の飽和炭化水素基を表す。
Ｌ^b26は、単結合又は炭素数１〜２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b24、Ｌ^b25及びＬ^b26の合計炭素数は２１以下である。 Examples of formula (b1-3) include groups represented by formula (b1-9) to formula (b1-11), respectively.

In formula (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. May be. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b19 and L ^b20 is 23 or less.
In formula (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. May be. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b21 , L ^b22 and L ^b23 is 21 or less.
In formula (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group, or an acyloxy group. May be. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
However, L ^b24, the total number of carbon atoms of L ^b25 and L ^b26 is 21 or less.

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

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

Of the groups represented by formula (b1-1), examples of the group represented by formula (b1-4) include the following.

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

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

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

Of the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-8) include the following.

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

Of the groups represented by formula (b1-3), examples of the group represented by formula (b1-9) include the following.

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

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

Examples of the alkyl group represented by Y 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, heptyl. Group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group and other alkyl groups, and preferably an alkyl group having 1 to 6 carbon atoms.
Examples of the monovalent alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y11).
Examples of the group in which —CH ₂ — contained in the monovalent alicyclic hydrocarbon group represented by Y is replaced by —O—, —SO ₂ — or —CO— include formulas (Y12) to (Y26). The group represented by these is mentioned.

  Especially, it is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

Examples of the substituent for the alkyl group represented by Y include a halogen atom, a hydroxy group, a monovalent n-alicyclic hydrocarbon group having 3 to 16 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. , Glycidyloxy group or — (CH ₂ ) _en —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, monovalent alicyclic hydrocarbon having 3 to 16 carbon atoms) Represents a group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and ja represents an integer of 0 to 4).
Examples of the substituent for the monovalent alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and 3 carbon atoms. -16 monovalent alicyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 monovalent aromatic hydrocarbon group, C7-C21 aralkyl group, C2-C2 4 acyl group, glycidyloxy group or — (CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, monovalent fat having 3 to 16 carbon atoms) Represents a cyclic hydrocarbon group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and ja represents an integer of 0 to 4).

Examples of the hydroxy group-containing alkyl 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 monovalent aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group, mesityl group. Groups, biphenyl groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Examples of Y include the following.

When Y is an alkyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated hydrocarbon at the bonding position with Y The group —CH ₂ — is preferably replaced by —O— or —CO—. In this case, —CH ₂ — contained in the alkyl group of Y is not replaced with —O— or —CO—. The same applies when a hydrogen atom contained in the alkyl group of Y and / or the divalent linear or branched saturated hydrocarbon group of L ^b1 is substituted with a substituent.

  Y is preferably a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably an adamantyl group which may have a substituent. The methylene group constituting the group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group. Y is particularly preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

Examples of the sulfonate anion in the salt represented by the formula (B1) include anions represented by the formulas (IA-1) to (IA-33) [hereinafter referred to as “anions (I -A-1) "or the like. Are preferred, formula (IA-1) to formula (IA-4), formula (IA-9), formula (IA-10), formula (IA-24) to formula An anion represented by any of (IA-33) is more preferred. R ^{i2 to} R ⁱ⁷ are, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R ⁱ⁸ is, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. A group to be formed, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L ⁴ is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Specific examples of the sulfonate anion in the salt represented by the formula (B1) include the anions described in JP 2010-204646 A.

Among these, examples of the sulfonate anion in the salt represented by the preferable formula (B1) include anions represented by the formulas (B1a-1) to (B1a-15), respectively.

Among them, A ^- as the formula (B1a-1) to Formula (B1a-3) and formula (B1a-7) anion represented by any one of the - formula (B1a-15) are preferred.

Examples of the organic cation of Z ⁺ include an organic onium cation such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation, and preferably an organic sulfonium cation or an organic iodonium cation. More preferably an arylsulfonium cation.
Z ⁺ in formula (B1) is preferably a cation represented by any one of formula (b2-1) to formula (b2-4) [hereinafter referred to as “cation (b2-1)” or the like depending on the formula number, etc. There is a case. ]

In formula (b2-1) to formula (b2-4),
R ^{b4 to} R ^b6 are each independently a monovalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms, or a monovalent group having 6 to 36 carbon atoms. The hydrogen atom contained in the monovalent aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or a monovalent alicyclic carbon group having 3 to 12 carbon atoms. It may be substituted with a hydrogen group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the monovalent alicyclic hydrocarbon group is a halogen atom or a carbon number 1 to 18 Which may be substituted with a monovalent aliphatic hydrocarbon group, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group, the hydrogen atom contained in the monovalent aromatic hydrocarbon group is a halogen atom, hydroxy Group or an alkoxy group having 1 to 12 carbon atoms may be substituted.
R ^b4 and R ^b5 may form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be replaced with —O—, —SO— or —CO—. .

R ^b7 and R ^b8 each independently represent a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.
When m2 is 2 or more, the plurality of R ^b7 may be the same or different, and when n2 is 2 or more, the plurality of R ^b8 may be the same or different.

R ^b9 and R ^b10 each independently represent a monovalent aliphatic hydrocarbon group having 1 to 36 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be replaced with —O—, —SO— or —CO—. .
R ^b11 is a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 36 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms, or a monovalent aromatic carbon group having 6 to 18 carbon atoms. Represents a hydrogen group.
R ^b12 represents a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. And a hydrogen atom contained in the monovalent aliphatic hydrocarbon may be substituted with a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and is contained in the monovalent aromatic hydrocarbon group The hydrogen atom to be substituted may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms.
R ^b11 and R ^b12 may together form a ring containing —CH—CO— to which they are bonded, and —CH ₂ — contained in the ring is —O—, —SO—. Alternatively, it may be replaced by -CO-.

R ^{b13 to} R ^b18 each independently represent a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b11 represents -S- or -O-.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, multiple R ^b13 are the same or different, when p2 is 2 or more, multiple R ^b14 are the same or different, and when q2 is 2 or more, multiple R ^b15 are the same or different , When r2 is 2 or more, a plurality of R ^b16 are the same or different, when s2 is 2 or more, a plurality of R ^b17 are the same or different, and when t2 is 2 or more, a plurality of R ^b18 are the same or different Different.

特に、Ｒ^b9〜Ｒ^b12の１価の脂環式炭化水素基は、好ましくは炭素数３〜１８、より好ましくは炭素数４〜１２である。 Monovalent aliphatic hydrocarbon groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl and 2 -The alkyl group of an ethylhexyl group is mentioned. In particular, the monovalent aliphatic hydrocarbon group of R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
The monovalent alicyclic hydrocarbon group may be monocyclic or polycyclic, and the monocyclic monovalent alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, Examples thereof include cycloalkyl groups such as a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group. Examples of the polycyclic monovalent alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups.

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

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

Examples of the monovalent aromatic hydrocarbon group include phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group, p- Examples thereof include aryl groups such as an adamantylphenyl group, a biphenylyl group, a naphthyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.
When the monovalent aromatic hydrocarbon group includes a monovalent aliphatic hydrocarbon group or a monovalent alicyclic hydrocarbon group, the monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms. And a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms is preferred.
Examples of the monovalent aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group.
Examples of the monovalent aliphatic hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. .

Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

The ring that R ^b4 and R ^b5 may form together with the sulfur atom to which they are bonded is a monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated ring. There may be. Examples of the ring include a ring having 3 to 18 carbon atoms, and a ring having 4 to 18 carbon atoms is preferable. Moreover, the ring containing a sulfur atom includes a 3-membered ring to a 12-membered ring, and preferably a 3-membered ring to a 7-membered ring. For example, the following rings are mentioned.

The ring formed by R ^b9 and R ^b10 together with the sulfur atom to which they are bonded may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Good. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring.
The ring formed by ^combining R ^b11 and R ^b12 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Among the cation (b2-1) to cation (b2-4), the cation (b2-1) is preferable, more preferably a cation represented by the formula (b2-1-1) (hereinafter referred to as “cation ( more preferably triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0), diphenyltolylsulfonium cation (formula In (b2-1-1), v2 = w2 = 0, x2 = 1, and R ^b21 is a methyl group.) Or a tolylsulfonium cation (in the formula (b2-1-1), v2 = w2 = x2 = 1, and R ^b19 , R ^b20 and R ^b21 are all methyl groups.).

式（ｂ２−１−１）中、
Ｒ^b19、Ｒ^b20及びＲ^b21は、それぞれ独立に、ハロゲン原子、ヒドロキシ基、炭素数１〜１８の１価の脂肪族炭化水素基、炭素数１〜１２のアルコキシ基又は炭素数３〜１８の１価の脂環式炭化水素基を表す。また、Ｒ^b19〜Ｒ^b21から選ばれる２つが一緒になって硫黄原子を含む環を形成してもよい。
ｖ２、ｗ２及びｘ２は、それぞれ独立に０〜５の整数を表す。
ｖ２が２以上のとき、複数のＲ^b19は同一又は相異なり、ｗ２が２以上のとき、複数のＲ^b20は同一又は相異なり、ｘ２が２以上のとき、複数のＲ^b21は同一又は相異なる。

In formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom, a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or a carbon atom having 3 to 18 carbon atoms. Represents a monovalent alicyclic hydrocarbon group. It is also possible that two selected from R ^b19 to R ^b21 together form a ring containing a sulfur atom.
v2, w2 and x2 each independently represent an integer of 0 to 5.
When v2 is 2 or more, the plurality of R ^b19 are the same or different, when w2 is 2 or more, the plurality of R ^b20 are the same or different, and when x2 is 2 or more, the plurality of R ^b21 are the same or different. .

The ring or two of R ^b19 to R ^b21 is that together form a monocyclic, polycyclic, aromatic, may be any ring nonaromatic, sulfur atom 1 As long as it contains the above, it may contain one or more sulfur atoms and / or one or more oxygen atoms.
The monovalent aliphatic hydrocarbon group represented by R ^{b19 to} R ^b21 preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 4 to 18 carbon atoms.
Among them, R ^{b19 to} R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. or represented, it is preferable two selected from R ^b19 to R ^b21 is that together form a ring containing an oxygen atom and a sulfur atom.
v2, w2 and x2 are each independently preferably 0 or 1.

Among them, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a carbon number. or represents from 1 to 12 alkoxy groups, it is preferable two selected from R ^b19 to R ^b21 is that together form a ring containing an oxygen atom and a sulfur atom.
v2, w2 and x2 are each independently preferably 0 or 1.

  Specific examples of the cation (b2-1-1) include cations described in JP 2010-204646 A.

  The acid generator (B1) is a combination of the above-described sulfonate anion and the above-mentioned organic cation, and these can be arbitrarily combined. The acid generator (B1) is preferably an anion and a cation represented by any one of formulas (B1a-1) to (B1a-3) and (B1a-7) to (B1a-15) ( a combination with b2-1-1) or a cation (b2-3).

  Preferred examples of the acid generator (B1) include those represented by formulas (B1-1) to (B1-28). Among them, the formula (B1-1) and the formula (B) containing an arylsulfonium cation are preferable. B1-2), formula (B1-3), formula (B1-5), formula (B1-6), formula (B1-7), formula (B1-11), formula (B1-12), formula (B1) -13), formula (B1-14), formula (B1-13), formula (B1-20), formula (B1-21), formula (B1-23), formula (B1-24), formula (B1- 25) or the formula (B1-26), respectively, is particularly preferable.

The resist composition of the present invention may contain one kind of acid generator (B1) alone, or may contain plural kinds. Moreover, you may contain acid generators other than an acid generator (B1).
The content of the acid generator (B1) is preferably 30% by mass or more and 100% by mass or less, more preferably 50% by mass or more and 100% by mass or less, with respect to the total amount of the acid generator. More preferably only B1).
The content of the acid generator is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 30 parts by mass or less (more preferably 25 parts by mass or less) with respect to 100 parts by mass of the resin (A). It is.

<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.

<Basic compound (C)>
Examples of the basic compound (C) include weak acid salts having a lower acidity than the basic nitrogen-containing organic compound or 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.

Examples of the weak acid salt having weaker acidity than the acid generator (B) include a salt represented by the following formula, a weak acid inner salt represented by the formula (D), and JP 2012-229206 A, JP Examples include salts described in JP 2012-6908 A, JP 2012-72109 A, JP 2011-39502 A, and JP 2011-191745 A.

［式（Ｄ）中、
Ｒ^Ｄ１及びＲ^Ｄ２は、それぞれ独立に、炭素数１〜１２の１価の炭化水素基、炭素数１〜６のアルコキシ基、炭素数２〜７のアシル基、炭素数２〜７のアシルオキシ基、炭素数２〜７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ’及びｎ’は、それぞれ独立に、０〜４の整数を表し、ｍ’が２以上の場合、複数のＲ^Ｄ１は同一又は相異なり、ｎ’が２以上の場合、複数のＲ^Ｄ２は同一又は相異なる。］ <Weak acid inner salt (D)>
The weak acid inner salt (D) is a compound represented by the formula (D).

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

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

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

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

Examples of the compound (D) include the following compounds.

  Compound (D) can be produced by the method described in “Tetrahedron Vol. 45, No. 19, p6281-6296”. Moreover, the compound (D) can use the compound marketed.

  The content of the basic compound (C) is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass, and particularly preferably 0.01 to 5% by mass in the solid content of the resist composition. 1% by mass.

<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.

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A) and an acid generator of the present invention, and a resin other than the resin (A) used as necessary, a solvent (D), a basic compound (C) and other It can be prepared by mixing component (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature from 10-40 degreeC according to the kind etc. of resin, the solubility with respect to solvent (D), such as 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>
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;
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

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

By drying the composition after coating, the solvent is removed and a composition layer is formed. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called 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 includes a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, particularly an electron. It is suitable as a resist composition for line (EB) exposure or a resist composition for EUV exposure, and is 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 is a value determined by gel permeation chromatography under the following conditions.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

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

式（Ｂ１−５−ａ）で表される塩５０．４９部及びクロロホルム２５２．４４部を反応器に仕込み、２３℃で３０分間攪拌し、式（Ｂ１−５−ｂ）で表される化合物１６．２７部を滴下し、２３℃で１時間攪拌することにより、式（Ｂ１−５−ｃ）で表される塩を含む溶液を得た。得られた式（Ｂ１−５−ｃ）で表される塩を含む溶液に、式（Ｂ１−５−ｄ）で表される塩４８．８０部及びイオン交換水８４．１５部を添加し、２３℃で１２時間攪拌した。得られた反応液が２層に分離していたので、クロロホルム層を分液して取り出し、さらに、該クロロホルム層にイオン交換水８４．１５部を添加し、水洗した。この操作を５回繰り返した。得られたクロロホルム層に、活性炭３．８８部を添加攪拌した後、ろ過した。回収されたろ液を濃縮し、得られた残渣に、アセトニトリル１２５．８７部を添加攪拌し、濃縮した。得られた残渣に、アセトニトリル２０．６２部及びｔｅｒｔ−ブチルメチルエーテル３０９．３０部を加えて２３℃で３０分間攪拌し、上澄み液を除去し、濃縮した。得られた残渣に、ｎ−ヘプタン２００部を添加、２３℃で３０分間攪拌し、ろ過することにより、式（Ｂ１−５）で表される塩６１．５４部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３７５．２
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３３９．１ Synthesis Example 1: Synthesis of salt represented by formula (B1-5)

A compound represented by the formula (B1-5-b) was prepared by charging 50.49 parts of the salt represented by the formula (B1-5-a) and 252.44 parts of chloroform with stirring at 23 ° C for 30 minutes. 16.27 parts was dripped, and the solution containing the salt represented by a formula (B1-5-c) was obtained by stirring at 23 degreeC for 1 hour. To the obtained solution containing the salt represented by the formula (B1-5-c), 48.80 parts of the salt represented by the formula (B1-5-d) and 84.15 parts of ion-exchanged water are added, The mixture was stirred at 23 ° C. for 12 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and 84.15 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. To the obtained chloroform layer, 3.88 parts of activated carbon was added and stirred, followed by filtration. The collected filtrate was concentrated, and 125.87 parts of acetonitrile was added to the resulting residue, and the mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated. To the obtained residue, 200 parts of n-heptane was added, stirred at 23 ° C. for 30 minutes, and filtered to obtain 61.54 parts of the salt represented by the formula (B1-5).
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (−) Spectrum): M ^- 339.1

Synthesis Example 2 [Synthesis of salt represented by formula (B1-21)]

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

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

20.00 parts of a salt represented by the formula (B1-21-c), 2.84 parts of a compound represented by the formula (B1-21-d) and 250 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. . After adding 0.21 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for further 1 hour. After concentrating the obtained reaction solution, 200 parts of chloroform and 50 parts of ion-exchanged water were added to the obtained residue and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After concentrating the obtained organic layer, the residue obtained was dissolved in 53.51 parts of acetonitrile, concentrated, 113.05 parts of tert-butyl methyl ether was added and stirred, and then filtered. 10.47 parts of the salt represented by the formula (B1-21) were obtained.

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (−) Spectrum): M ^- 339.1

Synthesis Example 3 [Synthesis of Salt Represented by Formula (B1-22)]

  11.26 parts of a salt represented by the formula (B1-22-a), 10.00 parts of a compound represented by the formula (B1-22-b), 50 parts of chloroform and 25 parts of ion-exchanged water were charged at 23 ° C. For 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the resulting residue, the mixture was stirred at 23 ° C. for 30 minutes, and then filtered to obtain the salt 11 represented by the formula (B1-22-c). .75 parts were obtained.

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

11.71 parts of a salt represented by the formula (B1-22-c), 1.70 parts of a compound represented by the formula (B1-22-d) and 46.84 parts of monochlorobenzene were charged, and the mixture was charged at 23 ° C. for 30 minutes. Stir. After adding 0.12 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added to the obtained residue and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 12.50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 8 times. After concentration of the obtained organic layer, 50 parts of tert-butyl methyl ether was added to the obtained residue, stirred, and then filtered to obtain 6.84 parts of the salt represented by the formula (B1-22). Got.

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 323.0

以下、これらのモノマーを式番号に応じて「モノマー（ａ１−１−３）」等という。 Resin Synthesis The compounds (monomers) used in the resin synthesis are shown below.

Hereinafter, these monomers are referred to as “monomer (a1-1-3)” or the like according to the formula number.

Synthesis Example 4 [Synthesis of Resin A1-1]
As the monomer, monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-3), monomer (I-1) and monomer (a3-4-2) were used, The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (I-1): monomer (a3-4-2)] is 45:14: The mixture was mixed at 3: 5: 33, and 1.5 mass times the total monomer amount of propylene glycol monomethyl ether acetate was added to obtain a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A1-1 (copolymer) having a molecular weight of 7.2 × 10 ³ was obtained in a yield of 63%. This resin A1-1 has the following structural units.

Synthesis Example 5 [Synthesis of Resin A1-2]
As the monomer, monomer (a1-1-3), monomer (a1-2-9), monomer (I-1) and monomer (a3-4-2) were used, and the molar ratio [monomer (a1-1-3) ): Monomer (a1-2-9): monomer (I-1): monomer (a3-4-2)] is mixed at 45: 14: 8: 33, and the total monomer amount is 1.5 mass. Doubled propylene glycol monomethyl ether acetate was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A1-2 (copolymer) having a molecular weight of 7.0 × 10 ³ was obtained in a yield of 60%. This resin A1-2 has the following structural units.

Synthesis Example 6 [Synthesis of Resin A1-3]
As the monomer, the monomer (a1-0-7) monomer (I-3) and the monomer (a3-2-1) were used, and the molar ratio [monomer (a1-0-7): monomer (I-3): monomer (A3-2-1)] is 40:20:40, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount is added to obtain a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total amount of monomers, and these were added at 70 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A1-3 (copolymer) having a molecular weight of 9.4 × 10 ³ was obtained in a yield of 65%. This resin A1-3 has the following structural units.

Synthesis Example 7 [Synthesis of Resin A2-1]
Monomer (a4-1-7) was used as a monomer, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. Azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the solution in an amount of 0.7 mol% and 2.1 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered.
The resin thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the resin was filtered twice to perform the reprecipitation operation twice. 8 × 10 ⁴ resin A2-1 was obtained with a yield of 77%. This resin A2-1 has the following structural units.

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

<Resin>
A1-1, A1-2, A1-3, A2-1: Resin A1-1, Resin A1-2, Resin A1-3, Resin A2-1
<Acid generator>
<Acid generator>
B1-5: salt represented by formula (B1-5) B1-21: salt represented by formula (B1-21) B1-22: salt represented by formula (B1-22) BX: triphenylsulfonium Hexafluoroantimonate

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

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

Examples 1 to 5 and Comparative Example 1
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a thickness of 78 nm. An organic antireflection film was formed. Subsequently, the resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (pre-baking) was 85 nm.
The obtained silicon wafer was pre-baked (PB) for 60 seconds at a temperature described in the “PB” column of Table 1 on a direct hot plate to form a composition layer. On the wafer on which the resist composition film (composition layer) was thus formed, an ArF excimer stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light] The line and space pattern was subjected to immersion exposure by changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium.
After the exposure, post exposure bake (PEB) is performed on the hot plate at a temperature described in the “PEB” column of Table 1 for 60 seconds, and further with a 2.38 mass% tetramethylammonium hydroxide aqueous solution for 60 seconds. Paddle development was performed to obtain a resist pattern.

  In the obtained resist pattern, the exposure amount at which the line width of the line pattern was 50 nm was defined as effective sensitivity.

<Shape evaluation>
The line pattern produced at the effective sensitivity was observed with a scanning electron microscope. The case where the top shape was close to a rectangle was good, and the case where the top shape was round and the skirt was seen were marked as x. The results are shown in Table 2.

  From the above results, it can be seen that the resist composition of the present invention can produce a resist pattern with a good shape.

  Since the resist composition of the present invention has an excellent resist pattern shape, it is suitable for semiconductor microfabrication and is industrially useful.

Claims (3)

Resin (A1) comprising a structural unit represented by formula (I) and a structural unit having an acid labile group, resin (A2) comprising a structural unit represented by formula (a4-1), and formula (B1 A resist composition containing an acid generator represented by

[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
L ¹ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O— or —CO—.
R ² represents a C 1-10 hydrocarbon group which may have a halogen atom.
R ³ represents an alkyl group having 1 to 10 carbon atoms, a halogen atom or a hydroxyl group.
W represents a hydrocarbon ring having 5 to 18 carbon atoms, and —CH ₂ — contained in the hydrocarbon ring may be replaced with —O— or —CO—.
l represents an integer of 0 to 4.
m represents an integer of 1 to 3.
n represents an integer of 0 to 10. When n is 2 or more, the plurality of R ³ may be the same or different. ]

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

[In the formula (a4-1),
R ^a41 represents a monovalent hydrocarbon group having 1 to 12 carbon atoms, and —CH ₂ — containing the hydrocarbon group may be replaced with —O— or —CO—.
A ^a41 is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a formula (a-g1).

(In the formula (a-g1), s represents 0 or 1.
A ^a42 and A ^a44 each independently represent an ^optionally substituted aliphatic hydrocarbon group having 1 to 5 carbon atoms.
A ^a43 represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent or a single bond.
X ^a41 and X ^a42 each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 7 or less. )
Represents a group represented by
R ^a42 represents a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, the methylene group of which may be substituted with a carbonyloxy group or an oxycarbonyl group.
However, at least one of A ^a41 and R ^a42 is a group having a fluorine atom. ] The resist composition according to claim 1, wherein L ¹ is a single bond.   The resist composition according to claim 1, wherein W is an adamantane ring.

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