JP2011164600A - Resist composition and method for producing resist pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition enabling an excellent line edge roughness to be performed. <P>SOLUTION: The resist composition contains a resin having a structural unit derived from a compound represented by formula (I), an acid generator represented by formula (B1) and a basic compound. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resist composition and a method for manufacturing a resist pattern, and more particularly to a resist composition used for fine processing of a semiconductor and a method for manufacturing a resist pattern.

  A resist composition used for fine processing of a semiconductor using a lithography technique contains a salt that generates an acid upon exposure and a resin.

Patent Document 1 describes a resist composition comprising a resin comprising the following structural units, triphenylsulfonium nonafluorobutanesulfonate as an acid generator, 2,6-diisopropylaniline as a quencher, and a solvent. Yes.

International Publication No. 2009/063829

  Conventional resist compositions may not always satisfy the line edge roughness of the resulting pattern.

［式（Ｉ）中、
Ｒ^１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Ｃ₁〜Ｃ_６アルキル基を表す。
Ｒ^２及びＲ^３は、それぞれ独立に、水素原子、ヒドロキシ基又はＣ₁〜Ｃ_６脂肪族炭化水素基を表す。
ｎは、１〜６の整数を表す。］

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又はＣ₁〜Ｃ₆ペルフルオロアルキル基を表す。
Ｌ^b1は、単結合又は２価のＣ₁〜Ｃ₁₇飽和炭化水素基を表し、前記２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｙは、置換基を有していてもよいＣ₁〜Ｃ_１８脂肪族炭化水素基又は置換基を有していてもよいＣ₃〜Ｃ_１８飽和環状炭化水素基を表し、前記脂肪族炭化水素基及び前記飽和環状炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］ The present invention includes the following inventions [1] to [7].
[1] A resist composition comprising a resin having a structural unit derived from a compound represented by formula (I), an acid generator represented by formula (B1), and a basic compound.

[In the formula (I),
R ¹ represents a hydrogen atom, a halogen atom or a C ₁ -C ₆ alkyl group which may have a halogen atom.
R ² and R ³ each independently represent a hydrogen atom, a hydroxy group or a C _{1 to} C ₆ aliphatic hydrocarbon group.
n represents an integer of 1 to 6. ]

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C _{1 to} C ₆ perfluoroalkyl group.
L ^b1 represents a single bond or a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. Also good.
Y represents a C _{1 to} C ₁₈ aliphatic hydrocarbon group which may have a substituent or a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group which may have a substituent, and the aliphatic hydrocarbon —CH ₂ — contained in the group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]

[2] The resist composition according to [1], wherein R ² and R ³ are hydrogen atoms.
[3] The resist composition according to [1], wherein at least one of R ² and R ³ is a hydroxy group.
[4] The resin further has a structural unit derived from a monomer having an acid labile group and is insoluble or hardly soluble in an alkaline aqueous solution, and the resin that has reacted with an acid can be dissolved in the alkaline aqueous solution. The resist composition according to any one of [1] to [3], which is a resin.
[5] The resist according to any one of [1] to [4], wherein L ^b1 is * —CO—O— (* represents a bond with —C (Q ¹ ) (Q ² ) —). Composition.
[6] The resist composition according to any one of [1] to [5], wherein Z ⁺ is an arylsulfonium cation.

[7] (1) A step of applying the resist composition according to any one of [1] to [6] on a substrate,
(2) a step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer using an exposure machine;
(4) A step of heating the composition layer after exposure,
(5) A method for producing a resist pattern, comprising a step of developing the heated composition layer using a developing device.

  According to the present invention, a pattern having excellent line edge roughness can be obtained.

［式（Ｉ）中、
Ｒ^１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Ｃ₁〜Ｃ_６アルキル基を表す。
Ｒ^２及びＲ^３は、それぞれ独立に、水素原子、ヒドロキシ基又はＣ₁〜Ｃ_６脂肪族炭化水素基を表す。
ｎは、１〜６の整数を表す。］ The resist composition of the present invention comprises a resin, an acid generator and a basic compound.
A resin having at least a structural unit derived from the compound represented by the formula (I) is suitable.

[In the formula (I),
R ¹ represents a hydrogen atom, a halogen atom or a C ₁ -C ₆ alkyl group which may have a halogen atom.
R ² and R ³ each independently represent a hydrogen atom, a hydroxy group or a C _{1 to} C ₆ aliphatic hydrocarbon group.
n represents an integer of 1 to 6. ]

In the present specification, unless otherwise specified, specific substituents to be described later can be applied to any chemical structural formula having the same substituents while appropriately selecting the number of carbon atoms.
Those which can take any of linear, branched or cyclic are included unless otherwise specified, and in the same group, linear, branched or cyclic partial structures are mixed. May be. When stereoisomers exist, all of those stereoisomers are included. Furthermore, each substituent can be a monovalent or divalent substituent depending on the binding site.
Further, "(meth) acrylic monomer" means at least one monomer having a structure of "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- ". Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

In the present specification, examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, 1-methylethyl group (isopropyl group), n-butyl group, 1,1-dimethylethyl group (tert-butyl group), and 2,2-dimethyl group. Ethyl group, 1-methylpropyl group, 2-methylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, 1-ethylpropyl group, n-pentyl group, 1-methylbutyl group, 2-methylbutyl Group, 3-methylbutyl group, n-hexyl group, 1-propylbutyl group, pentyl group, 1-methylpentyl group, 1,4-dimethylhexyl group, heptyl group, 1-methylheptyl group, octyl group, nonyl group, A decyl group, an undecyl group, a dodecyl group, etc. are mentioned.
Examples of the alkyl group that may have a halogen atom include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. Perfluorohexyl group, perchloromethyl group, perbromomethyl group, periodomethyl group and the like.
Examples of the aliphatic hydrocarbon group include a linear or branched alkyl group.

In the compound represented by the formula (I), R ¹ is preferably a hydrogen atom or a methyl group.
R ² and R ³ are each independently preferably a hydrogen atom or a hydroxy group, more preferably both are a hydrogen atom or at least one is a hydroxy group. When one of R ² and R ³ is a hydroxy group, the other is preferably a hydrogen atom or a hydroxy group.
n is preferably 1 to 4, and more preferably 1 to 3.
As for the compound represented by Formula (I), the compound represented by the following is mentioned, for example.

The compound represented by the formula (I) described above can be produced by a method known in the art.
For example, a compound represented by the formula (aa-b) is formed by reacting a compound represented by the formula (aa-a) with magnesium in a solvent, and the obtained formula (aa-b) The compound represented by the formula (I) can be obtained by dropping the compound represented by the formula (aa-c). Here, the solvent is preferably tetrahydrofuran.

［式中、Ｒ^１〜Ｒ^３及びｎは、上記と同じ意味を表す。］

[Wherein R ^{1 to} R ³ and n represent the same meaning as described above. ]

Examples of the compound represented by the formula (aa-a) include monobromomethyl methacrylate and 2-bromoethyl methacrylate.
Examples of the compound represented by the formula (aa-c) include 2-adamantanone and 5-hydroxy-2-adamantanone.

The resin preferably contains a structural unit derived from a monomer having an acid labile group, in addition to the structural unit derived from the compound represented by the formula (I). That is, any of a polymer / oligomer mixture or a copolymer containing these structural units may be used. Such a resin is a resin that is insoluble or hardly soluble in an alkaline aqueous solution, and can be dissolved in an alkaline aqueous solution by the action of an acid.
A resin that becomes alkali-soluble by the action of an acid is produced by polymerizing a monomer having an acid-labile group (hereinafter sometimes referred to as “monomer having an acid-labile group (a1)”). It becomes soluble in alkali by the action of acid. The phrase “becomes soluble in an alkali by the action of an acid” means “being insoluble or hardly soluble in an alkaline aqueous solution before contact with an acid, but soluble in an alkaline aqueous solution after contact with an acid”. . As the monomer (a1) having an acid labile group, one type may be used alone, or two or more types may be used in combination.

<Monomer (a1) having an acid labile group>
The term “acid-labile group” means a group that cleaves a leaving group upon contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group). Examples of the acid labile group include an alkoxycarbonyl group represented by the formula (1) in which —O— is bonded to a tertiary carbon atom (excluding a bridgehead carbon atom of a bridged cyclic hydrocarbon group) (ie, An ester bond having a tertiary alcohol residue). Hereinafter, the group represented by the formula (1) may be referred to as “acid-labile group (1)”.

式（１）中、
Ｒ^a1〜Ｒ^a3は、それぞれ独立に、脂肪族炭化水素基又は飽和環状炭化水素基を表すか或いはＲ^a1及びＲ^a2は互いに結合して環を形成していてもよい。＊は結合手を表す（以下同じ）。

In formula (1),
R ^{a1 to} R ^a3 each independently represents an aliphatic hydrocarbon group or a saturated cyclic hydrocarbon group, or R ^a1 and R ^a2 may be bonded to each other to form a ring. * Represents a bond (same below).

式（１）では、飽和環状炭化水素基は、好ましくはＣ_３〜Ｃ_２０であり、より好ましくはＣ_３〜Ｃ_１２である。 The saturated cyclic hydrocarbon group may be monocyclic or polycyclic, for example, a cycloalkyl group (for example, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, Monocyclic saturated cyclic hydrocarbon groups such as cyclooctyl groups; groups obtained by hydrogenating condensed aromatic hydrocarbon groups (for example, hydronaphthyl groups), bridged cyclic hydrocarbon groups (for example, adamantyl groups, norbornyl) Group, methyl norbornyl group) and the like. Further, a group in which a bridged ring (for example, norbornane ring) and a single ring (for example, cycloheptane ring, cyclohexane ring) or a polycyclic (for example, decahydronaphthalene ring) or bridged rings are condensed as shown below. Groups; groups in which these are combined (methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group) and the like.

In the formula (1), the saturated cyclic hydrocarbon group is preferably C _{3 to} C ₂₀ , more preferably C _{3 to} C ₁₂ .

Examples of the ring formed by combining R ^a1 and R ^a2 with each other include a saturated cyclic hydrocarbon group and an aromatic hydrocarbon group. Such rings are preferably _C 3 _{-C 20,} more preferably _C 3 _{-C 12.}

Examples of the acid labile group (1) include a 1,1-dialkylalkoxycarbonyl group (in the group (1), R ^{a1 to} R ^a3 are alkyl groups, preferably a tert-butoxycarbonyl group), 2-alkyl-2-adamantyloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and a carbon atom form an adamantyl group, and R ^a3 is an alkyl group) and 1- (1-adamantyl)- 1-alkylalkoxycarbonyl groups (in the formula (1), R ^a1 and R ^a2 are alkyl groups and R ^a3 is an adamantyl group) and the like.

  The monomer (a1) having an acid labile group is preferably a monomer having an acid labile group (1) and a carbon-carbon double bond, more preferably an acid labile group (1). (Meth) acrylic monomer having

Among the (meth) acrylic monomers having the acid-labile group (1), those having a C _{5 to} C ₂₀ saturated cyclic hydrocarbon group are preferred. If a resin obtained by polymerizing the monomer (a1) having a bulky structure such as a saturated cyclic hydrocarbon group is used, the resolution of the resist can be improved.

  Among the (meth) acrylic monomers having the acid labile group (1) and the saturated cyclic hydrocarbon group, the acid labile group represented by the formula (a1-1) or the formula (a1-2) Monomers having are preferred. These may be used alone or in combination of two or more.

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の整数を表す。但しＬ^a1及びＬ^a2で列挙した−Ｏ−等は、それぞれ、左側で式（ａ１−１）及び式（ａ１−２）の−ＣＯ−と結合し、右側でアダマンチル基又はシクロへキシル基と結合することを意味する。
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、Ｃ₁〜Ｃ₈脂肪族炭化水素基又はＣ₃〜Ｃ₁₀飽和環状炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０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—, and k1 represents an integer of 1 to 7. However, —O— and the like enumerated for L ^a1 and L ^a2 are respectively bonded to —CO— of the formula (a1-1) and the formula (a1-2) on the left side, and to an adamantyl group or cyclohexyl group on the right side. Means to join.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent a C _{1 to} C ₈ aliphatic hydrocarbon group or a C _{3 to} C ₁₀ saturated cyclic hydrocarbon group.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.

In the formula (a1-1) and the formula (a1-2), L ^a1 and L ^a2 are preferably, -O- or _{-O- (CH 2) f1 -CO-} O- and is (wherein f1 is 1 to 4), and more preferably -O-.
R ^a4 and R ^a5 are preferably methyl groups.
The aliphatic hydrocarbon group for R ^a6 and R ^a7 is preferably C ₆ or less. Saturated cyclic hydrocarbon group is preferably C ₈ or less, more preferably C 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.
k1 is preferably an integer of 1 to 4, more preferably 1.

  As a monomer (a1-1) which has an adamantyl group, the following are mentioned, for example. Among them, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate and 2-isopropyl-2-adamantyl (meth) acrylate are preferable, and those in the form of methacrylate are more preferable.

  As a monomer (a1-2) which has a cyclohexyl group, the following are mentioned, for example. Among these, 1-ethyl-1-cyclohexyl (meth) acrylate is preferable, and 1-ethyl-1-cyclohexyl methacrylate is more preferable.

  The content of the structural unit derived from the monomer represented by the formula (a1-1) or the formula (a1-2) in the resin is usually 10 to 95 mol%, preferably 15 to 90, in all units of the resin. It is mol%, More preferably, it is 20-85 mol%.

  Examples of the monomer having an acid labile group (1) and a carbon-carbon double bond include a monomer having a norbornene ring represented by the formula (a1-3). Since the resin having a structural unit derived from the monomer (a1-3) having an acid labile group has a bulky structure, the resolution of the resist can be improved. Furthermore, the monomer (a1-3) having an acid labile group can improve the resistance to dry etching of a resist by introducing a rigid norbornane ring into the main chain of the resin.

式（ａ１−３）中、
Ｒ^a9は、水素原子、置換基（例えば、ヒドロキシ基）を有していてもよいＣ₁〜Ｃ₃脂肪族炭化水素基、カルボキシ基、シアノ基又は基−ＣＯＯＲ^a13を表す。Ｒ^a13は、Ｃ₁〜Ｃ₈脂肪族炭化水素基又はＣ₃〜Ｃ₈飽和環状炭化水素基を表し、前記脂肪族炭化水素基及び前記飽和環状炭化水素基の水素原子はヒドロキシ基で置換されていてもよく、前記脂肪族炭化水素基及び前記飽和環状炭化水素基の−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｒ^a10〜Ｒ^a12は、それぞれ独立に、Ｃ₁〜Ｃ₁₂脂肪族炭化水素基又はＣ₃〜Ｃ₁₂飽和環状炭化水素基を表すか、或いはＲ^a10及びＲ^a11は互いに結合して環を形成していてもよく、前記脂肪族炭化水素基及び前記飽和環状炭化水素基の水素原子はヒドロキシ基等で置換されていてもよく、前記脂肪族炭化水素基及び前記飽和環状炭化水素基の−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。

In formula (a1-3),
R ^a9 represents a hydrogen atom, a C ₁ -C ₃ aliphatic hydrocarbon group, a carboxy group, a cyano group or a group —COOR ^a13 which may have a substituent (for example, a hydroxy group). R ^a13 represents a C _{1 to} C ₈ aliphatic hydrocarbon group or a C _{3 to} C ₈ saturated cyclic hydrocarbon group, and a hydrogen atom of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group is substituted with a hydroxy group. And —CH ₂ — in the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be replaced by —O— or —CO—.
R ^{a10 to} R ^a12 each independently represent a C _{1 to} C ₁₂ aliphatic hydrocarbon group or a C _{3 to} C ₁₂ saturated cyclic hydrocarbon group, or R ^a10 and R ^a11 are bonded to each other to form a ring. The aliphatic hydrocarbon group and the hydrogen atom of the saturated cyclic hydrocarbon group may be substituted with a hydroxy group or the like, and —CH of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group _2- may be replaced by -O- or -CO-.

Examples of the aliphatic hydrocarbon group which may have a substituent for R ^a9 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group.
^Examples of R ^a13 include a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, and a 2-oxo-oxolan-4-yl group.
Examples of R ^{a10 to} R ^a12 include a methyl group, an ethyl group, a cyclohexyl group, a methylcyclohexyl group, a hydroxycyclohexyl group, an oxocyclohexyl group, and an adamantyl group.
Examples of the ring formed by R ^a10 , R ^a11 and the carbon to which they are bonded include saturated cyclic hydrocarbon groups, and specific examples include a cyclohexyl group and an adamantyl group.

  Examples of the monomer (a1-3) having a norbornene ring include, for example, 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene-2 -1-methylcyclohexyl carboxylate, 2-methyl-2-adamantyl 5-norbornene-2-carboxylate, 2-ethyl-2-adamantyl 5-norbornene-2-carboxylate, 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 -Oxocyclohexyl) ethyl, 5-norbornene-2-carboxylic acid 1- (1-adap Pentyl) -1-methylethyl and the like.

  The content of the structural unit derived from the monomer represented by the formula (a1-3) in the resin is usually 10 to 95 mol%, preferably 15 to 90 mol%, more preferably in all units of the resin. Is 20 to 85 mol%.

式（ａ１−４）中、
Ｒ¹⁰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Ｃ₁〜Ｃ₆アルキル基を表す。
Ｒ¹¹は、それぞれ独立に、ハロゲン原子、ヒドロキシ基、Ｃ₁〜Ｃ₆アルキル基、Ｃ₁〜Ｃ₆アルコキシ基、Ｃ₂〜Ｃ₄アシル基、Ｃ₂〜Ｃ₄アシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｌａは０〜４の整数を表す。ｌａが２以上の整数である場合、複数のＲ¹¹は同一であっても異なってもよい。
Ｒ¹²及びＲ¹³はそれぞれ独立に、水素原子又はＣ₁〜Ｃ₁₂炭化水素基を表す。
Ｘ^ａ２は、単結合又は置換基を有していてもよい２価のＣ₁〜Ｃ₁₇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−ＣＯ−、−Ｏ−、−Ｓ−、−ＳＯ_２−又は−Ｎ（Ｒ^ｃ）−で置き換わっていてもよい。Ｒ^ｃは、水素原子又はＣ₁〜Ｃ₆アルキル基を表す。
Ｙ^ａ３は、Ｃ₁〜Ｃ₁₂脂肪族炭化水素基、Ｃ₃〜Ｃ₁₈飽和環状炭化水素基又はＣ₆〜Ｃ₁₈芳香族炭化水素基であり、該脂肪族炭化水素基、飽和環状炭化水素基及び芳香族炭化水素基は、置換基を有していてもよい。］ Examples of the monomer having the acid labile group (1) and the carbon-carbon double bond include a monomer (a1-4) represented by the formula (a1-4).

In formula (a1-4),
R ¹⁰ represents a hydrogen atom, a halogen atom or a C ₁ -C ₆ alkyl group which may have a halogen atom.
R ¹¹ is independently a halogen atom, a hydroxy group, a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ alkoxy group, a C ₂ -C ₄ acyl group, a C ₂ -C ₄ acyloxy group, an acryloyl group or a methacryloyl group. Represents a group.
la represents an integer of 0 to 4. When la is an integer of 2 or more, the plurality of R ¹¹ may be the same or different.
R ¹² and R ¹³ each independently represents a hydrogen atom or a C _{1 to} C ₁₂ hydrocarbon group.
X ^a2 represents a divalent C _{1 to} C ₁₇ saturated hydrocarbon group which may have a single bond or a substituent, and —CH ₂ — contained in the saturated hydrocarbon group represents —CO—, —O -, - S -, - SO 2 - or -N ^{(R c)} - it may be replaced by. R ^c represents a hydrogen atom or a C ₁ -C ₆ alkyl group.
Y ^a3 is a C _{1 to} C ₁₂ aliphatic hydrocarbon group, a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group or a C _{6 to} C ₁₈ aromatic hydrocarbon group, and the aliphatic hydrocarbon group and saturated cyclic hydrocarbon The group and the aromatic hydrocarbon group may have a substituent. ]

Examples of the alkyl group that may have a halogen atom include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. Perfluorohexyl group, perchloromethyl group, perbromomethyl group, periodomethyl group and the like.
Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentoxy group, and an n-hexoxy group. .
Examples of the acyl group include acetyl, propionyl, butyryl and the like.
Examples of the acyloxy group include acetyloxy, propionyloxy, butyryloxy and the like.
Examples of the hydrocarbon group include an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group, and an aromatic hydrocarbon group.
As aromatic hydrocarbon group, phenyl group, naphthyl group, anthranyl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl Groups, anthryl groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the saturated hydrocarbon group include aliphatic hydrocarbons and saturated cyclic hydrocarbons.

In formula (a1-4), the alkyl groups of R ¹⁰ and R ¹¹ are preferably C _{1 to} C ₄ , more preferably C _{1 to} C ₂ , and particularly preferably a methyl group.
As the alkoxy group for R ¹¹ , C _{1 to} C ₂ are more preferable, and a methoxy group is particularly preferable.
Examples of the hydrocarbon group for R ¹² and R ¹³ include isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group, cyclohexyl group, adamantyl group, A 2-alkyl-2-adamantyl group, a 1- (1-adamantyl) -1-alkyl group, an isobornyl group, and the like are preferable.
Examples of the group that may be substituted with the groups X ^a2 and Y ^a3 include a halogen atom, a hydroxy group, a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ alkoxy group, a C ₂ -C ₄ acyl group, and a C ₂ -C ₄ acyloxy group, and the like. Of these, a hydroxy group is preferable.

As a monomer (a1-4), the following monomers are mentioned, for example.

  The content of the structural unit derived from the monomer represented by the formula (a1-4) in the resin is usually 10 to 95 mol%, preferably 15 to 90 mol%, more preferably in all units of the resin. Is 20 to 85 mol%.

  Examples of the monomer having an acid labile group (1) and a carbon-carbon double bond include monomers represented by the formula (a1-5).

式（ａ１−５）中、
Ｒ^３１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Ｃ₁〜Ｃ_６アルキル基を表す。
Ｌ^１〜Ｌ^３は、オキシ基、チオキシ基又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−で表される基を表す。ここで、ｋ１は１〜７の整数を表し、＊はカルボニル基（−ＣＯ−）との結合手である。
Ｚ^１は、単結合又はＣ₁〜Ｃ_６アルキレン基であり、該アルキレン基中に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
ｓ１及びｓ２は、それぞれ独立して、０〜４の整数を表す。 Examples of the monomer represented by the formula (a1-5) include the following monomers.

In formula (a1-5),
R ³¹ represents a hydrogen atom, a halogen atom or a C ₁ -C ₆ alkyl group which may have a halogen atom.
L ^{1 to} L ³ represent a group represented by an oxy group, a thioxy group, or ^* —O— (CH ₂ ) _k1 —CO—O—. Here, k1 represents an integer of 1 to 7, and * is a bond with a carbonyl group (—CO—).
Z ¹ is a single bond or a C ₁ -C ₆ alkylene group, and —CH ₂ — contained in the alkylene group may be replaced by —O— or —CO—.
s1 and s2 each independently represents an integer of 0 to 4.

In formula (a1-5), R ³¹ is preferably a hydrogen atom, a methyl group and a trifluoromethyl group, more preferably a hydrogen atom and a methyl group.
L ¹ is preferably an oxygen atom.
One of L ² and L ³ is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
As for s2, 0-2 are preferable.
Z ¹ is preferably a single bond or —CH ₂ —CO—O—, and more preferably a single bond.

Specific examples of the monomer represented by the formula (a1-5) include the following compounds.

  The content of the structural unit derived from the monomer represented by the formula (a1-5) in the resin is usually 5 to 90 mol%, preferably 10 to 85 mol% in all units of the resin (A). More preferably, it is 15-80 mol%.

Furthermore, a monomer that derives another structural unit having an acid labile group (1) and a carbon-carbon double bond in the molecule may be used.
Examples of such a monomer include the following monomers.

  When the resin has structural units derived from other acid labile monomers, the content thereof is 10 to 95 mol%, preferably 15 to 90 mol%, based on all units of the resin (A). More preferably, it is 20-85 mol%.

The resin (A) is preferably a co-polymerization of a monomer (a1) having an acid labile group and a monomer having no acid labile group (hereinafter sometimes referred to as “acid stable monomer”). It is a coalescence. An acid stable monomer may be used individually by 1 type, and may use 2 or more types together.
When the resin (A) is a copolymer of a monomer (a1) having an acid labile group and an acid stable monomer, the structural units derived from the monomer (a1) having an acid labile group are all Preferably it is 10-80 mol% with respect to 100 mol% of structural units, More preferably, it is 20-60 mol%. Further, the structural unit derived from the monomer having an adamantyl group (particularly the monomer (a1-1) having an acid labile group) is converted to 15 mol per 100 mol% of the monomer (a1) having an acid labile group. It is preferable to set it as mol% or more. When the ratio of the monomer having an adamantyl group increases, the dry etching resistance of the resist is improved.

  As the acid stable monomer, those having a hydroxy group or a lactone ring are preferred. Derived from an acid stable monomer having a hydroxy group (hereinafter referred to as “acid stable monomer having a hydroxy group (a2)”) or an acid stable monomer having a lactone ring (hereinafter referred to as “acid stable monomer having a lactone ring (a3)”) If a resin having a structural unit to be used is used, the resolution of the resist and the adhesion to the substrate can be improved.

<Acid-stable monomer having a hydroxy group (a2)>
When the resist composition is used for KrF excimer laser exposure (248 nm), high energy beam exposure such as electron beam or EUV light, the acid-stable monomer (a2) having a hydroxy group has an acid having a phenolic hydroxyl group which is a hydroxystyrene. It is preferable to use a stable monomer (a2-0). When using short wavelength ArF excimer laser exposure (193 nm) or the like, an acid stable monomer having a hydroxyadamantyl group represented by formula (a2-1) should be used as the acid stable monomer having a hydroxy group (a2). Is preferred. The acid-stable monomer (a2) having a hydroxy group may be used alone or in combination of two or more.

式（ａ２−０）中、
Ｒ^８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Ｃ₁〜Ｃ₆アルキル基を表す。
Ｒ^９は、ハロゲン原子、ヒドロキシ基、Ｃ₁〜Ｃ₆アルキル基、Ｃ₁〜Ｃ₆アルコキシ基、Ｃ₂〜Ｃ₄アシル基、Ｃ₂〜Ｃ₄アシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^９は同一であっても異なってもよい。 Examples of the monomer (a2-0) having a phenolic hydroxyl group include styrene monomers such as p- or m-hydroxystyrene represented by the formula (a2-0).

In formula (a2-0),
R ⁸ represents a C ₁ -C ₆ alkyl group which may have a hydrogen atom, a halogen atom or a halogen atom.
R ⁹ represents a halogen atom, a hydroxy group, a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ alkoxy group, a C ₂ -C ₄ acyl group, a C ₂ -C ₄ acyloxy group, an acryloyl group or a methacryloyl group.
ma represents an integer of 0 to 4. When ma is an integer of 2 or more, the plurality of R ⁹ may be the same or different.

The alkyl group in R ^8, preferably C ₁ -C ₄ alkyl group, C ₁ -C more preferably ₂ alkyl group, a methyl group is particularly preferred.
The alkoxy group is preferably a C ₁ -C ₄ alkoxy group, more preferably C ₁ -C ₂ alkoxy group, a methoxy group is particularly preferred.
ma is preferably 0 to 2, more preferably 0 or 1, and particularly preferably 0.

When obtaining a copolymer resin having a structural unit derived from a monomer having such a phenolic hydroxyl group, the corresponding (meth) acrylic acid ester monomer, acetoxystyrene, and styrene are radically polymerized and then deacetylated with an acid. Can be obtained.
Examples of the monomer having a phenolic hydroxyl group include the following monomers.

  Of the above monomers, 4-hydroxystyrene or 4-hydroxy-α-methylstyrene is particularly preferred.

  The content of the structural unit derived from the monomer represented by the formula (a2-0) in the resin is usually from 5 to 90 mol%, preferably from 10 to 85 mol%, more preferably in all units of the resin. Is 15 to 80 mol%.

式（ａ２−１）中、
Ｌ^a3は、−Ｏ−又は−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−を表し、
ｋ２は１〜７の整数を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。 Examples of the acid stable monomer having a hydroxyadamantyl group include a monomer represented by the formula (a2-1).

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

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

  As an acid stable monomer (a2-1) which has a hydroxyadamantyl group, the following are mentioned, for example. Among them, 3-hydroxy-1-adamantyl (meth) acrylate, 3,5-dihydroxy-1-adamantyl (meth) acrylate, and 1- (3,5-dihydroxy-1-adamantyloxycarbonyl) methyl (meth) acrylate are Preferably, 3-hydroxy-1-adamantyl (meth) acrylate and 3,5-dihydroxy-1-adamantyl (meth) acrylate are more preferable, 3-hydroxy-1-adamantyl methacrylate and 3,5-dihydroxy-1-adamantyl methacrylate Is more preferable.

  The content of the structural unit derived from the monomer represented by the formula (a2-1) in the resin is usually from 3 to 45 mol%, preferably from 5 to 40 mol%, more preferably in all units of the resin. Is 5 to 35 mol%.

<Acid-stable monomer having a lactone ring (a3)>
The lactone ring possessed by the acid stable monomer (a3) may be, for example, a monocyclic ring such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a monocyclic lactone ring and another ring. The condensed ring may be used. Among these lactone rings, a γ-butyrolactone ring and a condensed ring of a γ-butyrolactone ring and another ring are preferable.

  The acid-stable monomer (a3) having a lactone ring is preferably represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3). These 1 type may be used independently and may use 2 or more types together.

式（ａ３−１）〜式（ａ３−３）中、
Ｌ^a4〜Ｌ^a6は、それぞれ独立に、−Ｏ−又は−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−を表す。
ｋ３は１〜７の整数を表す。
Ｒ^a18〜Ｒ^a20は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a21は、Ｃ₁〜Ｃ₄脂肪族炭化水素基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a22及びＲ^a23は、それぞれ独立に、カルボキシ基、シアノ基又はＣ₁〜Ｃ₄脂肪族炭化水素基を表す。
ｑ１及びｒ１は、それぞれ独立に０〜３の整数を表す。ｐ１、ｑ１又はｒ１が２以上のとき、それぞれ、複数のＲ^a21、Ｒ^a22又はＲ^a23は、互いに同一でも異なってもよい。

In formula (a3-1) to formula (a3-3),
L ^{a4 to} L ^a6 each independently represent —O— or —O— (CH ₂ ) _k3 —CO—O—.
k3 represents an integer of 1 to 7.
R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents a C _{1 to} C ₄ aliphatic hydrocarbon group.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or a C ₁ -C ₄ aliphatic hydrocarbon group.
q1 and r1 each independently represents an integer of 0 to 3. When p1, q1 or r1 is 2 or more, a plurality of R ^a21 , R ^a22 or R ^a23 may be the same as or different from each other.

In the formula (a3-1) to the formula (a3-3), examples of L ^{a4 to} L ^a6 include those described for L ^a3 .
L ^{a4 to} L ^a6 are each independently preferably —O—, —O— (CH ₂ ) _d1 —CO—O— (wherein d1 is an integer of 1 to 4), more preferably -O-. However, —O— and the like enumerated in L ^{a4 to} L ^a6 mean that they are bonded to —CO— of the formula (a3-1) to the formula (a3-3) on the left side and to the lactone ring on the right side. To do.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1 to r1 are each independently preferably 0 to 2, more preferably 0 or 1.

Examples of the acid stable monomer (a3-1) having a γ-butyrolactone ring include the following.

  Examples of the acid stable monomer (a3-2) having a condensed ring of γ-butyrolactone ring and norbornane ring include the following.

  Examples of the acid stable monomer (a3-3) having a condensed ring of γ-butyrolactone ring and cyclohexane ring include the following.

Among acid-stable monomers (a3) having a lactone ring, (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yl, (meth) acrylic Acid tetrahydro-2-oxo-3-furyl, 2- (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yloxy) -2-oxoethyl (meth) acrylate Are preferred, and those in the form of methacrylate are more preferred.

  Content of the structural unit derived from the monomer represented by Formula (a3-1), Formula (a3-2) or Formula (a3-3) in the resin is usually 5 to 70 mol% in all units of the resin. Yes, preferably 10 to 65 mol%, more preferably 10 to 60 mol%.

<Other acid stable monomers (a4)>
Examples of the other acid stable monomer (a4) include maleic anhydride represented by formula (a4-1), itaconic anhydride represented by formula (a4-2), and formula (a4-3). And acid-stable monomers having a norbornene ring.

式（ａ４−３）中、
Ｒ^a25及びＲ^a26は、それぞれ独立に、水素原子、置換基（例えば、ヒドロキシ基）を有していてもよいＣ₁〜Ｃ₃脂肪族炭化水素基、シアノ基、カルボキシ基又は基−ＣＯＯＲ^a27を表すか、或いはＲ^a25及びＲ^a26は互いに結合して−ＣＯ−Ｏ−ＣＯ−を形成し、
Ｒ^a27は、Ｃ₁〜Ｃ₃₆脂肪族炭化水素基又はＣ₃〜Ｃ₃₆飽和環状炭化水素基を表し、脂肪族炭化水素基及び飽和環状炭化水素基の−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。但し−ＣＯＯＲ^a27が酸不安定基となるものは除く（即ちＲ^a27は、３級炭素原子が−Ｏ−と結合するものを含まない）。

In formula (a4-3),
R ^a25 and R ^a26 each independently represent a hydrogen atom, a C ₁ -C ₃ aliphatic hydrocarbon group which may have a substituent (for example, a hydroxy group), a cyano group, a carboxy group or a group —COOR ^a27. R ^a25 and R ^a26 are bonded to each other to form —CO—O—CO—,
R ^a27 represents a C _{1 to} C ₃₆ aliphatic hydrocarbon group or a C _{3 to} C ₃₆ saturated cyclic hydrocarbon group, and —CH ₂ — of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group is —O— or It may be replaced by -CO-. However, those in which —COOR ^a27 is an acid labile group are excluded (that is, R ^a27 does not include those in which a tertiary carbon atom is bonded to —O—).

^Examples of the aliphatic hydrocarbon group which may have a substituent for R ^a25 and R ^a26 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group.
The aliphatic hydrocarbon group for R ^a27 is preferably C _{1 to} C ₈ , more preferably C _{1 to} C ₆ . The saturated cyclic hydrocarbon group is preferably C _{4 to} C ₃₆ , more preferably C _{4 to} C ₁₂ .
^Examples of R ^a27 include a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, and a 2-oxo-oxolan-4-yl group.

  Examples of the acid-stable monomer (a4-3) having a norbornene ring include 2-norbornene, 2-hydroxy-5-norbornene, 5-norbornene-2-carboxylic acid, methyl 5-norbornene-2-carboxylate, 5- Examples include norbornene-2-carboxylic acid 2-hydroxy-1-ethyl, 5-norbornene-2-methanol, and 5-norbornene-2,3-dicarboxylic acid anhydride.

  Content of the structural unit derived from the monomer represented by Formula (a4-1), Formula (a4-2), or Formula (a4-3) in the resin is usually 2 to 40 mol% in all units of the resin. Yes, preferably 3-30 mol%, more preferably 5-20 mol%.

  A preferred resin (A) is a copolymer obtained by polymerizing at least a monomer (a1) having an acid labile group, an acid stable monomer (a2) having a hydroxy group, and / or an acid stable monomer (a3) having a lactone ring. It is a polymer. In this preferred copolymer, the monomer (a1) having an acid labile group is more preferably at least one of a monomer (a1-1) having an adamantyl group and a monomer (a1-2) having a cyclohexyl group. A species (more preferably a monomer (a1-1) having an adamantyl group), and an acid stable monomer (a2) having a hydroxy group, preferably an acid stable monomer (a2-1) having a hydroxyadamantyl group, and a lactone The acid-stable monomer (a3) having a ring is more preferably an acid-stable monomer (a3-1) having a γ-butyrolactone ring and an acid-stable monomer (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring At least one of the following. Resin (A) can be manufactured by a well-known polymerization method (for example, radical polymerization method).

The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less).
A weight average molecular weight is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis, and the detailed analysis conditions of this analysis are explained in full detail in the Example of this application.
It is preferable that content of resin (A) is 80 mass% or more in solid content of a composition.
In the present specification, the “solid content in the composition” means the total of resist composition components excluding the solvent (E) described later. The solid content in the composition and the content of the resin (A) relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又はＣ₁〜Ｃ₆ペルフルオロアルキル基を表す。
Ｌ^b1は、単結合又は２価のＣ₁〜Ｃ₁₇飽和炭化水素基を表し、前記２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｙは、置換基を有していてもよいＣ₁〜Ｃ_１８脂肪族炭化水素基又は置換基を有していてもよいＣ₃〜Ｃ_１８飽和環状炭化水素基を表し、前記脂肪族炭化水素基及び前記飽和環状炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］ <Acid generator (hereinafter sometimes referred to as "acid generator (B)")>
The acid generator (B) is a sulfonate represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C _{1 to} C ₆ perfluoroalkyl group.
L ^b1 represents a single bond or a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. Also good.
Y represents a C _{1 to} C ₁₈ aliphatic hydrocarbon group which may have a substituent or a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group which may have a substituent, and the aliphatic hydrocarbon —CH ₂ — contained in the group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]

  Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. It is done.

In formula (B1), Q ¹ and Q ² are each independently preferably a perfluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group include a linear alkylene group, a branched alkylene group, a monocyclic or polycyclic saturated cyclic hydrocarbon group, and a combination of two or more of these groups But you can.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , 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, heptadecane-1, Linear alkylene groups such as 17-diyl group, methylidene group, ethylidene group, propylidene group, 2-propylidene group;
A straight-chain alkylene, an alkyl group (in particular, C ₁ -C ₄ alkyl group, e.g., methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec- butyl group, tert- butyl group, etc.) the side chain of For example, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group Branched alkylene such as 2-methyl-1,4-butylene group;
Monocyclic saturated cyclic hydrocarbon groups which are cycloalkylene groups such as 1,3-cyclobutylene group, 1,3-cyclopentylene group, 1,4-cyclohexylene group, 1,5-cyclooctylene group;
Examples thereof include polycyclic saturated cyclic hydrocarbon groups such as 1,4-norbornylene group, 2,5-norbornylene group, 1,5-adamantylene group, 2,6-adamantylene group and the like.

Examples of the group in which —CH ₂ — contained in the saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include formula (b1-1) to formula (b1-6). L ^b1 is preferably any one of formulas (b1-1) to (b1-4), more preferably formula (b1-1) or formula (b1-2). Incidentally, the formula (b1-1) ~ formula (b1-6) are described together the left and right in the equation (B1), the left ^{C (Q 1) (Q 2} ) - bound to, the right side Combines with -Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6).

式（ｂ１−１）〜式（ｂ１−６）中、
Ｌ^b2は、単結合又はＣ₁〜Ｃ₁₅飽和炭化水素基を表す。
Ｌ^b3は、単結合又はＣ₁〜Ｃ₁₂飽和炭化水素基を表す。
Ｌ^b4は、Ｃ₁〜Ｃ₁₃飽和炭化水素基を表す。但しＬ^b3及びＬ^b4の炭素数上限は１３である。
Ｌ^b5は、Ｃ₁〜Ｃ₁₅飽和炭化水素基を表す。
Ｌ^b6及びＬ^b7は、それぞれ独立に、Ｃ₁〜Ｃ₁₅飽和炭化水素基を表す。但しＬ^b6及びＬ^b7の炭素数上限は１６である。
Ｌ^b8は、Ｃ₁〜Ｃ₁₄飽和炭化水素基を表す。
Ｌ^b9及びＬ^b10は、それぞれ独立に、Ｃ₁〜Ｃ₁₁飽和炭化水素基を表す。但しＬ^ｂ９及びＬ^ｂ１０の炭素数上限は１２である。

In formula (b1-1) to formula (b1-6),
L ^b2 represents a single bond or a C _{1 to} C ₁₅ saturated hydrocarbon group.
L ^b3 represents a single bond or a C _{1 to} C ₁₂ saturated hydrocarbon group.
L ^b4 represents a C _{1 to} C ₁₃ saturated hydrocarbon group. However, the upper limit of the carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a C _{1 to} C ₁₅ saturated hydrocarbon group.
L ^b6 and L ^b7 each independently represent a C _{1 to} C ₁₅ saturated hydrocarbon group. However, the upper limit of the carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a C _{1 to} C ₁₄ saturated hydrocarbon group.
L ^b9 and L ^b10 each independently represent a C _{1 to} C ₁₁ saturated hydrocarbon group. However, the upper limit of the carbon number of L ^b9 and L ^b10 is 12.

Among these, a divalent group represented by the formula (b1-1) is preferable, and a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond or —CH ₂ — is more preferable.
L ^b1 is particularly preferably * —CO—O— (* represents a bond with —C (Q ¹ ) (Q ² ) —).

Examples of the divalent group represented by the formula (b1-1) include the following.

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

Examples of the divalent group represented by the formula (b1-3) include the following.

Examples of the divalent group represented by the formula (b1-4) include the following.

Examples of the divalent group represented by the formula (b1-5) include the following.

Examples of the divalent group represented by the formula (b1-6) include the following.

The saturated hydrocarbon group for L ^b1 may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, a carboxy group, a C _{6 to} C ₁₈ aromatic hydrocarbon group, a C _{7 to} C ₂₁ aralkyl group, a C _{2 to} C ₄ acyl group, and a glycidyloxy group. .
Examples of the aralkyl group include benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl group, naphthylethyl group, and the like.

Examples of the aliphatic hydrocarbon group of Y, C ₁ ~C ₆ alkyl group is preferable.
Examples of the substituent of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group include a halogen atom (excluding a fluorine atom), a hydroxy group, an oxo group, a C _{1 to} C ₁₂ aliphatic hydrocarbon group, and a hydroxy group-containing C. ₁ -C ₁₂ aliphatic hydrocarbon group, C ₃ -C ₁₆ saturated cyclic hydrocarbon group, C ₁ -C ₁₂ alkoxy groups, C ₆ -C ₁₈ aromatic hydrocarbon group, C ₇ -C ₂₁ aralkyl group, C ₂ -C ₄ acyl group, glycidyloxy group, or _{- (CH 2) j2 -O-} CO-R b1 group (wherein, R ^b1 is, C ₁ -C ₁₆ aliphatic hydrocarbon group, C ₃ -C ₁₆ saturated cyclic Represents a hydrocarbon group or a C _{6 to} C ₁₈ aromatic hydrocarbon group, j2 represents an integer of 0 to 4, and the like. The aliphatic hydrocarbon group, saturated cyclic hydrocarbon group, aromatic hydrocarbon group, aralkyl group, and the like, which are substituents for Y, may further have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxy group, and an oxo group.
Examples of the hydroxy group-containing aliphatic hydrocarbon group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the group in which —CH ₂ — in the aliphatic hydrocarbon group and saturated cyclic hydrocarbon group of Y is replaced by —O—, —SO ₂ — or —CO— include, for example, a cyclic ether group (—CH ₂ — is — O-, substituted groups), a saturated cyclic hydrocarbon group having an oxo group (-CH ₂ - is replaced by -CO- groups), sultone Hajime Tamaki (adjacent two -CH ₂ -, respectively, -O - or -SO ₂ - in the replaced groups) or lactone Hajime Tamaki (two adjacent -CH ₂ -, respectively, -O- or -CO- with replaced groups) and the like.

In particular, examples of the saturated cyclic hydrocarbon group for Y include groups represented by formulas (Y1) to (Y26).

  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 Y, which is a saturated cyclic hydrocarbon group substituted with an aliphatic hydrocarbon group, include the following.

  Examples of Y that is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group include the following.

  Examples of Y, which is a saturated cyclic hydrocarbon group substituted with an aromatic hydrocarbon group, include the following.

Examples of Y that is a saturated cyclic hydrocarbon group in which the — (CH ₂ ) _j2 —O—CO—R ^b1 group is substituted include the following.

  Y is preferably an adamantyl group which may have a substituent (for example, an oxo group or the like), more preferably an adamantyl group or an oxoadamantyl group.

Examples of the sulfonate anion in the salt represented by the formula (B1) include, for example, the following formulas (b1-1-1) to (b1-1-1-) in which the substituent L ^b1 is the formula (b1-1). The anion represented by 9) is preferred. In the following formulae, the definition of the substituent has the same meaning as described above, and the substituents R ^b2 and R ^b3 each independently represent a C _{1 to} C ₄ aliphatic hydrocarbon group (preferably a methyl group).

Saturated cyclic substituted with a sulfonate anion or an aliphatic hydrocarbon group containing Y which is an aliphatic hydrocarbon group or an unsubstituted saturated cyclic hydrocarbon group and a divalent group represented by the formula (b1-1) Examples of the sulfonate anion containing Y which is a hydrocarbon group and the divalent group represented by the formula (b1-1) include the following.

As the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with — (CH ₂ ) _j2 —O—CO—R ^b1 group and a divalent group represented by the formula (b1-1), For example, the following are mentioned.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (b1-1) include the following: Things.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with an aromatic hydrocarbon group or an aralkyl group and a divalent group represented by the formula (b1-1) include the following. It is done.

Examples of the sulfonate anion containing Y which is a cyclic ether and the divalent group represented by the formula (b1-1) include the following.

Examples of the sulfonate anion containing Y which is a lactone ring and the divalent group represented by the formula (b1-1) include the following.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon having an oxo group and a divalent group represented by the formula (b1-1) include the following.

Examples of the sulfonate anion containing Y which is a sulfone ring and a divalent group represented by the formula (b1-1) include the following.

Saturated cyclic substituted with a sulfonate anion or an aliphatic hydrocarbon group containing Y which is an aliphatic hydrocarbon group or an unsubstituted saturated cyclic hydrocarbon group and a divalent group represented by the formula (b1-2) Examples of the sulfonate anion containing Y which is a hydrocarbon group and the divalent group represented by the formula (b1-2) include the following.

As the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with — (CH ₂ ) _j2 —O—CO—R ^b1 group and a divalent group represented by the formula (b1-2), For example, the following are mentioned.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (b1-2) include the following: Things.

  Examples of the sulfonate anion containing Y, which is a saturated cyclic hydrocarbon group substituted with an aromatic hydrocarbon group, and a divalent group represented by the formula (b1-2) include the following.

  Examples of the sulfonate anion containing Y which is a cyclic ether and the divalent group represented by the formula (b1-2) include the following.

  Examples of the sulfonate anion containing Y which is a lactone ring and the divalent group represented by the formula (b1-2) include the following.

  Examples of the sulfonate anion containing Y having an oxo group and the divalent group represented by the formula (b1-2) include the following.

  Examples of the sulfonate anion containing Y which is a sultone ring and the divalent group represented by the formula (b1-2) include the following.

  Y which is an aliphatic hydrocarbon group or a saturated cyclic hydrocarbon group substituted with a sulfonate anion or an aliphatic hydrocarbon group containing an unsubstituted Y and a divalent group represented by the formula (b1-3) Examples of the sulfonate anion containing the divalent group represented by the formula (b1-3) include the following.

  Examples of the sulfonate anion containing Y, which is a saturated cyclic hydrocarbon group substituted with an alkoxy group, and a divalent group represented by the formula (b1-3) include the following.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (b1-3) include the following: Things.

  Examples of the sulfonate anion containing Y having an oxo group and the divalent group represented by the formula (b1-3) include the following.

  Examples of the sulfonate anion containing Y, which is a saturated cyclic hydrocarbon group substituted with an aliphatic hydrocarbon group, and a divalent group represented by the formula (b1-4) include the following.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with an alkoxy group and a divalent group represented by the formula (b1-4) include the following.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (b1-4) include the following: Things.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group having an oxo group and a divalent group represented by the formula (b1-4) include the following.

Among these, the following sulfonate anions having a divalent group represented by the formula (b1-1) are more preferable.

  Examples of the cation contained in the acid generator (B) include an onium cation such as a sulfonium cation, an iodonium cation, an ammonium cation, a benzothiazolium cation, and a phosphonium cation. Among these, a sulfonium cation and an iodonium cation are preferable, and an arylsulfonium cation is more preferable.

Z ⁺ in formula (B1) is preferably represented by any of formula (b2-1) to formula (b2-4).

In formula (b2-1) to formula (b2-4),
R ^{b4 to} R ^b6 each independently represent a C _{1 to} C ₃₀ aliphatic hydrocarbon group, a C _{3 to} C ₃₆ saturated cyclic hydrocarbon group or a C _{6 to} C ₁₈ aromatic hydrocarbon group, hydrogen group, hydroxy group, may be substituted by C ₁ -C ₁₂ alkoxy or C ₆ -C ₁₈ aromatic hydrocarbon group, the saturated cyclic hydrocarbon group, a halogen atom, C ₂ -C ₄ acyl group or may be substituted by glycidyl group, the aromatic hydrocarbon group, a halogen atom, hydroxy group, C ₁ -C ₃₆ aliphatic hydrocarbon group, C ₃ -C ₃₆ saturated cyclic hydrocarbon group or a C _It may be substituted with a _{1 to} C ₁₂ alkoxy group.

R ^b7 and R ^b8 each independently represent a hydroxy group, a C _{1 to} C ₁₂ aliphatic hydrocarbon group or a C _{1 to} C ₁₂ alkoxy group.
m2 and n2 each independently represent an integer of 0 to 5.

R ^b9 and R ^b10 each independently represent a C _{1 to} C ₃₆ aliphatic hydrocarbon group or a C _{3 to} C ₃₆ saturated cyclic hydrocarbon group.
R ^b11 represents a hydrogen atom, a C _{1 to} C ₃₆ aliphatic hydrocarbon group, a C _{3 to} C ₃₆ saturated cyclic hydrocarbon group, or a C _{6 to} C ₁₈ aromatic hydrocarbon group.
The aliphatic hydrocarbon group for R ^{b9 to} R ^b11 is preferably C _{1 to} C ₁₂ , and the saturated cyclic hydrocarbon group is preferably C _{3 to} C ₃₆ , more preferably C _{4 to} C ₁₂ .
R ^b12 represents a C _{1 to} C ₁₂ aliphatic hydrocarbon group, a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group or a C _{6 to} C ₁₈ aromatic hydrocarbon group, and the aromatic hydrocarbon group is a C ₁ to C ₁₈ C ₁₂ aliphatic hydrocarbon group, C ₁ -C ₁₂ alkoxy group, C ₃ -C ₁₈ saturated cyclic hydrocarbon group or alkylcarbonyloxy group may be substituted.
R ^b9 and R ^b10 , and R ^b11 and R ^b12 may be independently bonded to each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring), These rings —CH ₂ — may be replaced by —O—, —S— or —CO—.

R ^{b13 to} R ^b18 each independently represents a hydroxy group, a C _{1 to} C ₁₂ aliphatic hydrocarbon group or a C _{1 to} C ₁₂ alkoxy group.
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 any of o2 to t2 is 2, any of the plurality of R ^{b13 to} R ^b18 may be the same as or different from each other.

  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.

Preferred aliphatic hydrocarbon groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl and 2-ethylhexyl. It is.
Preferred saturated cyclic hydrocarbon groups are cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyl-2-adamantyl group, 1- (1-adamantyl) -1-alkyl group, And an isobornyl group.
Preferred aromatic hydrocarbon groups are phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, biphenylyl group, naphthyl group. It is.
Examples of the aliphatic hydrocarbon group (aralkyl group) whose substituent is an aromatic hydrocarbon group include a benzyl group.
Examples of the ring formed by R ^b9 and R ^b10 include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring.
^Examples of the ring formed by R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferable, the cation represented by the formula (b2-1-1) is more preferable, and the triphenylsulfonium cation (formula (b2) In (1-1), v2 = w2 = x2 = 0) is more preferable.

式（ｂ２−１−１）中、
Ｒ^b19〜Ｒ^b21は、それぞれ独立に、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、Ｃ₁〜Ｃ₃₆脂肪族炭化水素基、Ｃ₃〜Ｃ₃₆飽和環状炭化水素基又はＣ₁〜Ｃ₁₂アルコキシ基を表す。
脂肪族炭化水素基は、好ましくはＣ_１〜Ｃ_１２であり、飽和環状炭化水素基は、好ましくはＣ_４〜Ｃ_３６である。
前記脂肪族炭化水素基は、ヒドロキシ基、Ｃ₁〜Ｃ₁₂アルコキシ基又はＣ₆〜Ｃ₁₈芳香族炭化水素基で置換されていてもよい。
前記飽和環状炭化水素基は、ハロゲン原子、Ｃ₂〜Ｃ₄アシル基又はグリシジルオキシ基で置換されていてもよい。
ｖ２〜ｘ２は、それぞれ独立に０〜５の整数（好ましくは０又は１）を表す。ｖ２〜ｘ２のいずれかが２以上のとき、それぞれ、複数のＲ^b19〜Ｒ^b21のいずれかは、互いに同一でも異なってもよい。

In formula (b2-1-1),
R ^{b19 to} R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, a C _{1 to} C ₃₆ aliphatic hydrocarbon group, a C _{3 to} C ₃₆ saturated cyclic hydrocarbon group, or a C _{1 to} C ₁₂ represents an alkoxy group.
The aliphatic hydrocarbon group is preferably C _{1 to} C ₁₂ , and the saturated cyclic hydrocarbon group is preferably C _{4 to} C ₃₆ .
The aliphatic hydrocarbon group, hydroxy group, may be substituted by C ₁ -C ₁₂ alkoxy or C ₆ -C ₁₈ aromatic hydrocarbon group.
The saturated cyclic hydrocarbon group may be substituted with a halogen atom, a C ₂ -C ₄ acyl group or a glycidyloxy group.
v2 to x2 each independently represents an integer of 0 to 5 (preferably 0 or 1). When any one of v2 to x2 is 2 or more, any one of the plurality of R ^{b19 to} R ^b21 may be the same as or different from each other.

Among these, R ^{b19 to} R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, a C _{1 to} C ₁₂ alkyl group, or a C _{1 to} C ₁₂ alkoxy group.

Specific examples of the cation (b2-1-1) include the following.

Specific examples of the cation (b2-2) include the following.

Specific examples of the cation (b2-3) include the following.

Specific examples of the cation (b2-4) include the following.

  The acid generator (B1) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned anion and cation can be arbitrarily combined, but any one of anion (b1-1-1) to anion (b1-1-9) and a cation (b2-1-1), and an anion ( A combination of any one of b1-1-3) to (b1-1-5) and a cation (b2-3) is preferable.

  Preferred acid generators (B1) are those represented by formula (B1-1) to formula (B1-17). Among them, acid generators (B1-1), (B1-2), (B1-6), (B1-11), (B1-12), (B1-13) and (B1-14) containing a triphenylsulfonium cation ) Is more preferable.

  The content of the acid generator (B) 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) with respect to 100 parts by mass of the resin (A). Part or less).

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The resist composition of the present invention suitably contains a basic compound (C).
The content of the basic compound (C) is preferably about 0.01 to 1% by mass based on the solid content of the resist composition.

  The basic compound (C) is preferably a basic nitrogen-containing organic compound (for example, an amine and a basic ammonium salt). The amine may be an aliphatic amine or an aromatic amine. As the aliphatic amine, any of primary amine, secondary amine and tertiary amine can be used. The aromatic amine may be any of an amino group bonded to an aromatic ring such as aniline and a heteroaromatic amine such as pyridine. Preferable basic compound (C) includes an aromatic amine represented by the formula (C2), particularly an aniline represented by the formula (C2-1).

式中、
Ａｒ^c1は、芳香族炭化水素基を表す。
Ｒ^c5及びＲ^c6は、それぞれ独立に、水素原子、脂肪族炭化水素基（好ましくはアルキル基又はシクロアルキル基）、飽和環状炭化水素基或いは芳香族炭化水素基を表す。但し前記脂肪族炭化水素基、前記飽和環状炭化水素基又は前記芳香族炭化水素基の水素原子は、ヒドロキシ基、アミノ基、又はＣ₁〜Ｃ₆アルコキシ基で置換されていてもよく、前記アミノ基は、Ｃ₁〜Ｃ₄アルキル基で置換されていてもよい。
前記脂肪族炭化水素基は、好ましくはＣ_１〜Ｃ_６程度であり、前記飽和環状炭化水素基は、好ましくはＣ_５〜Ｃ_１０程度であり、前記芳香族炭化水素基は、好ましくはＣ_６〜Ｃ_１０程度である。
Ｒ^c7は、脂肪族炭化水素基（好ましくはアルキル基又はシクロアルキル基）、アルコキシ基、飽和環状炭化水素基或いは芳香族炭化水素基を表す。但し脂肪族炭化水素基、アルコキシ基、飽和環状炭化水素基及び芳香族炭化水素基の水素原子は、上記と同様の置換基を有していてもよい。
ｍ３は０〜３の整数を表す。ｍ３が２以上のとき、複数のＲ^c7は、互いに同一でも異なってもよい。
Ｒ^c7の脂肪族炭化水素基、飽和環状炭化水素基及び芳香族炭化水素基の好ましい炭素数は、上記と同じであり、Ｒ^c7のアルコキシ基は、好ましくはＣ_１〜Ｃ_６程度である。

Where
Ar ^c1 represents an aromatic hydrocarbon group.
R ^c5 and R ^c6 each independently represent a hydrogen atom, an aliphatic hydrocarbon group (preferably an alkyl group or a cycloalkyl group), a saturated cyclic hydrocarbon group, or an aromatic hydrocarbon group. However the aliphatic hydrocarbon group, a hydrogen atom of the saturated cyclic hydrocarbon group or the aromatic hydrocarbon group, hydroxy group, amino group, or a C ₁ -C ₆ alkoxy group may be substituted with the amino group may be substituted by C ₁ -C ₄ alkyl group.
The aliphatic hydrocarbon group is preferably about C _{1 to} C ₆ , the saturated cyclic hydrocarbon group is preferably about C _{5 to} C ₁₀ , and the aromatic hydrocarbon group is preferably C ₆ it is a ~C about _10.
R ^c7 represents an aliphatic hydrocarbon group (preferably an alkyl group or a cycloalkyl group), an alkoxy group, a saturated cyclic hydrocarbon group, or an aromatic hydrocarbon group. However, the hydrogen atom of an aliphatic hydrocarbon group, an alkoxy group, a saturated cyclic hydrocarbon group, and an aromatic hydrocarbon group may have a substituent similar to the above.
m3 represents an integer of 0 to 3. When m3 is 2 or more, the plurality of R ^c7 may be the same as or different from each other.
Aliphatic hydrocarbon group R ^c7, preferable number of carbon atoms of the saturated cyclic hydrocarbon group and the aromatic hydrocarbon group are the same as above, an alkoxy group of R ^c7 is independently in, preferably about C ₁ -C _6.

Examples of the aromatic amine (C2) include 1-naphthylamine and 2-naphthylamine.
Examples of aniline (C2-1) include aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine and the like.
Of these, diisopropylaniline (particularly 2,6-diisopropylaniline) is preferable.

式中、
Ｒ^c8は、上記Ｒ^c7で説明したいずれかの基を表す。
Ｒ^c9、Ｒ^c10、Ｒ^c11〜Ｒ^c14、Ｒ^c16〜Ｒ^c19及びＲ^c22は、それぞれ独立に、Ｒ^c5及びＲ^c6で説明したいずれかの基を表す。
Ｒ^c20、Ｒ^c21、Ｒ^c23〜Ｒ^c28は、それぞれ独立に、Ｒ^c7で説明したいずれかの基を表す。
ｏ３〜ｕ３は、それぞれ独立に０〜３の整数を表す。ｏ３〜ｕ３のいずれかが２以上であるとき、それぞれ、複数のＲ^c20〜Ｒ^c28のいずれかは互いに同一でも異なってもよい。
Ｒ^c15は、脂肪族炭化水素基、飽和環状炭化水素基又はアルカノイル基を表す。
ｎ３は０〜８の整数を表す。ｎ３が２以上のとき、複数のＲ^c15は、互いに同一でも異なってもよい。
Ｒ^c15の脂肪族炭化水素基は、好ましくはＣ_１〜Ｃ_６程度であり、飽和環状炭化水素基は、好ましくはＣ_３〜Ｃ_６程度であり、アルカノイル基は、好ましくはＣ_２〜Ｃ_６程度である。
Ｌ^c1及びＬ^c2は、それぞれ独立に、２価の脂肪族炭化水素基（好ましくはアルキレン基）、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｃ（＝ＮＲ^c3）−、−Ｓ−、−Ｓ−Ｓ−又はこれらの組合せを表す。前記２価の脂肪族炭化水素基は、好ましくはＣ_１〜Ｃ_６程度である。
Ｒ^c3は、Ｃ₁〜Ｃ₄アルキル基を表す。 Examples of the basic compound (C) include compounds represented by the formulas (C3) to (C11).

Where
R ^c8 represents any of the groups described for R ^c7 above.
R ^c9 , R ^c10 , R ^{c11 to} R ^c14 , R ^{c16 to} R ^c19 and R ^c22 each independently represent any of the groups described for R ^c5 and R ^c6 .
R ^c20 , R ^c21 , R ^{c23 to} R ^c28 each independently represents any of the groups described for R ^c7 .
o3 to u3 each independently represents an integer of 0 to 3. When any of o3 to u3 is 2 or more, any of the plurality of R ^{c20 to} R ^c28 may be the same as or different from each other.
R ^c15 represents an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group or an alkanoyl group.
n3 represents an integer of 0 to 8. When n3 is 2 or more, the plurality of R ^c15 may be the same as or different from each other.
The aliphatic hydrocarbon group for R ^c15 is preferably about C _{1 to} C ₆ , the saturated cyclic hydrocarbon group is preferably about C _{3 to} C ₆ , and the alkanoyl group is preferably C _{2 to} C _6. Degree.
L ^c1 and L ^c2 are each independently a divalent aliphatic hydrocarbon group (preferably an alkylene group), —CO—, —C (═NH) —, —C (═NR ^c3 ) —, —S—. , -SS- or a combination thereof. The divalent aliphatic hydrocarbon group is preferably about C _{1 to} C ₆ .
R ^c3 represents a C ₁ -C ₄ alkyl group.

  Examples of the compound (C3) include hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, Tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctyl Amine, methyl dinonyl amine, methyl didecyl amine, ethyl dibutyl amine, ethyl dipentyl amine, ethyl di Silamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine ethylenediamine, tetramethylenediamine, hexamethylene Examples include diamine, 4,4′-diamino-1,2-diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and the like.

Examples of the compound (C4) include piperazine.
Examples of the compound (C5) include morpholine.
Examples of the compound (C6) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound (C7) include 2,2′-methylenebisaniline.
Examples of the compound (C8) include imidazole and 4-methylimidazole.
Examples of the compound (C9) include pyridine and 4-methylpyridine.
Examples of the compound (C10) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, and 1,2-di. (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide, 4, 4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine and the like can be mentioned.
Examples of the compound (C11) include bipyridine.

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

<Solvent (sometimes referred to as "solvent (E)")
The resist composition of the present invention may contain the solvent (E) in an amount of 90% by mass or more in the composition. The resist composition of the present invention containing the solvent (E) is suitable for producing a thin film resist. The content of the solvent (E) is 90% by mass or more (preferably 92% by mass or more, more preferably 94% by mass or more) and 99.9% by mass or less (preferably 99% by mass or less) in the composition.
The content of the solvent (E) can be measured by a known analysis means such as liquid chromatography or gas chromatography.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and And esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (E) may be used individually by 1 type, and may use 2 or more types together.

<Other components (hereinafter sometimes referred to as “other components (F)”)>
The resist composition of this invention may contain the other component (F) as needed. The component (F) is not particularly limited, and additives known in the resist field such as a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, a dye, and the like can be used.

<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 mentioned above on a board | substrate,
(2) a step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer using an exposure machine;
(4) A step of heating the composition layer after exposure,
(5) The process which develops the composition layer after a heating using a image development apparatus is included.

  Application of the resist composition onto the substrate can be performed by a commonly used apparatus such as a spin coater.

The removal of the solvent is performed, for example, by evaporating the solvent using a heating device such as a hot plate or by using a decompression device to form a composition layer from which the solvent has been removed. As for the temperature in this case, about 50-200 degreeC is illustrated, for example. The pressure is exemplified by about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is exposed using an exposure machine. The exposure machine may be an immersion exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. The exposure light source emits ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser, etc.) Various types of laser beam can be used, such as those that convert the wavelength of the laser beam from) to radiate a harmonic laser beam in the far ultraviolet region or the vacuum ultraviolet region.

The composition layer after the exposure is subjected to heat treatment for promoting the deprotection group reaction. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.
The heated composition layer is usually developed using an alkali developer using a developing device.
The alkaline developer used here 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).
After development, it is preferable to rinse with ultrapure water to remove water 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 EB or a resist composition for EUV exposure machines, and further for immersion exposure. It is suitable as a resist composition.

Hereinafter, the present invention will be described in detail by way of examples.
In Examples and Comparative Examples, “%” and “part” representing content and use amount are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by gel permeation chromatography (HLC-8120GPC type, manufactured by Tosoh Corporation, three columns are “TSKgel Multipore HXL-M”, and the solvent is tetrahydrofuran) using polystyrene as a standard product.
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 molar ratio of each structural unit of the polymer and the resin is determined by LC-IS method (LC-2010A manufactured by Shimadzu Corp., YMC-PAC manufactured by YMC Corp.). C4 column, solvent: acetonite, water), and each monomer was calculated by subtracting from the amount of monomer added first, by the molar ratio.

Resins were synthesized using the following monomers.

[Synthesis of Resin A1]
Monomer A, monomer B, monomer C, and monomer E were charged at a molar ratio of 40: 10: 40: 10, and 1.5 weight times dioxane of the total monomer amount was added to obtain a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a copolymer having a weight average molecular weight of 6.9 × 10 ^{3 in} a yield of 78%. . This copolymer has a structural unit of the following formula, and this is designated as resin A1. The molar ratio of each structural unit was A ′: B ′: C ′: E ′ = 31.9: 11.8: 45.7: 10.6.

[Synthesis of Resin A2]
Monomer D, monomer B, monomer C, and monomer E were charged at a molar ratio of 40: 10: 40: 10, and 1.5 times the total amount of dioxane was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a copolymer having a weight average molecular weight of 7.1 × 10 ^{3 in} a yield of 75%. . This copolymer has a structural unit of the following formula, and this is designated as resin A2. The molar ratio of each structural unit was D ′: B ′: C ′: E ′ = 29.8: 12.2: 46.5: 11.5.

[Synthesis of Resin A3]
Monomer F, monomer C and monomer E were charged in a molar ratio of 38:44:18, and then 1.5 mass times dioxane was added to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution is purified by pouring it into a large amount of methanol / water mixed solvent (5: 1) and precipitating three times, and the weight average molecular weight is about 7.2 × 10 ^3. The coalescence was obtained in 72% yield. This copolymer has a structural unit of the following formula, and this is designated as resin A3. The molar ratio of each structural unit was F ′: C ′: E ′ = 37.7: 44.4: 17.9.

[Synthesis of Resin A4]
Monomer A, Monomer H, Monomer J, Monomer C, Monomer I, and Monomer E are charged at a molar ratio of 35: 5: 5: 20: 30: 5, and 1.5 wt. did. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a copolymer having a weight average molecular weight of 7.1 × 10 ^{3 in} a yield of 69%. . This copolymer has a structural unit of the following formula, and this is designated as resin A4. The molar ratio of each structural unit is A ′: H ′: J ′: C ′: I ′: E ′ = 27.9: 5.4: 5.1: 22.5: 34.0: 5.1. there were.

[Synthesis of Resin A5]
Monomer D, monomer K, monomer B, monomer C, monomer I, and monomer G are charged at a molar ratio of 40: 5: 8: 20: 22: 5, and 1.5 wt. did. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a copolymer having a weight average molecular weight of 7.0 × 10 ^{3 in} a yield of 62%. . This copolymer has a structural unit of the following formula, and this is designated as resin A5. The molar ratio of each structural unit is D ′: K ′: B ′: C ′: I ′: G ′ = 29.7: 5.8: 9.2: 24.4: 25.2: 5.7. there were.

Examples and Comparative Examples As shown in Table 1, the above resin and the following components were mixed and dissolved, and the resulting mixture was filtered through a fluororesin filter having a pore size of 0.2 μm, thereby chemically amplified. A photoresist composition was prepared.

酸発生剤Ｂ２：

酸発生剤Ｂ３：トリフェニルスルホニウムノナフルオロブタンスルホネート <Acid generator>
Acid generator B1:

Acid generator B2:

Acid generator B3: triphenylsulfonium nonafluorobutanesulfonate

<Basic compound: Quencher>
Quencher C1: 2,6-diisopropylaniline <Solvent>
Propylene glycol monomethyl ether acetate 265 parts 2-heptanone 20.0 parts Propylene glycol monomethyl ether 20.0 parts γ-butyrolactone 3.5 parts

(Formation and evaluation of resist pattern)
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. On this organic antireflection film, the above resist composition was spin-coated so that the film thickness after drying was 85 nm.
The silicon wafer obtained by applying the resist composition was pre-baked (PB) for 60 seconds on a direct hot plate at the temperature described in the “PB” column of Table 1.
Using the ArF excimer stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light], the exposure amount is changed in stages on the obtained wafer. The andspace pattern was subjected to immersion exposure.
After the exposure, post-exposure baking (PEB) was performed on the hot plate at the temperature described in the “PEB” column of Table 1 for 60 seconds.
Further, paddle development was performed for 60 seconds with an aqueous 2.38 mass% tetramethylammonium hydroxide solution.

  In each resist film, the exposure amount at which the 50 nm line and space pattern becomes an exposure amount of 1: 1 was defined as the effective sensitivity.

Line edge roughness evaluation (LER): The surface of the resist pattern after the lithography process is observed with a scanning electron microscope, and the contact width of the unevenness on the side wall of the resist pattern is 5 nm or less. did.
These results are shown in Table 2.

  The resist composition of the present invention is particularly useful for a chemically amplified photoresist composition, and is used in a wide range of applications such as semiconductor microfabrication, production of circuit boards such as liquid crystal and thermal head, and other photofabrication processes. Can be suitably used. Since the line edge roughness (LER) of the resulting pattern can be further improved, it can be used as a chemically amplified photoresist composition suitable for excimer laser lithography such as ArF and KrF, ArF immersion exposure lithography, and EUV exposure lithography. it can. In addition to immersion exposure, it can also be used for dry exposure. Furthermore, it can be used for double imaging and is industrially useful.

Claims (7)

A resist composition comprising a resin having a structural unit derived from a compound represented by formula (I), an acid generator represented by formula (B1), and a basic compound.

[In the formula (I),
R ¹ represents a hydrogen atom, a halogen atom or a C ₁ -C ₆ alkyl group which may have a halogen atom.
R ² and R ³ each independently represent a hydrogen atom, a hydroxy group or a C _{1 to} C ₆ aliphatic hydrocarbon group.
n represents an integer of 1 to 6. ]

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C _{1 to} C ₆ perfluoroalkyl group.
L ^b1 represents a single bond or a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. Also good.
Y represents a C _{1 to} C ₁₈ aliphatic hydrocarbon group which may have a substituent or a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group which may have a substituent, and the aliphatic hydrocarbon —CH ₂ — contained in the group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ] The resist composition according to claim 1, wherein R ² and R ³ are hydrogen atoms. The resist composition according to claim 1, wherein at least one of R ² and R ³ is a hydroxy group.   The resin further has a structural unit derived from a monomer having an acid labile group, and is insoluble or hardly soluble in an alkaline aqueous solution, and the resin that has reacted with an acid is a resin that can be dissolved in an alkaline aqueous solution. The resist composition in any one of Claims 1-3. The resist composition according to claim 1, wherein L ^b1 is * —CO—O— (* represents a bond with —C (Q ¹ ) (Q ² ) —). The resist composition according to any one of claims 1 to 5, wherein Z ⁺ is an arylsulfonium cation. (1) The process of apply | coating the resist composition in any one of Claims 1-6 on a board | substrate,
(2) a step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer using an exposure machine;
(4) A step of heating the composition layer after exposure,
(5) A method for producing a resist pattern, comprising a step of developing the heated composition layer using a developing device.