JP2011253179A - Resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition which excels in a mask error factor (MEF) and a focus margin (DOF) in pattern forming.SOLUTION: A resist composition comprises: a polymer which has a group represented by formula (I) and a group represented by formula (II), and do not have an acid labile group; a resin which has an acid labile group, and is insoluble or hardly soluble in an alkali aqueous solution, and can dissolve in an alkali aqueous solution by an action of an acid; and an acid generator. (Rrepresents an a fluorinated alkyl group having 1-6 carbon atoms; Rrepresents an a fluorinated alkyl group having 1-6 carbon atoms; Rrepresents a hydrogen atom or a fluorinated alkyl group having 1-6 carbon atoms; and * represents a bond.)

Description

  The present invention relates to a resist composition.

A resist composition used for semiconductor microfabrication using a lithography technique contains an acid generator and a resin.
Patent Document 1 discloses a polymer composed of a structural unit derived from a compound represented by formula (J) and a structural unit derived from a compound represented by formula (P), and a compound represented by formula (M). A resin having a structural unit derived from the above, a structural unit derived from the compound represented by the formula (B), and a structural unit derived from the compound represented by the formula (O), and triphenylsulfonium perfluorobutane sulfonate A resist composition containing an acid generator is described.

JP 2009-191151 A

  In the conventional resist composition, the mask error factor (MEF) and focus margin (DOF) of the obtained pattern may not always be satisfied, or defects may occur.

［式（Ｉ）中、Ｒ^１は、炭素数１〜６のフッ化アルキル基を表す。＊は結合手を表す。］

［式（ＩＩ）中、Ｒ^２は、炭素数１〜６のフッ化アルキル基を表す。
Ｒ^３は、水素原子又は炭素数１〜６のフッ化アルキル基を表す。＊は結合手を表す。］ The present invention includes the following inventions.
[1] A polymer having a group represented by the formula (I) and a group represented by the formula (II), having no acid-labile group, and having an acid-labile group, A resist composition comprising a resin that is insoluble or hardly soluble in an alkaline aqueous solution and that can be dissolved in an alkaline aqueous solution by the action of an acid, and an acid generator.

[In Formula (I), R ¹ represents a fluorinated alkyl group having 1 to 6 carbon atoms. * Represents a bond. ]

[In Formula (II), R ² represents a fluorinated alkyl group having 1 to 6 carbon atoms.
R ³ represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms. * Represents a bond. ]

［式（Ｉ−１）中、Ｒ^１は、上記と同じ意味を表す。
Ｒ^４は、水素原子又はメチル基を表す。
Ａ^１は、２価の炭素数１〜１２の飽和炭化水素基を表す。］ [2] The resist composition according to [1], wherein the polymer is a polymer having a structural unit derived from the compound represented by formula (I-1).

[In formula (I-1), R ¹ represents the same meaning as described above.
R ⁴ represents a hydrogen atom or a methyl group.
A ¹ represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. ]

［式（ＩＩ−１）中、Ｒ^２及びＲ^３は、上記と同じ意味を表す。
Ｒ^５は、水素原子又はメチル基を表す。
Ｂ^１は、２価の炭素数１〜１０の飽和炭化水素基を表す。］ [3] The resist composition according to [1] or [2], wherein the polymer is a polymer having a structural unit derived from the compound represented by the formula (II-1).

[In formula (II-1), R ² and R ³ represent the same meaning as described above.
R ⁵ represents a hydrogen atom or a methyl group.
B ¹ represents a divalent saturated hydrocarbon group having 1 to 10 carbon atoms. ]

［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、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−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炭素数１〜１８の脂肪族炭化水素基又は置換基を有していてもよい炭素数３〜１８の飽和環状炭化水素基を表し、該脂肪族炭化水素基及び該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。］
〔５〕 さらに塩基性化合物を含む〔１〕〜〔４〕のいずれか記載のレジスト組成物。 [4] The resist composition according to any one of [1] to [3], wherein the acid generator 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 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. May be.
Y represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent or a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the aliphatic group —CH ₂ — contained in the hydrocarbon group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]
[5] The resist composition according to any one of [1] to [4], further containing a basic compound.

[6] (1) A step of applying the resist composition according to any one of [1] to [5] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer using an exposure machine;
(4) A step of heating the composition layer after exposure,
(5) a step of developing the heated composition layer using a developing device;
A method for producing a resist pattern including:

  The resist composition of the present invention is excellent in mask error factor (MEF) and focus margin (DOF) when forming a resist pattern. Moreover, according to the resist composition of this invention, a pattern with few defects can be formed.

  The resist composition of the present invention includes a polymer having a group represented by the formula (I) and a group represented by the formula (II) and having no acid-labile group, and an acid-labile group. A resin having a group and insoluble or hardly soluble in an alkaline aqueous solution and capable of being dissolved in an alkaline aqueous solution by the action of an acid; and an acid generator.

<Polymer having group represented by formula (I) and group represented by formula (II) and having no acid-labile group>
The polymer has a group represented by the formula (I) and a group represented by the formula (II), and does not have an acid-labile group.

［式（Ｉ）中、Ｒ^１は、炭素数１〜６のフッ化アルキル基を表す。＊は結合手を表す。］

［式（ＩＩ）中、Ｒ^２は、炭素数１〜６のフッ化アルキル基を表す。
Ｒ^３は、水素原子又は炭素数１〜６のフッ化アルキル基を表す。＊は結合手を表す。］

[In Formula (I), R ¹ represents a fluorinated alkyl group having 1 to 6 carbon atoms. * Represents a bond. ]

[In Formula (II), R ² represents a fluorinated alkyl group having 1 to 6 carbon atoms.
R ³ represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms. * Represents a bond. ]

  Examples of the fluorinated alkyl group having 1 to 6 carbon atoms include difluoromethyl group, perfluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, Fluoroethyl 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- (perfluoropropylene ) 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, Examples include perfluoropentylmethyl group and perfluorohexyl group.

R ¹ is preferably a fluorinated alkyl group having 1 to 4 carbon atoms, more preferably a perfluoromethyl group, a perfluoroethyl group or a perfluoropropyl group, and still more preferably a perfluoromethyl group. .

R ² is preferably a fluorinated alkyl group having 1 to 5 carbon atoms when R ³ is a fluorinated alkyl group having 1 to 4 carbon atoms, more preferably a perfluoromethyl group, a perfluoroethyl group or a perfluoroalkyl group. A fluoropropyl group, more preferably a perfluoromethyl group.
When R ³ is a hydrogen atom, R ² is preferably a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a fluorinated alkyl group having 3 to 5 carbon atoms, still more preferably 5 carbon atoms. A fluorinated alkyl group, particularly preferably a (CF ₃ ) ₂ CF—CF ₂ —CH ₂ — group.

R ³ is preferably a hydrogen atom or a fluorinated alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a perfluoromethyl group, a perfluoroethyl group or a perfluoropropyl group, still more preferably A hydrogen atom or a perfluoromethyl group.

The polymer preferably has a structural unit derived from a compound containing a group represented by the formula (I).
More preferably, the polymer has a structural unit derived from a compound containing a group represented by the formula (I) and a carbon-carbon double bond.

［式（ＩＩＩ）中、Ｒ^６、Ｒ^７及びＲ^８は、それぞれ独立に、水素原子、炭素数１〜１０のアルキル基、ヒドロキシメチル基、トリフルオロメチル基又はフェニル基を表す。＊は、結合手を表す。］
アルキル基としては、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基が挙げられる。 The group containing a carbon-carbon double bond is represented by, for example, formula (III).

[In the formula (III), R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxymethyl group, a trifluoromethyl group or a phenyl group. * Represents a bond. ]
Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, and decyl group.

R ⁶ and R ⁸ are preferably a hydrogen atom, and R ⁷ is preferably a hydrogen atom or a methyl group.

［式（Ｉ−１）中、Ｒ^１は、上記と同じ意味を表す。
Ｒ^４は、水素原子又はメチル基を表す。
Ａ^１は、２価の炭素数１〜１２の飽和炭化水素基を表す。］ Examples of the compound containing a group represented by the formula (I) and a carbon-carbon double bond include a compound represented by the formula (I-1).

[In formula (I-1), R ¹ represents the same meaning as described above.
R ⁴ represents a hydrogen atom or a methyl group.
A ¹ represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. ]

  Examples of the divalent saturated hydrocarbon group having 1 to 12 carbon atoms include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, and 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- Directly such as diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group, etc. A linear alkanediyl group; a linear alkanediyl group and an alkyl group having 1 to 4 carbon atoms (for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, etc.) With added side chains For example, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1, Branched alkanediyl groups such as 4-diyl group; cyclobutane-1,3-diyl group, 1,3-cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group silene group, cyclooctane- Monocyclic divalent saturated cyclic hydrocarbon group such as 1,5-diyl group; norbornane-1,4-diyl group, norbornane-2,5-diyl group, 1,5-adamantane-1,5-diyl And a polycyclic divalent saturated cyclic hydrocarbon group such as an adamantane-2,6-diyl group. Moreover, what combined 2 or more types of these groups may be used.

Examples of the compound containing a group represented by the formula (I) include the following compounds.

  The content of the structural unit derived from the compound containing the group represented by the formula (I) is usually 30 to 95 mol%, preferably 40 to 90 mol%, based on all the structural units of the polymer. More preferably, it is 50-80 mol%, More preferably, it is 60-80 mol%. When the content of the structural unit derived from the compound containing the group represented by the formula (I) is within the above range, the focus margin (DOF) at the time of pattern formation is particularly wide, and the obtained pattern has few defects. This is preferable because there is a tendency.

The polymer preferably has a structural unit derived from a compound containing a group represented by the formula (II).
More preferably, the polymer has a structural unit derived from a compound containing a group represented by formula (II) and a carbon-carbon double bond.

［式（ＩＩ−１）中、Ｒ^２及びＲ^３は、上記と同じ意味を表す。
Ｒ^５は、水素原子又はメチル基を表す。
Ｂ^１は、２価の炭素数１〜１０の飽和炭化水素基を表す。］ Examples of the compound containing a group represented by the formula (II) and a carbon-carbon double bond include a compound represented by the formula (II-1).

[In formula (II-1), R ² and R ³ represent the same meaning as described above.
R ⁵ represents a hydrogen atom or a methyl group.
B ¹ represents a divalent saturated hydrocarbon group having 1 to 10 carbon atoms. ]

  As a bivalent C1-C10 saturated hydrocarbon group, a C1-C10 thing is mentioned among the groups quoted above.

Examples of the compound containing a group represented by the formula (II) include the following compounds.

  The content of the structural unit derived from the compound containing the group represented by the formula (II) is usually 5 to 70 mol%, preferably 10 to 60 mol%, based on all the structural units of the polymer. More preferably, it is 10-50 mol%, More preferably, it is 20-40 mol%. When the content of the structural unit derived from the compound containing the group represented by the formula (II) is within the above range, the focus margin (DOF) at the time of pattern formation is wide, and the obtained pattern has few defects. This is preferable because there is a tendency.

The polymer does not have an acid-labile group described later.
The polymer can be produced by a method known in the art. For example, it can be produced by the method described in JP 2010-1461 A.
For example, it can be obtained by reacting the monomer constituting the polymer in a solvent using a polymerization initiator. Examples of the solvent include 1,4-dioxane. Examples of the polymerization initiator include azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile).

The weight average molecular weight of the polymer is preferably 8,000 or more (more preferably 10,000 or more) and 80,000 or less (more preferably 60,000 or less).
A polymer is 0.1-10 mass% normally in solid content of a composition, Preferably it is 0.3-5 mass%, More preferably, it is 0.5-3 mass%.
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 polymer relative thereto can be measured by a known analytical means such as liquid chromatography or gas chromatography, for example.

<Resin having an acid labile group and insoluble or hardly soluble in an alkaline aqueous solution and soluble in an alkaline aqueous solution by the action of an acid (hereinafter sometimes referred to as “resin (A)”)>
Resin (A) is a resin that becomes alkali-soluble by the action of an acid. A resin that becomes alkali-soluble by the action of an acid can be produced by polymerizing a monomer having an acid-labile group (hereinafter sometimes referred to as “monomer having an acid-labile group (a1)”), It becomes alkali-soluble 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. 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、炭素数１〜８の脂肪族炭化水素基又は炭素数３〜２０の飽和環状炭化水素基を表すか或いはＲ^a1及びＲ^a2は互いに結合して炭素数３〜２０の環を形成する。＊は結合手を表す（以下同じ）。

In the formula (1), R ^{a1 to} R ^a3 each independently represent an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 20 carbon atoms, or R ^a1 and R ^a2 are Bond to each other to form a ring having 3 to 20 carbon atoms. * Represents a bond (same below).

式（１）における飽和環状炭化水素基の炭素数は、好ましくは炭素数３〜１６である。 Examples of the aliphatic hydrocarbon group include an alkyl group, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The saturated cyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic saturated cyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and dimethylcyclohexyl. Cycloalkyl groups such as a group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic saturated hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, a methylnorbornyl group, and the following groups.

Carbon number of the saturated cyclic hydrocarbon group in Formula (1) becomes like this. Preferably it is C3-C16.

When R ^a1 and R ^a2 are bonded to each other to form a ring, examples of the —C (R ^a1 ) (R ^a2 ) (R ^a3 ) group include the following groups. The number of carbon atoms in the ring is preferably 3 to 12 carbon atoms.

Examples of the acid labile group (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), groups in which R ^{a1 to} R ^a3 are alkyl groups, preferably a tert-butoxycarbonyl group), 2-alkyladamantan-2-yloxycarbonyl 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- (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).

  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 Here, (meth) acryl represents acryl and / or methacryl.

  Among the (meth) acrylic monomers having the acid-labile group (1), those having a saturated cyclic hydrocarbon group having 5 to 20 carbon atoms are preferred. Further, among the monomers (a1) having an acid labile group, if a resin obtained by polymerizing a monomer having a bulky structure such as a saturated cyclic hydrocarbon group is used, the resolution of the resist can be improved. Can do.

  Among (meth) acrylic monomers having an acid labile group (1) and a saturated cyclic hydrocarbon group, a monomer represented by the formula (a1-1) and a monomer represented by the formula (a1-2) Is 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−を表す。
ｋ１は１〜７の整数を表す。＊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の脂肪族炭化水素基又は炭素数３〜１０の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—.
k1 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10. ]

ｍ１は、好ましくは０〜３の整数、より好ましくは０又は１である。
ｎ１は、好ましくは０〜３の整数、より好ましくは０又は１である。 L ^a1 and L ^a2 are preferably —O— or ^* —O— (CH ₂ ) _f1 —CO—O— (wherein f1 represents an integer of 1 to 4), more preferably —O—. It is. k1 is preferably an integer of 1 to 4, more preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the aliphatic hydrocarbon group for R ^a6 and R ^a7 include an alkyl group, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. The aliphatic hydrocarbon group represented by R ^a6 and R ^a7 preferably has 6 or less carbon atoms. The saturated cyclic hydrocarbon group preferably has 8 or less carbon atoms, more preferably 6 or less.
The saturated cyclic hydrocarbon group for R ^a6 and R ^a7 may be either monocyclic or polycyclic. Examples of the monocyclic saturated cyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, and a methylcyclohexyl group. Cycloalkyl groups such as a group, dimethylcyclohexyl group, cycloheptyl group, and cyclooctyl group. Examples of the polycyclic saturated hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, methylnorbornyl group, and the following groups.

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.

  Examples of the monomer represented by the formula (a1-1) include the following. Among them, 2-methyladamantan-2-yl (meth) acrylate, 2-ethyladamantan-2-yl (meth) acrylate and 2-isopropyladamantan-2-yl (meth) acrylate are preferable, and 2-methyladamantan-2-yl Il methacrylate, 2-ethyladamantan-2-yl methacrylate and 2-isopropyladamantan-2-yl methacrylate are more preferred.

  Examples of the monomer represented by the formula (a1-2) include the following. Among these, 1-ethylcyclohexane-1-yl (meth) acrylate is preferable, and 1-ethylcyclohexane-1-yl methacrylate is more preferable.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a1-1) and / or a structural unit derived from the monomer represented by the formula (a1-2), the total content thereof is , Usually 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, still more preferably 30 to 60 mol, based on all structural units of the resin (A). %.

  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 represented by the formula (a1-3) has a bulky structure, the resolution of the resist can be improved. Furthermore, the monomer represented by the formula (a1-3) can improve the dry etching resistance of the 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、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、シアノ基又は炭素数１〜８のアルコキシカルボニル基（−ＣＯＯＲ^a13）を表し、Ｒ^a13は、炭素数１〜８の脂肪族炭化水素基又は炭素数３〜２０の飽和環状炭化水素基を表し、該脂肪族炭化水素基及び該飽和環状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飽和環状炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｒ^a10〜Ｒ^a12は、それぞれ独立に、炭素数１〜１２の脂肪族炭化水素基又は炭素数３〜２０の飽和環状炭化水素基を表すか、或いはＲ^a10及びＲ^a11は互いに結合して炭素数３〜２０の環を形成し、該脂肪族炭化水素基及び該飽和環状炭化水素基に含まれる水素原子はヒドロキシ基等で置換されていてもよく、該脂肪族炭化水素基及び該飽和環状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。］

[In the formula (a1-3),
R ^a9 represents a hydrogen atom, a C 1-3 aliphatic hydrocarbon group that may have a hydroxy group, a carboxy group, a cyano group, or a C 1-8 alkoxycarbonyl group (—COOR ^a13 ). , R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 20 carbon atoms, and the hydrogen atoms contained in the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group are It may be substituted with a hydroxy group, and —CH ₂ — contained in the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be replaced with —O— or —CO—.
R ^{a10 to} R ^a12 each independently represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 20 carbon atoms, or R ^a10 and R ^a11 are bonded to each other to form carbon. A hydrogen atom contained in the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group that forms a ring of several 3 to 20 may be substituted with a hydroxy group, etc., and the aliphatic hydrocarbon group and the saturated cyclic group —CH ₂ — contained in the hydrocarbon group may be replaced by —O— or —CO—. ]

  Here, examples of the alkoxycarbonyl group include groups in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group or 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 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 represented by the formula (a1-3) include, for example, 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene- 1-methylcyclohexyl 2-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, 1- (1-adamantyl) 5-norbornene-2-carboxylate And 1-methyl-ethyl.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a1-3), the content thereof is usually 10 to 95 mol% with respect to all the structural units of the resin (A). , Preferably it is 15-90 mol%, More preferably, it is 20-85 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炭素数１〜６のアルキル基を表す。
Ｒ¹¹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、水素原子又は炭素数１〜１２の炭化水素基を表す。
Ｘ^ａ２は、単結合又は２価の炭素数１〜１７の飽和炭化水素基を表し、該飽和炭化水素基に含まれるに含まれる水素原子はハロゲン原子、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のアシル基又は炭素数２〜４のアシルオキシ基で置換されていてもよく、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、水素原子又は炭素数１〜６のアルキル基を表す。
Ｙ^ａ３は、炭素数１〜１２の脂肪族炭化水素基、炭素数３〜１８の飽和環状炭化水素基又は炭素数６〜１８の芳香族炭化水素基であり、該脂肪族炭化水素基、該飽和環状炭化水素基及び該芳香族炭化水素基に含まれるに含まれる水素原子はハロゲン原子、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のアシル基又は炭素数２〜４のアシルオキシ基で置換されていてもよい。］ Examples of the monomer having an acid labile group (1) and a carbon-carbon double bond include monomers represented by the formula (a1-4).

[In the formula (a1-4),
R ¹⁰ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ¹¹ 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 acryloyl group, or methacryloyl. 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 represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
X ^a2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group is a halogen atom, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms. Group, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyloxy group having 2 to 4 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group is — CO—, —O—, —S—, —SO ₂ — or —N (R ^c ) — may be substituted. R ^c represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Y ^a3 is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, the aliphatic hydrocarbon group, The hydrogen atom contained in the saturated cyclic hydrocarbon group and the aromatic hydrocarbon group 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, or 2 to 4 carbon atoms. Or an acyloxy group having 2 to 4 carbon atoms. ]

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 an acetyl group, a propionyl group, and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
Examples of the hydrocarbon group include an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group, and an aromatic hydrocarbon group.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, anthryl groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.

The alkyl group for R ¹⁰ and R ¹¹ preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably a methyl group.
As the alkoxy group for R ¹¹ , C 1 or 2 is 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-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) -1-alkyl group, an isobornyl group, and the like are preferable.
The substituent that X ^a2 and Y ^a3 may have is preferably a hydroxy group.

  Examples of the monomer represented by the formula (a1-4) include the following monomers.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a1-4), the content is usually 10 to 95 mol% with respect to all the structural units of the resin (A). , Preferably it is 15-90 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 monomers represented by the formula (a1-5).

Examples of the monomer represented by the formula (a1-5) include the following monomers.

[In the formula (a1-5), R ³¹ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
Z ¹ represents a single bond or a * — (CH ₂ ) _s3 —CO—L ⁴ — group.
L ¹ , L ² , L ³ and L ⁴ each independently represent —O— or —S—.
s1 represents an integer of 1 to 3.
s2 represents an integer of 0 to 3.
s3 represents an integer of 1 to 4.
* Represents a bond to ^{L 1.} ]

  Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.

  Examples of the alkyl group having 1 to 6 carbon atoms 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 heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group and the like.

  Examples of the alkyl group having 1 to 6 carbon atoms 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, and a perfluorotert-butyl group. Group, perfluoropentyl group, perfluorohexyl group and the like.

R ³¹ is preferably a hydrogen atom or a methyl group.
L ¹ , L ² and L ⁴ are preferably —O—.
L ³ is preferably -S-.
s1 is preferably 1.
It is preferable that s2 is an integer of 0-2.
Z ¹ is preferably a single bond.

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

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a1-5), the content thereof is usually 1 to 30 mol% with respect to all the structural units of the resin (A). , Preferably 3 to 20 mol%, more preferably 5 to 10 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) or irradiation with high energy rays such as an electron beam or EUV light, a phenolic hydroxy group which is a hydroxystyrene is used as the acid-stable monomer (a2) having a hydroxy group. It is preferable to use an acid-stable monomer (a2-0) having 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.

  Examples of the monomer (a2-0) having a phenolic hydroxy group include styrene monomers such as p- or m-hydroxystyrene represented by the formula (a2-0).

［式（ａ２−０）中、
Ｒ^８１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^８２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。］

[In the formula (a2-0),
R ⁸¹ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
^R82 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 acryloyl group, or methacryloyl. Represents a 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. ]

^Examples of the alkyl group in R ⁸¹ and R ⁸² 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. Can be mentioned. R ⁸¹ is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 or 2 carbon atoms, and particularly preferably a methyl group.
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-pentyloxy group, and an n-hexyloxy group. An alkoxy group having 1 to 4 carbon atoms is preferable, an alkoxy group having 1 or 2 carbon atoms is more preferable, and a methoxy group is particularly preferable.
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 hydroxy group, radical polymerization of the corresponding (meth) acrylic acid ester monomer, acetoxystyrene, and styrene is followed by deacetylation with an acid. Can be obtained.
Examples of the monomer having a phenolic hydroxy group include the following monomers.

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

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a2-0), the content is usually 5 to 90 mol% with respect to all the structural units of the resin (A). , Preferably it is 10-85 mol%, More preferably, it is 15-80 mol%.

  Examples of the acid stable monomer having a hydroxyadamantyl group include a monomer represented by the formula (a2-1).

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。＊は−ＣＯ−との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。

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

In 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-hydroxyadamantan-1-yl (meth) acrylate, 3,5-dihydroxyadamantan-1-yl (meth) acrylate and (meth) acrylic acid 1- (3,5-dihydroxyadamantan-1-yloxycarbonyl ) Methyl is preferred, 3-hydroxyadamantan-1-yl (meth) acrylate and 3,5-dihydroxyadamantan-1-yl (meth) acrylate are more preferred, 3-hydroxyadamantan-1-yl methacrylate and 3,5- More preferred is dihydroxyadamantan-1-yl methacrylate.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a2-1), the content is usually 3 to 40 mol% with respect to all the structural units of the resin (A). , Preferably it is 5-35 mol%, More preferably, it is 5-30 mol%, More preferably, it is 5-15 mol%.

<Acid-stable monomer having a lactone ring (a3)>
The lactone ring possessed by the acid stable monomer (a3) may be, for example, a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, and a monocyclic lactone ring and other rings 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。＊は−ＣＯ−との結合手を表す。
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、炭素数１〜４の脂肪族炭化水素基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a22及びＲ^a23は、それぞれ独立に、カルボキシ基、シアノ基又は炭素数１〜４の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. * Represents a bond with -CO-.
R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
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.

Examples of L ^{a4 to} L ^{a6 in} formula (a3-1) to formula (a3-3) include those described for L ^a3 .
L ^{a4 to} L ^a6 are each independently preferably —O— or ^* —O— (CH ₂ ) _d1 —CO—O— (the d1 is an integer of 1 to 4), more preferably. Is —O—.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are 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.

  Among the acid stable monomers (a3-1) having a γ-butyrolactone ring, examples of the monomer having an acid labile group 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.

  Among the acid stable monomers (a3-2) having a condensed ring of γ-butyrolactone ring and norbornane ring, examples of the monomer having an acid labile group 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 monomers (a3-3) having a condensed ring of γ-butyrolactone ring and cyclohexane ring, examples of the monomer having an acid labile group 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.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a3-1), the formula (a3-2) and / or the formula (a3-3), the content of the resin (A) Is usually 5 to 50 mol%, preferably 10 to 45 mol%, more preferably 15 to 40 mol%, respectively. When the resin (A) includes a structural unit derived from the acid-stable monomer (a3) having a lactone ring, the total content is usually 5 to 60 mol% with respect to all the structural units of the resin (A). , Preferably 15 to 55 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、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、シアノ基、カルボキシ基又はアルコキシカルボニル基（−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、炭素数１〜１８の脂肪族炭化水素基又は炭素数３〜１８の飽和環状炭化水素基を表し、該脂肪族炭化水素基及び該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、第三級炭素原子が−Ｏ−と結合するものを含まない）。

In formula (a4-3),
R ^a25 and R ^a26 each independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxy group, a cyano group, a carboxy group or an alkoxycarbonyl group (—COOR ^a27 ). R ^a25 and R ^a26 combine with each other to form —CO—O—CO—,
R ^a27 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, and —CH ₂ — of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group is -O- or -CO- may be substituted. 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 hydroxyl group 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 preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms. The saturated cyclic hydrocarbon group preferably has 4 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.
^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.

  When resin contains the structural unit derived from the monomer represented by Formula (a4-1), Formula (a4-2), and Formula (a4-3), these total content is the whole structure of resin (A) It is 2-40 mol% normally with respect to a unit, Preferably it is 3-30 mol%, More preferably, it is 5-20 mol%.

［式（ａ４−４）中、
Ｌ^a７は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k５−ＣＯ−Ｏ−を表し、
ｋ５は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a２８は、水素原子又はメチル基を表す。
Ｗ¹は、置換基を有していてもよいスルトン環を表す。］ Furthermore, examples of the other acid stable monomer (a4) include the following acid stable monomers having a sultone ring represented by the formula (a4-4).

[In the formula (a4-4),
L ^a7 represents —O— or ^* —O— (CH ₂ ) _k5 —CO—O—,
k5 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a28 represents a hydrogen atom or a methyl group.
W ¹ represents a sultone ring which may have a substituent. ]

スルトン環が有していてもよい置換基としては、ヒドロキシ基、シアノ基、炭素数１〜６のアルキル基、炭素数１〜６のフッ素化アルキル基、炭素数１〜６のヒドロキシアルキル基、炭素数１〜６のアルコキシ基、炭素数１〜７のアルコキシカルボニル基、炭素数１〜７のアシル基、炭素数１〜８のアシルオキシ基が挙げられる。 The following ring is mentioned as a sultone ring.

As the substituent that the sultone ring may have, a hydroxy group, a cyano group, an alkyl group having 1 to 6 carbon atoms, a fluorinated alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, Examples thereof include an alkoxy group having 1 to 6 carbon atoms, an alkoxycarbonyl group having 1 to 7 carbon atoms, an acyl group having 1 to 7 carbon atoms, and an acyloxy group having 1 to 8 carbon atoms.

  When the resin (A) includes a structural unit derived from the compound represented by the formula (a4-4), the content is usually 2 to 40 mol% with respect to all the structural units of the resin (A). , Preferably it is 3-35 mol%, More preferably, it is 5-30 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 composed of the monomer (a1-1) having an adamantyl group and the monomer (a1-2) having a cyclohexyl group. The acid-stable monomer (a2) having a hydroxy group is preferably an acid-stable monomer (a2-1) having a hydroxyadamantyl group (more preferably, the monomer (a1-1) having an adamantyl group). The acid-stable monomer (a3) having a lactone ring is more preferably an acid-stable monomer (a3-1) having a γ-butyrolactone ring and an acid-stable monomer having a condensed ring of a γ-butyrolactone ring and a norbornane ring It is at least one selected from the group consisting of (a3-2). 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, more preferably 3,500 or more), 50,000 or less (more preferably 30,000 or less, and further preferably Is 10,000 or less).
It is preferable that content of resin (A) is 80 to 99 mass% 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.

<Acid generator (hereinafter sometimes referred to as "acid generator (B)")>
The acid generator (B) is classified into a nonionic type and an ionic type. Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonates), sulfones (e.g. disulfone, ketosulfone, sulfonyldiazomethane) and the like. The ionic acid generator is typically an onium salt containing an onium cation (for example, diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator (B) include not only an acid generator (particularly a photoacid generator) used in the resist field, but also a photoinitiator for photocationic polymerization, a photodecolorant for dyes, or a photochromic agent. Known compounds that generate an acid by radiation (light) and mixtures thereof can also be used as appropriate. For example, JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A 62-153853, Acid can be obtained by radiation described in Japanese Utility Model Laid-Open No. 63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. The resulting compound can be used.

  The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a sulfonate represented by the formula (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、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−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炭素数１〜１８の脂肪族炭化水素基又は置換基を有していてもよい炭素数３〜１８の飽和環状炭化水素基を表し、該脂肪族炭化水素基及び該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。］

[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 single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. May be.
Y represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent or a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the aliphatic group —CH ₂ — contained in the hydrocarbon 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 linear alkanediyl groups, branched alkanediyl groups, monocyclic and polycyclic divalent saturated cyclic hydrocarbon groups, and two of these groups. A combination of the above may also be used.
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 alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group;
On the side of an alkyl group (particularly an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group) Having a chain, for example, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, Branched alkanediyl groups such as 2-methylbutane-1,4-diyl group;
Cycloalkanediyl groups such as cyclobutane-1,3-diyl group, 1,3-cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group silene group, cyclooctane-1,5-diyl group, etc. A monocyclic divalent saturated cyclic hydrocarbon group which is
Polycyclic divalent saturated ring such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, 1,5-adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. A hydrocarbon group etc. are mentioned.

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group in L ^b1 is replaced by —O— or —CO— include formulas (b1-1) to (b1-6). It is done. 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、単結合又は炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２の２価の飽和炭化水素基を表す。
Ｌ^b4は、炭素数１〜１３の２価の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、炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b6及びＬ^b7は、それぞれ独立に、炭素数１〜１５の２価の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、炭素数１〜１４の２価の飽和炭化水素基を表す。
Ｌ^b9及びＬ^b10は、それぞれ独立に、炭素数１〜１１の２価の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。
中でも、式（ｂ１−１）で表される２価の基が好ましく、Ｌ^b2が単結合又は−ＣＨ_２−である式（ｂ１−１）で表される２価の基がより好ましい。

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

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, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, and a glycidyloxy group. Is mentioned.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, naphthylethyl group and the like.

As the aliphatic hydrocarbon group for Y, an alkyl group having 1 to 6 carbon atoms 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, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, and a hydroxy group. C1-C12 aliphatic hydrocarbon group, C3-C16 saturated cyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 aromatic hydrocarbon group, C7-C21 An aralkyl group, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group, or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an aliphatic hydrocarbon group having 1 to 16 carbon atoms) Represents a saturated cyclic hydrocarbon group having 3 to 16 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 represents an integer of 0 to 4). 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 that 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 substituted by — (CH ₂ ) _j2 —O—CO—R ^b1 group 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 the following formulas (b1-1-1) to (b1-1-9) in which the substituent L ^b1 is the formula (b1-1). An anion represented by 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 an aliphatic hydrocarbon group having 1 to 4 carbon atoms (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 sultone ring and the 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 a cation represented by any one of formula (b2-1) to formula (b2-4).

In these formulas (b2-1) to (b2-4),
R ^{b4 to} R ^b6 each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the saturated cyclic hydrocarbon group The hydrogen atom contained in may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group, and the aromatic hydrocarbon group may be a halogen atom, a hydroxy group, or a C 1-18 carbon atom. It may be substituted with an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.

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

R ^b9 and R ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 18 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms.
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
The aliphatic hydrocarbon group of R ^{b9 to} R ^b11 preferably has 1 to 12 carbon atoms, and the saturated cyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The aromatic hydrocarbon group is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkylcarbonyloxy having 1 to 12 carbon atoms. It may be substituted with a group.
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 represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^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 an integer of 2 or more, the plurality of R ^b13 are the same or different from each other, and when p2 is an integer of 2 or more, the plurality of R ^b14 are the same or different from each other, and s2 is an integer of 2 or more In this case, the plurality of R ^b17 are the same or different from each other, and when u2 is an integer of 2 or more, the plurality of R ^b18 are the same or different from each other. When q2 is an integer of 2 or more, the plurality of R ^b15 are the same or different from each other. When r2 is an integer of 2 or more, the plurality of R ^b16 are the same 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.

Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, 1-methylethyl group (isopropyl group), n-butyl group, 1,1-dimethylethyl group (tert-butyl group), 2, 2-dimethylethyl 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, Examples thereof include alkyl groups such as nonyl group, decyl group, undecyl group, and dodecyl group. Among them, preferred aliphatic hydrocarbon groups are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2- An ethylhexyl group.
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、炭素数１〜１８の脂肪族炭化水素基、炭素数３〜１８の飽和環状炭化水素基又は炭素数１〜１２のアルコキシ基を表す。
脂肪族炭化水素基は、好ましくは炭素数１〜１２であり、飽和環状炭化水素基は、好ましくは炭素数４〜１８である。
前記脂肪族炭化水素基は、ヒドロキシ基、炭素数１〜１２のアルコキシ基又は炭素数６〜１８の芳香族炭化水素基で置換されていてもよい。
前記飽和環状炭化水素基は、ハロゲン原子、炭素数２〜４のアシル基又はグリシジルオキシ基で置換されていてもよい。
ｖ２、ｗ２及び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が２以上の整数である場合、複数のＲ^b19は互いに同一か相異なり、ｗ２が２以上の整数である場合、複数のＲ^b20は互いに同一か相異なり、ｘ２が２以上の整数である場合、複数のＲ^b21は互いに同一か相異なる。
なかでも、Ｒ^b19〜Ｒ^b21は、それぞれ独立に、好ましくは、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、炭素数１〜１２のアルキル基、又は炭素数１〜１２のアルコキシ基であることが好ましく、ヒドロキシ基又は炭素数１〜４のアルキル基であることがより好ましい。

In formula (b2-1-1),
R ^{b19 to} R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or a carbon number. 1 to 12 alkoxy groups are represented.
The aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, and the saturated cyclic hydrocarbon group preferably has 4 to 18 carbon atoms.
The aliphatic hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
The saturated cyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1). When v2 is an integer of 2 or more, the plurality of R ^b19 are the same or different from each other, and when w2 is an integer of 2 or more, the plurality of R ^b20 are the same or different from each other, and x2 is an integer of 2 or more In this case, the plurality of R ^b21 are the same or different from each other.
Among them, R ^{b19 to} R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. It is preferably a hydroxy group or an alkyl group having 1 to 4 carbon atoms.

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 ) And (B1-3) are 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). 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（Ｃ２）及び式（Ｃ２−１）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又は芳香族炭化水素基を表す。但し該脂肪族炭化水素基、該飽和環状炭化水素基又は該芳香族炭化水素基に含まれる水素原子は、ヒドロキシ基、アミノ基、又は炭素数１〜６のアルコキシ基で置換されていてもよく、該アミノ基は、炭素数１〜４のアルキル基で置換されていてもよく、該脂肪族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。
前記脂肪族炭化水素基は、好ましくは炭素数１〜１８程度であり、前記飽和環状炭化水素基は、好ましくは炭素数５〜１０程度であり、前記芳香族炭化水素基は、好ましくは炭素数６〜１０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）、アルコキシ基、飽和環状炭化水素基（好ましくはシクロアルキル基）又は芳香族炭化水素基を表す。但し該脂肪族炭化水素基、該アルコキシ基、該飽和環状炭化水素基及び該芳香族炭化水素基に含まれる水素原子は、上記と同様の基で置換基されていてもよい。
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、好ましくは炭素数１〜６程度である。

In formula (C2) and formula (C2-1), Ar ^c1 represents an aromatic hydrocarbon group.
R ^c5 and R ^c6 each independently represents 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 hydrogen atom contained in the aliphatic hydrocarbon group, the saturated cyclic hydrocarbon group or the aromatic hydrocarbon group may be substituted with a hydroxy group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. The amino group may be substituted with an alkyl group having 1 to 4 carbon atoms, and —CH ₂ — contained in the aliphatic hydrocarbon group may be replaced with —O— or —CO—. .
The aliphatic hydrocarbon group preferably has about 1 to 18 carbon atoms, the saturated cyclic hydrocarbon group preferably has about 5 to 10 carbon atoms, and the aromatic hydrocarbon group preferably has about carbon atoms. It is about 6-10.
R ^c7 represents an aliphatic hydrocarbon group (preferably an alkyl group), an alkoxy group, a saturated cyclic hydrocarbon group (preferably a cycloalkyl group) or an aromatic hydrocarbon group. However, hydrogen atoms contained in the aliphatic hydrocarbon group, the alkoxy group, the saturated cyclic hydrocarbon group, and the aromatic hydrocarbon group may be substituted with the same groups as described 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 1 to 6 carbon atoms.

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（Ｃ３）〜式（Ｃ１１）中、
Ｒ^c8は、上記Ｒ^c7で説明したいずれかの基を表す。
窒素原子と結合する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。
芳香族炭素と結合する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、ｐ３、ｑ３、ｒ３、ｓ３、ｔ３及びｕ３は、それぞれ独立に０〜３の整数を表す。ｏ３、ｐ３、ｑ３、ｒ３、ｓ３、ｔ３及び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、好ましくは炭素数１〜６程度であり、飽和環状炭化水素基は、好ましくは炭素数３〜６程度であり、アルカノイル基は、好ましくは炭素数２〜６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。該２価の脂肪族炭化水素基は、好ましくは炭素数１〜６程度である。
Ｒ^c3は、炭素数１〜４のアルキル基を表す。 Examples of the basic compound (C) include compounds represented by the formulas (C3) to (C11).

In formula (C3) to formula (C11),
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 bonded to the nitrogen atom each independently represent any of the groups described for R ^c5 and R ^c6 .
R ^c20 , R ^c21 and R ^{c23 to} R ^c28 bonded to the aromatic carbon each independently represents any of the groups described for R ^c7 .
o3, p3, q3, r3, s3, t3 and u3 each independently represents an integer of 0 to 3. When any of o3, p3, q3, r3, s3, t3, and 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 represented by R ^c15 preferably has about 1 to 6 carbon atoms, the saturated cyclic hydrocarbon group preferably has about 3 to 6 carbon atoms, and the alkanoyl group preferably has 2 to 6 carbon atoms. 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 preferably has about 1 to 6 carbon atoms.
R ^c3 represents an alkyl group having 1 to 4 carbon atoms.

  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, 4- (12-hydroxydodecanyl) morpholine, 4- [2-[(2-methoxyethoxy) ethoxy] ethyl] morpholine, and the like.
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.

<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, for example, sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes 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) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer using an exposure machine;
(4) A step of heating the composition layer after exposure,
(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.

Drying is performed, for example, by evaporating and removing volatile components such as a solvent by using a heating device such as a hot plate (so-called pre-baking), or by using a decompression device and drying the composition layer. Is formed. 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. 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.) can be used such as those that convert the wavelength of the laser light from the above and radiate the harmonic laser light in the far ultraviolet region or the vacuum ultraviolet region. Further, the exposure machine may irradiate an electron beam or extreme ultraviolet light (EUV).

The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) 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 is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) irradiation, or a resist composition for EUV exposure. is there.

Hereinafter, the present invention will be described in detail by way of examples. In the examples,% and parts representing the content and the amount used 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 compounds used in Examples and Comparative Examples are shown below.

Synthesis of Resin A1 Monomer represented by formula (A), monomer represented by formula (E), monomer represented by formula (B), monomer represented by formula (H) and formula (C) The monomer to be prepared was charged at a molar ratio of 32: 7: 8: 10: 43, and 1.5 weight times dioxane of the total monomer amount was added to prepare a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to the total monomer amount, respectively, and heated at 73 ° 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 9.5 × 10 ^{3 in} a yield of 80%. . This copolymer has a structural unit derived from a monomer of the following formula, and this is designated as resin A1.

Synthesis of Resin A2 Monomer represented by formula (A), monomer represented by formula (G), monomer represented by formula (B), monomer represented by formula (H) and formula (C) The monomer to be prepared was charged at a molar ratio of 32: 7: 8: 10: 43, and 1.5 weight times dioxane of the total monomer amount was added to prepare a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to the total monomer amount, respectively, and heated at 73 ° 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 9.2 × 10 ^{3 in} a yield of 75%. . This copolymer has a structural unit derived from a monomer of the following formula, and this is designated as resin A2.

Synthesis of Resin A3 Monomer represented by formula (A), monomer represented by formula (E), monomer represented by formula (B), monomer represented by formula (D) and formula (C) The monomer to be prepared was charged at a molar ratio of 32: 7: 8: 10: 43, and 1.5 weight times dioxane of the total monomer amount was added to prepare a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to the total monomer amount, respectively, and heated at 73 ° 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 8.9 × 10 ^{3 in} a yield of 78%. . This copolymer has a structural unit derived from a monomer of the following formula, and this is designated as resin A3.

Synthesis of Resin A4 Monomer represented by formula (A), monomer represented by formula (G), monomer represented by formula (F), monomer represented by formula (H) and formula (C) The monomer to be prepared was charged at a molar ratio of 32: 7: 4: 14: 43, and 1.5 weight times dioxane of the total monomer amount was added to prepare a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to the total monomer amount, respectively, and heated at 73 ° 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 9.0 × 10 ^{3 in} a yield of 70%. . This copolymer has a structural unit derived from a monomer of the following formula, and this is designated as resin A4.

Synthesis of Resin A5 A compound represented by formula (M), a compound represented by formula (B), a compound represented by formula (N), and a compound represented by formula (O) were prepared at 25:25:40. The mixture was charged at a molar ratio of 10 and dioxane 1.5 times the total monomer amount was added to prepare 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 77 ° 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 7.6 × 10 ^{3 in} a yield of 60%. . This copolymer has a structural unit derived from a monomer represented by the following formula, and this is designated as resin A5.

Synthesis of Resin A6 Monomer represented by formula (T), monomer represented by formula (E), monomer represented by formula (B), monomer represented by formula (D), and formula (C) The monomer to be prepared was charged at a molar ratio of 30: 14: 6: 30: 20, and 1.5 weight times dioxane of the total monomer amount was added to prepare a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to the total monomer amount, respectively, and heated at 73 ° 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 8.1 × 10 ^{3 in} a yield of 65%. . This copolymer has a structural unit derived from a monomer of the following formula, and this is designated as resin A6.

Synthesis of Polymer D1 The monomer represented by the formula (I) and the monomer represented by the formula (J) were charged at a molar ratio of 50:50, 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 1.8 × 10 ^{4 in} a yield of 60%. . This copolymer has each structural unit derived from the monomer of the following formula, and this is designated as polymer D1.

Synthesis of Polymer D2 The monomer represented by the formula (I) and the monomer represented by the formula (J) were charged at a molar ratio of 70:30, 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 1.7 × 10 ^{4 in} a yield of 62%. . This copolymer has each structural unit derived from the monomer of the following formula, and this is designated as polymer D2.

Synthesis of Polymer D3 A monomer represented by formula (I) and a monomer represented by formula (J) were charged at a molar ratio of 70:30, and 1.5 wt. . As initiators, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added in an amount of 0.3 mol% and 0.9 mol% based on the total amount of monomers, respectively, and heated at 67 ° 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 5.2 × 10 ^{4 in} a yield of 87%. . This copolymer has each structural unit derived from the monomer of the following formula, and this is designated as polymer D3.

Synthesis of Polymer D4 The monomer represented by the formula (I) and the monomer represented by the formula (K) were charged at a molar ratio of 70:30, and dioxane which was 1.5 times the total monomer amount was added to form a solution. . As initiators, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added in an amount of 0.4 mol% and 1.2 mol%, respectively, based on the total amount of monomers, and heated at 67 ° 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 4.5 × 10 ^{4 in} a yield of 72%. . This copolymer has each structural unit derived from the monomer of the following formula, and this is designated as polymer D4.

Synthesis of Polymer D5 A monomer represented by formula (I) and a monomer represented by formula (L) were charged at a molar ratio of 70:30, and 1.5 wt. . As initiators, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added in an amount of 0.4 mol% and 1.2 mol%, respectively, based on the total amount of monomers, and heated at 67 ° 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 4.9 × 10 ^{4 in} a yield of 77%. . This copolymer has each structural unit derived from the monomer of the following formula, and this is designated as polymer D5.

Synthesis of Polymer D6 The monomer represented by the formula (I) and the monomer represented by the formula (R) were charged at a molar ratio of 80:20, and 1.5 wt. . As initiators, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added in an amount of 0.4 mol% and 1.2 mol%, respectively, based on the total monomer amount, and heated at 70 ° 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 3.8 × 10 ^{4 in} a yield of 78%. . This copolymer has each structural unit derived from the monomer of the following formula, and this is designated as polymer D6.

Synthesis of Polymer D7 The monomer represented by the formula (I) and the monomer represented by the formula (S) were charged at a molar ratio of 70:30, and 1.5 wt. . As initiators, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added in an amount of 0.3 mol% and 0.9 mol% based on the total amount of monomers, respectively, and heated at 70 ° 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 4.9 × 10 ^{4 in} a yield of 82%. . This copolymer has each structural unit derived from the monomer of the following formula, and this is designated as polymer D7.

Synthesis of Polymer D8 The monomer represented by formula (Q) and the monomer represented by formula (J) were charged at a molar ratio of 70:30, and 1.5 wt. . As initiators, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added in an amount of 0.3 mol% and 0.9 mol% based on the total amount of monomers, respectively, and heated at 70 ° 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 5.1 × 10 ^{4 in} a yield of 85%. . This copolymer has each structural unit derived from the monomer of the following formula, and this is designated as polymer D8.

Synthesis of Polymer X1 A monomer represented by formula (J) and a monomer represented by formula (P) were charged at a molar ratio of 50:50, and 1.5 wt. It was. 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 80 ° 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 9.3 × 10 ^{3 in} a yield of 55%. . This copolymer has a structural unit derived from the monomer of the following formula, and this is designated as a polymer X1.

Examples and Comparative Examples The above components and the following components were mixed and dissolved in the compositions shown in Table 1 and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

Ｂ２：トリフェニルスルホニウム パーフルオロブタンスルホナート <Resin>
A1: Resin A1
A2: Resin A2
A3: Resin A3
A4: Resin A4
A5: Resin A5
A6: Resin A6
<Polymer>
D1: Polymer D1
D2: Polymer D2
D3: Polymer D3
D4: Polymer D4
D5: Polymer D5
D6: Polymer D6
D7: Polymer D7
D8: Polymer D8
X1: Polymer X1
<Acid generator>
B1: Salt represented by the formula (B1-3)

B2: Triphenylsulfonium perfluorobutanesulfonate

＜溶剤＞
プロピレングリコールモノメチルエーテルアセテート ２６５．０部
プロピレングリコールモノメチルエーテル ２０．０部
２−ヘプタノン ２０．０部
γ−ブチロラクトン ３．５部 <Basic compound (quencher)>
C1: 2,6-diisopropylaniline C2: compound represented by the formula (C2)

<Solvent>
Propylene glycol monomethyl ether acetate 265.0 parts Propylene glycol monomethyl ether 20.0 parts 2-heptanone 20.0 parts γ-butyrolactone 3.5 parts

<Defect evaluation>
The resist composition was spin-coated on a 12-inch silicon wafer so that the film thickness after drying (pre-baking) was 0.15 μm. After applying the resist composition, it was pre-baked (PB) for 60 seconds on the direct hot plate at the temperature shown in the PB column of Table 1.
The wafer on which the resist composition film was formed in this manner was rinsed with water for 60 seconds using a developing machine [ACT-12; manufactured by Tokyo Electron Ltd.].
Thereafter, the number of defects on the wafer was measured using a defect inspection apparatus [KLA-2360; manufactured by KLA Tencor].
The number of defects was evaluated as ◯ when the number of defects was 1000 or less (in particular, ◎ is 500 or less, ◎ is 300 or less), x is 5000 or more, and it is more than 1000 and less than 5000. The results are shown in Table 2.

(Immersion exposure evaluation of resist composition)
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Co., Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a thickness of 780 mm. 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.
After applying the resist composition, the obtained silicon wafer 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 laser stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light] on the wafer having the resist composition film formed thereon, the exposure amount is stepped. The line and space pattern was subjected to immersion exposure. 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 forming a resist pattern from each resist composition, the exposure amount at which the line width of a 50 nm line-and-space pattern was 1: 1 was defined as effective sensitivity.

  Mask error factor evaluation (MEF): Resist patterns were formed using masks having mask sizes of 48 nm, 50 nm, and 52 nm (pitch are both 100 nm) in effective sensitivity. The mask size is plotted on the horizontal axis, and the line width of the resist pattern formed using the mask of each mask size is plotted on the vertical axis. When the slope of the regression line obtained from the plot was 2.5 or less, it was evaluated as ◯, when it exceeded 2.5 and was 3.0 or less, Δ, and when it was more than 3.0, ×. Here, the mask size means the size of the pattern transferred to the substrate by exposure, and does not mean the size of the translucent part formed on the mask.

Focus margin evaluation (DOF): In terms of effective sensitivity, a focus range (47.5 to 52.5 nm) in which the line width of a resist pattern formed by changing the focus stepwise is 50 nm ± 5% is used as an index (DOF). , One having a DOF of 0.15 μm or more (Among them, one having a DOF of 0.17 μm or more is ◎), one having a DOF of less than 0.10 μm and less than 0.15 μm, and one having a DOF of less than 0.10 μm Was marked with x.
These results are shown in Table 2.

  The resist composition of the present invention is excellent in mask error factor (MEF) and focus margin (DOF) when forming a resist pattern. Moreover, according to the resist composition of this invention, a pattern with few defects can be formed.

Claims (6)

A polymer having a group represented by the formula (I) and a group represented by the formula (II), having no acid-labile group, an acid-labile group, and an alkaline aqueous solution A resist composition comprising a resin that is insoluble or hardly soluble in water and can be dissolved in an alkaline aqueous solution by the action of an acid, and an acid generator.

[In Formula (I), R ¹ represents a fluorinated alkyl group having 1 to 6 carbon atoms. * Represents a bond. ]

[In Formula (II), R ² represents a fluorinated alkyl group having 1 to 6 carbon atoms.
R ³ represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms. * Represents a bond. ] The resist composition according to claim 1, wherein the polymer is a polymer having a structural unit derived from the compound represented by formula (I-1).

[In formula (I-1), R ¹ represents the same meaning as described above.
R ⁴ represents a hydrogen atom or a methyl group.
A ¹ represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. ] The resist composition according to claim 1 or 2, wherein the polymer is a polymer having a structural unit derived from the compound represented by the formula (II-1).

[In formula (II-1), R ² and R ³ represent the same meaning as described above.
R ⁵ represents a hydrogen atom or a methyl group.
B ¹ represents a divalent saturated hydrocarbon group having 1 to 10 carbon atoms. ] The resist composition according to claim 1, wherein the acid generator 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 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. May be.
Y represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent or a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the aliphatic group —CH ₂ — contained in the hydrocarbon group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]   Furthermore, the resist composition in any one of Claims 1-4 containing a basic compound. (1) The process of apply | coating the resist composition in any one of Claims 1-5 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer using an exposure machine;
(4) A step of heating the composition layer after exposure,
(5) a step of developing the heated composition layer using a developing device;
A method for producing a resist pattern including: