JP2012145924A - Resist composition and production method of resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a resist pattern with excellent CD uniformity (CDU).SOLUTION: The present invention presents a composition containing a resin (X) having a structural unit expressed by formulae (aa), (ab) and an acid generator (B). In the formulae, Arepresents a group such as an alkane-diyl group optionally having a substituent; Rrepresents an aliphatic hydrocarbon group; and Rrepresents an aromatic hydrocarbon group.

Description

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

In recent years, as a semiconductor microfabrication technique, an optical lithography technique using short-wavelength light such as an ArF excimer laser (wavelength: 193 nm) as an exposure source has been actively studied. Examples of the resist composition used in such a photolithography technique include a resin composed of a structural unit represented by the formula (u-A) and a structural unit represented by the formula (u-B), and a formula (u A resin comprising a structural unit represented by -B), a structural unit represented by formula (u-C), and a structural unit represented by formula (u-D), an acid generator, and a solvent. A resist composition is known (Patent Document 1).

JP 2010-197413 A

  A resist pattern obtained by using the above-described resist composition that has been conventionally known may not always satisfy CD uniformity (CDU).

［式（ａａ）中、
Ａ^aa1は、置換基を有していてもよい炭素数１〜６のアルカンジイル基又は式（ａ−１）で表される基を表す。

（式（ａ−１）中、
ｓは０又は１の整数を表す。
Ａ¹⁰、Ａ^1１及びＡ¹²は、それぞれ独立に、置換基を有していてもよい炭素数１〜５の２価の脂肪族炭化水素基を表す。
Ｘ¹⁰及びＸ^1１は、それぞれ独立に、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ｒ^aa1は、水素原子又はメチル基を表す。
Ｒ^aa2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を表し、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］

［式（ａｂ）中、
Ａ^ab1は、単結合、置換基を有していてもよい炭素数１〜６のアルカンジイル基又は式（ａ−２）で表される基を表す。

（式（ａ−２）中、
ｔは０又は１の整数を表す。
Ａ³⁰、Ａ³¹及びＡ³²は、それぞれ独立に、置換基を有していてもよい炭素数１〜５の２価の脂肪族炭化水素基を表す。
Ｘ³⁰及びＸ³¹は、それぞれ独立に、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
＊は−Ｏ−Ｃ（Ｏ）−Ｏ−ＣＨ_２−Ｒ^ab2との結合手である。）
Ｒ^ab1は、水素原子又はメチル基を表す。
Ｒ^ab2は、炭素数６〜１８の芳香族炭化水素基を表す。］ The present invention includes the following inventions.
[1] A resist composition comprising a resin (X) having a structural unit represented by formula (aa) and a structural unit represented by formula (ab), and an acid generator (B).

[In the formula (aa)
A ^aa1 represents a C1-C6 alkanediyl group which may have a substituent or a group represented by the formula (a-1).

(In the formula (a-1),
s represents an integer of 0 or 1.
A ¹⁰ , A ¹¹ and A ¹² each independently represent a C 1-5 divalent aliphatic hydrocarbon group which may have a substituent.
X ¹⁰ and X ¹¹ each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
R ^aa1 represents a hydrogen atom or a methyl group.
R ^aa2 represents an ^optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. Good. ]

[In the formula (ab),
A ^ab1 represents a single bond, an alkanediyl group having 1 to 6 carbon atoms which may have a substituent, or a group represented by the formula (a-2).

(In the formula (a-2),
t represents an integer of 0 or 1.
A ³⁰ , A ³¹ and A ³² each independently represent a C 1-5 divalent aliphatic hydrocarbon group which may have a substituent.
X ³⁰ and X ³¹ each independently represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
* Is a bond with —O—C (O) —O—CH ₂ —R ^ab2 . )
R ^ab1 represents a hydrogen atom or a methyl group.
R ^ab2 represents an aromatic hydrocarbon group having 6 to 18 carbon atoms. ]

[2] The resist composition according to [1], wherein ^{Aaa1 in the} formula (aa) is an alkanediyl group having 1 to 6 carbon atoms.
[3] The resist composition according to [1] or [2], wherein ^{Aaa1 in the} formula (aa) is a methylene group.
[4] The resist composition according to any one of [1] to [3], wherein A ^{ab1 in the} formula (ab) is an alkanediyl group having 1 to 6 carbon atoms.
[5] The resist composition according to any one of [1] to [4], wherein A ^{ab1 in the} formula (ab) is an ethylene group.
[6] ^Rab2 in the formula (ab) is a group represented by the formula (ab-1) or a group represented by the formula (ab-2) [1] to [5] Resist composition.

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１〜１７の２価の脂肪族炭化水素基を表し、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
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を表し、該脂肪族炭化水素基を構成するメチレン基は、酸素原子、スルホニル基又はカルボニル基に置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］
〔８〕前記式（Ｂ１）のＹが、置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基である〔７〕記載のレジスト組成物。
〔９〕さらに、アルカリ水溶液に不溶又は難溶であり、酸の作用によりアルカリ水溶液に可溶となる樹脂（Ａ）を含有する〔１〕〜〔８〕のいずれか記載のレジスト組成物。
〔１０〕さらに溶剤を含む〔１〕〜〔９〕のいずれか記載のレジスト組成物。 [7] The resist composition according to any one of [1] to [6], wherein (B) is an acid generator 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 divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y represents an optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group is replaced with an oxygen atom, a sulfonyl group or a carbonyl group. May be.
Z ⁺ represents an organic cation. ]
[8] The resist composition according to [7], wherein Y in the formula (B1) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent.
[9] The resist composition according to any one of [1] to [8], further comprising a resin (A) that is insoluble or hardly soluble in an alkaline aqueous solution and becomes soluble in an alkaline aqueous solution by the action of an acid.
[10] The resist composition according to any one of [1] to [9], further containing a solvent.

[11] (1) A step of applying the resist composition according to any one of [1] to [10] 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,
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating,
A method for producing a resist pattern including:

  According to the resist composition of the present invention, a resist pattern having excellent CD uniformity (CDU) can be produced.

  In the present specification, unless otherwise specified, the following examples of substituents are applied to any chemical structural formula having the same substituents while appropriately selecting the number of carbon atoms. Those which can be linear, branched or cyclic include any of them, and they may be mixed. When stereoisomers exist, all stereoisomers are included. * Represents a bond.

The hydrocarbon group includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group.
Aliphatic hydrocarbon groups include both chain and cyclic groups, and unless otherwise defined, also include combinations of chain and cyclic aliphatic hydrocarbon groups. Moreover, although these aliphatic hydrocarbon groups may contain the carbon-carbon double bond in the part, a saturated group is preferable.
Of the chain aliphatic hydrocarbon groups, the monovalent one typically includes an alkyl group.
Examples of the alkyl group include a methyl group (C ₁ ), an ethyl group (C ₂ ), a propyl group (C ₃ ), a butyl group (C ₄ ), a pentyl group (C ₅ ), a hexyl group (C ₆ ), a heptyl group ( C ₇ ), octyl group (C ₈ ), decyl group (C ₁₀ ), dodecyl group (C ₁₂ ), hexadecyl group (C ₁₄ ), pentadecyl group (C ₁₅ ), hexyldecyl group (C ₁₆ ), heptadecyl group ( C ₁₇ ) and octadecyl group (C ₁₈ ).
Examples of the divalent group of chain aliphatic hydrocarbon groups include alkanediyl groups in which one hydrogen atom has been removed from an alkyl group.
Examples of alkanediyl groups include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane- 1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl Group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1 , 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3 − Yl group, 2-methylpropane-1,2-diyl, pentane-1,4-diyl group, a 2-methylbutane-1,4-diyl group.

  The cyclic aliphatic hydrocarbon group (hereinafter sometimes referred to as “alicyclic hydrocarbon group”) typically means a cycloalkyl group, and includes any of the monocyclic and polycyclic groups shown below. Is also included.

As a monovalent alicyclic hydrocarbon group, a monocyclic aliphatic hydrocarbon group represents 1 hydrogen atom of a cycloalkane represented by the following formulas (KA-1) to (KA-7). It is a group that has been removed.

The polycyclic aliphatic hydrocarbon group is a group in which one hydrogen atom of a cycloalkane represented by the following formulas (KA-8) to (KA-22) is removed.

  Examples of the divalent alicyclic hydrocarbon group include groups in which two hydrogen atoms have been removed from the alicyclic hydrocarbon of formula (KA-1) to formula (KA-22).

The aliphatic hydrocarbon group may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, an alkoxy group, an acyl group, an acyloxy group, an aryl group, an aralkyl group, and an aryloxy group, unless otherwise specified.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of alkoxy groups include methoxy group (C ₁ ), ethoxy group (C ₂ ), propoxy group (C ₃ ), butoxy group (C ₄ ), pentyloxy group (C ₅ ), hexyloxy group (C ₆ ), heptyl Examples thereof include an oxy group (C ₇ ), an octyloxy group (C ₈ ), a decyloxy group (C ₁₀ ), and a dodecyloxy group (C ₁₂ ).
Examples of the acyl group include acetyl group (C ₂ ), propionyl group (C ₃ ), butyryl group (C ₄ ), valeryl group (C ₅ ), hexanoyl group (C ₆ ), heptanoyl group (C ₇ ), octanoyl group ( Examples include those in which an alkyl group such as C ₈ ), decanoyl group (C ₁₀ ) and dodecanoyl group (C ₁₂ ) is bonded to a carbonyl group, and those in which an aryl group such as benzoyl group (C ₇ ) is bonded to a carbonyl group It is done.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, and an isobutyryloxy group.
Examples of the aralkyl group include benzyl group (C ₇ ), phenethyl group (C ₈ ), phenylpropyl group (C ₉ ), naphthylmethyl group (C ₁₁ ), and naphthylethyl group (C ₁₂ ).
The aryloxy group includes phenyloxy group (C ₆ ), naphthyloxy group (C ₁₀ ), antonyloxy group (C ₁₄ ), biphenyloxy group (C ₁₂ ), phenanthryloxy group (C ₁₄ ) and full A combination of an aryl group such as an oleenyloxy group (C ₁₃ ) and an oxygen atom is exemplified.

A typical example of the aromatic hydrocarbon group is an aryl group.
Examples of the aryl group include a phenyl group (C ₆ ), a naphthyl group (C ₁₀ ), an anthryl group (C ₁₄ ), a biphenyl group (C ₁₂ ), a phenanthryl group (C ₁₄ ), and a fluorenyl group (C ₁₃ ). .
The aromatic hydrocarbon group may have a substituent. Unless such a substituent is particularly limited, a halogen atom, a hydroxy group, an alkoxy group, an acyl group, an acyloxy group, an alkyl group, and an aryloxy group are exemplified.

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

<Resist composition>
The resist composition of the present invention (hereinafter sometimes referred to as “the present resist composition”) contains at least a resin (X) and an acid generator (B). Moreover, resin different from resin (X) may be contained.
Furthermore, additives such as a base compound called a solvent and / or a quencher may be included as necessary.

<Resin (X)>
Resin (X) includes a structural unit represented by the formula (aa) (hereinafter sometimes referred to as “structural unit (aa)” in some cases) and a structural unit represented by the formula (ab) (hereinafter, sometimes represented by And may be referred to as “structural unit (ab)”.

［式（ａａ）中、
Ａ^aa1は、置換基を有していてもよい炭素数１〜６のアルカンジイル基又は式（ａ−１）で表される基を表す。

（式（ａ−１）中、
ｓは０又は１の整数を表す。
Ａ¹⁰、Ａ^1１及びＡ¹²は、それぞれ独立に、置換基を有していてもよい炭素数１〜５の２価の脂肪族炭化水素基を表す。
Ｘ¹⁰及びＸ^1１は、それぞれ独立に、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。）
Ｒ^aa1は、水素原子又はメチル基を表す。
Ｒ^aa2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を表し、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］ <Structural unit (aa)>

[In the formula (aa)
A ^aa1 represents a C1-C6 alkanediyl group which may have a substituent or a group represented by the formula (a-1).

(In the formula (a-1),
s represents an integer of 0 or 1.
A ¹⁰ , A ¹¹ and A ¹² each independently represent a C 1-5 divalent aliphatic hydrocarbon group which may have a substituent.
X ¹⁰ and X ¹¹ each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group. )
R ^aa1 represents a hydrogen atom or a methyl group.
R ^aa2 represents an ^optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. Good. ]

In the formula (aa), ^examples of the alkanediyl group of A ^aa1 include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane- Linear alkanediyl groups such as 1,5-diyl group and hexane-1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2- Examples thereof include branched alkanediyl groups such as methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, and 2-methylbutane-1,4-diyl group.
Examples of the substituent in the alkanediyl group include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.

The group represented by the formula (a-1) (hereinafter sometimes referred to as “group (a-1)”) is an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group, as in X ¹⁰ and X ^11. It may have a partial structure including the like.
Examples of the divalent aliphatic hydrocarbon group for A ¹⁰ , A ^11, and A ¹² include a divalent chain aliphatic hydrocarbon group.
Examples of the substituent in A ¹⁰ , A ^11, and A ¹² include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
Examples of the group (a-1) having an oxygen atom include the following groups.

Examples of the group (a-1) having a carbonyl group include the following groups.

Examples of the group (a-1) having a carbonyloxy group include the following groups.

Examples of the group (a-1) having an oxycarbonyl group include the following groups.

Among them, A ^aa1 in formula (aa) is preferably an alkanediyl group having 1 to 6 carbon atoms, more preferably an alkanediyl group having 1 to 4 carbon atoms, and further preferably a methylene group.

The aliphatic hydrocarbon group for R ^aa2 may partially have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group. Preferred examples of the aliphatic hydrocarbon group include an alkyl group (the alkyl group may be linear or branched), an alicyclic hydrocarbon group, and a group obtained by combining these.

Examples of the substituent for R ^aa2 include a halogen atom, an alkoxy group, an acyl group, and an alkoxycarbonyl group. When R ^aa2 is an aliphatic hydrocarbon group having a substituent, the total number of carbon atoms including the carbon atoms in the substituent is preferably 18 or less. The alkoxycarbonyl group is a combination of an alkoxy group and a carbonyl group. Of these substituents, a fluorine atom is preferred.
In particular, R ^aa2 is preferably an aliphatic hydrocarbon group having a fluorine atom.
Examples of the aliphatic hydrocarbon group having a fluorine atom include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 1,1,1-trifluoroethyl group, 2, 2,2-trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,1,2,2-pentafluoropropyl 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 1,1,1,2,2,3,3-peptafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3, 4,4-oct Fluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3 , 4,4-octafluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl 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, perfluoropentylmethyl, pe Fluorohexyl group, perfluoroheptyl group and a perfluorooctyl group.
Among them, the aliphatic hydrocarbon group having a fluorine atom is preferably a triperfluoromethyl group, 1,1,1-trifluoroethyl group, perfluoroethyl group, 1,1,1,2,2-pentafluoro. Propyl group, perfluoropropyl group, 1,1,1,2,2,3,3-heptafluorobutyl group, perfluorobutyl group, 1,1,1,2,2,3,3,4,4-nonafluoro A pentyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, a perfluorooctyl group, and the like, more preferably a perfluoroalkyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkyl group having 1 to 3 carbon atoms. It is an alkyl group.
In addition, the methylene group constituting the aliphatic hydrocarbon group for R ^aa2 may be replaced with an oxygen atom or a carbonyl group. In this case, it is suitable that the number of methylene groups replaced with oxygen atoms or carbonyl groups is at most 2.

Examples of the structural unit (aa) include the following structural units.

In the structural unit (aa) represented by any one of the formulas (aa-1) to (aa-14), a structural unit (aa) in which the partial structure (Mc) shown below is replaced with a partial structure (Ac) ) Can be mentioned as preferred specific examples.

The structural unit (aa) is derived from a compound represented by the formula (aa ′) (hereinafter sometimes referred to as “compound (aa ′)”). Compound (aa ′) can be produced, for example, by the method represented by the following reaction formula.

The compound represented by the formula (aas-1) and the compound represented by the formula (aas-2) are preferably reacted in a solvent in the presence of a catalyst. Examples of the solvent include dimethylformamide. Examples of the catalyst include potassium carbonate and potassium iodide.
As the compound represented by the formula (aas-1), typically a compound (commercially available) that can be easily obtained from the market is preferable. Such commercial products are methacrylic acid and the like.

The compound represented by the formula (aas-2) can be produced, for example, by reacting a compound represented by the formula (aas-3) with a compound represented by the formula (aas-4). This reaction is carried out in a solvent in the presence of a base catalyst. Examples of the solvent used in this reaction include tetrahydrofuran. Examples of the base catalyst include pyridine.

Examples of the compound represented by the formula (aas-3) include chloroacetyl chloride. This compound is readily available from the market.
Examples of the compound represented by the formula (aas-4), can be used an appropriate alcohol according to the type of the desired R ^aa2. For example, alcohols such as 2,2,3,3,4,4,4-heptafluoro-1-butanol can be mentioned. This compound is readily available from the market.

［式（ａｂ）中、
Ａ^ab1は、単結合、置換基を有していてもよい炭素数１〜６のアルカンジイル基又は式（ａ−２）で表される基を表す。

（式（ａ−２）中、
ｔは０又は１の整数を表す。
Ａ³⁰、Ａ³¹及びＡ³²は、それぞれ独立に、置換基を有していてもよい炭素数１〜５の２価の脂肪族炭化水素基を表す。
Ｘ³⁰及びＸ³¹は、それぞれ独立に、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
＊は−Ｏ−Ｃ（Ｏ）−Ｏ−ＣＨ_２−Ｒ^ab2との結合手である。）
Ｒ^ab1は、水素原子又はメチル基を表す。
Ｒ^ab2は、炭素数６〜１８の芳香族炭化水素基を表す。］ <Structural unit (ab)>

[In the formula (ab),
A ^ab1 represents a single bond, an alkanediyl group having 1 to 6 carbon atoms which may have a substituent, or a group represented by the formula (a-2).

(In the formula (a-2),
t represents an integer of 0 or 1.
A ³⁰ , A ³¹ and A ³² each independently represent a C 1-5 divalent aliphatic hydrocarbon group which may have a substituent.
X ³⁰ and X ³¹ each independently represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
* Is a bond with —O—C (O) —O—CH ₂ —R ^ab2 . )
R ^ab1 represents a hydrogen atom or a methyl group.
R ^ab2 represents an aromatic hydrocarbon group having 6 to 18 carbon atoms. ]

In the formula (ab), as the substituent for the alkanediyl group, a hydroxy group and an alkoxy group having 1 to 6 carbon atoms are suitable.
Examples of the aliphatic hydrocarbon group for A ³⁰ , A ³¹ and A ³² include the same aliphatic hydrocarbon groups for A ¹⁰ , A ¹¹ and A ¹² .
^Examples of the substituent in A ³⁰ , A ³¹ and A ³² include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.

The group represented by the formula (a-2) (hereinafter sometimes referred to as “group (a-2)”) is an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group, as in X ³⁰ and X ^31. It may have a partial structure including the like.
Examples of the group (a-2) are the same as those exemplified as the group (a-1).

Among them, A ^ab1 of the structural unit (ab) is preferably an alkanediyl group having 1 to 6 carbon atoms, more preferably an alkanediyl group having 1 to 4 carbon atoms, and further preferably an ethylene group.

R ^ab2 is preferably an aromatic hydrocarbon group having 6 to 14 carbon atoms. Among them, the group (a1-1) or the group (a1-2) is preferable, and the group (a1-1) is more preferable.

Examples of the structural unit (ab) include the following structural units.

  In addition, in the structural unit (ab) represented by any one of the formulas (ab-1) to (ab-8), the above-described partial structure (Mc) is replaced with the partial structure (Ac). It can be mentioned as a specific example of ab).

式（ａｂｓ−１）で表される化合物と式（ａｂｓ−２）で表される化合物とは、溶媒中、塩基性触媒の存在下で反応させることが好ましい。溶媒としては、メチルイソブチルケトンなどが挙げられる。塩基性触媒としては、ピリジンなどが挙げられる。 The structural unit (ab) is derived from a compound represented by the formula (ab ′) (hereinafter sometimes referred to as “compound (aa ′)”). Compound (ab ′) can be produced, for example, by the reaction shown below.

The compound represented by the formula (abs-1) and the compound represented by the formula (abs-2) are preferably reacted in a solvent in the presence of a basic catalyst. Examples of the solvent include methyl isobutyl ketone. Examples of the basic catalyst include pyridine.

Examples of the compound represented by the formula (abs-1) include hydroxyethyl methacrylate, and this compound can be easily obtained from the market.
Examples of the compound represented by the formula (abs-2) include fluorenylmethyl chloroformate and the like, and this compound can be easily obtained from the market.

  In the resin (X), the structural unit (aa) and the structural unit (ab) may each be one kind, one may be plural kinds, the other may be one kind, or the structural unit. Both (aa) and the structural unit (ab) may be of plural types. Among these, the structural unit (aa) and the structural unit (ab) each preferably have one type in that the resin (X) can be easily produced. Examples of combinations of the structural unit (aa) and the structural unit (ab) are shown in Table 1 below. In Table 1, the structural unit (aa) represented by the formula (aa-1) is represented as “(aa-1)” according to the formula number, and similarly in the formula (ab-1) The represented structural unit (ab) or the like is represented as “(ab-1)” according to the formula number. For example, the notation “(aa-1) / (aa-3)” is represented by the structural unit (aa), the structural unit represented by the formula (aa-1), and the formula (aa-3). Together with a structural unit.

The total content of the structural unit (aa) and the structural unit (ab) with respect to the total structural unit (100 mol%) of the resin (X) is preferably in the range of 1 to 100 mol%, more preferably in the range of 5 to 100 mol%. The range of 10 to 100 mol% is more preferable, and the range of 50 to 100 mol% is particularly preferable.
The content ratio of the structural unit (aa) to the total structural unit (100 mol%) of the resin (X) is preferably in the range of 5 to 95 mol%, more preferably in the range of 10 to 90 mol%, and 40 to 90 mol%. The range of is more preferable.
The content ratio of the structural unit (ab) to the total structural unit (100 mol%) of the resin (X) is preferably in the range of 5 to 95 mol%, more preferably in the range of 10 to 90 mol%, and 10 to 60 mol%. Is more preferable, and the range of 10 to 40 mol% is particularly preferable.
The resin (X) having the structural unit (aa) and the structural unit (ab) in such a content ratio includes the compound (aa ′) and the compound (ab ′) with respect to the total molar amount of all monomers used in the production of the resin (X). What is necessary is just to adjust the molar amount of use.
The resin (X) may have a structural unit other than the structural unit (aa) and the structural unit (ab). Examples of such a structural unit include one or more of a structural unit derived from an acid-stable monomer described later and a structural unit having an acid-labile group described later, and in particular derived from an acid-stable monomer (a4) described later. The structural unit derived from the acid-stable monomer (a4) is particularly preferred. The content ratios of these structural units in this case can be appropriately adjusted within a range satisfying the total content ratio and the respective content ratios of the structural unit (aa) and the structural unit (ab).

<Resin (A)>
In the resist composition of the present invention, in order to obtain a synergistic effect with the acid generator regardless of the structural unit contained in the resin (X) described above, the resist composition is insoluble or hardly soluble in an aqueous alkali solution. It is preferable to contain a resin (A) that is soluble in an alkaline aqueous solution by the action of an acid.
Such a resin has a structural unit having an acid labile group (hereinafter, sometimes referred to as “structural unit (a1)”). The “acid labile group” means a hydrophilic group protected by a protecting group that can be removed by acid contact. Examples of such a hydrophilic group include a hydroxy group or a carboxy group, and a carboxy group is more preferable.
As described above, the resist composition contains a resin that has a property that is insoluble or hardly soluble in at least an aqueous alkali solution and becomes soluble in an aqueous alkali solution by the action of an acid. By using such a resist composition, A resist pattern having excellent CD uniformity can be manufactured.
Even when the resin (X) has similar characteristics, a resist pattern having excellent CD uniformity can be produced.

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を表すか、Ｒ^a1及びＲ^a2が結合して、それらが結合する炭素原子とともに炭素数３〜２０の環を形成する。Ｒ^a1及びＲ^a2が結合して形成される環及び脂肪族炭化水素基を構成するメチレン基は、酸素原子、硫黄原子又はカルボニル基に置き換わっていてもよい。＊は結合手を表す。 <Acid labile group>
In the case where the hydrophilic group is a carboxy group, the acid labile group is such that the hydrogen atom of the carboxy group is replaced by an organic residue, and the atom of the organic residue bonded to —O— of the carboxy group is a tertiary carbon atom. Certain groups (ie, esters of tertiary alcohols) can be mentioned. Among such acid labile groups, preferred acid labile groups are, for example, those represented by the following formula (1) (hereinafter sometimes referred to as “acid labile groups (1)”).

In the formula (1), R ^{a1 to} R ^a3 each independently represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, or R ^a1 and R ^a2 are bonded to each other and carbon together with the carbon atom to which they are bonded. A ring of several 3 to 20 is formed. The ring formed by combining R ^a1 and R ^a2 and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom, a sulfur atom or a carbonyl group. * Represents a bond.

このような環の炭素数は、好ましくは３〜１２である。 Examples of the ring formed by combining R ^a1 and R ^a2 in the group represented by —C (R ^a1 ) (R ^a2 ) (R ^a3 ) include the following.

The number of carbon atoms in such a ring is preferably 3-12.

Examples of the acid labile group (1) include:
1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^{a1 to} R ^a3 are all alkyl groups, and one of these alkyl groups is preferably a tert-butyl group.
),
2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are bonded to form an adamantane ring with the carbon atom to which they are bonded, and R ^a3 is an alkyl group) and 1- (adamantan-1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

式（２）中、Ｒ^b1及びＲ^b2は、それぞれ独立に、水素原子又は炭素数１〜２０の炭化水素基を表し、Ｒ^b3は、炭素数１〜２０の炭化水素基を表す。Ｒ^b2及びＲ^b3は結合して、それらが各々結合する炭素原子及び酸素原子とともに炭素数３〜２０の環を形成してもよい。該環又は該炭化水素基に含まれるメチレン基は、酸素原子、硫黄原子又はカルボニル基に置き換わっていてもよい。 Examples of the acid labile group in the case where the hydrophilic group is a hydroxy group include those in which the hydrogen atom of the hydroxy group is replaced with an organic residue to become a group containing an acetal structure or a ketal structure. Such an acid labile group is preferably, for example, one represented by the following formula (2) (hereinafter sometimes referred to as “acid labile group (2)”).

In formula (2), R ^b1 and R ^b2 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and R ^b3 represents a hydrocarbon group having 1 to 20 carbon atoms. R ^b2 and R ^b3 may combine to form a ring having 3 to 20 carbon atoms together with the carbon atom and oxygen atom to which they are bonded. The methylene group contained in the ring or the hydrocarbon group may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.

^Examples of the ring formed by combining R ^b2 and R ^b3 include those in which one carbon atom of the ring formed by combining R ^a1 and R ^a2 described above is replaced with one oxygen atom.
In Formula (2), it is preferable that at least one of R ^b1 and R ^b2 is a hydrogen atom.
Examples of the acid labile group (2) include the following groups.

The structural unit (a1) is preferably derived from a monomer having an acid labile group and a carbon-carbon double bond, more preferably derived from a (meth) acrylic monomer having an acid labile group. .
The structural unit (a1) preferably has an acid labile group (1) or an acid labile group (2), and may have both of these acid labile groups. More preferably, it has an acid labile group (1).

  Among the structural units (a1) having an acid labile group (1), it is preferable that the acid labile group (1) has a partial structure of a cyclic aliphatic hydrocarbon having 5 to 20 carbon atoms. The resin (A) having the structural unit (a1) of such a sterically bulky group is a resist having a better resolution when a resist pattern is produced using a resist composition containing the resin (A). Patterns can be manufactured.

式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−（ｋ１は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基（−ＣＯ−）との結合手である。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜１０の脂肪族炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ１’は０〜３の整数を表す。 Among the structural units (a1) having an acid labile group (1) having a partial structure of a cyclic aliphatic hydrocarbon, a structural unit represented by the formula (a1-1) (hereinafter, “structural unit ( and a structural unit represented by the formula (a1-2) (hereinafter sometimes referred to as “structural unit (a1-2)”).

In formula (a1-1) and formula (a1-2),
L ^a1 and L ^a2 each independently represent a group represented by an oxygen atom or ^* —O— (CH ₂ ) _k1 —CO—O— (k1 represents an integer of 1 to 7). * Is a bond with a carbonyl group (—CO—).
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3.

In the formula (a1-1) and the formula (a1-2), L ^a1 and L ^a2 are preferably oxygen atom or k1 is an integer of from 1 to 4 * -O- (CH _{2) k1} -CO- A group represented by O—, more preferably an oxygen atom or a group represented by * —O— (CH ₂ ) _k1 —CO—O—, wherein k1 is 1, more preferably an oxygen atom.
R ^a4 and R ^a5 are each preferably a methyl group.
R ^a6 and R ^a7 are each preferably an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms or 3 carbon atoms. -8 alicyclic hydrocarbon group, more preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 3 to 6 carbon atoms.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

Examples of the structural unit represented by the formula (a1-1) include the following.

  In the specific example of the structural unit (a1-1) represented by any one of the formulas (a1-1-1) to (a1-1-38), the partial structure is similar to the specific example of the structural unit (aa). What substituted (Mc) by the partial structure (Ac) can also be mentioned as a specific example of the structural unit (a1-1).

  Among the examples of the structural unit (a1-1), the structural unit (a1−1) represented by any one of the formula (a1-1-1), the formula (a1-1-2), and the formula (a1-1-3) 1) and those obtained by substituting the partial structure (Mc) of these structural units (a1-1) with the partial structure (Ac) are also preferred, and are represented by the formulas (a1-1-1), (a1-1-2) and The structural unit (a1-1) represented by any one of the formula (a1-1-3) is more preferable, and is represented by any one of the formula (a1-1-1) and the formula (a1-1-2). The structural unit (a1-1) is more preferable. In addition, the resin (A) having these preferred structural units (a1-1) is obtained by producing 2-methyladamantan-2-yl (meth) acrylate, 2-ethyladamantan-2-yl when producing the resin (A). Ir (meth) acrylate or 2-isopropyladamantan-2-yl (meth) acrylate or the like may be used as a raw material (monomer) for production.

Examples of the structural unit represented by the formula (a1-2) include the following.

  In the specific example of the structural unit (a1-2) represented by any one of the formulas (a1-2-1) to (a1-2-12), the partial structure is similar to the specific example of the structural unit (aa). What substituted (Mc) by the partial structure (Ac) can also be mentioned as a specific example of the structural unit (a1-2).

  Among them, the structural unit (a1-2-1), the formula (a1-2-2), the formula (a1-2-4), and the formula (a1-2-5) represented by any one of the formulas (a1-2-1), (a1-2-2), (a1-2-5) 2) or those obtained by substituting the partial structure (Mc) of these structural units (a1-2) with the partial structure (Ac) are more preferable. More preferably, the structural unit represented by any one of 5) or the partial structure (Mc) of these structural units (a1-2) is replaced with the partial structure (Ac). In order to produce the resin (A) having such a structural unit (a1-2), 1-ethylcyclohexane-1-yl (meth) acrylate or the like may be used as a monomer.

When the resin (A) having the structural unit (a1-1) and / or the structural unit (a1-2) is produced, when the total structural unit of the resin (A) is 100 mol%, the structural unit (a1-1) ) And / or the total content of the structural unit (a1-2) is preferably in the range of 10 to 95 mol%, more preferably in the range of 15 to 90 mol%, and still more preferably in the range of 20 to 85 mol%. In order to make the total content of the structural unit (a1-1) and / or the structural unit (a1-2) within such a range, when the resin (A) is produced, What is necessary is just to adjust the usage-amount of the monomer which induces | guides | derives a structural unit (a1-1) and / or a structural unit (a1-2).
Moreover, when manufacturing resin (X) which has structural unit (a1-1) and / or structural unit (a1-2), when all the structural units of resin (X) are 100 mol%, structural unit The total content of (a1-1) and / or the structural unit (a1-2) is preferably in the range of 10 to 95 mol%, more preferably in the range of 15 to 90 mol%, and in the range of 20 to 85 mol%. Even more preferred. In order to achieve such a range, the use amount of the monomer for deriving the structural unit (a1-1) and / or the structural unit (a1-2) and the total use of the compound (aa ′) and the compound (ab ′) What is necessary is just to adjust the ratio with quantity.

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のアルキル基、カルボキシル基、シアノ基又は基−ＣＯＯＲ^a13（ここで、Ｒ^a13は、炭素数１〜２０の脂肪族炭化水素基を表し、該脂肪族炭化水素基を構成する水素原子は、ヒドロキシ基に置換されていてもよく、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい）を表す。
Ｒ^a10〜Ｒ^a12は、それぞれ独立に、炭素数１〜２０の脂肪族炭化水素基を表すか、或いは、Ｒ^a10及びＲ^a11が結合して、これらが結合している炭素原子とともに、炭素数３〜２０の環を形成し、脂肪族炭化水素基及び環を構成する水素原子は、ヒドロキシ基などで置換されていてもよく、該脂肪族炭化水素基及び環を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。 In addition to structural units derived from (meth) acrylic monomers such as structural unit (a1-1) and structural unit (a1-2), the resin includes acid labile groups (1) and carbon-carbon doubles. Other structural units having a bond in the molecule may be included.
Examples of the monomer for deriving another structural unit include a monomer having a norbornene ring represented by the following formula (a1-3) (hereinafter sometimes referred to as “monomer (a1-3)”).

In formula (a1-3),
R ^a9 is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms which may have a hydroxy group, a carboxyl group, a cyano group or a group —COOR ^a13 (where R ^a13 is an aliphatic group having 1 to 20 carbon atoms) Represents a hydrocarbon group, and the hydrogen atom constituting the aliphatic hydrocarbon group may be substituted with a hydroxy group, and the methylene group constituting the aliphatic hydrocarbon group is replaced with an oxygen atom or a carbonyl group. May be present).
R ^{a10 to} R ^a12 each independently represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or R ^a10 and R ^a11 are bonded to each other together with the carbon atom to which these are bonded, The aliphatic hydrocarbon group and the hydrogen atom constituting the ring forming a ring of 3 to 20 may be substituted with a hydroxy group or the like, and the methylene group constituting the aliphatic hydrocarbon group and the ring is oxygen An atom or a carbonyl group may be substituted.

  Examples of the alkyl group having a hydroxy group include a hydroxymethyl group and a 2-hydroxyethyl group.

In formula (a1-3), R ^a13 is preferably an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms.
The ring formed by combining R ^a10 and R ^a11 with each other is preferably an alicyclic hydrocarbon, and specifically, a cyclohexane ring and an adamantane ring are more preferable.

  As the monomer (a1-3), for example, 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene-2-carboxylic acid 1 -Methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl, 5-norbornene-2-carboxylic acid 1- (4-methyl) Cyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1- (4-oxocyclohexyl) Ethyl and 5-norbornene-2-carboxylic acid 1- (1-adamantyl) -1-methyl Ethyl and the like.

  When the resin (A) is produced using the monomer (a1-3), the resin (A) includes a sterically bulky structural unit derived from the monomer (a1-3). Thus, if a resist pattern is manufactured with the resist composition containing resin (A) which has a three-dimensionally bulky structural unit, a resist pattern can be obtained with a better resolution. Furthermore, since a rigid norbornane ring can be introduced into the main chain of the resin (A) by using the monomer (a1-3), the resist composition containing the resin (A) has a resist pattern with excellent dry etching resistance. There is a tendency to be easily obtained.

In the case where the resin (A) has a structural unit derived from the monomer (a1-3) from the viewpoint that a resist pattern can be produced with good resolution and a resist pattern excellent in dry etching resistance can be obtained, the resin (A ) To the total structural unit (100 mol%), the content is preferably in the range of 10 to 95 mol%, more preferably in the range of 15 to 90 mol%, and still more preferably in the range of 20 to 85 mol%.
When the resin (X) has a structural unit derived from the monomer (a1-3), the content is in the range of 10 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (X). Is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is further more preferable.

式（ａ１−４）中、
Ｒ^a32は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｒ^a33は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル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以上である場合、複数のＲ^a33はそれぞれ独立である。
Ｒ^a34及びＲ^a35は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表す。
Ｘ^a2は、単結合又は置換基を有していていもよい炭素数１〜１７の脂肪族炭化水素基を表し、該脂肪族炭化水素基を構成するメチレン基は、酸素原子、硫黄原子、カルボニル基、スルホニル基又は−Ｎ（Ｒ^ｃ）−で示される基に置き換わっていてもよい。ここで、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、置換基を有していてもよい炭素数１〜１８の炭化水素基である。 Examples of the monomer having an acid labile group (2) include a monomer represented by the following formula (a1-4) (hereinafter sometimes referred to as “monomer (a1-4)”).

In formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyl group, or methacryloyl. Represents a group.
la represents an integer of 0 to 4. When la is 2 or more, the plurality of R ^a33 are each independent.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
X ^a2 represents a C 1-17 aliphatic hydrocarbon group which may have a single bond or a substituent, and the methylene group constituting the aliphatic hydrocarbon group includes an oxygen atom, a sulfur atom, a carbonyl A group, a sulfonyl group or a group represented by -N (R ^c )-may be substituted. Here, R ^c represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Y ^a3 is an ^optionally substituted hydrocarbon group having 1 to 18 carbon atoms.

  Examples of the alkyl group having a halogen atom include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluorohexyl. Haloalkyl groups such as groups, trichloromethyl groups, tribromomethyl groups and triiodomethyl groups.

As an alkyl group, a C1-C4 alkyl group is preferable, a methyl group and an ethyl group are more preferable, and a methyl group is especially preferable.
As the alkoxy group, a methoxy group and an ethoxy group are more preferable, and a methoxy group is particularly preferable.
The aliphatic hydrocarbon group for X ^a2 is preferably a chain aliphatic hydrocarbon group, more preferably a saturated aliphatic hydrocarbon group, and still more preferably an alkyl group.
The hydrocarbon group for Y ^a3 is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
Of hydrocarbon groups R ^a34 and R ^a35, as the chain aliphatic hydrocarbon group, an isopropyl group, n- butyl group, sec- butyl group, tert- butyl group, a pentyl group, a hexyl group, an octyl group and 2 -Ethylhexyl group is preferable, and examples of the alicyclic hydrocarbon group include cyclohexyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group and isobornyl group. As the aromatic hydrocarbon group, phenyl group, naphthyl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl Group, anthryl group, phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-ethylpheny And the like are preferable.
The substituent in X ^a2 is preferably a group selected from the group consisting of a halogen atom, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, and an acyloxy group having 2 to 4 carbon atoms. More preferably a hydroxy group.
The substituent in Y ^a3 is preferably 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, or an acyloxy group having 2 to 4 carbon atoms. Group, more preferably a hydroxy group.

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

In the monomer (a1-4) shown here, the partial structure (V ′) shown below can be replaced with the partial structure (P ′) as a specific example of the monomer (a1-4).

When the resin (A) has a structural unit derived from the monomer (a1-4), the content ratio is in the range of 10 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (A). Is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is further more preferable.
When the resin (X) has a structural unit derived from the monomer (a1-4), the content ratio is in the range of 10 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (X). Is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is further more preferable.

[式（ａ１−５）中、
Ｒ^３１は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｌ^１〜Ｌ^３は、オキシ基、チオキシ基又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−で表される基を表す。ここで、ｋ１は１〜７の整数を表し、＊はカルボニル基（−ＣＯ−）との結合手である。
Ｚ^１は、単結合又は炭素数１〜６のアルカンジイル基であり、該アルカンジイル基中に含まれるメチレン基は、オキシ基又はカルボニル基に置き換わっていてもよい。
ｓ１及びｓ１’は、それぞれ独立して、０〜４の整数を表す。] As the monomer having an acid labile group (2), a (meth) acrylic monomer is preferable. For example, the monomer represented by the formula (a1-5) (hereinafter sometimes referred to as “monomer (a1-5)”) There is).

[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.
L ^{1 to} L ³ represent a group represented by an oxy group, a thioxy group, or ^* —O— (CH ₂ ) _k1 —CO—O—. Here, k1 represents an integer of 1 to 7, and * is a bond with a carbonyl group (—CO—).
Z ¹ is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group contained in the alkanediyl group may be replaced with an oxy group or a carbonyl group.
s1 and s1 ′ each independently represents an integer of 0 to 4. ]

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

As a monomer (a1-5), the following monomers are mentioned, for example. Here, specific examples R ³¹ is a methyl group, and replaces the methyl group to a hydrogen atom, a specific example of the monomer (a1-5).

上記モノマーにおいて、Ｒ³¹に相当するメチル基が水素原子に置き換わったモノマーも、モノマー（ａ１−５）の具体例として挙げることができる。

In the above monomer, a monomer in which the methyl group corresponding to R ³¹ is replaced with a hydrogen atom can also be mentioned as a specific example of the monomer (a1-5).

When the resin (A) has a structural unit derived from the monomer (a1-5), the content is in the range of 10 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (A). Is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is further more preferable.
When the resin (X) has a structural unit derived from the monomer (a1-5), the content ratio is in the range of 10 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (X). Is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is further more preferable.

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

When the resin (A) has a structural unit derived from another acid labile monomer, the content is preferably 10 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (A). It is a range, More preferably, it is 15-90 mol%, More preferably, it is 20-85 mol%.
When the resin (X) has a structural unit derived from another acid labile monomer, the content is preferably 10 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (X). It is a range, More preferably, it is 15-90 mol%, More preferably, it is 20-85 mol%.

In the resin (A), when a monomer having an adamantyl group (particularly, the monomer (a1-1)) is used as the monomer (a1), the adamantyl is used with respect to the total amount (100 mol%) of the monomer (a1) used. The amount of the monomer having a group is preferably 15 mol% or more. By setting it as this range, there exists a tendency for the dry etching tolerance of the resist pattern obtained from the resist composition containing resin (A) to become more favorable.
In addition, when determining the content ratio of the acid stable structural unit on the basis of the content ratio of the structural unit (a1), the content ratio includes the structural unit (aa) and the structural unit (ab) in the acid stable structural unit. Should be calculated.

<Acid stable structural unit>
In the resist composition of the present invention, the resin (A) to be used has a structural unit having no acid labile group (hereinafter sometimes referred to as “acid-stable structural unit”) in addition to the structural unit (a1). It is preferable.
The acid stable structural unit is suitably determined based on the content ratio of the structural unit (a1). The ratio between the content of the structural unit (a1) and the content of the acid-stable structural unit (a2) is represented by [structural unit (a1)] / [acid-stable structural unit], preferably 10 to 80 mol%. / 90 to 20 mol%, more preferably 20 to 60 mol% / 80 to 40 mol%.

  The acid stable structural unit is preferably a structural unit having a hydroxy group or a lactone ring. Resin having an acid stable structural unit having a hydroxy group (hereinafter referred to as “acid stable structural unit (a2)”) and / or an acid stable structural unit having a lactone ring (hereinafter referred to as “acid stable structural unit (a3)”) (A) shows that when a resist composition containing such a resin (A) is applied to a substrate, a coating film formed on the substrate or a composition layer obtained from the coating film is excellent between the substrate and the substrate. It becomes easy to express adhesiveness, and a resist pattern can be manufactured with good resolution.

<Acid stable structural unit (a2)>
When the acid stable structural unit (a2) is introduced into the resin (A), depending on the type of exposure source used when producing a resist pattern from the resist composition containing the resin (A), a suitable acid stable structural unit ( 1 type (s) or 2 or more types can be selected for a2).
For example, when the resist composition is used for exposure using a KrF excimer laser (wavelength: 248 nm) as an exposure source, or exposure using a high energy beam such as an electron beam or EUV light as an exposure source, the acid stable structural unit (a2 ), It is preferable to introduce an acid stable structural unit (a2-0) having a phenolic hydroxy group into the resin (A).
When using exposure using a short wavelength ArF excimer laser (wavelength: 193 nm) as an exposure source, an acid stable structural unit represented by the formula (a2-1) described later is used as a resin ( It is preferable to introduce into A).

式（ａ２−１）中、
Ｌ^a3は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−（ｋ２は１〜７の整数を表す。）を表し、＊はカルボニル基（−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。 <Acid stable structural unit (a2-1)>
Examples of the acid stable structural unit (a2) include those represented by the following formula (a2-1) (hereinafter sometimes referred to as “acid stable structural unit (a2-1)”).

In formula (a2-1),
L ^a3 represents an oxygen atom or ^* —O— (CH ₂ ) _k2 —CO—O— (k2 represents an integer of 1 to 7), and * represents a bond with a carbonyl group (—CO—). Represent.
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 an oxygen atom or a group that k2 is represented there _{-O- (CH 2) k2 -CO-} O- in an integer of from 1 to 4, more preferably, an oxygen atom or, -O-CH ₂ -CO-O- and, still more preferably an oxygen atom.
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 structural unit (a2-1), the following are mentioned, for example.

式（ａ２−１−１）〜式（ａ２−１−１７）のいずれかで表される酸安定構造単位（ａ２−１）の具体例において、構造単位（ａａ）の具体例と同様に、部分構造（Ｍｃ）を部分構造（Ａｃ）に置き換えたものも酸安定構造単位（ａ２−１）の具体例として挙げることができる。

In the specific example of the acid stable structural unit (a2-1) represented by any one of the formula (a2-1-1) to the formula (a2-1-17), as in the specific example of the structural unit (aa), What substituted the partial structure (Mc) by the partial structure (Ac) can also be mentioned as a specific example of an acid stable structural unit (a2-1).

  Among the acid stable structural units (a2-1), any one of the formula (a2-1-1), the formula (a2-1-2), the formula (a2-1-13) and the formula (a2-1-15) The acid stable structural unit (a2-1) represented by the formula (a2-1) and the partial structure (Mc) of these acid stable structural units (a2-1) are preferably replaced by the partial structure (Ac). 1-1), the acid stable structural unit (a2-1) represented by any one of formula (a2-1-2), formula (a2-1-13) and formula (a2-1-15) is more preferable. . Resin (A) which has these acid stable structural units (a2-1) is 3-hydroxyadamantan-1-yl (meth) acrylate, 3,5-dihydroxyadamantan-1-yl (meth) acrylate or (meth) What is necessary is just to use acrylic acid 1- (3,5-dihydroxyadamantane-1-yloxycarbonyl) methyl etc. as a monomer for resin (A) manufacture.

When the resin (A) has an acid stable structural unit (a2-1), the content ratio is preferably in the range of 3 to 40 mol% with respect to all the structural units (100 mol%) of the resin (A). The range of 5 to 35 mol% is more preferable, and the range of 5 to 30 mol% is more preferable.
When the resin (X) has a structural unit derived from a structural unit derived from the acid-stable monomer (a2-1), the content ratio is based on the total structural unit (100 mol%) of the resin (X). The range of 1 to 90 mol% or less is preferable, the range of 10 to 80 mol% is more preferable, and the range of 20 to 70 mol% is more preferable.

式（ａ２−０）中、
Ｒ^a30は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^a31は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル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^a31はそれぞれ独立である。 <Acid stable structural unit (a2-0)>
Examples of the acid stable structural unit (a2) include those represented by the following formula (a2-0) (hereinafter sometimes referred to as “acid stable structural unit (a2-0)”).

In formula (a2-0),
R ^a30 represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
R ^a31 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an 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 ^a31 are independent of each other.

In Formula (a2-0), R ^a30 is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.
As the alkyl group for R ^a31 , an alkyl group having 1 to 4 carbon atoms is preferable, an alkyl group having 1 or 2 carbon atoms is more preferable, and a methyl group is particularly preferable.
R ^a31 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and particularly preferably a methoxy group.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.

ここに例示する具体例において、ベンゼン環に結合しているメチル基やエチル基を、Ｒ^a31として例示したその他の置換基に置き換えたものも、酸安定モノマーの具体例である。 Examples of the monomer that gives the acid stable structural unit (a2-0) include the following monomers.

In the specific examples exemplified here, those in which the methyl group or ethyl group bonded to the benzene ring is replaced with other substituents exemplified as ^Ra31 are also specific examples of the acid stable monomer.

  When the resin (A) is produced using such an acid-stable monomer, a monomer in which a phenolic hydroxy group in this acid-stable monomer is protected with an appropriate protecting group can also be used. As the protecting group, for example, a protecting group capable of leaving with an acid or a base is preferable. The phenolic hydroxy group protected with a protecting group capable of leaving with an acid or a base is deprotected by contact with an acid or a base, whereby an acid stable structural unit (a2-0) is obtained. However, since the resin (A) has the structural unit (a1) having an acid labile group as described above, the acid labile group of the structural unit (a1) is not significantly impaired when deprotecting. Thus, it is preferable to deprotect by contact with a base. As the protective group, for example, an acetyl group, a benzoyl group and the like are preferable. Examples of the base include 4-dimethylaminoviridine, triethylamine and the like.

  As the above acid-stable monomer (a2-0), 4-hydroxystyrene or 4-hydroxy-α-methylstyrene is particularly preferable. When using these, when manufacturing resin (A), what protected the phenolic hydroxy group in these with the suitable protective group can also be used.

When the resin (A) has an acid stable structural unit (a2-0), the content is preferably in the range of 5 to 95 mol% with respect to all the structural units (100 mol%) of the resin (A). The range of 10-80 mol% is more preferable, and the range of 15-80 mol% is more preferable.
When the resin (X) has a structural unit derived from the acid-stable monomer (a2-0), the content is 90 mol% or less with respect to the total structural unit (100 mol%) of the resin (X). The range is preferable, the range of 10 to 80 mol% is more preferable, and the range of 20 to 70 mol% is more preferable.

<Acid stable structural unit (a3)>
The lactone ring included in the acid stable structural unit (a3) may be monocyclic such as β-propiolactone ring, γ-butyrolactone ring and δ-valerolactone ring, and the monocyclic lactone ring and other It may be a condensed ring with a ring. 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 structural unit (a3) is preferably one represented by the following formula (a3-1), formula (a3-2) or formula (a3-3). Resin (A) may have only 1 type among these, and may have 2 or more types. In the following description, what is represented by the formula (a3-1) is referred to as “acid-stable structural unit (a3-1)”, and what is represented by the formula (a3-2) is “acid-stable structural unit ( a3-2) ”, and the compound represented by formula (a3-3) may be referred to as“ acid-stable structural unit (a3-3) ”.

［式（ａ３−１）〜式（ａ３−３）中、
Ｌ^a4〜Ｌ^a6は、それぞれ独立して、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す）を表す。＊はカルボニル基との結合手を表す。
Ｒ^a18〜Ｒ^a20は、それぞれ独立して、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し、ｐ１が２以上の場合、複数のＲ^a21はそれぞれ独立である。
Ｒ^a22及びＲ^a23は、それぞれ独立して、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し、ｑ１が２以上の場合、複数のＲ^a22は、それぞれ独立であり、ｒ１が２以上の場合、複数のＲ^a23は、それぞれ独立である。
ｐ１は、０〜５の整数を表す。
ｑ１は、０〜３の整数を表す。
ｒ１は、０〜３の整数を表す。］

[In Formula (a3-1)-Formula (a3-3),
L ^{a4 to} L ^a6 each independently represent an oxygen atom or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
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, and when p1 is 2 or more, the plurality of R ^a21 are independent of each other.
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, and when q1 is 2 or more, a plurality of R ^a22 are each independent, When r1 is 2 or more, the plurality of R ^a23 are each independent.
p1 represents an integer of 0 to 5.
q1 represents an integer of 0 to 3.
r1 represents an integer of 0 to 3. ]

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 each independently represent an oxygen atom or * —O— (CH ₂ ) _k3 —CO in which k3 is an integer of 1 to 4. A group represented by —O— is preferable, an oxygen atom or * —O—CH ₂ —CO—O— is more preferable, and an oxygen atom is more preferable.
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 preferably integers of 0 to 2, more preferably 0 or 1.

Examples of the acid stable structural unit (a3-1) include the following.

Examples of the acid stable structural unit (a3-2) include the following.

式（ａ３−１−１）〜式（ａ３−１−１１）のいずれかで表される酸安定構造単位（ａ３−１）、式（ａ３−２−１）〜式（ａ３−２−１１）のいずれかで表される酸安定構造単位（ａ３−２）及び式（ａ３−３−１）〜式（ａ３−３−６）のいずれかで表される酸安定構造単位（ａ３−３）において、構造単位（ａａ）の例示と同様に、部分構造（Ｍｃ）を部分構造（Ａｃ）に置き換えたものも、各々酸安定構造単位（ａ３−１）、酸安定構造単位（ａ３−２）及び酸安定構造単位（ａ３−３）の具体例として挙げることができる。また、この例示において、ラクトン環が有する置換基（Ｒ^a21〜Ｒ^a23）としてメチル基を有するものも例示したが、このメチル基を上述のような基に置き換えたものも、酸安定構造単位（ａ３）の具体例として挙げられる。 Examples of the acid stable structural unit (a3-3) include the following.

The acid stable structural unit (a3-1) represented by any one of formula (a3-1-1) to formula (a3-1-11), formula (a3-2-1) to formula (a3-2-11) The acid stable structural unit (a3-2) represented by any one of the formula (a3-3-1) and the acid stable structural unit (a3-3) represented by any one of the formulas (a3-3-1) to (a3-3-6) In the same manner as in the structural unit (aa), the partial structure (Mc) is replaced by the partial structure (Ac), and the acid stable structural unit (a3-1) and the acid stable structural unit (a3-2) ) And acid stable structural unit (a3-3). Moreover, in this illustration, those having a methyl group as an example of the substituent (R ^{a21 to} R ^a23 ) of the lactone ring are also exemplified, but those in which this methyl group is replaced with the above-described groups are also acid stable structural units ( Specific examples of a3) are mentioned.

Among the acid stable structural units (a3), α- (meth) acryloyloxy-γ-butyrolactone, β- (meth) acryloyloxy-γ-butyrolactone, α- (meth) acryloyloxy-β, β-dimethyl-γ-butyrolactone, α -(Meth) acryloyloxy-α-methyl-γ-butyrolactone, β- (meth) acryloyloxy-α-methyl-γ-butyrolactone, (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1 .0 ^3,7] nonane-2-yl, (meth) acrylic acid 2- tetrahydro-2-oxo-3-furyl, and (meth) acrylic acid (5-oxo-4-oxa-tricyclo [4.2.1 .0 ^3,7] nonane-2-yloxy) -2-oxoethyl acid derived from such stable structural unit (a3) is preferable.

The resin (A) has an acid stable structural unit (a3) selected from the group consisting of an acid stable structural unit (a3-1), an acid stable structural unit (a3-2), and an acid stable structural unit (a3-3). In this case, the total content is preferably in the range of 5 to 70 mol%, more preferably in the range of 10 to 65 mol%, and more preferably 10 to 60 mol, based on the total structural unit (100 mol%) of the resin (A). % Range is more preferred. The content of each of the acid stable structural unit (a3-1), the acid stable structural unit (a3-2), and the acid stable structural unit (a3-3) is the total structural unit (100 mol%) of the resin (A). On the other hand, the range of 5-60 mol% is preferable, the range of 10-55 mol% is more preferable, the range of 20-50 mol% is more preferable, and the range of 20-45 mol% is still more preferable.
When the resin (X) has an acid stable structural unit (a3), the total content is preferably in the range of 1 to 90 mol% with respect to the total structural units (100 mol%) of the resin (X). The range of 10-80 mol% is more preferable, and the range of 20-70 mol% is further more preferable.

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のアルキル基、シアノ基、カルボキシ基又は基−ＣＯＯＲ^a27（ここで、Ｒ^a27は、炭素数１〜１８の脂肪族炭化水素基を表し、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。但し−ＣＯＯＲ^a27が酸不安定基となるものは除く（例えば、Ｒ^a27は、第三級炭素原子が−Ｏ−と結合するものを含まない））を表すか、或いはＲ^a25及びＲ^a26が結合して−ＣＯ−Ｏ−ＣＯ−を形成する。 <Acid-stable monomer (a4)>
The resin (A) may have a structural unit derived from a monomer that derives another acid stable structural unit (hereinafter sometimes referred to as “acid stable monomer (a4)”). The structural unit derived from the acid stable monomer (a4) is preferably contained in the resin (X).
As the acid stable monomer (a4), maleic anhydride represented by the following formula (a4-1), itaconic anhydride represented by the formula (a4-2) and norbornene represented by the formula (a4-3) Examples thereof include an acid-stable monomer having a ring (hereinafter sometimes referred to as “acid-stable monomer (a4-3)”).

In formula (a4-3),
R ^a25 and R ^a26 each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms which may have a hydroxy group, a cyano group, a carboxy group or a group —COOR ^a27 (wherein R ^a27 represents ^{Represents a C1-C18} aliphatic hydrocarbon group, and the methylene group constituting the aliphatic hydrocarbon group may be replaced by an oxygen atom or a carbonyl group, provided that -COOR ^a27 is an acid labile group. (For example, R ^a27 does not include those in which a tertiary carbon atom is bonded to —O—)), or R ^a25 and R ^a26 are bonded to form —CO—O—CO—. Form.

As the alkyl group which may have a hydroxy group, a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, a 2-hydroxyethyl group and the like are preferable.
The aliphatic hydrocarbon group is preferably an alkyl group having 1 to 8 carbon atoms and an alicyclic hydrocarbon group having 4 to 18 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms and 4 to 12 carbon atoms. And a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, a 2-oxo-oxolan-4-yl group, and the like are more preferable.

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

The resin (A) is a structural unit derived from maleic anhydride represented by the formula (a4-1), a structural unit derived from itaconic anhydride represented by the formula (a4-2), and a monomer (a4-3). In the case of having a structural unit selected from the group consisting of structural units derived from, the total content is preferably in the range of 2 to 40 mol% with respect to all structural units (100 mol%) of the resin (A), The range of 3-30 mol% is more preferable, and the range of 5-20 mol% is more preferable.
Resin (X) is a structure derived from a structural unit derived from a monomer represented by formula (a4-1), a monomer represented by formula (a4-2), or a monomer represented by formula (a4-3) When it has a unit, the content ratio is preferably in the range of 40 mol% or less, more preferably in the range of 3 to 30 mol%, and more preferably in the range of 5 to 20 with respect to the total structural unit (100 mol%) of the resin (X) A range of mol% is more preferable.

式（ａ４−４）中、
Ｌ^a7は、酸素原子又は^＊−Ｔ−（ＣＨ₂）_k2−ＣＯ−Ｏ−を（ｋ２は１〜７の整数を表す。Ｔは酸素原子又はＮＨである。）表し、＊はカルボニル基との結合手を表す。
Ｒ^a28は、水素原子又はメチル基を表す。
Ｗ¹⁰は、置換基を有していてもよいスルトン環基を表す。］ Furthermore, examples of the acid stable monomer (a4) include those having a sultone ring represented by the formula (a4-4) (hereinafter may be referred to as “acid stable monomer (a4-4)”). .

In formula (a4-4),
L ^a7 represents an oxygen atom or ^* -T— (CH ₂ ) _k2 —CO—O— (k2 represents an integer of 1 to 7. T is an oxygen atom or NH), and * represents a carbonyl group Represents the bond hand.
R ^a28 represents a hydrogen atom or a methyl group.
W ¹⁰ represents a sultone ring group which may have a substituent. ]

スルトン環基に置換され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のアシル基及び炭素数１〜８のアシルオキシ基からなる群より選ばれる。 As the sultone ring contained in the sultone ring group, one of the adjacent methylene groups contained in the alicyclic hydrocarbon is replaced with an oxygen atom and the other is replaced with a sulfonyl group, that is, -O-SO _{2 in the} ring skeleton. Examples of the ring include-and those shown below. A typical example of the sultone ring group is one in which one of the hydrogen atoms in the sultone ring shown below is replaced with a bond, and in the formula (a4-4), the bond with L ^a7 corresponds.

Examples of the substituent which may be substituted on the sultone ring group include 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, and a hydroxyalkyl group having 1 to 6 carbon atoms. , 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.

As an acid stable monomer (a4-4), what is represented by the following is mentioned, for example.

ここに示した酸安定モノマー（ａ４−４）の具体例において、部分構造（Ｍｃ’）を部分構造（Ａｃ’）に置き換えたものも、酸安定モノマー（ａ４−４）の具体例として挙げることができる。

In the specific examples of the acid-stable monomer (a4-4) shown here, those in which the partial structure (Mc ′) is replaced with the partial structure (Ac ′) are also exemplified as specific examples of the acid-stable monomer (a4-4). Can do.

When the resin (A) has a structural unit derived from the acid-stable monomer (a4-4), the content is 2 to 40 mol% with respect to the total structural unit (100 mol%) of the resin (A). The range is preferably 3 to 35 mol%, more preferably 5 to 30 mol%.
When the resin (X) has a structural unit derived from the acid-stable monomer (a4-4), the content is 40 mol% or less with respect to the total structural unit (100 mol%) of the resin (X). The range is preferable, the range of 3 to 35 mol% is more preferable, and the range of 5 to 30 mol% is more preferable.

The acid stable monomer (a4) may be, for example, a monomer having a fluorine atom as shown below [hereinafter sometimes referred to as “acid stable monomer (a4-5)]”.

Among such acid stable monomers (a4-5), (meth) acrylic acid 5- (3,3,3-trifluoro-2-hydroxy-2- [2-] having monocyclic or polycyclic hydrocarbons. Trifluoromethyl] propyl) bicyclo [2.2.1] hept-2-yl, 6- (3,3,3-trifluoro-2-hydroxy-2- [trifluoromethyl] propyl (meth) acrylate) Bicyclo [2.2.1] hept-2-yl and 4,4-bis (trifluoromethyl) -3-oxatricyclo [4.2.1.0 ^2,5 ] nonyl (meth) acrylate are preferred. .

When the resin (A) has a structural unit derived from the acid-stable monomer (a4-5), the total content is 1 to 20 mol relative to the total structural unit (100 mol%) of the resin (A). % Range is preferable, the range of 2-15 mol% is more preferable, and the range of 3-10 mol% is more preferable.
When the resin (X) has a structural unit derived from the acid-stable monomer (a4-5), the content ratio is 20 mol% or less with respect to the total structural unit (100 mol%) of the resin (X). The range is preferable, the range of 2 to 15 mol% is more preferable, and the range of 3 to 10 mol% is more preferable.

式（３）中、
Ｒ¹⁰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。 Furthermore, as another acid stable monomer (a4), the monomer which has group represented by the following formula | equation (3) is mentioned (henceforth "acid stable monomer (a4-6)" depending on the case).

In formula (3),
R ¹⁰ represents a fluorinated alkyl group having 1 to 6 carbon atoms. * Represents a bond.

In the formula (3), the fluorinated alkyl group represented by R ¹⁰ preferably has 1 to 4 carbon atoms, more preferably a trifluoromethyl group, a perfluoroethyl group, and a perfluoropropyl group, and particularly preferably a perfluoromethyl group. .

As an acid stable monomer (a4-6), what is represented by the following is mentioned, for example.

ここに示した酸安定モノマー（ａ４−６）の具体例において、酸安定モノマー（ａ４−４）の例示と同様に、部分構造（Ｍｃ’）を部分構造（Ａｃ’）に置き換えたものも、酸安定モノマー（ａ４−６）の具体例として挙げることができる。

In the specific example of the acid stable monomer (a4-6) shown here, as in the case of the acid stable monomer (a4-4), the partial structure (Mc ′) is replaced with the partial structure (Ac ′). Specific examples of the acid stable monomer (a4-6) can be given.

When the resin (A) has a structural unit derived from the acid stable monomer (a4-6), the content is 5 to 90 mol% with respect to the total structural unit (100 mol%) of the resin (A). The range is preferably 10 to 80 mol%, more preferably 20 to 70 mol%.
When the resin (X) has a structural unit derived from the acid-stable monomer (a4-6), the content is 90 mol% or less with respect to the total structural unit (100 mol%) of the resin (X). The range is preferable, the range of 10 to 80 mol% is more preferable, and the range of 20 to 70 mol% is more preferable.

式（４）中、
Ｒ¹¹は、置換基を有してもよい炭素数６〜１２の芳香族炭化水素基を表す。
Ｒ¹²は、置換基を有してもよい炭素数１〜１２の炭化水素基を表し、該炭化水素基は、ヘテロ原子を含んでいてもよい。
Ａ^３は、単結合、−（ＣＨ_２）_ｍ10−ＳＯ_２−Ｏ−＊又は−（ＣＨ_２）_ｍ10−ＣＯ−Ｏ−＊を表し、ここに示すアルカンジイル鎖〔−（ＣＨ_２）_ｍ10−〕を構成するメチレン基は、酸素原子、カルボニル基又はスルホニル基に置き換わっていてもよく、当該アルカンジイル鎖に含まれる水素原子は、フッ素原子に置き換わっていてもよい。
ｍ１０は、１〜１２の整数を表す。 The acid stable monomer (a4) may have a group represented by the following formula (4).

In formula (4),
R ¹¹ represents an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent.
R ¹² represents an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, and the hydrocarbon group may contain a hetero atom.
A ³ represents a single bond, — (CH ₂ ) _{m 10} —SO ₂ —O— * or — (CH ₂ ) _{m 10} —CO—O— *, and the alkanediyl chain shown here [— (CH ₂ ) _{m 10} − ] May be replaced with an oxygen atom, a carbonyl group or a sulfonyl group, and a hydrogen atom contained in the alkanediyl chain may be replaced with a fluorine atom.
m10 represents an integer of 1 to 12.

As the substituent of the aromatic hydrocarbon group in R ¹¹ , an alkyl group having 1 to 4 carbon atoms, a halogen atom, a phenyl group, a nitro group, a cyano group, a hydroxy group, a phenyloxy group, and a tert-butylphenyl group are preferable. .

Examples of R ¹¹ include the following groups.

Examples of the hetero atom that the hydrocarbon in R ¹² may contain include a halogen atom, a sulfur atom, an oxygen atom, and a nitrogen atom. Moreover, the form containing a sulfonyl group and a carbonyl group as a coupling group may be sufficient.
Examples of R ¹² containing such a heteroatom include the following groups.

Examples of A ³ include the following groups.

式（ａ４−７）中、
Ｒ¹³は、水素原子又はメチル基を表す。
Ｒ¹¹、Ｒ¹²及びＡ^３は、前記と同義である。 As the acid stable monomer (a4) containing a group represented by the formula (4), for example, a monomer represented by the formula (a4-7) (hereinafter sometimes referred to as “acid stable monomer (a4-7)”) Is mentioned.

In formula (a4-7),
R ¹³ represents a hydrogen atom or a methyl group.
R ¹¹ , R ¹² and A ³ are as defined above.

ここに示した酸安定モノマー（ａ４−７）の具体例において、酸安定モノマー（ａ４−４）の具体例と同様に、部分構造（Ｍｃ’）を部分構造（Ａｃ’）に置き換えたものも、酸安定モノマー（ａ４−７）の具体例として挙げることができる。 Examples of the acid stable monomer (a4-7) include the following.

In the specific example of the acid stable monomer (a4-7) shown here, as in the specific example of the acid stable monomer (a4-4), the partial structure (Mc ′) is replaced with the partial structure (Ac ′). Specific examples of the acid-stable monomer (a4-7) can be given.

When the resin (A) has a structural unit derived from the acid-stable monomer (a4-7), the content is 5 to 90 mol% with respect to the total structural unit (100 mol%) of the resin (A). The range is preferably 10 to 80 mol%, more preferably 20 to 70 mol%.
When the resin (X) has a structural unit derived from the acid-stable monomer (a4-7), the content is 90 mol% or less with respect to the total structural unit (100 mol%) of the resin (X). The range is preferable, the range of 10 to 80 mol% is more preferable, and the range of 20 to 70 mol% is more preferable.

式（ａ４−８）中、
Ｗ^２は、炭素数３〜３６の環式脂肪族炭化水素を表す。
Ａ^４は、単結合又は置換基を有していてもよい炭素数１〜１７の脂肪族炭化水素基を表す。該脂肪族炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよいが、Ａ^３のうち、酸素原子に結合している原子は炭素原子である。
Ｒ¹⁴は、水素原子、ハロゲン原子、炭素数１〜６のアルキル基又は炭素数１〜６のハロアルキル基を表す。
Ｒ¹⁵及びＲ¹⁶は、それぞれ独立に、炭素数１〜６のアルキル基又は炭素数１〜６のハロアルキル基を表す。 The acid stable monomer (a4) may be a monomer represented by the following formula (a4-8) (hereinafter sometimes referred to as “acid stable monomer (a4-8)”).

In formula (a4-8),
W ² represents a cyclic aliphatic hydrocarbon having 3 to 36 carbon atoms.
A ⁴ represents a single bond or a substituted carbon atoms which may 1 to 17 aliphatic hydrocarbon group. The methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group, but among A ³ , the atom bonded to the oxygen atom is a carbon atom.
R ¹⁴ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms.
R ¹⁵ and R ¹⁶ each independently represents an alkyl group having 1 to 6 carbon atoms or a haloalkyl group having 1 to 6 carbon atoms.

で示される部分構造は、式（ＫＡ−１）〜式（ＫＡ−２２）の脂環式炭化水素を構成する水素原子の１個がＡ^４との結合手に、脂環式炭化水素の環原子に含まれる炭素原子の１つに結合している２つの水素原子が、−Ｏ−ＣＯ−Ｒ¹⁵又は−Ｏ−ＣＯ−Ｒ¹⁶との結合手に置き換わったものを挙げることができる。
Ｗ^２としては、シクロヘキサン環、アダマンタン環、ノルボルナン環及びノルボルネン環が特に好ましい。 In formula (a4-8), W ² preferably has 5 to 18 carbon atoms, and more preferably 6 to 12 carbon atoms. Specifically, the aliphatic ring shown in the form of the alicyclic hydrocarbon shown by the formula (KA-1)-the formula (KA-19) mentioned above can be mentioned. That is, in formula (a4-8)

In the partial structure represented by formula (KA-1) to (KA-22), one of the hydrogen atoms constituting the alicyclic hydrocarbon in the formula (KA-1) to (A-22) has a bond with A ⁴ to form an alicyclic hydrocarbon ring. two hydrogen atoms bonded to one of carbon atoms contained in the atoms, there may be mentioned those replaced by bond to -O-CO-R ¹⁵ or -O-CO-R ^16.
As W ² , a cyclohexane ring, an adamantane ring, a norbornane ring and a norbornene ring are particularly preferable.

式中、
Ｘ^Ｘ１及びＸ^Ｘ２は、それぞれ独立に、単結合又は置換基を有していてもよい炭素数１〜６のアルカンジイル基を表し、Ｘ^Ｘ１及びＸ^Ｘ２がともに単結合であることはなく、式（Ｘ^ｘ−Ａ）、式（Ｘ^ｘ−Ｂ）及び式（Ｘ^ｘ−Ｃ）で表される基の総炭素数は１７以下である。 As the substituent in the aliphatic hydrocarbon group for A ⁴ , a halogen atom, an alkoxy group, an alkylthio group, an acyl group, an aryl group, an aralkyl group, and an aryloxy group are preferable.
The A ^4, for example, it has suitable aliphatic hydrocarbon group formed by combining alkanediyl group and an alicyclic hydrocarbon group. Examples of such an aliphatic hydrocarbon group include groups represented by the following formula (X ^x -A), formula (X ^x -B), and formula (X ^x -C).

Where
X ^X1 and X ^X2 each independently represent a single bond or an alkanediyl group having 1 to 6 carbon atoms which may have a substituent, and X ^X1 and X ^X2 are not single bonds, The total number of carbon atoms of the groups represented by formula (X ^x -A), formula (X ^x -B), and formula (X ^x -C) is 17 or less.

As a methylene group contained in the aliphatic hydrocarbon group for A ⁴ is replaced by an oxygen atom or a carbonyl group include, for example, those exemplified in group of formula (aa) (a-1) .

Among them, ^{A 4} represents a single bond or _* - represented by (* represents a binding position to -O-, s1 is an integer of _{1~6.) - (CH 2)} s1 -CO-O A group is preferable, and a group represented by a single bond or * —CH ₂ —CO—O— (* represents a bond to —O—) is more preferable.

R ¹⁴ is preferably a hydrogen atom or a methyl group.
As the halogen atom in R ^{14 to} R ¹⁶ , a fluorine atom is particularly preferable.
Of the haloalkyl groups of R ¹⁴ and R ¹⁶ , preferred are a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, and the like, more preferably a trifluoromethyl group, a perfluoroethyl group, and a perfluoropropyl group. It is.

Examples of the acid stable monomer (a4-8) are shown below. R ^{14 to} R ¹⁶ and A ⁴ are as defined above.

Among these, the following are preferable.

ここに示した酸安定モノマー（ａ４−８）の具体例において、酸安定モノマー（ａ４−４）の具体例と同様に、部分構造（Ｍｃ’）を部分構造（Ａｃ’）に置き換えたものも、酸安定モノマー（ａ４−８）の具体例として挙げられる。 As the acid stable monomer (a4-8), the following are preferable.

In the specific example of the acid stable monomer (a4-8) shown here, as in the specific example of the acid stable monomer (a4-4), the partial structure (Mc ′) is replaced with the partial structure (Ac ′). Specific examples of the acid-stable monomer (a4-8) are mentioned.

［式（ａ４−８−ａ）及び式（ａ４−８−ｂ）中、
Ｗ^２、Ａ^４、Ｒ^１４、Ｒ^１５及びＲ^１６は、前記と同義である。］ The acid stable monomer (a4-8) can be produced, for example, by reacting a compound represented by the formula (a4-8-a) with a compound represented by the formula (a4-8-b). it can.
Examples of the compound represented by the formula (a4-8-a) include 1-methacryloyloxy-4-oxoadamantane described in JP-A-2002-226436.
Examples of the compound represented by the formula (a4-8-b) include pentafluoropropionic anhydride, heptafluorobutyric anhydride, and trifluoroacetic anhydride. This reaction is preferably carried out by heating near the boiling point of the compound represented by the formula (a4-8-b) to be used.

[In formula (a4-8-a) and formula (a4-8-b),
W ² , A ⁴ , R ¹⁴ , R ¹⁵ and R ¹⁶ are as defined above. ]

When the resin (A) has a structural unit derived from the acid-stable monomer (a4-8), the content is 5 to 90 mol% with respect to the total structural unit (100 mol%) of the resin (AA). The range is preferably 10 to 80 mol%, more preferably 20 to 70 mol%.
When the resin (X) has a structural unit derived from the acid-stable monomer (a4-8), the content is 90 mol% or less with respect to the total structural unit (100 mol%) of the resin (X). The range is preferable, the range of 10 to 80 mol% is more preferable, and the range of 20 to 70 mol% is more preferable.

  When the resin (X) has a structural unit derived from the acid stable monomer (a4), it is represented by the acid stable monomer (a4-6) having a group represented by the formula (3) and / or the formula (4). The structural unit derived from the acid-stable monomer (a4-7) having a group is preferable, and the structural unit derived from the acid-stable monomer (a4-6) is more preferable.

<Manufacture of resin>
The resin (X) is obtained by copolymerizing the compound (aa ′), the compound (ab ′), and a monomer that derives another structural unit as necessary, and the compound (aa ′) and the compound (ab And a compound obtained by copolymerizing a compound (aa ′), a compound (ab ′), and an acid-stable monomer (a4). The compound (aa ′) and the compound (ab ′) More preferably, a compound obtained by polymerizing a compound (a ′ ′), a compound (ab ′), an acid stable monomer (a4-6) and / or an acid stable monomer (a4-7).
The structural unit (aa) and the structural unit (ab) can be regarded as acid stable structural units.

Resin (A) is a monomer derived from structural unit (a1) [preferably a monomer derived from structural unit (a1-1) or structural unit (a1-2)], more preferably an acid stable structural unit. More preferably, a monomer that derives the structural unit (a1-1) and / or the structural unit (a1-2), an acid stable structural unit (a2), and / or an acid stable structure. This is a copolymer of a monomer for deriving the unit (a3).
The resin (A) preferably has at least one of the structural unit (a1-1) having an adamantyl group and the structural unit (a1-2) having a cyclohexyl group as the structural unit (a1). It is more preferable to have a structural unit (a1-1) having an adamantyl group. As the acid stable structural unit (a2), it is preferable to use a structural unit (a2-1) having a hydroxyadamantyl group. The acid stable structural unit (a3) includes at least an acid stable structural unit (a3-1) having a γ-butyrolactone ring and an acid stable structural unit (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring. It is preferable to have one.

  Resin (X) and resin (A) can be produced by subjecting the above-described monomers to a known polymerization method (for example, radical polymerization method).

The weight average molecular weight of the resin (X) is preferably from 8,000 to 80,000, more preferably from 10,000 to 60,000, still more preferably from 10,000 to 40,000, and more preferably from 10,000 to 20 1,000 or less is particularly preferable.
The weight average molecular weight of the resin (A) is preferably from 2,500 to 50,000, more preferably from 3,000 to 30,000, and even more preferably from 3,500 to 10,000.
In addition, the weight average molecular weight here is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis. Detailed analysis conditions for this analysis are described in the Examples of the present application.

<Resist composition>
By including the resin (X), the present resist composition exhibits an effect that an excellent CD uniformity resist pattern can be produced. When the resin (X) itself is insoluble or hardly soluble in an alkaline aqueous solution and does not have the property of being soluble in an alkaline aqueous solution by the action of an acid, as described above, the resin (A) is a resist composition. Contained in In addition to these resins, the resist composition contains an acid generator (B) and a solvent (D), and if necessary, an additive such as a basic compound called a quencher in the art. You may do it. In addition, what remove | excluded the solvent (D) from the resist composition is called "solid content" of a resist composition. The content ratio of the solid content with respect to the total resist composition mass can be measured by a known analysis means such as liquid chromatography and gas chromatography.

<Acid generator (B)>
The acid generator is classified into a nonionic type and an ionic type. The acid generator (B) contained in the resist composition may be a nonionic acid generator, an ionic acid generator, or a combination thereof. Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, DNQ 4- Sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. The ionic acid generator is typically an onium salt containing an onium cation (for example, a diazonium salt, a phosphonium salt, a sulfonium salt, or an 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 include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, and JP-A 63-163452. No. 62-153853, Japanese Patent Laid-Open No. 63-146029, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. Compounds that generate acids by the described radiation can be used.

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、置換基を有していてもよい炭素数１〜１７の２価の脂肪族炭化水素基を表す。該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
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を表し、該脂肪族炭化水素基を構成するメチレン基は、酸素原子、カルボニル基又はスルホニル基に置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。 The acid generator is preferably an acid generator represented by the following formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”).

In formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a C 1-17 divalent aliphatic hydrocarbon group which may have a substituent. The methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y represents an optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group is replaced by an oxygen atom, a carbonyl group or a sulfonyl group. May be.
Z ⁺ represents an organic cation.

Examples of the perfluoroalkyl group include those similar to the fluorinated alkyl group.
In the formula (B1), Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom, and both Q ¹ and Q ² are more preferably a fluorine atom.

式（ｂ１−１）〜式（ｂ１−６）中、
Ｌ^b2は、単結合又は炭素数１〜１５の２価の脂肪族炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２の２価の脂肪族炭化水素基を表す。
Ｌ^b4は、炭素数１〜１３の２価の脂肪族炭化水素基を表し、Ｌ^b3及びＬ^b4の合計炭素数の上限は１３である。
Ｌ^b5は、炭素数１〜１５の２価の脂肪族炭化水素基を表す。
Ｌ^b6及びＬ^b7は、それぞれ独立に、炭素数１〜１５の２価の脂肪族炭化水素基を表し、Ｌ^b6及びＬ^b7の合計炭素数の上限は１６である。
Ｌ^b8は、炭素数１〜１４の２価の脂肪族炭化水素基を表す。
Ｌ^b9及びＬ^b10は、それぞれ独立に、炭素数１〜１１の２価の脂肪族炭化水素基を表し、Ｌ^b9及びＬ^b10の合計炭素数の上限は１２である。 Methylene group constituting the aliphatic hydrocarbon group for L ^b1 is, those which replaced by an oxygen atom or a carbonyl group, for example, represented by any one of the following formulas (b1-1) ~ formula (b1-6) Groups. Incidentally, the formula (b1-1) ~ formula (b1-6) has its left and right are described in accordance with the formula (B1), the left bond ^{is, C (Q 1) (Q} 2) coupled with and The right hand is connected to Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6). * Represents a bond, one bonded to Y and the other bonded to a carbon atom of CQ ¹ Q ² .

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

As for bivalent group represented by a formula (b1-1), the following are mentioned, for example.

As for bivalent group represented by a formula (b1-2), the following are mentioned, for example.

As for bivalent group represented by a formula (b1-3), the following are mentioned, for example.

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.

L ^b1 is preferably a group represented by any one of formulas (b1-1) to (b1-4), and more preferably any one of formulas (b1-1) to (b1-3). It is a group represented.
Among these, as L ^b1 , a divalent group represented by the formula (b1-1) and a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond or a methylene group are more preferable. .

Examples of the substituent of the aliphatic hydrocarbon group in L ^b1 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, and 2 to 2 carbon atoms. 4 acyl groups, glycidyloxy groups and the like.

Y is preferably an alkyl group and an alicyclic hydrocarbon group, more preferably an alkyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and an alicyclic hydrocarbon having 3 to 12 carbon atoms. The group is particularly preferred.
Examples of the substituent of the aliphatic hydrocarbon group in Y include, for example, a halogen atom (excluding a fluorine atom), a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, A aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group or a group represented by — (CH ₂ ) _j2 —O—CO—R ^b1 (wherein R ^b1 is the number of carbon atoms) Represents a hydrocarbon group of 1 to 16. j2 represents an integer of 0 to 4). Here, the aromatic hydrocarbon group and the aralkyl group may further have, for example, an alkyl group, a halogen atom or a hydroxy group. Of these, a hydroxy group is preferable.
Examples of the group in which the methylene group constituting the aliphatic hydrocarbon group of Y is replaced by an oxygen atom, a sulfonyl group or a carbonyl group include a cyclic ether group (one or two of the methylene groups constituting the alicyclic hydrocarbon group). One is replaced by an oxygen atom), a cyclic ketone group (a group in which one or two of the methylene groups constituting the alicyclic hydrocarbon group are replaced by a carbonyl group), a sultone ring group (which forms an alicyclic hydrocarbon group) Of two methylene groups adjacent to each other are groups in which oxygen atoms and sulfonyl groups are replaced, respectively, and lactone ring groups (methylene groups constituting alicyclic hydrocarbon groups are adjacent to each other). , Groups in which oxygen atoms and carbonyl groups are substituted, respectively).

A preferred group of the alicyclic hydrocarbon group of Y is an alicyclic hydrocarbon group represented by any of the following formulas (Y1) to (Y5), and among these, the formula (Y1), The alicyclic hydrocarbon group represented by any one of the formula (Y2), the formula (Y3) and the formula (Y5) is more preferable, and the alicyclic represented by any one of the formula (Y1) and the formula (Y2). A hydrocarbon group is particularly preferred.

Examples of the alicyclic hydrocarbon group having a substituent include the following.

When Y is an alkyl group and L ^b1 is a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms, the methylene group of the divalent aliphatic hydrocarbon group bonded to Y is oxygen It is preferably replaced by an atom or a carbonyl group. In this case, the methylene group constituting the alkyl group of Y is not replaced with an oxygen atom or a carbonyl group.

  The alicyclic hydrocarbon group of Y is preferably a group having an adamantane ring as shown in the formulas (Y1) and (Y2), and when these have a substituent, the substituent is preferably a hydroxy group . That is, as the alicyclic hydrocarbon group having a substituent, a hydroxyadamantyl group is particularly preferable as Y.

Examples of the sulfonate anion include those represented by any one of formulas (b1-1-1) to (b1-1-9). In these sulfonate anions, L ^b1 is preferably a group represented by the formula (b1-1). R ^b2 and R ^b3 are each independently defined as a substituent that may optionally be present in the aliphatic hydrocarbon group of Y, preferably an aliphatic hydrocarbon group having 1 to 4 carbon atoms, A methyl group is more preferred.

  Specific examples of the sulfonate anion represented by any one of the formulas (b1-1-1) to (b1-1-9) include, for example, a sulfonate anion described in JP2010-204646A. Can be mentioned.

Examples of the sulfonate anion include the following.

Examples of the sulfonate anion in which Y is the lactone ring group or the sultone ring group include those represented by any of the following formulas (b1-s-36) to (b1-s-41). .

Examples of the organic cation (Z ⁺ ) in the acid generator (B1) include organic onium cations such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, an organic benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an organic cation represented by any of the following formulas (b2-1) to (b2-4) is more preferable.

式（ｂ２−１）〜式（ｂ２−４）において、
Ｒ^b4〜Ｒ^b6は、それぞれ独立に、炭素数１〜３０の炭化水素基を表し、この炭化水素基としては、炭素数１〜３０のアルキル基、炭素数３〜１８の脂環式炭化水素基及び炭素数６〜１８の芳香族炭化水素基が好ましい。該アルキル基は、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を有していてもよく、該脂環式炭化水素基は、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を有していてもよく、該芳香族炭化水素基は、ハロゲン原子、ヒドロキシ基、炭素数１〜１８のアルキル基、炭素数３〜１８の脂環式炭化水素基又は炭素数１〜１２のアルコキシ基を有していてもよい。
Ｒ^b7及びＲ^b8は、それぞれ独立に、ヒドロキシ基、炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表す。
ｍ２及びｎ２は、それぞれ独立に０〜５の整数を表す。
Ｒ^b9及びＲ^b10は、それぞれ独立に、炭素数１〜１８のアルキル基又は炭素数３〜１８の脂環式炭化水素基を表す。
Ｒ^b11は、水素原子、炭素数１〜１８のアルキル基、炭素数３〜１８の脂環式炭化水素基又は炭素数６〜１８の芳香族炭化水素基を表す。
Ｒ^b9〜Ｒ^b11は、それぞれ独立に、脂肪族炭化水素基であり、この脂肪族炭化水素基としては、炭素数は１〜１２のアルキル基であることが好ましく、炭素数は３〜１８の脂環式炭化水素基であることが好ましく、炭素数４〜１２であることがより好ましい。
Ｒ^b12は、炭素数１〜１８の炭化水素基を表す。この炭化水素基のうち、芳香族炭化水素基は、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、炭素数３〜１８の脂環式炭化水素基又は炭素数１〜１２のアルキルカルボニルオキシ基を有していてもよい。
Ｒ^b9とＲ^b10とは、それぞれ独立に、互いに結合して３員環〜１２員環（好ましくは３員環〜７員環）を形成していてもよく、これらの３員環〜１２員環は、脂環式炭化水素又は脂環式炭化水素を構成するメチレン基が、酸素原子、硫黄原子又はカルボニル基に置き換わった環である。
Ｒ^b11とＲ^b12とは、それぞれ独立に、互いに結合して３員環〜１２員環（好ましくは３員環〜７員環）を形成していてもよく、これらの３員環〜１２員環は、脂環式炭化水素又は脂環式炭化水素を構成するメチレン基が、酸素原子、硫黄原子又はカルボニル基に置き換わった環である。

In formula (b2-1) to formula (b2-4),
R ^{b4 to} R ^b6 each independently represents a hydrocarbon group having 1 to 30 carbon atoms, and examples of the hydrocarbon group include an alkyl group having 1 to 30 carbon atoms and an alicyclic hydrocarbon having 3 to 18 carbon atoms. And an aromatic hydrocarbon group having 6 to 18 carbon atoms are preferred. The alkyl group may have 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 alicyclic hydrocarbon group includes a halogen atom and a carbon number. It may have 2 to 4 acyl groups or glycidyloxy groups, and the aromatic hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 18 carbon atoms, or an alicyclic group having 3 to 18 carbon atoms. You may have a hydrocarbon group or a C1-C12 alkoxy group.
R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl 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.
R ^b9 and R ^b10 each independently represent an alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms.
R ^b11 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^{b9 to} R ^b11 are each independently an aliphatic hydrocarbon group, and the aliphatic hydrocarbon group is preferably an alkyl group having 1 to 12 carbon atoms, and having 3 to 18 carbon atoms. It is preferable that it is an alicyclic hydrocarbon group, and it is more preferable that it is C4-C12.
R ^b12 represents a hydrocarbon group having 1 to 18 carbon atoms. Among these hydrocarbon groups, the aromatic hydrocarbon group is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or 1 to 12 carbon atoms. It may have an alkylcarbonyloxy group.
R ^b9 and R ^b10 may be independently bonded to each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring), and these 3- to 12-membered rings The ring is a ring in which an alicyclic hydrocarbon or a methylene group constituting the alicyclic hydrocarbon is replaced with an oxygen atom, a sulfur atom or a carbonyl group.
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), and these 3- to 12-membered rings. The ring is a ring in which an alicyclic hydrocarbon or a methylene group constituting the alicyclic hydrocarbon is replaced with an oxygen atom, a sulfur atom or a carbonyl group.

R ^{b13 to} R ^b18 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b11 represents an oxygen atom or a sulfur atom.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 are the same or different from each other, when p2 is 2 or more, the plurality of R ^b14 are the same or different from each other, and when s2 is 2 or more, a plurality of R ^{b15 Are} the same or different from each other, and when t2 is 2 or more, the plurality of R ^b18 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 ring formed by combining 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. Is mentioned.
Examples of the ring formed by combining R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

式（ｂ２−１−１）中、
Ｒ^b19、Ｒ^b20及びＲ^b21は、それぞれ独立に、ハロゲン原子（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又は炭素数１〜１２のアルコキシ基を表し、該脂肪族炭化水素基は、ハロゲン原子、ヒドロキシ基、炭素数１〜１２のアルコキシ基、炭素数６〜１８の芳香族炭化水素基、炭素数２〜４のアシル基又はグリシジルオキシ基を有していてもよい。
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以上のとき、複数のＲ^b19は互いに同一又は相異なり、ｗ２が２以上のとき、複数のＲ^b20は互いに同一又は相異なり、ｘ２が２以上のとき、複数のＲ^b21は互いに同一又は相異なる。 Specific examples of the organic cation represented by the formulas (b2-1) to (b2-4) include those described in JP2010-204646A.
Among these, a cation (b2-1) is preferable, and an organic cation represented by the following formula (b2-1-1) [hereinafter referred to as “cation (b2-1-1)”. ], More preferably a triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0) or a tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = X2 = 1, and R ^b19 , R ^b20 and R ^b21 are all methyl groups).

In formula (b2-1-1),
R ^b19 , R ^b20 and 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 or an alkoxy group having 1 to 12 carbon atoms, The aliphatic hydrocarbon group has a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. It may be.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1).
When v2 is 2 or more, the plurality of R ^b19 are the same or different from each other. When w2 is 2 or more, the plurality of R ^b20 are the same or different from each other. When x2 is 2 or more, the plurality of R ^b21 are the same. Or different.

Examples of the cation (b2-1-1) include the following compounds.

Examples of the organic cation represented by the formula (b2-3) include the following compounds.

  The acid generator (B1) is a combination of a sulfonate anion and an organic cation. The sulfonate anion and the organic cation can be arbitrarily combined as shown in Table 2, for example. In Table 2, the sulfonate anion represented by the formula (b1-s-1) is represented as “(b1-s-1)” according to the formula number, and the formula (b2-c-1) Is represented as “(b2-c-1)” or the like according to the formula number.

  Further preferred acid generators (B1) are those represented by any one of formulas (B1-1) to (B1-17). Among them, formula (B1-2), formula (B1-3), formula (B1-6), formula (B1-7), formula (B1-11), formula (B1-12), formula (B1-13) And (B1-14) are more preferable. Formula (B1-2), Formula (B1-3), (B1-6), Formula (B1-7), and Formula (B1-11) are more preferable. ) Is more preferable.

  The acid generator (B) may contain an acid generator different from the acid generator (B1). In this case, the content ratio of the acid generator (B1) in the total amount of the acid generator (B) is 70 mass% or more is preferable, and 90 mass% or more is more preferable. However, it is more preferable that the acid generator (B) in the resist composition of the present invention is substantially only the acid generator (B1).

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The resist composition of the present invention may contain a basic compound (C). The “basic compound” as used herein means a compound having a property of capturing an acid, particularly a compound having a property of capturing an acid generated from the acid generator described above.
The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by the formula (C1) to a compound represented by the formula (C8), more preferably a compound represented by the formula (C1-1). It is done.

［式（Ｃ１）及び式（Ｃ１−１）中、
Ｒ^c1〜Ｒ^c3は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基、炭素数５〜１０の脂環式炭化水素基又は炭素数６〜１０の芳香族炭化水素基を表し、該アルキル基及び該脂環式炭化水素基に含まれる水素原子は、ヒドロキシ基、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、該芳香族炭化水素基に含まれる水素原子は、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５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。
Ｒ^c4は、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５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基を表す。
ｍ３は０〜３の整数を表し、ｍ３が２以上のとき、複数のＲ^c4は、それぞれ独立である。］

[In Formula (C1) and Formula (C1-1),
R ^{c1 to} R ^c3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms, The hydrogen atom contained in the alkyl group and the alicyclic hydrocarbon group may be substituted with a hydroxy group, an amino group or an alkoxy group having 1 to 6 carbon atoms, and hydrogen contained in the aromatic hydrocarbon group The atom may be substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms. Good.
R ^c4 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
m3 represents an integer of 0 to 3, and when m3 is 2 or more, the plurality of R ^c4 are independent of each other. ]

［式（Ｃ２）〜式（Ｃ４）中、
Ｒ^c5、Ｒ^c6、Ｒ^c7及びＲ^c8は、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c9は、炭素数１〜６のアルキル基、炭素数３〜６の脂環式炭化水素基又は炭素数２〜６のアルカノイル基を表す。
ｎ３は０〜８の整数を表し、ｎ３が２以上のとき、複数のＲ^c9は、それぞれ独立である。］
アルカノイル基としては、アセチル基、２−メチルアセチル基、２，２−ジメチルアセチル基、プロピオニル基、ブチリル基、イソブチリル基、ペンタノイル基、２，２−ジメチルプロピオニル基等が挙げられる。

[In the formulas (C2) to (C4),
R ^c5 , R ^c6 , R ^c7 and R ^c8 each independently represent the same meaning as R ^c1 .
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an alkanoyl group having 2 to 6 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 are independent of each other. ]
Examples of the alkanoyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, and 2,2-dimethylpropionyl group.

［式（Ｃ５）及び式（Ｃ６）中、
Ｒ^c10、Ｒ^c11、Ｒ^c12、Ｒ^c13及びＲ^c16は、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c14、Ｒ^c15及びＲ^c17は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
ｏ３及びｐ３は、それぞれ独立に０〜３の整数を表し、ｏ３が２以上であるとき、複数のＲ^c14は同一又は相異なり、ｐ３が２以上であるとき、複数のＲ^c15は同一又は相異なる。
Ｌ^c1は、炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

[In Formula (C5) and Formula (C6),
R ^c10 , R ^c11 , R ^c12 , R ^c13 and R ^c16 each independently represent the same meaning as R ^c1 .
R ^c14 , R ^c15 and R ^c17 each independently represent the same meaning as R ^c4 .
o3 and p3 each independently represent an integer of 0 to 3, when o3 is 2 or more, the plurality of R ^c14 are the same or different, and when p3 is 2 or more, the plurality of R ^c15 are the same or different. Different.
L ^c1 represents an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

［式（Ｃ７）及び式（Ｃ８）中、
Ｒ^c18、Ｒ^c19及びＲ^c20は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
ｑ３、ｒ３及びｓ３は、それぞれ独立に０〜３の整数を表し、ｑ３が２以上であるとき、複数のＲ^c18は同一又は相異なり、ｒ３が２以上であるとき、複数のＲ^c19は同一又は相異なり、ｓ３が２以上であるとき、複数のＲ^c20は同一又は相異なる。
Ｌ^c2は、単結合又は炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

[In Formula (C7) and Formula (C8),
R ^c18, R ^c19 and R ^c20 in each occurrence independently represent the same meaning as R ^c4.
q3, r3 and s3 each independently represent an integer of 0 to 3, and when q3 is 2 or more, the plurality of R ^c18 are the same or different, and when r3 is 2 or more, the plurality of R ^c19 are the same. Alternatively, when s3 is 2 or more, the plurality of R ^c20 are the same or different.
L ^c2 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

Examples of the compound represented by the formula (C1) include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N- Dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tri Pentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonyl Amine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2- Diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and the like.
Among these, diisopropylaniline is preferable, and 2,6-diisopropylaniline is particularly preferable.

Examples of the compound represented by the formula (C2) include piperazine.
Examples of the compound represented by the formula (C3) include morpholine.
Examples of the compound represented by the formula (C4) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound represented by the formula (C5) include 2,2′-methylenebisaniline.
Examples of the compound represented by the formula (C6) include imidazole and 4-methylimidazole.
Examples of the compound represented by the formula (C7) include pyridine and 4-methylpyridine.
Examples of the compound represented by the formula (C8) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1, 2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipiconylamine, bipyridine and the like.

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

<Solvent (D)>
The resist composition preferably contains a solvent (D). The solvent (D) depends on the type and amount of the resin (X) to be used and the type and amount of the acid generator. In the production of a resist pattern, which will be described later, the resist composition is applied on the substrate. From the viewpoint of good coating properties, an optimum one can be selected as appropriate.

  Examples of the solvent (D) 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 pyruvic acid Examples thereof include esters such as ethyl; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; and cyclic esters such as γ-butyrolactone. Only 1 type may be used for a solvent (D) and it may use 2 or more types together.

<Other ingredients>
The resist composition may contain an additive widely used in the present technical field (hereinafter sometimes referred to as “component (F)”) as necessary. Examples of the component (F) include a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, and a dye.

<Preparation of resist composition>
The resist composition comprises a resin (particularly a combination of resin (A) and resin (X)), an acid generator, and a basic compound (C), a solvent (D) and a component (F) used as necessary. Can be prepared by mixing.
The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select the suitable temperature range from the range of 10-40 degreeC according to the solubility with respect to solvent (D), such as a kind, such as resin (X), and resin (X).
An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature.
The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.01 to 0.2 μm.

  The content ratio of the solvent (D) is, for example, preferably 90% by mass or more, more preferably 92% by mass or more, still more preferably 94% by mass or more, with respect to the total mass of the resist composition. Is 99 mass% or less, More preferably, it is 99.9 mass% or less. The resist composition containing the solvent (D) in such a content ratio can form a composition layer having a thickness of about 30 to 300 nm in, for example, a resist pattern manufacturing method described later.

  The total content of the resin [resin (A) and resin (X)] is preferably, for example, from 80% by mass to 99% by mass with respect to the total mass of the solid content of the resist composition.

  The content of the acid generator is preferably 1 part by mass or more, more preferably 3 parts by mass or more, preferably 30 parts by mass or less, more preferably 25 parts by mass with respect to 100 parts by mass of the resin. It is as follows.

  When using a basic compound (C), it is preferable that the content rate of the basic compound (C) with respect to the total mass of solid content of this resist composition is about 0.01-1 mass%, for example.

  When component (F) is used in the present resist composition, an appropriate content ratio can be adjusted according to the type of component (F).

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) a step of applying the resist composition 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,
(4) A step of heating the composition layer after exposure and (5) a step of developing the composition layer after heating.

  Application of the resist composition on the substrate in the step (1) can be performed by a coating apparatus widely used for applying a resist material for semiconductor microfabrication, such as a spin coater. In this way, a coating film made of a resist composition is formed on the substrate. The film thickness of the coating film can be adjusted by variously adjusting the conditions of the coating apparatus, and the coating conditions can be selected so that the coating film has a desired film thickness by performing an appropriate preliminary experiment or the like. . Various substrates to be subjected to microfabrication can be selected as the substrate before applying the resist composition. The substrate may be washed or an antireflection film may be formed before applying the resist composition. This antireflection film can be formed using, for example, a commercially available composition for organic antireflection films.

In the step (2), the drying is performed by, for example, a heating means using a heating device such as a hot plate (so-called pre-baking), a decompression means using a decompression device, or a combination of these means. The drying conditions are adjusted according to the type of solvent contained in the resist composition. For example, in a heating means using a hot plate, the surface temperature of the hot plate is preferably about 50 to 200 ° C. . Further, in the decompression means, it is suitable to set the internal pressure of the decompressor to about 1 to 1.0 × 10 ⁵ Pa after sealing the substrate on which the coating film is formed in an appropriate decompressor.
Thus, the composition layer is formed on the substrate by removing the solvent from the coating film.

Step (3) is a step of exposing the composition layer, and preferably the composition layer is exposed using an exposure machine. As an exposure light source of the exposure machine, an ultraviolet light source such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ excimer laser (wavelength 157 nm), or a solid-state laser light source (YAG Various types, such as those that convert wavelength of laser light from semiconductor lasers etc. to emit harmonic laser light in the far ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams or extreme ultraviolet light (EUV), etc. Can be used. Further, the exposure machine may be an immersion exposure machine.
The exposure is usually performed through a mask corresponding to a desired pattern to be finely processed. By exposing through a mask, an exposed part (exposed part) and an unexposed part (unexposed part) are generated in the composition layer. In the composition layer of the exposed portion, the acid generator contained in the composition layer receives exposure energy to generate an acid, and further, by the action of the generated acid, the resin (A) [or having an acid labile group Resin (X)] generates a hydrophilic group by the deprotection reaction of the acid labile group, and as a result, the resin (A) in the composition layer of the exposed area [or the resin having an acid labile group ( X)] becomes soluble in an aqueous alkali solution. On the other hand, since the exposure energy is not received in the unexposed area, the resin (A) [or the resin (X) having an acid labile group] remains insoluble or hardly soluble in the alkaline aqueous solution. The solubility of the composition layer in the exposed area and the composition layer in the unexposed area are significantly different from each other in the aqueous alkali solution.

  In step (4), heat treatment (so-called post-exposure baking) is performed to further promote the progress of the deprotection reaction that may occur in the exposed portion. The heat treatment is preferably a heating means using a hot plate shown in step (2). In the hot plate heating in step (4), the surface temperature of the hot plate is preferably about 50 to 200 ° C, more preferably about 70 to 150 ° C.

Step (5) is a step of developing the heated composition layer, and preferably the heated composition layer is developed with a developing device. The term “development” as used herein means that the exposed composition layer is dissolved in the alkaline aqueous solution by bringing the heated composition layer into contact with the alkaline aqueous solution, and the unexposed portion of the composition layer is left on the substrate. To do. Thereby, a resist pattern is manufactured on the substrate.
As the alkaline aqueous solution, those used in this technical field called “alkaline developer” can be used. Examples of the alkaline aqueous solution include an aqueous solution of tetramethylammonium hydroxide and an aqueous solution of (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline).

  The resist pattern formed on the substrate is preferably rinsed with ultrapure water or the like to further remove moisture remaining on the substrate and the resist pattern.

  According to the resist pattern manufacturing method including the steps (1) to (5) as described above, the resist composition can manufacture a resist pattern having excellent CD uniformity (CDU).

<Application>
The resist composition includes a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, and further for immersion exposure. It is suitable as a resist composition.

The present invention will be described more specifically with reference to examples. Hereinafter, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The weight average molecular weight of the resin is a value determined by gel permeation chromatography.
The analysis conditions of gel permeation chromatography are as follows.
Column: TSKgel Multipore HXL-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)

式（Ｆ−１）で表される化合物１３．００部、メチルイソブチルケトン６５．００部及びピリジン８．６９部を仕込み、２３℃で３０分間攪拌し、０℃まで冷却した。同温度を保持したまま、得られた混合物に、式（Ｆ−２）で表される化合物２４．５５部を、１時間かけて添加した。その後、温度を上げ、１０℃に到達した時点で、同温度で１時間攪拌した。得られた反応物にｎ−ヘプタン３３３．７３部、５％塩酸水溶液３２．０９部及びイオン交換水１００．１２部を加え、２３℃で３０分間攪拌した。回収された有機層に、イオン交換水１００．１２部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を４回行った。回収された有機層を濃縮し式（Ｍ−Ｆ）で表される化合物３０．３１部を得た。
ＭＳ：３５２．１ Synthesis Example 1 Synthesis of Compound Represented by Formula (MF)]

First, 13.00 parts of the compound represented by the formula (F-1), 65.00 parts of methyl isobutyl ketone, and 8.69 parts of pyridine were charged, stirred at 23 ° C. for 30 minutes, and cooled to 0 ° C. While maintaining the same temperature, 24.55 parts of the compound represented by the formula (F-2) was added to the obtained mixture over 1 hour. Thereafter, the temperature was raised, and when the temperature reached 10 ° C., the mixture was stirred at the same temperature for 1 hour. To the obtained reaction product, 33.73 parts of n-heptane, 32.09 parts of 5% hydrochloric acid aqueous solution and 100.12 parts of ion-exchanged water were added, followed by stirring at 23 ° C. for 30 minutes. To the recovered organic layer, 100.12 parts of ion-exchanged water was charged, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed 4 times. The collected organic layer was concentrated to obtain 30.31 parts of a compound represented by the formula (MF).
MS: 352.1

式（Ｋ−１）で表される化合物１３．００部、メチルイソブチルケトン６５．００部及びピリジン８．６９部を仕込み、２３℃で３０分間攪拌し、０℃まで冷却した。同温度を保持したまま、得られた混合物に、式（Ｋ−２）で表される化合物１６．１９部を、１時間かけて添加した。その後、温度を上げ、１０℃に到達した時点で、同温度で１時間攪拌した。得られた反応物にｎ−ヘプタン３０８．６４部、５％塩酸水溶液３２．０９部及びイオン交換水９２．５９部を加え、２３℃で３０分間攪拌した。回収された有機層に、イオン交換水９２．５９部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を４回行った。回収された有機層を濃縮し、式（Ｍ−Ｋ）で表される化合物１９．４９部を得た。
ＭＳ：２６４．１ Synthesis Example 2 [Synthesis of Compound Represented by Formula (M-K)]

First, 13.00 parts of the compound represented by the formula (K-1), 65.00 parts of methyl isobutyl ketone, and 8.69 parts of pyridine were charged, stirred at 23 ° C. for 30 minutes, and cooled to 0 ° C. While maintaining the same temperature, 16.19 parts of the compound represented by the formula (K-2) was added to the obtained mixture over 1 hour. Thereafter, the temperature was raised, and when the temperature reached 10 ° C., the mixture was stirred at the same temperature for 1 hour. To the obtained reaction product, 308.64 parts of n-heptane, 32.09 parts of 5% hydrochloric acid aqueous solution and 92.59 parts of ion-exchanged water were added, followed by stirring at 23 ° C. for 30 minutes. The recovered organic layer was charged with 92.59 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed 4 times. The recovered organic layer was concentrated to obtain 19.49 parts of a compound represented by the formula (M-K).
MS: 264.1

Resins were synthesized using monomers (MA) to monomers (M-K) shown below.

Synthesis Example 3 [Synthesis of Resin A1]
Monomer (ME) and monomer (MF) are used as monomers and mixed so that the molar ratio (monomer (ME): monomer (MF)) is 70:30. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 72 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A1 (copolymer) having a weight average molecular weight of 1.5 × 10 ^{4 in} a yield of 78%. It was. This resin A1 has the following structural units.

Synthesis Example 4 [Synthesis of Resin A2]
Monomer (ME) and monomer (MF) are used as monomers and mixed so that the molar ratio (monomer (ME): monomer (MF)) is 80:20. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 72 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A2 (copolymer) having a weight average molecular weight of 1.5 × 10 ^{4 in} a yield of 77%. It was. This resin A2 has the following structural units.

Synthesis Example 5 [Synthesis of Resin A3]
Monomer (ME) and monomer (MF) are used as monomers and mixed so that the molar ratio (monomer (ME): monomer (MF)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 72 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A3 (copolymer) having a weight average molecular weight of 1.6 × 10 ^{4 in} a yield of 73%. It was. This resin A3 has the following structural units.

Synthesis Example 6 [Synthesis of Resin A4]
As a monomer, a monomer (ME), a monomer (MF), and a monomer (MG) are used, and the molar ratio thereof (monomer (ME): monomer (MF): monomer (MG) ) Was 50:10:40, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 72 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A4 (copolymer) having a weight average molecular weight of 1.4 × 10 ^{4 in} a yield of 86%. It was. This resin A4 has the following structural units.

Synthesis Example 7 [Synthesis of Resin A5]
As the monomer, the monomer (M−H), the monomer (M−I), the monomer (M−D), the monomer (M−J) and the monomer (M−C) are used, and the molar ratio (monomer (M−H)) : Monomer (M-I): monomer (MD): monomer (M-J): monomer (M-C)) are mixed so as to be 32: 7: 8: 10: 43. 1.5 mass times dioxane was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 2 × 10 ³ resin A5 (copolymer) was obtained with a yield of 63%. This resin A5 has the following structural units.

Synthesis Example 8 [Synthesis of Resin A6]
As the monomer, monomer (MB), monomer (MC) and monomer (MD) are used, and the molar ratio (monomer (MB): monomer (MC): monomer (MD) ) Was 35:45:20, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.0 mol% and 3.0 mol%, respectively, based on the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 0 × 10 ³ resin A6 (copolymer) was obtained with a yield of 75%. This resin A6 has the following structural units.

Synthesis Example 9 [Synthesis of Resin A7]
Monomer (MA) and monomer (MB) are used as monomers, and mixed so that the molar ratio (monomer (MB): monomer (MD)) is 80:20. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.5 mol% and 1.5 mol%, respectively, based on the total monomer amount, and these were added at 70 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 8 × 10 ⁴ resin A7 (copolymer) was obtained with a yield of 70%. This resin A7 has the following structural units.

Synthesis Example 10 [Synthesis of Resin A8]
Monomers (ME) and monomers (M-K) are used as the monomers, and mixed so that the molar ratio (monomer (ME): monomer (M-K)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 72 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A8 (copolymer) having a weight average molecular weight of 1.9 × 10 ^{4 in} a yield of 64%. It was. This resin A8 has the following structural units.

Synthesis Example 11: [Synthesis of Resin A9]
As the monomer, monomer (M−H), monomer (M−I), monomer (M−D), monomer (M−C) and monomer (M−J) are used, and the molar ratio (monomer (M−H)) : Monomer (M-I): monomer (MD): monomer (M-C): monomer (M-J)) are mixed at a ratio of 30: 14: 6: 20: 30, In this monomer mixture, 1.5 mass times dioxane was mixed with respect to the total mass of all monomers. Into the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were respectively added to 1.00 mol% and 3.00 mol% with respect to the total number of moles of all monomers. It added so that it might become. This was polymerized by heating at 73 ° C. for about 5 hours. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin was filtered and collected. It is again dissolved in dioxane, poured into a mixed solvent of a large amount of methanol and water to precipitate the resin, and the precipitated resin is filtered and collected twice to perform reprecipitation purification, and the weight average molecular weight is 8 the copolymer is .1 × 10 ³ was obtained in a yield of 65%. This copolymer has the following structural units derived from the monomer (M-H), the monomer (M-I), the monomer (M-D), the monomer (M-C), and the monomer (M-J), respectively. This is referred to as Resin A9.

Examples and Comparative Examples <Preparation of Resist Composition>
The components shown in Table 3 were mixed and dissolved in the following solvent, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

Ｂ２：ＷＯ２００８／９９８６９号の実施例及び特開２０１０−２６４７８号公報の実施例に従って合成

Ｂ３：特開２００５−２２１７２１号公報の実施例に従って合成

<Resin>
A1 to A9: Resin A1 to Resin A9
<Acid generator>
B1: Synthesis according to the example of JP 2010-152341 A

B2: synthesized according to the example of WO2008 / 99869 and the example of JP2010-26478A

B3: synthesized according to the example of JP-A-2005-221721

<Basic compound: Quencher>
C1: 2,6-diisopropylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.)
<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 of resist composition layer>
The resist composition was applied (spin coated) to a 12-inch silicon wafer (substrate) so that the film thickness after drying was 0.15 μm. After coating, the composition was pre-baked (PB) for 60 seconds on the direct hot plate at the temperature shown in the PB column of Table 3 to form a composition layer on the wafer.
The wafer on which the composition layer was formed in this manner was subjected to water rinsing 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 results are shown in Table 4.

<Immersion exposure evaluation of resist composition>
An organic antireflective coating composition (ARC-29; manufactured by Nissan Chemical Co., Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to form an organic reflective film having a thickness of 78 nm on the wafer. A prevention film was formed.
On the organic antireflection film, the above resist composition was applied (spin coated) so that the film thickness after drying (pre-baking) was 85 nm.
After coating, the silicon wafer was pre-baked on a direct hot plate for 60 seconds at the temperature described in the “PB” column of Table 3 to form a composition layer. ArF excimer stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light) on a silicon wafer on which the composition layer is formed, and a contact hole pattern (hole pitch 100 nm) Using a mask for forming a hole diameter of 70 nm), the exposure amount was changed stepwise to perform exposure. Note that ultrapure water was used as the immersion medium.
After the exposure, the silicon wafer was heated (post-exposure baking process) for 60 seconds at a temperature described in the “PEB” column of Table 3 on a hot plate.
This silicon wafer was subjected to paddle development for 60 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution to obtain a resist pattern.

  In the resist pattern obtained after development, the exposure amount at which the hole diameter formed using a mask with a hole pitch of 100 nm / hole diameter of 70 nm was 55 nm was defined as effective sensitivity.

<Evaluation of CD uniformity (CDU)>
In terms of effective sensitivity, the hole diameter of a pattern formed with a mask having a hole diameter of 70 nm was measured 24 times per hole, and the average value was taken as the average hole diameter of one hole. A standard deviation was obtained using a population obtained by measuring 400 average hole diameters of a pattern formed with a mask having a hole diameter of 70 nm in the same wafer. The results are shown in Table 4.

The resist patterns obtained using the resist compositions of Examples 1 to 11 were able to form resist patterns with excellent CD uniformity. In addition, the number of defects was small.
On the other hand, in the resist composition of Comparative Example 1, the CD uniformity of the resulting resist pattern was poor.

  According to the resist composition of the present invention, a resist pattern having excellent CD uniformity (CDU) can be produced.

Claims (11)

A resin (X) having a structural unit represented by formula (aa) and a structural unit represented by formula (ab);
A resist composition containing an acid generator (B).

[In the formula (aa)
A ^aa1 represents a C1-C6 alkanediyl group which may have a substituent or a group represented by the formula (a-1).

(In the formula (a-1),
s represents an integer of 0 or 1.
A ¹⁰ , A ¹¹ and A ¹² each independently represent a C 1-5 divalent aliphatic hydrocarbon group which may have a substituent.
X ¹⁰ and X ¹¹ each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group. )
R ^aa1 represents a hydrogen atom or a methyl group.
R ^aa2 represents an ^optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. Good. ]

[In the formula (ab),
A ^ab1 represents a single bond, an alkanediyl group having 1 to 6 carbon atoms which may have a substituent, or a group represented by the formula (a-2).

(In the formula (a-2),
t represents an integer of 0 or 1.
A ³⁰ , A ³¹ and A ³² each independently represent a C 1-5 divalent aliphatic hydrocarbon group which may have a substituent.
X ³⁰ and X ³¹ each independently represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
* Is a bond with —O—C (O) —O—CH ₂ —R ^ab2 . )
R ^ab1 represents a hydrogen atom or a methyl group.
R ^ab2 represents an aromatic hydrocarbon group having 6 to 18 carbon atoms. ] The resist composition according to claim 1, wherein A ^{aa1 in the} formula (aa) is an alkanediyl group having 1 to 6 carbon atoms. The resist composition according to claim 1, wherein A ^{aa1 in the} formula (aa) is a methylene group. 4. The resist composition according to claim 1, wherein A ^{ab1 in the} formula (ab) is an alkanediyl group having 1 to 6 carbon atoms. The resist composition according to claim 1, wherein A ^{ab1 in the} formula (ab) is an ethylene group. The resist composition according to claim 1, wherein R ^ab2 in the formula (ab) is a group represented by the formula (ab-1) or a group represented by the formula (ab-2).

The resist composition according to claim 1, wherein the (B) is an acid generator 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 divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y represents an optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group is replaced with an oxygen atom, a sulfonyl group or a carbonyl group. May be.
Z ⁺ represents an organic cation. ]   8. The resist composition according to claim 7, wherein Y in the formula (B1) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent.   The resist composition according to any one of claims 1 to 8, further comprising a resin (A) that is insoluble or hardly soluble in an alkaline aqueous solution and becomes soluble in an alkaline aqueous solution by the action of an acid.   Furthermore, the resist composition in any one of Claims 1-9 containing a solvent. (1) The process of apply | coating the resist composition in any one of Claims 1-10 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating,
A method for producing a resist pattern including: