JP2012185488A - Resist composition and method for producing resist pattern - Google Patents

Abstract

［式中、Ｒ^aa1は、水素原子又はメチル基；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；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。］
【選択図】なしA resist composition capable of obtaining a resist pattern having excellent line edge roughness (LER) is provided.
A resist composition containing a resin having a structural unit represented by formula (aa), an acid generator, and a cyclic ketone solvent.

[Wherein, R ^aa1 represents a hydrogen atom or a methyl group; R ^aa2 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and constitutes the aliphatic hydrocarbon group. The methylene group may be replaced by an oxygen atom or a carbonyl group; A ^aa1 is an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (a-1) Represents. ]
[Selection figure] None

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. A resist composition is used in such a photolithography technique. As a resin used in such a resist composition, for example, Patent Document 1 discloses a resin composed of a structural unit represented by the formula (u-A) and a structural unit represented by the formula (u-B). A resin comprising a structural unit represented by the formula (u-C), a structural unit represented by the formula (u-D) and a structural unit represented by the formula (u-B), an acid generator, and propylene A resist composition containing a solvent comprising glycol monomethyl ether and propylene glycol monomethyl ether acetate is described.

JP 2010-197413 A

  A resist pattern manufactured from the above-described resist composition known in the art sometimes does not always satisfy the line edge roughness (LER).

［式（ａａ）中、
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。
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）

（式（ａ−１）中、
ｓは０又は１の整数を表す。
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。
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の脂肪族炭化水素基を表す。）
で表される基を表す。］
〔２〕前記（Ｄ１）が、５〜７員環の環状ケトン溶剤である〔１〕記載のレジスト組成物。
〔３〕前記（Ｄ１）が、以下の式（ｄ）で表される溶剤である〔１〕記載のレジスト組成物。

［式（ｄ）中、ｎｄは１〜３の整数を表す。］
〔４〕さらに、グリコールエーテルエステル溶剤、グリコールエーテル溶剤、エステル溶剤、ケトン溶剤及び環状エステル溶剤から選ばれる少なくとも１種の溶剤を含有する〔１〕〜〔３〕のいずれか記載のレジスト組成物。
〔５〕前記式（ａａ）のＲ^aa２が、フッ素原子を有する脂肪族炭化水素基である〔１〕〜〔４〕のいずれか記載のレジスト組成物。
〔６〕前記式（ａａ）のＡ^aa1が、炭素数１〜６のアルカンジイル基である〔１〕〜〔５〕のいずれか記載のレジスト組成物。
〔７〕前記式（ａａ）のＡ^aa1が、メチレン基である〔１〕〜〔５〕のいずれか記載のレジスト組成物。
〔８〕前記（Ａ）が、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である〔１〕〜〔７〕のいずれか記載のレジスト組成物。
〔９〕前記（Ｂ）が、以下の式（Ｂ１）で表される酸発生剤である〔１〕〜〔８〕のいずれか記載のレジスト組成物。

［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。］
〔１０〕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〔９〕記載のレジスト組成物。
〔１１〕（１）〔１〕〜〔１０〕のいずれか記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層を露光する工程、
（４）露光後の組成物層を加熱する工程及び
（５）加熱後の組成物層を現像する工程、
を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] (A) a resin having a structural unit represented by formula (aa),
A resist composition containing (B) an acid generator and (D1) a cyclic ketone solvent.

[In the formula (aa)
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.
A ^aa1 is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a formula (a-1)

(In the formula (a-1),
s represents an integer of 0 or 1.
X ¹⁰ and X ¹¹ each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁰ , A ¹¹ and A ¹² each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. )
Represents a group represented by ]
[2] The resist composition according to [1], wherein (D1) is a 5- to 7-membered cyclic ketone solvent.
[3] The resist composition according to [1], wherein (D1) is a solvent represented by the following formula (d).

[In the formula (d), nd represents an integer of 1 to 3. ]
[4] The resist composition according to any one of [1] to [3], further comprising at least one solvent selected from a glycol ether ester solvent, a glycol ether solvent, an ester solvent, a ketone solvent, and a cyclic ester solvent.
[5] The resist composition according to any one of [1] to [4], wherein R ^{aa2 in the} formula (aa) is an aliphatic hydrocarbon group having a fluorine atom.
[6] The resist composition according to any one of [1] to [5], wherein A ^{aa1 in the} formula (aa) is an alkanediyl group having 1 to 6 carbon atoms.
[7] The resist composition according to any one of [1] to [5], wherein A ^{aa1 in the} formula (aa) is a methylene group.
[8] The resist composition according to any one of [1] to [7], wherein (A) is a resin 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.
[9] The resist composition according to any one of [1] to [8], wherein (B) is an acid generator represented by the following 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. ]
[10] The resist composition according to [9], wherein Y in the formula (B1) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent.
[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, an excellent line edge roughness (LER) resist pattern can be produced.

  In the present specification, unless otherwise specified, in the description of the structural formula of the compound, the following examples of substituents are applied to any structural formula having the same substituent 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.
The aliphatic hydrocarbon group includes both a chain and a cyclic group, and includes a combination of a chain and a cyclic aliphatic hydrocarbon group unless otherwise defined. 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, propane-2,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3 - Group, 2-methylpropane-1,2-diyl, pentane-1,4-diyl group, and 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).
Of the monocyclic and polycyclic aliphatic hydrocarbon groups described above, a particularly saturated group is sometimes referred to as a “saturated alicyclic hydrocarbon group”. Of the above aliphatic hydrocarbon groups, a particularly saturated group is sometimes referred to as a “saturated hydrocarbon group”.

The aliphatic hydrocarbon group may have a substituent. As such a substituent, a halogen atom, a hydroxy group, an alkoxy group, an alkylthio group, an acyl group, an acyloxy group, an aryl group, an aralkyl group, and an aryloxy group may be mentioned unless otherwise limited.
Here, as a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned.
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 alkylthio group include those in which an oxygen atom of an alkoxy group is replaced by a sulfur atom, such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, an octylthio group, a decylthio group, and the like. Examples include dodecylthio group.
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 ( Includes those in which an alkyl group such as C ₈ ), decanoyl group (C ₁₀ ) and dodecanoyl group (C ₁₂ ) and a carbonyl group are bonded, and those in which an aryl group such as benzoyl group (C ₇ ) and a carbonyl group are bonded 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 ).
Aryloxy groups include phenyloxy group (C ₆ ), naphthyloxy group (C ₁₀ ), anthryloxy 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.

  The saturated hydrocarbon group means a saturated group among the above-described aliphatic hydrocarbon groups, that is, a saturated group among the above-described chain and cyclic aliphatic hydrocarbon groups. Further, the saturated hydrocarbon group may have the same substituent as the aliphatic hydrocarbon group.

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”)
(A) a resin having a structural unit represented by the formula (aa) (hereinafter sometimes referred to as “resin (aa)”),
(B) An acid generator (hereinafter referred to as “acid generator (B)” in some cases) and (D1) a cyclic ketone solvent.
The resist composition of the present invention may further contain a resin other than the resin (aa) (hereinafter referred to as “resin (X)”). Moreover, it is preferable to contain a basic compound called a quencher in the art (hereinafter sometimes referred to as “basic compound (C)”) as necessary.

［式（ａａ）中、
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。
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）

（式（ａ−１）中、
ｓは０又は１の整数を表す。
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。
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の脂肪族炭化水素基を表す。）
で表される基を表す。］ <Resin (aa)>
The resin (aa) has a structural unit represented by the formula (aa) (hereinafter sometimes referred to as “structural unit (aa)”).

[In the formula (aa)
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.
A ^aa1 is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a formula (a-1)

(In the formula (a-1),
s represents an integer of 0 or 1.
X ¹⁰ and X ¹¹ each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁰ , A ¹¹ and A ¹² each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. )
Represents a group represented by ]

<Structural unit (aa)>
The hydrogen atom contained in the alkanediyl group in A ^aa1 may be substituted with a substituent (a monovalent group other than a hydrogen atom). Examples of this substituent include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.

などが挙げられる。＊は結合手を表し、どちらの向きで−Ｏ−ＣＯ−Ｒ^aa2と結合していてもよい。 The group represented by the formula (a-1) (hereinafter sometimes referred to as the group (a-1)) is an oxygen atom, a carbonyl group, a carbonyloxy group, an oxycarbonyl group or the like, as in X ¹⁰ and X ^11. Including. 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.
As the group (a-1) having an oxygen atom,

Etc. * ^{Represents a} bond, and may be bonded to —O—CO—R ^aa2 in any direction.

などが挙げられる。 As the group (a-1) having a carbonyl group,

Etc.

などが挙げられる。 As the group (a-1) having a carbonyloxy group,

Etc.

などが挙げられる。 As the group (a-1) having an oxycarbonyl group,

Etc.

In the formula (aa), A ^aa1 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.

In R ^aa2 , a saturated group is preferable as the aliphatic hydrocarbon group, and an alkyl group and an alicyclic hydrocarbon group are more preferable.
Examples of the substituent in R ^aa2 include a halogen atom, an alkoxy group, an acyl group, and an alkoxycarbonyl group, and a fluorine atom is preferable. 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.
R ^aa2 is an aliphatic hydrocarbon group having a fluorine atom, such as a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, or a 1,1,1-trifluoro group. Ethyl 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-octafluorobutyl 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, 1,1,2,2,3,3 , 4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) Ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6, 6-dodecafluorohexyl group, perfluoropentylmethyl group, perfluoro Examples thereof include a pentyl group, a perfluorohexyl group, a 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.
Examples of the alkoxycarbonyl group include groups in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group.

Further, when the methylene group constituting the aliphatic hydrocarbon group of R ^aa2 is replaced with an oxygen atom or a carbonyl group, the number is about 2 at the maximum.

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

In the structural unit (aa) represented by any one of the formulas (aa-1) to (aa-14), the partial structure (M) shown below is replaced with the partial structure (A) shown below. Specific examples of the structural unit (aa) can be given.

（式（ａａ’）中の符号はいずれも、前記と同義である。） The structural unit (aa) is derived from a compound represented by the formula (aa ′) (hereinafter referred to as “compound (aa ′)”).

(All symbols in formula (aa ′) have the same meanings as described above.)

化合物（ａａ’）は、式（ａａｓ−１）で表される化合物と式（ａａｓ−２）で表される化合物とを、溶媒中、触媒の存在下で反応させることにより製造することができる。溶媒としては、ジメチルホルムアミドなどが挙げられる。触媒としては、炭酸カリウム及びヨウ化カリウムなどを用いればよい。
式（ａａｓ−１）で表される化合物としては、市場から容易に入手できるもの（市販品）が好ましい。市販品としては、メタクリル酸などである。 Compound (aa ′) can be produced, for example, by the following method.

Compound (aa ′) can be produced by reacting a compound represented by formula (aas-1) and a compound represented by formula (aas-2) in a solvent in the presence of a catalyst. . Examples of the solvent include dimethylformamide. As the catalyst, potassium carbonate, potassium iodide, or the like may be used.
As the compound represented by the formula (aas-1), a compound that can be easily obtained from the market (commercial product) is preferable. Examples of commercially available products include methacrylic acid.

式（ａａｓ−３）で表される化合物としては、例えば、クロロアセチルクロリドなどが挙げられる。このクロロアセチルクロリドは市場から容易に入手できる。
式（ａａｓ−４）で表される化合物としては、例えば、２，２，３，３，４，４，４−ヘプタフルオロ−１−ブタノールなどが挙げられる。この２，２，３，３，４，４，４−ヘプタフルオロ−１−ブタノールは市場から容易に入手できる。 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 performed in a solvent in the presence of a base catalyst. Examples of the solvent include tetrahydrofuran. As the base catalyst, pyridine or the like is used.

Examples of the compound represented by the formula (aas-3) include chloroacetyl chloride. This chloroacetyl chloride is readily available from the market.
Examples of the compound represented by the formula (aas-4) include 2,2,3,3,4,4,4-heptafluoro-1-butanol. This 2,2,3,3,4,4,4-heptafluoro-1-butanol is readily available from the market.

The resin (aa) may contain one or more structural units other than the structural unit (aa) such as a structural unit derived from the acid labile monomer (a1) or the acid stable monomer (a4) described later. .
The content ratio of the structural unit (aa) in the resin (aa) is more preferably in the range of 5 to 100 mol%, and further preferably in the range of 10 to 100 mol% with respect to all the structural units of the resin (aa). Resin (aa) which has structural unit (aa) with such a content rate can be manufactured by adjusting the use molar amount of compound (aa ') with respect to the total molar amount of all the monomers used at the time of resin (aa) manufacture. In this case, the structural unit (aa) may be contained alone or in combination of two or more.

The resist composition has a characteristic that it is insoluble or hardly soluble in an alkaline aqueous solution and is converted into a resin that is soluble in an alkaline aqueous solution by the action of an acid (hereinafter, sometimes referred to as “acidic characteristic”). including. Here, “becomes soluble in alkaline aqueous solution by the action of acid” means insoluble or hardly soluble in alkaline aqueous solution before contact with acid, but soluble in alkaline aqueous solution after contact with acid Means that.
The resin (aa) may or may not have such acid action characteristics. However, in the present resist composition, the resin (aa) does not have acid action characteristics, and the resin (aa) It is preferable to contain resin (X) which has an acid action characteristic other than aa). In such a resist composition, a resist pattern can be formed by the interaction between the resin (X) and the acid generator (B).

Among the resins (aa), a resin having such acid action characteristics is referred to as “resin (AA)”.
In the resin (AA), part or all of the hydrophilic group in the molecule is protected by a protective group that can be removed by contact with an acid. When the resin (AA) is in contact with an acid, the protective group is protected. Is released, and the resin (AA) becomes a resin soluble in an alkaline aqueous solution. The hydrophilic group protected by the protecting group is hereinafter referred to as “acid labile group”. Examples of the hydrophilic group include a hydroxy group or a carboxy group, and a carboxy group is more preferable. Similarly, the resin (X) does not have the structural unit (aa) and corresponds to a resin having an acid labile group in the molecule.

On the other hand, resin (aa) which has structural unit (aa) and does not have the above-mentioned acid action property is referred to as “resin (AB)”. Whether the resist composition contains the resin (AA) or the resin (AB) and the resin (X), the resist composition has an excellent line edge roughness (LER). Can be manufactured. Moreover, the latter present resist composition [the present resist composition containing the resin (AB) and the resin (X)] also exhibits the effect of producing a resist pattern with fewer defects.
In the resin (AA), the structural unit (aa) may have only one type or two or more types, and also in the resin (AB), the structural unit (aa) has only one type or two or more types. Also good.

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が互いに結合して形成される環又は該脂肪族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。 <Monomer (a1)>
The resin (AA) or the resin (X) is a resin obtained using a monomer having an acid labile group (hereinafter referred to as “monomer (a1)”) as a production material (monomer). As the monomer (a1), only one type may be used, or two or more types may be used. In addition, resin (AA) is obtained by manufacturing using a monomer (a1) with a compound (aa ').
In the case where the hydrophilic group is a carboxy group, the acid labile group is a group in which the hydrogen atom of the carboxy group is replaced with an organic residue, and the atom of the organic residue bonded to the oxy group is a tertiary carbon atom. (That is, an ester of a tertiary alcohol). 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 or the methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.

The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 1 to 16 carbon atoms.
Examples of the ring formed by combining R ^a1 and R ^a2 in —C (R ^a1 ) (R ^a2 ) (R ^a3 ) include those shown below. Such a ring preferably has 3 to 12 carbon atoms.

A specific example of such an acid labile group (1) is a 1,1-dialkylalkoxycarbonyl group (a group in which R ^{a1 to} R ^a3 are all alkyl groups in the formula (1), among these alkyl groups, 1 One is preferably a tert-butyl group.), 2-alkyladamantan-2-yloxycarbonyl group (in formula (1), R ^a1 and R ^a2 are bonded to each other and together with the carbon atom to which they are bonded, an adamantyl ring) Wherein 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 A group in which 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１〜１２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か、或いは、Ｒ^b2及びＲ^b3が結合して、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の環を形成する。この炭化水素基がメチレン基を含む場合、そのメチレン基は、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く、Ｒ^b2及びＲ^b3が結合して形成される環を構成するメチレン基も、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。 On the other hand, examples of the acid labile group in the case where the hydrophilic group is a hydroxy group include those in which a hydrogen atom of the hydroxy group is replaced with an organic residue, and a group containing an acetal structure or a ketal structure is obtained. Among such acid labile groups, preferred acid labile groups are, for example, those represented by the following formula (2) (hereinafter sometimes referred to as “acid labile groups (2)”).

In formula (2), R ^b1 and R ^b2 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^b3 represents a hydrocarbon group having 1 to 20 carbon atoms, or , R ^b2 and R ^b3 are combined to form a ring having 3 to 20 carbon atoms together with the carbon atom and oxygen atom to which they are bonded. When this hydrocarbon group contains a methylene group, the methylene group may be replaced by an oxygen atom, a sulfur atom or a carbonyl group, and the methylene group constituting the ring formed by combining R ^b2 and R ^b3 is also , Oxygen atom, sulfur atom or carbonyl group may be substituted.

The hydrocarbon group of R ^{b1 to} R ^b3 may be any of the above-described alkyl group, alicyclic hydrocarbon group, and aromatic hydrocarbon 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.
Of R ^b1 and R ^b2 , at least one is preferably a hydrogen atom.

Specific examples of the acid labile group (2) include the following groups.

The monomer (a1) having an acid labile group is preferably a monomer having an acid labile group and a carbon-carbon double bond, more preferably a (meth) acrylic monomer having an acid labile group.
The monomer (a1) is preferably a monomer having both an acid labile group (1) and / or an acid labile group (2) and a carbon-carbon double bond in the molecule, more preferably an acid labile. It is a (meth) acrylic monomer having a group (1).

Among the (meth) acrylic monomers having an acid labile group (1), a monomer (a1) having an acid labile group (1) having a partial structure of an alicyclic hydrocarbon having 5 to 20 carbon atoms is preferable.
The resin (AA) or resin (X) obtained by polymerizing the monomer (a1) having such a sterically bulky alicyclic hydrocarbon contains the resin (AA) or the resin (X). When a resist pattern is produced using this resist composition, the resist pattern can be produced with better resolution.

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。＊はカルボニル基（−ＣＯ−）との結合手である。）で表される基を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜１０の脂肪族炭化水素基を表す。
ｍ１は０〜１４の整数を表し、ｎ１は０〜１０の整数を表す。ｎ１’は０〜３の整数を表す。
なお、式（ａ１−１）においてアダマンタン環にある「−（ＣＨ_３）_ｍ１」の表記は、アダマンタン環に含まれるメチレン基及び／又はメチン基の水素原子が、メチル基に置き換わっており、アダマンタン環に結合しているメチル基の個数がｍ１個であることを意味する。同様に、式（ａ１−２）においてシクロヘキサン環にある「−（ＣＨ_３）_ｎ１」の表記は、シクロヘキサン環に含まれるメチレン基の水素原子が、メチル基に置き換わっており、シクロヘキサン環に結合しているメチル基の個数がｎ１個であることを意味する。 Among (meth) acrylic monomers having an acid labile group (1) having a partial structure of an alicyclic hydrocarbon, a monomer represented by the formula (a1-1) (hereinafter, “monomer (a1-1)”) Or a monomer represented by formula (a1-2) (hereinafter referred to as “monomer (a1-2)”). In the production of the resin (AA) or the resin (X), these may be used alone or in combination of two or more.

In formula (a1-1) and formula (a1-2),
L ^a1 and L ^a2 each independently represent an oxygen atom or ^* —O— (CH ₂ ) _k1 —CO—O— (k1 represents an integer of 1 to 7. * represents a carbonyl group (—CO—). Represents a bond).
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 an integer of 0 to 14, and n1 represents an integer of 0 to 10. n1 ′ represents an integer of 0 to 3.
In the formula (a1-1), the notation “— (CH ₃ ) _m1 ” in the adamantane ring means that the hydrogen atom of the methylene group and / or methine group contained in the adamantane ring is replaced with a methyl group. It means that the number of methyl groups bonded to the ring is m1. Similarly, in the formula (a1-2), the notation “— (CH ₃ ) _n1 ” in the cyclohexane ring indicates that the hydrogen atom of the methylene group contained in the cyclohexane ring is replaced with a methyl group, and is bonded to the cyclohexane ring. This means that the number of methyl groups present is n1.

In the formula (a1-1) and the formula (a1-2), L ^a1 and L ^a2 are preferably an 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 * —O—CH ₂ —CO—O—, and still more preferably an oxygen atom.
R ^a4 and R ^a5 are preferably methyl groups.
Of the aliphatic hydrocarbon groups of R ^a6 and R ^a7 , preferably an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and within the range of the upper limit of the carbon number, Includes those already exemplified. The aliphatic hydrocarbon groups for R ^a6 and R ^a7 are each independently preferably an alkyl group having 8 or less carbon atoms or an alicyclic hydrocarbon group having 8 or less carbon atoms, more preferably an alkyl group having 6 or less carbon atoms. Or it is an alicyclic hydrocarbon group having 6 or less 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.

As a monomer (a1-1), the following are mentioned, for example.

これらの中でも、モノマー（ａ１−１）としては、２−メチルアダマンタン−２−イル（メタ）アクリレート、２−エチルアダマンタン−２−イル（メタ）アクリレート及び２−イソプロピルアダマンタン−２−イル（メタ）アクリレートが好ましく、２−メチルアダマンタン−２−イルメタクリレート、２−エチルアダマンタン−２−イルメタクリレート及び２−イソプロピルアダマンタン−２−イルメタクリレートがより好ましい。

Among these, as the monomer (a1-1), 2-methyladamantan-2-yl (meth) acrylate, 2-ethyladamantan-2-yl (meth) acrylate and 2-isopropyladamantan-2-yl (meth) Acrylates are preferred, with 2-methyladamantan-2-yl methacrylate, 2-ethyladamantan-2-yl methacrylate and 2-isopropyladamantan-2-yl methacrylate being more preferred.

As a monomer (a1-2), the following are mentioned, for example.

これらの中でも、モノマー（ａ１−２）としては、１−エチルシクロヘキサン−１−イル（メタ）アクリレートが好ましく、１−エチルシクロヘキサン−１−イルメタクリレートがより好ましい。

Among these, as the monomer (a1-2), 1-ethylcyclohexane-1-yl (meth) acrylate is preferable, and 1-ethylcyclohexane-1-yl methacrylate is more preferable.

  When the resin (X) is produced using the monomer (a1-1) and / or the monomer (a1-2), when the total structural unit of the obtained resin (X) is 100 mol%, it is derived from these monomers. The total content of structural units (content of structural units derived from these monomers) 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 bring the total content of the structural units derived from the monomer (a1-1) and / or the structural units derived from the monomer (a1-2) into such a range, when producing the resin (X) In addition, the total use amount of the monomer (a1-1) and / or the monomer (a1-2) with respect to the use amount of all monomers may be adjusted. In addition, when resin (AA) has a structural unit derived from the monomer (a1-1) and / or a structural unit derived from the monomer (a1-2), the total content ratio thereof is the total of the resin (AA). The range of 10-95 mol% is preferable with respect to the structural unit (100 mol%), the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is more preferable.

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−ＣＯＯＲ^a13（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に含まれる水素原子は、ヒドロキシ基に置換されていてもよく、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、脂肪族炭化水素基に含まれる水素原子は、ヒドロキシ基などに置換されていてもよく、これらの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。 Resin (AA) or resin (X) may contain structural units derived from other monomers having an acid labile group and a carbon-carbon double bond in the molecule in addition to the (meth) acrylic monomer. Good.
Examples of the other monomer (a1) include a monomer having a norbornene ring represented by the following formula (a1-3) (hereinafter sometimes referred to as “monomer (a1-3)”). The structural unit derived from the monomer (a1-3) has an acid labile group (1).

In formula (a1-3),
R ^a9 is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms that may have a hydroxy group, a carboxyl group, a cyano group, or —COOR ^a13 (R ^a13 is an aliphatic hydrocarbon group having 1 to 20 carbon atoms. Wherein a hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group, and a methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ).
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, A hydrogen atom contained in an aliphatic hydrocarbon group that forms a ring of 3 to 20 may be substituted with a hydroxy group or the like, and a methylene group constituting these groups is replaced with an oxygen atom or a carbonyl group. May be.

Examples of the alkyl group having a hydroxy group include a hydroxymethyl group and a 2-hydroxyethyl group.
R ^a13 in groups -COOR ^a13 is preferably an alicyclic hydrocarbon group of the alkyl group or 3 to 20 carbon atoms having 1 to 8 carbon atoms.
The ring formed by combining R ^a10 and R ^a11 is preferably an alicyclic hydrocarbon, and specific examples include a cyclohexane ring and an adamantane ring.

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

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

  As described above, the monomer (a1) with respect to the total structural unit (100 mol%) of the resin (AA) in that a resist pattern with good resolution can be produced and a resist pattern excellent in dry etching resistance can be easily obtained. The content ratio of the structural unit derived from -3) 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 10 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (X). Is preferable, the range of 15 to 90 mol% is more preferable, and the range of 20 to 85 mol% is more preferable.

式（ａ１−４）中、
Ｒ^a32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^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以上の場合、複数のＲ^a33は同一でも異なっていてもよい。
Ｒ^a34及びＲ^a35はそれぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表す。
Ｘ^a2は、単結合又は炭素数１〜１７の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基又は炭素数２〜４のアシルオキシ基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、硫黄原子、カルボニル基、スルホニル基（−ＳＯ_２−）又は−Ｎ（Ｒ^ｃ）−で示される基に置き換わっていてもよい。Ｒ^ｃは、水素原子又は炭素数１〜６のアルキル基を表す。
Ｙ^a3は、炭素数１〜１８の炭化水素基を表し、該炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基又は炭素数２〜４のアシルオキシ基に置換されていてもよい。 As the other monomer (a1), a monomer represented by the following formula (a1-4) (hereinafter may be referred to as “monomer (a1-4)”) may also be used. The structural unit derived from the monomer (a1-4) has an acid labile group (2).

In formula (a1-4),
R ^a32 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or 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 may be the same or different.
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 single bond or an aliphatic hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the aliphatic hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, carbon The methylene group which may be substituted by 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 is an oxygen atom, sulfur It may be replaced by a group represented by an atom, a carbonyl group, a sulfonyl group (—SO ₂ —) or —N (R ^c ) —. R ^c represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Y ^a3 represents a hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. , May be substituted with an acyl group having 2 to 4 carbon atoms or an acyloxy group having 2 to 4 carbon atoms.

  Examples of the alkyl group which may have a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. Group, perfluorohexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group and the like.

  In the formula (a1-4), the alkyl group is preferably an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group or a 2-ethylhexyl group. As the alicyclic hydrocarbon group, a cyclohexyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, an isobornyl group, and the like are preferable. As aromatic hydrocarbon group, phenyl group, naphthyl group, anthranyl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl Group, anthryl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl and the like are preferable.

In particular, R ^a32 and R ^a33 are 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.
R ^a33 is more preferably a methoxy group or an ethoxy group, and particularly preferably a methoxy group.
The R ^a34 and R ^a35, isopropyl group, n- butyl group, sec- butyl group, tert- butyl group, a pentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, a cyclohexyl group, an adamantyl group, 2-alkyl - A 2-adamantyl group, a 1- (1-adamantyl) -1-alkyl group, an isobornyl group, and the like are preferable.
The aliphatic hydrocarbon group for X ^a2 is preferably a chain hydrocarbon group, and more preferably an aliphatic saturated hydrocarbon group.
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.
The substituent for X ^a2 and Y ^a3 is preferably a hydroxy group.

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

  When the resin (AA) 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 (AA). 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、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。
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 other monomer (a1), for example, a monomer represented by the formula (a1-5) which is a (meth) acrylic monomer having an acid labile group (2) (hereinafter referred to as “monomer (a1-5)”) May be used).

In formula (a1-5),
R ³¹ represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or 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, or a trifluoromethyl 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.
s1 ′ is preferably an integer of 0 to 2.
Z ¹ is preferably a single bond or —CH ₂ —CO—O—.

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

  When the resin (AA) 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 (AA). 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.

<Acid stable monomer>
Resin (AA) is a copolymer obtained by copolymerizing a monomer having no acid labile group (hereinafter sometimes referred to as “acid-stable monomer”) in addition to compound (aa ′) and monomer (a1). A polymer is preferred. Resin (X) is also preferably a copolymer obtained by copolymerizing an acid stable monomer in addition to monomer (a1).
Moreover, as resin (AB), the resin obtained by copolymerizing the acid stable monomer mentioned later and compound (aa ') is preferable.

  When the resin (X) is produced using an acid-stable monomer, the amount of the acid-stable monomer may be determined based on the amount of the monomer (a1) used. The ratio of the amount of monomer (a1) used and the amount of acid-stable monomer used is represented by [monomer (a1)] / [acid-stable monomer], preferably 10 to 80 mol% / 90 to 20 mol%, More preferably, it is 20-60 mol% / 80-40 mol%. Similarly, when the resin (AA) is produced, the preferred amount of the acid-stable monomer can be determined based on the amount of the monomer (a1) used. In this case, the compound (aa ′) The amount of the acid-stable monomer may be included in the amount of the acid-stable monomer used to determine the amount of the acid-stable monomer used.

  Examples of the acid stable monomer include those having a hydroxy group or a lactone ring. Derived from an acid-stable monomer having a hydroxy group (hereinafter sometimes referred to as “acid-stable monomer (a2)”) and / or an acid-stable monomer having a lactone ring (hereinafter sometimes referred to as “acid-stable monomer (a3)”). The resin (AA) or resin (X) having a structural unit is a coating film or coating formed on the substrate when the resist composition containing the resin (AA) or the resin (X) is applied to the substrate. The composition layer obtained from the film is likely to exhibit excellent adhesion with the substrate. In addition, this resist composition can produce a resist pattern with good resolution. Similarly, the present resist composition containing the acid-stable monomer (a2) and / or the resin (AB) having the acid-stable monomer (a3) also easily exhibits excellent adhesion between the composition layer and the substrate. .

<Acid stable monomer (a2)>
Resist composition selected from the group consisting of Resin (AA), Resin (AB) or Resin (X) [Hereinafter, Resin (AA), Resin (AB) and Resin (X) depending on the case) acid stable monomer (a2) The resin for preparing the product is referred to as “this resist resin”. In the case of use in the production of a resist pattern, a suitable acid-stable monomer (a2) is used depending on the type of exposure source when producing a resist pattern from the present resist composition containing any one of these resins. Or two or more types can be selected. That is, when this 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 as an exposure source, the acid stable monomer (a2) As an acid-stable monomer (a2-0) [for example, hydroxystyrenes] having a phenolic hydroxy group, it is preferable to use for the production of the resist resin. When exposure using a short wavelength ArF excimer laser (wavelength: 193 nm) as an exposure source is used, an acid stable monomer represented by the formula (a2-1) described later is used as the acid stable monomer (a2) of the resist resin. It is preferable to use for manufacture.

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以上の場合、複数のＲ^a31は同一でも異なっていてもよい。 As the acid stable monomer (a2), a styrene monomer such as p- or m-hydroxystyrene represented by the following formula (a2-0) (hereinafter sometimes referred to as “acid stable monomer (a2-0)”) Is mentioned.

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 2 or more, the plurality of R ^a31 may be the same or different.

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.

  When producing this resist resin having a structural unit derived from the acid stable monomer (a2-0), a monomer in which the phenolic hydroxy group in the acid stable monomer (a2-0) is protected with a protecting group may be used. it can. As the protecting group, for example, a protecting group capable of leaving with an acid or a base is preferable. A phenolic hydroxy group protected with a protecting group capable of leaving with an acid or a base can be deprotected by contact with an acid or a base. However, since the resin (AA) or the resin (X) has a structural unit derived from the monomer (a1) having an acid labile group as described above, the phenolic hydroxy group is protected with a protective group. When deprotecting the structural unit derived from the monomer, it is preferable to deprotect by contact with a base so that the acid labile group is not significantly impaired. 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.

Examples of the acid stable monomer (a2-0) include the following monomers.

  Among the above acid-stable monomers (a2-0), 4-hydroxystyrene or 4-hydroxy-α-methylstyrene is particularly preferable.

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。＊はカルボニル基（−ＣＯ−）との結合手を表す。）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。 As the acid stable monomer (a2), a monomer represented by the formula (a2-1) (hereinafter may be referred to as “acid stable monomer (a2-1)”) may also be used.

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. * represents a bond to 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, k2 is an integer of from 1 to 4 _{-O- (CH 2) k2 -CO-} O- , a group represented by the more Preferably, it is an oxygen atom or —O—CH ₂ —CO—O—, and 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.

Examples of the acid stable monomer (a2-1) include the following. Among these, 3-hydroxyadamantan-1-yl (meth) acrylate, 3,5-dihydroxyadamantan-1-yl (meth) acrylate and (meth) acrylic acid 1- (3,5-dihydroxyadamantan-1-yl Oxycarbonyl) methyl is preferred, 3-hydroxyadamantan-1-yl (meth) acrylate and 3,5-dihydroxyadamantan-1-yl (meth) acrylate are more preferred, 3-hydroxyadamantan-1-yl methacrylate and 3, More preferred is 5-dihydroxyadamantan-1-yl methacrylate.

  When the resist resin has a structural unit derived from the acid-stable monomer (a2-1), the content ratio is preferably in the range of 3 to 40 mol% with respect to the total structural unit (100 mol%) of the resin. The range of 5 to 35 mol% is more preferable, and the range of 5 to 30 mol% is more preferable.

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

式（ａ３−１）、式（ａ３−２）及び式（ａ３−３）において、
Ｌ^a4〜Ｌ^a6は、それぞれ独立に、酸素原子又は＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。＊はカルボニル基（−ＣＯ−）との結合手を表す。）を表す。
Ｒ^a18〜Ｒ^a20は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a21は、炭素数１〜４のアルキル基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a22及びＲ^a23は、それぞれ独立に、カルボキシ基、シアノ基又は炭素数１〜４のアルキル基を表す。
ｑ１及びｒ１は、それぞれ独立に０〜３の整数を表す。ｐ１が２以上の場合、複数のＲ^a21は同一でも異なっていてもよく、ｑ１が２以上の場合、複数のＲ^a22は同一でも異なっていてもよく、ｒ１が２以上の場合、複数のＲ^a23は同一でも異なっていてもよい。 The acid stable monomer (a3) is preferably one represented by the following formula (a3-1), formula (a3-2) or formula (a3-3). In this resist resin manufacture, only 1 type may be used among these and 2 or more types may be used together. In the following description, the acid stable monomer (a3) represented by the formula (a3-1) may be referred to as “acid stable monomer (a3-1)”, and the acid stability represented by the formula (a3-2) may be referred to. The monomer (a3) may be referred to as “acid-stable monomer (a3-2)”, and the acid-stable monomer (a3) represented by formula (a3-3) may be referred to as “acid-stable monomer (a3-3)”. .

In formula (a3-1), formula (a3-2) and 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 carbonyl group (—CO—). Represents a bond.)
R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents an alkyl group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or an alkyl group having 1 to 4 carbon atoms.
q1 and r1 each independently represents an integer of 0 to 3. When p1 is 2 or more, a plurality of R ^a21 may be the same or different. When q1 is 2 or more, a plurality of R ^a22 may be the same or different. When r1 is 2 or more, a plurality of R ^{a21 a23} may be the same or different.

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 each independently preferably an integer of 0 to 2, more preferably 0 or 1.

As an acid stable monomer (a3-1), the following are mentioned, for example.

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

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

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

  Among the resist resins, acid-stable monomers (a4), acid-stable monomers (a5), acid-stable monomers (a6), acid-stable monomers that can be used for the production of resins (AA) and resins (AB) A monomer (a7), an acid stable monomer (a8), and an acid stable monomer (a9) can be mentioned. These acid stable monomers can be copolymerized with the compound (aa ′) and the monomer (a1) to produce a resin (AA). Moreover, these acid stable monomers are preferable for copolymerizing with the compound (aa ′) to produce the resin (AB) without using the monomer (a1).

［式（３）中、Ｒ¹⁰は、炭素数１〜６のフッ化アルキル基を表す。］ <Acid-stable monomer (a4)>
The acid stable monomer (a4) has a group represented by the following formula (3).

[In Formula (3), R ¹⁰ represents a fluorinated alkyl group having 1 to 6 carbon atoms. ]

  The fluorinated alkyl group is a difluoromethyl group, trifluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 1,1 , 2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2-tetrafluoro Ethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3,4 , 4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1, , 2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1 -Bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2,2,3,3,4 4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group and perfluorohexyl group Can be mentioned.

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 trifluoromethyl group. preferable.

As an acid stable monomer (a4) which has group represented by Formula (3), what is represented by the following is mentioned, for example.

When the resin (AA) has a structural unit derived from the acid-stable monomer (a4), the content ratio is in the range of 1 to 30 mol% with respect to the total structural unit (100 mol%) of the resin (AA). The range of 3 to 25 mol% is preferable, and the range of 5 to 20 mol% is more preferable.
Further, when the resin (AB) has a structural unit derived from a structural unit derived from the acid-stable monomer (a4), the content thereof is based on the total structural unit (100 mol%) of the resin (AB). It is selected from the range of 5 to 90 mol%, preferably 10 to 80 mol%, more preferably 20 to 70 mol%.

［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^２は、単結合、−（ＣＨ_２）_ｍ10−ＳＯ_２−Ｏ−＊又は−（ＣＨ_２）_ｍ10−ＣＯ−Ｏ−＊を表し、ここに示すアルキレン鎖〔−（ＣＨ_２）_ｍ10−〕に含まれるメチレン基は、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、当該アルキレン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。］ <Acid-stable monomer (a5)>
The acid stable monomer (a5) has a group represented by the following formula (4).

Wherein (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 ² represents a single bond, — (CH ₂ ) _{m 10} —SO ₂ —O— * or — (CH ₂ ) _{m 10} —CO—O— *, and an alkylene chain [— (CH ₂ ) _{m 10} —] shown here. The methylene group contained in may be replaced with an oxygen atom, a carbonyl group or a sulfonyl group, and the hydrogen atom contained in the alkylene chain may be replaced with a fluorine atom.
m10 represents an integer of 1 to 12. ]

Examples of the hetero atom include a halogen atom, a sulfur atom, an oxygen atom, and a nitrogen atom.
In the formula (4), examples of the substituent in R ¹¹ and R ¹² include 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- group. A butylphenyl group etc. are mentioned.

Preferred examples of R ¹¹ are shown below. Note that * is a bond with a carbon atom.

When the hydrocarbon group for R ¹² includes a hetero atom, the linking group may include a sulfonyl group or a carbonyl group.
Examples of R ¹² containing such a heteroatom include the following groups.

A ² includes the following groups.

［式（ａ５−１）中、Ｒ¹³は、水素原子又はメチル基を表す。その他の符号はいずれも、前記と同義である。］ Examples of the acid stable monomer (a5) containing a group represented by the formula (3) include a monomer represented by the formula (a5-1) (hereinafter sometimes referred to as “acid stable monomer (a5-1)”). Is mentioned.

[In the formula (a5-1), R ¹³ represents a hydrogen atom or a methyl group. All other symbols are as defined above. ]

As an acid stable monomer (a5-1), what is represented by the following is mentioned, for example.

When the resin (AA) has a structural unit derived from the acid-stable monomer (a5-1), the content is 1 to 30 mol% with respect to the total structural unit (100 mol%) of the resin (AA). The range of 3 to 25 mol% is preferable, and the range of 5 to 20 mol% is more preferable.
Moreover, when resin (AB) has a structural unit derived from the structural unit derived from an acid stable monomer (a5-1), the content is with respect to all the structural units (100 mol%) of resin (AB). The range is 5 to 90 mol%, preferably 10 to 80 mol%, more preferably 20 to 70 mol%.

式（ａ６−１）中、
Ｗ^１は、炭素数３〜３６の脂環式炭化水素を表す。
Ａ^３は、単結合又は炭素数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、ハロゲン原子を有していてもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ¹⁵及びＲ¹⁶は、それぞれ独立に、ハロゲン原子を有していてもよい炭素数１〜６のアルキル基を表す。 <Acid stable monomer (a6)>
The acid stable monomer (a6) is a (meth) acrylic monomer having an aliphatic ring in its molecule (hereinafter referred to as “acid stable monomer (a6-1)”) as represented by the following formula (a6-1). May be).

In formula (a6-1),
W ¹ represents an alicyclic hydrocarbon having 3 to 36 carbon atoms.
A ³ represents an aliphatic hydrocarbon group of a single bond or a C 1-17 methylene groups contained in the aliphatic hydrocarbon group may but be replaced by an oxygen atom or a carbonyl group, the A ³ Of these, the atom bonded to the oxygen atom is a carbon atom.
R ¹⁴ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
R ¹⁵ and R ¹⁶ each independently represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.

で示される部分構造は、式（ＫＡ−１）〜式（ＫＡ−２２）で示した脂環式炭化水素に含まれる１個の水素原子がＡ^３との結合手に、脂環式炭化水素の環に含まれる炭素原子の１つに結合している２つの水素原子がそれぞれ、−Ｏ−ＣＯ−Ｒ¹⁵及び−Ｏ−ＣＯ−Ｒ¹⁶との結合手に置き換わったものが好ましい。
Ｗ^１の脂環式炭化水素は、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好ましい。 W ¹ is a monocyclic or polycyclic aliphatic ring having 3 to 36 carbon atoms, preferably 5 to 18 carbon atoms, more preferably 6 to 12 carbon atoms. That is, in formula (a6-1)

In the partial structure represented by the formula (KA-1) to the formula (KA-22), one hydrogen atom contained in the alicyclic hydrocarbon represented by the formula (KA-22) has a bond with A ³ as the alicyclic hydrocarbon. It is preferable that two hydrogen atoms bonded to one of the carbon atoms contained in the ring are replaced with bonds to —O—CO—R ¹⁵ and —O—CO—R ¹⁶ , respectively.
The alicyclic hydrocarbon of W ¹ is preferably a cyclohexane ring, an adamantane ring, a norbornane ring or a norbornene ring.

式（Ｘ^ｘ−Ａ）、式（Ｘ^ｘ−Ｂ）及び式（Ｘ^ｘ−Ｃ）中、
Ｘ^x1及びＸ^x2は、それぞれ独立に、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単結合を表し、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。 When an aliphatic hydrocarbon group obtained by combining an alkanediyl group and an alicyclic hydrocarbon group as the aliphatic hydrocarbon group for A ³ is zero, the following formulas (X ^x -A) and (X ^x -B) And a group represented by the formula (X ^x -C).

In formula (X ^x -A), formula (X ^x -B) and formula (X ^x -C),
X ^x1 and X ^x2 each independently represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms or a single bond, and X ^x1 and X ^x2 are not both 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.

Examples of the group in which the methylene group constituting the aliphatic hydrocarbon group for A ³ is replaced by an oxygen atom or a carbonyl group include those exemplified for the group (a-1) in the formula (aa).
A ³ is preferably a single bond or a group represented by * — (CH ₂ ) _s1 —CO—O— (* represents a bond with —O—, and s1 represents an integer of 1 to 6). , A single bond or * —CH ₂ —CO—O— is more preferable.

In R ^{14 to} R ¹⁶ , the halogen atom is particularly preferably a fluorine atom.
Of the alkyl groups having a halogen atom in R ^{14 to} R ¹⁶ , preferred are a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, and the like, and among them, a trifluoromethyl group, a perfluoro group, and the like. Ethyl and perfluoropropyl groups are preferred.
R ¹⁴ is preferably a hydrogen atom or a methyl group.

The acid stable monomer (a6-1) is as shown below. R ^{14 to} R ¹⁶ and A ³ are as defined above.

で示される酸安定モノマー（ａ６−１）がより好ましい。 Among these,

The acid stable monomer (a6-1) shown by these is more preferable.

As the acid stable monomer (a6-1), the following monomers are preferable.

［式（ａ６−１−ａ）及び式（ａ６−１−ｂ）中の符号はいずれも、前記と同義である。］ The acid-stable monomer (a6-1) can be produced, for example, by reacting a compound represented by the formula (a6-1-a) with a compound represented by the formula (a6-1-b). it can. This reaction is preferably performed by heating near the boiling point of the compound represented by the formula (a6-1-b) to be used.
Examples of the compound represented by the formula (a6-1-a) include 1-methacryloyloxy-4-oxoadamantane described in JP-A-2002-226436.
Examples of the compound represented by the formula (a6-1-b) include pentafluoropropionic anhydride, heptafluorobutyric anhydride, and trifluoroacetic anhydride.

[The symbols in formulas (a6-1-a) and (a6-1-b) are as defined above. ]

When the resin (AA) has a structural unit derived from the acid-stable monomer (a6-1), the content is 1 to 30 mol% with respect to the total structural unit (100 mol%) of the resin (AA). The range of 3 to 25 mol% is preferable, and the range of 5 to 20 mol% is more preferable.
Moreover, when resin (AB) has a structural unit derived from an acid stable monomer (a6-1), the content is 5 to 90 with respect to all the structural units (100 mol%) of resin (AB). It is selected from the range of mol%, preferably in the range of 10-80 mol%, more preferably in the range of 20-70 mol%.

式（ａ７−３）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−ＣＯＯＲ^a27〔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に含まれるメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。但し−ＣＯＯＲ^a27が酸不安定基となるものは除く（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は互いに結合して−ＣＯ−Ｏ−ＣＯ−を形成する。 <Acid-stable monomer (a7)>
As the acid stable monomer (a7), maleic anhydride represented by the formula (a7-1), itaconic anhydride represented by the formula (a7-2), and norbornene represented by the formula (a7-3) And an acid-stable monomer having a ring (hereinafter sometimes referred to as “acid-stable monomer (a7-3)”).

In formula (a7-3),
R ^a25 and R ^a26 each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms that may have a hydroxy group, a cyano group, a carboxy group, or —COOR ^a27 [R ^a27 represents 1 to 1 carbon atoms; 18 represents an aliphatic hydrocarbon group, and the methylene group contained in 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 Bond to each other to form -CO-O-CO-.

In formula (a7-3),
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 (a7-3) having a norbornene ring include 2-norbornene, 2-hydroxy-5-norbornene, 5-norbornene-2-carboxylic acid, methyl 5-norbornene-2-carboxylate, 5- Examples include norbornene-2-carboxylic acid 2-hydroxy-1-ethyl, 5-norbornene-2-methanol, and 5-norbornene-2,3-dicarboxylic acid anhydride.

The resin (AA) is a structural unit derived from maleic anhydride represented by the formula (a7-1), a structural unit derived from itaconic anhydride represented by the formula (a7-2), and an acid stable monomer (a7- 3) When having a structural unit selected from the group consisting of structural units derived from [structural unit derived from acid-stable monomer (a7)], the total content is 100% by mole of all structural units of resin (AA). ) Is selected from the range of 2 to 40 mol%, preferably 3 to 30 mol%, more preferably 5 to 20 mol%.
The resin (AB) is a structural unit derived from maleic anhydride represented by the formula (a7-1), a structural unit derived from itaconic anhydride represented by the formula (a7-2), and an acid stable monomer ( When having a structural unit selected from the group consisting of structural units derived from a7-3) [structural unit derived from acid-stable monomer (a7)], the total content is 100% of all structural units of resin (AB) (100 Is selected from the range of 5 to 70 mol%, preferably 10 to 60 mol%, and more preferably 20 to 50 mol%.

式（ａ７−４）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。 The acid stable monomer (a7) may be, for example, a monomer having a sultone ring represented by the formula (a7-4) (hereinafter sometimes referred to as “acid stable monomer (a7-4)”).

In formula (a7-4),
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.

Examples of the sultone ring contained in the sultone ring group include one in which one of the adjacent methylene groups contained in the alicyclic hydrocarbon is replaced by an oxygen atom and the other is a sulfonyl group. . A typical example of a sultone ring group is one in which one of the hydrogen atoms contained in the following sultone ring is replaced with a bond, and in formula (a7-4), the bond with L ^a7 corresponds.

  The sultone ring group which may have a substituent is a group in which a hydrogen atom other than a hydrogen atom replaced with the above bond is further replaced with a substituent (a monovalent group other than a hydrogen atom), The substituent is a hydroxy group, a cyano group, an alkyl group having 1 to 6 carbon atoms, a fluorinated alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, carbon It is selected from the group consisting of 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.

  Examples of the acid stable monomer (a7) having a sultone ring represented by the formula (a7-4) include the following.

In the example of the formula (a7-4) described above, a structure in which the partial structure (V) shown below is replaced with the partial structure (P) shown below can also be given as a specific example of the formula (a7-4). .

When the resin (AA) has a structural unit derived from the acid-stable monomer (a7) represented by the formula (a7-4), the content ratio is the total structural unit (100 mol%) of the resin (AA). On the other hand, it is selected from the range of 2 to 40 mol%, preferably 3 to 35 mol%, more preferably 5 to 30 mol%.
Further, when the resin (AB) has a structural unit derived from the acid stable monomer (a7) represented by the formula (a7-4), the content ratio is all structural units (100 mol%) of the resin (AB). ) Is selected from a range of 5 to 90 mol%, preferably 10 to 80 mol%, more preferably 20 to 70 mol%.

<Acid stable monomer (a8)>
Examples of the acid stable monomer (a8) include a monomer having a fluorine atom as shown below [hereinafter referred to as “acid stable monomer (a8)”. ].

Among these monomers, (meth) acrylic acid 5- (3,3,3-trifluoro-2-hydroxy-2- [trifluoromethyl] propyl) having a monocyclic or polycyclic alicyclic group Bicyclo [2.2.1] hept-2-yl, (meth) acrylic acid 6- (3,3,3-trifluoro-2-hydroxy-2- [trifluoromethyl] propyl) 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 (AA) has a structural unit derived from the acid-stable monomer (a8), the total content is 1 to 20 mol% with respect to the total structural unit (100 mol%) of the resin (AA). The range is selected, preferably 2 to 15 mol%, more preferably 3 to 10 mol%.
Moreover, when resin (AB) has the structural unit derived from an acid stable monomer (a8), the total content rate is 5-90 mol with respect to all the structural units (100 mol%) of resin (AB). %, Preferably in the range of 10 to 80 mol%, more preferably in the range of 20 to 70 mol%.

<Acid-stable monomer (a9)>
Examples of the acid stable monomer (a9) include a monomer monomer having a fluorinated alkylcarbonyloxy group or a fluorinated alkyloxycarbonyl group as shown below [hereinafter referred to as “acid stable monomer (a9)”. ].

Among such monomers, the following monomers are preferable.

When the resin (AA) has a structural unit derived from the acid-stable monomer (a9), the total content is 1 to 20 mol% with respect to the total structural unit (100 mol%) of the resin (AA). The range is selected, preferably 2 to 15 mol%, more preferably 3 to 10 mol%.
Moreover, when resin (AB) has the structural unit derived from an acid stable monomer (a9), the total content rate is 5-90 mol with respect to all the structural units (100 mol%) of resin (AB). %, Preferably in the range of 10 to 80 mol%, more preferably in the range of 20 to 70 mol%.

<Production method of resin>
The resin (AA) is obtained by copolymerizing the compound (aa ′), the monomer (a1), and, if necessary, an acid stable monomer, and more preferably the compound (aa ′), the monomer ( a1) and an acid stable monomer (a2) and / or an acid stable monomer (a3) are copolymerized. In producing the resin (AA), it is preferable to use at least one of the monomer (a1-1) having an adamantyl group and the monomer (a1-2) having a cyclohexyl group as the monomer (a1). It is more preferable to use a monomer having an adamantyl group (monomer (a1-1)). As the acid stable monomer, it is preferable to use an acid stable monomer (a2-1) having a hydroxyadamantyl group and an acid stable monomer (a3). As the acid stable monomer (a3), it is preferable to use at least one of a monomer (a3-1) having a γ-butyrolactone ring and a monomer (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring. .

The content of the structural unit derived from the monomer (a1) with respect to the total structural unit (100 mol%) of the resin (AA) has already been described for each of the monomer (a1-1) and the monomer (a1-2). The total of these, that is, the structural unit derived from the monomer (a1) is preferably in the range of 10 to 80 mol%, more preferably 20 to 20%, based on the total structural unit (100 mol%) of the resin (aa). The range is 60 mol%.
The content of the structural unit (aa) is preferably in the range of 1 to 30 mol%, more preferably in the range of 3 to 10 mol% with respect to the total structural units (100 mol%) of the resin (AA). is there.
When a monomer having an adamantyl group (particularly monomer (a1-1)) is used, the structural unit derived from the monomer having an adamantyl group is based on the total (100 mol%) of the structural units derived from the monomer (a1). It is preferable to be 15 mol% or more. If it does in this way, there exists a tendency for the dry etching tolerance of the resist pattern obtained from this resist composition containing resin (AA) to become more favorable.

  The weight average molecular weight of the resin (AA) is preferably 2,500 or more and 50,000 or less, and more preferably 3,000 or more and 30,000 or less. In this specification, a weight average molecular weight is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis, and the detailed analysis conditions of this analysis are explained in full detail in the Example of this application.

The resin (AB) is a group consisting of an acid stable monomer (a4), an acid stable monomer (a5), an acid stable monomer (a6), an acid stable monomer (a7), an acid stable monomer (a8), and an acid stable monomer (a9). Those obtained by copolymerizing an acid stable monomer selected from the compound (aa ′) are preferable, and those obtained by copolymerizing the acid stable monomer (a9) and the compound (aa ′) are more preferable.
In the resin (AB), the ratio between the amount of compound (aa ′) used and the total amount of monomers (a4) to (a9) used is [compound (aa ′)] / [monomer (a4) to monomer ( a
9), preferably 5 to 100 mol% / 0 to 95 mol%, more preferably 20 to 100 mol% / 0 to 80 mol%, and particularly preferably 50 to 100 mol%. / 0 to 50 mol%.

  The weight average molecular weight of the resin (AB) is preferably from 8,000 to 80,000, more preferably from 10,000 to 60,000.

The resin (X) is preferably, for example, one obtained by polymerizing at least one monomer (a1) or copolymerizing the monomer (a1) with the acid stable monomer (a2) and / or the acid stable monomer (a3). The monomer (a1) used for the production of the resin (X) is preferably at least one of a monomer (a1-1) having an adamantyl group and a monomer (a1-2) having a cyclohexyl group, and has an adamantyl group. Monomer (a1-1) is more preferable. The acid stable monomer (a2) used for the production of the resin (X) is preferably a monomer (a2-1) having a hydroxyadamantyl group, and the acid stable monomer (a3) is a monomer having a γ-butyrolactone ring (a3-1) And at least one monomer (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring is preferable.
The weight average molecular weight of the resin (X) is preferably 2,500 or more (more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less).
In the resin (X), the ratio of the amount of the monomer (a1) used to the total amount of the monomer (a2) and / or the monomer (a3) is [monomer (a1)] / [monomer (a2) + monomer ( The total of a3)] is preferably 10 to 80 mol% / 20 to 90 mol%, and more preferably 20 to 60 mol% / 40 to 80 mol%.

  Resin (AA), resin (AB) and resin (X) can be produced by selecting necessary monomers and then subjecting these monomers to a known polymerization method (for example, radical polymerization method).

<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 (B) include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent 3914407, European Patent 126,712. The compound which generate | occur | produces an acid by the radiation described in No. etc. 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、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 (B) contained in the resist composition is preferably an acid generator represented by the following formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”). In the following description, among the acid generators (B1), Z ⁺ having a positive charge is referred to as “organic cation”, and a negative charge obtained by removing the organic cation is referred to as “sulfonate anion”. That's it.

In formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents an ^optionally substituted divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group is replaced with an oxygen atom or a carbonyl group. It may be.
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.

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し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
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し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b4は、炭素数１〜１３の２価の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但し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し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
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、これらの脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但し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し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
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、これらの脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b9及びＬ^b10の合計炭素数の上限は１２である。 An example in which the methylene group constituting the aliphatic hydrocarbon group of L ^b1 is replaced with an oxygen atom or a carbonyl group is represented by any of the following formulas (b1-1) to (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). In addition, * represents a bond, one is bonded to Y, and the other is 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 C 1-15 divalent aliphatic hydrocarbon group, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b3 represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b4 represents a divalent aliphatic hydrocarbon group having 1 to 13 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group. However, 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, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b6 and L ^b7 each independently represent a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, 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, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b9 and L ^b10 each independently represent a divalent aliphatic hydrocarbon group having 1 to 11 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12.

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

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

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

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

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

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

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.
Of these, a group represented by the formula (b1-1) is preferable, and a group represented by the formula (b1-1) in which L ^b2 is a single bond or a methylene group is more preferable.

The aliphatic hydrocarbon group for L ^b1 may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, a carboxy group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, and a glycidyloxy group. Is mentioned.

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 carbon group having 3 to 12 carbon atoms. A hydrogen group is particularly preferred.
Examples of the substituent 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, and 7 to 21 carbon atoms. An aralkyl group, 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 a hydrocarbon having 1 to 16 carbon atoms) And j2 represents an integer of 0 to 4). These aromatic hydrocarbon group and aralkyl group may further have an alkyl group, a halogen atom or a hydroxy group.

  In Y, examples of the group in which the methylene group constituting the aliphatic hydrocarbon group is replaced by an oxygen atom, a sulfonyl group, or a carbonyl group include, for example, a cyclic ether structure (one of the methylene groups constituting the alicyclic hydrocarbon group or A group in which two oxygen atoms are replaced), a cyclic ketone group (a group in which one or two methylene groups constituting the alicyclic hydrocarbon group are replaced by carbonyl groups), a sultone ring group (an alicyclic hydrocarbon group). Two methylene groups adjacent to each other among the methylene groups constituting the methylene groups constituting the alicyclic hydrocarbon group, and two adjacent methylene groups replaced with an oxygen atom and a sulfonyl group, respectively. Are groups in which an oxygen atom and a carbonyl group are substituted, respectively.

Among the alicyclic hydrocarbon groups of Y, preferred groups are alicyclic hydrocarbon groups represented by any of the following formulas (Y1) to (Y5), and among these, the formula (Y1 ) To alicyclic hydrocarbon groups represented by any one of formulas (Y3) and (Y5) are more preferred, and alicyclic hydrocarbon groups represented by formula (Y1) or formula (Y2) are particularly preferred. . The hydrogen atom contained in these alicyclic hydrocarbon groups may be substituted with a substituent.

As the alicyclic hydrocarbon group having a substituent, for example, the following are preferable.

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.

  Among them, the alicyclic hydrocarbon group of Y is preferably a group having an adamantane ring like those represented by the formulas (Y1) and (Y2), and when these have a substituent, the substituent is a hydroxy group. Is preferred. That is, Y is particularly preferably a substituted alicyclic hydrocarbon group, particularly a hydroxyadamantyl group.

Specific examples of the sulfonate anion include sulfonate anions represented by formulas (b1-1-1) to (b1-1-9) ”. In the sulfonate anion represented by any one of formulas (b1-1-1) to (b1-1-9), L ^b1 is preferably a group represented by 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 particularly preferred.

  Examples of the sulfonate anion represented by any one of formulas (b1-1-1) to (b1-1-9) include sulfonate anions described in JP 2010-204646 A. it can.

Specific examples are shown in which L ^b1 is a group represented by the formula (b1-1), and Y is an alicyclic hydrocarbon group represented by the formula (Y1) or the formula (Y2).
Examples of the sulfonate anion in which Y is an unsubstituted alicyclic hydrocarbon group include those represented by any of the following formulas (b1-s-1) to (b1-s-9).

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having a hydroxy group include those represented by any of the following formulas (b1-s-10) to (b1-s-18). .

Examples of the sulfonate anion in which Y is a cyclic ketone group include those represented by any of the following formulas (b1-s-19) to (b1-s-29).

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having an aromatic group include those represented by any of the following formulas (b1-s-30) to (b1-s-35). It is done.

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). .

Y may be an alkyl group. Examples of such a sulfonate anion include those represented by the following formula (b1-s-42).

Examples of the organic cation (Z ⁺ ) in the acid generator (B1) include organic onium cations such as organic sulfonium cation, organic iodonium cation, organic ammonium cation, benzothiazolium cation, and organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and more preferably any of the following formulas (b2-1), (b2-2), (b2-3), and (b2-4) It is an organic cation represented by

In formula (b2-1) to formula (b2-4),
R ^b4 , R ^b5 and R ^b6 each independently represent a hydrocarbon group having 1 to 30 carbon atoms, and this hydrocarbon group is an alkyl group having 1 to 30 carbon atoms or an alicyclic group having 3 to 18 carbon atoms. A hydrocarbon group 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 a saturated cyclic carbonization having 3 to 18 carbon atoms. You may have a hydrogen 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. When m2 is 2 or more, the plurality of R ^b7 are the same or different, and when n2 is 2 or more, the plurality of R ^b8 are the same or different.

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, or R ^b9 and R ^b10 are a sulfur atom to which they are bonded. Together with each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring). The methylene group contained in the ring may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.
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 when the aliphatic hydrocarbon group is an alkyl group, the number of carbon atoms is preferably 1 to 12, and the aliphatic hydrocarbon When the group is an alicyclic hydrocarbon group, the number of carbon atoms is preferably 3-18, and more preferably 4-12.
R ^b12 represents a hydrocarbon group having 1 to 18 carbon atoms, and among these hydrocarbon groups, the aromatic hydrocarbon group includes an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and a carbon number. It may have a 3-18 alicyclic hydrocarbon group or an alkylcarbonyloxy group having 1-12 carbon atoms.
R ^b11 and R ^b12 may form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) together with —CH—CO— to which they are bonded, and a methylene group constituting the ring May be replaced by 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. When p2 is 2 or more, the plurality of R ^b14 are the same or different. When s2 is 2 or more, the plurality of R ^b15 are the same. Or, when t2 is 2 or more, the plurality of R ^b18 are the same or different.

  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, and a tert-butylcarbonyloxy group. Pentylcarbonyloxy group, hexylcarbonyloxy group, octylcarbonyloxy group, 2-ethylhexylcarbonyloxy group and the like.

The aliphatic hydrocarbon group is preferably, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group. And 2-ethylhexyl group.
The alicyclic hydrocarbon group is preferably a cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyladamantan-2-yl group, 1- (adamantane-1), for example. -Yl) alkane-1-yl group and isobornyl group.
The aromatic hydrocarbon group is preferably, for example, phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, biphenylyl. Groups and naphthyl groups.
The aromatic hydrocarbon group having an aliphatic hydrocarbon group is typically an aralkyl group, and specific examples include a benzyl group.
Examples of the ring formed by combining the combination of R ^b9 and R ^b10 include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. Etc.
Examples of the ring formed by combining the combination of R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  Specific examples of the organic cation represented by the formulas (b2-1) to (b2-4) include those described in JP2010-204646A.

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す。 Among the exemplified organic cations, the cation (b2-1) is preferable, and the organic cation represented by the following formula (b2-1-1) [hereinafter referred to as “cation (b2-1-1)”] is more preferable. , Triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0), diphenyltolylsulfonium cation (in formula (b2-1-1), v2 = w2 = 0, x2 = 1 and R ^b21 is a methyl group) or tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 1, and R ^b19 , R ^b20 and R ^b21 are any Is also a methyl group).

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 preferably has 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms and an alicyclic hydrocarbon group having 4 to 18 carbon atoms. As a substituent, you may have a halogen atom, a hydroxy group, a C1-C12 alkoxy group, a C6-C18 aromatic hydrocarbon group, a C2-C4 acyl group, or a glycidyloxy group. .
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1).
When v2 is 2 or more, a plurality of R ^b19 may be the same or different. When w2 is 2 or more, a plurality of R ^b20 may be the same or different. When x2 is 2 or more, a plurality of R ^{b19 b21} may be the same or different.
Among them, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. It is.

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

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

  The acid generator (B1) is a combination of a sulfonate anion and an organic cation. A sulfonate anion and an organic cation can be arbitrarily combined. Table 1 shows combinations of sulfonate anions and organic cations. In Table 1, 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- The organic cation represented by 1) is represented as “(b2-c-1)” or the like according to the formula number.

  More preferred acid generator (B1) is one represented by any of the following 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) Or what is represented by a formula (B1-14) is more preferable. Moreover, what is represented by Formula (B1-2), Formula (B1-3), (B1-6), Formula (B1-7), or Formula (B1-11) 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).

［式（ｄ）中、ｎｄは１〜３の整数を表す。］ <Solvent (hereinafter referred to as “solvent (D)” in some cases)>
The solvent (D) contains a cyclic ketone solvent (D1). As the cyclic ketone solvent (D1), a solvent containing a 5- to 7-membered cyclic ketone structure in the molecule is preferable, and a solvent represented by the formula (d) is more preferable.

[In the formula (d), nd represents an integer of 1 to 3. ]

Examples of the 5-membered cyclic ketone solvent include cyclopentanone, 2-methyl-2-cyclopenten-1-one, 2-methylcyclopentanone, 3-methylcyclopentanone, 2-ethylcyclopentanone, 3 -Ethylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone and the like.
Examples of 6-membered cyclic ketone solvents include cyclohexanone, 2-cyclohexen-1-one, 2-methylcyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2,6-dimethylcyclohexanone, 2 , 2-dimethylcyclohexanone and the like.
Examples of the 7-membered cyclic ketone solvent include cycloheptanone and 2-cycloheptan-1-one. A polycyclic ketone solvent having a norbornane skeleton or a norbornene skeleton can also be used.
In terms of improving the dissolution stability and line edge roughness (LER) of the resist composition, cyclopentanone, cyclohexanone, and cycloheptanone are preferable, and cyclohexanone is more preferable.

  The solvent (D) preferably further contains a solvent other than the cyclic ketone solvent (D1) (hereinafter sometimes referred to as “solvent (D2)”).

The solvent (D2) is preferably at least one solvent selected from glycol ether ester solvents, glycol ether solvents, ester solvents, ketone solvents and cyclic ester solvents.
The glycol ether ester solvent is a solvent having an oxy group and a carbonyloxy group in the molecule. For example, ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate 3-methoxybutyl acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoester Examples include ethyl ether acetate and diethylene glycol monobutyl ether acetate.
The glycol ether solvent is a solvent having an oxy group in the molecule and not having a carbonyloxy group, such as propylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether and diethylene glycol monobutyl ether. It is done.
The ester solvent is a solvent having a carbonyloxy group in the molecule and not having an oxy group, such as ethyl lactate, butyl acetate, amyl acetate, ethyl acetate, isopropyl acetate, propyl acetate and ethyl pyruvate. Can be mentioned.
The ketone solvent is a solvent having a carbonyl group in the molecule and not having a carbonyloxy group (excluding a cyclic ketone solvent), such as acetone, methyl isobutyl ketone, diisobutyl ketone, and 2-heptanone. Is mentioned.
The cyclic ester solvent is a solvent having a lactone structure in the molecule, and examples thereof include γ-butyrolactone.
Among them, the solvent (D2) is preferably at least one selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and γ-butyrolactone.
These may contain only 1 type and may contain 2 or more types.

  The content of the cyclic ketone solvent (D1) is preferably 1% by mass or more and more preferably 3% by mass or more with respect to the total mass of the solvent (D). Moreover, it is preferable that it is 50 mass% or less, and it is more preferable that it is 30 mass% or less. When the content of the cyclic ketone solvent (D1) is within this range, the resist pattern produced from the resist composition has a better line edge roughness (LER), and the amount of defects in the resist pattern. Can be reduced. Further, when the content ratio of the cyclic ketone solvent (D1) is within this range, there is an effect that the etching resistance of a resist pattern produced from the resist composition is improved, and the resin contained in the resist composition There is also an effect that the solubility of the resin (AA), the resin (AB) or the like and the acid generator (B) in the solvent (D) is improved.

When the glycol ether ester solvent is included, the content is preferably 30 to 99% by mass, and more preferably 50 to 95% by mass with respect to the total mass of the solvent (D).
The content of the glycol ether solvent is preferably 1 to 70% by mass, more preferably 3 to 50% by mass, based on the total mass of the solvent (D).
When the ester solvent is included, the content is preferably 1 to 40% by mass, and more preferably 1 to 30% by mass with respect to the total mass of the solvent (D).
When the ketone solvent is included, the content thereof is preferably 1 to 40% by mass, and more preferably 3 to 30% by mass with respect to the total mass of the solvent (D).
When the cyclic ester solvent is included, the content thereof is preferably 0.1 to 30% by mass, and more preferably 0.3 to 20% by mass with respect to the total mass of the solvent (D).
When the content of the solvent is within this range, the resist pattern produced from the resist composition tends to have excellent line edge roughness (LER) and etching resistance and a small amount of defect generation. Further, since the solubility of the components contained in the resist composition in the solvent is increased, the development residue and CD uniformity tend to be improved.

  The solvent (D) has a good coating property when the resist composition is applied on a substrate in the production of a resist pattern, which will be described later, depending on the type and amount of the resin and acid generator used. Therefore, the optimum one can be selected as appropriate.

<Basic compound (C)>
The resist composition preferably contains a basic compound (C) in addition to the resin, the acid generator (B) and the solvent (D).
The basic compound (C) 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 (B).

［式（Ｃ１）中、
Ｒ^c1、Ｒ^c2及び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。］ The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and basic ammonium salts. As the amine, either an aliphatic amine or an aromatic amine may be used. 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.

[In the formula (C1),
R ^c1 , R ^c2 and R ^c3 are each independently 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 the aromatic hydrocarbon group The hydrogen atom contained is 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. It may be. ]

［式（Ｃ１−１）中、
Ｒ^c2及びＲ^c3は、前記と同義である。
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は同一でも異なっていてもよい。］

[In the formula (C1-1),
R ^c2 and R ^c3 are as defined above.
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, a plurality of R ^{c4 s} may be the same or different. ]

［式（Ｃ２）、式（Ｃ３）及び式（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、同一でも異なっていてもよい。］

[In Formula (C2), Formula (C3) and Formula (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 may be the same or different. ]

  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は同一でも異なっていてもよく、ｐ３が２以上であるとき、複数のＲ^c15は同一でも異なっていてもよい。
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 may be the same or different. When p3 is 2 or more, the plurality of R ^c15 is It may be the same or 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は同一でも異なっていてもよく、ｒ３が２以上であるとき、複数のＲ^c19は同一でも異なっていてもよく、ｓ３が２以上であるとき、複数のＲ^c20は同一でも異なっていてもよい。
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 represents an integer of 0 to 3, and when q3 is 2 or more, a plurality of R ^c18 may be the same or different. When r3 is 2 or more, a plurality of Rc18 ^c19 may be the same or different, and when s3 is 2 or more, a plurality of ^Rc20 may be 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.

<Other ingredients>
This resist composition may contain components other than the components described above as necessary. This component may be referred to as “component (F)”. Component (F) is an additive widely used in this technical field, and examples thereof include a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, and a dye.

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

The content ratio of the solvent (D) can be appropriately adjusted according to the type of the resin and the like, but is preferably 90% by mass or more, more preferably 92% by mass or more, further preferably, based on the total mass of the resist composition. Is 94% by mass or more, preferably 99% by mass or less, and more preferably 99.9% by mass or less. In addition, in this resist composition whose content of a solvent (D) is 90 mass%, content of solid content with respect to this resist composition total mass corresponds to 10 mass%. In the present specification, the “solid content” means a solvent obtained by removing the solvent from the resist composition. The solid content can be measured by a known analysis means such as liquid chromatography and gas chromatography.
This 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, for example, in a method for producing a resist pattern described later.

The resin content in the resist composition is preferably 80% by mass or more and 99% by mass or less based on the total mass of the solid content of the resist composition.
In the present resist composition, for example, as a resin,
(I) Resin (AA) only
(Ii) a combination of resin (AA) and resin (X),
(Iii) Combination of resin (AA) and resin (AB) (iv) Combination of resin (AB) and resin (X),
(V) A combination of resin (AA), resin (AB), and resin (X) may be included.

The resin in the resist composition is
(I) When it is only resin (AA), the content is preferably 80% by mass or more and 99% by mass or less with respect to the solid content of the resist composition.

(Ii) In the case of a combination of the resin (AA) and the resin (X), the total content is preferably 80% by mass or more and 99% by mass or less with respect to the solid content of the resist composition.
The mixing mass ratio of the resin (AA) and the resin (X) is preferably 0.1 to 100 parts by mass and more preferably 1 to 50 parts by mass with respect to 10 parts by mass of the resin (X). preferable.

  (Iii) In the case of a combination of the resin (AA) and the resin (AB), the content of the resin (AB) is preferably 0.1% by mass or more and 10% by mass or less with respect to the solid content of the resist composition. The content of the resin (AA) is preferably 80% by mass or more and 98.9% by mass or less based on the solid content of the resist composition.

(Iv) When the combination of the resin (AB) and the resin (X) is used, the content of the resin (AB) is preferably 0.1 to 10% by mass with respect to the solid content of the resist composition. The content of X) is preferably 80% by mass or more and 98.9% by mass or less.
The mixing mass ratio of the resin (AB) and the resin (X) is preferably 0.01 to 2 parts by mass, preferably 0.1 to 1 part by mass with respect to 10 parts by mass of the resin (X). Is more preferable.

  (V) In the case of a combination of the resin (AA), the resin (AB), and the resin (X), the content of the resin (AB) is 0.1% by mass or more and 10% by mass with respect to the solid content of the resist composition. The total content of the resin (AA) and the resin (X) is preferably 80% by mass or more and 98.9% by mass or less with respect to the solid content of the resist composition.

  The mixing mass ratio of the resin (AB) and the resin (X) is preferably 0.01 to 2 parts by mass, and 0.1 to 1 part by mass with respect to 10 parts by mass of the resin (X). More preferred.

  The content of the acid generator (B) is preferably 1 part by mass or more, more preferably 3 parts by mass or more, preferably 30 parts by mass or less, more preferably 100 parts by mass of the resin. 25 parts by mass or less.

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

  The content and content ratio of these components can be controlled by the amount used in preparing the resist composition, respectively. After preparing the resist composition, the resist composition is prepared by, for example, gas chromatography, It can be obtained by using a known analysis means such as liquid chromatography.

  In addition, when using a component (F) for this resist composition, suitable content can also be adjusted according to the kind of component (F).

<Method for producing resist pattern>
Then, the manufacturing method of the resist pattern using this resist composition is demonstrated.
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.

  The application of the resist composition onto the substrate can be performed by a coating apparatus such as a spin coater that is widely used for applying a resist material for semiconductor microfabrication. Thus, 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 (coating conditions) of the coating apparatus, and by applying an appropriate preliminary experiment, the coating film can be applied to have a desired film thickness. You can choose the conditions. Various substrates to be subjected to microfabrication can be selected as the substrate before applying the resist composition. Note that the substrate may be washed or an antireflection film may be formed before applying the resist composition. For example, a commercially available composition for an organic antireflection film can be used for forming the antireflection film.

Drying is performed, for example, by evaporating the solvent from the coating film by heating means using a heating device such as a hot plate (so-called pre-baking), decompressing means using a decompressing device, or a combination of these means. The conditions of the heating means and the decompression means are adjusted according to the type of the solvent (D) contained in the resist composition. For example, in the heating means using a hot plate (hot plate heating), the surface temperature of the hot plate May be in the range of about 50 to 200 ° C. Further, in the decompression means, after the substrate on which the coating film is formed is sealed in an appropriate decompressor, the internal pressure of the decompressor may be set to about 1 to 1.0 × 10 ⁵ Pa. Thereby, a composition layer is formed on the substrate.

In this step, the obtained composition layer is exposed. Preferably, the composition layer is exposed using an exposure machine. At this time, exposure is performed through a mask corresponding to a desired pattern to be finely processed. 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 lasers such as semiconductor lasers, etc., which convert wavelength of laser light to emit harmonic laser light in the far ultraviolet region or vacuum ultraviolet region, those which irradiate electron beams or extreme ultraviolet light (EUV), etc. Can be used. The exposure machine may be an immersion exposure machine.
As described above, by exposing through a mask, an exposed portion (exposed portion) and an unexposed portion (unexposed portion) are generated in the composition layer. In the composition layer of the exposed portion, the acid generator (B) contained in the composition layer receives exposure energy to generate an acid, and further, by the action with the generated acid, resin (AA) [or resin (X) ] Causes a deprotection reaction, and as a result, the resin (AA) [or resin (X)] in the composition layer of the exposed area becomes soluble in an aqueous alkaline solution. On the other hand, since the exposure energy is not received in the unexposed area, the resin (AA) [or resin (X)] remains insoluble or hardly soluble in the alkaline aqueous solution. Thus, the composition layer in the exposed portion and the composition layer in the unexposed portion are significantly different in solubility in the alkaline aqueous solution.

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

The composition layer after heating is developed. Preferably, the heated composition layer is developed with a developing device. The development here means that the composition layer in the exposed area is dissolved in the alkaline aqueous solution by bringing the composition layer after heating into contact with the alkaline aqueous solution, and the composition layer in the unexposed area remains on the substrate. means. Thereby, a resist pattern can be manufactured on a board | substrate.
The alkaline aqueous solution used here is referred to as “alkaline developer”, and those used in this technical field 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).

  After the development, a rinsing process is preferably performed with ultrapure water or the like, and moisture remaining on the substrate and the resist pattern is removed.

<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 immersion exposure It is suitable as a resist composition.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The composition ratio of the resin (aa) (copolymerization ratio of the structural unit derived from each monomer used in the production of the resin (aa) to the resin (aa)) is the amount of unreacted monomer in the reaction solution after the polymerization is completed. It measured using the liquid chromatography, and computed by calculating | requiring the monomer amount used for superposition | polymerization from the obtained result.
The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for 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)

Resin Synthesis The compounds (monomers) used in the resin synthesis are shown below. Hereinafter, these monomers are referred to as “monomer (MA)” to “monomer (ML)” depending on the formula number.

Synthesis Example 1 [Synthesis of Resin A1]
A monomer (MF) was used as a monomer, and methyl isobutyl ketone 1.2 times the total monomer amount was added to prepare a solution. To this solution, 2.5 mol% of azobis (2,4-dimethylvaleronitrile) as an initiator was added with respect to the total amount of monomers, and these were heated at 60 ° C. 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 1.9 × 10 ^{4 in} a yield of 80%. It was. This resin A1 has the following structural units.

Synthesis Example 2 [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 10:90. 1.2 mass times of methyl isobutyl ketone was added to make a solution. To this solution, 3.5 mol% of azobis (2,4-dimethylvaleronitrile) as an initiator was added with respect to the total amount of monomers, and these were heated at 60 ° C. 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 1.9 × 10 ^{4 in} a yield of 84%. It was. This resin A2 has the following structural units. The molar ratio of each structural unit was structural unit (u−E): structural unit (u−F) = 9.9: 90.1. Note that a structural unit or the like derived from “monomer (ME)” is referred to as “structural unit (ME)” or the like depending on its formula sign, and the same notation is used in the following synthesis examples.

Synthesis Example 3 [Synthesis of Resin X1]
As a monomer, a monomer (M-I), a monomer (M-J), a monomer (MG), a monomer (M-K) and a monomer (M-C) are used, and the molar ratio (monomer (M-I)) : Monomer (M-J): monomer (MG): monomer (M-K): monomer (M-C)) were mixed so that the ratio was 30: 14: 6: 20: 30. 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 obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and the weight average molecular weight was 8.1. A × 10 ³ resin X1 (copolymer) was obtained in a yield of 65%. This resin X1 has the following structural units. The molar ratio of each structural unit is as follows: structural unit (u-I): structural unit (u-J): structural unit (u-G): structural unit (u-K): structural unit (u-C) = 20. 1: 13.3: 6.8: 23.9: 35.9.

Synthesis Example 4 [Synthesis of Resin X2]
As a monomer, a monomer (M−H), a monomer (M−J), a monomer (M−D), a monomer (M−K), and a monomer (M−C) are used, and the molar ratio (monomer (M−H)) : Monomer (M-J): monomer (MD): monomer (M-K): monomer (M-C)) were mixed so as to be 30: 14: 6: 20: 30. 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 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.2. A x10 ³ resin X2 (copolymer) was obtained in a yield of 78%. This resin X2 has the following structural units. The molar ratio of each structural unit is as follows: structural unit (uH): structural unit (uJ): structural unit (uD): structural unit (uK): structural unit (uC) = 24. 6: 13.3: 6.5: 22.4: 33.2.

Synthesis Example 5 [Synthesis of Resin X3]
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 obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.0. A × 10 ³ resin X3 (copolymer) was obtained in a yield of 75%. This resin X3 has the following structural units. The molar ratio of each structural unit is structural unit (u-B): structural unit (u-C): structural unit (u-D) = 34.7: 45.4: 19.9.

Synthesis Example 6 [Synthesis of Resin X4]
As a monomer, a monomer (M−H), a monomer (ML), a monomer (MD), a monomer (M−K), and a monomer (M−C) are used, and the molar ratio (monomer (M−H) : Monomer (ML): monomer (MD): monomer (M-K): monomer (M-C)) are mixed so as to be 30: 14: 6: 20: 30. 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 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.2. A × 10 ³ resin X4 (copolymer) was obtained in a yield of 78%. This resin X4 has the following structural units. The molar ratio of each structural unit is as follows: structural unit (uH): structural unit (uL): structural unit (uD): structural unit (uK): structural unit (uC) = 24. 4: 13.8: 6.3: 22.2: 33.3.

Synthesis Example 7 [Synthesis of Resin Z1]
Monomer (MA) and monomer (MB) are used as monomers, and mixed so that the molar ratio (monomer (MA): monomer (MB)) 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 obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 2.8. A × 10 ⁴ resin Z1 (copolymer) was obtained in a yield of 70%.
This resin Z1 has the following structural units. The molar ratio of each structural unit was structural unit (u−A): structural unit (u−B) = 80.2: 19.8.

Examples and Comparative Examples <Preparation of Resist Composition>
The components shown in Table 2 were dissolved in the following solvents in the respective parts by mass, and further filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare a resist composition. In Table 2, the resin A1 and the like are abbreviated as “A1” and the like.

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

Ｂ３：特開２００５−２２１７２１の実施例に従って合成

<Resin>
Resins obtained in Synthesis Examples 1 to 7 <Acid generator (B)>
B1: Synthesis according to the example of JP 2010-152341 A

B2: synthesized according to examples of WO2008 / 99869 and JP2010-26478

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

<Basic compound (C): quencher>
C1: 2,6-diisopropylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Solvent (D-1)>
Propylene glycol monomethyl ether acetate 265.0 parts Propylene glycol monomethyl ether 20.0 parts Cyclohexanone 20.0 parts γ-Butyrolactone 3.5 parts <Solvent (D-2)>
Propylene glycol monomethyl ether acetate 285.0 parts Propylene glycol monomethyl ether 20.0 parts γ-butyrolactone 3.5 parts

<Manufacture of resist pattern and its evaluation>
The present resist compositions of Examples 1 to 7 and the resist composition of Comparative Example 1 were subjected to line edge roughness (LER) evaluation by immersion exposure as follows. Moreover, the defect evaluation of this resist composition of Examples 1-7 and the resist composition of Comparative Example 1 was also performed. Hereinafter, the resist composition and the resist composition of Comparative Example 1 may be collectively referred to as “resist composition”.

<Evaluation of line edge roughness (LER) after immersion exposure of resist composition>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a thickness of 78 nm. An organic antireflection film was formed. Next, the above resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (pre-baking) was 85 nm.
The obtained silicon wafer was pre-baked (PB) for 60 seconds on a direct hot plate at the temperature described in the “PB” column of Table 2. Using the ArF excimer stepper for immersion exposure [XT: 1900Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light] on the wafer on which the resist composition film is formed in this manner, the exposure amount is stepwise. The line and space pattern was subjected to immersion exposure. Note that ultrapure water was used as the immersion medium.
After the exposure, post exposure bake (PEB) is performed on the hot plate at the temperature described in the “PEB” column of Table 2 for 60 seconds, and further with a 2.38 mass% tetramethylammonium hydroxide aqueous solution for 60 seconds. Paddle development was performed to obtain a resist pattern.

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

  The wall surface of the resist pattern after the lithography process was observed with a scanning electron microscope, and the width of unevenness on the side wall of the resist pattern was measured. The results are shown in Table 3.

<Defect evaluation>
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 layer was formed on the wafer by pre-baking (PB) for 60 seconds at a temperature shown in the PB column of Table 3 on a direct hot plate.
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 3.

  In this resist composition (Examples 1 to 9), a resist pattern having excellent line edge roughness could be produced. On the other hand, in the resist compositions of Comparative Examples 1 and 2, the line edge roughness of the resulting resist pattern was poor. Moreover, the resist pattern obtained using this resist composition (Examples 1 to 9) was good in that the number of defects generated was small as compared with the resist compositions of Comparative Examples 1 and 2.

  The resist composition of the present invention can be used for fine processing of semiconductors.

Claims (11)

(A) a resin having a structural unit represented by the formula (aa),
A resist composition containing (B) an acid generator and (D1) a cyclic ketone solvent.

[In the formula (aa)
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.
A ^aa1 is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a formula (a-1)

(In the formula (a-1),
s represents an integer of 0 or 1.
X ¹⁰ and X ¹¹ each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁰ , A ¹¹ and A ¹² each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. )
Represents a group represented by ]   The resist composition according to claim 1, wherein (D1) is a 5- to 7-membered cyclic ketone solvent. The resist composition according to claim 1, wherein (D1) is a solvent represented by the following formula (d).

[In the formula (d), nd represents an integer of 1 to 3. ]   Furthermore, the resist composition in any one of Claims 1-3 containing the at least 1 sort (s) of solvent chosen from a glycol ether ester solvent, a glycol ether solvent, an ester solvent, a ketone solvent, and a cyclic ester solvent. The resist composition according to claim 1, wherein R ^{aa2 in the} formula (aa) is an aliphatic hydrocarbon group having a fluorine atom. 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.   The resist composition according to claim 1, wherein (A) is a resin that is insoluble or hardly soluble in an aqueous alkali solution and becomes soluble in an aqueous alkali solution by the action of an acid. The resist composition according to claim 1, wherein (B) is an acid generator represented by the following 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. ]   The resist composition according to claim 9, wherein Y in the formula (B1) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. (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: