JP2013178508A - Resin, resist composition and method for producing resist pattern - Google Patents

Abstract

［式（Ｉ）中、Ｒ^１は、フッ素原子を含む炭素数１〜６のアルキル基を表す。］

［式（ＩＩ）中、Ｚ１^＋は、有機カチオンを表す。］
【選択図】なしA resist composition capable of easily obtaining a resist pattern with excellent resolution is provided.
A resin (E) containing a structural unit having a group represented by the formula (I) and a structural unit having a group represented by the formula (II), an acid labile group, Resin (A) whose solubility in an alkaline aqueous solution is increased by the action of an acid, and an acid generator (B). The content of the resin (E) is about 100 parts by mass of the resin (A). A resist composition that is 5 parts by mass or more and 30% by mass or less.

[In formula (I), ^{R 1} represents an alkyl group having 1 to 6 carbon atoms containing a fluorine atom. ]

[In the formula (II), Z1 ⁺ represents an organic cation. ]
[Selection figure] None

Description

  The present invention relates to a resin, a resist composition, and a method for producing a resist pattern.

（式中、Ｒは水素原子、炭素数１〜４のアルキル基、炭素数１〜４のペルフルオロアルキル基を示し、Ｑ¹およびＱ²は２価の連結基を表す。Ｚ¹、Ｚ²、Ｚ³およびＺ⁴は、互いに独立にフッ素原子または炭素数１〜４のペルフルオロアルキル基を示す。Ａ¹⁺およびＡ²⁺は、互いに独立に、有機対イオンを表す。Ｕは水素原子、炭素数１〜４のアルキル基、あるいは、酸素原子または窒素原子を含む１価の極性基を示し、ｍは０〜２の整数を表す。） As a semiconductor microfabrication technique, an optical lithography technique using a resist composition has been studied. Patent Document 1 describes a resist composition containing a resin having a structural unit represented by the following formula (Ia) or the following formula (Ib) as a resist composition applicable to photolithography.

(In the formula, R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a perfluoroalkyl group having 1 to 4 carbon atoms, and Q ¹ and Q ² represent a divalent linking group. Z ¹ , Z ² , Z ³ and Z ⁴ each independently represent a fluorine atom or a C 1-4 perfluoroalkyl group, A ¹⁺ and A ²⁺ each independently represent an organic counter ion, U represents a hydrogen atom, carbon An alkyl group of 1 to 4 or a monovalent polar group containing an oxygen atom or a nitrogen atom, and m represents an integer of 0 to 2)

JP 2007-197718 A

The objective of this invention is providing the resist composition which can obtain the resist pattern excellent in the resolution easily.

［式（Ｉ）中、Ｒ^１は、フッ素原子を含む炭素数１〜６のアルキル基を表す。］

［式（ＩＩ）中、Ｒ^２及びＲ^３は、互いに独立に、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。
Ｚ１^＋は、有機カチオンを表す。］
［２］ 式（Ｉ）で表される基を有する構造単位は、式（Ｉ−１）で表される構造単位である［１］記載のレジスト組成物。

［式（Ｉ−１）中、
Ｒ^１ｘは、フッ素原子を含む炭素数１〜６のアルキル基を表す。
Ｒ^４は、水素原子又はメチル基を表す。
Ｘ^１は、２価の炭素数１〜１０の飽和炭化水素基を表す。］
［３］ 式（ＩＩ）で表される基を有する構造単位は、式（ＩＩ−１）で表される構造単位、又は式（ＩＩ−２）で表される構造単位である［１］又は［２］記載のレジスト組成物。

［式（ＩＩ−１）及び式（ＩＩ−２）中、
Ｒ^２Ｘ、Ｒ^３Ｘ、Ｒ^２ｙ及びＲ^３ｙは、互いに独立に、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。
Ｒ^６及びＲ^７は、互いに独立に、水素原子又はメチル基を表す。
Ｘ^２及びＸ^３は、互いに独立に、２価の連結基を表す。
Ｚ２^＋及びＺ３^＋は、有機スルホニウムカチオン又は有機ヨードニウムカチオンを表す。］
［４］式（ＩＩ）で表される基を有する構造単位は、式（ＩＩ−３）で表される構造単位である［１］〜［３］のいずれか１項に記載のレジスト組成物。

［式中、Ｒ^１３は、水素原子又はメチル基を表す。
ｕは、１又は２を表す。
Ｒ^１４は、炭素数１〜１２の飽和炭化水素基を表す。
Ｘ^１５は、炭素数１〜６のアルカンジイル基を表す。
Ｚ４^＋は、有機スルホニウムカチオン又は有機ヨードニウムカチオンを表す。］
［５］ さらにクエンチャーを含有する［１］〜［４］のいずれか１項に記載のレジスト組成物。
［６］（１）［１］〜［５］のいずれか１項に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）組成物層に露光機を用いて露光する工程、
（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。
［７］ 式（Ｉ）

［式中、Ｒ^１は、フッ素原子を含む炭素数１〜６のアルキル基を表す。］
で表される基を有する構造単位と、
式（ＩＩ−１）

［式中、
Ｒ^２ｘ及びＲ^３ｘは、互いに独立に、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。
Ｒ^６は、水素原子又はメチル基を表す。
Ｘ^２は、２価の連結基を表す。
Ｚ２^＋は、有機スルホニウムカチオン又は有機ヨードニウムカチオンを表す。］
で表される構造単位とを含む樹脂。
［８］ 式（Ｉ）で表される基を有する構造単位は、式（Ｉ−１）で表される構造単位である［７］記載の樹脂。

［式（Ｉ−１）中、
Ｒ^１Xは、フッ素原子を含む炭素数１〜６のアルキル基を表す。
Ｒ^４は、水素原子又はメチル基を表す。
Ｘ^１は、２価の炭素数１〜１０の飽和炭化水素基を表す。］ The present invention includes the following inventions.
[1] A resin (E) comprising a structural unit having a group represented by formula (I) and a structural unit having a group represented by formula (II);
A resin (A) having an acid labile group and having increased solubility in an alkaline aqueous solution by the action of the acid;
An acid generator (B),
Content of the said resin (E) is a resist composition which is 5 to 30 mass% per 100 mass parts of said resin (A).

[In formula (I), ^{R 1} represents an alkyl group having 1 to 6 carbon atoms containing a fluorine atom. ]

[In Formula (II), R ² and R ³ each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
Z1 ⁺ represents an organic cation. ]
[2] The resist composition according to [1], wherein the structural unit having a group represented by the formula (I) is a structural unit represented by the formula (I-1).

[In the formula (I-1),
R ^1x represents a C 1-6 alkyl group containing a fluorine atom.
R ⁴ represents a hydrogen atom or a methyl group.
X ¹ represents a divalent saturated hydrocarbon group having 1 to 10 carbon atoms. ]
[3] The structural unit having a group represented by the formula (II) is a structural unit represented by the formula (II-1) or a structural unit represented by the formula (II-2) [1] or [2] The resist composition according to [2].

[In Formula (II-1) and Formula (II-2),
R ^2X , R ^3X , R ^2y and R ^3y each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
R ⁶ and R ⁷ each independently represent a hydrogen atom or a methyl group.
X ² and X ³ each independently represent a divalent linking group.
Z2 ⁺ and Z3 ⁺ represent an organic sulfonium cation or an organic iodonium cation. ]
[4] The resist composition according to any one of [1] to [3], wherein the structural unit having a group represented by formula (II) is a structural unit represented by formula (II-3). .

[Wherein, R ¹³ represents a hydrogen atom or a methyl group.
u represents 1 or 2;
R ¹⁴ represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
X ¹⁵ represents an alkanediyl group having 1 to 6 carbon atoms.
Z4 ⁺ represents an organic sulfonium cation or an organic iodonium cation. ]
[5] The resist composition according to any one of [1] to [4], further containing a quencher.
[6] (1) A step of applying the resist composition according to any one of [1] to [5] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer using an exposure machine;
(4) a step of heating the composition layer after exposure; and
(5) a step of developing the composition layer after heating;
A method for producing a resist pattern including:
[7] Formula (I)

[Wherein, R ¹ represents a C 1-6 alkyl group containing a fluorine atom. ]
A structural unit having a group represented by:
Formula (II-1)

[Where:
R ^2x and R ^3x each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
R ⁶ represents a hydrogen atom or a methyl group.
X ² represents a divalent linking group.
Z2 ⁺ represents an organic sulfonium cation or an organic iodonium cation. ]
Resin containing the structural unit represented by these.
[8] The resin according to [7], wherein the structural unit having a group represented by the formula (I) is a structural unit represented by the formula (I-1).

[In the formula (I-1),
R ^1X represents a C 1-6 alkyl group containing a fluorine atom.
R ⁴ represents a hydrogen atom or a methyl group.
X ¹ represents a divalent saturated hydrocarbon group having 1 to 10 carbon atoms. ]

  According to the resist composition of the present invention, a high-resolution resist pattern can be easily produced.

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

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

  In the present specification, the “hydrocarbon group” includes an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a combination thereof. The aliphatic hydrocarbon group includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and a combined aliphatic hydrocarbon group.

Of the chain aliphatic hydrocarbon groups (hereinafter sometimes referred to as “chain hydrocarbon groups”), monovalent ones are, for example, alkyl groups, and examples of the alkyl groups include methyl groups (C ₁ ), ethyl groups. Group (C ₂ ), propyl group (C ₃ ), butyl group (C ₄ ), pentyl group (C ₅ ), hexyl group (C ₆ ), heptyl group (C ₇ ), octyl group (C ₈ ), decyl group (C _10), dodecyl (C _12), hexadecyl (C _14), pentadecyl (C _15), hexyl decyl group (C _16), include such heptadecyl group (C ₁₇₎ and octadecyl (C ₁₈₎ These may be linear or branched. The chain hydrocarbon group may be a chain unsaturated hydrocarbon group unless particularly limited, but is preferably a chain saturated hydrocarbon group, that is, an alkyl group. Examples of the divalent chain hydrocarbon group include an alkanediyl group in which one hydrogen atom has been removed from the alkyl group shown here.

Among the alicyclic aliphatic hydrocarbon groups (hereinafter sometimes referred to as “alicyclic hydrocarbon groups”), monovalent ones are groups in which one hydrogen atom has been removed from the alicyclic hydrocarbon. The alicyclic hydrocarbon group may be an alicyclic unsaturated hydrocarbon group, but in the present specification, an alicyclic saturated hydrocarbon group is preferable. The alicyclic hydrocarbon group may be monocyclic or polycyclic. The monocyclic alicyclic hydrocarbon is typically a cycloalkane. For example, cyclopropane (C ₃ ) represented by the formula (KA-1), cyclobutane represented by the formula (KA-2) ( C ₄ ), cyclopentane (C ₅ ) represented by the formula (KA-3), cyclohexane (C ₆ ) represented by the formula (KA-4), cycloheptane represented by the formula (KA-5) ( C ₇ ), cyclooctane (C ₈ ) represented by the formula (KA-6), cyclododecane (C ₁₂ ) represented by the formula (KA-7), and the like.

２価の脂環式炭化水素基としては、例えば、式（ＫＡ−１）〜式（ＫＡ−２２）の脂環式炭化水素から水素原子を２個取り去った基が挙げられる。 Examples of the polycyclic alicyclic hydrocarbon include bicyclo [2.2.1] heptane (hereinafter sometimes referred to as “norbornane”) represented by the formula (KA-8) (C ₇ ), formula (KA— 9) adamantane (C ₁₀ ) represented by formula (KA-10), alicyclic hydrocarbon (C ₁₀ ) represented by formula (KA- ₁₀ ), alicyclic hydrocarbon (C ₁₄ ) represented by formula (KA-11), formula The alicyclic hydrocarbon (C ₁₇ ) represented by (KA-12), the alicyclic hydrocarbon (C ₁₀ ) represented by formula (KA-13), and the alicyclic carbon represented by formula (KA-14) Hydrogen (C ₁₁ ), alicyclic hydrocarbon (C ₁₅ ) represented by formula (KA- ₁₅ ), alicyclic hydrocarbon (C ₁₂ ) represented by formula (KA-16), formula (KA-17) in shown are alicyclic hydrocarbons (C _14), alicyclic hydrocarbon (C ₁₅₎ of the formula (KA-18), represented by the formula (KA-19) Alicyclic hydrocarbons (C _17), alicyclic hydrocarbon represented by the formula _{(KA-20) (C 9} ), alicyclic hydrocarbon represented by the formula _{(KA-21) (C 8} ) and the formula And an alicyclic hydrocarbon (C ₁₀ ) represented by (KA-22).

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

In the present specification, the monovalent aromatic hydrocarbon group is, for example, an aryl group, and includes a phenyl group (C ₆ ), a naphthyl group (C ₁₀ ), an anthryl group (C ₁₄ ), a biphenyl group (C ₁₂ ), Examples thereof include a phenanthryl group (C ₁₄ ) and a fluorenyl group (C ₁₃ ). Examples of the divalent aromatic hydrocarbon group include an arylene group obtained by removing one hydrogen atom from a monovalent aromatic hydrocarbon group.

  The aliphatic hydrocarbon group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group, an acyl group, an aryl group, an aralkyl group, and an aryloxy group.

The halogen atom is a fluorine atom, a chlorine atom, a bromine atom and an iodine atom unless otherwise specified.
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 ). The alkoxy group may be linear or branched.
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 ( C ₈ ), decanoyl groups (C ₁₀ ), dodecanoyl groups (C ₁₂ ) and other alkyl groups and carbonyl groups, and benzoyl groups (C ₇ ) and other aryl groups and carbonyl groups Is mentioned. Among the acyl groups, an alkyl group and a carbonyl group bonded to each other may be linear or branched.
Examples of the aryloxy group include those in which the aryl group and an oxygen atom are bonded.
Examples of the aralkyl group include benzyl group (C ₇ ), phenethyl group (C ₈ ), phenylpropyl group (C ₉ ), naphthylmethyl group (C ₁₁ ), and naphthylethyl group (C ₁₂ ).

  The aromatic hydrocarbon group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group, an acyl group, an alkyl group, and an aryloxy group.

［式中、Ｒ^１はフッ素原子を含む炭素数１〜６のアルキル基を表す。］

［式（ＩＩ）中、Ｒ^２及びＲ^３は、互いに独立に、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。
Ｚ１^＋は、有機カチオンを表す。］
本発明のレジスト組成物において、樹脂（Ｅ）の含有量は、樹脂（Ａ）１００質量部あたり５質量部以上、３０質量％以下である。
本発明のレジスト組成物は、樹脂（Ｅ）と樹脂（Ａ）とを含有し、更に樹脂（Ｅ）の含有量が上記範囲内にあるので、解像度が高いレジストパターンを容易に製造することができる。
以下、本発明のレジスト組成物に含まれる各成分について説明する。 The resist composition of the present invention comprises:
A resin (E) comprising a structural unit having a group represented by formula (I) and a structural unit having a group represented by formula (II);
A resin (A) having an acid labile group and having increased solubility in an alkaline aqueous solution by the action of the acid;
An acid generator (B).

[Wherein, R ¹ represents a C 1-6 alkyl group containing a fluorine atom. ]

[In Formula (II), R ² and R ³ each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
Z1 ⁺ represents an organic cation. ]
In the resist composition of the present invention, the content of the resin (E) is 5 parts by mass or more and 30% by mass or less per 100 parts by mass of the resin (A).
Since the resist composition of the present invention contains the resin (E) and the resin (A) and the content of the resin (E) is within the above range, it is possible to easily produce a resist pattern with high resolution. it can.
Hereinafter, each component contained in the resist composition of the present invention will be described.

［式（Ｉ）中、Ｒ^１はフッ素原子を含む炭素数１〜６のアルキル基を表す。］

［式（ＩＩ）中、Ｒ^２及びＲ^３は、互いに独立に、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。
Ｚ１^＋は、有機カチオンを表す。］ <Resin (E)>
The resin (E) includes a structural unit having a group represented by the formula (I) and a structural unit having a group represented by the formula (II).

[In Formula (I), R ¹ represents a C 1-6 alkyl group containing a fluorine atom. ]

[In Formula (II), R ² and R ³ each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
Z1 ⁺ represents an organic cation. ]

Examples of the alkyl group containing a fluorine atom represented by R ¹ include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, and a 2,2,2-trifluoroethyl group. Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1 , 2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1, 2,2,3,3,4,4-octafluorobutyl group, 3- (trifluoromethyl) -2,2,3,4,4,4-hexafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoromethyl) -2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl Group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3 , 3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1, Examples include 2,2,3,3,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group and perfluorohexyl group.

R ¹ is preferably an alkyl group having 1 to 4 carbon atoms containing a fluorine atom, more preferably a trifluoromethyl group, a perfluoroethyl group or a perfluoropropyl group, and still more preferably a trifluoromethyl group. It is.

Examples of the structural unit having a group represented by formula (I) include a structural unit derived from a compound having a group represented by formula (I) and a polymerizable group.
Examples of the polymerizable group include a group having a carbon-carbon double bond, preferably a group having an ethylenic double bond, and more preferably a (meth) acryl group.

［式（Ｉ−１）中、
Ｒ^１ｘは、フッ素原子を含む炭素数１〜６のアルキル基を表す。
Ｒ^４は、水素原子又はメチル基を表す。
Ｘ^１は、炭素数１〜１０の２価の飽和炭化水素基を表す。］ As the structural unit having a group represented by the formula (I), a structural unit represented by the formula (I-1) is preferable.

[In the formula (I-1),
R ^1x represents a C 1-6 alkyl group containing a fluorine atom.
R ⁴ represents a hydrogen atom or a methyl group.
X ¹ represents a divalent saturated hydrocarbon group having 1 to 10 carbon atoms. ]

Examples of the alkyl group containing a fluorine atom represented by R ^1x include those exemplified as the group represented by R ¹ described above.

R ^1x is preferably an alkyl group having 1 to 4 carbon atoms containing a fluorine atom, more preferably a trifluoromethyl group, a perfluoroethyl group or a perfluoropropyl group, still more preferably a trifluoromethyl group. It is.

Examples of the divalent saturated hydrocarbon group represented by X ¹ include an alkanediyl group having 1 to 10 carbon atoms and a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms.

The X ^1, ethylene, propane-1,3-diyl, butane-1,3-diyl group, 2-methyl-1,3-diyl, 2-methylpropane-1,2-diyl group An alkanediyl group having 2 to 5 carbon atoms; adamantane ring such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,3-diyl group, adamantane-2,6-diyl group Alternatively, a group having a nobornane ring is preferable, and an alkanediyl group having 2 to 4 carbon atoms such as an ethylene group, a propane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group is more preferable.

［式（Ｉ−１’）中、各符号は前記と同義である。］ The structural unit represented by the formula (I-1) is derived from the compound represented by the formula (I-1 ′).

[In formula (I-1 ′), each symbol is as defined above. ]

Examples of the compound represented by the formula (I-1 ′) include the following compounds.

  The compound represented by the formula (I-1 ′) can be produced by the methods described in JP-A-2005-23304 and JP-A-2005-281301.

  The content of the structural unit having a group represented by the formula (I) is usually 40 to 99 mol%, more preferably 60 to 98 mol%, based on all structural units of the resin (E). More preferably, it is 80-97 mol%.

で表される基において、Ｒ^２及びＲ^３は、互いに独立に、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。
Ｒ^２及びＲ^３により表わされるペルフルオロアルキル基とは、炭素数１〜６のアルキル基に含まれる水素原子の全部がフッ素原子に置換されたものであり、例えば、ペルフルオロメチル基、ペルフルオロエチル基、ペルフルオロプロピル基、ペルフルオロイソプロピル基、ペルフルオロブチル基、ペルフルオロｓｅｃ−ブチル基、ペルフルオロｔｅｒｔ−ブチル基、ペルフルオロペンチル基及びペルフルオロヘキシル基が挙げられる。
Ｒ^２及びＲ^３は、好ましくは、互いに独立に、ペルフルオロメチル基又はフッ素原子であり、より好ましくはともにフッ素原子である。 Formula (II)

In the group represented by R ² and R ³ , each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
The perfluoroalkyl group represented by R ² and R ³ is one in which all of the hydrogen atoms contained in the alkyl group having 1 to 6 carbon atoms are substituted with fluorine atoms. For example, a perfluoromethyl group, a perfluoroethyl group, Examples include perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluoro sec-butyl group, perfluoro tert-butyl group, perfluoropentyl group and perfluorohexyl group.
R ² and R ³ are preferably each independently a perfluoromethyl group or a fluorine atom, more preferably a fluorine atom.

In the formula (II), Z1 ⁺ represents an organic cation.
Examples of the organic cation represented by Z1 ⁺ include an organic onium cation such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazonium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferable.

［各式において、Ｒ^２ｘ、Ｒ^３ｘ、Ｒ^２ｙ及びＲ^３ｙは、互いに独立に、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。
Ｒ^６及びＲ^７は、互いに独立に、水素原子又はメチル基を表す。
Ｘ^２及びＸ^３は、互いに独立に、２価の連結基を表す。
Ｚ２^＋及びＺ３^＋は、有機スルホニウムカチオン又は有機ヨードニウムカチオンを表す。］ As the structural unit having a group represented by the formula (II), a structural unit represented by the formula (II-1) and a structural unit represented by the formula (II-2) are preferable.

[In each formula, R ^2x , R ^3x , R ^2y and R ^3y each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
R ⁶ and R ⁷ each independently represent a hydrogen atom or a methyl group.
X ² and X ³ each independently represent a divalent linking group.
Z2 ⁺ and Z3 ⁺ represent an organic sulfonium cation or an organic iodonium cation. ]

Examples of the perfluoroalkyl group represented by R ^2x , R ^3x , R ^2y and R ^3y include those exemplified as the group represented by R ² and R ³ .
R ^2x , R ^3x , R ^2y and R ^3y are preferably each independently a perfluoromethyl group or a fluorine atom, more preferably a fluorine atom.

The divalent linking group represented by X ² and X ³ is preferably a divalent hydrocarbon group having 1 to 23 carbon atoms, and the methylene group contained in these hydrocarbon groups includes an oxygen atom and a sulfur atom. Or it may be replaced by a carbonyl group.
Examples of such a divalent linking group include * —CO—O—, * —O—, * —S—, * —CO—X ⁴ —, * —CO—O—X ⁴ —, * —. O—X ⁴ —, * —S—X ⁴ —, * —CO—O—X ⁴ —O—, * —CO—O—X ⁴ —S—, * —CO—O—X ⁴ —O—CO —, * —CO—O—X ⁴ —CO—O—, * —CO—O—X ⁴ —O—X ⁵ —, * —CO—O—X ⁴ —S—X ⁵ —, * —CO—. O—X ⁴ —CO—O—X ⁵ —, * —CO—O—X ⁴ —O—CO—X ⁵ —, * —X ⁴ —O—X ⁵ —, * —X ⁴ —S—X ^{5 -, * - X 4 -CO-} O-X 5 -, * - X 4 -O-CO-X 5 -, * - CO-O-X 4 -O-X 5 -O-X 6 -, * - CO—O—X ⁴ —S—X ⁵ —S—X ⁶ —, * —CO—O—X ⁴ —S—X ⁵ —O—X ^{6 -, * - CO-O} -X 4 -O-X 5 -S-X 6 - and ^{* -CO-O-X 4 -O} -X 5 -CO-X 6 - equal (wherein * is Represents a bond to C (R ^2x ) (R ^3x ) or C (R ^2y ) (R ^3y ), X ⁴ , X ⁵ and X ⁶ are each independently a hydrocarbon group having 1 to 12 carbon atoms; However, the total number of carbon atoms in each group represented by each formula is 23 or less, and this carbon number represents the number of carbon atoms before the methylene group is replaced with an oxygen atom, sulfur atom or carbonyl group.)
Is mentioned.
The X ^{2, preferably, * - CO-O -,} * - CO-O-X 4 -, * - CO-O-X 4 -O -, * - CO-O-X 4 -CO-O- * -CO—O—X ⁴ —O—CO—, * —X ⁴ —CO—O—X ⁵ —, * —X ⁴ —O—CO—X ⁵ —, * —CO—O—X ⁴ — O—X ⁵ —O—X ⁶ —, * —CO—O—X ⁴ —S—X ⁵ —O—X ⁶ —,
More preferably, * —CO—O—X ⁴ —, * —CO—O—X ⁴ —O—, * —CO—O—X ⁴ —O—CO—, * —CO—O—X ⁴ —S. -X ⁵ -O-X ^6- ,
More preferably, * —CO—O—X ⁴ —O—CO—, * —CO—O—X ⁴ —
It is.
X ³ is preferably * —X ⁴ —, * —CO—O—, * —CO—O—X ⁴ —, * —CO—O—X ⁴ —O—, * —CO—O—X. ⁴ -CO—O—, * —CO—O—X ⁴ —CO—O—X ⁵ —, * —X ⁴ —CO—O—X ⁵ —, * —CO—O—X ⁴ —O—X ⁵ -CO-X ^6-
More ^{preferably, * - X 4 -, *} - CO-O-X 4 -, * - CO-O-X 4 -CO-O-X 5 -, * - X 4 -CO-O-X 5 -, * —CO—O—X ⁴ —O—X ⁵ —CO—X ⁶ —,
More ^{preferably, * - X 4 -, *} - CO-O-X 4 - , and the like.
As the hydrocarbon group represented by X ⁴ , X ⁵ and X ⁶ , an alkanediyl group (specifically an alkanediyl group having 1 to 12 carbon atoms, preferably an alkanediyl group having 1 to 4 carbon atoms), divalent Alicyclic hydrocarbon group (specifically, carbon such as a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, preferably adamantane-1,3-diyl group, adamantane-2,6-diyl group, etc. A divalent alicyclic hydrocarbon group having 6 to 10 carbon atoms), a divalent aromatic hydrocarbon group (specifically, a divalent aromatic hydrocarbon group having 3 to 12 carbon atoms, preferably 1,4- A divalent aromatic hydrocarbon group having 6 to 10 carbon atoms such as a benzene group and a 1,4-naphthalene group), a group in which the alkanediyl group and the divalent alicyclic hydrocarbon group are combined. .

Examples of the anion contained in the structural unit represented by the formula (II-1) include the following structural units and the structural units described in JP2011-158896A.

式（ＩＩ−２）により表わされる構造単位として、さらに式（ＩＩ−３）で表される構造単位が挙げられる。

［式中、Ｒ^１３は、水素原子又はメチル基を表す。
ｕは、１又は２を表す。
Ｒ^１４は、炭素数１〜１２の飽和炭化水素基を表す。
Ｘ^１５は、炭素数１〜６のアルカンジイル基を表す。
Ｚ４^＋は、有機スルホニウムカチオン又は有機ヨードニウムカチオンを表す。］ Examples of the anion of the structural unit represented by the formula (II-2) include the following structural units, as well as JP2011-76084 A, JP2011-190246 A, 2011-219459, and JP2007. -197718 and the structural unit of Unexamined-Japanese-Patent No. 2006-178317 are mentioned.

Examples of the structural unit represented by the formula (II-2) further include a structural unit represented by the formula (II-3).

[Wherein, R ¹³ represents a hydrogen atom or a methyl group.
u represents 1 or 2;
R ¹⁴ represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
X ¹⁵ represents an alkanediyl group having 1 to 6 carbon atoms.
Z4 ⁺ represents an organic sulfonium cation or an organic iodonium cation. ]

Examples of the saturated hydrocarbon group represented by R ¹⁴ include an alkyl group having 1 to 12 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms.
The R ^14, preferably a cycloalkyl group of the alkyl group and 3 to 8 carbon atoms having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms.
X ¹⁵ is preferably a methylene group or an ethylene group.

Examples of the structural unit represented by the formula (I-3) include the following structural units and the structural units described in WO2012 / 050015.

Examples of the cation represented by Z2 ⁺ , Z3 ⁺ and Z4 ⁺ include a cation represented by any one of formulas (b2-1) to (b2-4).

[In Formula (b2-1)-Formula (b2-4),
R ^b4 , R ^b5 and R ^b6 each independently represent a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent.
R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.
R ^b9 and R ^b10 each independently represent an alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, 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 ^b12 represents an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The aromatic hydrocarbon group is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkylcarbonyloxy group having 1 to 12 carbon atoms. May be substituted.
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 contained in the ring May be replaced by an oxygen atom, a sulfur atom or a carbonyl group.
^{R b13, R b14, R b15} , R b16, R b17 and R ^b18 are each independently a hydroxy group, an alkyl group or an alkoxy group having 1 to 12 carbon atoms having 1 to 12 carbon atoms.
L ^b11 represents an oxygen atom or a sulfur atom.
o2, p2, s2, and t2 each independently represent 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 may be the same or different. When p2 is 2 or more, the plurality of R ^b14 may be the same or different. When s2 is 2 or more, the plurality of R ^b15 is ^They may be the same or different, and when t2 is 2 or more, the plurality of R ^b18 may be the same or different. ]

The hydrocarbon group represented by R ^b4 , R ^b5 and R ^b6 is preferably independently of each other an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or 6 to 6 carbon atoms. 18 is an aromatic hydrocarbon group, and the hydrogen atom contained in the alkyl group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and the aromatic hydrocarbon group includes a halogen atom, hydroxy Group, a C1-C18 alkyl group, a C3-C18 saturated cyclic hydrocarbon group, or a C1-C12 alkoxy group may be substituted.

Examples of the alkylcarbonyloxy group represented by R ^b12 include methylcarbonyloxy group, ethylcarbonyloxy group, n-propylcarbonyloxy group, isopropylcarbonyloxy group, n-butylcarbonyloxy group, sec-butylcarbonyloxy group, tert- Examples thereof include a butylcarbonyloxy group, a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

^Examples of the alkyl group represented by R ^b9 , R ^b10 , R ^b11 and R ^b12 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group. , A hexyl group, an octyl group, a 2-ethylhexyl group, and the like are preferable.
Examples of the alicyclic hydrocarbon group represented by R ^b9 , R ^b10 and R ^b11 include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclodecyl group, a 2-alkyladamantan-2-yl group, A 1- (adamantan-1-yl) alkane-1-yl group and an isobornyl group are preferred.
^Examples of the aromatic hydrocarbon group represented by R ^b12 include phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, Biphenylyl group, naphthyl group and the like are preferable.
A ^combination of an aromatic hydrocarbon group represented by R ^b12 and an alkyl group is typically an aralkyl group.
Examples of the ring formed by combining R ^b9 and R ^b10 include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. It is done.
^Examples of the ring formed by combining R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  As a cation represented by Formula (b2-1)-Formula (b2-4), what was described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example.

［式（ｂ２−１−１）中、
Ｒ^b19、Ｒ^b20及びＲ^b21は、互いに独立に、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、置換基を有していてもよい炭素数１〜１８の脂肪族炭化水素基又は炭素数１〜１２のアルコキシ基を表す。
ｖ２、ｗ２及びｘ２は、互いに独立に０〜５の整数（好ましくは０又は１）を表す。
ｖ２が２以上のとき、複数のＲ^b19は互いに同一でも異なってもよく、ｗ２が２以上のとき、複数のＲ^b20は互いに同一でも異なってもよく、ｘ２が２以上のとき、複数のＲ^b21は互いに同一でも異なってもよい。］ Among the cations represented by formula (b2-1) to formula (b2-4), the cation represented by formula (b2-1) and the cation represented by formula (b2-2) are preferable, and the formula (b2 -1) is more preferable, and a cation represented by formula (b2-1-1) is more preferable. As a cation represented by the formula (b2-1-1), a triphenylsulfonium cation (in the formula (b2-1-1), v2 = w2 = x2 = 0) or a tolylsulfonium cation (formula ( In b2-1-1), v2 = w2 = x2 = 1 and R ^b19 , R ^b20 and R ^b21 are all methyl groups.

[In the formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 are independently of each other a halogen atom (more preferably a fluorine atom), a hydroxy group, an ^optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms or a carbon number. 1 to 12 alkoxy groups are represented.
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, and 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 as or different from each other. ]

The aliphatic hydrocarbon group represented by R ^b19 , R ^b20 and R ^b21 is preferably an aliphatic hydrocarbon group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms or 4 to 4 carbon atoms. 18 alicyclic hydrocarbon groups. Examples of the substituent that the aliphatic hydrocarbon group may have include a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, and 2 to 4 carbon atoms. An acyl group and a glycidyloxy group are mentioned.
R ^b19 , R ^b20 and R ^b21 are preferably independently of each other 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. .

  Examples of the structural unit represented by the formula (II) include combinations of the above-mentioned anions and the above-mentioned organic cations. These can be arbitrarily combined, and examples thereof include the following structural units.

Content of the structural unit containing group represented by Formula (II) is 1-25 mol% normally with respect to all the structural units of resin (E), More preferably, it is 2-20 mol%, More Preferably it is 3-15 mol%.
The resin (E) may have only one type or two or more types of the structural unit containing the group represented by the formula (I) and the structural unit containing the group represented by the formula (II). These monomers can be produced by a known polymerization method (for example, radical polymerization method) using monomers that lead to the structural unit. The content rate of each structural unit can be adjusted with the usage-amount of the monomer used when manufacturing resin (E).

Among the resins (E), a resin containing a structural unit having a group represented by the above formula (I) and a structural unit represented by the above formula (II-1) has been newly found. This resin is one of the present inventions.
Specific examples and preferred ranges of the respective structural units in the resin of the present invention are the same as those described in the description relating to the resin (E).

<Resin (A)>
The resin (A) has an acid labile group (hereinafter sometimes referred to as “acid labile group”), and has a property of increasing the solubility in an aqueous alkaline solution by the action of the acid (hereinafter referred to as “ It has an acid action characteristic ”). Note that “the solubility in an alkaline aqueous solution is increased by the action of an acid” means that the solubility in an alkaline aqueous solution is increased by contact with an acid. It is preferably insoluble or hardly soluble in an aqueous alkali solution before contact with an acid, and soluble in an aqueous alkali solution after contact with an acid.
Resin (A) differs from resin (E) in that it does not have a group represented by formula (II).

  Resin (A) has an acid labile group. That is, the resin (A) has a structural unit derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”).

［式（１）中、Ｒ^a1、Ｒ^a2及びＲ^a3は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜２０の脂環式炭化水素基を表すか、Ｒ^a1及びＲ^a2は互いに結合して炭素数２〜２０の２価の炭化水素基を形成し、Ｒ^a3は炭素数１〜８のアルキル基又は炭素数３〜２０の脂環式炭化水素基を表す。＊は結合手を表す。］ <Structural unit having acid instability>
“Acid labile group” means a group that has a leaving group and forms a hydrophilic group (for example, a hydroxy group or a carboxy group) by leaving the leaving group upon contact with an acid.
Examples of the acid labile group include a group represented by the formula (1) (hereinafter sometimes referred to as “acid labile group (1)”) and a group represented by the formula (2) (hereinafter referred to as “acid-unstable group”). Stable group (2) ”).

Wherein (1), R ^a1, R ^a2 and R ^a3 each independently represent a cycloaliphatic hydrocarbon radical of the alkyl group or 3 to 20 carbon atoms having 1 to 8 carbon atoms, R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and R ^a3 represents an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms. * Represents a bond. ]

［式（２）中、Ｒ^ａ１’及びＲ^ａ２’は、互いに独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^ａ３’は、炭素数１〜２０の炭化水素基を表すか、Ｒ^ａ１’は、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^ａ２’及びＲ^ａ３’は互いに結合して炭素数２〜２０の２価の炭化水素基を形成し、該炭化水素基及び該２価の炭化水素基に含まれるメチレン基は、酸素原子又は硫黄原子で置き換わってもよい。＊は結合手を表す。］

[In the formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. R ^{a1 ′} represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms. The methylene group contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced with an oxygen atom or a sulfur atom. * Represents a bond. ]

The alicyclic hydrocarbon group represented by R ^a1 , R ^a2 and R ^a3 preferably has 3 to 16 carbon atoms.

Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group include the following groups. The divalent hydrocarbon group preferably has 3 to 12 carbon atoms.

Examples of the acid labile group (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and R ^a3 are alkyl groups, preferably a tert-butoxycarbonyl group). , 2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 and R ^a2 combine to form an adamantyl group and R ^a3 is an alkyl group) and 1- (adamantane-1 -Yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups and R ^a3 is an adamantyl group) and the like.

Examples of the hydrocarbon group of R ^{a1 ′} and R ^{a2 ′} of the acid labile group (2) include an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

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

The monomer (a1) is preferably a monomer having an acid labile group and a carbon-carbon double bond, and more preferably a monomer having an acid labile group and a (meth) acryl group.
The monomer (a1) is preferably a monomer (a1) having an acid labile group (1) and / or an acid labile group (2), and the acid labile group (1) and / or the acid labile group (2) A (meth) acrylic monomer having s is particularly preferred.
The monomer (a1) is preferably a monomer (a1) having an alicyclic hydrocarbon group having 5 to 20 carbon atoms. Since the resin (A) obtained using such a monomer (a1) has an alicyclic hydrocarbon group having a bulky structure, it is obtained from the resist composition of the present invention containing the resin (A). The resolution of the resist pattern tends to be higher.

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、互いに独立に、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−を表し、ｋ１は１〜７の整数を表し、＊はカルボニル基との結合手を表す。
Ｒ^a4及びＲ^a5は、互いに独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、互いに独立に、炭素数１〜１０の脂肪族炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ１’は０〜３の整数を表す。］ The structural unit derived from the monomer (a1) is represented by the structural unit represented by the formula (a1-1) (hereinafter sometimes referred to as “structural unit (a1-1)”) and the formula (a1-2). The structural unit (hereinafter sometimes referred to as “structural unit (a1-2)”) is preferred, and the structural unit (a1-1) is more preferred.

[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, and * represents a bond to a carbonyl group. Represent.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an aliphatic hydrocarbon group having 1 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

^K1 in ^* —O— (CH ₂ ) _k1 —CO—O— of L ^a1 and L ^a2 is preferably an integer of 1 to 4, and more preferably 1. L ^a1 and L ^a2 are preferably oxygen atoms.
R ^a4 and R ^a5 are preferably methyl groups.
The aliphatic hydrocarbon group for R ^a6 and R ^a7 is preferably an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms. The alkyl group preferably has 8 or less carbon atoms, more preferably 6 or less carbon atoms. The alicyclic hydrocarbon group preferably has 8 or less carbon atoms, more preferably 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 structural unit (a1-1), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. A structural unit represented by any one of formula (a1-1-1) to formula (a1-1-8) is preferred, and represented by any one of formulas (a1-1-1) to (a1-1-4). More preferred is a structural unit.

  Examples of the monomer (a1) that leads to the structural unit (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethylcycloheptane. Examples include -1-yl (meth) acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, and 1-isopropylcyclopentan-1-yl (meth) acrylate.

The structural unit (a1-2) is preferably a structural unit represented by any one of the formulas (a1-2-1) to (a1-2-6)], more preferably the formula ( a structural unit (a1-2) represented by a1-2-3) or (a1-2-4), more preferably a structural unit represented by the formula (a1-2-3).

In the resin (A), the content of the structural unit derived from the monomer (a1) is preferably from 10 to 95 mol%, more preferably from 15 to 90 mol%, based on the total structural units of the resin (A). -85 mol% is more preferable, and 20-60 mol% is especially preferable.
When resin (A) has a structural unit (a1-1) and / or a structural unit (a1-2), it is preferable that these total content rates are in said range.
The structural unit (a1) preferably has a structural unit (a1) having an adamantyl group (particularly preferably, the structural unit (a1-1)). In this case, the content of the structural unit (a1) having an adamantyl group is preferably 15 mol% or more with respect to the total of the structural units (a1). When the resin (A) has a structural unit (a1) having an adamantyl group at such a content, the dry etching resistance of the resist pattern produced from the resist composition containing the resin (A) is good. Tend to be.

式（ａ１−３）中、
Ｒ^a9は、水素原子、置換基（例えばヒドロキシ基）を有していてもよい炭素数１〜３の脂肪族炭化水素基、カルボキシ基、シアノ基、又は−ＣＯＯＲ^a13で表される基を表し、Ｒ^a13は、炭素数１〜８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等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。
Ｒ^a10、Ｒ^a11及びＲ^a12は、互いに独立に、炭素数１〜１２の脂肪族炭化水素基を表すか、Ｒ^a10及びＲ^a11は互いに結合してこれらが結合する炭素原子とともに環を形成し、Ｒ^a12は、炭素数１〜１２の脂肪族炭化水素基を表す。該脂肪族炭化水素基及に含まれる水素原子はヒドロキシ基等で置換されていてもよく、該脂肪族炭化水素基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。 Examples of the monomer (a1) further include a monomer represented by the formula (a1-3) (hereinafter sometimes referred to as “monomer (a1-3)”). When a resin (A) obtained from such a monomer and containing a rigid norbornane ring in the main chain is used for the resist composition of the present invention, a resist pattern having excellent dry etching resistance tends to be produced.

In formula (a1-3),
R ^a9 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a substituent (for example, a hydroxy group), a carboxy group, a cyano group, or a group represented by —COOR ^a13. , R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, constituting the aliphatic hydrocarbon group The methylene group may be replaced by an oxygen atom or a carbonyl group.
R ^a10 , R ^a11 and R ^a12 each independently represent an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or R ^a10 and R ^a11 are bonded to each other to form a ring together with the carbon atom to which they are bonded. , R ^a12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.

Examples of the aliphatic hydrocarbon group represented by R ^a9 , R ^a10 , R ^a11 and R ^a12 include an alkyl group. Examples of the substituent, particularly the aliphatic hydrocarbon group having a hydroxy group, include a hydroxymethyl group and a 2-hydroxyethyl group.
^Examples of R ^a13 include a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, and a 2-oxo-oxolan-4-yl group.

Examples of the ring and R ^a10 and R ^a11 are formed with bonded carbon atoms to which they are attached, hexane ring and adamantane ring, and the like cyclohexylene.

As the monomer (a1-3), for example, those described in JP 2010-204646 A are used. Among these, the monomers (a1-3-1), (a1-3-3), (a1-3-3) and (a1-3-4) represented by the following formulas (a1-3-1), 3) is preferred, the monomer (a1-3) represented by formula (a1-3-2) or (a1-3-4) is more preferred, and the monomer (a1 represented by formula (a1-3-2)) -3) is more preferable.

  When the resin (A) has a structural unit derived from the monomer (a1-3), the content is preferably 10 to 95 mol% with respect to the total structural unit of the resin (A), and is preferably 15 to 90 mol. % Is more preferable, and 20 to 85 mol% is more preferable.

式（ａ１−４）中、
Ｒ¹⁰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^ａは０〜４の整数を表す。
Ｒ¹¹は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表し、ｌ^ａが２以上である場合、複数のＲ¹¹は互いに同一であっても異なってもよい。
Ｒ¹²及びＲ¹³は、互いに独立に、水素原子又は炭素数１〜１２の炭化水素基を表す。
Ｘ^a2は、置換基を有していてもよい炭素数１〜１７の脂肪族炭化水素基又は単結合を表し、該脂肪族炭化水素基に含まれるメチレン基は、酸素原子、硫黄原子、カルボニル基、スルホニル基又は−Ｎ（Ｒ^ｃ）−（ただし、Ｒ^ｃは、水素原子又は炭素数１〜６のアルキル基を表す）で置き換わっていてもよい。
Ｙ^a3は、置換基を有していてもよい炭素数１〜１８の炭化水素基を表す。 Examples of the monomer (a1) further include a monomer represented by the formula (a1-4) (hereinafter sometimes referred to as “monomer (a1-4)”).

In formula (a1-4),
R ¹⁰ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
l ^a represents an integer of 0 to 4;
R ¹¹ is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or It represents a methacryloyloxy group, when l ^a is 2 or more, plural R ¹¹ may be the same or different from each other.
R ¹² and R ¹³ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
X ^a2 represents an ^optionally substituted aliphatic hydrocarbon group having 1 to 17 carbon atoms or a single bond, and the methylene group contained in the aliphatic hydrocarbon group includes an oxygen atom, a sulfur atom, a carbonyl A group, a sulfonyl group, or —N (R ^c ) — (wherein R ^c represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms).
Y ^a3 represents an ^optionally substituted hydrocarbon group having 1 to 18 carbon atoms.

Represented by R ^10, The halogen atom may have an alkyl group having 1 to 6 carbon atoms, a fluorine atom is preferable. Examples of the alkyl group having a fluorine atom include the same groups as those in R ¹ of the formula (I-1).
R ¹⁰ 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.
The alkoxy group represented by R ¹¹ 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.
Examples of the hydrocarbon group for R ¹² , R ¹³ and Y ^a3 include an aliphatic hydrocarbon group and an aromatic hydrocarbon group.
Examples of the aliphatic hydrocarbon group represented by X ^a2 include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, and a divalent group in which these are combined.

As a monomer (a1-4), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Among them, the following formula (a1-4-1), formula (a1-4-2), formula (a1-4-3), formula (a1-4-4), formula (a1-4-5), formula Monomers respectively represented by (a1-4-6) and formula (a1-4-7) [formula (a1-4-1) to formula (a1-4-7)] are preferred, and the formula (a1-4 -1) to monomers represented by formula (a1-4-5) are more preferable.

  When the resin (A) has a structural unit derived from the monomer (a1-4), the content thereof is preferably 10 to 95 mol% with respect to all the structural units of the resin (A), and 15 to 90 mol%. Is more preferable, and 20-85 mol% is further more preferable.

式（ａ１−５）中、
Ｒ^a8は、水素原子又はメチル基を表す。
Ａ^１は、単結合、酸素原子又はカルボニル基を表す。
Ａ^２は炭素数１〜６のアルカンジイル基を表す。
Ｒ^a1、Ｒ^a2及びＲ^a3は、前記と同義である。 As the structural unit derived from the monomer (a1), a structural unit (a1) derived from the monomer represented by the formula (a1-5) (hereinafter sometimes referred to as “monomer (a1-5)”) is further included. Can be mentioned.

In formula (a1-5),
R ^a8 represents a hydrogen atom or a methyl group.
A ¹ represents a single bond, an oxygen atom or a carbonyl group.
A ² represents an alkanediyl group having 1 to 6 carbon atoms.
R ^a1 , R ^a2 and R ^a3 are as defined above.

R ^a1 , R ^a2 and R ^a3 in the structural unit (a1-5) are each independently a methyl group, ethyl group, propyl group, butyl group, heptyl group and hexyl group, or R ² and R ³ are It is preferable that they are bonded to form a ring having 3 to 12 carbon atoms together with the carbon atom to which they are bonded. The ring is preferably an adamantane ring or a cyclohexane ring.

As a structural unit (a1-5), the following structural units are mentioned, for example. In the formula, R ^a8 represents a hydrogen atom or a methyl group.

  When the resin (A) has the structural unit (a1-5), the content is preferably from 3 to 80 mol%, more preferably from 5 to 70 mol%, based on all the structural units of the resin (A). 5 to 60 mol% is more preferable.

<Acid stable structural unit>
The resin (A) preferably has a structural unit having no acid labile group (hereinafter sometimes referred to as “acid-stable structural unit”) together with the structural unit derived from the monomer (a1). The acid stable structural unit is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “acid stable monomer”).

  When the resin (A) has an acid stable structural unit, the content ratio of the structural unit derived from the monomer (a1) to the acid stable structural unit ([structural unit derived from the monomer (a1)] / [acid stable structural unit] ]: The molar ratio is preferably 10/90 to 80/20, more preferably 20/80 to 60/40. When the content ratio is such, the dry etching resistance of the resist pattern obtained from the resist composition of the present invention tends to be further improved.

  The acid stable structural unit includes an acid stable structural unit having a hydroxy group (hereinafter sometimes referred to as “acid stable structural unit (a2)”) and an acid stable structural unit having a lactone ring (hereinafter referred to as “acid stable structural unit ( a3) ”))). When the resin (A) having these structural units is used, the film and / or composition layer obtained by applying the resist composition of the present invention to the substrate tends to be excellent in adhesion to the substrate. A pattern can be manufactured.

<Acid stable structural unit (a2)>
The acid stable structural unit (a2) can be selected depending on the type of exposure source used when producing a resist pattern from the resist composition of the present invention. For example, when the exposure source is a KrF excimer laser (wavelength: 248 nm), a high energy beam such as an electron beam or EUV light, the acid stable structural unit (a2) is an acid having a phenolic hydroxy group described later. Stable structural unit (a2-0) is preferred. When the exposure source is an ArF excimer laser (wavelength: 193 nm), the acid stable structural unit (a2) is preferably an acid stable structural unit represented by the formula (a2-1).

式（ａ２−１）中、
Ｌ^a3は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−（ｋ２は１〜７の整数を表し、＊はカルボニル基（−ＣＯ−）との結合手を表す。）で表される基を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、互いに独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。 Examples of the acid stable structural unit (a2) include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as “acid stable structural unit (a2-1)”).

In formula (a2-1),
L ^a3 is an oxygen atom or ^* —O— (CH ₂ ) _k2 —CO—O— (k2 represents an integer of 1 to 7, and * represents a bond to a carbonyl group (—CO—)). Represents the group represented.
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.

L ^a3 is preferably an oxygen atom or a group represented by —O— (CH ₂ ) _k2 —CO—O—, wherein k2 is an integer of 1 to 4, more preferably an oxygen atom or — O—CH ₂ —CO—O—, 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 structural unit (a2-1) include structural units derived from the monomers described in the following and JP-A No. 2010-204646.

  Among these, the acid stable structural unit represented by any one of formula (a2-1-1), formula (a2-1-2), formula (a2-1-3) and formula (a2-1-4) The acid stable structural unit represented by the formula (a2-1-1) or (a2-1-3) is more preferable.

  When the resin (A) has an acid stable structural unit (a2-1), the content is preferably 1 to 45 mol%, more preferably 2 to 35 mol%, based on all structural units of the resin (A). Preferably, 3 to 30 mol% is more preferable.

式（ａ２−０）中、
Ｒ^a30は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^a31は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^a31は同一でも異なっていてもよい。 Examples of the acid stable structural unit (a2) include a structural unit represented by the formula (a2-0) (hereinafter sometimes referred to as “acid stable structural unit (a2-0)”).

In formula (a2-0),
R ^a30 represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
R ^a31 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
ma represents an integer of 0 to 4. When ma is an integer of 2 or more, the plurality of R ^a31 may be the same or different.

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.
R ^a31 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and still more preferably 0.

The acid stable structural unit (a2-0) is represented by formula (a2-0-1), formula (a2-0-2), formula (a2-0-3) or formula (a2-0-4). Those are preferred. Examples of the acid-stable monomer for deriving such a structural unit include monomers described in JP2010-204634A.

  Resin (A) containing an acid stable structural unit (a2-0) is a protective group capable of detaching the phenolic hydroxy group in the monomer (a2) leading to the acid stable structural unit (a2-0) with an acid or a base. Can be prepared by preliminarily protecting and polymerizing with, and then removing the protecting group with an acid or a base. The deprotection is preferably performed with a base so as not to significantly damage the structural unit (a1). Examples of the protecting group include an acetyl group.

  When the resin (A) has an acid stable structural unit (a2-0), the content is preferably from 5 to 90 mol%, more preferably from 10 to 85 mol%, based on all structural units of the resin (A). Preferably, 15 to 80 mol% is more preferable.

<Acid stable structural unit (a3)>
The lactone ring included in the acid stable structural unit (a3) may be monocyclic such as β-propiolactone ring, γ-butyrolactone ring and δ-valerolactone ring, and the monocyclic lactone ring and other rings 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）中、
Ｌ^a4は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^a18は、水素原子又はメチル基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a21は炭素数１〜４の脂肪族炭化水素基を表し、ｐ１が２以上の場合、複数のＲ^a21は互いに同一でも異なってもよい。
式（ａ３−２）中、
Ｌ^a5は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
ｑ１は、０〜３の整数を表す。
Ｒ^a22は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表し、ｑ１が２以上の場合、複数のＲ^a22は互いに同一でも異なってもよい。
式（ａ３−３）中、
Ｌ^a6は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^a20は、水素原子又はメチル基を表す。
ｒ１は、０〜３の整数を表す。
Ｒ^a23は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表し、ｒ１が２以上の場合、複数のＲ^a23は互いに同一でも異なってもよい。］ The acid stable structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3).

[In the formula (a3-1),
L ^a4 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
p1 represents an integer of 0 to 5.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and when p1 is 2 or more, a plurality of R ^a21 may be the same as or different from each other.
In formula (a3-2),
L ^a5 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
q1 represents an integer of 0 to 3.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and when q1 is 2 or more, the plurality of R ^a22 may be the same or different from each other.
In formula (a3-3),
L ^a6 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
r1 represents an integer of 0 to 3.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. When r1 is 2 or more, a plurality of R ^{a23 s} may be the same as or different from each other. ]

In Formula (a3-1) to Formula (a3-3), L ^a4 , L ^a5, and L ^a6 are the same as those described for L ^a3 in Formula (a2-1).
L ^a4 , L ^a5 and L ^a6 are each independently an oxygen atom or a group represented by * —O— (CH ₂ ) _k3 —CO—O—, wherein k3 is an integer of 1 to 4, An atom and * —O—CH ₂ —CO—O— are more preferable, and an oxygen atom is more preferable.
R ^a18 , R ^a19 , R ^a20 and R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are independently of each other preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are preferably integers of 0 to 2, more preferably 0 or 1.

Examples of the structural unit represented by the formula (a3-1), the formula (a3-2), or the formula (a3-3) include a structural unit derived from an acid stable monomer described in JP2010-204646A. It is done.
The structural unit represented by formula (a3-1) is represented by formula (a3-1-1), formula (a3-1-2), formula (a3-1-3), or formula (a3-1-4). The structural unit represented is preferred.

The structural unit represented by formula (a3-2) is represented by the following formula (a3-2-1), formula (a3-2-2), formula (a3-2-3), or formula (a3-2-4). ) Is preferred.

The structural unit represented by formula (a3-3) is represented by the following formula (a3-3-1), formula (a3-3-2), formula (a3-3-3), or formula (a3-3-4). ) Is preferred.

  In particular, the acid stable structural unit (a3) is preferably a structural unit represented by the formula (a3-1) or a structural unit represented by the formula (a3-2), and the formula (a3-1-1) to the formula ( The structural unit represented by a3-1-2) or formula (a3-2-3) to formula (a3-2-4) is more preferred, and formula (a3-1-1) or formula (a3-2-3) ) Is more preferred.

  When the resin (A) has an acid stable structural unit (a3), the content is preferably from 5 to 70 mol%, more preferably from 10 to 65 mol%, based on all structural units of the resin (A). 10 to 60 mol% is more preferable.

<Other acid stable structural units>
The resin (A) may have other acid-stable structural units other than the above (hereinafter sometimes referred to as “acid-stable structural units (a4)”).
Examples of the acid-stable monomer that leads to the acid-stable structural unit (a4) include styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, isoisoboronyl acrylate, tricyclodecanyl (meta ) Acrylate, tetracyclododecenyl (meth) acrylate, and the like, and preferably styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, and 3-methylstyrene.

  When the resin (A) has such an acid-stable structural unit (a4), the content is preferably 1 to 50 mol%, and 2 to 40 mol% with respect to all the structural units of the resin (A). Is more preferable, and 3-30 mol% is further more preferable.

<Method for producing resin (A)>
Each structural unit constituting the resin (A) may have only one type or two or more types, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. be able to. The content rate of each structural unit can be adjusted with the usage-amount of the monomer used when manufacturing resin (A).
The resin (A) is preferably a copolymer of a monomer (a1) and an acid-stable monomer, and more preferably a monomer and / or structural unit (a1-2) that leads to the structural unit (a1-1). It is a copolymer of a monomer (a1) that leads to a monomer that leads to an acid stable structural unit (a2) and / or an acid stable monomer that leads to an acid stable structural unit (a3).

When the specific example of resin (A) is shown by the combination of a structural unit, resin represented by a formula (A-1)-a formula (A-21) will be mentioned, for example.

  The weight average molecular weight of the resin (A) is preferably 2,500 or more and 50,000 or less, and more preferably 3,000 or more and 30,000 or less. In addition, the weight average molecular weight here is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography. Detailed analysis conditions for this analysis are described in the Examples of the present application.

<Acid generator (B)>
The acid generator (B) is classified into a nonionic type and an ionic type, and any of them may be used.
Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonate) and sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like.
Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) and the like. 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, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712 The compound which generate | occur | produces an acid by the radiation as described in etc. can be used.

［式（Ｂ１）中、
Ｑ^１及びＱ^２は、互いに独立に、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。］ The acid generator (B) is preferably a fluorine-containing acid generator, more preferably an acid comprising a compound containing a group represented by the formula (B1) and having an anion containing a hydrocarbon group or a hydroxyl group at the terminal. Generator). Examples of such an acid generator include salts described in JP 2010-204646 A.

[In the formula (B1),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group. ]

［式（Ｂ１−１）中、
Ｑ^１及びＱ^２は、互いに独立に、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。
Ｙ^１は、２価の炭素数６〜１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれるメチレン基は、酸素原子、スルホニル基又はカルボニル基で置き換わってもよい。
Ｙ^２は、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、フッ素原子または水素原子を表し、該脂肪族炭化水素基に含まれるメチレン基は、酸素原子、スルホニル基又はカルボニル基で置き換わってもよい。
Ｌ^１は、単結合又は炭素数１〜１７の２価の直鎖または分岐鎖の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子で置換されてもよく、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基で置き換わってもよい。
Ｌ^２は、単結合又は炭素数１〜１７の２価の直鎖または分岐鎖の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基で置き換わってもよい。
ｎは、０又は１を表す。
Ｚ⁺は、有機カチオンを表す。］ As the acid generator (B), a salt containing a group represented by the formula (B1) and having an anion having 17 or more carbon atoms is preferable, and a salt represented by the formula (B1-1) is more preferable.

[In the formula (B1-1),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
Y ¹ represents a divalent alicyclic hydrocarbon group having 6 to 18 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group.
Y ² represents an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, a fluorine atom or a hydrogen atom, and the methylene group contained in the aliphatic hydrocarbon group includes an oxygen atom, A sulfonyl group or a carbonyl group may be substituted.
L ¹ represents a single bond or a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, The methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
L ² represents a single bond or a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. Good.
n represents 0 or 1.
Z ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group of Q ¹ and Q ² include the same groups as R ² and R ³ in the above formula (II), and are preferably a trifluoromethyl group or a fluorine atom independently of each other, and more preferably Are both fluorine atoms.

The alicyclic hydrocarbon group represented by Y ¹ is preferably a group represented by any one of formulas (Y1) to (Y7). * Represents a bond.

Examples of the group in which the methylene group contained in the alicyclic hydrocarbon group represented by Y ¹ is replaced by an oxygen atom, a sulfonyl group, or a carbonyl group include groups represented by formula (Y8) to formula (Y20). Is mentioned.

Y ¹ is preferably a group represented by any one of formulas (Y1) to (Y16), more preferably represented by formula (Y7), formula (Y8), formula (Y10) or formula (Y14). And more preferably a group represented by formula (Y7) or formula (Y14).

Examples of the alicyclic hydrocarbon group represented by Y ² include groups represented by formulas (Y21) to (Y31).

Examples of the group in which the methylene group contained in the alicyclic hydrocarbon group represented by Y ² is replaced by an oxygen atom, a sulfonyl group, or a carbonyl group include groups represented by formula (Y32) to formula (Y46). Is mentioned.

Y ² is preferably a group represented by any one of formulas (Y21) to (Y39), more preferably formula (Y23), formula (Y24), formula (Y31), formula (Y34), formula A group represented by formula (Y35) or formula (Y39), more preferably a group represented by formula (Y24), formula (Y31) or formula (Y34), particularly preferably formula (Y24) or formula (Y34). It is a group represented by (Y31).

Examples of the substituent that the alicyclic hydrocarbon group represented by Y ² may have include a halogen atom, a hydroxy group, and an alkyl group having 1 to 12 carbon atoms that may have a hydroxy group, C3-C16 alicyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 aromatic hydrocarbon group, C7-C21 aralkyl group, C2-C4 acyl Group, glycidyloxy group, — (CH ₂ ) _j2 —O—CO—R ^b1 (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or carbon. Represents an aromatic hydrocarbon group having a number of 6 to 18. j2 represents an integer of 0 to 4), —CO—O—R ^b2 —O—R ^b3 (wherein R ^b2 represents 1 to 4 carbon atoms). And R ^b3 represents an alkyl group having 1 to 4 carbon atoms).
In the alkyl group which is a substituent of the alicyclic hydrocarbon group, the hydrogen atom may be substituted with an alkoxy group having 1 to 6 carbon atoms or a fluorine atom, and is a substituent of the alicyclic hydrocarbon group. In the alicyclic hydrocarbon group, aromatic hydrocarbon group and aralkyl group, the hydrogen atom may be substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or a fluorine atom.

The halogen atom may be any of those already exemplified.
Examples of the alkyl group having a hydroxy group include a hydroxymethyl group and a hydroxyethyl group.

Among the alicyclic hydrocarbon group represented by Y ^2, Examples of the group having a substituent group, include groups represented by the formula (Y47) ~ formula (Y56).

Y ² preferably represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the methylene group contained in the alicyclic hydrocarbon group includes an oxygen atom and a sulfonyl group. Or a carbonyl group may be substituted, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxy group or an aromatic hydrocarbon group, and a hydrogen atom contained in the aromatic hydrocarbon group May be substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a fluorine atom.
Y ² is more preferably an adamantyl group which may have a substituent. In this case, examples of the substituent include an alkyl group having 1 to 6 carbon atoms, a hydroxy group, and an aromatic group having 6 to 18 carbon atoms. A hydrocarbon group is mentioned. When n = 1, an adamantyl group having an unsubstituted or alkyl group having 1 to 6 carbon atoms is more preferable, and when n = 0, an adamantyl group having an aromatic hydrocarbon group having 6 to 18 carbon atoms is more preferable.

式（ｂ１−１）〜式（ｂ１−６）中、
Ｌ^b2は、単結合又は炭素数１〜１５のアルカンジイル基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２のアルカンジイル基を表す。
Ｌ^b4は、炭素数１〜１３のアルカンジイル基を表す。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、単結合又は、炭素数１〜１５のアルカンジイル基を表す。
Ｌ^b6及びＬ^b7は、互いに独立に、炭素数１〜１５のアルカンジイル基を表す。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のアルキレン基を表す。
Ｌ^b9及びＬ^b10は、互いに独立に、炭素数１〜１１のアルカンジイル基を表す。但しＬ^b9及びＬ^b10の合計炭素数の上限は１２である。
Ｌ^１は、式（ｂ１−１）で表される基が好ましく、Ｌ^b2が単結合又はメチレン基である式（ｂ１−１）で表される基がより好ましい。 The saturated hydrocarbon group represented by L ¹ is preferably a linear or branched saturated hydrocarbon group.
The methylene group contained in the saturated hydrocarbon group represented by L ¹ is substituted with an oxygen atom or a carbonyl group, for example, represented by any one of formula (b1-1) to formula (b1-6). Group. In formula (b1-1) ~ formula (b1-6), combines the left and right have been described in accordance with the formula (B1-1), on the left side C (Q ¹⁾ and (Q ^2), right To Y ¹ (or Y ² ).

In formula (b1-1) to formula (b1-6),
L ^b2 represents a single bond or an alkanediyl group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms.
L ^b4 represents an alkanediyl group having 1 to 13 carbon atoms. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a single bond or an alkanediyl group having 1 to 15 carbon atoms.
L ^b6 and L ^b7 each independently represent an alkanediyl group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents an alkylene group having 1 to 14 carbon atoms.
L ^b9 and L ^b10 each independently represent an alkanediyl group having 1 to 11 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12.
L ¹ is preferably a group represented by the formula (b1-1), more preferably a group represented by the formula (b1-1) in which L ^b2 is a single bond or a methylene group.

The saturated hydrocarbon group for L ¹ is a linear or branched saturated hydrocarbon group, and a group in which the methylene group is replaced with an oxygen atom or a carbonyl group is preferable.
Examples of the group in which the methylene group contained in the saturated hydrocarbon group of L ² is replaced with an oxygen atom or a carbonyl group include the same groups as those of L ¹ .
L ² is preferably a group represented by the formula (b1-1) or a group represented by the formula (b1-5), and L ^b2 is represented by the formula (b1-1) in which a single bond or a methylene group is represented. The group represented by the formula (b1-5) in which the group or L ^b8 is a methylene group is more preferable.

Examples of the anion of the salt represented by the formula (B1-1) include an anion represented by any one of the formula (b1-1-1) to the formula (b1-1-14), and JP2011-46694A. And sulfonic acid anions described in JP-A-2008-74843. In the formula, L ¹ , L ^b2 and L ^b8 are as defined above, and are preferably groups represented by the formula (b1-1) or the formula (b1-5). R ^b1 and R ^b2 represent an alkyl group having 1 to 4 carbon atoms, preferably a methyl group.

Examples of Z ^{+ in} formula (B1-1) include the same organic cations as Z1 ⁺ , Z2 ⁺ and Z3 ⁺ in formula (II). Preferably, formula (b2-1) to formula (b2- It is a cation represented by any one of 4).

The salt represented by the formula (B1-1) is a combination of the above anion and the above organic cation. These can be arbitrarily combined, and a preferable combination is, for example, a salt represented by the following formula.

<Quencher (C)>
The resist composition of the present invention may further contain a quencher.
The quencher in the resist composition of the present invention may be any compound that has an acid diffusion suppressing action, that is, a compound that traps an acid generated from an acid generator upon exposure. In addition to this action, the quencher generates an acid itself. It may be a compound obtained. Examples include basic nitrogen-containing organic compounds and weak acid salts.
Examples of basic nitrogen-containing organic compounds include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.
Examples of the amine include compounds represented by any one of the formulas (C1) to (C8), and a compound represented by the formula (C1-1) is preferable.

［式（Ｃ１）中、
Ｒ^c1、Ｒ^c2及びＲ^c3は、互いに独立に、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。］

[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、互いに同一でも異なってもよい。］

[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 as or different from each other. ]

［式（Ｃ２）、式（Ｃ３）及び式（Ｃ４）中、
Ｒ^c5、Ｒ^c6、Ｒ^c7及びＲ^c8は、互いに独立に、Ｒ^c1と同義である。
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、互いに同一又は相異なる。］
アルカノイル基としては、アセチル基、２−メチルアセチル基、２，２−ジメチルアセチル基、プロピオニル基、ブチリル基、イソブチリル基、ペンタノイル基、２，２−ジメチルプロピオニル基等が挙げられる。

[In Formula (C2), Formula (C3) and Formula (C4),
R ^c5 , R ^c6 , R ^c7 and R ^c8 are the same as R ^c1 independently of each other.
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an alkanoyl group having 2 to 6 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 are the same or different from each other. ]
Examples of the alkanoyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, and 2,2-dimethylpropionyl group.

［式（Ｃ５）及び式（Ｃ６）中、
Ｒ^c10、Ｒ^c11、Ｒ^c12、Ｒ^c13及びＲ^c16は、互いに独立に、Ｒ^c1と同義である。
Ｒ^c14、Ｒ^c15及びＲ^c17は、互いに独立に、Ｒ^c4と同義である。
ｏ３及びｐ３は、互いに独立に０〜３の整数を表し、ｏ３が２以上のとき、複数のＲ^c14は互いに同一でも異なってもよく、ｐ３が２以上のとき、複数のＲ^c15は互いに同一でも異なってもよい。
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 have the same ^meaning as R ^c1 independently of each other.
R ^c14 , R ^c15 and R ^c17 have the same ^meaning as R ^c4 independently of each other.
o3 and p3 each independently represent an integer of 0 to 3, and when o3 is 2 or more, the plurality of R ^c14 may be the same or different from each other. When p3 is 2 or more, the plurality of R ^c15 are the same as each other But it may be 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、互いに独立に、Ｒ^c4と同義である。
ｑ３、ｒ３及びｓ３は、互いに独立に０〜３の整数を表し、ｑ３が２以上のとき、複数のＲ^c18は互いに同一でも異なってもよく、ｒ３が２以上のとき、複数のＲ^c19は互いに同一でも異なってもよく、ｓ３が２以上のとき、複数のＲ^c20は互いに同一でも異なってもよい。
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 ^{c 20} are each independently the same meaning as R ^c4.
q3, r3 and s3 each independently represent an integer of 0 to 3. When q3 is 2 or more, a plurality of R ^c18 may be the same or different from each other. When r3 is 2 or more, a plurality of R ^c19 is They may be the same or different, and when s3 is 2 or more, the plurality of R ^c20 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- Examples include diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, and 4,4′-diamino-3,3′-diethyldiphenylmethane. Ropiruanirin. Particularly preferred include 2,6-diisopropylaniline.

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 Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like can be mentioned.

［式（Ｃ９）中、
Ｒ^Ｃ２１は、置換基を有していてもよい炭素数１〜１０の脂肪族炭化水素基、置換基を有してもよい炭素数４〜３６の脂環式炭化水素基、置換基を有していてもよい炭素数３〜３６の芳香族炭化水素基又は置換基を有していてもよい炭素数３〜３６の複素環基を表し、該脂肪族炭化水素基及び該脂環式炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基で置換されていてもよい。
Ｚ'^＋は、有機カチオンを表す。］ Examples of the weak acid salt include a salt of an acid weaker than the acid generated from the acid generator (B). Examples of the weak acid salt include a carboxylate and a sulfonate, and among them, a carboxylate represented by the formula (C9) and a sulfonate represented by the formula (C10) or the formula (C11) are preferable. .

[In the formula (C9),
R ^C21 has an optionally substituted aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 4 to 36 carbon atoms that may have a substituent, and a substituent. Represents an optionally substituted aromatic hydrocarbon group having 3 to 36 carbon atoms or an optionally substituted heterocyclic group having 3 to 36 carbon atoms, the aliphatic hydrocarbon group and the alicyclic carbonized group. The methylene group contained in the hydrogen group may be substituted with an oxygen atom or a carbonyl group.
Z ′ ⁺ represents an organic cation. ]

［式（Ｃ１０）中、
Ｒ^Ｃ２２及びＲ^Ｃ２３は、互いに独立に、水素原子、炭素数１〜１２の脂肪族炭化水素基、炭素数３〜２０の脂環式飽和炭化水素基、炭素数６〜２０の芳香族炭化水素基又は炭素数７〜２１のアラルキル基を表し、該脂肪族炭化水素基、該脂環式飽和炭化水素基、該芳香族炭化水素基及びアラルキル基に含まれる水素原子は、ヒドロキシル基、シアノ基、フッ素原子、トリフルオロメチル基又はニトロ基で置換されていてもよく、該脂肪族炭化水素基に含まれる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く、Ｒ^Ｃ２２及びＲ^Ｃ２３は互いに結合してこれらが結合する窒素原子とともに炭素数４〜２０の環を形成してもよい。］

［式（Ｃ１１）中、
Ｑ^ｅ1及びＱ^ｅ2は、互いに独立に、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^ｅ２は、単結合または炭素数１〜１７の２価の脂肪族飽和炭化水素基を表し、該脂肪族飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙ^Ｎは窒素原子を含む有機基を表す。
Ｚ^＋は、有機カチオンを表す。］

[In the formula (C10),
R ^C22 and R ^C23 are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or an aromatic hydrocarbon having 6 to 20 carbon atoms. A hydrogen atom contained in the aliphatic hydrocarbon group, the alicyclic saturated hydrocarbon group, the aromatic hydrocarbon group and the aralkyl group is a hydroxyl group or a cyano group. , A fluorine atom, a trifluoromethyl group or a nitro group, the methylene group contained in the aliphatic hydrocarbon group may be replaced by an oxygen atom or a carbonyl group, and R ^C22 and R ^C23 are You may combine and form a C4-C20 ring with the nitrogen atom which these couple | bond. ]

[In the formula (C11),
Q ^e1 and Q ^e2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^e2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the aliphatic saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. .
Y ^N represents an organic group containing a nitrogen atom.
Z ⁺ represents an organic cation. ]

^Examples of Q ^e1 and Q ^e2 include the same groups as Q ¹ and Q ² in formula (b1-1), and preferred examples are also the same.
Examples of the aliphatic saturated hydrocarbon group represented by L ^e2, methylene group, alkylene group having 1 to 17 carbon atoms such as ethylene group; adamantylene group, an alicyclic hydrocarbon having a carbon number of 3 to 17, such as a cyclohexylene group Group; and a group obtained by combining the alkylene group and the alicyclic hydrocarbon group.
Le ² is preferably a C 5-10 alkylene group in which a methylene group is replaced by an oxygen atom or a carbonyl group, and a group in which the alkylene group and an alicyclic hydrocarbon are combined.
Y ^N is a heterocyclic group preferably containing a nitrogen atom. Examples of the heterocyclic ring include an imidazole ring and a morpholine ring.

Examples of the organic cation of Z ⁺ include the same organic cation as Z1 ^{+ of} formula (I), preferably an organic sulfonium cation or an organic iodonium cation, and more preferably a formula (b2-1) to a formula ( a cation represented by any one of b2-4), more preferably a cation represented by formula (b2-1).

As a compound represented by a formula (C9), the following compound and the compound of Unexamined-Japanese-Patent No. 2011-39502 are mentioned, for example.

As a compound represented by a formula (C10), the following compound and the compound of Unexamined-Japanese-Patent No. 2011-191745 are mentioned, for example.

As a salt represented by a formula (C11), the salt represented by a following formula and the salt of Unexamined-Japanese-Patent No. 2012-6908 are mentioned, for example.

<Solvent (D)>
The resist composition of the present invention usually contains a solvent.
The solvent (D) is not particularly limited as long as it dissolves the components contained in the resist composition of the present invention. For example, glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate Glycol ethers such as propylene glycol monomethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; lactones such as γ-butyrolactone; And mixed solvents thereof.

<Other components (hereinafter sometimes referred to as “other components (F)”)>
The resist composition of this invention may contain the other component (F) as needed. The other component (F) is not particularly limited, and examples thereof include additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes.

<Method for producing resist composition>
The resist composition of the present invention comprises a resin (E), a resin (A), an acid generator (B), and a solvent (D), a quencher (C) and other components (F) used as necessary. ) Can be mixed. The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can be suitably selected in the range of 10-40 degreeC according to the kind etc. of resin, the solubility to a solvent (D), etc. The mixing time can be appropriately selected within the range of 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 total content of the resin in the resist composition of the present invention is preferably 80% by mass or more and 99% by mass or less with respect to the total solid content.

  Content of resin (E) in the resist composition of this invention is 5 mass parts or more and 30 mass parts or less with respect to 100 mass parts of resin (A), Preferably it is 25 mass parts or less.

  The content of the acid generator (B) is preferably 1 part by mass or more and 35 parts by mass or less, and more preferably 3 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the resin (A).

When the resist composition of the present invention contains a quencher (C), the content is preferably about 0.01 to 4% by mass relative to the total amount of solids.
In the present specification, the “solid content” means the total of components excluding the solvent (D) from the resist composition of the present invention. The mass of the solid content and the content of each component contained in the resist composition of the present invention can be measured by known analysis means such as liquid chromatography or gas chromatography.

  The content of the solvent (D) is preferably 90% by mass or more, more preferably 92% by mass or more, still more preferably 94% by mass or more, and 99.9% by mass or less, based on the total amount of the resist composition of the present invention. Is preferable, and 99.5 mass% or less is more preferable. When the content of the solvent (D) is within the above range, a composition layer having a thickness of about 30 to 300 nm can be easily formed when a resist pattern is produced.

  When using other component (F), the content is suitably selected according to the kind of other component (F).

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) The process of apply | coating the resist composition of this invention on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure and (5) a step of developing the composition layer after heating.

  The application of the resist composition of the present invention on the substrate in the step (1) can be performed by a coating apparatus such as a spin coater which is usually used in the field. Examples of the substrate include a silicon wafer. Before applying the resist composition of the present invention, the substrate may be washed or an antireflection film or the like may be formed.

In step (2), the composition after application is dried to remove the solvent and form a composition layer on the substrate. Drying is performed by, for example, heat drying using a heating device such as a hot plate (so-called pre-baking), vacuum drying using a decompression device, or a combination of these means. The temperature in this case is preferably about 50 to 200 ° C., for example. The pressure is preferably about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), electron beams, and ultra-ultraviolet light ( Use various types such as those that irradiate EUV), those that emit laser light from a solid-state laser light source (such as YAG or semiconductor laser) and radiate harmonic laser light in the far ultraviolet region or vacuum ultraviolet region. Can do. The exposure machine may be an immersion exposure machine.

Step (3) is a step of exposing the composition layer, and preferably a step of exposing the composition layer using an exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), electron beams, and ultra-ultraviolet light ( Use various types such as those that irradiate EUV), those that emit laser light from a solid-state laser light source (such as YAG or semiconductor laser) and radiate harmonic laser light in the far ultraviolet region or vacuum ultraviolet region. Can do. The exposure machine may be an immersion exposure machine. In this specification, the irradiation of these radiations may be collectively referred to as “exposure”.

  Step (4) is a step of heating the composition layer after exposure (so-called post-exposure baking), and preferably a step of developing with a heating device. An example of the heating device is a hot plate. As heating temperature, it is 50-200 degreeC normally, Preferably, it is 70-150 degreeC. The heating time is usually 20 to 90 seconds, preferably 30 to 70 seconds. By performing the step (4), the deprotection reaction of the resin (A) is promoted.

Step (5) is a step of developing the heated composition layer, and preferably a step of developing the heated composition layer with a developer using a developing device. The development method may be either positive development or negative development. As the developer, an organic solvent such as a ketone solvent, an ester solvent, an amide solvent, an ether solvent, a hydrocarbon solvent, or an alkali developer can be used.
For the development, an alkali developer is usually used. Examples of the alkaline developer include aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline).
After the development, it is preferable to perform a rinsing process with ultrapure water or the like and further remove moisture remaining on the substrate and the resist pattern.

<Application>
The resist composition of the present invention is useful as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) irradiation, or a resist composition for EUV exposure. It is. In particular, since a high-resolution resist pattern can be produced, it is useful for a resist composition for electron beams or EUV.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The weight average molecular weight of the resin is a value determined by gel permeation chromatography (HLC-8120GPC type manufactured by Tosoh Corporation). The analysis conditions of gel permeation chromatography are as follows.
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

Resin Synthesis The compounds (monomers) used for resin synthesis are shown below.

Synthesis Example 1 (Synthesis of Resin E1)
Monomer J was synthesized by the method described in JP-A-2007-197718.
A four-necked flask equipped with a condenser and a stirrer was charged with 6.30 parts of acetonitrile and heated to 60 ° C. Monomer I (manufactured by Central Glass Co., Ltd.) 20.47 parts, monomer J 4.66 parts [molar ratio; monomer I: monomer J = 90: 10] and azobis-2,4-dimethylvaleronitrile 0.488 parts were added to acetonitrile. A solution dissolved in 24.12 parts was added dropwise over 1 hour. Thereafter, stirring was continued for 5 hours while maintaining 60 ° C. The reaction solution was cooled to 40 ° C. Next, 653 parts of n-heptane was cooled to 10 ° C., and the reaction solution was poured therein to precipitate a resin. The resin collected by filtration was dissolved in 65.3 parts of tetrahydrofuran. Further, a resin dissolved in 643 parts of n-heptane cooled to 10 ° C. was poured to precipitate the resin. The precipitated resin was collected by filtration and dried under reduced pressure to obtain 23.4 parts of a resin having a weight average molecular weight of 5.2 × 10 ³ . This resin is referred to as a resin E1. This resin E1 has the following structural units.

Synthesis Example 2 (Synthesis of Resin E2)
Monomer K was synthesized by the method described in JP-A-2007-197718.
A four-necked flask equipped with a condenser and a stirrer was charged with 6.30 parts of acetonitrile and heated to 60 ° C. Monomer I (manufactured by Central Glass Co., Ltd.) 20.47 parts, monomer K 5.27 parts [molar ratio; monomer I: monomer K = 90: 10] and azobis-2,4-dimethylvaleronitrile 0.488 parts were added to acetonitrile. A solution dissolved in 24.12 parts was added dropwise over 1 hour. Thereafter, stirring was continued for 5 hours while maintaining 60 ° C. The reaction solution was cooled to 40 ° C. Next, 653 parts of n-heptane was cooled to 10 ° C., and the reaction solution was poured therein to precipitate a resin. The resin collected by filtration was dissolved in 65.3 parts of tetrahydrofuran. Further, a resin dissolved in 643 parts of n-heptane cooled to 10 ° C. was poured to precipitate the resin. The precipitated resin was collected by filtration and dried under reduced pressure to obtain 23.9 parts of a resin having a weight average molecular weight of 5.0 × 10 ³ . This resin is referred to as a resin E2. This resin E2 has the following structural units.

Synthesis Example 3 (Synthesis of Resin E3)
Monomer L was synthesized by the method described in JP 2011-76084 A.
A four-necked flask equipped with a condenser and a stirrer was charged with 6.30 parts of acetonitrile and heated to 60 ° C. Monomer I (Central Glass Co., Ltd.) 20.47 parts, monomer L 5.65 parts [molar ratio; monomer I: monomer L = 90: 10] and azobis-2,4-dimethylvaleronitrile 0.488 parts were added to acetonitrile. A solution dissolved in 24.12 parts was added dropwise over 1 hour. Thereafter, stirring was continued for 5 hours while maintaining 60 ° C. The reaction solution was cooled to 40 ° C. Next, 653 parts of n-heptane was cooled to 10 ° C., and the reaction solution was poured therein to precipitate a resin. The resin collected by filtration was dissolved in 65.3 parts of tetrahydrofuran. Further, a resin dissolved in 643 parts of n-heptane cooled to 10 ° C. was poured to precipitate the resin. The precipitated resin was collected by filtration and dried under reduced pressure to obtain 24.0 parts of a resin having a weight average molecular weight of 5.3 × 10 ³ . This resin is referred to as a resin E3. This resin E3 has the following structural units.

Synthesis Example 4 [Synthesis of Resin E4]
A 4-necked flask equipped with a condenser and a stirrer was charged with 4.60 parts of 1,4-dioxane, and the temperature was raised to 60 ° C. Monomer I (manufactured by Central Glass Co., Ltd.) 15.00 parts, monomer X (manufactured by Central Glass Co., Ltd.) 9.98 parts [molar ratio; monomer I: monomer X = 90: 10] and azobis-2,4-dimethylvalero A solution prepared by dissolving 0.243 parts of nitrile in 15.63 parts of 1,4-dioxane was added dropwise over 1 hour. Thereafter, stirring was continued for 5 hours while maintaining 60 ° C. The reaction solution was cooled to 40 ° C. Next, 499 parts of n-heptane was cooled to 10 ° C., and the reaction solution was poured therein to precipitate a resin. The resin collected by filtration was dissolved in 49.8 parts of tetrahydrofuran. Further, a resin dissolved in 499 parts of n-heptane cooled to 10 ° C. was poured to precipitate the resin. The precipitated resin was collected by filtration and dried under reduced pressure to obtain 18.3 parts of a resin having a weight average molecular weight of 5.6 × 10 ³ . This resin is referred to as a resin E4. This resin E4 has the following structural units.

Synthesis Example 5 [Synthesis of Resin A1]
A 4-necked flask equipped with a condenser and a stirrer was charged with 92.8 parts of 1,4-dioxane and 16.7 parts of monomer A, and the temperature was raised to 85 ° C. Thereto monomer M60.0 parts, monomer A 39.0 parts, monomer C 9.22 parts, monomer N 4.06 parts, monomer D 26.6 parts [molar ratio; monomer M: monomer A: monomer C: monomer N: monomer D = 40: 30: 5: 5: 20] and a solution of 11.5 parts of azobisisobutyronitrile in 138.5 parts of 1,4-dioxane was added dropwise over 1 hour. Thereafter, stirring was continued for 6 hours while maintaining 85 ° C. After the reaction solution was cooled to 40 ° C., a mixed solution of 1609 parts of methanol and 402 parts of water was sufficiently cooled, and the reaction solution was poured therein to precipitate a resin. The obtained resin was dissolved in methyl isobutyl ketone, and 3.09 parts of p-toluenesulfonic acid and 309.4 parts of water were added and stirred for 6 hours. The organic layer recovered by standing and liquid separation was washed with water about three times, and then the washed organic layer was poured into 2010 parts of n-heptane to precipitate a resin. The precipitated resin was collected by filtration and dried under reduced pressure to obtain 129 parts of a resin having a weight average molecular weight of 5.2 × 10 ³ . This resin is referred to as Resin A1. This resin A1 has the following structural units.

Synthesis Example 6 [Synthesis of Resin A2]
A four-necked flask equipped with a condenser and a stirrer was charged with 15.1 parts of 1,4-dioxane and heated to 85 ° C. Monomer M12.0 parts, monomer B 4.65 parts, monomer E 5.85 parts, monomer F 1.39, monomer N 1.30 parts [molar ratio; monomer M: monomer B: monomer E: monomer F: monomer N = 50 : 15: 20: 5: 10] and a solution prepared by dissolving 1.84 parts of azobisisobutyronitrile in 22.7 parts of 1,4-dioxane was added dropwise over 1 hour. Thereafter, stirring was continued for 6 hours while maintaining 85 ° C. After cooling the reaction solution to 40 ° C., a mixed solution of 262 parts of methanol and 65 parts of water was sufficiently cooled, and the reaction solution was poured into this to precipitate a resin. The obtained resin was dissolved in methyl isobutyl ketone, 0.50 parts of p-toluenesulfonic acid and 50.4 parts of water were added and stirred for 6 hours. The organic layer recovered by standing and liquid separation was washed with water about three times, and then the washed organic layer was poured into 327 parts of n-heptane to precipitate a resin. The precipitated resin was collected by filtration and dried under reduced pressure to obtain 18.1 parts of a resin having a weight average molecular weight of 4.9 × 10 ³ . This resin is referred to as Resin A2. This resin A2 has the following structural units.

Synthesis Example 7 [Synthesis of Resin A3]
In a four-necked flask equipped with a condenser and a stirrer, 15.0 parts of monomer B, 3.57 parts of monomer C, 3.36 parts of monomer H and 5.14 parts of monomer D [molar ratio; monomer B: monomer C: monomer H: monomer D = 50: 12.5: 12.5: 25], and 40.6 parts of 1,4-dioxane was added to obtain a solution. Thereto were added 0.2 parts of azobisisobutyronitrile and 0.9 part of azobis (2,4-dimethylvaleronitrile) as initiators, and the mixture was heated at 77 ° C. for about 5 hours. Thereafter, the reaction solution is poured into a large amount of water-containing methanol to precipitate it, and then purified by performing the operation of washing the precipitate with a large amount of water-containing methanol three times to obtain a resin having a weight average molecular weight of 8.1 × 10 ^3. Obtained 1 part. This is designated as resin A3. This resin A3 has the following structural units.

Synthesis Example 8 [Synthesis of Resin H]
In a four-necked flask equipped with a condenser and a stirrer, 10.00 parts of monomer B, 3.26 parts of monomer C, 7.42 parts of monomer G, 3.92 parts of monomer D and 7.72 parts of monomer K [molar ratio; monomer B: monomer C: monomer G: monomer D: monomer K = 35: 12: 23: 20: 10], and 48.4 parts of 1,4-dioxanedioxane was added to obtain a solution. Thereto were added 0.23 part of azobisisobutyronitrile and 1.03 part of azobis (2,4-dimethylvaleronitrile) as initiators, and the mixture was heated at 73 ° C. for about 5 hours. Thereafter, the reaction solution is poured into a large amount of methanol to precipitate it, and then purified by performing the operation of washing the precipitate with a large amount of methanol three times to obtain a copolymer having a weight average molecular weight of 2.1 × 10 ^3. Obtained in 8 parts. This resin is referred to as Resin H. This resin H has the following structural units.

Examples 1-16 and Comparative Examples 1-4
(Preparation of resist composition)
Each of the components shown below was mixed in parts by mass shown in Table 1 and dissolved in the following solvent, and then filtered through a fluororesin filter having a pore size of 0.2 μm to prepare resist compositions 1 to 19 and H1. .

Each code | symbol shown in Table 1 represents the following compounds.
<Resin (A)>
A1: Resin A1
A2: Resin A2
A3: Resin A3
E1: Resin E1
E2: Resin E2
E3: Resin E3
E4: Resin E4
H: Resin H

Ｂ２：式（Ｂ−２）で表される塩；特開２０１１−１２６８６９号公報記載の方法で合成

Ｂ３：式（Ｂ−３）で表される塩；特開２００７−２２４００８号公報記載の方法で合成

Ｂ４：セントラル硝子社製

<Acid generator>
B1: salt represented by formula (B-1); synthesized by the method described in JP-A-2008-74843

B2: salt represented by formula (B-2); synthesized by the method described in JP2011-126869A

B3: salt represented by formula (B-3); synthesized by the method described in JP-A-2007-224008

B4: Central Glass

Ｃ２：式（Ｃ９−２）で表される塩；（東京化成工業（株）製）

Ｃ３：式（Ｃ９−３）で表される塩；特開２０１１−３９５０２号公報記載の方法で合成

Ｃ４：式（Ｃ１１−１）で表される塩；特開２０１２−７２１０９号記載の方法で合成

Ｃ５：テトラブチルアンモニウムヒドロキシド（東京化成工業（株）製）
Ｃ６：２，６−ジイソプロピルアニリン（東京化成工業（株）製） <Quencher (C)>
C1: salt represented by the formula (C9-1); synthesized by the method described in JP2011-39502A

C2: salt represented by formula (C9-2); (manufactured by Tokyo Chemical Industry Co., Ltd.)

C3: salt represented by the formula (C9-3); synthesized by the method described in JP2011-39502A

C4: salt represented by the formula (C11-1); synthesized by the method described in JP2012-72109A

C5: Tetrabutylammonium hydroxide (manufactured by Tokyo Chemical Industry Co., Ltd.)
C6: 2,6-diisopropylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Solvent>
Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 150 parts γ-butyrolactone 5 parts

(Electron beam exposure evaluation of resist composition)
A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 ° C. for 60 seconds. This silicon wafer was spin-coated with a resist composition so that the film thickness of the composition layer was 0.04 μm. Thereafter, the composition layer was formed by pre-baking on a direct hot plate for 60 seconds at the temperature shown in the “PB” column of Table 1. The wafer on which the composition layer was formed was exposed to a line-and-space pattern using an electron beam drawing machine (“HL-800D 50 keV” manufactured by Hitachi, Ltd.) while changing the exposure stepwise.
After exposure, post exposure baking is performed for 60 seconds on the hot plate at the temperature shown in the “PEB” column of Table 1, and then paddle development is performed for 60 seconds with an aqueous 2.38 mass% tetramethylammonium hydroxide solution. A resist pattern was obtained.
The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the exposure amount at which the line width and space width of the line and space pattern having a line width of 100 nm were 1: 1 was defined as effective sensitivity.

Resolution evaluation: The resist pattern obtained at the above-mentioned effective sensitivity was observed with a scanning electron microscope, and the minimum line width at which the resist pattern was resolved without falling was defined as the resolution. The results are shown in Table 2.
Fall margin evaluation: For a 60 nm line and space pattern, the fall margin was determined according to the following formula. As the value is larger, the tilt is less likely to occur and the exposure amount adjustment for pattern formation is easier. The results are shown in Table 2.
Fall margin (%) = (E ₂ −E ₁ ) / E ₁ × 100
[E ₁ represents the minimum exposure amount at which the resist pattern is separated.
E ₂ represents the maximum exposure amount to be formed without the resist pattern from falling down. ]

Examples 17-22
(EUV exposure evaluation of resist composition)
An 8-inch silicon wafer was treated with hexamethyldisilazane at 90 ° C. for 60 seconds on a direct hot plate. This silicon wafer was spin-coated with a resist composition so that the film thickness of the composition layer was 0.035 μm.
Thereafter, the composition layer was formed by pre-baking on a direct hot plate for 60 seconds at the temperature shown in the “PB” column of Table 1. Using a reflective mask capable of forming a 1: 1 line and space with a dimension of 24 nm or 22 nm on a wafer and an EUV exposure machine (NA 0.3, exposure with a dipole), the exposure amount is changed stepwise, and the wafer A line and space pattern was exposed on the composition layer.
After exposure, post exposure bake on the hot plate at the temperature shown in the column “PEB” in Table 1 for 60 seconds, and further paddle development with 2.38 mass% tetramethylammonium hydroxide aqueous solution for 30 seconds A resist pattern was obtained.
The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the exposure amount at which the line width and space width of the line and space pattern having a line width of 24 nm were 1: 1 was defined as effective sensitivity.

  Resolution evaluation: The resist pattern obtained at the effective sensitivity in EUV exposure was observed with a scanning electron microscope, and the minimum line width at which the resist pattern was resolved without falling was defined as the resolution. The results are shown in Table 3.

  According to the resist composition of the present invention, a high-resolution resist pattern can be easily produced.

Claims (8)

A resin (E) comprising a structural unit having a group represented by formula (I) and a structural unit having a group represented by formula (II);
A resin (A) having an acid labile group and having increased solubility in an alkaline aqueous solution by the action of the acid;
An acid generator (B),
Content of the said resin (E) is a resist composition which is 5 to 30 mass% per 100 mass parts of said resin (A).

[In formula (I), ^{R 1} represents an alkyl group having 1 to 6 carbon atoms containing a fluorine atom. ]

[In Formula (II), R ² and R ³ each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
Z1 ⁺ represents an organic cation. ] The resist composition according to claim 1, wherein the structural unit having a group represented by formula (I) is a structural unit represented by formula (I-1).

[In the formula (I-1),
R ^1x represents a C 1-6 alkyl group containing a fluorine atom.
R ⁴ represents a hydrogen atom or a methyl group.
X ¹ represents a divalent saturated hydrocarbon group having 1 to 10 carbon atoms. ] The structural unit having a group represented by the formula (II) is a structural unit represented by the formula (II-1) or a structural unit represented by the formula (II-2). Resist composition.

[In Formula (II-1) and Formula (II-2),
R ^2x , R ^3x , R ^2y and R ^3y each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
R ⁶ and R ⁷ each independently represent a hydrogen atom or a methyl group.
X ² and X ³ each independently represent a divalent linking group.
Z2 ⁺ and Z3 ⁺ represent an organic sulfonium cation or an organic iodonium cation. ] The resist composition according to any one of claims 1 to 3, wherein the structural unit having a group represented by the formula (II) is a structural unit represented by the formula (II-3).

[Wherein, R ¹³ represents a hydrogen atom or a methyl group.
u represents 1 or 2;
R ¹⁴ represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
X ¹⁵ represents an alkanediyl group having 1 to 6 carbon atoms.
Z4 ⁺ represents an organic sulfonium cation or an organic iodonium cation. ]   Furthermore, the resist composition of any one of Claims 1-4 containing a quencher. (1) The process of apply | coating the resist composition of any one of Claims 1-5 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer using an exposure machine;
(4) a step of heating the composition layer after exposure; and
(5) a step of developing the composition layer after heating;
A method for producing a resist pattern including: Formula (I)

[Wherein, R ¹ represents a C 1-6 alkyl group containing a fluorine atom. ]
A structural unit having a group represented by:
Formula (II-1)

[Where:
R ^2x and R ^3x each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
R ⁶ represents a hydrogen atom or a methyl group.
X ² represents a divalent linking group.
Z2 ⁺ represents an organic sulfonium cation or an organic iodonium cation. ]
Resin containing the structural unit represented by these. The resin according to claim 7, wherein the structural unit having a group represented by the formula (I) is a structural unit represented by the formula (I-1).

[In the formula (I-1),
R ^1x represents a C 1-6 alkyl group containing a fluorine atom.
R ⁴ represents a hydrogen atom or a methyl group.
X ¹ represents a divalent saturated hydrocarbon group having 1 to 10 carbon atoms. ]