JP2014029525A - Method for producing resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a resist pattern with good DOF (depth of focus, focus margin).SOLUTION: The method for producing a resist pattern includes steps of applying the following resist composition on a substrate, drying the applied resist composition to form a composition layer, exposing the composition layer, heating the composition layer after exposed, and developing the composition layer after heated by using a negative developing solution. The resist composition comprises a resin including a structural unit having an acid-labile group, an acid generator expressed by formula (I), and an acid generator expressed by formula (II). In formula (I), Xrepresents an alkanediyl group; Reach represents a hydrocarbon group; and Zrepresents an organic cation. In formula (II), Z1represent an organic cation; Rand Reach represent a fluorine atom or a perfluoroalkyl group; Xrepresents a divalent saturated hydrocarbon group; and Rrepresents a group including a cyclic ether structure.

Description

  The present invention relates to a resist pattern manufacturing method.

Development of deep ultraviolet lithography technology using an ArF excimer laser or the like as an exposure source is being actively carried out in the manufacture of semiconductors with higher integration. As a method for producing a resist pattern used in such deep ultraviolet lithography technology, for example,
(A) A resist composition for negative development, which contains a resin whose polarity is increased by the action of an acid, and which increases its solubility in a positive developer and decreases its solubility in a negative developer by irradiation with actinic rays or radiation. Applying an object and forming a resist film having a receding contact angle with respect to water of 70 degrees or more,
(A) a step of exposing through an immersion medium, and (c) a step of developing using a negative developer,
Patent Document 1 discloses a method of forming a resist pattern including

JP 2008-309879 A

  An object of the present invention is to provide a method of manufacturing a resist pattern having an excellent focus margin (DOF).

［式（Ｉ）中、
Ｘ²は、炭素数１〜６のアルカンジイル基を表し、該アルカンジイル基に含まれる水素原子は、ヒドロキシ基又は−ＯＲ⁵で置換されていてもよく、該アルカンジイル基を構成するメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。
Ｒ⁴及びＲ⁵は、それぞれ独立に、炭素数１〜２４の炭化水素基を表し、該炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよく、該炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。
Ｚ^＋は、有機カチオンを表す。］

［式（ＩＩ）中、
Ｒ^II3及びＲ^II4は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｘ^II1は、２価の炭素数１〜１７の飽和炭化水素基を表し、前記２価の飽和炭化水素基に含まれる水素原子は、フッ素原子で置換されていてもよく、前記２価の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いてもよい。
Ｒ^II5は、環状エーテル構造を含む基を表す。
Ｚ１^＋は、有機カチオンを表す。］
〔２〕ネガ型現像液は、酢酸ブチル及び２−ヘプタノンのうち少なくとも１種を含む溶媒である〔１〕記載の製造方法。
〔３〕前記工程（５）が、ダイナミックディスペンス法により現像する工程である〔１〕又は〔２〕記載のレジストパターンの製造方法。
〔４〕式（Ｉ）で表される酸発生剤が式（ＩＡ）で表される酸発生剤である〔１〕〜〔３〕のいずれか記載のレジストパターンの製造方法。

［式（ＩＡ）中、Ｘ²及びＺ^＋は、上記と同じ意味を表す。
Ｒ⁶は、炭素数１〜１７の炭化水素基を表し、該炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよく、該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で置き換わっていてもよい。
Ｒ⁷は、炭素数１〜６のアルキル基を表す。
Ｒ⁸は、炭素数１〜６のフッ素化アルキル基を表す。
ただし、Ｒ⁶、Ｒ⁷及びＲ⁸の合計炭素数は、２０以下である。］
〔５〕Ｒ^II5が、式（ＩＩＡ）で表される基又は式（ＩＩＥ）で表される基である〔１〕〜〔４〕のいずれか記載のレジストパターンの製造方法。

［式（ＩＩＡ）及び式（ＩＩＥ）中、
ｓ１は、１〜４の整数を表す。ｔ１は、０〜２の整数を表す。但し、ｓ１＋ｔ１は、１〜４である。
ｓ１１は、１〜４の整数を表す。ｔ１１は、０〜２の整数を表す。
ｓ１２は、１〜４の整数を表す。ｔ１２は、０〜２の整数を表す。但し、ｓ１２＋ｔ１２は、０〜４である。
Ｒ^II6は、炭素数１〜１２の飽和炭化水素基又は炭素数６〜１８の芳香族炭化水素基を表し、前記飽和炭化水素基及び前記芳香族炭化水素基に含まれる水素原子は、炭素数１〜６のアルキル基又はニトロ基で置換されていてもよく、Ｒ^II6の２つが互いに結合して環を形成してもよく、前記飽和炭化水素基及び環に含まれるメチレン基は、酸素原子で置き換わっていてもよい。
ｕ１は、０〜８の整数を表し、ｕ１が２以上である場合、複数のＲ^II6は同一又は相異なる。
Ｒ^II7及びＲ^II8は、それぞれ独立に、ヒドロキシ基、ハロゲン基、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１〜６のヒドロキシアルキル基、炭素数２〜７のアシル基、炭素数２〜７のアシルオキシ基又は炭素数２〜７のアシルアミノ基を表し、Ｒ^II7及びＲ^II8の２つが互いに結合して単結合又は環を形成してもよい。
ｕ２及びｕ３は、それぞれ独立に、０〜１６の整数を表し、ｕ２が２以上である場合、複数のＲ^II7は同一又は相異なり、ｕ３が２以上である場合、複数のＲ^II8は同一又は相異なる。
＊はＸ¹との結合手である。］ The present invention includes the following inventions.
[1] (1) A step of applying a resist composition on a substrate,
(2) a step of drying the resist composition after coating to form a composition layer;
(3) a step of exposing the composition layer;
(4) a step of heating the composition layer after exposure; and (5) a method for producing a resist pattern comprising a step of developing the composition layer after heating with a negative developer,
Resist pattern wherein the resist composition is a resin containing a structural unit having an acid labile group, an acid generator represented by formula (I), and an acid generator represented by formula (II) Manufacturing method.

[In the formula (I),
X ² represents an alkanediyl group having 1 to 6 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a hydroxy group or —OR ⁵ , and a methylene group constituting the alkanediyl group May be replaced by an oxygen atom or a carbonyl group.
R ⁴ and R ⁵ each independently represent a hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the group may be replaced with an oxygen atom or a carbonyl group.
Z ⁺ represents an organic cation. ]

[In the formula (II),
R ^II3 and R ^II4 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
X ^II1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and the divalent saturated The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
R ^II5 represents a group containing a cyclic ether structure.
Z1 ⁺ represents an organic cation. ]
[2] The production method according to [1], wherein the negative developer is a solvent containing at least one of butyl acetate and 2-heptanone.
[3] The method for producing a resist pattern according to [1] or [2], wherein the step (5) is a step of developing by a dynamic dispensing method.
[4] The method for producing a resist pattern according to any one of [1] to [3], wherein the acid generator represented by the formula (I) is an acid generator represented by the formula (IA).

[In formula (IA), X ² and Z ⁺ represent the same meaning as described above.
R ⁶ represents a hydrocarbon group having 1 to 17 carbon atoms, the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the methylene group constituting the hydrocarbon group is May be replaced by an oxygen atom or a carbonyl group.
R ⁷ represents an alkyl group having 1 to 6 carbon atoms.
R ⁸ represents a fluorinated alkyl group having 1 to 6 carbon atoms.
However, the total carbon number of R ⁶ , R ⁷ and R ⁸ is 20 or less. ]
[5] The method for producing a resist pattern according to any one of [1] to [4], wherein R ^II5 is a group represented by the formula (IIA) or a group represented by the formula (IIE).

[In Formula (IIA) and Formula (IIE),
s1 represents an integer of 1 to 4. t1 represents the integer of 0-2. However, s1 + t1 is 1-4.
s11 represents an integer of 1 to 4. t11 represents an integer of 0 to 2.
s12 represents an integer of 1 to 4. t12 represents an integer of 0 to 2. However, s12 + t12 is 0-4.
R ^II6 represents a saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group and the aromatic hydrocarbon group has a carbon number 1 to 6 alkyl groups or nitro groups may be substituted, and two of R ^II6 may be bonded to each other to form a ring, and the saturated hydrocarbon group and the methylene group contained in the ring are each an oxygen atom It may be replaced with.
u1 represents an integer of 0 to 8, and when u1 is 2 or more, the plurality of R ^II6 are the same or different.
R ^II7 and R ^II8 are each independently a hydroxy group, a halogen group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, 2 to 7 carbon atoms acyl group, represents an acyloxy group, or an acylamino group having 2 to 7 carbon atoms having 2 to 7 carbon atoms, may form a two but a single bond or a ring bonded to each other of R ^II7 and R ^II8.
u2 and u3 are independently an integer of 0 to 16, if u2 is 2 or more, the plurality of R ^II7 same or different, when u3 is 2 or more, plural R ^II8 are the same or Different.
* Represents a bond to X ^1. ]

  According to the resist pattern manufacturing method of the present invention, a resist pattern having an excellent focus margin can be manufactured.

At least one monomer having the term "(meth) acrylic monomer" monomer and _{"CH 2 = C (CH 3)} -CO- " having "CH ₂ = CH-CO-" in the molecule herein Means. 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.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) A step of applying a resist composition on a substrate (hereinafter sometimes referred to as “step (1)”);
(2) A step of drying the resist composition after coating to form a composition layer (hereinafter sometimes referred to as “step (2)”);
(3) a step of exposing the composition layer (hereinafter sometimes referred to as “step (3)”);
(4) A step of heating the composition layer after exposure (hereinafter sometimes referred to as “step (4)”);
(5) A step of developing the heated composition layer with a negative developer (hereinafter sometimes referred to as “step (5)”) is included. Each step will be described below.

<Step (1)>
In step (1), a resist composition is applied on the substrate. The substrate is not particularly limited, and examples thereof include inorganic substrates usually used for manufacturing semiconductors such as silicon, SiN, SiO ₂ and SOG. These substrates may be cleaned, or may be those in which an antireflection film or the like is formed on an inorganic substrate. The antireflection film can be formed using, for example, a commercially available composition for organic antireflection films.
Application of the resist composition onto the substrate can be performed by a coating apparatus widely used in the resist field, such as a spin coater. The resist composition used in step (1) will be described later.

<Step (2)>
In the step (2), the composition layer is formed by drying the resist composition applied on the substrate. The drying is performed by, for example, a heating means using a heating device such as a hot plate (so-called pre-baking), a decompression means using a decompression device, or a combination of these means. is there. The conditions for the heating means and the decompression means can be selected according to the type of solvent contained in the resist composition.
In the case of a heating means, the drying temperature is preferably 50 to 200 ° C, more preferably 60 to 150 ° C. The drying time is preferably 10 to 180 seconds, more preferably 30 to 120 seconds.
In the case of the decompression means, the resist composition coated on the substrate is sealed in a decompression dryer, and then dried at an internal pressure of 1 to 1.0 × 10 ⁵ Pa.
The film thickness of the composition layer thus formed is generally 20 to 1000 nm, preferably 50 to 400 nm. The film thickness can be adjusted by variously adjusting the conditions of the coating apparatus.

<Step (3)>
In step (3), the composition layer is preferably exposed using an exposure machine. The exposure machine may be an immersion exposure machine. The exposure is performed through a mask (photomask) on which a desired pattern is formed. As an exposure light source for an exposure machine, an apparatus that emits ultraviolet light such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ excimer laser (wavelength 157 nm), an electron beam, or an ultra-ultraviolet light Various types are used such as those that irradiate (EUV), those that emit laser light from a solid-state laser light source (such as YAG or a semiconductor laser) and radiate far-wave or vacuum ultraviolet harmonic laser light. be able to. When an electron beam is used as the exposure light source, the composition layer may be directly irradiated and drawn without using a mask. As the exposure light source used in the production method of the present invention, an ArF excimer laser is preferable.
By exposure through a mask, an acid is generated from the acid generator contained in the composition layer. By the action of this acid, a hydrophilic group is formed from the acid labile group of the resin.

The exposure is preferably performed by a method in which the immersion medium is placed on the composition layer, so-called immersion exposure. When performing immersion exposure, you may perform the process of wash | cleaning the surface of the composition layer before exposure and / or after exposure with an aqueous chemical | medical solution.
The immersion medium used for the immersion exposure is transparent to the exposure wavelength of the ArF excimer laser, and can have a temperature coefficient of refractive index so as to minimize distortion of the optical image projected onto the composition layer. A liquid that is as small as possible is preferable, and water, particularly ultrapure water, is preferable because it is easily available and easy to handle. When water is used as the immersion medium, an additive that decreases the surface tension of the water and increases the surface activity may be added to the water in a small proportion. This additive is preferably one that does not dissolve the composition layer and can ignore the influence on the optical coating on the lower surface of the lens element.
The exposure amount can be appropriately set according to the resist composition to be used, the type of resist pattern to be produced, and the type of exposure light source, and is preferably 5 to 50 mJ / cm ² .
Step (3) may be repeated a plurality of times. The exposure light source and the exposure method when performing multiple exposures may be the same or different.

<Process (4)>
The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection group reaction of the resin. The heating in the step (4) includes a heating means using a heating device such as a hot plate. The heating temperature is preferably 50 to 200 ° C, more preferably 70 to 150 ° C. The heating time is preferably 10 to 180 seconds, more preferably 30 to 120 seconds.
The reaction of the acid labile group is promoted by the step (4).

<Step (5)>
Step (5) is a step of developing the heated composition layer with a negative developer. That is, negative development of the composition layer after heating is performed in the step (5).
In step (5), development is preferably performed using a developing device.

The negative developer means a solvent that dissolves the unexposed composition layer and is insoluble or hardly soluble in the exposed composition layer. The negative developer is preferably an organic solvent. Examples of the organic solvent include polar solvents such as ketone solvents, ester solvents, amide solvents, and ether solvents, and hydrocarbon solvents.
Examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, diisobutylketone, cyclohexanone, methylcyclohexanone, phenylacetone, and methylisobutylketone.
Examples of ester solvents include butyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, Examples include 3-methyl-3-methoxybutyl acetate, butyl formate, propyl formate, ethyl lactate, butyl lactate, and propyl lactate.
Examples of the ether solvent include ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, and triethylene glycol monoethyl ether.
Examples of the amide solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide and the like.
Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents such as octane and decane.
The negative developer preferably contains an organic solvent selected from the group consisting of a ketone solvent, an ester solvent and an ether solvent among the above organic solvents, and is selected from the group consisting of a ketone solvent and an ester solvent. It is more preferable that at least one of butyl acetate and 2-heptanone is included.
The developer may contain a solvent other than butyl acetate and 2-heptanone. Examples of such solvents include ketone solvents such as 2-hexanone; ester solvents such as propylene glycol monomethyl ether acetate; amide solvents such as N, N-dimethylacetamide; ether solvents such as propylene glycol monomethyl ether and glycol ether. May contain a polar solvent, a hydrocarbon solvent such as anisole, etc., or may contain water if there is a slight amount.
The total content of butyl acetate and 2-heptanone is preferably 50% by mass or more based on the total amount of the developer, and is substantially at least one selected from the group consisting of butyl acetate and 2-heptanone. preferable. Further, it is more preferable that the developer is substantially only butyl acetate or substantially only 2-heptanone. As these developing solutions, those commercially available as solvents may be used as they are.

  The developer may contain a surfactant as necessary. The surfactant is not particularly limited, and may be an ionic surfactant or a nonionic surfactant, and a fluorosurfactant or a silicon surfactant may be used.

As a developing method, the composition layer after step (4) is immersed in a tank filled with a developer for a certain period of time together with the substrate (dip method), and the composition layer after step (4) is developed. A method in which the liquid is raised by surface tension and developed by standing for a certain time (paddle method), a method in which the developer is sprayed on the surface of the composition layer after step (4) (spray method), and a composition after step (4) Examples include a method (dynamic dispensing method) in which the substrate on which the physical layer is formed is rotated at a constant speed, and the developer is continuously applied while scanning the application nozzle at a constant speed.
Among them, the developing method is preferably a paddle method or a dynamic dispensing method, and more preferably a dynamic dispensing method.
The development temperature is preferably 5 to 60 ° C, more preferably 10 to 40 ° C. The development time is preferably 5 to 300 seconds, and more preferably 5 to 90 seconds. When developing with the dynamic dispensing method, the developing time is particularly preferably 5 to 20 seconds, and when developing with the paddle method, the developing time is particularly preferably 20 to 60 seconds.
The exposed portion of the composition layer becomes insoluble or hardly soluble in the developer due to the reaction of the acid labile group described above. Therefore, when the composition layer is brought into contact with the developer, the unexposed portion of the composition layer is caused by the developer. The negative resist pattern is manufactured by removing the resist pattern.

  After the development time has elapsed, the development may be stopped while replacing the developer in contact with the composition layer with a solvent of a different type from the developer. In addition, in order to remove the developer remaining on the resist pattern, it is preferable to wash the developed resist pattern using a rinse solution. The rinsing liquid is not particularly limited as long as it does not dissolve the produced resist pattern, and a general organic solvent can be used, but an alcohol solvent or an ester solvent is preferably used, and hexanol, pen C1-C8 monohydric alcohols such as butanol and butanol are more preferred.

<Resist composition>
The resist composition (hereinafter simply referred to as “resist composition”)
A resin comprising a structural unit having an acid labile group (hereinafter sometimes referred to as “resin (A)”),
An acid generator represented by formula (I) (hereinafter sometimes referred to as “acid generator (I)”), and
It contains an acid generator represented by the formula (II) (hereinafter sometimes referred to as “acid generator (II)”).
It is preferable that the resist composition further contains a solvent (E).
It is preferable that the resist composition further contains a basic compound (C).
The resist composition used in step (1) is a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or an EUV exposure. Any of a resist composition and a resist composition for immersion exposure may be used.

<Resin (A)>
The resin (A) includes a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a)”). Furthermore, a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”) may be included.
In the present specification, the “acid labile group” is a group having a leaving group and forming a hydrophilic group (for example, a hydroxy group or a carboxy group) by leaving the leaving group by contact with an acid. Means.

［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、炭素数３〜２０の脂環式炭化水素基又はこれらを組み合わせた基を表すか、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する。＊は結合手を表す。］

［式（２）中、Ｒ^a1’及びＲ^a2’は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^a3’は、炭素数１〜２０の炭化水素基を表すか、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価の炭化水素基を構成する−ＣＨ₂−は、−Ｏ―又は―Ｓ−で置き換わってもよい。 <Structural unit (a)>
The structural unit (a) is a structural unit having an acid labile group. It is preferable that the resin (A) has a characteristic that it is decomposed by the action of an acid and the solubility in butyl acetate or 2-heptanone is reduced.
Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2).

[In the formula (1), R ^a1 , R ^a2 and R ^a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof. R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms. * Represents a bond. ]

[In 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 ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — constituting the hydrocarbon group and the divalent hydrocarbon group. May be replaced by -O- or -S-.

アルキル基と脂環式炭化水素基とを組合わせた基としては、例えば、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基等が挙げられる。 ^Examples of the alkyl group represented by R ^a1 , R ^a2 and R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group represented by R ^a1 , R ^a2 and R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups (* 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 the group obtained by combining an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.

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. In each formula, R ^a3 has the same meaning as described above, and * represents a bond to —O—.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (a group in which R ^a1 , R ^a2 and R ^a3 are alkyl groups in the formula (1), preferably tert-butoxycarbonyl). Group), 2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and the carbon atom to which they are bonded form an adamantyl group, and R ^a3 is an alkyl group) and 1- (adamantan-1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

Examples of the hydrocarbon group represented by R ^{a1 ′} , R ^{a2 ′} and R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group obtained by combining these.
Examples of the alkyl group and alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the divalent hydrocarbon group R ^{a2 'and} R ^a3' is formed by bonding with, for example, R ^{a1 ',} R ^a2' is one obtained by removing groups a hydrogen atom from a hydrocarbon group and R ^{a3 '} Can be mentioned.
At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

Specific examples of the group represented by the formula (2) include the following groups. * Represents a bond.

  The monomer for deriving the structural unit (a) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth) acrylic monomer having an acid labile group.

  Among the (meth) acrylic monomers having an acid labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. If a resin having a structural unit (a) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

  As a structural unit derived from a (meth) acrylic monomer having a group represented by formula (1), preferably a structural unit represented by formula (a1-1) or a structure represented by formula (a1-2) Units are listed. These may be used alone or in combination of two or more. In this specification, the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2) are represented by the structural unit (a1-1) and the structural unit (a1-2), respectively. The monomer that derives the structural unit (a1-1) and the monomer that derives the structural unit (a1-2) may be referred to as a monomer (a1-1) and a monomer (a1-2), respectively.

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−を表し、ｋ１は１〜７の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合わせた基を表す。
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。］

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group obtained by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

L ^a1 and L ^a2 are preferably —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, more preferably —O—. k1 is preferably an integer of 1 to 4, more preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the alkyl group of R ^a6 and R ^a7 , the alicyclic hydrocarbon group, and the group obtained by combining these include the same groups as the groups represented by R ^a1 , R ^a2, and R ^a3 in formula (1). .
The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group of R ^a6 and R ^a7 preferably has 8 or less carbon atoms, more preferably 6 or less.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As a monomer (a1-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Among these, a monomer represented by any one of formula (a1-1-1) to formula (a1-1-8) is preferable, and any one of formula (a1-1-1) to formula (a1-1-4) is preferable. The monomer represented by is more preferable.

Examples of the monomer (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethylcycloheptan-1-yl (meth). Acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, 1-methylcyclohexane-1-yl (meth) acrylate, 1-isopropylcyclopentan-1-yl (meth) acrylate, 1-isopropylcyclohexane-1- And yl (meth) acrylate. Monomers represented by the formula (a1-2-1) to the formula (a1-2-12) are preferred, and the formula (a1-2-3) to the formula (a1-2-4) or the formula (a1-2-9) The monomer represented by formula (a1-2-10) is more preferable, and the monomer represented by formula (a1-2-3) or formula (a1-2-9) is more preferable.

  When the resin (A) contains the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is usually 10 to 95 mol with respect to all the structural units of the resin (A). %, Preferably 15 to 90 mol%, more preferably 20 to 85 mol%.

［式（ａ１−５）中、
Ｒ³¹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。
Ｚ^a1は、単結合又は＊−［ＣＨ₂］_k4−ＣＯ−Ｌ^a54−を表す。ここで、ｋ４は１〜４の整数を表す。＊は、Ｌ^a51との結合手を表す。
Ｌ^a51、Ｌ^a52、Ｌ^a53及びＬ^a54は、それぞれ独立に、−Ｏ−又は−Ｓ−を表す。
ｓ１は、１〜３の整数を表す。
ｓ１’は、０〜３の整数を表す。］ As a structural unit derived from a (meth) acrylic monomer having a group represented by the formula (2), a structural unit represented by the formula (a1-5) (hereinafter referred to as “structural unit (a1-5)”) There are).

[In the formula (a1-5),
R ³¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or * — [CH ₂ ] _k4 —CO—L ^a54 —. Here, k4 represents an integer of 1 to 4. * Represents a bond with L ^a51 .
L ^a51 , L ^a52 , L ^a53 and L ^a54 each independently represent —O— or —S—.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3. ]

In formula (a1-5), R ³¹ is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ^a51 is preferably an oxygen atom.
One of L ^a52 and L ^a53 is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

Examples of the monomer that leads to the structural unit (a1-5) include the following monomers.

  When resin (A) has a structural unit (a1-5), the content rate is preferable 1-50 mol% with respect to all the structural units of resin (A), and 3-45 mol% is more preferable. 5 to 40 mol% is more preferable.

<Structural unit (s)>
The monomer for deriving the “structural unit (s)” which is a structural unit having no acid labile group is not particularly limited as long as it is a monomer having no acid labile group, and a known monomer in the resist field can be used. .
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid labile group is preferable. A structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring and having no acid labile group If a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”) is used for the resist composition, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When the resist composition is applied to KrF excimer laser exposure (248 nm), high energy beam exposure such as electron beam or EUV (extreme ultraviolet light), the structural unit (a2) having a phenolic hydroxy group as the structural unit (a2) ) Is preferably used. When applied to ArF excimer laser exposure (193 nm) or the like, the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group, and more preferably a structural unit (a2-1). As the structural unit (a2), one type may be contained alone, or two or more types may be used in combination.

［式（ａ２−１）中、
Ｌ^a3は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−を表し、
ｋ２は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。］ Examples of the structural unit (a2) having an alcoholic hydroxy group include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as “structural unit (a2-1)”).

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

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

As a monomer which introduce | transduces structural unit (a2-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. A monomer represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferable, and represented by any one of formula (a2-1-1) to formula (a2-1-4). The monomer represented by Formula (a2-1-1) or Formula (a2-1-3) is more preferable.

  When resin (A) contains structural unit (a2-1), the content rate is 3 to 45 mol% normally with respect to all the structural units of resin (A), Preferably it is 1 to 40 mol%. More preferably, it is 1-35 mol%, More preferably, it is 2-20 mol%.

<Structural unit (a3)>
The lactone ring contained in the structural unit (a3) may be, for example, a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, and a bridged ring including these monocyclic lactone ring structures. But you can. Among these lactone rings, a γ-butyrolactone ring or a bridged ring containing a γ-butyrolactone ring structure is preferable.

  The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), or the formula (a3-3). These 1 type may be contained independently and 2 or more types may be contained.

［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。
Ｒ^a21は炭素数１〜４の脂肪族炭化水素基を表す。
ｐ１は０〜５の整数を表す。ｐ１が２以上のとき、複数のＲ^a21は互いに同一又は相異なる。
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。
Ｒ^a19は、水素原子又はメチル基を表す。
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す。
ｑ１は、０〜３の整数を表す。ｑ１が２以上のとき、複数のＲ^a22は互いに同一又は相異なる。
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。
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す。
ｒ１は、０〜３の整数を表す。ｒ１が２以上のとき、複数のＲ^a23は互いに同一又は相異なる。］

[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.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5. When p1 is 2 or more, the plurality of R ^a21 are the same 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.
R ^a19 represents a hydrogen atom or a methyl group.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, the plurality of R ^a22 are 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.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3. When r1 is 2 or more, the plurality of R ^a23 are the same or different from each other. ]

In Formula (a3-1), Formula (a3-2), and Formula (a3-3), L ^a4 , L ^a5, and L ^a6 are each independently preferably an oxygen atom or an integer of k3 of 1 to 4. A group represented by * —O— (CH ₂ ) _k3 —CO—O—, more preferably an oxygen atom and * —O—CH ₂ —CO—O—, still more preferably an oxygen atom.
R ^a18 , R ^a19 , R ^a20 and R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

  Examples of the monomer that leads to the structural unit (a3) include monomers described in JP 2010-204646 A. Formula (a3-1-1) to Formula (a3-1-4), Formula (a3-2-1) to Formula (a3-2-4), and Formula (a3-3-1) to Formula (a3-3) -4) is preferred, and the monomers represented by formula (a3-1-1) to formula (a3-1-2) and formula (a3-2-3) to formula (a3-2-4) are preferred. The monomer represented by either is more preferable, and the monomer represented by the formula (a3-1-1) or the formula (a3-2-3) is more preferable.

  When the resin (A) includes the structural unit (a3), the content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A). More preferably, it is 10-60 mol%.

The content of the structural unit (a) in the resin (A) is preferably in the range of 1 to 100 mol%, more preferably in the range of 10 to 95 mol%, with respect to all the structural units of the resin (A). The range of 90 mol% is more preferable, and the range of 20 to 85 mol% is particularly preferable.
Resin (A) which has structural unit (a) with such a content rate can be manufactured by adjusting the use molar amount of the monomer with respect to the total molar amount of all the monomers used at the time of resin (A) manufacture.

In the case where the resin (A) is a resin composed of the structural unit (a) and the structural unit (s), these content rates are respectively based on the total structural units of the resin (A),
Structural unit (a); 10-95 mol%
Structural unit (s); 5 to 90 mol% is preferable,
Structural unit (a); 15-90 mol%
Structural unit (s); 10 to 85 mol% is more preferable,
Structural unit (a); 20 to 85 mol%
Structural unit (s); 15 to 80 mol% is more preferable.

  The resin (A) preferably contains 15 mol% or more of structural units derived from the monomer having an adamantyl group (particularly the structural unit (a1-1)) with respect to the total structural units (a). When the content of the structural unit having an adamantyl group is large, the dry etching resistance of the resist pattern is improved.

The resin (A) is preferably a resin composed of the structural unit (a) and the structural unit (s).
The structural unit (a) is preferably at least one of the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), more preferably the structural unit (a1- 1).
The structural unit (s) is preferably at least one of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably the structural unit (a2-1). The structural unit (a3) is preferably at least one of the structural unit (a3-1) and the structural unit (a3-2).

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do.
The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 4,000 or more), 50,000 or less (more preferably 30,000 or less, and further preferably 15,000 or less).

<Resin other than resin (A)>
The resist composition used in the production method of the present invention includes at least one selected from resins other than the resin (A) described above, for example, a structural unit (s) and a structural unit derived from a known monomer used in the field. A seed-containing resin or the like may be contained.
When the resist composition used in the production method of the present invention contains a resin other than the resin (A), the content is usually 0.1 to 50 with respect to the total amount of the resin contained in the resist composition of the present invention. It is mass%, Preferably it is 0.5-30 mass%, More preferably, it is 1-20 mass%.

  In the resist composition used in the production method of the present invention, the total resin content is preferably 80% by mass or more and 99.9% by weight or less in the solid content of the resist composition. In the present specification, the “solid content in the composition” means the total of resist composition components excluding the solvent (E) described later. The solid content in the composition and the resin content relative thereto can be measured, for example, by a known analytical means such as liquid chromatography or gas chromatography.

［式（Ｉ）中、
Ｘ²は、炭素数１〜６のアルカンジイル基を表し、該アルカンジイル基に含まれる水素原子は、ヒドロキシ基又は−ＯＲ⁵で置換されていてもよく、該アルカンジイル基を構成する１以上のメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。
Ｒ⁴及びＲ⁵は、それぞれ独立に、炭素数１〜２４の炭化水素基を表し、該炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよく、該炭化水素基を構成する１以上のメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。
Ｚ^＋は、有機カチオンを表す。］ <Acid generator (I)>
The acid generator (I) is represented by the formula (I).

[In the formula (I),
X ² represents an alkanediyl group having 1 to 6 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a hydroxy group or —OR ⁵ , and one or more constituting the alkanediyl group The methylene group may be replaced with an oxygen atom or a carbonyl group.
R ⁴ and R ⁵ each independently represent a hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, One or more methylene groups constituting the group may be replaced with an oxygen atom or a carbonyl group.
Z ⁺ represents an organic cation. ]

Examples of the alkanediyl group of X ² include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. Hexane-1,6-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group, butane-1,3-diyl group, 2-methylpropane -1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group and the like.
Of these, a methylene group is preferable.

Examples of the group in which one or more methylene groups constituting the alkanediyl group are replaced with an oxygen atom or a carbonyl group include the following divalent groups. * Represents a bond with CF ₂ .

Examples of the group in which the hydrogen atom contained in the alkanediyl group is substituted with a hydroxy group or —OR ^{5 and} at least one methylene group constituting the alkanediyl group is replaced with an oxygen atom include the following groups. . * Represents a bond with CF ₂ .

The hydrocarbon group for R ⁴ and R ⁵ may be either saturated or unsaturated, for example, a linear or branched alkyl group or alkenyl group, a monocyclic or polycyclic alicyclic hydrocarbon group , Aromatic hydrocarbon groups and the like, and a combination of two or more of these groups may be used.
Examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.
Examples of the branched alkyl group include an isopropyl group, a sec-butyl group, and a tert-butyl group.
Examples of the linear or branched alkenyl group include a vinyl group and an α-methylvinyl group.
Examples of the monocyclic alicyclic hydrocarbon group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.
Examples of the polycyclic alicyclic hydrocarbon group include a norbornyl group and an adamantyl group.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, 2,6-diethylphenyl group, 2- And methyl-6-ethylphenyl.

［式（ＩＡ）中、Ｘ²及びＺ^＋は、上記と同じ意味を表す。
Ｒ⁶は、炭素数１〜１７の炭化水素基を表し、該炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよく、該炭化水素基を構成する１以上のメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。
Ｒ⁷は、炭素数１〜６のアルキル基を表す。
Ｒ⁸は、炭素数１〜６のフッ素化アルキル基を表す。
ただし、Ｒ⁶、Ｒ⁷及びＲ⁸の合計炭素数は、２０以下である。］ The acid generator (I) is preferably an acid generator represented by the formula (IA).

[In formula (IA), X ² and Z ⁺ represent the same meaning as described above.
R ⁶ represents a hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and one or more constituting the hydrocarbon group The methylene group may be replaced with an oxygen atom or a carbonyl group.
R ⁷ represents an alkyl group having 1 to 6 carbon atoms.
R ⁸ represents a fluorinated alkyl group having 1 to 6 carbon atoms.
However, the total carbon number of R ⁶ , R ⁷ and R ⁸ is 20 or less. ]

Ｒ⁷のアルキル基としては、メチル基、エチル基、プロピル基、ブチル基等が挙げられる。
Ｒ⁸のフッ素化アルキル基としては、トリフルオロメチル基、パーフルオロエチル基、１，１，２，２−テトラフルオロエチル基、パーフルオロブチル基、１，１，２，２，３，３，４，４−オクタフルオロブチル基等が挙げられ、好ましくはトリフルオロメチル基である。 Examples of the hydrocarbon group for R ⁶ include the same groups as those for R ⁴ , and an alicyclic hydrocarbon group is preferable.
Examples of the group in which one or more methylene groups constituting the hydrocarbon group are replaced with an oxygen atom or a carbonyl group include the following. * Represents a bond.

Examples of the alkyl group for R ⁷ include a methyl group, an ethyl group, a propyl group, and a butyl group.
As the fluorinated alkyl group for R ⁸ , a trifluoromethyl group, a perfluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, a perfluorobutyl group, 1,1,2,2,3,3, Examples include 4,4-octafluorobutyl group, and a trifluoromethyl group is preferable.

Examples of the acid generator (I) include the following salts.

Examples of Z ⁺ include organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, an arylsulfonium cation is more preferable, and a cation represented by any one of the formulas (b2-1) to (b2-4) [hereinafter, depending on the formula number Sometimes referred to as “cation (b2-1)”. ] Is more preferable.

In formula (b2-1) to formula (b2-4),
Each of R ^{b4 to} R ^b6 independently represents an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms; , R ^b4 and R ^b5 together form a ring containing a sulfur atom. The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group is substituted with a halogen atom, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5. When m2 is 2 or more, the plurality of R ^b7 are the same or different from each other, and when n2 is 2 or more, the plurality of R ^b8 are the same or different from each other.
R ^b9 and R ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or R ^b9 and R ^b10 are combined together. Together with the sulfur atom to which they are attached, forms a 3- to 12-membered ring (preferably a 3- to 7-membered ring). One or more —CH ₂ — constituting the ring may be replaced by —O—, —SO— or —CO—.
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group has 1 to 12 carbon atoms. Or an alkoxycarbonyloxy group having 1 to 12 carbon atoms.
R ^b11 and R ^b12 may form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) together with —CH—CO— to which they are bonded. One or more —CH ₂ — constituting the ring may be replaced by —O—, —SO— or —CO—.
R ^{b13 to} R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b24 represents -S- or -O-.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
y2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 are the same or different from each other. When p2 is 2 or more, the plurality of R ^b14 are the same or different from each other. When q2 is 2 or more, the plurality of R ^b15 are the same. Alternatively, when r2 is 2 or more, a plurality of R ^b16 are the same or different from each other, when s2 is 2 or more, a plurality of R ^b17 are the same or different from each other, and when t2 is 2 or more, a plurality of R ^{b16 b18} are the same or different from each other.

R ^b4 and R ^b5 may together form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) with the sulfur atom to which they are bonded.

特に、Ｒ^b9〜Ｒ^b11の脂環式炭化水素基は、好ましくは炭素数４〜１２である。 Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2- An ethylhexyl group is mentioned. In particular, the aliphatic hydrocarbon group represented by R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an alkyl group. In this case, the carbon number of the alicyclic hydrocarbon group is 20 or less including the carbon number of the alkyl group. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups.

In particular, the alicyclic hydrocarbon group of R ^{b9 to} R ^b11 preferably has 4 to 12 carbon atoms.

  Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an alkyl group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, a methylnorbornyl group, and an isobornyl group. Can be mentioned.

Examples of the aromatic hydrocarbon group include phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-adamantyl group. Substituted or unsubstituted phenyl groups such as phenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group; biphenylyl group, naphthyl group, phenanthryl group and the like.
As an aromatic hydrocarbon group by which the hydrogen atom was substituted by the alkoxy group, 4-methoxyphenyl group etc. are mentioned, for example.
Examples of the alkyl group in which a hydrogen atom is substituted with an aromatic hydrocarbon group, that is, an aralkyl group, include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.
In addition, when an alkyl group or an alicyclic hydrocarbon group is contained in an aromatic hydrocarbon group, a C1-C12 alkyl group and a C3-C18 alicyclic hydrocarbon group are preferable.

Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkylcarbonyloxy group include methylcarbonyloxy group, ethylcarbonyloxy group, n-propylcarbonyloxy group, isopropylcarbonyloxy group, n-butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group. Group, pentylcarbonyloxy group, hexylcarbonyloxy group, octylcarbonyloxy group, 2-ethylhexylcarbonyloxy group and the like.

The ring containing a sulfur atom which may be formed by combining R ^b4 and R ^b5 is any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. If it contains one or more sulfur atoms, it may further contain one or more sulfur atoms and / or one or more oxygen atoms. As the ring, a ring having 3 to 18 carbon atoms is preferable, and a ring having 4 to 18 carbon atoms is more preferable.

Examples of the ring formed together with the sulfur atom to which R ^b9 and R ^b10 are bonded include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium. A ring etc. are mentioned.
Examples of the ring formed with —CH—CO— in which R ^b11 and R ^b12 are bonded include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

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

Examples of the cation (b2-2) include the following cations.

Examples of the cation (b2-3) include the following cations.

  The acid generator (I) is a combination of the above anions and the above cations. These can be arbitrarily combined, and among them, the salt represented by the following is preferable.

［式中、Ｘ²、Ｒ⁴及びＺ^＋は、上記と同じ意味を表す。］ The acid generator (I) can be obtained, for example, by reacting a salt represented by the formula (I-0-1) with a compound represented by the formula (I-0-2) in a solvent. . Examples of the solvent include chloroform.

[Wherein, X ² , R ⁴ and Z ⁺ represent the same meaning as described above. ]

Examples of the salt represented by the formula (I-0-1) include salts represented by the following.

［式中、Ｒ⁴は、上記と同じ意味を表す。］
式（Ｉ−０−３）で表される化合物としては、例えば、以下で表される化合物等が挙げられる。

The compound represented by the formula (I-0-2) is obtained by reacting a salt represented by the formula (I-0-3) with a compound represented by the formula (I-0-4) in a solvent. Can be obtained.
Examples of the solvent include chloroform.

[Wherein R ⁴ represents the same meaning as described above. ]
Examples of the compound represented by the formula (I-0-3) include compounds represented by the following.

［式中、Ｘ²、Ｒ⁶、Ｒ⁷、Ｒ⁸及びＺ^＋は、上記と同じ意味を表す。］ The salt represented by the formula (IA) can be obtained, for example, by reacting the salt represented by the formula (IA-1) with the compound represented by the formula (IA-2) in a solvent. Examples of the solvent include chloroform.

[Wherein, X ² , R ⁶ , R ⁷ , R ⁸ and Z ⁺ represent the same meaning as described above. ]

［式中、Ｘ²、Ｒ⁷、Ｒ⁸及びＺ^＋は、上記と同じ意味を表す。］
式（ＩＡ−３）で表される塩は、例えば、以下で表される塩等が挙げられる。

式（ＩＡ−４）で表される化合物としては、トリフルオロピルビン酸エチル等が挙げられる。 The salt represented by the formula (IA-1) is obtained by reacting the salt represented by the formula (IA-3) and the compound represented by the formula (IA-4) in a solvent in the presence of an acid catalyst. Can be manufactured. Examples of the solvent include dimethylformamide. Examples of the acid catalyst include p-toluenesulfonic acid.

[Wherein, X ² , R ⁷ , R ⁸ and Z ⁺ represent the same meaning as described above. ]
Examples of the salt represented by the formula (IA-3) include salts represented by the following.

Examples of the compound represented by the formula (IA-4) include ethyl trifluoropyruvate.

［式中、Ｒ⁶は、上記と同じ意味を表す。］
式（ＩＡ−５）で表される化合物としては、例えば、以下で表される化合物等が挙げられる。

The compound represented by the formula (IA-2) can be obtained by reacting the salt represented by the formula (IA-5) and the compound represented by the formula (IA-6) in a solvent. .
Examples of the solvent include chloroform.

[Wherein R ⁶ represents the same meaning as described above. ]
Examples of the compound represented by the formula (IA-5) include compounds represented by the following.

  The acid generator (I) may be used alone or in combination of two or more.

［式（ＩＩ）中、
Ｒ^II3及びＲ^II4は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｘ^II1は、２価の炭素数１〜１７の飽和炭化水素基を表し、前記２価の飽和炭化水素基に含まれる水素原子は、フッ素原子で置換されていてもよく、前記２価の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いてもよい。
Ｒ^II5は、環状エーテル構造を含む基を表す。
Ｚ１^＋は、有機カチオンを表す。］
式（ＩＩ）において、正電荷を有する側を「有機カチオン」と、負電荷を有する側を「スルホン酸アニオン」と、それぞれ称することがある。
式（ＩＩ）におけるＲ^II3及びＲ^II4のペルフルオロアルキル基としては、例えば、トリフルオロメチル基、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、ペルフルオロヘキシル基などが挙げられる。
式（ＩＩ）においては、Ｒ^II3及びＲ^II4は、それぞれ独立に、好ましくはトリフルオロメチル基又はフッ素原子であり、より好ましくはフッ素原子である。 <Acid generator (II)>
The acid generator (II) includes a salt represented by the formula (II).

[In the formula (II),
R ^II3 and R ^II4 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
X ^II1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and the divalent saturated The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
R ^II5 represents a group containing a cyclic ether structure.
Z1 ⁺ represents an organic cation. ]
In the formula (II), a side having a positive charge may be referred to as an “organic cation”, and a side having a negative charge may be referred to as a “sulfonate anion”.
Examples of the perfluoroalkyl group represented by R ^II3 and R ^II4 in the formula (II) include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, and a perfluorotert-butyl group. Group, perfluoropentyl group, perfluorohexyl group and the like.
In the formula (II), R ^II3 and R ^II4 are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group of X ^II1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and these A combination of two or more of the groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
An alkyl group (particularly an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group); For example, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl A branched alkanediyl group such as a 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

Examples of the group in which the methylene group contained in the saturated hydrocarbon group of X ^II1 is replaced by an oxygen atom or a carbonyl group include divalent groups represented by formulas (b1-1) to (b1-6). It is done. The divalent group represented by the formula (b1-1) to the divalent group represented by the formula (b1-6) are described in accordance with the formula (II) on the left and right, and each is represented by *. is the coupling hands, the left ^{C (R II3) (R II4} ) - bound to, binds R ^II5 right. The same applies to specific examples of the divalent group represented by the following formula (b1-1) to the divalent group represented by the formula (b1-6).

式（ｂ１−１）〜式（ｂ１−６）中、
Ｌ^b2は、単結合又は炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２の２価の飽和炭化水素基を表す。
Ｌ^b4は、炭素数１〜１３の２価の飽和炭化水素基を表す。但しＬ^b3及びＬ^b4の炭素数上限は１３である。
Ｌ^b5は、炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b6及びＬ^b7は、それぞれ独立に、炭素数１〜１５の２価の飽和炭化水素基を表す。但しＬ^b6及びＬ^b7の炭素数上限は１６である。
Ｌ^b8は、炭素数１〜１４の２価の飽和炭化水素基を表す。
Ｌ^b9及びＬ^b10は、それぞれ独立に、炭素数１〜１１の２価の飽和炭化水素基を表す。但しＬ^b9及びＬ^b10の炭素数上限は１２である。

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

Among them, X ¹ is preferably any one of groups represented by formula (b1-1) to formula (b1-4), more preferably represented by formula (b1-1) or formula (b1-2). Group, more preferably a divalent group represented by formula (b1-1). In particular, a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond or —CH ₂ — is preferable.

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

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

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

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

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

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

^Examples of the group containing a cyclic ether structure of R ^II5 include a group containing a monocyclic or polycyclic cyclic ether structure. The group containing a cyclic ether structure may have a substituent. In the case of the monocyclic cyclic ether structure and the polycyclic cyclic ether structure, the ring structure containing an oxygen atom suitably has, for example, 2 to 5 carbon atoms.

［式（ＩＩＡ）及び式（ＩＩＥ）中、
ｓ１は、１〜４の整数を表す。ｔ１は、０〜２の整数を表す。但し、ｓ１＋ｔ１は、１〜４である。
ｓ１１は、１〜４の整数を表す。ｔ１１は、０〜２の整数を表す。
ｓ１２は、１〜４の整数を表す。ｔ１２は、０〜２の整数を表す。但し、ｓ１２＋ｔ１２は、０〜４である。
Ｒ^II6は、炭素数１〜１２の飽和炭化水素基又は炭素数６〜１８の芳香族炭化水素基を表し、前記飽和炭化水素基及び前記芳香族炭化水素基に含まれる水素原子は、炭素数１〜６のアルキル基又はニトロ基で置換されていてもよく、Ｒ^II6の２つが互いに結合して環を形成してもよく、前記飽和炭化水素基及び環に含まれる−ＣＨ₂−は、−Ｏ−で置き換わっていてもよい。
ｕ１は、０〜８の整数を表し、ｕ１が２以上である場合、複数のＲ^II6は同一又は相異なる。
Ｒ^II7及びＲ^II8は、それぞれ独立に、ヒドロキシ基、ハロゲン基、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１〜６のヒドロキシアルキル基、炭素数２〜７のアシル基、炭素数２〜７のアシルオキシ基又は炭素数２〜７のアシルアミノ基を表し、Ｒ^II7及びＲ^II8の２つが互いに結合して単結合又は環を形成してもよい。
ｕ２及びｕ３は、それぞれ独立に、０〜１６の整数を表し、ｕ２が２以上である場合、複数のＲ^II7は同一又は相異なり、ｕ３が２以上である場合、複数のＲ^II8は同一又は相異なる。
＊はＸ¹との結合手である。］ Examples of the group containing a cyclic ether structure include a group represented by the formula (IIA) and a group represented by the formula (IIE).

[In Formula (IIA) and Formula (IIE),
s1 represents an integer of 1 to 4. t1 represents the integer of 0-2. However, s1 + t1 is 1-4.
s11 represents an integer of 1 to 4. t11 represents an integer of 0 to 2.
s12 represents an integer of 1 to 4. t12 represents an integer of 0 to 2. However, s12 + t12 is 0-4.
R ^II6 represents a saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group and the aromatic hydrocarbon group has a carbon number 1 to 6 alkyl groups or nitro groups may be substituted, and two of R ^II6 may be bonded to each other to form a ring, and —CH ₂ — contained in the saturated hydrocarbon group and the ring is It may be replaced by -O-.
u1 represents an integer of 0 to 8, and when u1 is 2 or more, the plurality of R ^II6 are the same or different.
R ^II7 and R ^II8 are each independently a hydroxy group, a halogen group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, 2 to 7 carbon atoms acyl group, represents an acyloxy group, or an acylamino group having 2 to 7 carbon atoms having 2 to 7 carbon atoms, may form a two but a single bond or a ring bonded to each other of R ^II7 and R ^II8.
u2 and u3 are independently an integer of 0 to 16, if u2 is 2 or more, the plurality of R ^II7 same or different, when u3 is 2 or more, plural R ^II8 are the same or Different.
* Represents a bond to X ^1. ]

なかでも、シクロアルキル基、シクロヘキシル基、アダマンチル基等が好ましい。
芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ｐ−メチルフェニル基、ｐ−ｔｅｒｔ−ブチルフェニル基、ｐ−アダマンチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、ビフェニル基、フェナントリル基、２，６−ジエチルフェニル基、２−メチル−６−エチルフェニル等のアリール基等が挙げられる。
Ｒ⁶の２つが互いに結合して環を形成する場合、この環は、不飽和及び飽和の環のいずれであってもよい。また、環を形成するＲ⁶は、異なる炭素原子に結合する２つのＲ⁶であってもよいし、同じ炭素原子に結合する２つのＲ⁶であってもよい。 In the formula (IIA) and the formula (IIE), ^examples of the saturated hydrocarbon group for R ^II6 include alkyl groups, monocyclic and polycyclic cyclic hydrocarbon groups (including spiro ring groups and the like).
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
Examples of the cyclic hydrocarbon group include monocyclic cyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, and cyclooctyl group. It is done. Examples of the polycyclic cyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, a methylnorbornyl group, and the following groups.

Of these, a cycloalkyl group, a cyclohexyl group, an adamantyl group and the like are preferable.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
When two of R ⁶ are bonded to each other to form a ring, this ring may be either an unsaturated ring or a saturated ring. Further, R ⁶ forming the ring may be two R ⁶ bonded to different carbon atoms, or may be two R ⁶ bonded to the same carbon atom.

The alkyl group of R ^II7 and R ^II8, include the same as exemplified for R ^II6.
Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentoxy group, n-hexoxy group and the like.
Examples of the hydroxyalkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
Examples of the acylamino group include an acetylamino group, a propionylamino group, and a butyrylamino group.
When forming a single bond bonded to each other at R ^II7 and R ^II8, among others, it is preferred that two R ^II8 are combined to form a single bond together.
s1 is preferably 1, t1 is preferably 0 or 1, and s1 + t1 is preferably 1 or 2.
s12 + t12 is preferably 1 or 2.

Examples of the group represented by the formula (IIA) include the following groups.

Examples of the group represented by the formula (IIE) include the following groups.

Specific examples of the group represented by the formula (IIA) include the following groups.

Specific examples of the group represented by the formula (IIE) include the following groups.

R ^II5 in the formula (II) preferably includes a cyclic ether structure having 2 to 5 carbon atoms. Specifically, a structure containing an oxirane ring, a structure containing an oxetane ring, a structure containing a 5-membered ring ether structure having 4 carbon atoms (tetrahydrofuran ring), and a 6-membered ring ether structure having 5 carbon atoms (tetrahydropyran ring) are included. Examples include the structure. Among them, a cyclic ether structure having 2 or 3 carbon atoms is preferable, and for example, a 3-membered cyclic ether structure having 2 carbon atoms (oxirane ring) or a 4-membered ether structure having 3 carbon atoms (oxetane ring) is preferable. The 3-membered ether structure (oxirane ring) is more preferable.

［式中、すべての符号は上記と同義である。］ The acid generator represented by the formula (II) is preferably, for example, an acid generator represented by the formula (II-a) or an acid generator represented by the formula (II-b). It is more preferable that it is an acid generator represented by II-a).

[Wherein all symbols are as defined above. ]

Examples of the acid generator represented by the formula (II) include the following salts.

Examples of Z1 ⁺ include organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an arylsulfonium cation is more preferable.

Z1 ⁺ is preferably a cation represented by any one of the formulas (b2-1) to (b2-4) described above.

The acid generator represented by the formula (II) is a combination of the above-mentioned anions and cations. Although the above-mentioned anion and cation can be combined arbitrarily, the salt represented below is preferable.

The acid generator represented by the formula (II) can be produced by the following methods (1) to (3) or a method analogous thereto. In addition, the definition of the substituent in the following formulas has the same meaning as described above unless otherwise specified.
(1) The acid generator represented by the formula (IIa) in which ^XII1 is a group (—CO—O—L ^b2 —) represented by the formula (b1-1) is represented by the formula (II-1). It can obtain by making the salt and the compound represented by Formula (II-2) react in a solvent. Examples of the solvent include acetonitrile.

式（ＩＩＡ−２）で表される化合物としては、グリシドール、２−ヒドロキシメチルオキセタン、３−エチル−３−オキセタンメタノールなどが挙げられる。
式（ＩＩ−１）で表される塩は、式（ＩＩＡ−３）で表される塩と式（ＩＩＡ−４）で表される化合物（カルボニルジイミダゾール）とを溶剤中で反応させることにより製造することができる。溶剤としては、アセトニトリル等が挙げられる。
式（ＩＩＡ−３）で表される塩は、特開２００８−１２７３６７号公報に記載された方法で合成することができる。

(2) The acid generator represented by the formula (II-aa) in which X ^II1 is a group (—CO—O—L ^b2 —) represented by the formula (b1-1) is represented by the formula (II- It can be obtained by reacting the salt represented by 1) with the compound represented by the formula (IIA-2) in a solvent. Examples of the solvent include acetonitrile.

Examples of the compound represented by the formula (IIA-2) include glycidol, 2-hydroxymethyloxetane, and 3-ethyl-3-oxetanemethanol.
The salt represented by the formula (II-1) is obtained by reacting the salt represented by the formula (IIA-3) and the compound (carbonyldiimidazole) represented by the formula (IIA-4) in a solvent. Can be manufactured. Examples of the solvent include acetonitrile.
The salt represented by the formula (IIA-3) can be synthesized by the method described in JP-A-2008-127367.

式（ＩＩＢ−１）で表される塩は、例えば、式（ＩＩＢ−２ａ）で表される塩と式（ＩＩＡ−４）で表される化合物（カルボニルジイミダゾール）とを溶剤中で反応させることにより製造することができる。溶剤としては、アセトニトリル等が挙げられる。 (3) X ^II1 has the formula (b1-2) a group represented by ^{(-CO-O-L b4 -CO} -O-L b3 -) salt represented by a is Formula (II-a-b) is The salt represented by the formula (IIB-1) and the compound represented by the formula (IIB-2) can be reacted in a solvent. Examples of the solvent include acetonitrile.

The salt represented by the formula (IIB-1) is obtained by, for example, reacting a salt represented by the formula (IIB-2a) with a compound (carbonyldiimidazole) represented by the formula (IIA-4) in a solvent. Can be manufactured. Examples of the solvent include acetonitrile.

式（ＩＩＢ−４）で表される塩は、特開２００８−１２７３６７号公報に記載された方法で合成することができる。
式（ＩＩＢ−５）で表される化合物としては、ブロモ酢酸等が挙げられる。 The salt represented by the formula (IIB-2) can be obtained by reacting the salt represented by the formula (IIB-4) with the compound represented by the formula (IIB-5) in the presence of a catalyst. Here, examples of the catalyst include potassium iodide and potassium carbonate. This reaction may be carried out in a solvent. Examples of the solvent include dimethylformamide.

The salt represented by the formula (IIB-4) can be synthesized by the method described in JP-A-2008-127367.
Examples of the compound represented by the formula (IIB-5) include bromoacetic acid.

  The acid generator represented by the formula (II) may be used alone or in combination of two or more.

<Acid generator other than acid generator (I) and acid generator (II)>
The resist composition used in the production method of the present invention contains an acid generator other than the acid generator (I) and the acid generator (II) described above (hereinafter sometimes referred to as “acid generator (B)”). It may be.
The acid generator (B) may be either nonionic or ionic. 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), 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.

  The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as “salt (B1)”).

［式（Ｂ１）中、
Ｑ^b1及びＱ^b2は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１〜２４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、フッ素原子又はヒドロキシ基に置き換わっていてもよく、該飽和炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、水素原子、フッ素原子、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を表し、該脂環式炭化水素基を構成するメチレン基は、酸素原子、スルホニル基又はカルボニル基に置き換わっていてもよい。
Ｚ_ｂ ⁺は、有機カチオンを表す。］

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a saturated hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, and methylene constituting the saturated hydrocarbon group The group may be replaced by an oxygen atom or a carbonyl group.
Y represents a hydrogen atom, a fluorine atom, or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, A sulfonyl group or a carbonyl group may be substituted.
Z _b ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group for Q ^b1 and Q ^b2 include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, A perfluorohexyl group etc. are mentioned.
Q ^b1 and Q ^b2 are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the saturated hydrocarbon group for L ^b1 include an aliphatic saturated hydrocarbon group such as a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic alicyclic saturated hydrocarbon group, A combination of two or more of these groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
Butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4- Branched alkanediyl groups such as diyl groups;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

Examples of the group in which one or more methylene groups constituting the saturated hydrocarbon group of L ^b1 are replaced by an oxygen atom or a carbonyl group include those represented by any of formulas (b1′-1) to (b1′-7). Group to be used. L ^b1 is preferably a group represented by any one of formulas (b1′-1) to (b1′-4), more preferably represented by formula (b1′-1) or formula (b1′-2). Group to be used. In addition, Formula (b1'-1)-Formula (b1'-7) has described the right and left according to Formula (B1), and it is C on the left side among the two bonds represented by *, respectively. It binds to (Q ^b1 ) (Q ^b2 ) — and on the right side to —Y. The same applies to specific examples of the following formulas (b1′-1) to (b1′-7).

式（ｂ１’−１）〜式（ｂ１’−７）中、
Ｌ^b2'は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表す。
Ｌ^b3'は、単結合又は炭素数１〜１９の２価の飽和炭化水素基を表す。
Ｌ^b4'は、炭素数１〜２０の２価の飽和炭化水素基を表す。但しＬ^b3'及びＬ^b4'の炭素数上限は２０である。
Ｌ^b5'は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表す。
Ｌ^b6'は、炭素数１〜２２の２価の飽和炭化水素基を表す。但しＬ^b5'及びＬ^b6'の合計炭素数上限は２２である。
Ｌ^b7'は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表す。
Ｌ^b8'は、炭素数１〜２３の２価の飽和炭化水素基を表す。但しＬ^b7'及びＬ^b8'の合計炭素数上限は２３である。
Ｌ^b9'は、単結合又は炭素数１〜１９の２価の飽和炭化水素基を表す。
Ｌ^b10'は、炭素数１〜２１の２価の飽和炭化水素基を表す。但しＬ^b9'及びＬ^b10'の合計炭素数の上限は２１である。
Ｌ^b11'及びＬ^b12'は、単結合又は炭素数１〜１８の２価の飽和炭化水素基を表す。
Ｌ^b13'は、炭素数１〜１９の２価の飽和炭化水素基を表す。但しＬ^b11'、Ｌ^b12'及びＬ^b13'の合計炭素数の上限は１９である。
Ｌ^b14'及びＬ^b15'は、それぞれ独立に、単結合又は炭素数１〜２０の２価の飽和炭化水素基を表す。
Ｌ^b16'は、炭素数１〜２１の２価の飽和炭化水素基を表す。但しＬ^b14'、Ｌ^b15'及びＬ^b16'の合計炭素数の上限は２１である。

In formula (b1′-1) to formula (b1′-7),
L ^{b2 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms.
L ^{b3 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^{b4 ′} represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms. However, the upper limit of the carbon number of L ^{b3 ′} and L ^{b4 ′} is 20.
L ^{b5 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms.
L ^{b6 ′} represents a divalent saturated hydrocarbon group having 1 to 22 carbon atoms. However, the upper limit of the total carbon number of L ^{b5 ′} and L ^{b6 ′} is 22.
L ^{b7 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms.
L ^{b8 ′} represents a divalent saturated hydrocarbon group having 1 to 23 carbon atoms. However, the upper limit of the total carbon number of L ^{b7 ′} and L ^{b8 ′} is 23.
L ^{b9 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^{b10 ′} represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. However, the upper limit of the total carbon number of L ^{b9 ′} and L ^{b10 ′} is 21.
L ^{b11 ′} and L ^{b12 ′} represent a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^{b13 ′} represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms. However, the upper limit of the total carbon number of L ^{b11 ′} , L ^{b12 ′} and L ^{b13 ′} is 19.
L ^{b14 ′} and L ^{b15 ′} each independently represent a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms.
L ^{b16 ′} represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. However, the upper limit of the total carbon number of L ^{b14 ′} , L ^{b15 ′} and L ^{b16 ′} is 21.

Among them, L ^b1 is preferably any one of the formulas (b1′-1) to (b1′-4), more preferably the formula (b1′-1) or the formula (b1′-2), and more preferably the formula A divalent group represented by (b1′-1), particularly preferably a divalent group represented by the formula (b1′-1) in which L ^{b2 ′} is a single bond or —CH ₂ —. is there.

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

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

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

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

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

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

Examples of the divalent group represented by the formula (b1′-7) include the following.

Specific examples when the hydrogen atom contained in the saturated hydrocarbon group of L ^b1 is substituted with a fluorine atom or a hydroxy group include the following.

Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y26).

  Especially, it is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

Examples of the substituent for the alicyclic hydrocarbon group in Y include a halogen atom, a hydroxy group, an oxo group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and 3 to 3 carbon atoms. 16 alicyclic hydrocarbon groups, alkoxy groups having 1 to 12 carbon atoms, aromatic hydrocarbon groups having 6 to 18 carbon atoms, aralkyl groups having 7 to 21 carbon atoms, acyl groups having 2 to 4 carbon atoms, glycidyloxy Group or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or 6 to 6 carbon atoms). 18 represents an aromatic hydrocarbon group, and j2 represents an integer of 0 to 4.

Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group, mesityl group. , Aryl groups such as biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.

Examples of Y include the following.

  Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, more preferably a substituent (for example, an oxo group, a hydroxy group, etc.). A good adamantyl group, more preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

The sulfonate anion in the salt (B1) is preferably an anion represented by the formula (b1-1-1) to the formula (b1-1-9). In the following formulas, the definitions of the symbols have the same meaning as described above, and R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group).
Specific examples of the sulfonate anion in the salt (B1) include anions described in JP 2010-204646 A.

Examples of the organic cation (Z _b ⁺ ) contained in the salt (B1) include organic onium cations such as organic sulfonium cation, organic iodonium cation, organic ammonium cation, benzothiazolium cation, and organic phosphonium cation. , An organic sulfonium cation or an organic iodonium cation, more preferably an arylsulfonium cation, and still more preferably the same as the cation represented by any one of the formulas (b2-1) to (b2-4) described above. belongs to.

  Examples of the salt (B1) include salts represented by formulas (B1-1) to (B1-20), respectively. Among them, those containing an arylsulfonium cation are preferable. Formula (B1-1), Formula (B1-2), Formula (B1-3), Formula (B1-6), Formula (B1-7), Formula (B1-11) ), Formula (B1-12), Formula (B1-13), Formula (B1-14), Formula (B1-18), Formula (B1-19), or Formula (B1-20). More preferred are salts.

  The acid generator (B) may be used alone or in combination of two or more.

When the resist composition contains the acid generator (I) and the acid generator (II), the total content of the acid generator (I) and the acid generator (II) is 100 masses of the resin (A). The amount is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 40 parts by mass or less (more preferably 35 parts by mass or less). In this case, the content ratio (mass ratio) of the acid generator (I) and the acid generator (II) is, for example, 5:95 to 95: 5, preferably 10:90 to 90:10, and more preferably 15 : 85-85: 15.
When the resist composition contains an acid generator (I), an acid generator (II), and an acid generator (B), the acid generator (I), the acid generator (II), and the acid generator (B ) With respect to 100 parts by mass of the resin (A), preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 40 parts by mass or less (more preferably 35 parts by mass or less). It is.
The ratio (mass ratio) of the total content of the acid generator (I) and the acid generator (II) and the content of the acid generator (B) is, for example, 5:95 to 95: 5, Preferably it is 10: 90-90: 10, More preferably, it is 15: 85-85: 15.

<Solvent (E)>
The content of the solvent (E) is, for example, 90% by mass or more in the resist composition, preferably 92% by mass or more, more preferably 94% by mass or more, for example 99.9% by mass or less, preferably 99% by mass or less. It is. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

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

<Basic compound (C)>
The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by any one of the formulas (C1) to (C8) and (C1-1), more preferably represented by the formula (C1-1). The compound which is made is mentioned.

［式（Ｃ１）中、Ｒ^c1、Ｒ^c2及びＲ^c3は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基、炭素数５〜１０の脂環式炭化水素基又は炭素数６〜１０の芳香族炭化水素基を表し、該アルキル基及び該脂環式炭化水素基に含まれる水素原子は、ヒドロキシ基、アミノ基又は炭素数１〜６のアルコキシ基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。］

[In formula (C1), R ^c1 , R ^c2 and R ^c3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or 6 to 6 carbon atoms. 10 represents an aromatic hydrocarbon group, and 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, The hydrogen atom contained in the aromatic hydrocarbon group is 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 group having 6 to 10 carbon atoms. It may be substituted with a group hydrocarbon group. ]

［式（Ｃ１−１）中、Ｒ^c2及びＲ^c3は、上記と同じ意味を表す。
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は互いに同一又は相異なる。］

[In Formula (C1-1), R ^c2 and R ^c3 represent the same meaning as described 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, the plurality of R ^c4 are the same 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、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c9は、炭素数１〜６のアルキル基、炭素数３〜６の脂環式炭化水素基又は炭素数２〜６のアルカノイル基を表す。
ｎ３は０〜８の整数を表し、ｎ３が２以上のとき、複数のＲ^c9は互いに同一又は相異なる。］

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

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

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

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

Wherein (C7) and formula ^{(C8), R c18, R} c19 and R ^c20 in each occurrence independently represent the same meaning as R ^c4.
q3, r3 and s3 each independently represent an integer of 0 to 3, and when q3 is 2 or more, the plurality of R ^c18 are the same or different from each other, and when r3 is 2 or more, the plurality of R ^c19 are When the same or different from each other and s3 is 2 or more, the plurality of R ^c20 are the same or different from each other.
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. ]

In formula (C1) to formula (C8) and formula (C1-1), the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, alkoxy group, alkanediyl group are the same as those described above. Is mentioned.
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.

  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, 4,4′-diamino-3,3′-diethyldiphenylmethane, and preferably diisopropyl. Piruanirin. 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.

  The content of the basic compound (C) is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass, and particularly preferably in the solid content of the resist composition. It is about 0.01-1 mass%.

<Other components (hereinafter sometimes referred to as “other components (F)”)>
The resist composition may contain other components (F) as necessary. The other component (F) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes and the like can be used.

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

<Application>
The method for producing a resist pattern of the present invention includes a method for producing a resist pattern by KrF excimer laser exposure, ArF excimer laser exposure, electron beam (EB) exposure or EUV exposure, and a method for producing a resist pattern by immersion exposure, particularly a liquid. It is suitable as a method for producing a resist pattern for immersion ArF excimer laser exposure, and is useful for fine processing of semiconductors.

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 structure of the compound was confirmed by MASS (LC: Agilent 1100 type, MASS: Agilent LC / MSD type or LC / MSD TOF type).
The weight average molecular weight is a value determined by gel permeation chromatography under the following conditions.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore HXL-M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

式（Ｉ１−ａ）で表される塩を、特開２００８−７４０９号公報に記載された方法で合成した。式（Ｉ１−ａ）で表される塩１０．００部、ジメチルホルミアミド５０．００部、式（Ｉ１−ｂ）で表される化合物４．１８部及びｐ−トルエンスルホン酸０．７０部を仕込み、１００℃で２時間攪拌した。得られた反応液に、クロロホルム２００部及びイオン交換水５０部を仕込み、３０分間攪拌し、分液した。この水洗操作を３回繰り返した。回収された有機層を濃縮し、濃縮物をカラム（メルク シリカゲル６０−２００メッシュ 展開溶媒：クロロホルム／メタノール＝５／１）分取することにより、式（Ｉ１−ｃ）で表される塩２．４３部を得た。 Synthesis Example 1: [Synthesis of salt represented by formula (I-1)]

The salt represented by the formula (I1-a) was synthesized by the method described in JP-A-2008-7409. 10.00 parts of salt represented by formula (I1-a), 50.00 parts of dimethylformamide, 4.18 parts of compound represented by formula (I1-b) and 0.70 parts of p-toluenesulfonic acid And stirred at 100 ° C. for 2 hours. To the obtained reaction solution, 200 parts of chloroform and 50 parts of ion-exchanged water were added, stirred for 30 minutes, and separated. This washing operation was repeated three times. The collected organic layer is concentrated, and the concentrate is fractionated in a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to give a salt represented by the formula (I1-c) 2. 43 parts were obtained.

式（Ｉ１−ｄ）で表される化合物０．６３部及びクロロホルム１０部を仕込み、２３℃で３０分間攪拌し、式（Ｉ１−ｅ）で表される化合物０．５５部を仕込み、６０℃で１時間攪拌した。得られた反応物を２３℃まで冷却し、ろ過することにより、式（Ｉ１−ｆ）で表される化合物を含む溶液を得た。式（Ｉ１−ｆ）で表される化合物を含む溶液に、式（Ｉ１−ｃ）で表される塩２．１０部を仕込み、６０℃で６時間攪拌した。得られた反応物に、クロロホルム５０部及びイオン交換水２０部を仕込み、攪拌、分液を行った。水洗を５回行った。得られた有機層を濃縮し、得られた濃縮物をアセトニトリル２０部に溶解し、濃縮した。得られた濃縮物に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ−１）で表される塩１．６９部を得た。

0.63 part of a compound represented by the formula (I1-d) and 10 parts of chloroform were charged, stirred at 23 ° C. for 30 minutes, 0.55 part of a compound represented by the formula (I1-e) was charged, and 60 ° C. For 1 hour. The obtained reaction product was cooled to 23 ° C. and filtered to obtain a solution containing a compound represented by the formula (I1-f). A solution containing the compound represented by the formula (I1-f) was charged with 2.10 parts of the salt represented by the formula (I1-c) and stirred at 60 ° C. for 6 hours. To the obtained reaction product, 50 parts of chloroform and 20 parts of ion-exchanged water were charged, stirred and separated. Water washing was performed 5 times. The obtained organic layer was concentrated, and the resulting concentrate was dissolved in 20 parts of acetonitrile and concentrated. To the obtained concentrate, 30 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 1.69 parts of the salt represented by the formula (I-1).

MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 573.1

式（ＩＩ−１−ａ）で表される塩を、特開２００８−１２７３６７号公報に記載された方法で合成した。式（ＩＩ−１−ａ）で表される塩１０．００部、アセトニトリル５０部、式（ＩＩ−１−ｂ）で表される化合物（商品名：カルボニルジイミダゾール 東京化成製）４．４４部を仕込み、８０℃で３０分間攪拌した。その後、得られた反応物を２３℃まで冷却し、ろ過して、式（ＩＩ−１−ｃ）で表される塩を含有する溶液５９．４８部を得た。 Synthesis Example 2: [Synthesis of salt represented by formula (II-1)]

A salt represented by the formula (II-1-a) was synthesized by the method described in JP-A-2008-127367. 10.00 parts of salt represented by formula (II-1-a), 50 parts of acetonitrile, compound represented by formula (II-1-b) (trade name: carbonyldiimidazole manufactured by Tokyo Chemical Industry Co., Ltd.) 4.44 parts And stirred at 80 ° C. for 30 minutes. Thereafter, the obtained reaction product was cooled to 23 ° C. and filtered to obtain 59.48 parts of a solution containing a salt represented by the formula (II-1-c).

式（ＩＩ−１−ｃ）で表される塩を含有する溶液５９．４８部、式（ＩＩ−１−ｄ）で表される化合物（商品名：３−エチル−オキセタンメタノール 東京化成製）２．５７部を仕込み、２３℃で１時間攪拌し、ろ過した。回収された濾液を濃縮し、得られた濃縮物に、クロロホルム１００部及びイオン交換水３０部を仕込み、３０分間攪拌し、分液した。この水洗操作を３回繰り返した。回収された有機層を濃縮することにより、式（ＩＩ−１）で表される塩８．７３部を得た。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ２７３．０

59.48 parts of a solution containing a salt represented by the formula (II-1-c), a compound represented by the formula (II-1-d) (trade name: 3-ethyl-oxetanemethanol manufactured by Tokyo Chemical Industry Co., Ltd.) 2 .57 parts was charged, stirred at 23 ° C. for 1 hour, and filtered. The collected filtrate was concentrated, and 100 parts of chloroform and 30 parts of ion-exchanged water were added to the resulting concentrate, followed by stirring for 30 minutes and liquid separation. This washing operation was repeated three times. The recovered organic layer was concentrated to obtain 8.73 parts of the salt represented by the formula (II-1).
MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 273.0

式（ＩＩ−２−ａ）で表される塩１０．９６部、アセトニトリル５０部、式（ＩＩ−２−ｂ）で表される化合物（商品名：カルボニルジイミダゾール 東京化成製）４．４４部を仕込み、８０℃で３０分間攪拌した。得られた反応物を２３℃まで冷却し、ろ過して、式（ＩＩ−２−ｃ）で表される塩を含有する溶液６０．５４部を得た。 Synthesis Example 3: [Synthesis of salt represented by formula (II-2)]

10.96 parts of a salt represented by the formula (II-2-a), 50 parts of acetonitrile, a compound represented by the formula (II-2-b) (trade name: carbonyldiimidazole, manufactured by Tokyo Chemical Industry) 4.44 parts And stirred at 80 ° C. for 30 minutes. The obtained reaction product was cooled to 23 ° C. and filtered to obtain 60.54 parts of a solution containing a salt represented by the formula (II-2-c).

式（ＩＩ−２−ｃ）で表される塩を含有する溶液６０．５４部、式（ＩＩ−２−ｄ）で表される化合物（商品名：３−エチル−オキセタンメタノール 東京化成製）２．５７部を仕込み、２３℃で１時間攪拌し、ろ過した。回収された濾液を濃縮し、得られた濃縮物に、クロロホルム１００部及びイオン交換水３０部を仕込み、３０分間攪拌し、分液した。この水洗操作を３回繰り返した。回収された有機層を濃縮することにより、式（ＩＩ−２）で表される塩８．９２部を得た。

60.54 parts of a solution containing a salt represented by the formula (II-2-c), a compound represented by the formula (II-2-d) (trade name: 3-ethyl-oxetanemethanol manufactured by Tokyo Chemical Industry Co., Ltd.) 2 .57 parts was charged, stirred at 23 ° C. for 1 hour, and filtered. The collected filtrate was concentrated, and 100 parts of chloroform and 30 parts of ion-exchanged water were added to the resulting concentrate, followed by stirring for 30 minutes and liquid separation. This washing operation was repeated three times. The recovered organic layer was concentrated to obtain 8.92 parts of the salt represented by the formula (II-2).

MS (ESI (+) Spectrum): M ⁺ 305.1
MS (ESI (-) Spectrum): M ^- 273.0

式（ＩＩ−３−ａ）で表される塩を、特開２００８−１２７３６７号公報に記載された方法で合成した。式（ＩＩ−３−ａ）で表される塩１０．００部、アセトニトリル５０．００部、式（ＩＩ−３−ｂ）で表される化合物（商品名：カルボニルジイミダゾール 東京化成製）４．４４部を仕込み、８０℃で３０分間攪拌した後、得られた反応物を２３℃まで冷却し、ろ過して、式（ＩＩ−３−ｃ）で表される塩を含有する溶液５９．６８部を得た。 Synthesis Example 4: [Synthesis of salt represented by formula (II-3)]

A salt represented by the formula (II-3-a) was synthesized by a method described in JP-A-2008-127367. 3. 10.00 parts of salt represented by formula (II-3-a), 50.00 parts of acetonitrile, compound represented by formula (II-3-b) (trade name: carbonyldiimidazole manufactured by Tokyo Chemical Industry Co., Ltd.) After charging 44 parts and stirring at 80 ° C. for 30 minutes, the resulting reaction product was cooled to 23 ° C., filtered, and a solution 59.68 containing a salt represented by the formula (II-3-c). Got a part.

式（ＩＩ−３−ｃ）で表される塩を含有する溶液５９．６８部、式（ＩＩ−３−ｄ）で表される化合物（商品名：グリシドール アルドリッチ製）１．６４部を仕込み、２３℃で１時間攪拌し、ろ過した。回収された濾液を濃縮し、得られた濃縮物に、クロロホルム１００部及びイオン交換水３０部を仕込み、３０分間攪拌し、分液した。この水洗操作を３回繰り返した。回収された有機層を濃縮することにより、式（ＩＩ−３）で表される塩５．８０部を得た。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ２３１．０

59.68 parts of a solution containing a salt represented by the formula (II-3-c), 1.64 parts of a compound represented by the formula (II-3-d) (trade name: manufactured by Glicidol Aldrich), The mixture was stirred at 23 ° C. for 1 hour and filtered. The collected filtrate was concentrated, and 100 parts of chloroform and 30 parts of ion-exchanged water were added to the resulting concentrate, followed by stirring for 30 minutes and liquid separation. This washing operation was repeated three times. The recovered organic layer was concentrated to obtain 5.80 parts of the salt represented by the formula (II-3).
MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 231.0

式（ＩＩ−４−ａ）で表される塩を、特開２００８−１２７３６７号公報に記載された方法で合成した。式（ＩＩ−４−ａ）で表される塩１０．００部、アセトニトリル５０．００部、式（ＩＩ−４−ｂ）で表される化合物（商品名：カルボニルジイミダゾール 東京化成製）４．４４部を仕込み、８０℃で３０分間攪拌した。得られた反応物を２３℃まで冷却し、ろ過して、式（ＩＩ−４−ｃ）で表される塩を含有する溶液５９．８８部を得た。 Synthesis Example 5: [Synthesis of salt represented by formula (II-4)]

A salt represented by the formula (II-4-a) was synthesized by the method described in JP-A-2008-127367. 3. 10.00 parts of salt represented by formula (II-4-a), 50.00 parts of acetonitrile, compound represented by formula (II-4-b) (trade name: carbonyldiimidazole manufactured by Tokyo Chemical Industry Co., Ltd.) 44 parts were charged and stirred at 80 ° C. for 30 minutes. The obtained reaction product was cooled to 23 ° C. and filtered to obtain 59.88 parts of a solution containing a salt represented by the formula (II-4-c).

式（ＩＩ−４−ｃ）で表される塩を含有する溶液５９．８８部、式（ＩＩ−４−ｄ）で表される化合物（商品名：５，５−ジメチル−７−オキサビシクロ［４．１．０］ペンタン−２−オール アルドリッチ製）３．１５部を仕込み、２３℃で１時間攪拌し、ろ過した。回収された濾液を濃縮し、得られた濃縮物に、クロロホルム１００部及びイオン交換水３０部を仕込み、３０分間攪拌し、分液した。この水洗操作を３回繰り返した。回収された有機層を濃縮することにより、式（ＩＩ−４）で表される塩５．４２部を得た。

59.88 parts of a solution containing a salt represented by the formula (II-4-c), a compound represented by the formula (II-4-d) (trade name: 5,5-dimethyl-7-oxabicyclo [ 4.1.0] Pentan-2-ol (manufactured by Aldrich) was charged, stirred at 23 ° C. for 1 hour, and filtered. The collected filtrate was concentrated, and 100 parts of chloroform and 30 parts of ion-exchanged water were added to the resulting concentrate, followed by stirring for 30 minutes and liquid separation. This washing operation was repeated three times. The recovered organic layer was concentrated to obtain 5.42 parts of the salt represented by the formula (II-4).

MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 299.0

式（Ｂ１−５−ａ）で表される塩５０．４９部及びクロロホルム２５２．４４部を反応器に仕込み、２３℃で３０分間攪拌した後、式（Ｂ１−５−ｂ）で表される化合物１６．２７部を滴下し、２３℃で１時間攪拌することにより、式（Ｂ１−５−ｃ）で表される塩を含む溶液を得た。得られた式（Ｂ１−５−ｃ）で表される塩を含む溶液に、式（Ｂ１−５−ｄ）で表される塩４８．８０部及びイオン交換水８４．１５部を添加し、２３℃で１２時間攪拌した。得られた反応液が２層に分離していたので、クロロホルム層を分液して取り出し、更に、該クロロホルム層にイオン交換水８４．１５部を添加し、水洗した。この操作を５回繰り返した。得られたクロロホルム層に、活性炭３．８８部を添加攪拌した後、ろ過した。回収されたろ液を濃縮し、得られた残渣に、アセトニトリル１２５．８７部を添加攪拌後、濃縮した。得られた残渣に、アセトニトリル２０．６２部及びｔｅｒｔ−ブチルメチルエーテル３０９．３０部を加えて２３℃で３０分間攪拌した後、上澄み液を除去した後、濃縮した。得られた残渣に、ｎ−ヘプタン２００部を添加、２３℃で３０分間攪拌した後、ろ過することにより、式（Ｂ１−５）で表される塩６１．５４部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３７５．２
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３３９．１ Synthesis Example 6: Synthesis of salt represented by formula (B1-5)

50.49 parts of the salt represented by the formula (B1-5-a) and 252.44 parts of chloroform are charged into a reactor, stirred at 23 ° C. for 30 minutes, and then represented by the formula (B1-5-b). 16.27 parts of the compound was added dropwise and stirred at 23 ° C. for 1 hour to obtain a solution containing a salt represented by the formula (B1-5-c). To the obtained solution containing the salt represented by the formula (B1-5-c), 48.80 parts of the salt represented by the formula (B1-5-d) and 84.15 parts of ion-exchanged water are added, The mixture was stirred at 23 ° C. for 12 hours. Since the resulting reaction solution was separated into two layers, the chloroform layer was separated and removed, and 84.15 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. To the obtained chloroform layer, 3.88 parts of activated carbon was added and stirred, followed by filtration. The collected filtrate was concentrated, 125.87 parts of acetonitrile was added to the resulting residue, and the mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added and stirred at 23 ° C. for 30 minutes, and then the supernatant was removed and concentrated. To the obtained residue, 200 parts of n-heptane was added, stirred at 23 ° C. for 30 minutes, and then filtered to obtain 61.54 parts of a salt represented by the formula (B1-5).
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (−) Spectrum): M ^- 339.1

以下、これらのモノマーをその式番号に応じて、「モノマー（ａ１−１−３）」等という。 Synthesis of Resin (A) Compounds (monomers) used in the synthesis of resin (A) are shown below.

Hereinafter, these monomers are referred to as “monomer (a1-1-3)” or the like according to the formula number.

Synthesis Example 7 [Synthesis of Resin A1]
As the monomer, using monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-3), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-2-3): monomer (a3-1-1)] It mixed so that it might become 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / ion-exchanged water = 4/1 mixing solution to precipitate the resin, and the resin was filtered to obtain a resin A1 having a weight average molecular weight of 7.8 × 10 ³ (co-polymer). Polymer) with a yield of 73%. This resin A1 has the following structural units and was soluble in butyl acetate.

Synthesis Example 8 [Synthesis of Resin A2]
As the monomer, using monomer (a1-1-3), monomer (a1-2-3), monomer (a2-1-3), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-2-3): monomer (a2-1-3): monomer (a3-2-3): monomer (a3-1-1)] It mixed so that it might become 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / ion-exchanged water = 4/1 mixing solution to precipitate the resin, and this resin was filtered to obtain a resin A2 having a weight average molecular weight of 7.8 × 10 ³ (co-polymer). Polymer) with a yield of 70%. This resin A2 had the following structural units and was soluble in butyl acetate.

Synthesis Example 9 [Synthesis of Resin A3]
As the monomer, monomer (a1-z), monomer (a2-1-1), monomer (a3-2-1) and monomer (a5-z) are used, and the molar ratio [monomer (a1-z): monomer ( a2-1-1): monomer (a3-2-1): monomer (a5-z)] is mixed so as to be 30: 20: 40: 10, and propylene at 1.5 times the total monomer amount Glycol monomethyl ether acetate was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol solvent to precipitate the resin, and the resin was filtered. The resin obtained was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol solvent to precipitate the resin, and this resin was filtered twice. 4 × 10 ³ resin A3 was obtained with a yield of 62%. This resin A3 has the following structural units.

Synthesis Example 10 [Synthesis of Resin A4]
As the monomer, using monomer (a1-1-3), monomer (a1-5-1), monomer (a2-1-3), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-5-1): monomer (a2-1-3): monomer (a3-2-1)): monomer (a3-1-1)] However, it mixed so that it might become 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin obtained was dissolved again in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and the weight-average molecular weight was 7. 6 × 10 ³ resin A4 was obtained with a yield of 68%. This resin A4 has the following structural units.

Synthesis Example 12 [Synthesis of Resin H1]
Monomer (a4-z) was used as a monomer, and 4.0 mass times propylene glycol monomethyl ether acetate as a total monomer amount was added to prepare a solution. To the solution, 8 mol% of V-601 (manufactured by Wako Pure Chemical Industries) as an initiator was added with respect to the total monomer amount, and these were heated at 80 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin. Resin H1 having an average molecular weight of 7.6 × 10 ³ was obtained with a yield of 70%. This resin H1 has the following structural units.

<Preparation of resist composition>
Each of the components shown below was dissolved in a solvent in parts by mass shown in Table 1, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

ＩＩ１：式（ＩＩ−１）で表される塩

ＩＩ２：式（ＩＩ−２）で表される塩

ＩＩ３：式（ＩＩ−３）で表される塩

ＩＩ４：式（ＩＩ−４）で表される塩

Ｂ１−５：

Ｚ１：（和光純薬工業（株）製）

<Resin>
Resins A1 to A4 and H1 synthesized in the synthesis example described above
<Acid generator>
I1: Salt represented by formula (I-1) I2: Central Glass Co., Ltd.

II1: Salt represented by the formula (II-1)

II2: salt represented by the formula (II-2)

II3: salt represented by formula (II-3)

II4: salt represented by formula (II-4)

B1-5:

Z1: (Wako Pure Chemical Industries, Ltd.)

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

<Solvent>
Propylene glycol monomethyl ether acetate 265 parts Propylene glycol monomethyl ether 20 parts 2-heptanone 20 parts γ-butyrolactone 3.5 parts

Examples 1 to 10 and Comparative Example 1
<Manufacture of negative resist pattern>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer, and baked under the conditions of 205 ° C. and 60 seconds, whereby an organic layer having a thickness of 78 nm was obtained. An antireflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness of the composition layer after drying (pre-baking) was 85 nm. After coating, the composition layer was formed on the silicon wafer by pre-baking on a direct hot plate for 60 seconds at the temperature described in the “PB” column of Table 1. An ArF excimer laser stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, NA = 1.35, C-quad20 illumination) is applied to the composition layer formed on the silicon wafer, and a trench pattern (pitch 120 nm / trench width) is used. 50 nm) was used, and the exposure amount was changed stepwise to perform exposure. Note that ultrapure water was used as the immersion medium. After the exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 1. Next, the composition layer on the silicon wafer is developed by using a butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution by a dynamic dispensing method at 23 ° C. for 20 seconds, thereby forming a negative resist pattern. Manufactured.

  In the obtained resist pattern, the exposure amount at which the width of the trench pattern was 50 nm was defined as effective sensitivity.

<Focus margin evaluation (DOF)>
A negative resist pattern was manufactured in the same manner as described above except that the exposure was performed while changing the focus stepwise in terms of effective sensitivity. In the obtained resist pattern, the focus range in which the width of the trench pattern is 50 nm ± 5% (47.5 to 52.5 nm) was defined as DOF. The results are shown in Table 2.

Examples 11 to 20 and Comparative Example 2
Except for changing the developer to 2-heptanone (manufactured by Kyowa Hakko Co., Ltd.), the same operation as above was performed to produce a negative resist pattern, and the same evaluation as in Example 1 was performed. The results are shown in Table 3.

  From the above results, it can be seen that according to the method for producing a resist pattern of the present invention, a negative resist pattern can be produced with excellent DOF.

  The production method of the present invention can obtain a resist pattern with excellent DOF, and is useful for fine processing of semiconductors.

Claims (5)

(1) A step of applying a resist composition on a substrate,
(2) a step of drying the resist composition after coating to form a composition layer;
(3) a step of exposing the composition layer;
(4) a step of heating the composition layer after exposure; and (5) a method for producing a resist pattern comprising a step of developing the composition layer after heating with a negative developer,
Resist which is a resist composition in which the resist composition contains a resin containing a structural unit having an acid labile group, an acid generator represented by formula (I) and an acid generator represented by formula (II) Pattern manufacturing method.

[In the formula (I),
X ² represents an alkanediyl group having 1 to 6 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a hydroxy group or —OR ⁵ , and a methylene group constituting the alkanediyl group May be replaced by an oxygen atom or a carbonyl group.
R ⁴ and R ⁵ each independently represent a hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the group may be replaced with an oxygen atom or a carbonyl group.
Z ⁺ represents an organic cation. ]

[In the formula (II),
R ^II3 and R ^II4 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
X ^II1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and the divalent saturated The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
R ^II5 represents a group containing a cyclic ether structure.
Z1 ⁺ represents an organic cation. ]   2. The method for producing a resist pattern according to claim 1, wherein the negative developer is a solvent containing at least one of butyl acetate and 2-heptanone.   3. The method for producing a resist pattern according to claim 1, wherein the step (5) is a step of developing by a dynamic dispensing method. The method for producing a resist pattern according to any one of claims 1 to 3, wherein the acid generator represented by the formula (I) is an acid generator represented by the formula (IA).

[In formula (IA), X ² and Z ⁺ represent the same meaning as described above.
R ⁶ represents a hydrocarbon group having 1 to 17 carbon atoms, the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the methylene group constituting the hydrocarbon group is May be replaced by an oxygen atom or a carbonyl group.
R ⁷ represents an alkyl group having 1 to 6 carbon atoms.
R ⁸ represents a fluorinated alkyl group having 1 to 6 carbon atoms.
However, the total carbon number of R ⁶ , R ⁷ and R ⁸ is 20 or less. ] ^{5. The} method for producing a resist pattern according to claim 1, wherein R ^II5 is a group represented by the formula (IIA) or a group represented by the formula (IIE).

[In Formula (IIA) and Formula (IIE),
s1 represents an integer of 1 to 4. t1 represents the integer of 0-2. However, s1 + t1 is 1-4.
s11 represents an integer of 1 to 4. t11 represents an integer of 0 to 2.
s12 represents an integer of 1 to 4. t12 represents an integer of 0 to 2. However, s12 + t12 is 0-4.
R ^II6 represents a saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group and the aromatic hydrocarbon group has a carbon number 1 to 6 alkyl groups or nitro groups may be substituted, and two of R ^II6 may be bonded to each other to form a ring, and the saturated hydrocarbon group and the methylene group contained in the ring are each an oxygen atom It may be replaced with.
u1 represents an integer of 0 to 8, and when u1 is 2 or more, the plurality of R ^II6 are the same or different.
R ^II7 and R ^II8 are each independently a hydroxy group, a halogen group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, 2 to 7 carbon atoms acyl group, represents an acyloxy group, or an acylamino group having 2 to 7 carbon atoms having 2 to 7 carbon atoms, may form a two but a single bond or a ring bonded to each other of R ^II7 and R ^II8.
u2 and u3 are independently an integer of 0 to 16, if u2 is 2 or more, the plurality of R ^II7 same or different, when u3 is 2 or more, plural R ^II8 are the same or Different.
* Represents a bond to X ^1. ]