WO2011048919A1

WO2011048919A1 - Radiation-sensitive resin composition and novel compound

Info

Publication number: WO2011048919A1
Application number: PCT/JP2010/067001
Authority: WO
Inventors: 研丸山
Original assignee: Jsr株式会社
Priority date: 2009-10-20
Filing date: 2010-09-29
Publication date: 2011-04-28
Also published as: JPWO2011048919A1; JP5617844B2; TW201131299A

Abstract

Disclosed are: a radiation-sensitive resin composition which can response to (extreme) far ultraviolet rays such as a KrF excimer laser and an ArF excimer laser, X-rays such as a synchrotron radiation beam, and electron beams effectively to form a resist film which has good nanoedge roughness and on which a fine pattern can be formed stably with high precision; and others. The radiation-sensitive resin composition comprises an acid generating agent represented by formula (1-1), another specific compound, and a solvent. [In the formula (1-1), M⁺ represents a sulfonium cation represented by formula (2); and n represents an integer of 2 to 10.] [In formula (2), R¹ to R³ independently represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, or at least any two of R¹ to R³ are bound to each other to form a ring together with a sulfur atom contained in the formula.]

Description

Radiation-sensitive resin composition and novel compound

The present invention relates to a radiation-sensitive resin composition and a novel compound. More specifically, the present invention relates to various kinds of radiation such as KrF excimer laser, ArF excimer laser, F ₂ excimer laser, EUV (extreme) far ultraviolet rays, synchrotron radiation, etc., X-rays, electron beam, etc. The present invention relates to a radiation-sensitive resin composition and a novel compound used as a chemically amplified resist suitable for microfabrication.

Conventionally, in the manufacturing process of semiconductor devices such as IC and LSI, fine processing by lithography using a photoresist composition has been performed. In recent years, with the high integration of integrated circuits, the formation of ultrafine patterns in the submicron region and the quarter micron region has been required. Along with this, there is a tendency to shorten the exposure wavelength from g-line to i-line, KrF excimer laser light, and further ArF excimer laser light. Further, in addition to excimer laser light, lithography using electron beams, X-rays, or EUV light is also being developed.

Lithography using EUV light is positioned as a next-generation or next-generation pattern formation technology, and a resist with high sensitivity and high resolution is desired. In particular, high sensitivity is a very important issue for shortening the wafer processing time. However, in the EUV resist, when pursuing higher sensitivity, not only the resolution is lowered but also the nano edge roughness is deteriorated. Therefore, it is strongly desired to develop a resist satisfying these characteristics at the same time. . Nano edge roughness is designed when the pattern is viewed from directly above because the resist pattern and the edge of the substrate interface vary irregularly in the direction perpendicular to the line direction due to the characteristics of the resist. This refers to the deviation that occurs between the dimensions and the actual pattern dimensions. Since the deviation from the design dimension is transferred by an etching process using a resist as a mask and the electrical characteristics are deteriorated, the yield is lowered. In particular, in the ultrafine region of 32 nm or less where EUV is about to be applied, nano edge roughness is an extremely important improvement issue. High sensitivity, high resolution, good pattern shape, and good nanoedge roughness are in a trade-off relationship, and how to satisfy them simultaneously is very important.

Various studies have been made to satisfy high sensitivity, high resolution, good pattern shape and good nano edge roughness at the same time. For example, Patent Documents 1 to 4 disclose radiation-sensitive resin compositions that use a photoacid generator that generates two sulfonic acids from the same molecule. Patent Document 5 discloses a radiation-sensitive resin composition using two types of photoacid generators. Further, Patent Document 6 discloses a radiation-sensitive resin composition that uses a photoacid generator that generates a strong acid and a photoacid generator that generates a weak acid, and Patent Document 7 has a boiling point of 150 ° C. or higher. A radiation-sensitive resin composition using a compound that generates carboxylic acid and a compound that generates an acid other than carboxylic acid is disclosed.

International Publication WO2004 / 107051 Pamphlet JP 2004-359590 A Special table 2007-507580 Japanese Patent Laying-Open No. 2005-092053 JP-A-5-323590 Japanese Patent Laid-Open No. 5-181279 JP-A-11-125907

However, even with the radiation-sensitive resin compositions disclosed in Patent Documents 1 to 7, at present, high sensitivity, high resolution, good pattern shape, and good nanoedge roughness cannot be satisfied at the same time. is there.

The present invention has been made in view of the above-described problems of the prior art, and can be applied to X-rays such as KrF excimer laser, ArF excimer laser, EUV, etc. A radiation-sensitive resin composition capable of forming a chemically amplified positive resist film capable of forming a fine pattern with high accuracy and stability while being effective and having good nano edge roughness, and It aims at providing the novel compound which can be used suitably as a radioactive acid generator.

As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that it is possible to achieve the problems by using a radiation-sensitive resin composition containing a radiation-sensitive acid generator having a specific structure. The headline and the present invention were completed.

The present invention is as follows.
[1] A radiation sensitive acid comprising a radiation sensitive acid generator represented by the following general formula (1-1), a compound represented by the following general formula (X), and a solvent. Resin composition.

[In the general formula (1-1), M ⁺ represents a sulfonium cation represented by the following general formula (2), and the two M ⁺ may be the same or different from each other. n represents an integer of 2 to 10. ]

[In General Formula (2), R ¹ , R ² and R ³ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted group. It represents an aryl group having 6 to 18 carbon atoms, or any two or more of R ¹ , R ² and R ³ are bonded to each other to form a ring together with the sulfur atom in the formula. ]

[In General Formula (X), R ⁵ , R ⁶ and R ⁷ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted group. It represents an aryl group having 6 to 18 carbon atoms, or any two or more of R ⁵ , R ⁶ and R ⁷ are bonded to each other to form a ring together with the sulfur atom in the formula. Y ⁻ is a carboxylate anion. ]
[2] A radiation-sensitive resin composition comprising a radiation-sensitive acid generator represented by the following general formula (1-2) and a solvent.

[In General Formula (1-2), M ⁺ represents a sulfonium cation represented by the following General Formula (2-1-1), and the two M ⁺ may be the same or different from each other. n represents an integer of 2 to 10. ]

[In General Formula (2-1-1), each A independently represents an oxygen atom or a single bond. Each B is independently of each other a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or A substituted or unsubstituted aryl group having 6 to 12 carbon atoms is shown. c, d and e each independently represent an integer of 0 to 2, and at least one of c, d and e is 1 or 2. ]
[3] A compound represented by the following general formula (1-2):

[In General Formula (2-1-1), each A independently represents an oxygen atom or a single bond. Each B is independently of each other a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or A substituted or unsubstituted aryl group having 6 to 12 carbon atoms is shown. c, d and e each independently represent an integer of 0 to 2, and at least one of c, d and e is 1 or 2. ]
[4] The compound according to [3], which is a radiation-sensitive acid generator.

The radiation-sensitive resin composition of the present invention is sensitive to X-rays such as KrF excimer laser, ArF excimer laser, EUV (extreme) deep ultraviolet rays, synchrotron radiation, and electron beams, nano edge roughness, sensitivity and A chemically amplified positive resist film that is excellent in resolution and can form a fine pattern with high accuracy and stability can be formed.
The novel compound of the present invention can be suitably used as a radiation sensitive acid generator in a radiation sensitive resin composition.

It is a typical top view at the time of seeing a line pattern from the upper part. It is typical sectional drawing of a line pattern shape.

Hereinafter, although the form for implementing this invention is demonstrated, this invention is not limited to the following embodiment. That is, it is understood that modifications and improvements as appropriate to the following embodiments are within the scope of the present invention based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. Should be.
Further, “(meth) acrylate” in the present specification means “acrylate” or “methacrylate”.

[1] Radiation sensitive resin composition (I)
Radiation sensitive resin composition of the present invention [hereinafter also referred to as “radiation sensitive resin composition (I)”. ] Is a specific radiation sensitive acid generator [hereinafter also referred to as “acid generator (A1)”. ] And other specific compounds [hereinafter also referred to as “compound (B)”. And a solvent.
According to such a radiation sensitive resin composition containing the acid generator (A1) and the compound (B), a resist film that has a low adverse effect on the environment and the human body and that can obtain a good resist pattern is formed. can do.

[1-1] Radiation sensitive acid generator (A1)
The acid generator (A1) is represented by the following general formula (1-1). Since this acid generator (A1) has a fluorine-containing electron-withdrawing group strong at the α-position of the sulfonyl group in the structure, sulfonic acid having a high acidity (general formula (1a described later) is triggered by exposure or the like. )) Is generated. In addition to functioning as a radiation-sensitive acid generator, the acid generator (A1) has a high boiling point, hardly volatilizes during the photolithography process, and has a short acid diffusion length in the resist film. That is, it has the characteristic that the acid diffusion length is moderate.

N in the general formula (1-1) is an integer of 2 to 10, preferably an integer of 2 to 6, and more preferably 3 or 4.

Examples of the unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms in R ¹ to R ³ of the general formula (2) include, for example, a methyl group, an ethyl group, an n-propyl group, and an i-propyl group. N-butyl group, t-butyl group, n-pentyl group, i-pentyl group, n-hexyl group, i-hexyl group, n-heptyl group, n-octyl group, i-octyl group, n-nonyl group , N-decyl group, 2-ethylhexyl group and the like.
In addition, this alkyl group includes halogen atoms such as fluorine, chlorine, bromine and iodine, hydroxyl groups, thiol groups, and hetero atoms (for example, halogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, etc.) ) May be substituted with a substituent such as an organic group.

Examples of the unsubstituted aryl group having 6 to 18 carbon atoms in R ¹ to R ³ in the general formula (2) include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, and 1-phenanthryl. Groups and the like.
In addition, the aryl group includes a halogen atom such as fluorine, chlorine, bromine and iodine, a hydroxyl group, a thiol group, an alkyl group, and a hetero atom (for example, a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, It may be substituted with a substituent such as an organic group containing a silicon atom).

Of the onium cations represented by the general formula (2), an onium cation represented by the following general formula (2-1) or (2-2) is preferable, and is represented by the following general formula (2-1-1). More preferred is an onium cation.

[In the general formula (2-1), R ^a , R ^b and R ^c are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a thiol group, a substituted or unsubstituted straight chain having 1 to 12 carbon atoms. A branched or branched alkyl group, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, —OSO ₂ —R ^f group, or —SO ₂ —R ^g group, or R ^a , R ^b and Two or more of R ^c are bonded to each other to form a ring. However, when there are a plurality of R ^a , R ^b and R ^c , they may be the same or different. R ^f and R ^g are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms. Or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. q1 to q3 each independently represent an integer of 0 to 5. ]
[In general formula (2-2), R ^d represents a hydrogen atom, a halogen atom, a hydroxyl group, a thiol group, a substituted or unsubstituted linear or branched alkyl group having 1 to 8 carbon atoms, or a substituted or non-substituted group. A substituted aryl group having 6 to 8 carbon atoms is represented, or two or more R ^d are bonded to each other to form a ring. However, when there are a plurality of R ^{d s} , they may be the same or different. R ^e represents a hydrogen atom, a substituted or unsubstituted linear or branched alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 7 carbon atoms, or two or more Of R ^e are bonded to each other to form a ring. However, if R ^e there are a plurality, each of which may be the same or different. q4 represents an integer of 0 to 7, q5 represents an integer of 0 to 6, and q6 represents an integer of 0 to 3. ]

[In General Formula (2-1-1), each A independently represents an oxygen atom or a single bond. Each B is independently of each other a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or A substituted or unsubstituted aryl group having 6 to 12 carbon atoms is shown. c, d and e each independently represent an integer of 0 to 2, and at least one of c, d and e is 1 or 2. ]

Examples of the unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms in R ^a , R ^b and R ^c in the general formula (2-1) include a methyl group, an ethyl group, and an n-propyl group. I-propyl group, n-butyl group, t-butyl group, n-pentyl group, i-pentyl group, n-hexyl group, i-hexyl group, n-heptyl group, n-octyl group, i-octyl group , N-nonyl group, n-decyl group, 2-ethylhexyl group and the like.
In addition, this alkyl group includes halogen atoms such as fluorine, chlorine, bromine and iodine, hydroxyl groups, thiol groups, and hetero atoms (for example, halogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, etc.) ) May be substituted with a substituent such as an organic group.

Examples of the unsubstituted aryl group having 6 to 12 carbon atoms in R ^a , R ^b and R ^c in the general formula (2-1) include a phenyl group and a naphthyl group.
In addition, the aryl group includes a halogen atom such as fluorine, chlorine, bromine and iodine, a hydroxyl group, a thiol group, an alkyl group, and a hetero atom (for example, a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, It may be substituted with a substituent such as an organic group containing a silicon atom).

Examples of the unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms in R ^f and R ^g of the general formula (2-1) include, for example, a methyl group, an ethyl group, an n-propyl group, i- Propyl group, n-butyl group, t-butyl group, n-pentyl group, i-pentyl group, n-hexyl group, i-hexyl group, n-heptyl group, n-octyl group, i-octyl group, n- Nonyl group, n-decyl group, 2-ethylhexyl group and the like can be mentioned.
In addition, this alkyl group includes halogen atoms such as fluorine, chlorine, bromine and iodine, hydroxyl groups, thiol groups, and hetero atoms (for example, halogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, etc.) ) May be substituted with a substituent such as an organic group.

Examples of the unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms in R ^f and R ^g of the general formula (2-1) include a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, an adamantyl group, a norbornyl group, and the like. Is mentioned.
In addition, this alicyclic hydrocarbon group is composed of halogen atoms such as fluorine, chlorine, bromine and iodine, hydroxyl groups, thiol groups, alkyl groups, and heteroatoms (for example, halogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms). , A phosphorus atom, a silicon atom, etc.) may be substituted with a substituent such as an organic group.

Examples of the unsubstituted aryl group having 6 to 12 carbon atoms in R ^f and R ^g in the general formula (2-1) include a phenyl group and a naphthyl group.
In addition, the aryl group includes a halogen atom such as fluorine, chlorine, bromine and iodine, a hydroxyl group, a thiol group, an alkyl group, and a hetero atom (for example, a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, It may be substituted with a substituent such as an organic group containing a silicon atom).

Examples of the unsubstituted linear or branched alkyl group having 1 to 8 carbon atoms for R ^d in the general formula (2-2) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, n-butyl, t-butyl, n-pentyl, i-pentyl, n-hexyl, i-hexyl, n-heptyl, n-octyl, i-octyl, and 2-ethylhexyl Etc.
In addition, this alkyl group includes halogen atoms such as fluorine, chlorine, bromine and iodine, hydroxyl groups, thiol groups, and hetero atoms (for example, halogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, etc.) ) May be substituted with a substituent such as an organic group.

Examples of the unsubstituted aryl group having 6 to 8 carbon atoms in R ^d of the general formula (2-2) include a phenyl group.
In addition, the aryl group includes a halogen atom such as fluorine, chlorine, bromine and iodine, a hydroxyl group, a thiol group, an alkyl group, and a hetero atom (for example, a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, It may be substituted with a substituent such as an organic group containing a silicon atom).

Examples of the unsubstituted linear or branched alkyl group having 1 to 7 carbon atoms in R ^e of the general formula (2-2) include, for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, Examples thereof include an n-butyl group, a t-butyl group, an n-pentyl group, an i-pentyl group, an n-hexyl group, an i-hexyl group, and an n-heptyl group.
In addition, this alkyl group includes halogen atoms such as fluorine, chlorine, bromine and iodine, hydroxyl groups, thiol groups, and hetero atoms (for example, halogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, etc.) ) May be substituted with a substituent such as an organic group.

Examples of the unsubstituted aryl group having 6 to 7 carbon atoms in R ^e of the general formula (2-2) include a phenyl group.
In addition, the aryl group includes a halogen atom such as fluorine, chlorine, bromine and iodine, a hydroxyl group, a thiol group, an alkyl group, and a hetero atom (for example, a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, It may be substituted with a substituent such as an organic group containing a silicon atom).

Examples of the unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms in B of the general formula (2-1-1) include, for example, a methyl group, an ethyl group, an n-propyl group, and an i-propyl group. N-butyl group, t-butyl group, n-pentyl group, i-pentyl group, n-hexyl group, i-hexyl group, n-heptyl group, n-octyl group, i-octyl group, n-nonyl group , N-decyl group, 2-ethylhexyl group and the like.
In addition, this alkyl group includes halogen atoms such as fluorine, chlorine, bromine and iodine, hydroxyl groups, thiol groups, and hetero atoms (for example, halogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, etc.) ) May be substituted with a substituent such as an organic group.

Examples of the unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms in B of the general formula (2-1-1) include a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, an adamantyl group, and a norbornyl group. It is done.
In addition, this alicyclic hydrocarbon group is composed of halogen atoms such as fluorine, chlorine, bromine and iodine, hydroxyl groups, thiol groups, alkyl groups, and heteroatoms (for example, halogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms). , A phosphorus atom, a silicon atom, etc.) may be substituted with a substituent such as an organic group.

Examples of the unsubstituted aryl group having 6 to 12 carbon atoms in B of the general formula (2-1-1) include a phenyl group and a naphthyl group.
In addition, the aryl group includes a halogen atom such as fluorine, chlorine, bromine and iodine, a hydroxyl group, a thiol group, an alkyl group, and a hetero atom (for example, a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, It may be substituted with a substituent such as an organic group containing a silicon atom).

Specific examples of the sulfonium cation represented by the general formula (2), (2-1), (2-2) or (2-1-1) include, for example, the following formulas (i-1) to ( i-81).

Among these sulfonium cations, the above formula (i-1), formula (i-2), formula (i-6), formula (i-8), formula (i-13), formula (i-19) , Formula (i-25), formula (i-27), formula (i-29), formula (i-33), formula (i-64), formula (i-65), (i-66), formula (I-67), formula (i-68), formula (i-69), formula (i-70), formula (i-71), formula (i-72), and formula (i-73) The sulfonium cation is preferably selected from the formulas (i-64), (i-65), (i-66), (i-67), (i-68), (i-69), Particularly preferred are sulfonium cations represented by i-70), formula (i-71), formula (i-72), and formula (i-73).

The sulfonate anion in the acid generator (A1) can be produced, for example, according to a general method described in JP-T-2007-507580.

M ⁺ (sulfonium cation) in the acid generator (A1) is described in, for example, Advances in Polymer Science, Vol. 62, p. 1-48 (1984), Japanese Patent Application Laid-Open No. 2005-104956, and the like.

In addition, the acid generator (A1) contained in the radiation-sensitive resin composition (I) of the present invention generates an acid by dissociation of a monovalent sulfonium cation (M ⁺ ) triggered by exposure or heating. Specifically, the sulfonic acid represented by the following general formula (1a) is generated.

[In the general formula (1), n is an integer of 2 to 10. ]

The method for synthesizing such an acid generator (A1) is not particularly limited. For example, as represented by the following reaction formula, the compound represented by the general formula (Z) and a desired onium cation (M ⁺ ) Halide (for example, M ⁺ Br ⁻ ) can be synthesized in an aqueous solution.

[In General Formula (Z), n is an integer of 2 to 10. ]

In addition, the radiation sensitive resin composition (I) of this invention may contain only 1 type of the above-mentioned acid generator (A1), and may contain 2 or more types.

The content of the acid generator (A1) in the radiation sensitive resin composition (I) of the present invention is usually 0.1 to 50 parts by mass, preferably 1 to 100 parts by mass with respect to 100 parts by mass of the resin (C) described later. The amount is 40 parts by mass, more preferably 5 to 30 parts by mass. When content of an acid generator (A1) is less than 0.1 mass part, there exists a possibility that the effect of this invention may not fully be expressed. On the other hand, when it exceeds 50 parts by mass, there is a possibility that transparency to radiation, pattern shape, heat resistance and the like may be lowered.

[1-2] Compound (B)
The compound (B) is represented by the following general formula (X).
Since the radiation sensitive resin composition (I) of the present invention contains this compound (B), it has a good nano edge roughness and can form a fine pattern with high accuracy and stability. Can be formed. Furthermore, it is possible to form a resist film that has a lower adverse effect on the environment and the human body and can obtain a good resist pattern.

[In General Formula (X), R ⁵ , R ⁶ and R ⁷ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted group. It represents an aryl group having 6 to 18 carbon atoms, or any two or more of R ⁵ , R ⁶ and R ⁷ are bonded to each other to form a ring together with the sulfur atom in the formula. Y ⁻ is a carboxylate anion. ]

Regarding R ⁵ , R ⁶ and R ⁷ in the general formula (X), the description of R ¹ , R ² and R ³ in the general formula (2) can be applied as they are.

Specific examples of the sulfonium cation in the general formula (X) include the above formulas (i-1) to (i-81). Among these, the formula (i-1), the formula (i-2), the formula (i-6), the formula (i-8), the formula (i-13), the formula (i-19), and the formula (i -25), formula (i-27), formula (i-29), formula (i-33), formula (i-64), formula (i-65), (i-66), formula (i-67) ), A formula (i-68), a formula (i-69), a formula (i-70), a formula (i-71), a formula (i-72), and a sulfonium cation represented by the formula (i-73) Preferably, the formula (i-64), formula (i-65), (i-66), formula (i-67), formula (i-68), formula (i-69), formula (i-70) Particularly preferred are sulfonium cations represented by formula (i-71), formula (i-72) and formula (i-73).

In the general formula (X), Y 2 ⁻ is a carboxylate anion and is represented by R ⁹ COO 2 ^— . R ⁹ represents a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted linear or branched alkoxyl group having 1 to 12 carbon atoms, substituted or unsubstituted. An alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 22 carbon atoms.

The linear or branched alkyl group having 1 to 12 carbon atoms and the linear or branched alkoxyl group having 1 to 12 carbon atoms in R ⁹ may be substituted or unsubstituted. It may be. Specific examples of the substituent include, for example, methyl group, ethyl group, propyl group, hydroxyl group, carboxyl group, halogen atom (fluorine atom, bromine atom, etc.), alkoxyl group (methoxy group, ethoxy group, propoxy group, butoxy group) Etc.), alkyloxycarbonyl groups and the like.

Examples of the linear or branched alkyl group having 1 to 12 carbon atoms for R ⁹ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, Examples thereof include 1-methylpropyl group, t-butyl group, trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, dodecafluoropentyl group, perfluorooctyl group and the like. Among these, a methyl group, a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a nonafluorobutyl group are preferable, and a trifluoromethyl group is particularly preferable.

Examples of the linear or branched alkoxyl group having 1 to 12 carbon atoms for R ⁹ include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a 2-methylpropoxy group, Examples thereof include 1-methylpropoxy group and t-butoxy group.

The alicyclic hydrocarbon group having 4 to 20 carbon atoms in R ⁹ may be substituted or unsubstituted. Specific examples of the substituent include, for example, methyl group, ethyl group, propyl group, hydroxyl group, carboxyl group, halogen atom (fluorine atom, bromine atom, etc.), alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group) Etc.), alkyloxycarbonyl groups and the like.

Specific examples of the alicyclic hydrocarbon group having 4 to 20 carbon atoms in R ⁹ include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecanyl group, and cyclododecanyl group. An alkyl group; an adamantyl group, a noradamantyl group, a decalin residue (decalinyl group), a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, and the like.

The aryl group having 6 to 22 carbon atoms in R ⁹ may be substituted or unsubstituted. Specific examples of the substituent include, for example, methyl group, ethyl group, propyl group, hydroxyl group, carboxyl group, halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), alkoxy group (methoxy group, ethoxy group, propoxy group) , Butoxy group and the like), alkyloxycarbonyl group and the like.
Examples of the aryl group having 6 to 22 carbon atoms in R ⁹ include groups derived from the following structures (x-1) to (x-3). When R ⁹ is a group derived from the following (x-2) (that is, a naphthyl group), the bonding positions bonded to the carbon atom of the COO ⁻ site in R ⁹ COO ^— are the 1-position and 2-position. Either may be sufficient. When R ⁹ is a group derived from the following (x-3) (that is, an anthryl group), the bond positions bonded to the carbon atom of the COO ⁻ site in R ⁹ COO ^— are the 1-position, 2-position, and Any of the 9th place may be sufficient.

Such Y ⁻ is particularly preferably CH ₃ COO ⁻ or a carboxylic acid anion represented by the following formulas (3-1) to (3-5).

Compound (B) can be produced, for example, according to a general method described in JP-A-11-125907.

In addition, the radiation sensitive resin composition (I) of this invention may contain only 1 type of the above-mentioned compound (B), and may contain 2 or more types.

The content of the compound (B) in the radiation-sensitive resin composition (I) of the present invention is appropriately determined depending on the type and content of the acid generator (A1) and other acid generators described later used as necessary. Although adjusted, it is usually 0.1 to 30 parts by weight, preferably 1 to 20 parts by weight, and more preferably 5 to 20 parts by weight with respect to 100 parts by weight of the resin (C) described later. When content of a compound (B) is less than 0.1 mass part, there exists a possibility that the effect of this invention may not fully be expressed. On the other hand, when it exceeds 30 parts by mass, there is a possibility that transparency to radiation, pattern shape, heat resistance, and the like are lowered.

[1-3] Resin (C)
The radiation-sensitive resin composition (I) of the present invention contains an alkali-insoluble or hardly-alkali-soluble resin (hereinafter also referred to as “resin (C)”) containing a repeating unit having an acid-dissociable group.
This resin (C) is a resin that becomes readily soluble in alkali by the action of an acid. Here, in the present specification, “alkali insoluble or hardly soluble in alkali” means alkali development that is employed when a resist pattern is formed from a resist film formed from a radiation-sensitive resin composition containing the resin (C). Under the conditions, when a 100 nm-thick film using only the resin (C) is developed instead of the resist film, 50% or more of the initial film thickness of the resist film remains after development.

Since the radiation sensitive resin composition (I) of the present invention contains such a resin (C), it is sensitive to an electron beam or extreme ultraviolet rays in a lithography process, and a fine pattern with high accuracy. In addition, a chemically amplified positive resist film that can be stably formed can be formed.

The repeating unit having an acid dissociable group contained in the resin (C) is one in which the acid dissociable group is dissociated by the action of an acid. The repeating unit is not particularly limited as long as it has the above-described action, but the repeating unit represented by the following general formula (p-1) (hereinafter referred to as “repeating unit (p-1)”), and And at least one of repeating units represented by the following general formula (p-2) (hereinafter referred to as “repeating unit (p-2)”).
By using at least one of the repeating units (p-1) and (p-2) as the repeating unit having such an acid dissociable group, there is an advantage that good sensitivity can be obtained.

[In the general formula (p-1), R ²¹ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group. R ²² is independently of each other a linear or branched alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 22 carbon atoms, or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms. Or a group derived therefrom, or any two R ²² 's bonded to each other to form a divalent alicyclic hydrocarbon group or a group derived therefrom together with the carbon atom to which each is bonded. And the remaining one R ²² is a linear or branched alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 22 carbon atoms, or a monovalent alicyclic carbonization having 4 to 20 carbon atoms. A hydrogen group or a group derived therefrom is shown. ]

[In the general formula (p-2), R ²³ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group. Do R ²⁴ each independently represent a linear or branched alkyl group having 1 to 4 carbon atoms, or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a group derived therefrom? Alternatively, any two R ²⁴ are bonded to each other to form a divalent alicyclic hydrocarbon group or a group derived therefrom together with the carbon atom to which each is bonded, and the remaining one R ²⁴ Represents a linear or branched alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a group derived therefrom. ]

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms in R ²² of the general formula (p-1) include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n- A butyl group, a 2-methylpropyl group, a 1-methylpropyl group, a t-butyl group and the like can be mentioned.

Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms in R ²² of the general formula (p-1) include norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclobutane, cyclopentane, and cyclohexane. , Groups composed of alicyclic rings derived from cycloalkanes such as cycloheptane and cyclooctane.
Examples of the group derived from this alicyclic hydrocarbon group include the above-mentioned monovalent alicyclic hydrocarbon groups such as methyl, ethyl, n-propyl, i-propyl, n- Groups substituted with one or more linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms such as butyl group, 2-methylpropyl group, 1-methylpropyl group and t-butyl group Etc.

Examples of the aryl group having 6 to 22 carbon atoms in R ²² of the general formula (p-1) include groups derived from the following structures (y-1) to (y-3). When R ²² is a group derived from the following (y-2) (that is, a naphthyl group), the carbon atom in the [—O—C (R ²² ) ₃ ] site of the general formula (p-1) The bonding position bonded to (the carbon atom bonded to the oxygen atom) may be either the 1-position or the 2-position. Further, when R ²² is a group derived from the following (y-3) (that is, an anthryl group), a carbon atom in the [—O—C (R ²² ) ₃ ] site of the general formula (p-1) The bonding position for bonding to 1 may be any of the 1st, 2nd and 9th positions.
The aryl group may be substituted. Specific examples of the substituent include, for example, methyl group, ethyl group, hydroxyl group, carboxyl group, halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), alkoxyl group (methoxy group, ethoxy group, propoxy group, butoxy group) Etc.), alkyloxycarbonyl groups and the like.

In addition, as the divalent alicyclic hydrocarbon group formed together with any two R ²² bonded to each other and the carbon atom to which each R ²² is bonded (the carbon atom bonded to the oxygen atom), Examples thereof include divalent alicyclic hydrocarbon groups of 4-20. Specific examples include groups composed of alicyclic rings derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclopentane, cyclohexane and the like.
Further, examples of the group derived from a divalent alicyclic hydrocarbon group formed by bonding R ²² to each other include the above-described divalent alicyclic hydrocarbon group such as a methyl group, an ethyl group, and the like. Linear, branched or cyclic alkyl having 1 to 4 carbon atoms such as n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group and t-butyl group Examples include groups substituted with one or more groups or one or more groups.

Among the repeating units (p-1), repeating units represented by the following general formulas (p-1-1) to (p-1-7) are preferable, and the following general formulas (p-1-2), ( The repeating unit represented by p-1-3) or (p-1-4) is more preferable. When the resin (C) contains these repeating units, an excellent resist pattern can be formed by nano edge roughness.

[In the general formulas (p-1-1) to (p-1-7), R ²¹ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group. R ²⁵ independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 22 carbon atoms. ]

Regarding “linear or branched alkyl group having 1 to 4 carbon atoms” and “aryl group having 6 to 22 carbon atoms” in R ²⁵ of general formulas (p-1-1) to (p-1-7) Respectively, the description of “a linear or branched alkyl group having 1 to 4 carbon atoms” and “aryl group having 6 to 22 carbon atoms” in R ²² of the general formula (p-1) is applied as it is. be able to.

The resin (C) may contain only one type of repeating unit (p-1), or may contain two or more types.

Further, in R ²⁴ of the general formula (p-2), “a linear or branched alkyl group having 1 to 4 carbon atoms”, “a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or Regarding the “derived group” and “a divalent alicyclic hydrocarbon group or a group derived therefrom together with any two R ²⁴ bonded to each other and the carbon atom to which each is bonded”, “A linear or branched alkyl group having 1 to 4 carbon atoms”, “a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof, in R ²² of the general formula (p-1). And the description of “a group that is divalent alicyclic hydrocarbon group or a group derived therefrom” together with the carbon atom to which any two of R ²² are bonded to each other. Can do.

Of the repeating units (p-2), repeating units represented by the following general formula (p-2-1) are preferred. When the resin (C) contains such a repeating unit, an excellent resist pattern can be formed by nano edge roughness.

[In the general formula (p-2-1), R ²³ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group. R ²⁶ independently represents a linear or branched alkyl group having 1 to 4 carbon atoms. ]

The “straight or branched alkyl group having 1 to 4 carbon atoms” in R ²⁶ of the general formula (p-2-1) is the same as “the number of carbon atoms of 1 to 4 in R ²² of the general formula (p-1)”. The description of “4 linear or branched alkyl group” can be applied as it is.

The resin (C) may contain only one type of repeating unit (p-2), or may contain two or more types.

In addition, the resin (C) in the present invention includes, in addition to the above repeating units (p-1) and (p-2), repeating units represented by the following general formulas (c-1) to (c-4). It is preferable to contain at least one of them.

[In the general formula (c-1), R ¹¹ represents a hydrogen atom or a methyl group. R ¹² represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a linear or branched alkoxyl group having 1 to 12 carbon atoms. k and l each independently represent an integer of 0 to 3 (provided that k + l ≦ 5 is satisfied). ]

[In the general formula (c-2), R ¹³ represents a hydrogen atom or a methyl group. R ¹⁴ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a linear or branched alkoxyl group having 1 to 12 carbon atoms. m and n each independently represent an integer of 0 to 3 (provided that m + n ≦ 5 is satisfied). ]

[In the general formula (c-3), R ¹⁵ represents a hydrogen atom or a methyl group. R ¹⁶ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a linear or branched alkoxyl group having 1 to 12 carbon atoms. p and q each independently represent an integer of 0 to 3 (provided that p + q ≦ 5 is satisfied). ]

[In the general formula (c-4), R ¹⁷ represents a hydrogen atom or a methyl group. R ¹⁸ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a linear or branched alkoxyl group having 1 to 12 carbon atoms. r and s each independently represent an integer of 0 to 3. ]

When the resin (C) in the present invention contains a repeating unit represented by the general formula (c-1) (hereinafter referred to as “repeating unit (c-1)”), a resist pattern excellent in nanoedge roughness Can be formed.

Examples of the linear or branched alkyl group having 1 to 12 carbon atoms in R ¹² of the general formula (c-1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and n-butyl. Group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like. Among these, a methyl group, an ethyl group, an n-butyl group, and a t-butyl group are preferable because of excellent nanoedge roughness.

Examples of the linear or branched alkoxyl group having 1 to 12 carbon atoms in R ¹² of the general formula (c-1) include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group. Group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group and the like. Among these, a methoxy group and an ethoxy group are preferable because of excellent nano edge roughness.

K in the general formula (c-1) is an integer of 0 to 3, and preferably 1 or 2. L is an integer of 0 to 3, and preferably an integer of 0 to 2.

Specific examples of the repeating unit (c-1) include repeating units represented by the following formulas (c-1-1) to (c-1-4).
The repeating unit (c-1) may be included in the resin (C) only in one kind or in two or more kinds.

The repeating unit (c-1) can be obtained by using the corresponding hydroxystyrene derivative as a monomer. Moreover, it can also obtain by using as a monomer the compound from which a hydroxy styrene derivative is obtained by hydrolyzing.

Examples of the monomer used to produce the repeating unit (c-1) include p-acetoxystyrene, p- (1-ethoxy) styrene, p-isopropenylphenol and the like. When p-acetoxystyrene is used, the repeating unit (c-1) is produced by performing a side chain hydrolysis reaction after the polymerization reaction.

When the resin (C) in the present invention contains a repeating unit represented by the general formula (c-2) (hereinafter referred to as “repeating unit (c-2)”), a resist pattern excellent in nanoedge roughness Can be formed.

Examples of the linear or branched alkyl group having 1 to 12 carbon atoms and the linear or branched alkoxyl group having 1 to 12 carbon atoms in R ¹⁴ of the general formula (c-2) are as described above. Examples thereof are the same as those of a linear or branched alkyl group having 1 to 12 carbon atoms and a linear or branched alkoxyl group having 1 to 12 carbon atoms in R ¹² of the general formula (c-1). be able to.

M in the general formula (c-2) is an integer of 0 to 3, and is preferably 0 or 1. N is an integer of 0 to 3, and is preferably 1 or 2.

Specific examples of the repeating unit (c-2) include repeating units represented by the following formulas (c-2-1) and (c-2-2).
The repeating unit (c-2) may be contained in the resin (C) only in one kind or in two or more kinds.

The repeating unit (c-2) can be obtained by using a corresponding monomer.
Examples of the monomer used to produce the repeating unit (c-2) include 4-hydroxyphenyl acrylate and 4-hydroxyphenyl methacrylate.

When the resin (C) in the present invention contains a repeating unit represented by the general formula (c-3) (hereinafter referred to as “repeating unit (c-3)”), a resist pattern excellent in nanoedge roughness Can be formed.

Examples of the linear or branched alkyl group having 1 to 12 carbon atoms and the linear or branched alkoxyl group having 1 to 12 carbon atoms in R ¹⁶ of the general formula (c-3) are as described above. Examples thereof are the same as those of a linear or branched alkyl group having 1 to 12 carbon atoms and a linear or branched alkoxyl group having 1 to 12 carbon atoms in R ¹² of the general formula (c-1). be able to.

P in the general formula (c-3) is an integer of 0 to 3, and preferably 1 or 2. Q is an integer of 0 to 3, and is preferably 0 or 1.

Specific examples of the repeating unit (c-3) include repeating units represented by the following formulas (c-3-1) and (c-3-2).
Note that the repeating unit (c-3) may be included in the resin (C) alone or in combination of two or more.

The repeating unit (c-3) can be obtained by using a corresponding monomer.
Examples of the monomer used for producing the repeating unit (c-3) include N- (4-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) methacrylamide and the like.

When the resin (C) in the present invention contains a repeating unit represented by the general formula (c-4) (hereinafter referred to as “repeating unit (c-4)”), a resist pattern excellent in nanoedge roughness Can be formed.

Examples of the linear or branched alkyl group having 1 to 12 carbon atoms and the linear or branched alkoxyl group having 1 to 12 carbon atoms in R ¹⁸ of the general formula (c-4) are as described above. Examples thereof are the same as those of a linear or branched alkyl group having 1 to 12 carbon atoms and a linear or branched alkoxyl group having 1 to 12 carbon atoms in R ¹² of the general formula (c-1). be able to.

R in the general formula (c-4) is an integer of 0 to 3, and preferably 1 or 2. Further, s is an integer of 0 to 3, and is preferably 0 or 1.

Specific examples of the repeating unit (c-4) include repeating units represented by the following formulas (c-4-1) and (c-4-2).
Note that the repeating unit (c-4) may be contained in the resin (C) alone or in combination of two or more.

The repeating unit (c-4) can be obtained by using a corresponding monomer.
Examples of the monomer used for producing the repeating unit (c-4) include 5-hydroxynaphthalen-1-yl methacrylate and 5-hydroxynaphthalen-1-yl acrylate.

Resin (C) is a non-acid dissociable compound other than the above-mentioned repeating units (p-1) and (p-2) and repeating units (c-1) to (c-4) [action of acid. It may further contain a repeating unit (hereinafter referred to as “repeating unit (c-5)”) derived from a compound that does not contain a group (acid-dissociable group) that is dissociated by.
When the resin (C) in the present invention contains the repeating unit (c-5), an excellent resist pattern can be formed by nano edge roughness.

Examples of the non-acid dissociable compound for producing the repeating unit (c-5) include styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, isobornyl acrylate, Examples include cyclodecanyl (meth) acrylate, tetracyclododecenyl (meth) acrylate, and a compound represented by the following formula (c-5-1). Among these, styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, tricyclodecanyl acrylate, and a compound represented by the following formula (c-5-1) are preferable.
The repeating unit (c-5) may be included in the resin (C) only in one kind, or in two or more kinds.

The content ratio of the repeating unit having an acid dissociable group in the resin (C) [particularly, the total content ratio of the repeating units (p-1) and (p-2)] is the number of all repeating units included in the resin (C). When the total of the units is 100 mol%, it is preferably 1 mol% or more, more preferably 20 to 70 mol%, still more preferably 20 to 60 mol%. When this content rate is less than 1 mol%, nano edge roughness may be deteriorated. When this content is 1 mol% or more (particularly 20 to 70 mol%), a resist film exhibiting excellent nano edge roughness can be formed.

The total content of the repeating units (c-1) to (c-4) in the resin (C) is 95 mol% when the total of all the repeating units contained in the resin (C) is 100 mol%. The content is preferably 1 to 95 mol%, more preferably 1 to 95 mol%, still more preferably 10 to 95 mol%, and particularly preferably 40 to 80 mol%. When this content rate exceeds 95 mol%, there exists a possibility that nano edge roughness may deteriorate. In addition, when this content rate is 1 mol% or more, the resist film excellent in nano edge roughness can be formed.

The total content of the repeating units (p-1), (p-2), and (c-1) to (c-4) in the resin (C) is the total content of all the repeating units included in the resin (C). When the total is 100 mol%, it is preferably 10 mol% or more, more preferably 40 to 100 mol%, still more preferably 50 to 100 mol%. When this content rate is less than 10 mol%, there exists a possibility that nano edge roughness may deteriorate. In addition, when this content rate is 10 mol% or more, the resist film which exhibits the outstanding nano edge roughness can be formed.

The content ratio of the repeating unit (c-5) in the resin (C) is preferably 60% by mole or less when the total of all the repeating units contained in the resin (C) is 100% by mole, Preferably, it is 0 to 50 mol%. When this content rate exceeds 60 mol%, there exists a possibility that nano edge roughness may deteriorate. Moreover, when it is 60 mol% or less, the resist film excellent in the balance of the performance of resolution performance and nanoedge roughness can be formed.

The method for synthesizing the resin (C) is not particularly limited, and can be obtained by, for example, known radical polymerization or anionic polymerization. Further, the side chain phenol moiety or naphthol moiety in the above repeating units (c-1) to (c-4) is obtained by reacting the obtained resin (C) with an acetoxy group or the like in an organic solvent in the presence of a base or an acid. Can be obtained by hydrolysis.

The radical polymerization is, for example, for generating at least one of the above repeating units (p-1) and (p-2) in a suitable organic solvent in a nitrogen atmosphere in the presence of a radical polymerization initiator. It can be carried out by stirring and heating the monomer and, if necessary, the monomer for producing the above-mentioned repeating units (c-1) to (c-5).

Examples of the radical polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobis- (4-methoxy-). 2,4-dimethylvaleronitrile) 2,2'-azobismethylbutyronitrile, 2,2'-azobiscyclohexanecarbonitrile, cyanomethylethylazoformamide, 2,2'-azobis (2,4-dimethylpropion) Acid methyl), azo compounds such as 2,2′-azobiscyanovaleric acid; benzoyl peroxide, lauroyl peroxide, 1,1′-bis- (t-butylperoxy) cyclohexane, 3,5,5-trimethylhexa Organic peroxides such as noyl peroxide and t-butylperoxy-2-ethylhexanoate, and hydrogen peroxide .

In the polymerization, if necessary, a polymerization aid such as 2,2,6,6-tetramethyl-1-piperidinyloxy, iodine, mercaptan, styrene dimer may be added.

The reaction temperature in the radical polymerization is not particularly limited and can be appropriately set depending on the type of the initiator, but can be set to, for example, 50 to 200 ° C. In particular, when an azo initiator or a peroxide initiator is used, a temperature at which the half life of the initiator is about 10 minutes to about 30 hours is preferable, and a temperature at which the half life of the initiator is about 30 minutes to about 10 hours. More preferably it is.

The reaction time varies depending on the type of initiator and the reaction temperature, but the reaction time during which 50% or more of the initiator is consumed is preferred, and in many cases is about 0.5 to 24 hours.

In the anionic polymerization, for example, a monomer that provides at least one of the above repeating units (p-1) and (p-2) in a suitable organic solvent in the presence of an anionic polymerization initiator in a nitrogen atmosphere. In addition, the monomer that gives the above-mentioned repeating units (c-1) to (c-5) can be stirred and maintained at a predetermined temperature if necessary.

Examples of the anionic polymerization initiator include n-butyllithium, s-butyllithium, t-butyllithium, ethyllithium, ethylsodium, 1,1-diphenylhexyllithium, 1,1-diphenyl-3-methylpentyllithium, etc. The organic alkali metal is mentioned.

The reaction temperature in the anionic polymerization is not particularly limited and can be appropriately set depending on the type of the initiator. In particular, when alkyl lithium is used as an initiator, the temperature is preferably −100 to 50 ° C., more preferably −78 to 30 ° C.

In addition, in the synthesis | combination of resin (C), without using a polymerization initiator, it can also superpose | polymerize by heating and can employ | adopt cationic polymerization.

In addition, when the side chain of the resin (C) is hydrolyzed to introduce the side chain phenol moiety or naphthol moiety in the above repeating units (c-1) to (c-4), the hydrolysis reaction is performed. Examples of the acid that can be used include p-toluenesulfonic acid and its hydrate, methanesulfonic acid, trifluoromethanesulfonic acid, malonic acid, succinic acid, 1,1,1-fluoroacetic acid, and other organic acids; sulfuric acid, Examples include inorganic acids such as hydrochloric acid, phosphoric acid, hydrobromic acid; pyridinium p-toluenesulfonate, ammonium p-toluenesulfonate, 4-methylpyridinium p-toluenesulfonate, and the like.

Examples of the base include inorganic bases such as potassium hydroxide, sodium hydroxide, sodium carbonate and potassium carbonate; organic bases such as triethylamine, N-methyl-2-pyrrolidone, piperidine and tetramethylammonium hydroxide. It is done.

Examples of the organic solvent that can be used for the polymerization and the hydrolysis include ketones such as acetone, methyl ethyl ketone, and methyl amyl ketone; ethers such as diethyl ether and tetrahydrofuran (THF); methanol, ethanol, propanol, and the like. Alcohols; aliphatic hydrocarbons such as hexane, heptane, and octane; aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated alkyls such as chloroform, bromoform, methylene chloride, methylene bromide, and carbon tetrachloride; Esters such as ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cellosolves; dimethylformamide, dimethyl sulfoxide, hexamethylphosphoramide It includes aprotic polar solvents such as is.
Among these, acetone, methyl amyl ketone, methyl ethyl ketone, tetrahydrofuran, methanol, ethanol, propanol, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate are preferable.

The weight average molecular weight in terms of polystyrene (hereinafter also referred to as “Mw”) measured by gel permeation chromatography (GPC) of the resin (C) is preferably 2000 to 100,000, more preferably 2000 to 40000, More preferably, it is 2000 to 25000.
Further, the ratio (Mw / Mn) of the Mw of the resin (C) and the polystyrene-equivalent number average molecular weight (hereinafter also referred to as “Mn”) measured by GPC is preferably 1 to 5, more preferably. Is 1 to 3, more preferably 1 to 2.5.

In addition, the radiation sensitive resin composition (I) of this invention may contain only 1 type of the above-mentioned resin (C), and may contain 2 or more types.

[1-4] Acid diffusion controller (D)
The radiation-sensitive resin composition (I) of the present invention includes an acid diffusion controller (hereinafter referred to as “acid diffusion controller (D)” in addition to the acid generator (A), the compound (B), and the resin (C). It is preferable to further contain.
This acid diffusion control agent (D) controls the diffusion phenomenon in the resist film of the acid generated from the acid generator (A) or the compound (B) by exposure, and suppresses an undesirable chemical reaction in a non-exposed region. It is what has.

The storage stability of the resulting radiation-sensitive resin composition is improved by including such an acid diffusion controller (D). In addition, the resolution of the formed resist film is further improved, and changes in the line width of the resist pattern due to fluctuations in the holding time (PED) from after exposure to post-exposure heat treatment can be suppressed, resulting in process stability. A radiation-sensitive resin composition that is extremely excellent in the resistance is obtained.

Examples of the acid diffusion controller (D) include nitrogen-containing organic compounds and photosensitive basic compounds.
Examples of the nitrogen-containing organic compound include a compound represented by the following general formula (4) (hereinafter referred to as “nitrogen-containing compound (i)”), a compound having two nitrogen atoms in the same molecule (hereinafter, “ Nitrogen-containing compound (ii) ”), polyamino compounds and polymers having three or more nitrogen atoms (hereinafter collectively referred to as“ nitrogen-containing compound (iii) ”), amide group-containing compounds, urea compounds, nitrogen-containing compounds And heterocyclic compounds.

In the general formula (4), each R ⁴¹ is independently of each other a hydrogen atom, an optionally substituted linear, branched or cyclic alkyl group, an optionally substituted aryl group, or a substituted group. An aralkyl group which may be present.

^Examples of the alkyl group in R ⁴¹ of the general formula (4) include a linear or branched alkyl group having 1 to 30 carbon atoms and a cyclic alkyl group having 3 to 30 carbon atoms. Specifically, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, cyclopropyl group, cyclopentyl Group, cyclohexyl group, adamantyl group, norbornyl group and the like.

^Examples of the aryl group for R ⁴¹ in the general formula (4) include aryl groups having 6 to 14 carbon atoms. Specifically, a phenyl group, a tolyl group, a naphthyl group etc. are mentioned, for example.

Examples of the aralkyl group in R ⁴¹ of the general formula (4) include aralkyl groups having 6 to 12 carbon atoms. Specific examples include a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and the like.

In addition, the alkyl group, aryl group and aralkyl group described above may be substituted. Specific examples of the substituent include, for example, methyl group, ethyl group, provir group, n-butyl group, t-butyl group, hydroxyl group, carboxyl group, halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), alkoxyl. Groups (methoxy group, ethoxy group, propoxy group, butoxy group, etc.) and the like.

Examples of the nitrogen-containing compound (i) include mono (cyclo) alkylamines, di (cyclo) alkylamines, substituted alkylamines, and aromatic amines.

Examples of the nitrogen-containing compound (ii) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenyl ether. 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, , 4-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, bis (2-dimethylaminoethyl) ) Ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2- Midazorijinon, 2 quinoxalinium linoleic, N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine, and the like.

Examples of the nitrogen-containing compound (iii) include polymers of polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide, and the like.

Examples of amide group-containing compounds include Nt-butoxycarbonyl group-containing amino compounds, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, Examples include propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, and isocyanuric acid tris (2-hydroxyethyl).

Examples of urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea. Etc.

Examples of nitrogen-containing heterocyclic compounds include imidazoles, pyridines, piperazines, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine. 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, 3- (N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2. 2.2] octane and the like.

In addition, these acid diffusion control agents (D) may be used individually by 1 type, and may be used in combination of 2 or more type.

The content of the acid diffusion controller (D) is preferably 15 parts by mass or less, more preferably 0.001 to 10 parts by mass, and still more preferably 0.005 with respect to 100 parts by mass of the resin (C). Is 5 parts by mass. When the content of the acid diffusion controller exceeds 15 parts by mass, the sensitivity of the formed resist film and the developability of the exposed part may be deteriorated. When the amount is less than 0.001 part by mass, the pattern shape and dimensional fidelity of the formed resist film may be lowered depending on the process conditions.

[1-5] Solvent (E)
The radiation sensitive resin composition (I) of the present invention contains a solvent (hereinafter also referred to as “solvent (E)”).
Examples of the solvent (E) include ethylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, propylene glycol monoalkyl ether acetates, lactic acid esters, formic acid esters, and acetic acid esters. , Propionic acid esters, esters, aromatic hydrocarbons, ketones, amides, lactones and the like. These solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

The content of the solvent (E) is preferably such that the total solid concentration of the radiation-sensitive resin composition is 1 to 70% by mass, more preferably 1 to 15% by mass, and still more preferably Is an amount of 1 to 10% by mass. When this content is less than 1% by mass, the viscosity is too high, so that coating may be difficult. On the other hand, when it exceeds 70 mass%, it may be difficult to form a resist film having a sufficient thickness.

The radiation-sensitive resin composition (I) of the present invention comprises the above-described acid generator (A), compound (B), resin (C), acid diffusion controller (D), and other acid generators described later. An additive such as a surfactant can be prepared by uniformly dissolving in the solvent (E) so that the total solid content concentration is in the above range. In addition, after preparing in this way, it is preferable to filter with a filter with a pore diameter of about 0.2 μm, for example.

[1-6] Other Radiation Sensitive Acid Generator In addition to the acid generator (A1) and compound (B) described above, the radiation sensitive resin composition (I) of the present invention includes other radiation sensitive compounds. An acid generator (hereinafter also referred to as “other acid generator”) can be further blended.
Examples of other acid generators include onium salt compounds and sulfonic acid compounds other than the acid generator (A1) and the compound (B).

Examples of the onium salt compounds include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, and pyridinium salts.
Examples of the sulfonic acid compound include alkyl sulfonic acid esters, alkyl sulfonic acid imides, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and imino sulfonates.

Among these other acid generators, specifically, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) ) Iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, cyclohexyl 2-oxocyclohexyl methyl Sulphonium trifluoromethanesulfonate, dicyclohexyl-2-oxocyclohexylsulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethyl Trifluoromethanesulfonate,

Trifluoromethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide Perfluoro-n-octanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, N-hydroxysuccinimide trifluoromethanesulfonate, N-hydroxysuccinimide nonafluoro-n- Butanesulfonate, N-hydroxysuccinimide perfluoro-n-octanesulfonate, 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate, triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, Phenylsulfonium-2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate, triphenylsulfonium-2-bicyclo [2.2.1] hept-2-yl-1,1, 2,2-tetrafluoroethanesulfonate, 4-butoxy-1-naphthyltetrahydrothiophenium nonafluorobutanesulfonate and 4-butoxy-1-naphthyltetrahydrothiophenium-2-bicyclo [2.2.1] hepta-2 -Yl-1,1,2,2-tetrafluoroethanesulfonate is preferred.
In addition, these other acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.

The content of the other acid generator is 0 to 80 parts by mass with respect to 100 parts by mass of the acid generator (A1) from the viewpoint of ensuring the sensitivity and developability of the resist film formed from the radiation-sensitive resin composition. Parts, and more preferably 0 to 50 parts by mass. When the content of the other acid generator exceeds 80 parts by mass, the resolution performance may be deteriorated.

[1-7] Other components The radiation-sensitive resin composition (I) of the present invention includes the above-described acid generator (A1), compound (B), resin (C), acid diffusion controller (D), In addition to the solvent (E) and other acid generators, various additives such as a surfactant, a sensitizer, and an aliphatic additive can be further blended as other components.

The surfactant is a component having an action of improving coating properties, striations, developability and the like.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate. In addition to nonionic surfactants such as polyethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (above, manufactured by Tochem Products), MegaFuck F171, F173 (above, manufactured by Dainippon Ink and Chemicals), Florad FC430, FC431 (manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 ( As mentioned above, Asahi Glass Co., Ltd.) can be mentioned. These surfactants may be used individually by 1 type, and may be used in combination of 2 or more type.

The content of the surfactant is preferably 2 parts by mass or less, more preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the resin (C).

The sensitizer absorbs radiation energy and transmits the energy to the acid generator (A1) and the compound (B), thereby increasing the amount of acid generated. It has the effect of improving the apparent sensitivity of the resin composition.
Examples of such sensitizers include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. In addition, these sensitizers may be used individually by 1 type, and may be used in combination of 2 or more type.

The content of the sensitizer is preferably 20 parts by mass or less, more preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the resin (C).

Also, by blending a dye or pigment, the latent image in the exposed area can be visualized, and the influence of halation during exposure can be mitigated. Moreover, the adhesiveness of a resist film and a board | substrate can be improved by containing an adhesion aid.

The alicyclic additive is a component having a function of further improving dry etching resistance, pattern shape, adhesion to a substrate, and the like.
Examples of such alicyclic additives include 1-adamantane carboxylic acid, 2-adamantanone, 1-adamantane carboxylic acid t-butyl, 1-adamantane carboxylic acid t-butoxycarbonylmethyl, 1-adamantane carboxylic acid α. -Butyrolactone ester, 1,3-adamantane dicarboxylate di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di-t-butyl, 2, Adamantane derivatives such as 5-dimethyl-2,5-di (adamantylcarbonyloxy) hexane; t-butyl deoxycholic acid, t-butoxycarbonylmethyl deoxycholic acid, 2-ethoxyethyl deoxycholic acid, 2-deoxycholic acid 2- Cyclohexyloxyethyl, deoxy Deoxycholic acid esters such as 3-oxocyclohexyl cholic acid, tetrahydropyranyl deoxycholic acid, mevalonolactone ester of deoxycholic acid; t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, Lithocholic acid esters such as 2-cyclohexyloxyethyl lithocholic acid, 3-oxocyclohexyl lithocholic acid, tetrahydropyranyl lithocholic acid, mevalonolactone lithocholic acid; 3- [2-hydroxy-2,2-bis (trifluoromethyl) ) Ethyl] tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecane and the like. In addition, these alicyclic additives may be used individually by 1 type, and may be used in combination of 2 or more type.

The content of the alicyclic additive is preferably 20 parts by mass or less, more preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the resin (C). When this content exceeds 20 mass parts, there exists a possibility that the heat resistance of the formed resist film may fall.

In addition to these additives, an alkali-soluble polymer, a low-molecular alkali-solubility control agent having an acid-dissociable protecting group, an antihalation agent, a storage stabilizer, an antifoaming agent, etc. may be blended. it can.

[2] Radiation sensitive resin composition (II)
Radiation sensitive resin composition of the present invention [hereinafter also referred to as “radiation sensitive resin composition (II)”. ] Is a specific radiation sensitive acid generator [hereinafter also referred to as “acid generator (A2)”. And a solvent.
According to the radiation-sensitive resin composition containing such an acid generator (A2), it is possible to form a resist film that has a low adverse effect on the environment and the human body and can provide a good resist pattern.

[2-1] Radiation sensitive acid generator (A2)
The acid generator (A2) is represented by the following general formula (1-2). Since this acid generator (A2) has a strong fluorine-containing electron-withdrawing group at the α-position of the sulfonyl group in the structure, sulfonic acid with high acidity is generated upon exposure or the like. In addition to functioning as a radiation-sensitive acid generator, the acid generator (A2) has a high boiling point, hardly volatilizes during the photolithography process, and has a short acid diffusion length in the resist film. That is, it has the characteristic that the acid diffusion length is moderate.

N in the general formula (1-2) is an integer of 2 to 10, preferably an integer of 2 to 6, and more preferably 3 or 4.

Further, regarding the sulfonium cation represented by the general formula (2-1-1), the description of the sulfonium cation represented by the general formula (2-1-1) in the radiation sensitive resin composition (I) described above. Can be applied as is.

The description of the acid generator (A1) in the radiation-sensitive resin composition (I) can be applied as it is to each production method of the sulfonate anion and sulfonium cation in the acid generator (A2).
Moreover, this acid generator (A2) can be synthesized in the same manner as the acid generator (A1) in the above-mentioned radiation-sensitive resin composition (I).

In addition, the radiation sensitive resin composition (II) of this invention may contain only 1 type of the above-mentioned acid generator (A2), and may contain 2 or more types.

The content of the acid generator (A2) in the radiation sensitive resin composition (II) of the present invention is usually 0.1 to 50 parts by mass, preferably 1 to 100 parts by mass with respect to 100 parts by mass of the resin (C) described later. The amount is 40 parts by mass, more preferably 5 to 30 parts by mass. When content of an acid generator (A2) is less than 0.1 mass part, there exists a possibility that the effect of this invention may become difficult to fully express. On the other hand, when it exceeds 50 parts by mass, there is a possibility that transparency to radiation, pattern shape, heat resistance and the like may be lowered.

[2-2] Compound (B)
The radiation-sensitive resin composition (II) of the present invention preferably further contains the compound (B) represented by the general formula (X) in addition to the acid generator (A2) described above. In this case, it is possible to form a resist film that has a lower adverse effect on the environment and the human body and can obtain a good resist pattern. In addition, about the compound (B), the description of the compound (B) in the above-mentioned radiation sensitive resin composition (I) can be applied as it is.
Moreover, the radiation sensitive resin composition (II) of this invention may contain only 1 type of compounds (B), and may contain 2 or more types.

The content of the compound (B) in the radiation-sensitive resin composition (II) of the present invention is appropriately determined depending on the type and content of the acid generator (A2) and other acid generators described later used as necessary. Although adjusted, it is preferably 30 parts by mass or less, more preferably 0.1 to 30 parts by mass, still more preferably 1 to 20 parts by mass, particularly preferably 100 parts by mass of the resin (C) described later. Is 5 to 20 parts by mass. When content of a compound (B) exceeds 30 mass parts, there exists a possibility that transparency with respect to a radiation, a pattern shape, heat resistance, etc. may fall.

[2-3] Resin (C)
The radiation sensitive resin composition (II) of the present invention contains an alkali-insoluble or hardly-alkali-soluble resin (hereinafter also referred to as “resin (C)”) containing a repeating unit having an acid-dissociable group. In addition, about resin (C), the description of resin (C) in the above-mentioned radiation sensitive resin composition (I) is applicable as it is.
Moreover, the radiation sensitive resin composition (II) of this invention may contain only 1 type of resin (C), and may contain 2 or more types.

[2-4] Acid diffusion controller (D)
The radiation-sensitive resin composition (II) of the present invention includes an acid diffusion controller (hereinafter referred to as “acid diffusion controller (D)” in addition to the acid generator (A2), the compound (B), and the resin (C). It is preferable to further contain. In addition, about acid diffusion control agent (D), description of the acid diffusion control agent (D) in the above-mentioned radiation sensitive resin composition (I) is applicable as it is.
Moreover, the radiation sensitive resin composition (II) of this invention may contain only 1 type of acid diffusion control agents (D), and may contain 2 or more types.

[2-5] Solvent (E)
The radiation sensitive resin composition (II) of the present invention contains a solvent (hereinafter also referred to as “solvent (E)”). In addition, about solvent (E), the description of the solvent (E) in the above-mentioned radiation sensitive resin composition (I) is applicable as it is.
Moreover, the radiation sensitive resin composition (II) of this invention may contain only 1 type of solvent (E), and may contain 2 or more types.

[2-6] Other Radiation Sensitive Acid Generator In addition to the acid generator (A2) and compound (B) described above, the radiation sensitive resin composition (II) of the present invention includes other radiation sensitivity. An acid generator (hereinafter also referred to as “other acid generator”) can be further blended. In addition, about another acid generator, description of the other acid generator in the above-mentioned radiation sensitive resin composition (I) is applicable as it is.
Moreover, the radiation sensitive resin composition (II) of this invention may contain only 1 type of other acid generators, and may contain it 2 or more types.

[2-7] Other components The radiation-sensitive resin composition (II) of the present invention includes the acid generator (A2), the compound (B), the resin (C), the acid diffusion controller (D), In addition to the solvent (E) and other acid generators, various additives such as a surfactant, a sensitizer, and an aliphatic additive can be further blended as other components. In addition to these additives, an alkali-soluble polymer, a low-molecular alkali-solubility control agent having an acid-dissociable protecting group, an antihalation agent, a storage stabilizer, an antifoaming agent, etc. may be blended. it can. In addition, about each of these components, each description in the above-mentioned radiation sensitive resin composition (I) can be applied as it is.
Moreover, each of these components may be used individually by 1 type, and may be used in combination of 2 or more type.

[3] Novel Compound The novel compound of the present invention is represented by the following general formula (1-2).

In the general formula (1-2), n is an integer of 2 to 10, preferably an integer of 2 to 6, and more preferably 3 or 4.
Regarding the sulfonium cation represented by the general formula (2-1-1), the description of the sulfonium cation represented by the general formula (2-1-1) in the above-described radiation-sensitive resin composition (I) is not changed. Can be applied.

The novel compound of the present invention can be suitably used as a radiation sensitive acid generator in a radiation sensitive resin composition. In particular, it can be suitably used as the acid generator (A1) or (A2) in the radiation-sensitive resin composition described above.

The description of the acid generator (A1) in the radiation-sensitive resin composition (I) can be applied as it is to each production method of the sulfonate anion and sulfonium cation in the novel compound.
Moreover, this novel compound can be synthesized in the same manner as the acid generator (A1) in the above-mentioned radiation sensitive resin composition (I).

[4] Method for Forming Resist Pattern Each radiation-sensitive resin composition of the present invention is useful as a material capable of forming a chemically amplified positive resist film. In the chemically amplified positive resist film, the acid-dissociable group in the resin (C) is eliminated by the action of the acid generated from the acid generator (A1) or (A2) by exposure, and the resin (C) becomes alkaline. It becomes soluble. That is, an alkali-soluble site is generated in the resist film. This alkali-soluble portion is an exposed portion of the resist, and this exposed portion can be dissolved and removed by an alkali developer. In this way, a positive resist pattern having a desired shape can be formed. This will be specifically described below.

In order to form a resist pattern using the radiation-sensitive resin composition of the present invention, first, a resist film is formed with the radiation-sensitive resin composition of the present invention.
As the radiation-sensitive resin composition, for example, as described above, after adjusting the total solid content concentration, it can be filtered with a filter having a pore diameter of about 0.2 μm. By applying this radiation-sensitive resin composition to a substrate such as a silicon wafer or a wafer coated with aluminum by an appropriate coating means such as spin coating, cast coating or roll coating, a resist film is formed. Form. Thereafter, in some cases, heat treatment (hereinafter referred to as “PB”) may be performed in advance at a temperature of about 70 to 160 ° C.

Next, this resist film is exposed so that a predetermined resist pattern is formed. Examples of radiation that can be used for this exposure include (extreme) far ultraviolet rays such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), EUV (extreme ultraviolet light, wavelength 13.5 nm, etc.), and synchro Examples include X-rays such as tron radiation, and charged particle beams such as electron beams. Moreover, exposure conditions, such as exposure amount, can be suitably selected according to the composition of the radiation-sensitive resin composition, the type of additive, and the like. This exposure can also be immersion exposure.

After the exposure, it is preferable to perform a heat treatment (hereinafter referred to as “PEB”). By this PEB, it is possible to smoothly proceed with elimination of the acid dissociable group of the resin (C). The heating conditions for PEB can be appropriately selected depending on the composition of the radiation sensitive resin composition, but it is preferably 30 to 200 ° C, more preferably 50 to 170 ° C.

In the present invention, in order to maximize the potential of the radiation-sensitive resin composition, as disclosed in, for example, Japanese Patent Publication No. 6-12452 (Japanese Patent Laid-Open No. 59-93448) An organic or inorganic antireflection film can also be formed on the substrate. In order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film can be provided on the resist film as disclosed in, for example, Japanese Patent Laid-Open No. 5-188598. These techniques can be used in combination.

Next, a predetermined resist pattern is formed by developing the exposed resist film. Examples of the developer used for development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, Triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [ 4.3.0] An alkaline aqueous solution in which at least one alkaline compound such as 5-nonene is dissolved is preferable.

The concentration of the alkaline aqueous solution is preferably 10% by mass or less. When the concentration of the alkaline aqueous solution exceeds 10% by mass, the unexposed area may be dissolved in the developer. The developer is preferably pH 8 to 14, more preferably pH 9 to 14.

Also, for example, an organic solvent can be added to the developer composed of an alkaline aqueous solution. Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methanol, ethanol, n-propyl alcohol, i Alcohols such as propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane; ethyl acetate And esters such as n-butyl acetate and i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonylacetone and dimethylformamide. These organic solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

The compounding amount of the organic solvent is preferably 100 parts by volume or less with respect to 100 parts by volume of the alkaline aqueous solution. When the blending amount of the organic solvent exceeds 100 parts by volume, the developability is lowered, and there is a possibility that the remaining development in the exposed part increases. In addition, an appropriate amount of a surfactant or the like can be added to the developer composed of an alkaline aqueous solution. In addition, after developing with the developing solution which consists of alkaline aqueous solution, it can also wash with water and can be dried.

Hereinafter, the embodiments of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Here, “part” and “%” are based on mass unless otherwise specified.

[1] Synthesis of Resin and Acid Generator (Synthesis Example 1-1) Synthesis of Resin (C-1) 53 g of p-acetoxystyrene, a compound represented by the following formula (M-1) (hereinafter referred to as “Compound (M -1) ”), 48 g of azobisisobutyronitrile (hereinafter referred to as“ AIBN ”) and 1 g of t-dodecyl mercaptan were dissolved in 150 g of propylene glycol monomethyl ether, and then the reaction temperature was changed under a nitrogen atmosphere. The polymerization was carried out for 16 hours while maintaining at 70 ° C. After the polymerization, the reaction solution was dropped into 1000 g of n-hexane to coagulate and purify the copolymer. Next, 150 g of propylene glycol monomethyl ether was again added to the copolymer, and then 150 g of methanol, 37 g of triethylamine and 7 g of water were further added, and a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the obtained copolymer was dissolved in 150 g of acetone, then dropped into 2000 g of water to solidify, and the resulting white powder was filtered and filtered at 50 ° C. under reduced pressure. Dried overnight.
The obtained copolymer had Mw of 6000 and Mw / Mn of 1.9, and as a result of ¹³ C-NMR analysis, the repeating unit derived from p-hydroxystyrene and the repeating derived from compound (M-1) were obtained. The copolymer had a unit content ratio (mol ratio) of 60:40. Hereinafter, this copolymer is referred to as a resin (C-1).

Synthesis Example 1-2 Synthesis of Resin (C-2) 55 g of p-acetoxystyrene, 45 g of a compound represented by the following formula (M-2) (hereinafter also referred to as “compound (M-2)”), 4 g of AIBN , And 1 g of t-dodecyl mercaptan were dissolved in 100 g of propylene glycol monomethyl ether, and polymerization was carried out for 16 hours while maintaining the reaction temperature at 70 ° C. in a nitrogen atmosphere. After the polymerization, the reaction solution was dropped into 1000 g of n-hexane to coagulate and purify the copolymer. Next, 150 g of propylene glycol monomethyl ether was added to the copolymer again, and then 150 g of methanol, 34 g of triethylamine, and 6 g of water were further added, and a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the obtained copolymer was dissolved in 150 g of acetone, then dropped into 2000 g of water to solidify, and the resulting white powder was filtered and filtered at 50 ° C. under reduced pressure. Dried overnight.
The obtained copolymer had Mw of 10,000 and Mw / Mn of 2.1. As a result of ¹³ C-NMR analysis, the repeating unit derived from p-hydroxystyrene and the repeating derived from compound (M-2) were obtained. The copolymer had a unit content ratio (mol ratio) of 65:35. Hereinafter, this copolymer is referred to as a resin (C-2).

(Synthesis Example 1-3) Synthesis of Resin (C-3) 31.63 g (35 mol%) of a compound represented by the following formula (M-3) (hereinafter also referred to as “compound (M-3)”), 49.60 g (45 mol%) of a compound represented by the following formula (M-4) (hereinafter also referred to as “compound (M-4)”), a compound represented by the following formula (M-5) (hereinafter, referred to as “compound (M-4)”) 6.45 g (10 mol%) (also referred to as “compound (M-5)”) was dissolved in 200 g of 2-butanone, and then 8.14 g of 2,2′-azobis (2-methylpropionitrile) was added. A monomer solution was prepared. Next, a 1000 ml three-necked flask charged with 12.32 g (10 mol%) of the compound (M-2) and 100 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reaction vessel was stirred at 80 ° C. with stirring. The heated monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or less, poured into 4000 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was dispersed in 400 g of methanol and washed in the form of a slurry, followed by filtration, followed by filtration twice, followed by vacuum drying at 50 ° C. for 17 hours to obtain a white powder (copolymer). Obtained.
The obtained copolymer had Mw of 4300 and Mw / Mn of 1.30, and as a result of ¹³ C-NMR analysis, compound (M-2), compound (M-3), compound (M-4) The content of each repeating unit represented by the compound (M-5) was a copolymer of 8.9: 35.6: 46.2: 9.3 (mol%). This copolymer is referred to as “polymer (C-3)”.

Synthesis Example 2-1 Synthesis of Acid Generator (A-1) 8.8 g of a compound represented by the following formula (X-1), 3.9 g of a compound represented by the following formula (X-2), water 100 g and 100 g of dichloromethane were mixed and stirred at room temperature for 3 hours. After completion of the stirring, the organic layer was recovered, and the organic layer was washed 8 times with 50 g of water. Thereafter, dichloromethane in the organic layer was distilled off under reduced pressure, and the resulting solid was dried at 50 ° C. for 12 hours. As a result of ¹ H-NMR and ¹⁹ F-NMR analysis, the obtained copolymer was a compound represented by the following formula (A-1).

Synthesis Example 2-2 Synthesis of Acid Generator (A-2) 6.0 g of the compound represented by the following formula (X-3), 3.9 g of the compound represented by the above formula (X-2), water 100 g and 100 g of dichloromethane were mixed and stirred at room temperature for 3 hours. After completion of the stirring, the organic layer was recovered, and the organic layer was washed 8 times with 50 g of water. Thereafter, dichloromethane in the organic layer was distilled off under reduced pressure, and the resulting solid was dried at 50 ° C. for 12 hours. The resulting copolymer was a compound represented by the following formula (A-2) as a result of ¹ H-NMR and ¹⁹ F-NMR analyses.

Synthesis Example 2-3 Synthesis of Acid Generator (A-3) 7.5 g of a compound represented by the following formula (X-4), 3.9 g of a compound represented by the above formula (X-2), water 100 g and 100 g of dichloromethane were mixed and stirred at room temperature for 3 hours. After completion of the stirring, the organic layer was recovered, and the organic layer was washed 8 times with 50 g of water. Thereafter, dichloromethane in the organic layer was distilled off under reduced pressure, and the resulting solid was dried at 50 ° C. for 12 hours. As a result of ¹ H-NMR and ¹⁹ F-NMR analysis, the obtained copolymer was a compound represented by the following formula (A-3).

In addition, the measurement of the weight average molecular weight (Mw) and the number average molecular weight (Mn) in the present Example uses Tosoh Corporation GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL), flow rate: 1.0 ml / min, Elution solvent: Tetrahydrofuran, Column temperature: It was measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under analysis conditions of 40 ° C. Further, the degree of dispersion Mw / Mn was calculated from the measurement results.
¹ H-NMR, ¹³ C-NMR, and ¹⁹ F-NMR analysis were measured using a model “JNM-ECX400” manufactured by JEOL.

[2] Preparation of radiation-sensitive resin composition (Example 1)
As shown in Table 1, 100 parts of resin (C-1) prepared in Synthesis Example (1-1), 20 parts of acid generator (A-1), 2 parts of compound (B-1), acid diffusion controller By mixing 1 part of (D-1), 2500 parts of solvent (E-1) and 1100 parts of solvent (E-2), the resulting liquid mixture was filtered through a membrane filter having a pore size of 200 nm. A composition solution of the resin composition was prepared.

(Examples 2 to 13 and Comparative Examples 1 to 3)
Resin (C), acid generator (A), compound (B), acid diffusion controller (D) and solvent (E) were mixed in the amounts shown in Table 1, and the resulting mixture was mixed with a pore size of 200 nm. Each of the composition solutions (radiation sensitive resin compositions) of Examples 2 to 13 and Comparative Examples 1 to 3 was prepared by filtration using a membrane filter.

The details of the acid generator (A), compound (B), resin (C), acid diffusion controller (D) and solvent (E) in Table 1 are shown below.

<Acid generator (A)>
(A-1): Acid generator (A-1) obtained in Synthesis Example (2-1)
(A-2): Acid generator (A-2) obtained in Synthesis Example (2-2)
(A-3): Acid generator (A-3) obtained in Synthesis Example (2-3)
(A-1): Compound represented by the following formula (a-1)

<Compound (B)>
(B-1): Compound represented by the following formula (B-1) (B-2): Compound represented by the following formula (B-2)

<Resin (C)>
(C-1): Resin (C-1) obtained in Synthesis Example (1-1)
(C-2): Resin (C-2) obtained in Synthesis Example (1-2)
(C-3): Resin (C-3) obtained in Synthesis Example (1-3)
<Acid diffusion control agent (D)>
(D-1): Tri-n-octylamine <Solvent (E)>
(E-1): Ethyl lactate (E-2): Propylene glycol monomethyl ether acetate (E-3): Cyclohexanone

[3-1] Evaluation of radiation-sensitive resin composition (EB exposure)
After spin-coating the composition solution (the radiation sensitive resin compositions of Examples 1 to 5, 8, 9 and Comparative Example 1) on a silicon wafer in “Clean Track ACT-8” manufactured by Tokyo Electron Ltd. Then, PB (heat treatment) was performed under the conditions shown in Table 2 to form a resist film having a thickness of 50 nm. Thereafter, the resist film was irradiated with an electron beam using a simple electron beam drawing apparatus (manufactured by Hitachi, Ltd., model “HL800D”, output: 50 KeV, current density: 5.0 amperes / cm ² ). After the electron beam irradiation, PEB was performed under the conditions shown in Table 2. Thereafter, using a 2.38% tetramethylammonium hydroxide aqueous solution, development was carried out at 23 ° C. for 1 minute by the paddle method, followed by washing with pure water and drying to form a resist pattern.
Each evaluation test was performed on the resist pattern thus formed, and the evaluation results are shown in Table 2.

(3-1-1) Sensitivity (L / S)
A pattern (a so-called line-and-space pattern (1L1S)) including a line portion having a line width of 110 nm and a space portion (that is, a groove) having an interval of 110 nm formed by adjacent line portions is formed in a one-to-one relationship. The exposure amount formed in the line width was set as the optimum exposure amount, and the sensitivity (μC / cm ² ) was evaluated based on the optimum exposure amount.

(3-1-2) Nano edge roughness (i)
A line-and-space pattern (1L1S) line pattern having a design line width of 110 nm was observed with a semiconductor scanning electron microscope (high-resolution FEB length measuring device, trade name “S-9220”, manufactured by Hitachi, Ltd.). With respect to the observed shape, as shown in FIG. 1 and FIG. 2, the line width and the design line at the most conspicuous portion of the unevenness generated along the lateral surface 2 a of the line portion 2 of the resist film formed on the silicon wafer 1. The difference “ΔCD” from the width of 110 nm was measured by CD-SEM (manufactured by Hitachi High-Technologies Corporation, “S-9220”) to evaluate nanoedge roughness. In addition, the unevenness | corrugation shown in FIG.1 and FIG.2 is exaggerated from actuality.

(3-1-3) Resolution (L / S)
For the line-and-space pattern (1L1S), the minimum line width (nm) of the line pattern resolved with the optimum exposure dose was taken as the resolution.

[3-2] Evaluation of radiation-sensitive resin composition (KrF exposure)
After spin-coating the composition solution (the radiation sensitive resin compositions of Examples 6 to 7, 10, 11 and Comparative Example 2) on a silicon wafer in “Clean Track ACT-8” manufactured by Tokyo Electron Ltd. PB (heat treatment) was performed under the conditions shown in Table 3 to form a resist film having a thickness of 50 nm. Thereafter, using a trade name “Scanner NSR-S203B” (manufactured by Nikon Corporation, numerical aperture = 0.68, σ = 0.75), exposure was performed through a binary mask, and PEB was performed under the conditions shown in Table 3. Thereafter, a 2.38% tetramethylammonium hydroxide aqueous solution was used and developed by a paddle method using an LD nozzle at 23 ° C. for 30 seconds, washed with pure water, and dried to form a resist pattern.
Each evaluation test was performed on the resist pattern thus formed, and the evaluation results are shown in Table 3.

(3-2-1) Sensitivity (L / S)
A pattern (a so-called line-and-space pattern (1L1S)) including a line portion having a line width of 110 nm and a space portion (that is, a groove) having an interval of 110 nm formed by adjacent line portions is formed in a one-to-one relationship. The exposure amount formed in the line width was set as the optimum exposure amount, and the sensitivity (mJ / cm ² ) was evaluated based on the optimum exposure amount.

(3-2-2) Nano edge roughness (i)
A line-and-space pattern (1L1S) line pattern having a design line width of 110 nm was observed with a semiconductor scanning electron microscope (high-resolution FEB length measuring device, trade name “S-9220”, manufactured by Hitachi, Ltd.). With respect to the observed shape, as shown in FIG. 1 and FIG. 2, the line width and the design line at the most conspicuous portion of the unevenness generated along the lateral surface 2 a of the line portion 2 of the resist film formed on the silicon wafer 1. The difference “ΔCD” from the width of 110 nm was measured by CD-SEM (manufactured by Hitachi High-Technologies Corporation, “S-9220”) to evaluate nanoedge roughness. In addition, the unevenness | corrugation shown in FIG.1 and FIG.2 is exaggerated from actuality.

[3-3] Evaluation of radiation-sensitive resin composition (ArF exposure)]
On the 12-inch silicon wafer on which the lower antireflection film (“ARC66”, manufactured by Nissan Chemical Industries, Ltd.) was formed, the radiation-sensitive resin composition (the radiation-sensitive resin compositions of Examples 12 and 13 and Comparative Example 3) was used. A film with a thickness of 75 nm was formed, and PB was performed under the conditions shown in Table 4. Next, a coating film having a film thickness of 90 nm is formed on the formed film by spin coating the composition for forming an upper layer film described in Example 1 of WO2008 / 047678 and performing PB (90 ° C., 60 seconds). Formed. This film was exposed through a mask pattern using an ArF excimer laser immersion exposure apparatus (“NSR S610C”, manufactured by NIKON) under the conditions of NA = 1.3, ratio = 0.800, and annular. After the exposure, PEB was performed under the conditions shown in Table 3. Thereafter, development was performed with a 2.38% tetramethylammonium hydroxide aqueous solution, washed with water, and dried to form a positive resist pattern.
Each evaluation test was performed on the resist pattern thus formed, and the evaluation results are shown in Table 4.

(3-3-1) MEEF (Mask Error Enhancement Factor)
The exposure amount at which a line-and-space (LS) pattern with a line width of 50 nm is formed by exposing through a mask pattern with a target size of 50 nm 1 L / 1S under the above evaluation conditions was defined as the optimum exposure amount. Next, an LS pattern with a pitch of 100 nm is formed using a mask pattern with an optimum exposure amount and a line width target size of 46 nm, 48 nm, 50 nm, 52 nm, and 54 nm, and the line width formed on the resist film is changed to Hitachi. Measured length SEM: measured with CG4000.
At this time, the slope of the straight line when the target size (nm) was plotted on the horizontal axis and the line width (nm) formed on the resist film using each mask pattern was plotted on the vertical axis was calculated as MEEF.
Note that the lower the MEEF value, the lower the mask creation cost.

(3-3-2) Nano edge roughness (ii)
The exposure amount at which a resist pattern with a line width of 50 nm was formed by exposing through a mask pattern with a target size of 50 nm 1 L / 1.8 S under the above evaluation conditions was determined as the optimum exposure amount. When observing the 50nm 1L / 1.8S pattern obtained at the optimum exposure dose from the top of the pattern with Hitachi measurement SEM: CG4000, the line width was observed at 10 arbitrary points, and the measurement variation was observed. The value expressed by 3 sigma was defined as nano edge roughness (LWR).
In addition, it shows that the linearity of a pattern is excellent, so that the value of LWR is small.

(3-3-3) Minimum collapse size Under the above evaluation conditions, exposure was performed while changing the exposure amount by 1 mJ / cm ² through a mask pattern having a target size of 50 nm 1 L / 1.8 S. The line width of the pattern formed at an exposure dose that is 1 mJ / cm ² smaller than the exposure dose at which the line collapse occurred was measured with a length measuring SEM (manufactured by Hitachi, Ltd., model number “CG4000”) to obtain the minimum collapse dimension. .
In addition, it shows that the tolerance with respect to the fall of a pattern is so high that this value is small.

As is apparent from Tables 2, 3 and 4, the radiation sensitive resin compositions of Examples 1 to 13 containing specific acid generators are compared to the radiation sensitive resin compositions of Comparative Examples 1 to 3. Thus, a chemically amplified positive resist film capable of effectively sensitive to electron beams or extreme ultraviolet rays, low roughness, and capable of forming a fine pattern with high accuracy and stability could be formed. .

The radiation-sensitive resin composition of the present invention is not only excellent in the resolution of line and space pattern at the time of resist pattern formation, but also excellent in nano edge roughness, so it is useful for fine pattern formation by EB, EUV or X-ray. It is. Therefore, the radiation-sensitive resin composition of the present invention is extremely useful as a material capable of forming a chemically amplified resist for manufacturing semiconductor devices, which is expected to be further miniaturized in the future.
The novel compound of the present invention can be suitably used as a radiation sensitive acid generator in a radiation sensitive resin composition.

1; base material, 2; resist pattern, 2a; lateral side of resist pattern.

Claims

A radiation-sensitive resin composition comprising: a radiation-sensitive acid generator represented by the following general formula (1-1); a compound represented by the following general formula (X); and a solvent. .

[In the general formula (1-1), M + represents a sulfonium cation represented by the following general formula (2), and the two M + may be the same or different from each other. n represents an integer of 2 to 10. ]

[In General Formula (2), R 1 , R 2 and R 3 are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted group. It represents an aryl group having 6 to 18 carbon atoms, or any two or more of R 1 , R 2 and R 3 are bonded to each other to form a ring together with the sulfur atom in the formula. ]

[In General Formula (X), R 5 , R 6 and R 7 are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted group. It represents an aryl group having 6 to 18 carbon atoms, or any two or more of R 5 , R 6 and R 7 are bonded to each other to form a ring together with the sulfur atom in the formula. Y − is a carboxylate anion. ]
A radiation-sensitive resin composition comprising a radiation-sensitive acid generator represented by the following general formula (1-2) and a solvent.

[In General Formula (1-2), M + represents a sulfonium cation represented by the following General Formula (2-1-1), and the two M + may be the same or different from each other. n represents an integer of 2 to 10. ]

[In General Formula (2-1-1), each A independently represents an oxygen atom or a single bond. Each B is independently of each other a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or A substituted or unsubstituted aryl group having 6 to 12 carbon atoms is shown. c, d and e each independently represent an integer of 0 to 2, and at least one of c, d and e is 1 or 2. ]
A compound represented by the following general formula (1-2):

[In General Formula (1-2), M + represents a sulfonium cation represented by the following General Formula (2-1-1), and the two M + may be the same or different from each other. n represents an integer of 2 to 10. ]

[In General Formula (2-1-1), each A independently represents an oxygen atom or a single bond. Each B is independently of each other a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or A substituted or unsubstituted aryl group having 6 to 12 carbon atoms is shown. c, d and e each independently represent an integer of 0 to 2, and at least one of c, d and e is 1 or 2. ]
The compound according to claim 3, which is a radiation-sensitive acid generator.