JP5347433B2 - Novel sulfonate and derivative thereof, photoacid generator, resist material and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoacid generator that is highly sensitive to an ArF excimer laser beam and the like, gives no concerns about the accumulation in the human body, generates an acid (photoacid) having sufficiently high acidity, has high solubility in a resist solvent, and is excellently compatible with a resin, and a resist material comprising such a photoacid generator. <P>SOLUTION: The photoacid generator generates a sulfonic acid represented by general formula (2) (wherein n is an integer of 1-10; and R is a 1-20C substituted or unsubstituted linear, branched or cyclic alkyl or alkenyl group, a 6-15C substituted or unsubstituted aryl group, or a 4-15C heteroaryl group). A resist pattern formed by using such a photoacid generator exhibits excellent performances in adhesion to a substrate and etching resistance. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a novel sulfonic acid salt and derivatives thereof suitably used as a photoacid generator for a resist material, a photoacid generator, a resist material using the same, and a pattern forming method.

In recent years, along with higher integration and higher speed of LSI, pattern rule miniaturization is progressing rapidly. The background of this is the shortening of the wavelength of the exposure light source. For example, by shortening the wavelength from a mercury lamp i-line (365 nm) to a KrF excimer laser (248 nm), a DRAM (dynamic size of 0.25 μm or less) DRAM (dynamic Random access memory) is now available for mass production. Furthermore, in order to realize DRAM manufacturing with an integration degree of 256M and 1G or more, lithography using an ArF excimer laser (193 nm) has been studied in earnest, and 65 nm by combining with a high NA lens (NA ≧ 0.9). Node devices are being studied. Its While the use of F ₂ laser having a wavelength of 157nm to device fabrication of the next 45nm node is a candidate. Cost of the scanner, changes of the optical system, a number of issues that supposition theory the low etching resistance and the like of the resist Application was postponed. Then, ArF immersion lithography has been proposed as an alternative to F ₂ lithography, and is currently being developed for its early introduction.

  As a resist suitable for such an exposure wavelength, “chemically amplified resist material” has attracted attention. This contains a radiation-sensitive acid generator (hereinafter referred to as “photoacid generator”) that forms an acid upon irradiation with radiation (hereinafter referred to as “exposure”), and the acid generated by exposure is used as a catalyst. It is a pattern forming material that forms a pattern by changing the solubility of the exposed portion and the non-exposed portion in the developer by a reaction.

  Various studies have been made on photoacid generators used in such chemically amplified resist materials. When a photoacid generator that generates alkane or arenesulfonic acid as used in a chemically amplified resist material using a conventional KrF excimer laser beam as a light source is used as a component of the ArF chemically amplified resist material. It has been found that the acid strength for cleaving the acid labile group of the resin is not sufficient, the resolution is not possible at all, or the sensitivity is low and it is not suitable for device production.

  For this reason, as the photoacid generator for the ArF chemically amplified resist material, those that generate perfluoroalkanesulfonic acid having high acid strength are generally used. However, perfluorooctanesulfonic acid, or a derivative thereof, The acronym is known as PFOS, and stability (non-degradability) derived from C—F bonds, hydrophobicity, bioaccumulative properties derived from lipophilicity, and accumulation are problematic. Furthermore, perfluoroalkanesulfonic acid having 5 or more carbon atoms or derivatives thereof are beginning to raise the above problem.

In order to deal with such problems related to PFOS, partial fluorine-substituted alkanesulfonic acids having a reduced fluorine substitution rate have been developed by various companies. For example, in Patent Document 1, an α, α-difluoroalkane sulfonate is developed from an α, α-difluoroalkene and a sulfur compound, and a photoacid generator that generates this sulfonic acid upon exposure, specifically di ( A resist material containing 4-tert-butylphenyl) iodonium = 1,1-difluoro-2- (1-naphthyl) ethanesulfonate is disclosed, and Patent Document 2 further discloses α, α, β, Development of α, α, β, β-tetrafluoroalkane sulfonate using β-tetrafluoro-α-iodoalkane and a sulfur compound, and a photoacid generator and a resist material for generating the sulfonic acid have been disclosed. In addition, although Patent Document 3 does not describe a synthesis method, the text includes difluorosulfoacetate alkyl ester (1- (alkoxycarbonyl) -1,1-difluoromethanesulfonate), difluorosulfoacetamide (1-carbamoyl). -1,1-difluoromethanesulfonate) and the like, and Patent Document 4 discloses triphenylsulfonium (adamantan-1-ylmethyl) oxycarbonyldifluoromethane without any description of synthesis examples. Sulfonate, Patent Document 5 discloses triphenylsulfonium alkyloxycarbonyldifluoromethane sulfonate having a lactone skeleton. Patent Document 6 also discloses triphenylsulfonium 2-acyloxy-1,1,3,3,3-hexafluoropropanesulfonate.
JP-T-2004-531749 Japanese Patent Laid-Open No. 2004-2252 JP 2002-214774 A Japanese Patent Laid-Open No. 2004-4561 JP 2006-306856 A European Patent Publication No. 1710230A1

  In the case of precise line width control, it is important that chemically amplified resists not only have excellent resolution performance, but also have excellent film surface smoothness after resist pattern formation. . Chemically amplified resists with inferior film surface smoothness result in pattern irregularities (nano edge roughness) being transferred to the substrate when the resist pattern is transferred to the substrate by etching or other processing. Dimensional system is reduced. For this reason, it is known that the electrical characteristics of the device may be ultimately lost.

  Also, in order to obtain excellent smoothness, the photoacid generator used in such a chemically amplified resist material needs to be uniformly dispersed in the resist material. Therefore, the solubility of the photoacid generator in the resist solvent and the compatibility with the resin are extremely important.

  However, the solubility of the photoacid generator derived from partially fluorine-substituted alkanesulfonic acid that has been developed so far in the resist solvent and the compatibility with the resin are not yet satisfactory, and a sufficient amount of photoacid is generated. There is a problem that a high level of film surface smoothness cannot be obtained because the agent cannot be dissolved.

  The present invention has been made in view of the above circumstances. Among ultraviolet rays, far ultraviolet rays, extreme ultraviolet rays, electron beams, X-rays, excimer lasers, gamma rays, synchrotron radiation irradiation, etc., particularly ArF excimer laser light In addition to exhibiting excellent performance in terms of substrate adhesion and etching resistance, there is no problem with human accumulation, and the acidity of the generated acid (photogenerated acid) is sufficiently high. Not only has an appropriate boiling point and a moderately short diffusion length in the resist film, but also has high solubility in resist solvents and excellent compatibility with resins. An object of the present invention is to provide an acid generator (sulfonic acid onium salt) and a resist material containing such a photoacid generator. Furthermore, it aims at providing the pattern formation method which obtains a favorable pattern shape by using such a resist material.

  The acid generated from the photoacid generator has sufficient acid strength, has appropriate diffusion in the resist material, has a sufficiently high boiling point and low volatility, has little elution into water, After use, various things are required, such as being able to be decomposed without imposing a load on the environment and being well soluble in resist solvents and resins. Among them, acid strength, environmental load, solubility in a resist solvent, and compatibility with a resin are particularly important. Until now, it has been difficult to simultaneously control all of acid strength, environmental load, solubility in a resist solvent, and compatibility with a resin. Specifically, the higher the fluorine content, the higher the acid strength tends to increase. However, the environmental load problems such as bioaccumulation and accumulation become larger, and further diffusion in the resist film. There was a problem that the greater the substituent introduced to control the length, the lower the solubility in the resist solvent and the compatibility with the resin. For this reason, acids generated from conventional photoacid generators do not satisfy all of the above requirements.

  The inventors of the present invention have made extensive studies in order to solve the above problems. As a result, a fluorine-containing sulfonate or a fluorine-containing sulfonic acid group-containing compound having a structure represented by the general formula (A)

I came to find.
(In the formula, n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 1 to 20 carbon atoms. A linear, branched or cyclic alkenyl group, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms, a is 1 or 0)
In the formula, when a = 1, the whole parenthesis of the general formula (A) takes a −1 valent anion and combines with a counter cation to form “fluorinated sulfonate” as a whole chemical species. . On the other hand, when a = 0, the oxygen at the right end “—O” in the general formula (A) is bonded to another atom through a single bond, and the entire chemical species is “a compound containing a fluorine-containing sulfonic acid group” "

  Among these, it has been found that the fluorine-containing sulfonic acid represented by the following general formula (2) is a sufficiently strong acid despite the relatively low fluorine content and is useful for forming a resist pattern.

(In the formula, n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 1 to 20 carbon atoms. A linear, branched or cyclic alkenyl group, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms.)
Furthermore, the precursor compound that generates the fluorinated sulfonic acid by light (referred to as “photoacid generator”) has a much higher compatibility with a resist (base resin / resist solvent) than conventional products, For this reason, it has been found that a resist pattern that is much better in resolution than conventional products can be formed. It has also been found that the resist pattern formed in this manner also exhibits excellent performance in terms of substrate adhesion and etching resistance.

  The fluorine-containing sulfonic acids represented by the general formula (2) have two fluorine atoms at the α-position carbon of the sulfonic acid group, and also have a “urethane bonding site” on the opposite side of the sulfonic acid group. It is. That is, the direct bonding of two fluorine atoms to the α-position carbon results in a significant increase in the acid strength of adjacent sulfonic acid groups, and this acid strength is impaired by “urethane bonds” in the molecule. There is no. As a result, a photoacid generator having a small number of fluorine atoms and a markedly reduced burden on the environment was realized.

  In such a basic skeleton of the carbon chain, the introduction of a “urethane bond” further improves the solubility of the “precursor compound (photoacid generator)” in the resist solvent and the compatibility with the base resin. It turns out that it improves. As a result, a resist pattern having excellent resolution can be provided by using a resist material containing the photoacid generator.

  As such a “precursor compound (photoacid generator)”, a fluorine-containing sulfonic acid onium salt represented by the general formula (3),

(In the formula, n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 1 to 20 carbon atoms. A linear, branched or cyclic alkenyl group, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms is shown.

Q ⁺ represents a sulfonium cation represented by the following general formula (a) or the following general formula (b), or an iodonium cation represented by the following general formula (c).

In the general formula (a), R ¹ , R ² and R ³ are each independently a substituted or unsubstituted C 1-10 linear or branched alkyl group, alkenyl group or oxoalkyl group, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, aralkyl or aryloxoalkyl group, or any two of ^R 1, ^{R 2} and ^{R 3} are bonded to each other 1,4 A butylene group or a 3-oxa-1,5-pentylene group may be formed, and a ring may be formed together with the sulfur atom in the formula.

In the general formula (b), R ⁴ represents a substituted or unsubstituted linear, branched or cyclic alkyl group or alkenyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 14 carbon atoms. Indicates a group. r represents an integer of 1 to 5, and q represents 0 (zero) or 1.

In the general formula (c), R ⁴ represents a substituted or unsubstituted linear, branched or cyclic alkyl group or alkenyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 14 carbon atoms. Indicates a group. r represents an integer of 1 to 5, and q represents 0 (zero) or 1. ),
A fluorine-containing N-sulfonyloxyimide compound represented by the following general formula (4):

(In the general formula (4), n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted carbon. A linear, branched or cyclic alkenyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms, Z is a single bond or a double bond. A bond, a methylene group or an oxygen atom, T and Y independently represent a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or T and Y are bonded together An aliphatic ring structure, an aromatic ring structure or a heterocyclic structure may be formed including carbon atoms).
And
Fluorine-containing oxime sulfonate compound represented by the following general formula (5)

(In the general formula (5), each n independently represents an integer of 1 to 10. R represents a substituted or unsubstituted C1-C20 linear, branched or cyclic alkyl group, substituted or non-substituted. A substituted, unsubstituted, straight chain, branched or cyclic alkenyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms, or a heteroaryl group having 4 to 15 carbon atoms, m is 0 or 1 represents m. When m is 0, p represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 15 carbon atoms, and when m is 1. P represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 15 carbon atoms, and A represents a cyano group, a trifluoromethyl group, a perfluoro group. Ethyl group, perfluoropropyl A pill group, a 5H-perfluoropentyl group, a 6H-perfluorohexyl group, a nitro group or a methyl group, and when m is 1, carbon atoms are bonded together with carbon atoms to which they are bonded to each other. (Formula 6 ring may be formed.)
Is particularly suitable because it exhibits high sensitivity to exposure to ultraviolet rays, far ultraviolet rays, extreme ultraviolet rays, electron beams, X-rays, excimer lasers, γ rays, or high energy rays of synchrotron radiation (especially excimer lasers). It is a thing.

  The present applicant has found a fluorine-containing sulfonic acid onium salt represented by the general formula [B] and a sulfonic acid group-containing compound (neutral molecule) corresponding to these, and these substances have a small number of fluorine atoms. Nevertheless, it functions as an acid generator with strong acidity, has excellent compatibility with solvents and resins, and has obtained knowledge that it is useful as an acid generator for resists. Application Nos. 2007-143879 and 2007-143880 (see Reference Examples 1 and 2 described later).

  In the general formula [B], R has the same meaning as R defined in the present invention.

  In the present invention, the “ester bond” located at the left end of the substance is further replaced with a “urethane bond”, and the basic advantage obtained in the above invention is maintained while still being applied to a solvent or resin. An acid generator having much better compatibility was provided.

  The photoacid generator of the present invention is characterized by having a urethane bond and two fluorine groups (—F) at the α-position of the sulfonate at the same time. Since the sulfonic acid onium salts of the present invention have a urethane moiety at the terminal, if there is a corresponding isocyanate, a urethane moiety having a different structure can be introduced as needed, and the performance can be freely controlled. Specifically, it is possible to appropriately adjust the boiling point of the sulfonic acid generated by introducing urethanes having a large molecular weight or bulky urethanes. Further, by introducing urethanes having high fat solubility, it is possible to freely improve the solubility in a resist solvent and the compatibility with a base resin. Furthermore, by introducing urethanes having a double bond at the terminal, it may be incorporated into the base resin by subjecting it to copolymerization with other resist monomers in some cases. It is also possible to improve the solubility with respect to a solvent, and it can contribute to the solution of the said subject.

  Furthermore, the present inventors have used the fluorine-containing sulfonate represented by the following general formula (1), which is useful as a common raw material for producing the above-mentioned photoacid generator.

(In the formula, n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 1 to 20 carbon atoms. A linear, branched or cyclic alkenyl group, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms, M ⁺ represents a lithium ion, a sodium ion, a potassium ion, (Ammonium ion or tetramethylammonium ion is shown.)
I found.

  The present inventors have also found an invention of a resist material (composition) in which any of the above-mentioned photoacid generators, a solvent, and a specific base resin are combined.

  Further, in connection with these findings, the inventors have found each invention of a method for producing a fluorinated sulfonic acid represented by the general formula (2) and a pattern forming method for a resist, and have completed the present invention.

That is, the present invention includes [Reference Invention] and [Invention 1] to [Invention 21 ].

[ Reference invention ]
A fluorine-containing sulfonate having a structure represented by the following general formula (A) or a fluorine-containing sulfonic acid group-containing compound.

(In the formula, the meanings of n, R and a are as described above.)
[Invention 1 ]
A fluorine-containing sulfonic acid onium salt represented by the following general formula (3).

(In the formula, the meanings of n, R, and Q ⁺ are as described above.)
[Invention 2 ]
A fluorine-containing N-sulfonyloxyimide compound represented by the following general formula (4).

(In the formula, the meanings of n, R, Z, T, and Y are as described above.)
[Invention 3 ]
A fluorine-containing oxime sulfonate compound represented by the following general formula (5).

(In the formula, the meanings of n, R, m, p, and A are as described above.)
[Invention 4 ]
A fluorine-containing sulfonate represented by the following general formula (1).

(In the formula, the meanings of n, R, and M ⁺ are as described above.)
[Invention 5 ]
Responds to high energy rays of ultraviolet rays, far ultraviolet rays, extreme ultraviolet rays, electron beams, X-rays, excimer lasers, γ rays, or synchrotron radiation, and generates fluorine-containing sulfonic acids represented by the following general formula (2). A chemical amplification selected from the fluorine-containing sulfonic acid onium salt shown in Invention 1, the fluorine-containing N-sulfonyloxyimide compound shown in Invention 2, and the fluorine-containing oxime sulfonate compound shown in Invention 3 Photoacid generator for resist materials.

(In the formula, the meanings of n and R are as described above.)
[Invention 6 ]
Ultraviolet, far ultraviolet, extreme ultraviolet, electron beam, X-ray, excimer laser, gamma rays, or sensitive to high energy radiation of the synchrotron radiation, according to the first aspect fluorinated onium sulfonate, according to the present invention 2 A photoacid generator for a chemically amplified resist material, comprising at least one of a fluorine-containing N-sulfonyloxyimide compound or a fluorine-containing oxime sulfonate compound according to Invention 3 .

[Invention 7 ]
The photoacid generator according to the invention 6, ultraviolet, far ultraviolet, extreme ultraviolet, electron beam, X-ray, excimer laser, gamma-ray, or comprises irradiating the high energy beam of synchrotron radiation, the invention 5 A method for producing a fluorine-containing sulfonic acid represented by the general formula (2).

[Invention 8 ]
In a resist material comprising a base resin, a photoacid generator, and a solvent, the photoacid generator is a photoacid generator that generates the fluorinated sulfonic acid represented by the general formula (2) according to the invention 5. A resist material characterized by the above.

[Invention 9 ]
A resist material comprising a base resin, a photoacid generator and a solvent, wherein the photoacid generator is the photoacid generator according to Invention 6 .

[Invention 10 ]
Base resin is olefin, fluorine-containing olefin, acrylic ester, methacrylic ester, fluorine-containing acrylic ester, fluorine-containing methacrylate ester, norbornene compound, fluorine-containing norbornene compound, styrene compound, fluorine-containing styrene compound, vinyl ether, And a polymer obtained by polymerizing one monomer selected from the group consisting of fluorine-containing vinyl ethers, or a polymer copolymer obtained by copolymerizing two or more of the above monomers. The resist material according to the invention 8 or 9 .

[Invention 11 ]
The resist material according to invention 8 or 9 , wherein the base resin is a polymer compound containing a repeating unit represented by the following general formula (6).

(In the general formula (6), R ⁵ represents a hydrogen atom, a halogen atom, an alkyl group or a fluorine-containing alkyl group, and R ⁶ represents a linear or branched alkyl group or an alkyl group having a cyclic structure. , An aromatic ring, or a composite substituent thereof, part of which may be fluorinated, R ⁷ represents a hydrogen atom, a hydrocarbon group that may contain a branch, a fluorine-containing alkyl group, an aromatic group, (A ring having an alicyclic ring, which may contain a bond of oxygen and carbonyl, and s represents an integer of 1 to 2)
[Invention 12 ]
The resist material according to invention 8 or 9, wherein the base resin is a polymer compound containing a repeating unit represented by the following general formula (7).

(In the general formula (7), R ⁵ represents a hydrogen atom, a halogen atom, a hydrocarbon group, or a fluorine-containing alkyl group, and any one of R ⁸ , R ⁹ , and R ¹⁰ is CF ₃ C (CF ₃ ) (OH) CH ₂ - group wherein the remaining two are hydrogen).
[Invention 13 ]
The resist material according to invention 8 or 9, wherein the base resin is a polymer compound containing a repeating unit represented by the following general formula (8).

(In the general formula (8), R ⁵ represents a hydrogen atom, a halogen atom, a hydrocarbon group, or a fluorine-containing alkyl group, and R ¹¹ represents a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, or perfluoroethyl group.)
[Invention 14 ]
The resist material according to invention 8 or 9, wherein the base resin is a polymer compound containing a repeating unit represented by the following general formula (9).

(In the general formula (9), R ⁵ represents a hydrogen atom, a halogen atom, a hydrocarbon group, or a fluorine-containing alkyl group, R ¹² represents a methyl group or a trifluoromethyl group, and R ¹³ represents a hydrogen atom or a carbon number. A group containing 1 to 25 linear hydrocarbon group, a branched or cyclic hydrocarbon group having 3 to 25 carbon atoms, or an aromatic hydrocarbon group having 6 to 26 carbon atoms, part of which is fluorine atom, an oxygen atom, may also include a carbonyl bond .u represents any integer of 0 to 2, t, v represents any integer of 1 to 8, satisfying the ^{v ≦ t + 2 .R 12 ~R} 13 is In the case of a plurality, R ^{12 to} R ¹³ may be the same or different.)
[Invention 15 ]
The resist material according to invention 8 or 9 , wherein the base resin contains a repeating unit represented by the following general formula (10).

(In the general formula (10), X represents any of —CH ₂ —, —O—, and —S—. W represents an integer of 2 to 6.)
[Invention 16 ]
The resist material according to invention 8 or 9 , wherein the base resin contains a repeating unit represented by the following general formula (11).

(In the general formula (11), R ⁵ represents a hydrogen atom, a halogen atom, an alkyl group or a fluorine-containing alkyl group, R ¹⁵ represents a fluorine atom or a fluorine-containing alkyl group, and J represents a divalent linking group. ¹⁴ is an acid labile protecting group represented by any one of the following general formulas (d) to (h).

In the general formula (d), R ¹⁶ is an alkyl group which may have a substituent having 1 to 4 carbon atoms, and an alicyclic hydrocarbon group which may have a substituent having 3 to 30 carbon atoms. Or the aryl group which may have a C6-C14 substituent may be represented.

In Formula ^{(e), R 16} has the same meaning as ^{R 16} in the formula (d). R ¹⁷ is a hydrogen atom, an alkyl group which may have a substituent having 1 to 4 carbon atoms, an alicyclic hydrocarbon group which may have a substituent having 3 to 30 carbon atoms, An alkoxy group optionally having 6 substituents, an alkenyl group optionally having 2 to 4 carbon atoms, and an aryl group optionally having a substituent having 6 to 14 carbon atoms Alternatively, it represents an aralkyl group which may have a substituent having 7 to 20 carbon atoms.

In the said general formula (f), R <^18> , R <^19> and R <^20> may be same or different, respectively, The alkyl group which may have a C1-C4 substituent, C3-C30 An alicyclic hydrocarbon group that may have a substituent, an alkenyl group that may have a substituent having 2 to 4 carbon atoms, or a substituent that has 6 to 14 carbon atoms It represents a good aryl group or an aralkyl group which may have a substituent having 7 to 20 carbon atoms. Two groups out of R ^{18 to} R ²⁰ may be bonded to form a ring.

In the general formula ^(g), R ^{18, R 19} and ^{R 20} have the same meanings as ^{R 18, R 19} and ^{R 20} in the general formula (f).

In formula ^{(h), R 16} has the same meaning as ^{R 16} in the formula (d). )
[Invention 17 ]
The resist material according to any one of Inventions 8 to 16 , wherein the base resin is insoluble or hardly soluble in the developer and becomes soluble in the developer by an acid.

[Invention 18 ]
The process of apply | coating the resist material of any one of invention 8 thru | or 17 on a board | substrate, the process of exposing with a high energy ray with a wavelength of 300 nm or less through a photomask after heat processing, and heat-processed as needed. And a step of developing using a developing solution.

[Invention 19 ]
The immersion lithography method uses an ArF excimer laser with a wavelength of 193 nm and inserts water or a liquid other than water having a refractive index higher than the refractive index in the air between the substrate coated with the resist material and the projection lens. The pattern forming method according to invention 18 characterized by the above.

[Invention 20 ]
Triphenylsulfonium cyclohexylcarbamic acid-2,2-difluoroethyl-sulfonate.

[Invention 21 ]
Triphenylsulfonium adamantane-1-ylcarbamic acid-2-bromo-2,2-difluoro-ethyl sulfonate.

  The sulfonic acid onium salt of the present invention has little concern about bioaccumulation and accumulation because the proportion of fluorine atoms in the structure is small, but the acidity of the acid generated by exposure is sufficiently high. Furthermore, when this onium sulfonate salt is used as a photoacid generator to form a resist material, it exhibits high performance with respect to ArF excimer laser light and excellent substrate adhesion and etching resistance. Further, by introducing a urethane bond into the structure, a photoacid generator (sulfonic acid onium salt) excellent in solubility in a resist solvent and compatibility with a resin, and a resist containing such a photoacid generator Material can be provided. Furthermore, by using such a resist material, a pattern forming method for obtaining a good pattern shape can be provided. The present invention has the excellent effects as described above.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

[Fluorine-containing sulfonate]
The fluorine-containing sulfonate useful as a common raw material compound of the photoacid generator in the present invention is represented by the following general formula (1).

(In the formula, n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 1 to 20 carbon atoms. A linear, branched or cyclic alkenyl group, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms, M ⁺ represents a lithium ion, a sodium ion, a potassium ion, (Ammonium ion or tetramethylammonium ion is shown.)
Here, as the substituent of R in the general formula (1), a linear, branched or cyclic alkoxy group having 1 to 20 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, an iodine atom), a cyano group, Hydroxy group, carboxyl group, linear, branched or cyclic alkoxycarbonyl group having 1 to 20 carbon atoms, linear, branched or cyclic alkylcarbonyloxy group having 1 to 20 carbon atoms, lactone, amino Group, amide group and the like.

  Here, R in the general formula (1) is shown more specifically, methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, sec-butyl group, isobutyl group, tert- Butyl, n-pentyl, cyclopentyl, n-hexyl, 2-ethylhexyl, cyclohexyl, n-octyl, n-decyl, n-dodecyl, 1-adamantyl, 2-adamantyl, bicyclo [2.2.1] hepten-2-yl group, 1-adamantanemethyl group, 2-adamantanemethyl group, phenyl group, 4-methoxyphenyl group, 4-tert-butylphenyl group, 4-biphenyl group, 1- A naphthyl group, 2-naphthyl group, 10-anthranyl group, 2-furanyl group, etc. are mentioned. Furthermore, examples of the substituent include an alkyl group having a polymerizable substituent such as an acryloyloxy group and a methacryloyloxy group. Specifically, a 2-methacryloyloxyethyl group, a 2-acryloyloxyethyl group, 1,1 -Bis (acryloylmethyl) ethyl and the like. In addition to the above, examples of those containing a carbonyl group, a lactone, or a hydroxyl group as a substituent include the following.

As M ⁺ in the general formula (1), lithium ion, sodium ion, potassium ion, ammonium ion, or tetramethylammonium ion was shown, but this considered the ease of synthesis and the ease of isolation of sulfonic acid. It is a thing. Other cations such as calcium ions and magnesium ions may be used and are not particularly limited as long as they can exist as stable sulfonic acids.

  When the fluorine-containing sulfonate is used as a raw material for the photoacid generator described later, R and n may be matched with R and n of the photoacid generator.

[Photoacid generator]
The photoacid generator of the present invention is a compound typified by a fluorine-containing onium salt, a fluorine-containing oxime sulfonate, or a fluorine-containing sulfonyloxyimide derived from the fluorine-containing sulfonate as a raw material. Responds to ultraviolet rays, extreme ultraviolet rays, electron beams, X-rays, excimer lasers, γ rays, or high energy rays irradiated with synchrotron radiation, and generates fluorine-containing sulfonic acid represented by the following general formula (2). It is used as a photoacid generator for an amplification resist material.

(In the formula, n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 1 to 20 carbon atoms. A linear, branched or cyclic alkenyl group, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms.)
Here, R and n in the general formula (2) are the same as R and n in the general formula (1).

  The fluorine-containing sulfonic acid represented by the general formula (2) is specifically shown below.

  Among these, n = 1 to 4 is preferable and n = 1 is particularly preferable from the viewpoints of appropriate boiling point and diffusion length and ease of synthesis. R is particularly preferably cyclohexyl, 2-norbornyl, or 1-adamantyl. That is, the following fluorine-containing sulfonic acids are particularly preferable.

[Fluorine-containing sulfonic acid onium salt]
The fluorine-containing sulfonic acid onium salt of the present invention is represented by the following general formula (3).

(In the formula, n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 1 to 20 carbon atoms. A linear, branched or cyclic alkenyl group, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms is shown.

Q ⁺ represents a sulfonium cation represented by the following general formula (a) or the following general formula (b), or an iodonium cation represented by the following general formula (c).

In the general formula (a), R ¹ , R ² and R ³ are each independently a substituted or unsubstituted C 1-10 linear or branched alkyl group, alkenyl group or oxoalkyl group, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, aralkyl or aryloxoalkyl group, or any two of ^R 1, ^{R 2} and ^{R 3} are bonded to each other 1,4 A butylene group or a 3-oxa-1,5-pentylene group may be formed, and a ring may be formed together with the sulfur atom in the formula.

In the general formula (b), R ⁴ represents a substituted or unsubstituted linear, branched or cyclic alkyl group or alkenyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 14 carbon atoms. Indicates a group. r represents an integer of 1 to 5, and q represents 0 (zero) or 1.

In the general formula (c), R ⁴ represents a substituted or unsubstituted linear, branched or cyclic alkyl group or alkenyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 14 carbon atoms. Indicates a group. r represents an integer of 1 to 5, and q represents 0 (zero) or 1. )
Hereinafter, the sulfonium cation represented by the general formula (a) and the general formula (b) and the iodonium cation represented by the general formula (c) and the general formula (d) will be described in detail.

Specific examples of R ¹ , R ² and R ³ in the general formula (a) of the sulfonium cation represented by the general formula (a) include the following. As the alkyl group, methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, sec-butyl group, isobutyl group, tert-butyl group, n-pentyl group, cyclopentyl group, n- Hexyl group, n-heptyl group, 2-ethylhexyl group, cyclohexyl group, cycloheptyl group, 4-methylcyclohexyl group, cyclohexylmethyl group, n-octyl group, n-decyl group, 1-adamantyl group, 2-adamantyl group, Bicyclo [2.2.1] hepten-2-yl group, 1-adamantanemethyl group, 2-adamantanemethyl group and the like can be mentioned. Examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, a butenyl group, a hexenyl group, and a cyclohexenyl group. Examples of the oxoalkyl group include 2-oxocyclopentyl group, 2-oxocyclohexyl group, 2-oxopropyl group, 2-oxoethyl group, 2-cyclopentyl-2-oxoethyl group, 2-cyclohexyl-2-oxoethyl group, 2- ( And 4-methylcyclohexyl) -2-oxoethyl group. As the aryl group, phenyl group, naphthyl group, thienyl group and the like, p-methoxyphenyl group, m-methoxyphenyl group, o-methoxyphenyl group, p-ethoxyphenyl group, p-tert-butoxyphenyl group, m-tert. -Alkoxyphenyl groups such as butoxyphenyl group, alkylphenyl groups such as 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, and ethylphenyl group; alkylnaphthyl groups such as methylnaphthyl group and ethylnaphthyl group; Examples thereof include a dialkylnaphthyl group such as a diethylnaphthyl group, a dialkoxynaphthyl group such as a dimethoxynaphthyl group and a diethoxynaphthyl group. Examples of the aralkyl group include a benzyl group, a 1-phenylethyl group, and a 2-phenylethyl group. As the aryloxoalkyl group, 2-aryl-2-oxoethyl group such as 2-phenyl-2-oxoethyl group, 2- (1-naphthyl) -2-oxoethyl group, 2- (2-naphthyl) -2-oxoethyl group and the like Groups and the like. When any two or more of R ¹ , R ² and R ³ are bonded to each other to form a cyclic structure via a sulfur atom, 1,4-butylene, 3-oxa-1, it is a 5-pentylene. Furthermore, aryl groups having polymerizable substituents such as an acryloyloxy group and a methacryloyloxy group can be mentioned as a substituent, specifically, 4- (acryloyloxy) phenyl group, 4- (methacryloyloxy) phenyl group, 4 -Vinyloxyphenyl group, 4-vinylphenyl group, etc. are mentioned.

More specifically, the sulfonium cation represented by the general formula (a) is represented by triphenylsulfonium, (4-tert-butylphenyl) diphenylsulfonium, bis (4-tert-butylphenyl) phenylsulfonium, tris (4-tert -Butylphenyl) sulfonium, (3-tert-butylphenyl) diphenylsulfonium, bis (3-tert-butylphenyl) phenylsulfonium, tris (3-tert-butylphenyl) sulfonium, (3,4-ditert-butylphenyl) ) Diphenylsulfonium, bis (3,4-ditert-butylphenyl) phenylsulfonium, tris (3,4-ditert-butylphenyl) sulfonium, (4-tert-butoxyphenyl) diphenylsulfonium, bi (4-tert-butoxyphenyl) phenylsulfonium, tris (4-tert-butoxyphenyl) sulfonium, (3-tert-butoxyphenyl) diphenylsulfonium, bis (3-tert-butoxyphenyl) phenylsulfonium, tris (3-tert -Butoxyphenyl) sulfonium, (3,4-ditert-butoxyphenyl) diphenylsulfonium, bis (3,4-ditert-butoxyphenyl) phenylsulfonium, tris (3,4-ditert-butoxyphenyl) sulfonium, diphenyl (4-thio-phenoxyphenyl) sulfonium, (4-tert-butoxycarbonylmethyloxyphenyl) diphenylsulfonium, (4-tert-butoxycarbonylmethyloxyphenyl) di E sulfonyl sulfonium, (4-tert-butoxyphenyl) bis (4-dimethylaminophenyl) sulfonium, tris (4-dimethylaminophenyl) sulfonium, 2-naphthyl diphenylsulfonium, dimethyl (2-naphthyl) sulfonium, (4-hydroxyphenyl ) Dimethylsulfonium, (4-methoxyphenyl) dimethylsulfonium, trimethylsulfonium, (2-oxocyclohexyl) cyclohexylmethylsulfonium, trinaphthylsulfonium, tribenzylsulfonium, diphenylmethylsulfonium, dimethylphenylsulfonium, 2-oxo-2-phenylethyl Thiacyclopentanium, diphenyl 2-thienylsulfonium, 4-n-butoxynaphthyl-1-thiacyclopentanium, 2 n- butoxynaphthyl-1-thiacyclopentanium, 4-methoxynaphthyl-1-thiacyclopentanium, 2-methoxynaphthyl-1-thiacyclopentanium, and the like. More preferably, triphenylsulfonium, (4-tert-butylphenyl) diphenylsulfonium, (4-tert-butoxyphenyl) diphenylsulfonium, tris (4-tert-butylphenyl) sulfonium, (4-tert-butoxycarbonylmethyloxyphenyl) ) Diphenylsulfonium and the like.

  Furthermore, 4- (methacryloyloxy) phenyldiphenylsulfonium, 4- (acryloyloxy) phenyldiphenylsulfonium, 4- (methacryloyloxy) phenyldimethylsulfonium, 4- (acryloyloxy) phenyldimethylsulfonium and the like can be mentioned. Regarding these polymerizable sulfonium cations, reference can be made to JP-A-4-230645 and JP-A-2005-84365.

(O) q _{- -} R ⁴ in the general formula (b) sulfonium cations general formula represented by (b) Substituents position of the base is not particularly limited, 4 or 3-position of the phenyl group are preferred. More preferably, it is the 4th position. Here, q is 0 (zero) or 1. As R ⁴ , specifically, methyl group, ethyl group, n-propyl group, sec-propyl group, cyclopropyl group, n-butyl group, sec-butyl group, iso-butyl group, tert-butyl group, n -Pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-octyl group, n-decyl group, n-dodecyl group, 1-adamantyl group, 2-adamantyl group, bicyclo [2.2.1] heptene- 2-yl group, phenyl group, 4-methoxyphenyl group, 4-tert-butylphenyl group, 4-biphenyl group, 1-naphthyl group, 2-naphthyl group, 10-anthranyl group, 2-furanyl group, and q = In the case of 1, an acryloyl group, a methacryloyl group, a vinyl group, and an allyl group are exemplified.

  Specific sulfonium cations include (4-methylphenyl) diphenylsulfonium, (4-ethylphenyl) diphenylsulfonium, (4-cyclohexylphenyl) diphenylsulfonium, (4-n-hexylphenyl) diphenylsulfonium, (4-n -Octyl) phenyldiphenylsulfonium, (4-methoxyphenyl) diphenylsulfonium, (4-ethoxyphenyl) diphenylsulfonium, (4-tert-butoxyphenyl) diphenylsulfonium, (4-cyclohexyloxyphenyl) diphenylsulfonium, (4-tri Fluoromethylphenyl) diphenylsulfonium, (4-trifluoromethyloxyphenyl) diphenylsulfonium, (4-tert-butoxycarbonylmethylo) Shifeniru) diphenyl sulfonium, and the like.

The substituent position of the R ⁴ — (O) _q — group in the iodonium cation general formula (c) represented by the general formula (c) is not particularly limited, but the 4-position or the 3-position of the phenyl group is preferable. More preferably, it is the 4th position. Here, q is 0 (zero) or 1. Specific examples of R ⁴ can be mentioned again the same as R ⁴ in formula (b).

  Specific iodonium cations include bis (4-methylphenyl) iodonium, bis (4-ethylphenyl) iodonium, bis (4-tert-butylphenyl) iodonium, bis (4- (1,1-dimethylpropyl) phenyl. ) Iodonium, (4-methoxyphenyl) phenyliodonium, (4-tert-butoxyphenyl) phenyliodonium, 4- (acryloyloxy) phenylphenyliodonium, 4- (methacryloyloxy) phenylphenyliodonium, and the like. (4-tert-butylphenyl) iodonium is preferably used.

  The sulfonic acid salt represented by the general formula (1) and the sulfonic acid onium salt represented by the general formula (3) can be produced, for example, by the method shown in the following [Formula 1].

(In the formula 1, R and n are .Q ⁺ is synonymous with R and n in the general formulas (1) and (3) the same meaning as ^{Q +} in the general formula (3) _.M 2 _S 2 O M in ₄ represents lithium, sodium, potassium , ammonium, or tetramethylammonium, and X ⁻ represents a monovalent anion.)
That is,
First step: A step of obtaining fluorinated urethane bromide (carbamate) represented by the general formula (a) by reacting ω-bromo-ω, ω-difluoroalkanol with various isocyanates.

  Second Step: The fluorinated urethane bromide (carbamate) represented by the general formula (a) obtained in the first step is sulfinized using a sulfinating agent such as dithionite to give a general formula (b The process of obtaining the fluorine-containing sulfinate shown by this.

  Third step: The fluorine-containing sulfinic acid salt represented by the general formula (b) obtained in the second step is oxidized using an oxidizing agent such as hydrogen peroxide, and the fluorine-containing sulfone represented by the general formula (1). Obtaining an acid salt.

Fourth Step: a fluorine-containing sulfonate represented by the obtained formula in the third step (1), general formula Q ⁺ X ^- in is reacted with a monovalent onium salt represented in the general formula (3) It is a production method comprising four steps of obtaining the fluorine-containing sulfonic acid onium salt shown.

As n and R of the fluorine-containing sulfonic acid onium salt, n = 1 to 4 is preferable (n = 1 is particularly preferable) similarly to the fluorine-containing sulfonic acid generated as a result of light irradiation, and R is cyclohexyl, 2-norbornyl and 1-adamantyl are particularly preferred. In this case, as Q ⁺ , triphenylsulfonium ion, (4-tert-butylphenyl) diphenylsulfonium ion, (4-tert-butoxyphenyl) diphenylsulfonium ion, tris (4-tert-butylphenyl) sulfonium ion, ( 4-tert-Butoxycarbonylmethyloxyphenyl) diphenylsulfonium ion and bis (4-tert-butylphenyl) iodonium ion are preferable, and triphenylsulfonium ion is particularly preferable. Therefore, particularly preferred fluorine-containing sulfonic acid onium salts are triphenylsulfonium cyclohexylcarbamic acid-2,2-difluoroethyl-sulfonate, triphenylsulfonium 2-norbornylcarbamic acid-2,2-difluoro-ethylsulfonate, triphenylsulfonium. Adamantan-1-ylcarbamic acid-2,2-difluoro-ethyl sulfonate. That is, the following fluorine-containing sulfonic acid onium salts are particularly preferable.

[Fluorine-containing N-sulfonyloxyimide compound]
The fluorine-containing N-sulfonyloxyimide compound of the present invention is represented by the following general formula (4).

(In the general formula (4), n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted carbon. A linear, branched or cyclic alkenyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms, Z is a single bond or a double bond. A bond, a methylene group or an oxygen atom, T and Y independently represent a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or T and Y are bonded together An aliphatic cyclic structure, an aromatic ring structure or a heterocyclic structure may be formed including carbon atoms.)
Specific examples of R include those described above. Examples of the aliphatic cyclic structure, aromatic ring structure, and heterocyclic structure formed by including T and Y together with the carbon atom to which they are bonded include those represented by the following formulas (general (Shown as the right part of equation (4)).

  Next, a method for synthesizing the fluorine-containing N-sulfonyloxyimide compound represented by the general formula (4) will be described. JP-A-2001-199955 and the like can be referred to for the synthesis method of these compounds. Specifically, first, the sulfonate represented by the general formula (1) is converted into sulfonyl chloride using phosphorus pentachloride, thionyl chloride, phosphorus oxychloride or the like.

  Next, N-hydroxydicarboximide represented by the general formula (i) which is commercially available or synthesized from the corresponding dicarboxylic acid and hydroxylamine

(In the formula, Z represents a single bond, a double bond, a methylene group or an oxygen atom, T and Y independently represent a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or T and Y. And may form an aliphatic ring structure, an aromatic ring structure or a heterocyclic structure including the carbon atom to which they are bonded.)
And the above-mentioned sulfonyl chloride are dissolved in a solvent such as THF or dichloromethane and reacted under basic conditions or in a basic solvent such as triethylamine or pyridine. A fluorine-containing N-sulfonyloxyimide compound represented by 4) can be obtained ([Formula 2]).

  Preferred n and R of the fluorine-containing N-sulfonyloxyimide compound are the same as those of the fluorine-containing sulfonic acid onium salt. In this case, the “right side part of the formula (4)” is particularly preferably the following structure.

[Fluorine-containing oxime sulfonate compound]
The fluorine-containing oxime sulfonate compound of the present invention is represented by the following general formula (5).

(In the general formula (5), n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted carbon. A linear, branched or cyclic alkenyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms, or a heteroaryl group having 4 to 15 carbon atoms, m is 0 or 1. , When m is 0, p represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 15 carbon atoms. Represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 15 carbon atoms, A being a cyano group, a trifluoromethyl group, a perfluoroethyl group, Perfluoropropyl group, 5H A perfluoropentyl group, 6H-perfluorohexyl group, nitro group or methyl group, and when m is 1, each A is bonded to each other to form a ring having 6 carbon atoms together with the carbon atom to which they are bonded. It may be formed.)
Specific examples of R include those described above. As for the skeleton of these oxime sulfonates, for example, those described in International Publication No. 2004/074242 can be referred to.

  A more specific oxime sulfonate skeleton excluding the sulfonic acid moiety is shown below.

  Next, a method for synthesizing the oxime sulfonate compound represented by the general formula (5) will be described. The method for synthesizing these compounds can be referred to the aforementioned patent documents. Specifically, first, the sulfonate represented by the general formula (1) is converted into sulfonyl chloride using phosphorus pentachloride, thionyl chloride, phosphorus oxychloride or the like.

  Next, an oxime represented by the general formula (ii) that is commercially available or synthesized from a corresponding ketone and hydroxylamine

(In the formula, m represents 0 or 1, and when m is 0, p represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 15 carbon atoms. And when n is 1, p represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 15 carbon atoms, and A represents a cyano group. , Trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, 5H-perfluoropentyl group, 6H-perfluorohexyl group, nitro group or methyl group, when n is 1, And may form a 6-carbon ring together with the carbon atoms to which they are attached.)
The above-mentioned sulfonyl chloride can be dissolved in a solvent such as THF or dichloromethane and reacted under basic conditions or in a basic solvent such as triethylamine or pyridine ([Formula 3] ]).

  Preferred n and R of the fluorine-containing oxime sulfonate compound are the same as those of the fluorine-containing sulfonic acid onium salt. In this case, A is particularly preferably a cyano group or a trifluoromethyl group, m is preferably 0, and when m is 0, p preferably has the following structure.

[Photoacid generator for chemically amplified resist materials]
As described above, the fluorine-containing sulfonic acid represented by the general formula (2) of the present invention includes the fluorine-containing sulfonic acid onium salt represented by the general formula (3) and the fluorine-containing N-sulfonyl represented by the general formula (4). High energy of irradiation with ultraviolet rays, far ultraviolet rays, extreme ultraviolet rays, electron beams, X-rays, excimer lasers, γ rays, or synchrotron radiation for oxyimide compounds or fluorine-containing oxime sulfonate compounds represented by the general formula (5) It can be generated by irradiating a line or the like ([Equation 4]).

  Accordingly, the fluorine-containing sulfonic acid onium salt represented by the general formula (3), the fluorine-containing N-sulfonyloxyimide compound represented by the general formula (4) or the fluorine-containing oxime sulfonate compound represented by the general formula (5) It can be used as an acid generator.

The photoacid generator of the present invention is represented by the fluorine-containing sulfonic acid onium salt represented by the general formula (3), the fluorine-containing N-sulfonyloxyimide compound represented by the general formula (4), or the general formula (5). A fluorine-containing oxime sulfonate compound is contained as an active ingredient. The photoacid generator of the present invention forms a photosensitive resin composition (resist material) by mixing with a resin (photosensitive resin) whose solubility in an alkaline developer is changed by the action of an acid, and is used. be able to. {Generally, the above-mentioned fluorine-containing sulfonic acid onium salt alone (solid) is used as a “photoacid generator” alone or in combination with other photoacid generators in a photosensitive resin. }
If the said high molecular compound is illustrated, the photo-acid generator by this invention will receive irradiation of light or an active energy ray as a 1st example, and the photoacid generator by this invention will turn into a strong acid (fluorine-containing sulfonic acid shown by General formula (2)). A positive resist that changes to a polymer compound having an acidic unit soluble in a developer such as carboxylic acid, phenol, or hexafluoroalcohol, when the protective group of the polymer side chain is removed by the action of the strong acid, As a second example, the photoacid generator according to the present invention is transferred to a strong acid upon irradiation with light or an electron beam, and reacts with a crosslinking agent in which the functional group of the polymer side chain is premixed by the action of the strong acid. Thus, it can be applied to a wide variety of photosensitive compositions such as a negative resist which is insoluble in a developer.

  Next, the resist material of the present invention will be described. The resist material of the present invention comprises a base resin, a photoacid generator, and a solvent. In addition to these, additives such as a basic compound, a dissolution inhibitor, and a crosslinking agent are added as necessary. It can also be added.

  The photoacid generator contained in the resist material of the present invention is as described above, and the blending amount thereof is preferably in the range of 0.1 to 15 parts by weight with respect to 100 parts by weight of the base resin, and more preferably. Can be added in the range of 1 to 10 parts by weight.

[Base resin]
Next, the base resin blended in the resist material according to the present invention will be described. As the base resin, a repeating unit which does not contain an aromatic substituent is preferably used. Olefin, fluorine-containing olefin, acrylic ester, methacrylic ester, fluorine-containing acrylic ester, fluorine-containing methacrylate, norbornene compound, fluorine-containing A polymer obtained by polymerizing one kind of monomer selected from the group consisting of a norbornene compound, a styrene compound, a fluorine-containing styrene compound, vinyl ether, and a fluorine-containing vinyl ether, or two or more of the monomers The polymer is preferably a copolymer obtained by copolymerization of

  Examples of the olefin include ethylene and propylene, and examples of the fluoroolefin include vinyl fluoride, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, and hexafluoroisobutene.

  Further, as the acrylic ester or methacrylic ester, it can be used without particular limitation for the ester side chain. However, if a known compound is exemplified, methyl acrylate or methacrylate, ethyl acrylate or methacrylate, n-propyl acrylate or methacrylate, Isopropyl acrylate or methacrylate, n-butyl acrylate or methacrylate, isobutyl acrylate or methacrylate, n-hexyl acrylate or methacrylate, n-octyl acrylate or methacrylate, 2-ethylhexyl acrylate or methacrylate, lauryl acrylate or methacrylate, 2-hydroxyethyl acrylate or methacrylate 2-hydroxypropyl acrylate or methacrylate Such as acrylic acid or alkyl ester of methacrylic acid, ethylene glycol, propylene glycol, acrylate or methacrylate containing tetramethylene glycol group, acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, diacetone acrylamide, etc. Unsaturated amide, acrylonitrile, methacrylonitrile, alkoxysilane-containing vinylsilane, acrylic acid or methacrylic acid ester, t-butyl acrylate or methacrylate, 3-oxocyclohexyl acrylate or methacrylate, adamantyl acrylate or methacrylate, alkyladamantyl acrylate or methacrylate, cyclohexyl Acrylate or methacrylate, tri Black decanyl acrylate or methacrylate, acrylate or methacrylate having a ring structure such as lactone ring or norbornene ring, acrylic acid, methacrylic acid, and the like. Furthermore, it is also possible to use maleic acid, fumaric acid, maleic anhydride, etc. as the above acrylate compounds containing α cyano group or similar compounds.

  In addition, as fluorine-containing acrylic ester and fluorine-containing methacrylate ester, a group having a fluorine atom is an acrylic ester or methacrylic ester having an α-position or an ester site of acrylic, and a cyano group is introduced at the α-position May be. For example, the monomer having a fluorine-containing alkyl group introduced at the α-position is the above-mentioned non-fluorinated acrylic acid ester or methacrylic acid ester, and the α-position is a trifluoromethyl group, trifluoroethyl group, nonafluoro- A monomer provided with an n-butyl group or the like is preferably employed.

  On the other hand, the ester moiety is a perfluoroalkyl group, a fluoroalkyl group that is a fluoroalkyl group, or a unit in which an ester moiety coexists with a cyclic structure and fluorine, and the cyclic structure is substituted with, for example, fluorine or a trifluoromethyl group Acrylic acid ester or methacrylic acid ester having a unit having a fluorine-containing benzene ring, a fluorine-containing cyclopentane ring, a fluorine-containing cyclohexane ring, a fluorine-containing cycloheptane ring or the like. An ester of acrylic acid or methacrylic acid in which the ester moiety is a fluorine-containing t-butyl ester group can also be used. Among such units, particularly representative ones are exemplified in the form of monomers, 2,2,2-trifluoroethyl acrylate, 2,2,3,3-tetrafluoropropyl acrylate, 1,1 , 1,3,3,3-hexafluoroisopropyl acrylate, heptafluoroisopropyl acrylate, 1,1-dihydroheptafluoro-n-butyl acrylate, 1,1,5-trihydrooctafluoro-n-pentyl acrylate, 1, 1,2,2-tetrahydrotridecafluoro-n-octyl acrylate, 1,1,2,2-tetrahydroheptadecafluoro-n-decyl acrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3 , 3-Tetrafluoropropyl methacrylate, 1,1,1,3,3,3-hexafluo Isopropyl methacrylate, heptafluoroisopropyl methacrylate, 1,1-dihydroheptafluoro-n-butyl methacrylate, 1,1,5-trihydrooctafluoro-n-pentyl methacrylate, 1,1,2,2-tetrahydrotridecafluoro- Examples include n-octyl methacrylate, 1,1,2,2-tetrahydroheptadecafluoro-n-decyl methacrylate, perfluorocyclohexylmethyl acrylate, perfluorocyclohexylmethyl methacrylate, and the like.

  The norbornene compound and the fluorine-containing norbornene compound are norbornene monomers having a single nucleus or a plurality of nucleus structures, and these can be used without any particular limitation. In this case, allyl alcohol, fluorine-containing allyl alcohol, acrylic acid, α-fluoroacrylic acid, methacrylic acid, all acrylic acid esters or methacrylic acid esters described herein, fluorine-containing acrylic acid esters or methacrylic acid esters, etc. A norbornene compound obtained by performing a Diels Alder addition reaction using a saturated compound, cyclopentadiene, and cyclohexadiene is preferably used.

  Furthermore, styrene compounds, fluorine-containing styrene compounds, vinyl ethers, fluorine-containing vinyl ethers, allyl ethers, vinyl esters, vinyl silanes, and the like can also be used. Here, styrene compounds and fluorine-containing styrene compounds include styrene, fluorinated styrene, hydroxystyrene, styrene compounds to which hexafluoroacetone is added, styrene or hydroxystyrene substituted with hydrogen by a trifluoromethyl group, α The above-mentioned styrene or fluorine-containing styrene compound having a halogen, an alkyl group or a fluorine-containing alkyl group bonded to the position can be used. On the other hand, vinyl ether, fluorine-containing vinyl ether, allyl ether, vinyl ester and the like can also be used. For example, alkyl vinyl ether which may contain a hydroxy group such as a methyl group, an ethyl group, a hydroxyethyl group or a hydroxybutyl group. In addition, part or all of the hydrogen may be substituted with fluorine. Further, cyclohexyl vinyl ether, cyclic vinyl ether having hydrogen or carbonyl bond in its cyclic structure, or a monomer in which part or all of hydrogen of the cyclic vinyl ether is substituted with fluorine can be used. Allyl ether, vinyl ester, and vinyl silane can be used without particular limitation as long as they are known compounds.

  Among the above-described base resins, a base resin containing a repeating unit represented by the following general formula (6) is preferably used.

In the general formula (6), R ⁵ represents a hydrogen atom, a halogen atom, a hydrocarbon group, or a fluorine-containing alkyl group, and R ⁶ represents a linear or branched alkyl group or an alkyl group having a cyclic structure. , An aromatic ring, or a composite substituent thereof, part of which may be fluorinated. R ⁷ is a cyclic group having a hydrogen atom, a hydrocarbon group which may contain a branch, a fluorine-containing alkyl group, an aromatic or an alicyclic ring, and may contain a bond of oxygen and carbonyl. Moreover, s represents the integer of 1-2.

R ⁵ that can be used in the general formula (6) can be used without particular limitation as long as it is a hydrogen atom, a halogen atom, a hydrocarbon group, or a fluorine-containing alkyl group. Examples of preferred substituents include fluorine, chlorine, bromine and the like as halogen atoms, and methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl as hydrocarbon groups. Examples thereof include a group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a benzyl group, a phenethyl group, etc., and further a fluorine-containing alkyl group in which part or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. However, in the case of a hydrocarbon group and a fluorine-containing alkyl group, about 1 to 20 carbon atoms are preferable, and further 1 to 4 carbon atoms are suitably employed from the viewpoint of polymerizability. In particular, if a fluorine-containing alkyl group is exemplified, the trifluoromethyl group of —CF ₃ , the trifluoroethyl group of —CH ₂ CF ₃ , 1,1,1,3,3,3-hexafluoroisopropyl group, heptafluoro Examples thereof include an isopropyl group and a —C ₄ F ₉ nonafluoro-n-butyl group.

R ^{6 which} can be used in the general formula (6) is an alkyl group which may have a straight chain or a branched chain, an alkyl group having a cyclic structure, an aromatic ring, or a composite substituent thereof, and a part thereof May be fluorinated or may contain an unsaturated bond. For example, linear or branched alkylene groups such as methylene, ethylene, isopropylene, t-butylene, cyclic structures containing cyclobutene, cyclohexane, norbornene, adamantane groups, phenyl groups, etc. Can do. Among the structures represented by the general formula (6), as a particularly preferable structure, repeating units represented by the following general formulas (7) to (9) can be exemplified.

In the general formula (7), ^{R 5} has the same meaning as ^{R 5} in the general formula (6). Any one of R ⁸ , R ⁹ and R ¹⁰ is a CF ₃ C (CF ₃ ) (OH) CH ₂ — group, and the remaining two are hydrogen. In the general formula (8), ^{R 5} has the same meaning as ^{R 5} in the general formula (6). R ¹¹ represents a hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, or Perfluoroethyl group. In the general formula (9), ^{R 5} has the same meaning as ^{R 5} in the general formula (6). R ¹² represents a methyl group or a trifluoromethyl group, R ¹³ is a group containing a hydrogen atom, a linear, branched or cyclic hydrocarbon group having 1 to 25 carbon atoms or an aromatic hydrocarbon group, Some of them may contain a fluorine atom, an oxygen atom, or a carbonyl bond. u represents an arbitrary integer of 0 to 2, t, v represents an arbitrary integer of 1 to 8, and satisfies v ≦ t + 2. When R ¹² to R ¹³ are a ^plurality, R 12 ^{to R 13} may be the same or different.

Examples of the linear, branched or cyclic hydrocarbon group or aromatic hydrocarbon group having 1 to 25 carbon atoms that can be used for R ¹³ in the general formula (9) include a methyl group, an ethyl group, a propyl group, an isopropyl group, Cyclopropyl group, n-propyl group, sec-butyl group, tert-butyl group, n-pentyl group, cyclopentyl group, sec-pentyl group, neopentyl group, hexyl group, cyclohexyl group, ethylhexyl group, norbornyl group, adamantyl group Groups, vinyl groups, allyl groups, butenyl groups, pentenyl groups, ethynyl groups, phenyl groups, benzyl groups, 4-methoxybenzyl groups, etc., even if some or all of the above functional groups are substituted with fluorine atoms Good. Examples of those containing an oxygen atom include an alkoxycarbonyl group, an acetal group, and an acyl group. Examples of the alkoxycarbonyl group include a tert-butoxycarbonyl group, a tert-amyloxycarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group, An i-propoxycarbonyl group etc. can be illustrated. As acetal group, methoxymethyl group, methoxyethoxymethyl group, ethoxyethyl group, butoxyethyl group, cyclohexyloxyethyl group, benzyloxyethyl group, phenethyloxyethyl group, ethoxypropyl group, benzyloxypropyl group, phenethyloxypropyl group And cyclic ethers such as chain ether of ethoxybutyl group and ethoxyisobutyl group, tetrahydrofuranyl group and tetrahydropyranyl group. As the acyl group, acetyl group, propionyl group, butyryl group, heptanoyl group, hexanoyl group, valeryl group, pivaloyl group, isovaleryl group, lauryl group, myristoyl group, palmitoyl group, stearoyl group, oxalyl group, malonyl group, succinyl group, Glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacoyl group, acryloyl group, propioroyl group, methacryloyl group, crotonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconoyl group, canholoyl group, benzoyl group, phthaloyl group Group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group, cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group, isonicotinoyl group And the like can be given. Furthermore, what substituted a part or all of the hydrogen atom of the said substituent by the fluorine atom can also be used.

  On the other hand, in addition to the base resin containing the repeating unit represented by the general formula (6) described above, a base resin containing a repeating unit represented by the following general formula (10) is also preferably used.

In the general formula (10), X represents any of —CH ₂ —, —O—, and —S—. w represents an integer of 2-6.

  Further, in addition to the base resin containing the repeating unit represented by the general formula (6) or the general formula (10) described above, a base resin containing a repeating unit represented by the following general formula (11) is also preferably used. .

(In the general formula (11), ^{.R 14 R 5} are the same as ^{R 5} in the general formula (6) ^{.R 15} is fluorine atom or fluorine-containing alkyl group, J is the divalent linking group is represented by the following It is an acid labile protecting group represented by any one of the general formulas (d) to (h).

In the general formula (d), R ¹⁶ is an alkyl group which may have a substituent having 1 to 4 carbon atoms, and an alicyclic hydrocarbon group which may have a substituent having 3 to 30 carbon atoms. Or the aryl group which may have a C6-C14 substituent may be represented.

In Formula ^{(e), R 16} has the same meaning as ^{R 16} in the formula (d). R ¹⁷ is a hydrogen atom, an alkyl group which may have a substituent having 1 to 4 carbon atoms, an alicyclic hydrocarbon group which may have a substituent having 3 to 30 carbon atoms, An alkoxy group optionally having 6 substituents, an alkenyl group optionally having 2 to 4 carbon atoms, and an aryl group optionally having a substituent having 6 to 14 carbon atoms Alternatively, it represents an aralkyl group which may have a substituent having 7 to 20 carbon atoms.

In the said general formula (f), R <^18> , R <^19> and R <^20> may be same or different, respectively, The alkyl group which may have a C1-C4 substituent, C3-C30 An alicyclic hydrocarbon group that may have a substituent, an alkenyl group that may have a substituent having 2 to 4 carbon atoms, or a substituent that has 6 to 14 carbon atoms It represents a good aryl group or an aralkyl group which may have a substituent having 7 to 20 carbon atoms. Two groups out of R ^{18 to} R ²⁰ may be bonded to form a ring.

In the general formula ^(g), R ^{18, R 19} and ^{R 20} have the same meanings as ^{R 18, R 19} and ^{R 20} in the general formula (f).

In formula ^{(h), R 16} has the same meaning as ^{R 16} in the formula (d). )
In the general formulas (d) to (h) described above, R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and R ²⁰ represent a monovalent organic group described below. Among these, (d), (e), and (f) function as a chemically amplified type, and therefore are particularly preferable for use as a resist composition applied to a pattern forming method in which exposure is performed with high energy rays.

R ¹⁶ represents an alkyl group, an alicyclic hydrocarbon group or an aryl group. R ¹⁷ represents a hydrogen atom, an alkyl group, an alicyclic hydrocarbon group, an alkenyl group, an aralkyl group, an alkoxy group or an aryl group. R ¹⁸ , R ¹⁹ and R ²⁰ may be the same or different and each represents an alkyl group, an alicyclic hydrocarbon group, an alkenyl group, an aralkyl group or an aryl group. Two groups out of R ^{18 to} R ²⁰ may be bonded to form a ring.

  Here, as the alkyl group, those having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group are preferable, and alicyclic Examples of the hydrocarbon group include those having 3 to 30 carbon atoms, specifically, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group, tricyclodecanyl group, dicyclohexane. Those having 3 to 30 carbon atoms such as pentenyl group, norbornane epoxy group, menthyl group, isomenthyl group, neomenthyl group, tetracyclododecanyl group and steroid residue are preferable, and the alkenyl group is vinyl group, propenyl group, allyl group. Group having 2 to 4 carbon atoms such as butenyl group is preferable, and aryl group is phenyl group, xylyl group, toluyl group. , Cumenyl group, naphthyl group preferably has the number of 6 to 14 carbon such as anthracenyl group, which may have a substituent. Examples of the aralkyl group include those having 7 to 20 carbon atoms, which may have a substituent. Examples include a benzyl group, a phenethyl group, and a cumyl group.

  In addition, examples of the substituent further included in the organic group include a hydroxyl group, a halogen atom (fluorine, chlorine, bromine, iodine), a nitro group, a cyano group, the alkyl group or alicyclic hydrocarbon group, a methoxy group, and an ethoxy group. Group, hydroxyethoxy group, propoxy group, hydroxypropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, alkoxy group such as tert-butoxy group, alkoxycarbonyl group such as methoxycarbonyl group, ethoxycarbonyl group, benzyl group An aralkyl group such as a phenethyl group and a cumyl group, an aralkyloxy group, a formyl group, an acetyl group, a butyryl group, a benzoyl group, a cyanamyl group, an acyl group such as a valeryl group, an acyloxy group such as a butyryloxy group, the above alkenyl group, vinyloxy Group, propenyloxy group, allyloxy group, buteni Alkenyloxy groups such as oxy group, the aryl group, an aryloxy group such as phenoxy group, and an aryloxycarbonyl group such as benzoyloxy group.

  Moreover, the lactone group shown by the following general formula (11-1) and general formula (11-2) is mentioned.

In the formulas, R ^a represents 1-4 alkyl group or a perfluoroalkyl group having a carbon number. Each R ^b independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a perfluoroalkyl group, a hydroxy group, a carboxylic acid group, an alkyloxycarbonyl group, an alkoxy group, or the like. n represents an integer of 1 to 4.

  Next, the acid labile protecting group will be specifically shown.

Examples of the alkoxycarbonyl group represented by R ¹⁶ —O—C (═O) — include a tert-butoxycarbonyl group, a tert-amyloxycarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group, an i-propoxycarbonyl group, Examples thereof include a cyclohexyloxycarbonyl group, an isobornyloxycarbonyl group, an adamantaneoxycarbonyl group and the like.

Examples of the acetal group represented by R ¹⁶ —O—CHR ¹⁷ — include a methoxymethyl group, an ethoxymethyl group, a 1-ethoxyethyl group, a 1-butoxyethyl group, a 1-isobutoxyethyl group, and a cyclohexyloxyethyl group. Benzyloxyethyl group, phenethyloxyethyl group, ethoxypropyl group, benzyloxypropyl group, phenethyloxypropyl group, ethoxybutyl group, 1-cyclohexyloxyethyl group, ethoxyisobutyl group, methoxyethoxymethyl group, tetrahydropyranyl group, Examples include a tetrahydrofuranyl group. Moreover, the acetal group obtained by adding vinyl ethers with respect to a hydroxyl group can be mentioned.

The tertiary hydrocarbon group represented by CR ¹⁸ R ¹⁹ R ²⁰ — includes a tert-butyl group, a tert-amyl group, a 1,1-dimethylpropyl group, a 1-ethyl-1-methylpropyl group, 1 , 1-dimethylbutyl group, 1-ethyl-1-methylbutyl group, 1,1-diethylpropyl group, 1,1-dimethyl-1-phenylmethyl group, 1-methyl-1-ethyl-1-phenylmethyl group, 1,1-diethyl-1-phenylmethyl group, methylcyclohexyl group, ethylcyclohexyl group, methylcyclopentyl group, ethylcyclopentyl group, isobornyl group, methyladamantyl group, ethyladamantyl group, isopropyladamantyl group, isopropylnorbornyl group, isopropyl -(4'-methylcyclohexyl) group etc. can be illustrated.

  Next, specific examples of the acid labile protecting group containing an alicyclic hydrocarbon group or an alicyclic hydrocarbon group are shown.

In the formulas (11-3) and (11-4), the methyl group (CH ₃ ) may independently be an ethyl group. In addition, as described above, one or more of the ring carbons may have a substituent.

Examples of the silyl group represented by SiR ¹⁸ R ¹⁹ R ²⁰ — include, for example, trimethylsilyl group, ethyldimethylsilyl group, methyldiethylsilyl group, triethylsilyl group, i-propyldimethylsilyl group, methyldi-i-propylsilyl. Groups, tri-i-propylsilyl group, tert-butyldimethylsilyl group, methyldi-tert-butylsilyl group, tri-tert-butylsilyl group, phenyldimethylsilyl group, methyldiphenylsilyl group, triphenylsilyl group, etc. it can.

Examples of the acyl group represented by R ¹⁶ —C (═O) — include acetyl group, propionyl group, butyryl group, heptanoyl group, hexanoyl group, valeryl group, pivaloyl group, isovaleryl group, laurylyl group, myristoyl group, Palmitoyl group, stearoyl group, oxalyl group, malonyl group, succinyl group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacoyl group, acryloyl group, propioroyl group, methacryloyl group, crotonoyl group, oleoyl group, maleoyl Group, fumaroyl group, mesaconoyl group, camphoroyl group, benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group, cinnamoyl group, furoyl group, tenoyl group , Nicotinoyl group, isonicotinoyl group and the like. Furthermore, those in which some or all of the hydrogen atoms of these acid labile group protecting groups are substituted with fluorine atoms can also be used.

  Moreover, the acid labile protecting group containing a lactone group is exemplified by the following formulas (11-5) to (11-10).

In the formulas (11-5) to (11-10), the methyl group (CH ₃ ) may be independently an ethyl group.

  When an ArF excimer laser is used as a light source for exposure, the acid labile protecting group includes tertiary alkyl groups such as tert-butyl group and tert-amyl group, 1-ethoxyethyl group, 1-butoxyethyl group 1-alkoxyethyl groups such as 1-isobutoxyethyl group and 1-cyclohexyloxyethyl group, alkoxymethyl groups such as 1-methoxymethyl group and 1-ethoxymethyl group, and the adamantyl group and isobornyl group Preferred examples thereof include an alicyclic hydrocarbon group, an acid labile protecting group containing an alicyclic hydrocarbon group, and a lactone.

The linking group J in the general formula (11) is a single bond, — (CR ²¹ R ²² ) n— (n represents an integer of 1 to 10), —O—, —C (═O) —, —C. (═O) O— or —O—C (═O) —, a thioether group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination thereof. It is a divalent linking group.

Among these, as the linking group J obtained by combining,
_{^{- (CR 21 R 22) m}} -C (= O) -O- (CR 21 R 22) n -
-(CR ²¹ R ²² ) _m -O- (CR ²¹ R ²² ) _n-
Etc. Here, m and n represent an integer of 0 to 10, m is preferably 0, and n is preferably 1.

Of these, the monovalent organic groups represented by R ²¹ and R ²² of each substituted methylene group are not particularly limited, but include a hydrogen atom, a hydroxyl group or an alkyl group, an alicyclic hydrocarbon group, a substituted alkyl group, an alkoxy group. A monovalent organic group having 1 to 30 carbon atoms selected from a group, an aryl group, and a condensed polycyclic aromatic group, and these monovalent organic groups are a fluorine atom, an oxygen atom, a sulfur atom, and a nitrogen atom May have a carbon-carbon double bond, and they may be the same or different. R ²¹ and R ²² may be combined to form a ring, and this ring is preferably an alicyclic hydrocarbon group.

  As an alkyl group, it is a C1-C30 thing and a C1-C12 thing is preferable. For example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 1-methylpropyl group, 2-methylpropyl group, tert-butyl group, n-pentyl group, i-pentyl group, 1,1-dimethylpropyl group, 1-methylbutyl group, 1,1-dimethylbutyl group, n-hexyl group, n-heptyl group, i-hexyl group, n-octyl group, i-octyl group, 2-ethylhexyl group N-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group and the like, and methyl group, ethyl group, n-propyl group, i-propyl group and the like are particularly preferable. Can do. As a substituent of the substituted alkyl group, one or more hydrogen atoms of the substituent is an alkoxy group having 1 to 4 carbon atoms, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), acyl Group, an acyloxy group, a cyano group, a hydroxyl group, a carboxy group, an alkoxycarbonyl group, a nitro group, and the like, and those substituted with a fluorine atom are preferable. Specifically, a trifluoromethyl group, a pentafluoroethyl group, 2 , 2,2-trifluoroethyl group, n-heptafluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, 3,3,3-trifluoropropyl group, hexafluoroisopropyl group, etc. be able to.

  Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

  As an aryl group, it is a C1-C30 thing. Monocyclic groups are preferably those having 3 to 12 ring carbon atoms, and more preferably those having 3 to 6 ring carbon atoms. For example, phenyl group, biphenyl group, terphenyl group, o-tolyl group, m-tolyl group, p-tolyl group, p-hydroxyphenyl group, p-methoxyphenyl group, mesityl group, o-cumenyl group, 2, 3 -Xylyl group, 2,4-xylyl group, 2,5-xylyl group, 2,6-xylyl group, 3,4-xylyl group, 3,5-xylyl group, o-fluorophenyl group, m-fluorophenyl group P-fluorophenyl group, o-trifluoromethylphenyl group, m-trifluoromethylphenyl group, p-trifluoromethylphenyl group, 2,3-bistrifluoromethyl group, 2,4-bistrifluoromethyl group, 2 , 5-bistrifluoromethyl group, 2,6-bistrifluoromethyl group, 3,4-bistrifluoromethyl group, 3,5-bistrifluoromethyl group p- chlorophenyl group, p- bromophenyl group, and a p- iodophenyl group.

  As the condensed polycyclic aromatic ring group having 1 to 30 carbon atoms, pentalene, indene, naphthalene, azulene, heptalene, biphenylene, indacene, acenaphthylene, fluorene, phenalene, phenanthrene, anthracene, fluoranthene, aceto Monovalent including phenanthrylene, aseantrylene, triphenylene, pyrene, chrysene, naphthacene, picene, perylene, pentaphen, pentacene, tetraphenylene, hexaphene, hexacene, rubicene, coronene, trinaphthylene, heptaphene, heptacene, pyranthrene, ovalen, etc. Organic groups can be mentioned, and those in which one or more hydrogen atoms are substituted with a fluorine atom, an alkyl group having 1 to 4 carbon atoms or a fluorine-containing alkyl group are preferred. It can gel.

  Examples of the monocyclic or polycyclic heterocyclic group having 3 to 25 ring atoms include pyridyl group, furyl group, thienyl group, pyranyl group, pyrrolyl group, thiantenyl group, pyrazolyl group, isothiazolyl group, isoxazolyl group, Pyrazinyl group, pyrimidinyl group, pyridazinyl group, tetrahydropyranyl group, tetrahydrofuranyl group, tetrahydrothiopyranyl group, tetrahydrothiofuranyl group, 3-tetrahydrothiophene-1,1-dioxide group and the like and atoms constituting these rings And a heterocyclic group in which one or more hydrogen atoms are substituted with an alkyl group, an alicyclic hydrocarbon group, an aryl group, or a heterocyclic group. Of these, those having a monocyclic or polycyclic ether ring or lactone ring are preferred.

The alicyclic hydrocarbon group in R ²¹ and R ²² constituting the linking group J or the alicyclic hydrocarbon group formed including the carbon atom to which they are bonded may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 3 or more carbon atoms. The number of carbon atoms is preferably 3 to 30, and particularly preferably 3 to 25 carbon atoms. These alicyclic hydrocarbon groups may have a substituent.

  As the monocyclic group, those having 3 to 12 ring carbon atoms are preferable, and those having 3 to 7 ring carbon atoms are more preferable. For example, preferred are cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecanyl group, cyclododecanyl group, tricyclodecanyl group, 4-tert-butylcyclohexyl group. Can do. Examples of the polycyclic group include an adamantyl group having 7 to 15 ring carbon atoms, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, and a cedrol group. The alicyclic hydrocarbon group may be a spiro ring, and is preferably a C 3-6 spiro ring. An adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, a cyclododecanyl group, a tricyclodecanyl group and the like are preferable. One or more of the ring carbons of these organic groups or hydrogen atoms of the linking group are each independently the above alkyl group or substituted alkyl group having 1 to 25 carbon atoms, hydroxyl group, alkoxy group, carboxyl group, alkoxycarbonyl group. Alternatively, those in which one or more hydrogen atoms thereof are substituted with a fluorine atom or a trifluoromethyl group can be exemplified.

  Here, the alkyl group is preferably a methyl group, ethyl group, propyl group, isopropyl group, butyl group or the like (referred to as “lower alkyl group” in the present specification), more preferably a methyl group, an ethyl group, or a propyl group. And an alkyl group selected from the group consisting of an isopropyl group. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom, and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, and an isopropoxycarbonyl group.

Specifically, the linking group J is
-O-
-C (= O) -O-
—CH ₂ —O—
—O—CH ₂ —
—CH ₂ —C (═O) —O—
-C (= O) -O-CH 2 -
—CH ₂ —O—CH ₂ —
—CH ₂ —C (═O) —O—CH ₂ —
Etc., and, -C (= O) -O- CR 21 R 22 - is R ²¹ and R ²² are each independently a hydrogen atom of a fluorine atom, an alkyl group, a substituted alkyl group, an alicyclic hydrocarbon group Can be mentioned as preferred. Among these, a group in which R ²¹ and R ²² are each independently a hydrogen atom or a lower alkyl group among —C (═O) —O—CR ²¹ R ²² — can be further preferred.

R ¹⁵ is a fluorine atom or a fluorine-containing alkyl group. Such a fluorine-containing alkyl group is not particularly limited, but has 1 to 12 carbon atoms, preferably 1 to 3 carbon atoms, trifluoromethyl group, pentafluoroethyl group, 2,2,2 -Trifluoroethyl group, n-heptafluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, 3,3,3-trifluoropropyl group, hexafluoroisopropyl group and the like can be mentioned. R ³ is more preferably a fluorine atom or a trifluoromethyl group.

  The molecular weight of the base resin is preferably a polymer compound having the above-described repeating unit and having a weight average molecular weight of 1,000 to 1,000,000. When the molecular weight is smaller than this, the mechanical strength and film formability are not sufficient, and when the molecular weight is larger than this, the solvent solubility and moldability are not preferable. Also, two or more of the above polymer polymers can be blended.

  In order to prepare a resist material in a chemically amplified positive type, a base resin that is insoluble or hardly soluble in a developer (usually an alkali developer) and becomes soluble in a developer by an acid is used. Therefore, those having an acid labile group that can be cleaved by an acid are used.

  In the base resin containing a repeating unit having an acid labile group, a polymerizable monomer having an acid labile group is blended with the polymerizable monomer producing the above repeating unit, and copolymerized. Or a part of the base resin containing the above-mentioned repeating unit is converted into an acid labile group. As an example of the acid labile group, any group that can be eliminated due to the effect of the above-described photoacid generator can be used without particular limitation. Specific examples include an alkoxycarbonyl group, an acetal group, a silyl group, and an acyl group. Examples of the alkoxycarbonyl group include a tert-butoxycarbonyl group, a tert-amyloxycarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group, and an i-propoxycarbonyl group. As an acetal group, methoxymethyl group, ethoxyethyl group, butoxyethyl group, cyclohexyloxyethyl group, benzyloxyethyl group, phenethyloxyethyl group, ethoxypropyl group, benzyloxypropyl group, phenethyloxypropyl group, ethoxybutyl group, An ethoxyisobutyl group etc. are mentioned. An acetal group in which vinyl ether is added to a hydroxyl group can also be used. Examples of the silyl group include trimethylsilyl group, ethyldimethylsilyl group, methyldiethylsilyl group, triethylsilyl group, i-propyldimethylsilyl group, methyldi-i-propylsilyl group, tri-i-propylsilyl group, and t-butyl. Examples thereof include a dimethylsilyl group, a methyldi-t-butylsilyl group, a tri-t-butylsilyl group, a phenyldimethylsilyl group, a methyldiphenylsilyl group, and a triphenylsilyl group. As the acyl group, acetyl group, propionyl group, butyryl group, heptanoyl group, hexanoyl group, valeryl group, pivaloyl group, isovaleryl group, lauryl group, myristoyl group, palmitoyl group, stearoyl group, oxalyl group, malonyl group, succinyl group, Glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacoyl group, acryloyl group, propioroyl group, methacryloyl group, crotonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconoyl group, camphoroyl group, benzoyl group, phthaloyl group Group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group, cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group, isonicotinoyl group And the like can be given. Further, those in which some or all of the hydrogen atoms of these acid labile groups are substituted with fluorine atoms can also be used.

[solvent]
Any organic solvent can be used as long as it can dissolve the base resin, acid generator, other additives, and the like as the organic solvent blended in the resist material of the present invention. Examples of such organic solvents include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone, ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, diester Polyhydric alcohols such as propylene glycol or dipropylene glycol monoacetate monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether and derivatives thereof, cyclic ethers such as dioxane, methyl lactate, Ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methoxypropionic acid Esters such as chill and ethyl ethoxypropionate, aromatic solvents such as xylene and toluene, fluorinated solvents such as chlorofluorocarbons, alternative chlorofluorocarbons, perfluoro compounds, and hexafluoroisopropyl alcohol. High-boiling weak solvents for the purpose of improving coatability. A terpene-based petroleum naphtha solvent or a paraffin-based solvent can be used. These may be used alone or in combination of two or more.

  The amount of the organic solvent used is preferably 200 to 1,000 parts by weight, particularly 400 to 800 parts by weight with respect to 100 parts by weight of the base resin.

[Pattern formation method]
The resist material of the present invention is
Applying the resist material on a substrate;
A step of exposing with a high energy ray having a wavelength of 300 nm or less through a photomask after the heat treatment, a step of developing with a developer after heat treatment if necessary,
It can utilize suitably for pattern formation through each process of these.

  As a method of using the resist material of the present invention, a resist pattern forming method of a conventional photoresist technique can be used. That is, first, a resist material is applied to a substrate such as a silicon wafer using a spinner and dried to form a photosensitive layer, and this is irradiated with high energy rays through a desired mask pattern by an exposure apparatus or the like. And heat. Next, this is developed using a developer, for example, an alkaline aqueous solution such as a 0.1 to 10% by weight tetramethylammonium hydroxide aqueous solution. With this forming method, a pattern faithful to the mask pattern can be obtained. Further, additives that are miscible with the resist material as desired, such as additional resins, quenchers, plasticizers, stabilizers, colorants, surfactants, thickeners, leveling agents, antifoaming agents, compatibilizing agents, Various additives such as an adhesive and an antioxidant can be contained.

  The high energy ray having a wavelength of 300 nm or less used in the present invention is not particularly limited, and examples thereof include ultraviolet rays, far ultraviolet rays, extreme ultraviolet rays, electron beams, X-rays, excimer lasers, gamma rays, or synchrotron radiation. In particular, when fine processing is to be performed, it is effective to use an exposure apparatus equipped with a short-wavelength high energy ray source such as an ArF excimer laser, a KrF excimer laser, or EUV. In addition, using a medium that absorbs high energy rays, such as water or a fluorine-based solvent, in part of the optical path, and an immersion exposure system that enables more efficient microfabrication at the numerical aperture and effective wavelength This resist material is suitable for use in this apparatus.

  Among the pattern forming methods described above, an immersion lithography method in which an ArF excimer laser with a wavelength of 193 nm is used and water is inserted between the wafer and the projection lens is one of particularly preferable embodiments.

  EXAMPLES Hereinafter, although an Example, a reference example, and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

Production of sulfonate and onium sulfonate [Example 1-1] Method for producing 2-bromo-2,2-difluoroethyl-cyclohexyl carbamate

  To a 50 mL reactor, 10.0 g of cyclohexyl isocyanate (79.9 mmol / 1.0 equivalent) and 25.1 g of bromo-difluoroethanol (156 mmol / 2.0 equivalent) were added at 40 ° C. Stir for about 18 hours. Then, stirring was stopped and vacuum drying was performed at 60 ° C. to obtain 23.1 g of the target 2-bromo-2,2-difluoroethyl-cyclohexyl carbamate. At this time, the yield was 85%.

[Physical properties of 2-bromo-2,2-difluoroethyl-cyclohexyl carbamate]
¹ H NMR (CDCl ₃ ) δ 4.77 (br, 1H; NH), 4.55 (t, J = 11.7 Hz, 2H, CH ₂ —O), 3.46 (m, 1H, CH) _{, 1.93 (m, 2H, CH} 2), 1.70 (m, 2H, CH 2), 1.59 (m, 1H), 1.33 (m, 2H, CH 2), 1.15 ( m, 3H)
¹⁹ F NMR (CDCl ₃ ) δ-57.0 (t, J = 12 Hz, 2F).

  [Example 1-2] Preparation of sodium cyclohexylcarbamic acid-2,2-difluoroethyl-sulfonate

  After adding 23.0 g (67.5 mmol) of 2-bromo-2,2-difluoroethyl-cyclohexyl carbamate to a 500 mL reactor, the mixture was dissolved in 100 g of acetonitrile. To this solution were added 29.0 g (167 mmol) of sodium dithionite, 17.0 g (202 mmol) of sodium bicarbonate, and 100 g of water, and the mixture was stirred at 60 ° C. for 113 hours. Thereafter, stirring was stopped and the two layers were separated, and then the aqueous layer was extracted four times with 100 g of acetonitrile. The obtained organic layers were combined, concentrated, and acetonitrile was distilled off to obtain 38.3 g (purity 42%) of a pale yellow solid.

  38.2 g (54.2 mmol, purity 42%) of the obtained solid was added to a 200 mL reactor and then dissolved in 100 g of water. To this solution was added 6.75 g (59.5 mmol) of 30% by weight aqueous hydrogen peroxide, and the mixture was stirred at 50 ° C. for 5 hours. After stirring was stopped and the solvent was distilled off, the residue was washed twice with diisopropyl ether and dried to obtain 32.0 g of sodium cyclohexylcarbamic acid-2,2-difluoroethyl-sulfonate. At this time, the purity was 47% and the yield was 71%.

[Physical properties of cyclohexylcarbamic acid-2,2-difluoroethyl-sodium sulfonate]
¹ H NMR (DMSO-d ₆ ) δ 4.46 (t, J = 16.1 Hz, 2H; CH ₂ ), 3.23 (m, 1H; NH), 1.70 (m, 1H), 1 .63 (m, 2H), 1.50 (m, 1H), 1.24-0.90 (m, 6H)
¹⁹ F NMR (DMSO-d ₆ ) δ-113.7 (t, J = 17 Hz, 2F).

  [Example 2] Preparation of triphenylsulfonium cyclohexylcarbamic acid-2,2-difluoroethyl-sulfonate

  A 300 mL reactor was charged with 31.85 g of sodium cyclohexylcarbamic acid-2,2-difluoroethyl-sulfonate (purity 47%, 48.0 mmol), 15.8 g (52.9 mmol) of triphenylsulfonium chloride, 170 g of water. Then, 30 g of chloroform was added, and the mixture was stirred at room temperature for 4 hours. The reaction solution was separated into two layers, and the resulting aqueous layer was extracted with chloroform. The obtained chloroform layers were collectively washed 6 times with water, concentrated, then washed 3 times with diisopropyl ether, dried, and the target triphenylsulfonium cyclohexylcarbamic acid-2,2-difluoroethyl was obtained. -24.5 g of sulfonate were obtained. At this time, the purity was 76% and the yield was 70%.

[Physical Properties of Triphenylsulfonium Cyclohexylcarbamic Acid-2,2-Difluoroethyl-sulfonate Production Method]
¹ H NMR (CDCl ₃ ) δ 7.80-7.58 (m, 15H), 4.83 (m, 1H; NH), 4.68 (t, J = 15.1 Hz, 2H; CH ₂ ), 3.38 (m, 1H), 1.83 (m, 2H), 1.61 (m, 2H), 1.52 (m, 1H), 1.23 (m, 2H), 1.08 (m , 3H)
¹⁹ F NMR (CDCl ₃ ) δ −114.36 (t, J = 14.6 Hz, 2F)
¹³ C NMR (CDCl ₃ ) δ 154.4 (C═O), 134.4, 131.4, 131.0, 124.2, 119.2 (t, J = 278 Hz), 62.2 (t, J = 21 Hz), 49.8, 32.8, 25.1, 24.5.

  [Example 3-1] Method for producing adamantane-1-ylcarbamic acid-2-bromo-2,2-difluoro-ethyl ester

  To a 20 mL reactor, under nitrogen, 4.86 g of 1-adamantyl isocyanate (purity 97%, 26.6 mmol), 10.7 g of bromo-difluoroethanol (66.5 mmol / 2.5 equivalents), THF ( 10 mL of dehydration) was added, and the mixture was stirred at 40 ° C. for an hour. After cooling to room temperature, the insoluble material was filtered off and vacuum dried to obtain 9.15 g of the target adamantane-1-ylcarbamic acid-2-bromo-2,2-difluoro-ethyl ester. At this time, the purity was 74% and the yield was 73%.

[Physical properties of production method of adamantane-1-ylcarbamic acid-2-bromo-2,2-difluoro-ethyl ester]
¹ H NMR (CDCl ₃ ) δ 4.79 (br, 1H; NH), 4.52 (t, J = 11.5 Hz, 2H; CH ₂ ), 2.09 (m, 3H), 1.94 (M, 6H), 1.67 (m, 6H)
¹⁹ F NMR (CDCl ₃ ) δ −56.82 (t, J = 9.8 Hz, 2F)
Example 3-2 Preparation of sodium adamantane-1-ylcarbamic acid-2,2-difluoro-ethyl sulfonate

  In a 100 mL reactor, 9.0 g of adamantane-1-ylcarbamic acid-2-bromo-2,2-difluoro-ethyl ester (purity 73%, 19.4 mmol) and 50 g of acetonitrile were dissolved. To this solution, 13.2 g (75.8 mmol) of sodium dithionite, 7.35 g (87.5 mmol) of sodium hydrogen carbonate, and 50 g of water were added and stirred at 60 ° C. for 145 hours. Thereafter, stirring was stopped and the two layers were separated, and then the aqueous layer was extracted four times with 100 g of acetonitrile. The obtained organic layers were combined, concentrated, and acetonitrile was distilled off to obtain 31.32 g (purity 17%) of a pale yellow solid.

  31.32 g (15.6 mmol, 17% purity) of the obtained solid was added to a 200 mL reactor and then dissolved in 100 g of water. To this solution was added 6.00 g (52.9 mmol) of 30 wt% aqueous hydrogen peroxide, and the mixture was stirred at 50 ° C. for 44 hours. Stirring was stopped and the solvent was distilled off, followed by washing twice with diisopropyl ether and drying to obtain 28.01 g of the target sodium adamantane-1-ylcarbamic acid-2,2-difluoro-ethylsulfonate. It was. At this time, the purity was 15% and the yield was 61%.

[Physical properties of sodium adamantane-1-ylcarbamic acid-2,2-difluoro-ethylsulfonate]
¹ H NMR (DMSO-d ₆ ) δ 4.40 (t, 2H; CH ₂ —O), 2.80 (br, 1H; OH), 1.97 (m, 3H), 1.83 (m, 6H), 1.56 (m, 6H)
¹⁹ F NMR (DMSO-d ₆ ) δ-113.56 (t, J = 14.6 Hz, 2F).

  [Example 4] Preparation of triphenylsulfonium adamantane-1-ylcarbamic acid-2,2-difluoro-ethylsulfonate

  In a 500 mL reactor, 28.0 g of adamantane-1-ylcarbamic acid-2,2-difluoro-ethylsulfonic acid (purity 15%, 11.8 mmol), 4.4 g of triphenylsulfonium chloride (14.5 mmol) 100 g of water and 50 g of chloroform were added, and the mixture was stirred at room temperature for 4 hours. The reaction solution was separated into two layers, and the resulting aqueous layer was extracted with chloroform. The obtained chloroform layers were combined and washed four times with water, concentrated, washed with diisopropyl ether, dried, and the target triphenylsulfonium adamantane-1-ylcarbamic acid-2,2- 6.50 g of difluoro-ethyl sulfonate was obtained. At this time, the purity was 78% and the yield was 92%.

[Physical properties of triphenylsulfonium adamantane-1-ylcarbamic acid-2-bromo-2,2-difluoro-ethylsulfonate]
¹ H NMR (CDCl ₃ ) δ 7.90-7.58 (m, 15H), 4.72 (br, NH), 4.64 (t, J = 14.9 Hz, 2H; CH ₂ ), 1 .99 (m, 3H), 1.83 (m, 6H), 1.58 (m, 6H)
¹⁹ F NMR (CDCl ₃ ) δ −114.27
¹³ C NMR (CDCl ₃ ) δ 152.9 (C═O), 134.2, 131.2, 130.9, 124.2, 119.1 (t, J = Hz), 61.6, 50. 4, 41.3, 35.9, 29.0.

Evaluation of Photoacid Generator Sulphonic acid onium salts prepared as described above [triphenylsulfonium cyclohexylcarbamic acid-2,2-difluoroethylsulfonate (PAG1) and triphenylsulfonium adamantane-1-ylcarbamic acid-2,2- Difluoroethylsulfonate (PAG2)] was evaluated. For comparison, triphenylsulfonium cyclohexyloxycarbonyldifluoromethanesulfonate (PAG3), triphenylsulfonium (adamantan-1-ylmethyl) oxycarbonyldifluoromethanesulfonate (PAG4), triphenylsulfonium 2-cyclohexylcarbonyloxy-1, Evaluation of 1-difluoroethanesulfonate (PAG5), triphenylsulfonium 2- (1′-adamantane) carbonyloxy-1,1-difluoroethanesulfonate (PAG6), triphenylsulfonium nonafluorobutanesulfonate (PAG7) Carried out.

1) Solubility in resist solvent The solubility in propylene glycol monomethyl ether acetate (PGMEA) used as a resist solvent was measured using the PAGs 1 to 6 described above. The measurement results of the solubility (parts by weight of PAG dissolved with respect to 100 parts by weight of PGMEA) are shown in “Table 1”.

  As described above, the sulfonic acid onium salts having a urethane bond according to the present invention (PAG1 and PAG2, Examples 5 and 6) are sulfonic acid onium salts having no urethane bond (PAG3 to PAG6, Comparative Examples 1 and 2). The solubility was more than twice that of Reference Examples 1 and 2).

2) Evaluation of compatibility with resist and resolution of resist Using sulfonic acid onium salt (PAG1 or 2) represented by the above formula as an acid generator, a polymer (resin 1-5) represented by the following formula as a base resin A resist material was prepared by using each of the above, and each composition was filtered through a 0.2 μm membrane filter to prepare resist solutions.

  Next, the entire resist solution was spin-coated on a silicon wafer to obtain a resist film having a thickness of 250 nanometers. After pre-baking at 110 ° C., exposure with 248 nm ultraviolet light was performed through a photomask, and then post-exposure baking was performed at 120 ° C. Then, it developed for 1 minute at 23 degreeC using 2.38 weight% tetramethylammonium hydroxide aqueous solution. Table 2 shows the composition and evaluation results of each resist.

  For comparison, the sulfonic acid onium salts represented by the above formulas (PAG3, PAG4, and PAG7) are evaluated for the compatibility of the PAG and the evaluation of the resolution of the resist when the resist is formed under the same conditions as in the examples. .

  From the results of Tables 2 and 3, the sulfonic acid onium salts (PAG1 and PAG2) of the present invention exhibit higher compatibility with the resist than the conventional products, and the sulfonic acid onium salts (PAG1 and PAG2) of the present invention are used. It was confirmed that the resist material obtained showed high resolution.

Claims (21)

A fluorine-containing sulfonic acid onium salt represented by the following general formula (3).
(In the formula, n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 1 to 20 carbon atoms. A linear, branched or cyclic alkenyl group, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms is shown.
Q ⁺ represents a sulfonium cation represented by the following general formula (a) or the following general formula (b), or an iodonium cation represented by the following general formula (c).
In the general formula (a), R ¹ , R ² and R ³ are each independently a substituted or unsubstituted C 1-10 linear or branched alkyl group, alkenyl group or oxoalkyl group, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, aralkyl or aryloxoalkyl group, or any two of ^R 1, ^{R 2} and ^{R 3} are bonded to each other 1,4 A butylene group or a 3-oxa-1,5-pentylene group may be formed, and a ring may be formed together with the sulfur atom in the formula.
In the general formula (b), R ⁴ represents a substituted or unsubstituted linear, branched or cyclic alkyl group or alkenyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 14 carbon atoms. Indicates a group. r represents an integer of 1 to 5, and q represents 0 (zero) or 1.
In the general formula (c), R ⁴ represents a substituted or unsubstituted linear, branched or cyclic alkyl group or alkenyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 14 carbon atoms. Indicates a group. r represents an integer of 1 to 5, and q represents 0 (zero) or 1. ) A fluorine-containing N-sulfonyloxyimide compound represented by the following general formula (4).
(In the general formula (4), n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted carbon. A linear, branched or cyclic alkenyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms, Z is a single bond or a double bond. A bond, a methylene group or an oxygen atom, T and Y independently represent a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or T and Y are bonded together An aliphatic cyclic structure, an aromatic ring structure or a heterocyclic structure may be formed including carbon atoms.) A fluorine-containing oxime sulfonate compound represented by the following general formula (5).
(In the general formula (5), n each independently represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted, An unsubstituted linear, branched or cyclic alkenyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms, where m is 0. Or, when m is 0, p represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 15 carbon atoms, and m is 1 In the above, p represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 15 carbon atoms, A represents a cyano group, a trifluoromethyl group, a peroxy group. Fluoroethyl group, perfluoro A propyl group, a 5H-perfluoropentyl group, a 6H-perfluorohexyl group, a nitro group or a methyl group. When m is 1, carbon atoms are bonded together with carbon atoms to which they are bonded to each other. (Formula 6 ring may be formed.) A fluorine-containing sulfonate represented by the following general formula (1).
(In the formula, n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 1 to 20 carbon atoms. A linear, branched or cyclic alkenyl group, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms, M ⁺ represents a lithium ion, a sodium ion, a potassium ion, (Ammonium ion or tetramethylammonium ion is shown.) Responds to high energy rays of ultraviolet rays, far ultraviolet rays, extreme ultraviolet rays, electron beams, X-rays, excimer lasers, γ rays, or synchrotron radiation, and generates fluorine-containing sulfonic acids represented by the following general formula (2). It is selected from the fluorine-containing sulfonic acid onium salt shown in claim 1, the fluorine-containing N-sulfonyloxyimide compound shown in claim 2, and the fluorine-containing oxime sulfonate compound shown in claim 3. A photoacid generator for chemically amplified resist materials.
(In the formula, n represents an integer of 1 to 10. R represents a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 1 to 20 carbon atoms. A linear, branched or cyclic alkenyl group, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms or a heteroaryl group having 4 to 15 carbon atoms.) Ultraviolet, far ultraviolet, extreme ultraviolet, electron beam, X-ray, excimer laser, gamma rays, or sensitive to high energy radiation of the synchrotron radiation, the fluorinated sulfonic acid onium salt according to claim 1, in claim 2 A photoacid generator for a chemically amplified resist material, comprising at least one of the fluorine-containing N-sulfonyloxyimide compound according to claim 3 or the fluorine-containing oxime sulfonate compound according to claim 3 . The photoacid generator according to claim 6 is irradiated with high energy rays such as ultraviolet rays, far ultraviolet rays, extreme ultraviolet rays, electron beams, X-rays, excimer lasers, γ rays, or synchrotron radiation. A method for producing a fluorine-containing sulfonic acid represented by the general formula (2) described in 5 . In a resist material comprising a base resin, a photoacid generator, and a solvent, the photoacid generator generates the fluorinated sulfonic acid represented by the general formula (2) according to claim 5. A resist material characterized by being an agent. A resist material comprising a base resin, a photoacid generator and a solvent, wherein the photoacid generator is the photoacid generator according to claim 6 . Base resin is olefin, fluorine-containing olefin, acrylic ester, methacrylic ester, fluorine-containing acrylic ester, fluorine-containing methacrylate ester, norbornene compound, fluorine-containing norbornene compound, styrene compound, fluorine-containing styrene compound, vinyl ether, And a polymer obtained by polymerizing one monomer selected from the group consisting of fluorine-containing vinyl ethers, or a polymer copolymer obtained by copolymerizing two or more of the above monomers. The resist material according to claim 8 or 9 . The resist material according to claim 8 or 9 , wherein the base resin is a polymer compound containing a repeating unit represented by the following general formula (6).
(In the general formula (6), R ⁵ represents a hydrogen atom, a halogen atom, an alkyl group or a fluorine-containing alkyl group, and R ⁶ represents a linear or branched alkyl group or an alkyl group having a cyclic structure. , An aromatic ring, or a composite substituent thereof, part of which may be fluorinated, R ⁷ represents a hydrogen atom, a hydrocarbon group that may contain a branch, a fluorine-containing alkyl group, an aromatic group, (A ring having an alicyclic ring, which may contain a bond of oxygen and carbonyl, and s represents an integer of 1 to 2) The resist material according to claim 8 or 9, wherein the base resin is a polymer compound containing a repeating unit represented by the following general formula (7).
(In the general formula (7), R ⁵ represents a hydrogen atom, a halogen atom, a hydrocarbon group, or a fluorine-containing alkyl group, and any one of R ⁸ , R ⁹ , and R ¹⁰ is CF ₃ C (CF ₃ ) (OH) CH ₂ - group wherein the remaining two are hydrogen). The resist material according to claim 8 or 9, wherein the base resin is a polymer compound containing a repeating unit represented by the following general formula (8).
(In the general formula (8), R ⁵ represents a hydrogen atom, a halogen atom, a hydrocarbon group, or a fluorine-containing alkyl group, and R ¹¹ represents a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, or perfluoroethyl group.) The resist material according to claim 8 or 9, wherein the base resin is a polymer compound containing a repeating unit represented by the following general formula (9).
(In the general formula (9), R ⁵ represents a hydrogen atom, a halogen atom, a hydrocarbon group, or a fluorine-containing alkyl group, R ¹² represents a methyl group or a trifluoromethyl group, and R ¹³ represents a hydrogen atom or a carbon number. A group containing 1 to 25 linear hydrocarbon group, a branched or cyclic hydrocarbon group having 3 to 25 carbon atoms, or an aromatic hydrocarbon group having 6 to 26 carbon atoms, part of which is fluorine atom, an oxygen atom, may also include a carbonyl bond .u represents any integer of 0 to 2, t, v represents any integer of 1 to 8, satisfying the ^{v ≦ t + 2 .R 12 ~R} 13 is In the case of a plurality, R ^{12 to} R ¹³ may be the same or different.) The resist material according to claim 8 or 9 , wherein the base resin contains a repeating unit represented by the following general formula (10).
(In the general formula (10), X represents any of —CH ₂ —, —O—, and —S—. W represents an integer of 2 to 6.) The resist material according to claim 8 or 9 , wherein the base resin contains a repeating unit represented by the following general formula (11).
(In the general formula (11), R ⁵ represents a hydrogen atom, a halogen atom, an alkyl group or a fluorine-containing alkyl group, R ¹⁵ represents a fluorine atom or a fluorine-containing alkyl group, and J represents a divalent linking group. ¹⁴ is an acid labile protecting group represented by any one of the following general formulas (d) to (h).
In the general formula (d), R ¹⁶ is an alkyl group which may have a substituent having 1 to 4 carbon atoms, and an alicyclic hydrocarbon group which may have a substituent having 3 to 30 carbon atoms. Or the aryl group which may have a C6-C14 substituent may be represented.
In Formula ^{(e), R 16} has the same meaning as ^{R 16} in the formula (d). R ¹⁷ is a hydrogen atom, an alkyl group which may have a substituent having 1 to 4 carbon atoms, an alicyclic hydrocarbon group which may have a substituent having 3 to 30 carbon atoms, An alkoxy group optionally having 6 substituents, an alkenyl group optionally having 2 to 4 carbon atoms, and an aryl group optionally having a substituent having 6 to 14 carbon atoms Alternatively, it represents an aralkyl group which may have a substituent having 7 to 20 carbon atoms.
In the said general formula (f), R <^18> , R <^19> and R <^20> may be same or different, respectively, The alkyl group which may have a C1-C4 substituent, C3-C30 An alicyclic hydrocarbon group that may have a substituent, an alkenyl group that may have a substituent having 2 to 4 carbon atoms, or a substituent that has 6 to 14 carbon atoms It represents a good aryl group or an aralkyl group which may have a substituent having 7 to 20 carbon atoms. Two groups out of R ^{18 to} R ²⁰ may be bonded to form a ring.
In the general formula ^(g), R ^{18, R 19} and ^{R 20} have the same meanings as ^{R 18, R 19} and ^{R 20} in the general formula (f).
In formula ^{(h), R 16} has the same meaning as ^{R 16} in the formula (d). ) The chemically amplified positive resist material according to any one of claims 8 to 16 , wherein the base resin is insoluble or hardly soluble in the developer and becomes soluble in the developer by an acid. A step of applying the resist material according to any one of claims 8 to 17 on a substrate, a step of exposing with a high energy ray having a wavelength of 300 nm or less through a photomask after the heat treatment, and a heat treatment as necessary. And a step of developing using a developing solution. The immersion lithography method uses an ArF excimer laser with a wavelength of 193 nm and inserts water or a liquid other than water having a refractive index higher than the refractive index in the air between the substrate coated with the resist material and the projection lens. The pattern forming method according to claim 18, wherein: Triphenylsulfonium cyclohexylcarbamic acid-2,2-difluoroethyl-sulfonate represented by the following formula:
Triphenylsulfonium adamantane-1-ylcarbamic acid-2-bromo-2,2-difluoro-ethyl sulfonate represented by the following formula: