JP5828715B2 - Sulfonium salt, photoacid generator, curable composition, and resist composition - Google Patents

Description

  The present invention relates firstly to a sulfonium salt, and secondly, when a cationically polymerizable compound is cured by applying an active energy ray such as light, electron beam or X-ray to a photoacid generator. The present invention relates to a photoacid generator containing a suitable specific sulfonium salt. Thirdly, the present invention relates to a curable composition containing the photoacid generator and a cured product obtained by curing the curable composition. Fourthly, the present invention relates to a chemically amplified positive photoresist composition containing the photoacid generator and a method for producing a resist pattern using the same. Fifthly, the present invention relates to a chemical amplification type chemically amplified negative photoresist composition containing the photoacid generator and a cured product obtained by curing the composition.

The photoacid generator is a general term for compounds that decompose to generate an acid upon irradiation with active energy rays such as light, electron beam, or X-ray, and an acid generated by irradiation with active energy rays is used as an active species. It is used for various reactions such as polymerization, crosslinking, and deprotection.
Specific examples include polymerization of a cationic polymerizable compound, a crosslinking reaction in the presence of a phenol resin and a crosslinking agent, and an acid-catalyzed deprotection reaction of a polymer in which a protecting group is introduced into an alkali-soluble resin.
In recent years, photolithography technology using a photoresist has been used to manufacture electronic components and semiconductor elements, and in particular, various precision components such as semiconductor packages have a wavelength of 365 nm as an active energy ray. i-line is widely used. This is because an intermediate-pressure / high-pressure mercury lamp that is inexpensive and has good emission intensity can be used as an irradiation light source.
In addition, medium pressure / high pressure mercury lamps are most commonly used in fields such as paint, adhesion, and coating other than photolithography, and recently, LED lamps having an emission wavelength in the i-line region (360 nm to 390 nm) have become popular. It can also be mentioned. Therefore, the need for a photoacid generator exhibiting high sensitivity to i-line is expected to increase further in the future.

  However, among existing photoacid generators, triarylsulfonium salts (Patent Document 1), phenacylsulfonium salts having a naphthalene skeleton (Patent Document 2) and dialkylbenzylsulfonium salts (Patent Document 3) are sensitive to i-line. Because of its low nature, it is necessary to use a sensitizer together to increase sensitivity. In addition, the sulfonium salt introduced with a thioxanthone skeleton (Patent Document 4) has a problem that the absorption rate is too large with respect to i-line, and therefore, light curing does not pass to the deep part at the time of thick film curing, resulting in a problem of poor curing.

In recent years, with the further miniaturization of electronic devices, high-density mounting of semiconductor packages has progressed. Multi-pin thin-film mounting and downsizing of packages, mounting based on two-dimensional and three-dimensional mounting techniques using a flip chip method The density is improved. As a material used for such high-precision photofabrication, there is a positive photosensitive resin composition (Patent Document 5, Non-Patent Documents 1 and 2) using an oxime sulfonate compound as an acid generator. This is because the acid is generated from the photoacid generator by irradiation (exposure), and the diffusion of the acid and the acid catalyzed reaction are promoted by the heat treatment after the exposure, thereby improving the solubility of the base resin in the resin composition in the alkali. The base resin that is insoluble in alkali before exposure is solubilized in alkali and is called a positive photoresist. However, since this resist composition contains oxime sulfonate, the storage stability is poor, and the storage temperature control of the resist composition is complicated, and there are practical problems.

Furthermore, a photosensitive resin composition using an alkali-soluble resin having a phenolic hydroxyl group and a triazine photoacid generator has been proposed for a surface protective film, an interlayer insulating film, etc. used in a semiconductor element of an electronic device (patent) References 6 and 7). This is because an acid is generated from the photoacid generator upon exposure, and the reaction between the crosslinking agent and the alkali-soluble resin is promoted to become insoluble in the developer. This is called a negative photoresist. This triazine-based photoacid generator has a problem of contaminating equipment because the generated acid is hydrochloric acid or odorous acid and is likely to volatilize.

Japanese Patent Laid-Open No. 50-151997 JP-A-9-118663 JP-A-2-178303 JP-A-8-165290 JP 2000-66385 A JP 2008-77057 A WO2008-117619

M.J.O'Brien, J.V.Crivello, SPIE Vol. 920, Advances in Resist Technology and Processing, p42 (1988). H.ITO, SPIE Vol.920, Advances in Resist Technology and Processing, p33, (1988).

In the above background, the first object of the present invention is to provide a new sulfonium salt having high photosensitivity to i-line.
The second object of the present invention is to store in a blend with a cationically polymerizable compound such as an epoxy compound having high photosensitivity to i-line and high compatibility with a cationically polymerizable compound such as an epoxy compound. It is to provide a new photoacid generator comprising a sulfonium salt having excellent stability.
The third object of the present invention is to provide an energy ray curable composition and a cured product using the photoacid generator.
A fourth object of the present invention is to provide a chemically amplified positive photoresist composition using the photoacid generator and a method for producing the same.
A fifth object of the present invention is to provide a chemically amplified positive photoresist composition using the photoacid generator and a cured product thereof.

The inventor has synthesized a sulfonium salt represented by the following formula (1) and found that it is suitable for each of the above purposes.
That is, the present invention is a sulfonium salt represented by the following general formula (1).

[R in the formula (1) represents an alkyl group, and R ^{1 to} R ³ are each independently an alkyl group, a hydroxyl group, an alkoxy group, an aryl group, an aryloxy group, a hydroxy (poly) alkyleneoxy group, a cyano group. Represents a group, a nitro group or a halogen atom. m ^{1 to} m ³ each represent the number of R ^{1 to} R ³ , m ¹ represents an integer of 0 to 4, m ² and m ³ represent an integer of 0 to 5, and X ⁻ represents SbF ₆ ⁻ or PF ₆ ^−. , BF ₄ ⁻ , ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ B ⁻ , (C ₆ F ₅ ) ₄ Ga ⁻ , ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ Ga ⁻ , trifluoromethanesulfonic acid anion , Nonafluorobutanesulfonate anion, methanesulfonate anion, butanesulfonate anion, camphorsulfonate anion, benzenesulfonate anion, p-toluenesulfonate anion, (CF ₃ SO ₂ ) ₃ C ⁻ , and (CF ₃ SO It represents a monovalent polyatomic anion selected from the group consisting of anions represented by ^- _{2) 2} N. ]

The present invention also provides a photoacid generator containing the sulfonium salt.

  Moreover, this invention is an energy beam curable composition characterized by containing the said photo-acid generator and a cationically polymerizable compound.

  Furthermore, the present invention is a cured product obtained by curing the energy beam curable composition.

  Furthermore, the present invention provides a chemically amplified positive photoresist composition comprising the photoacid generator and a component (B) which is a resin whose solubility in alkali is increased by the action of an acid. is there.

  Furthermore, the present invention provides a laminating step of laminating a photoresist layer having a film thickness of 5 to 150 μm comprising any one of the above chemically amplified positive photoresist compositions to obtain a photoresist laminate, A method for producing a resist pattern, comprising: an exposure step of selectively irradiating light or radiation with a part; and a development step of developing a photoresist laminate to obtain a resist pattern after the exposure step.

  The present invention further includes a chemically amplified negative photo, comprising the photoacid generator, a component (F) which is an alkali-soluble resin having a phenolic hydroxyl group, and a crosslinking agent component (G). It is a resist composition.

  Furthermore, the present invention is a cured product obtained by curing any one of the above chemically amplified negative photoresist compositions.

The sulfonium salt of the present invention has excellent photosensitivity to active energy rays such as visible light, ultraviolet rays, electron beams and X-rays, has high compatibility with cationically polymerizable compounds such as epoxy compounds, and cationic polymerization of epoxy compounds and the like. Storage stability is excellent in a blend with a functional compound.
The photoacid generator of the present invention has excellent curability due to the action of ultraviolet light, particularly i rays, when used for curing a cationically polymerizable compound, and cures a cationically polymerizable compound without using a sensitizer. Can be made. The photoacid generator of the present invention is also excellent in thick film curability.
Since the energy beam curable composition of the present invention contains the above-mentioned photoacid generator, it can be cured with ultraviolet light. Moreover, since the energy beam curable composition of this invention has high storage stability and does not need to use a sensitizer, it is excellent in cost and workability | operativity.
Since the cured product of the present invention can be obtained without using a sensitizer, there is no problem of coloring or deterioration due to the remaining sensitizer.
Since the chemical amplification type positive photoresist composition and the chemical amplification type negative photoresist composition of the present invention contain the above-mentioned photoacid generator, they are resists that are highly sensitive to i-line (compared to conventional ones). Pattern formation is possible with a low exposure amount). Furthermore, the chemically amplified positive photoresist composition and the chemically amplified negative photoresist composition of the present invention have high storage stability and good resist pattern shape.

  Hereinafter, embodiments of the present invention will be described in detail.

The sulfonium salt of the present invention is represented by the following general formula (1).

  In the formula (1), in R, as the alkyl group, a linear alkyl group having 1 to 18 carbon atoms (methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl and the like), a branched alkyl group having 1 to 18 carbon atoms (isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, Isohexyl and isooctadecyl), and cycloalkyl groups having 3 to 18 carbon atoms (cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 4-decylcyclohexyl, etc.) and the like.

  In Formula (1), among R, examples of the aryl group include aryl groups having 6 to 12 carbon atoms (such as phenyl, tolyl, dimethylphenyl, naphthyl, and biphenylyl).

In formula (1), among R ^{1 to} R ³ , the alkyl group is a linear alkyl group having 1 to 18 carbon atoms (methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, etc.), a branched alkyl group having 1 to 18 carbon atoms (isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl and isooctadecyl), and cycloalkyl groups having 3 to 18 carbon atoms (such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and 4-decylcyclohexyl).

In the formula (1), among R ^{1 to} R ³ , the alkoxy group is a linear or branched alkoxy group having 1 to 18 carbon atoms (methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy Tert-butoxy, hexyloxy, decyloxy, dodecyloxy, octadecyloxy and the like).

In Formula (1), among R ^{1 to} R ³ , examples of the aryl group include aryl groups having 6 to 10 carbon atoms (such as phenyl, tolyl, dimethylphenyl, naphthyl, and biphenylyl).

In formula (1), among R ^{1 to} R ³ , examples of the aryloxy group include aryloxy groups having 6 to 10 carbon atoms (such as phenoxy and naphthyloxy).

In Formula (1), among R ^{1 to} R ³ , examples of the hydroxy (poly) alkyleneoxy group include a hydroxy (poly) alkyleneoxy group represented by Formula (2).

HO (-AO) q- (2)
[AO represents an ethyleneoxy group and / or a propyleneoxy group, and q represents an integer of 1 to 5. ]

In Formula (1), among R ^{1 to} R ³ , examples of the halogen atom group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In the formula (1), R ^{1 to} R ³ are independent of each other, and therefore may be the same as or different from each other.

  R is preferably an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms, more preferably a methyl group, a butyl group, a phenyl group, a naphthyl group, or a biphenylyl group. In view of the above, a methyl group and a phenyl group are particularly preferable.

Among R ^{1 to} R ³ , an alkyl group, an alkoxy group, an aryloxy group, and a halogen atom are preferable, and a methyl group, a methoxy group, a phenoxy group, and a halogen atom are particularly preferable.

In Formula (1), m ^{1 to} m ³ each represent the number of R ^{1 to} R ³ , m ¹ is an integer of 0 to 4, preferably 0 to 2, more preferably 0 or 1, most preferably Is 0. M ² or m ³ is an integer of 0 to 5, preferably 0 to 2, more preferably 0 or 1, and most preferably 0. When m ^{1 to} m ³ are in these preferable ranges, the photosensitivity and solubility of the sulfonium salt are improved.

Of the sulfoniums represented by formula (1), preferred specific examples are shown below.

  Of the sulfoniums represented by the formula (1), those having the following structures are particularly preferred from the viewpoint of photosensitivity.

In Formula (1), X ⁻ is an anion corresponding to an acid (HX) generated by irradiating a sulfonium salt with an active energy ray (visible light, ultraviolet ray, electron beam, X-ray, etc.). X ⁻ is not limited except that it is a monovalent polyatomic anion, but MY _a ⁻ , (Rf) _b PF _6-b ⁻ , R ⁸ _c BY _4-c ⁻ , R ⁸ _c GaY _{4 ^{-c -, R 9 SO 3 -}} , (R 9 SO 2) 3 C - or _{^{(R 9 SO 2) 2 N}} - anion represented by are preferred.

M represents a phosphorus atom, a boron atom or an antimony atom.
Y represents a halogen atom (a fluorine atom is preferred).

Rf represents an alkyl group (preferably an alkyl group having 1 to 8 carbon atoms) in which 80 mol% or more of hydrogen atoms are substituted with fluorine atoms. Examples of the alkyl group to be converted into Rf by fluorine substitution include linear alkyl groups (such as methyl, ethyl, propyl, butyl, pentyl and octyl), branched chain alkyl groups (such as isopropyl, isobutyl, sec-butyl and tert-butyl) and And cycloalkyl groups (cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.) and the like. The ratio of hydrogen atoms of these alkyl groups substituted by fluorine atoms in Rf is preferably 80 mol% or more, more preferably 90, based on the number of moles of hydrogen atoms that the original alkyl group had. % Or more, particularly preferably 100%. When the substitution ratio by fluorine atoms is within these preferable ranges, the photosensitivity of the sulfonium salt is further improved. As particularly preferred Rf, CF _3- , CF ₃ CF _2- , (CF ₃ ) ₂ CF-, CF ₃ CF ₂ CF _2- , CF ₃ CF ₂ CF ₂ CF _2- , (CF ₃ ) ₂ CFCF _2- , CF ₃ CF ₂ (CF ₃ ) CF— and (CF ₃ ) ₃ C—. The b Rf's are independent of each other, and therefore may be the same as or different from each other.

  P represents a phosphorus atom, and F represents a fluorine atom.

R ⁸ represents a phenyl group in which a part of hydrogen atoms is substituted with at least one element or electron withdrawing group. Examples of such one element include a halogen atom, and include a fluorine atom, a chlorine atom and a bromine atom. Examples of the electron withdrawing group include a trifluoromethyl group, a nitro group, and a cyano group. Of these, a phenyl group in which one hydrogen atom is substituted with a fluorine atom or a trifluoromethyl group is preferable. c number of R ⁸ is independently from each other, therefore, it may be the same or different from each other.

  B represents a boron atom, and Ga represents a gallium atom.

R ⁹ represents an alkyl group having 1 to 20 carbon atoms, a perfluoroalkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and the alkyl group and the perfluoroalkyl group are linear or branched. Alternatively, it may be cyclic, and the aryl group may be unsubstituted or may have a substituent.

S represents a sulfur atom, O represents an oxygen atom, C represents a carbon atom, and N represents a nitrogen atom.
a represents an integer of 4 to 6.
b is preferably an integer of 1 to 5, more preferably 2 to 4, and particularly preferably 2 or 3.
c is preferably an integer of 1 to 4, more preferably 4.

Examples of the anion represented by MY _a ⁻ include anions represented by SbF ₆ ⁻ , PF ₆ ⁻ and BF ₄ ⁻ .

Examples of the anion represented by (Rf) _b PF _6-b ^— include (CF ₃ CF ₂ ) ₂ PF ₄ ⁻ , (CF ₃ CF ₂ ) ₃ PF ₃ ⁻ , ((CF ₃ ) ₂ CF) ₂ PF _4. ⁻ , ((CF ₃ ) ₂ CF) ₃ PF ₃ ⁻ , (CF ₃ CF ₂ CF ₂ ) ₂ PF ₄ ⁻ , (CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ⁻ , ((CF ₃ ) ₂ CFCF ₂ ) ₂ PF ₄ ⁻ , ((CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ⁻ , (CF ₃ CF ₂ CF ₂ CF ₂ ) ₂ PF ₄ ⁻ and (CF ₃ CF ₂ CF ₂ CF ₂ ) ₃ PF ₃ ⁻ Anions and the like. Among these, (CF ₃ CF ₂ ) ₃ PF ₃ ⁻ , (CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ⁻ , ((CF ₃ ) ₂ CF) ₃ PF ₃ ⁻ , ((CF ₃ ) ₂ CF) ₂ Anions represented by PF ₄ ⁻ , ((CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ^— and ((CF ₃ ) ₂ CFCF ₂ ) ₂ PF ₄ ^— are preferred.

The anion represented ^{_{by, (C 6 F 5) 4}} B - - R 8 c BY 4-c, ((CF 3) 2 C 6 H 3) 4 B -, (CF 3 C 6 H 4) 4 Anions represented by B ⁻ , (C ₆ F ₅ ) ₂ BF ₂ ⁻ , C ₆ F ₅ BF ₃ ⁻ and (C ₆ H ₃ F ₂ ) ₄ B ⁻ are included. Of _{these, (C 6 F 5) 4} B - , and _{((CF 3) 2 C 6} H 3) 4 B - anion represented by are preferred.

The anion represented ^{_{by, (C 6 F 5) 4}} Ga - - R 8 c GaY 4-c, ((CF 3) 2 C 6 H 3) 4 Ga -, (CF 3 C 6 H 4) 4 _{^{Ga -, (C 6 F 5}} ) 2 GaF 2 -, C 6 F 5 GaF 3 - and _{(C 6 H 3 F 2)} 4 Ga - anion represented by like. Among these, anions represented by (C ₆ F ₅ ) ₄ Ga ⁻ and ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ Ga ⁻ are preferable.

Examples of the anion represented by R ⁹ SO ₃ ^— include trifluoromethanesulfonic acid anion, pentafluoroethanesulfonic acid anion, heptafluoropropanesulfonic acid anion, nonafluorobutanesulfonic acid anion, pentafluorophenylsulfonic acid anion, p-toluene. Examples include a sulfonate anion, a benzenesulfonate anion, a camphorsulfonate anion, a methanesulfonate anion, an ethanesulfonate anion, a propanesulfonate anion, and a butanesulfonate anion. Of these, trifluoromethanesulfonate anion, nonafluorobutanesulfonate anion, methanesulfonate anion, butanesulfonate anion, camphorsulfonate anion, benzenesulfonate anion and p-toluenesulfonate anion are preferred.

Examples of the anion represented by (R ⁹ SO ₂ ) ₃ C ⁻ include (CF ₃ SO ₂ ) ₃ C ⁻ , (C ₂ F ₅ SO ₂ ) ₃ C ⁻ , and (C ₃ F ₇ SO ₂ ) ₃ C ^−. and _{(C 4 F 9 SO 2)} 3 C - anion such as represented and the like.

The anion represented ^{_{by, (CF 3 SO 2) 2}} N - - (R 9 SO 2) 2 N, (C 2 F 5 SO 2) 2 N -, (C 3 F 7 SO 2) 2 N - and _{(C 4 F 9 SO 2)} 2 N - anion, and the like represented.

As monovalent polyatomic anions, MY _a ⁻ , (Rf) _b PF _6-b ⁻ , R ⁸ _c BY _4-c ⁻ , R ⁸ _c GaY _4-c ⁻ , R ⁹ SO ₃ ⁻ , (R ⁹ SO _{2) 3} C ^- or ^{_{(R 9 SO 2) 2 N}} - besides the anion represented by the perhalogenated acid ion _{^(ClO 4} ^-, BrO 4 -, etc.), halogenated sulfonic acid ion ^_(FSO 3 -, ClSO ₃ ^- and the like), sulfate ion ^{_{(CH 3 SO 4 -, CF}} 3 SO 4 -, HSO 4 - , etc.), carbonate ions ^_(HCO 3 -, _CH 3 CO ₃ ^-, etc.), aluminate ions (AlCl ₄ ^-, AlF ₄ ^-, etc.), hexafluoro bismuthate ions (BiF ₆ ^-), carboxylate ion ^{_{(CH 3 COO -, CF 3}} COO -, C 6 H 5 COO -, CH 3 C 6 H 4 COO -, C 6 F 5 CO ^{_{-, CF 3 C 6 H 4}} COO - , etc.), an aryl boronic acid ions ^{_{(B (C 6 H 5)}} 4 -, CH 3 CH 2 CH 2 CH 2 B (C 6 H 5) 3 - , etc.), thiocyanate ion (SCN ⁻ ), nitrate ion (NO ₃ ⁻ ) and the like can be used.

These X ^{- _{of, MY a -, (Rf)}} b PF 6-b -, R 8 c BY 4-c -, R 8 c GaY 4-c -, R 9 SO 3 -, (R 9 SO 2 ) ₃ C ^- or _{^{(R 9 SO 2) 2 N}} - anion is preferably represented _{^{by, SbF 6 -, PF 6 -}} , (CF 3 CF 2) 3 PF 3 -, (C 6 F 5) 4 B -, ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ B ⁻ , (C ₆ F ₅ ) ₄ Ga ⁻ , ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ Ga ⁻ , trifluoromethanesulfonic acid anion, nonafluorobutanesulfone anion, methanesulfonic acid anion, butanoic acid anion, camphorsulfonic acid anion, benzenesulfonic acid anion, p- toluenesulfonate _{anion, (CF 3 SO 2) 3} C - and _(CF 3 S More preferably in that the better the resolution of the resist, the pattern _{shape, (CF 3 CF 2) 3} PF 3 - - 2) 2 N, nonafluorobutanesulfonic acid _{anion, (C 6 F 5) 4} B - , and ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ B ⁻ and (CF ₃ SO ₂ ) ₃ C ⁻ are particularly preferable because they are more compatible with the resist composition.

Among the sulfonium salts represented by the formula (1), preferred examples include [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium tris (pentafluoroethyl) trifluorophosphate, [4- (4-acetyl) phenylthio ] Phenyl diphenylsulfonium tetrakis (pentafluorophenyl) borate, [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium tris (trifluoromethanesulfonyl) methide, [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium hexafluoroantimonate , [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium hexafluorophosphate, [4- (4-acetyl) phenylthio] phenyl dipheny Rusulfonium trifluoromethanesulfonate, [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium nonafluorobutanesulfonate, [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium methanesulfonate, [4- (4-acetyl) phenylthio] Phenyl diphenylsulfonium butanesulfonate, [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium camphorsulfonate, [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium p-toluenesulfonate, and [4- (4-benzoyl) phenylthio ] Phenyl diphenylsulfonium tris (pentafluoroethyl) trifluorophosphate, [4- (4-benzoyl) Phenylthio] phenyl diphenylsulfonium tetrakis (pentafluorophenyl) borate, [4- (4-benzoyl) phenylthio] phenyl diphenylsulfonium tris (trifluoromethanesulfonyl) methide, [4- (4-benzoyl) phenylthio] phenyl diphenylsulfonium hexafluoroantimo [4- (4-benzoyl) phenylthio] phenyl diphenylsulfonium hexafluorophosphate, [4- (4-benzoyl) phenylthio] phenyl diphenylsulfonium trifluoromethanesulfonate, [4- (4-benzoyl) phenylthio] phenyl diphenylsulfonium nona Fluorobutanesulfonate, [4- (4-benzoyl) phenylthio] phenyl diph Nylsulfonium methanesulfonate, [4- (4-benzoyl) phenylthio] phenyl diphenylsulfonium butanesulfonate, [4- (4-benzoyl) phenylthio] phenyl diphenylsulfonium camphorsulfonate, [4- (4-benzoyl) phenylthio] phenyl diphenylsulfonium p-toluenesulfonate is mentioned.

  The sulfonium salt can be produced by the production method described below.

In the above reaction formula, R, R ^{1 to} R ³ , X ⁻ , and m ^{1 to} m ³ are the same as defined in Formula (1).
Al represents aluminum, Cl represents chlorine, and X ′ represents a monovalent polyatomic anion. Examples of X ′ include a methanesulfonate anion, a perfluoroalkylsulfonate anion, and a hydrogen sulfate anion.
The monovalent polyatomic anion (X ′ ⁻ ) can be exchanged with the other anion (X ⁻ ) of the present invention by, for example, a metathesis reaction as described above.
MX represents an alkali metal (lithium, sodium, potassium, etc.) cation and another anion of the present invention (for example, MY _a ⁻ , (Rf) _b PF _6-b ⁻ , R ⁸ _c BY _4-c ⁻ , R ⁸ _{c ^{GaY 4-c -, R 9}} SO 3 - represents a salt of an anion represented by _{^{like) -, (R 9 SO 2}} ) 3 C -, R 9 SO 2) 2 N.

  In the above reaction formula, the first-stage reaction may be carried out in the absence of a solvent, and if necessary, an organic solvent (general solvents used in Friedel-Crafts reaction such as chloroform, dichloromethane, chlorobenzene, nitromethane, etc.) You may go inside. The reaction temperature is about −20 to 150 ° C. depending on the boiling point of the solvent used. The reaction time is about 1 to several tens of hours.

  The reaction in the second stage may be performed subsequent to the reaction in the first stage, or may be performed after the precursor (2) is isolated (purified as necessary). The precursor (2) and an aqueous solution of a salt (MX) of an alkali metal cation and a monovalent polyatomic anion were mixed and stirred to perform a metathesis reaction, and the precipitated solid was filtered or separated. The sulfonium salt of the present invention is obtained as a solid or viscous liquid by extracting the oily substance with an organic solvent and removing the organic solvent. The obtained solid or viscous liquid can be washed with a suitable organic solvent, if necessary, or purified by recrystallization or column chromatography.

The chemical structure of the sulfonium salt of the present invention can be determined by a general analytical method (for example, ¹ H-, ¹¹ B-, ¹³ C-, ¹⁹ F-, ³¹ P-nuclear magnetic resonance spectrum, infrared absorption spectrum and / or element). Analysis).

  The photoacid generator of the present invention contains a sulfonium salt represented by the formula (1), but contains other conventionally known photoacid generators in addition to the photoacid generator represented by the formula (1). You may use it.

  When other photoacid generator is contained, the content (mol%) of the other photoacid generator is 0 with respect to the total number of moles of the photoacid generator represented by the formula (1) of the present invention. 0.1 to 100 is preferable, and 0.5 to 50 is more preferable.

  Other photoacid generators include conventionally known compounds such as onium salts (sulfonium, iodonium, selenium, ammonium, phosphonium, etc.) and salts of transition metal complex ions with anions.

  When the photoacid generator represented by formula (1) is used, it does not hinder polymerization, crosslinking, deprotection reaction, etc. in advance in order to facilitate dissolution in a cationically polymerizable compound or a chemically amplified resist composition. It may be dissolved in a solvent.

  Solvents include carbonates such as propylene carbonate, ethylene carbonate, 1,2-butylene carbonate, dimethyl carbonate and diethyl carbonate; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone and 2-heptanone; ethylene glycol, ethylene glycol Polyhydric alcohols such as monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol and dipropylene glycol monoacetate monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether And derivatives thereof; cyclic ethers such as dioxane Ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyacetate, methyl methoxypropionate, ethyl ethoxypropionate, 2- Such as methyl hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, etc. Esters: aromatic hydrocarbons such as toluene and xylene.

  When using a solvent, the use ratio of the solvent is preferably 15 to 1000 parts by weight, more preferably 30 to 500 parts by weight, with respect to 100 parts by weight of the photoacid generator represented by the formula (1) of the present invention. It is. The solvent to be used may be used independently or may use 2 or more types together.

  The energy beam curable composition of the present invention comprises the photoacid generator and a cationically polymerizable compound.

Examples of the cationic polymerizable compound that is a constituent of the energy ray-curable composition include cyclic ethers (epoxides and oxetanes), ethylenically unsaturated compounds (vinyl ether and styrene, etc.), bicycloorthoesters, spiroorthocarbonates, and spiroorthoesters. {JP-A-11-060996, JP-A-09-302269, JP-A-2003-026993, etc.}.

  Known epoxides can be used, and include aromatic epoxides, alicyclic epoxides and aliphatic epoxides.

  Examples of the aromatic epoxide include glycidyl ethers of monovalent or polyvalent phenols (phenol, bisphenol A, phenol novolac and compounds obtained by adducting these alkylene oxides) having at least one aromatic ring.

  As the alicyclic epoxide, a compound obtained by epoxidizing a compound having at least one cyclohexene or cyclopentene ring with an oxidizing agent (3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, etc.) Is mentioned.

  Aliphatic epoxides include aliphatic polyhydric alcohols or polyglycidyl ethers of this alkylene oxide adduct (1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, etc.), aliphatic polybasic acids. Examples thereof include polyglycidyl esters (such as diglycidyl tetrahydrophthalate) and epoxidized products of long chain unsaturated compounds (such as epoxidized soybean oil and epoxidized polybutadiene).

As oxetane, known ones can be used. For example, 3-ethyl-3-hydroxymethyloxetane, 2-ethylhexyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydroxyethyl (3-ethyl-3- Oxetanylmethyl) ether, 2-hydroxypropyl (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, oxetanylsilsesquioxetane, phenol novolac oxetane, etc. Is mentioned.

  As the ethylenically unsaturated compound, known cationic polymerizable monomers and the like can be used, and include aliphatic monovinyl ether, aromatic monovinyl ether, polyfunctional vinyl ether, styrene, and cationic polymerizable nitrogen-containing monomer.

  Examples of the aliphatic monovinyl ether include methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, and cyclohexyl vinyl ether.

  Examples of the aromatic monovinyl ether include 2-phenoxyethyl vinyl ether, phenyl vinyl ether and p-methoxyphenyl vinyl ether.

  Examples of the polyfunctional vinyl ether include butanediol-1,4-divinyl ether and triethylene glycol divinyl ether.

  Examples of styrene include styrene, α-methylstyrene, p-methoxystyrene, and p-tert-butoxystyrene.

  Examples of the cationic polymerizable nitrogen-containing monomer include N-vinylcarbazole and N-vinylpyrrolidone.

  Bicycloorthoesters include 1-phenyl-4-ethyl-2,6,7-trioxabicyclo [2.2.2] octane and 1-ethyl-4-hydroxymethyl-2,6,7-trioxabicyclo. -[2.2.2] octane and the like.

  Examples of the spiro ortho carbonate include 1,5,7,11-tetraoxaspiro [5.5] undecane and 3,9-dibenzyl-1,5,7,11-tetraoxaspiro [5.5] undecane. It is done.

  Spiro orthoesters include 1,4,6-trioxaspiro [4.4] nonane, 2-methyl-1,4,6-trioxaspiro [4.4] nonane and 1,4,6-trioxas. Examples include pyro [4.5] decane.

  Furthermore, a polyorganosiloxane having at least one cationic polymerizable group in one molecule can be used (Japanese Patent Laid-Open No. 2001-348482, Journal of Polym. Sci., Part A, Polym. Chem., Vol. .28, 497 (1990)). These polyorganosiloxanes may be linear, branched or cyclic, or a mixture thereof.

Of these cationically polymerizable compounds, epoxide, oxetane and vinyl ether are preferable, epoxide and oxetane are more preferable, and alicyclic epoxide and oxetane are particularly preferable. Moreover, these cationically polymerizable compounds may be used alone or in combination of two or more.

  The content of the photoacid generator represented by the formula (1) of the present invention in the energy ray curable composition is preferably 0.05 to 20 parts by weight, more preferably 100 parts by weight of the cationic polymerizable compound. Is 0.1 to 10 parts by weight. Within this range, the polymerization of the cationically polymerizable compound is further sufficient, and the physical properties of the cured product are further improved. This content is determined by considering various factors such as the nature of the cationically polymerizable compound, the type of energy beam and the irradiation amount, temperature, curing time, humidity, and coating thickness, and is limited to the above range. Not.

  In the energy beam curable composition of the present invention, if necessary, known additives (sensitizers, pigments, fillers, antistatic agents, flame retardants, antifoaming agents, flow regulators, light stabilizers, An antioxidant, an adhesion-imparting agent, an ion scavenger, a coloring inhibitor, a solvent, a non-reactive resin, a radically polymerizable compound, and the like).

  As the sensitizer, known sensitizers (JP-A-11-279212 and JP-A-09-183960) can be used, and anthracene {anthracene, 9,10-dibutoxyanthracene, 9,10-dimethoxyanthracene. , 9,10-diethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, 9,10-dipropoxyanthracene, etc.}; pyrene; 1,2-benzanthracene; perylene; tetracene; coronene; thioxanthone {thioxanthone, 2 -Methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, 2,4-diethylthioxanthone, etc.}; phenothiazine {phenothiazine, N-methylphenothiazine, N-ethylphenothiazine, N-phenylphenol Xanthone; naphthalene {1-naphthol, 2-naphthol, 1-methoxynaphthalene, 2-methoxynaphthalene, 1,4-dihydroxynaphthalene, 4-methoxy-1-naphthol, etc.}; ketone {dimethoxyacetophenone, di Ethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4′-isopropyl-2-hydroxy-2-methylpropiophenone, 4-benzoyl-4′-methyldiphenyl sulfide, etc.}; carbazole {N-phenylcarbazole, N-ethylcarbazole, poly-N-vinylcarbazole and N-glycidylcarbazole and the like}; chrysene {1,4-dimethoxychrysene and 1,4-di-α-methylbenzyloxychrysene and the like}; phenanthrene {9 -Hydroxyphenanthrene, 9-methoxyphenanthrene, 9-hydroxy-10-methoxyphenanthrene, 9-hydroxy-10-ethoxyphenanthrene, etc.}.

  When it contains a sensitizer, the content of the sensitizer is preferably 1 to 300 parts by weight, more preferably 5 to 200 parts by weight, with respect to 100 parts of the photoacid generator.

  Known pigments can be used as the pigment, and examples include inorganic pigments (such as titanium oxide, iron oxide, and carbon black) and organic pigments (such as azo pigments, cyanine pigments, phthalocyanine pigments, and quinacridone pigments).

  When the pigment is contained, the content of the pigment is preferably 0.5 to 400,000 parts by weight, more preferably 10 to 150,000 parts by weight with respect to 100 parts of the photoacid generator.

  As the filler, known fillers can be used, such as fused silica, crystalline silica, calcium carbonate, aluminum oxide, aluminum hydroxide, zirconium oxide, magnesium carbonate, mica, talc, calcium silicate and lithium aluminum silicate. Can be mentioned.

  When it contains a filler, the content of the filler is preferably 50 to 600,000 parts by weight, more preferably 300 to 200,000 parts by weight with respect to 100 parts of the photoacid generator.

  As the antistatic agent, known antistatic agents can be used, and examples include nonionic antistatic agents, anionic antistatic agents, cationic antistatic agents, amphoteric antistatic agents, and polymeric antistatic agents. .

  When the antistatic agent is contained, the content of the antistatic agent is preferably 0.1 to 20000 parts by weight, more preferably 0.6 to 5000 parts by weight with respect to 100 parts of the photoacid generator.

  As the flame retardant, known flame retardants can be used. Inorganic flame retardant {antimony trioxide, antimony pentoxide, tin oxide, tin hydroxide, molybdenum oxide, zinc borate, barium metaborate, red phosphorus, aluminum hydroxide , Magnesium hydroxide, calcium aluminate, etc.}; bromine flame retardant {tetrabromophthalic anhydride, hexabromobenzene, decabromobiphenyl ether, etc.}; and phosphate ester flame retardant {tris (tribromophenyl) phosphate, etc.} It is done.

  When the flame retardant is contained, the content of the flame retardant is preferably 0.5 to 40000 parts by weight, more preferably 5 to 10000 parts by weight with respect to 100 parts of the photoacid generator.

As the antifoaming agent, known antifoaming agents can be used, such as alcohol defoaming agents, metal soap defoaming agents, phosphate ester defoaming agents, fatty acid ester defoaming agents, polyether defoaming agents, and silicone defoaming agents. And mineral oil defoaming agents.

As the flow control agent, known flow control agents can be used, and examples thereof include hydrogenated castor oil, polyethylene oxide, organic bentonite, colloidal silica, amide wax, metal soap, and acrylate polymer.
As the light stabilizer, known light stabilizers and the like can be used. Ultraviolet absorbing stabilizers {benzotriazole, benzophenone, salicylate, cyanoacrylate and derivatives thereof}; radical scavenging stabilizers {hindered amines, etc.}; and quenching And a type stabilizer {nickel complex etc.}.
As the antioxidant, known antioxidants can be used, and examples include phenolic antioxidants (monophenolic, bisphenolic and polymeric phenolic), sulfur antioxidants and phosphorus antioxidants. It is done.
As the adhesion-imparting agent, a known adhesion-imparting agent can be used, and examples thereof include a coupling agent, a silane coupling agent, and a titanium coupling agent.
As the ion scavenger, known ion scavengers and the like can be used, and organic aluminum (alkoxyaluminum, phenoxyaluminum, etc.) and the like can be mentioned.
Known anti-coloring agents can be used as the anti-coloring agent. In general, antioxidants are effective. Phenol type antioxidants (monophenol type, bisphenol type and high molecular phenol type, etc.), sulfur type oxidation Inhibitors and phosphorus-based antioxidants may be mentioned, but they are hardly effective in preventing coloring during a heat resistance test at high temperatures.

  When containing an antifoaming agent, a flow regulator, a light stabilizer, an antioxidant, an adhesion promoter, an ion scavenger, or an anti-coloring agent, each content is based on 100 parts of the photoacid generator, The amount is preferably 0.1 to 20000 parts by weight, more preferably 0.5 to 5000 parts by weight.

  The solvent is not particularly limited as long as it can be used for dissolving the cationic polymerizable compound and adjusting the viscosity of the energy ray-curable composition, and those mentioned as the solvent for the photoacid generator can be used.

  When the solvent is contained, the content of the solvent is preferably 50 to 2,000,000 parts by weight, more preferably 200 to 500,000 parts by weight with respect to 100 parts of the photoacid generator.

  Non-reactive resins include polyester, polyvinyl acetate, polyvinyl chloride, polybutadiene, polycarbonate, polystyrene, polyvinyl ether, polyvinyl butyral, polybutene, hydrogenated styrene butadiene block copolymer, and (meth) acrylic ester co-polymer. Examples include coalescence and polyurethane. The number average molecular weight of these resins is preferably 1,000 to 500,000, and more preferably 5,000 to 100,000 (the number average molecular weight is a value measured by a general method such as GPC).

  In the case of containing a non-reactive resin, the content of the non-reactive resin is preferably 5 to 400000 parts by weight, more preferably 50 to 150,000 parts by weight with respect to 100 parts of the photoacid generator.

  When a non-reactive resin is contained, it is desirable to dissolve the non-reactive resin in a solvent in advance in order to facilitate dissolution of the non-reactive resin with the cationic polymerizable compound.

  As radically polymerizable compounds, known {Photopolymer social gathering “Photopolymer Handbook” (1989, Industrial Research Committee), General Technology Center “UV / EB Curing Technology” (1982, General Technology Center), Radtech Research Can be used as radically polymerizable compounds such as “UV / EB Curing Materials” (1992, CMC), etc., monofunctional monomer, bifunctional monomer, polyfunctional monomer, epoxy (meth) acrylate, polyester (meth) Acrylate and urethane (meth) acrylate are included.

  When the radically polymerizable compound is contained, the content of the radically polymerizable compound is preferably 5 to 400000 parts by weight, more preferably 50 to 150,000 parts by weight, with respect to 100 parts of the photoacid generator.

  When a radically polymerizable compound is contained, it is preferable to use a radical polymerization initiator that initiates polymerization by heat or light in order to increase the molecular weight of the compound by radical polymerization.

  As the radical polymerization initiator, known radical polymerization initiators can be used, thermal radical polymerization initiators (organic peroxides, azo compounds, etc.) and photo radical polymerization initiators (acetophenone initiators, benzophenone initiators, Michler ketone-based initiator, benzoin-based initiator, thioxanthone-based initiator, acylphosphine-based initiator, etc.).

  When the radical polymerization initiator is contained, the content of the radical polymerization initiator is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight with respect to 100 parts of the radical polymerizable compound. .

  The energy ray-curable composition of the present invention comprises a cationically polymerizable compound, a photoacid generator and, if necessary, a uniform agent at room temperature (about 20 to 30 ° C.) or optionally under heating (about 40 to 90 ° C.). Can be mixed and dissolved, or further kneaded with three rolls or the like.

The energy ray-curable composition of the present invention can be cured by irradiation with energy rays to obtain a cured product.
As the energy ray, any energy ray may be used as long as it has energy that induces decomposition of the photoacid generator of the present invention, but a low pressure, medium pressure, high pressure or ultrahigh pressure mercury lamp, metal halide lamp, LED lamp, xenon lamp, carbon arc. lamps, fluorescent lamps, semiconductor solid-state laser, argon laser, the He-Cd laser, KrF excimer laser, ArF excimer laser or _{F 2} ultraviolet to visible light region derived from a laser or the like: energy ray (wavelength of about 100 to about 800 nm) is preferable. In addition, the radiation which has high energy, such as an electron beam or an X-ray, can also be used for an energy beam.

  The irradiation time of the energy beam is affected by the energy beam intensity and the energy beam permeability to the energy beam curable composition, but about 0.1 to 10 seconds is sufficient at room temperature (about 20 to 30 ° C.). It is. However, it may be preferable to spend more time when energy beam permeability is low or when the energy beam curable composition is thick. Most energy ray-curable compositions are cured by cationic polymerization 0.1 seconds to several minutes after irradiation with energy rays, but if necessary, after irradiation with energy rays, room temperature (about 20 to 30 ° C.) to 200. It is also possible to heat and cure at a temperature of several seconds to several hours.

  Specific applications of the energy ray curable composition of the present invention include paints, coating agents, various coating materials (hard coat, anti-stain coating, anti-fogging coating, touch-resistant coating, optical fiber, etc.), adhesive tape Back coating agent, Release coating material for adhesive labels (release paper, release plastic film, release metal foil, etc.), printing plate, dental material (dental compound, dental composite) ink, inkjet ink, positive Type resist (connecting terminals and wiring pattern formation for manufacturing electronic components such as circuit boards, CSPs, MEMS elements, etc.), resist films, liquid resists, negative resists (surface protective films for semiconductor elements, interlayer insulating films, planarization films) Permanent film materials, etc.), MEMS resist, positive photosensitive materials, negative photosensitive materials, various adhesives (temporary fixing agents for various electronic components, DD adhesive, pickup lens adhesive, FPD functional film (deflection plate, antireflection film, etc. adhesive), holographic resin, FPD material (color filter, black matrix, partition material, photospacer, Ribs, alignment films for liquid crystals, sealants for FPD, etc.), optical members, molding materials (for building materials, optical components, lenses), casting materials, putty, glass fiber impregnating agents, sealing materials, sealing materials, sealing Examples include materials, optical semiconductor (LED) sealing materials, optical waveguide materials, nanoimprint materials, photofabrication materials, and micro stereolithography materials.

  Since the photoacid generator of the present invention generates a strong acid upon irradiation with light, a chemical amplification type known in the art (JP 2003-267968 A, JP 2003-261529 A, JP 2002-193925 A, etc.) is used. It can also be used as a photoacid generator for resist materials.

  As the chemically amplified resist material, (1) a two-component chemically amplified positive resist containing, as essential components, a resin that is soluble in an alkali developer by the action of an acid and a photoacid generator; (2) an alkali developer Soluble resin, a three-component chemical amplification type positive resist containing, as essential components, a dissolution inhibitor that becomes soluble in an alkali developer by the action of an acid and a photoacid generator, and (3) acceptable for an alkali developer. A chemically amplified negative resist containing a cross-linking agent that crosslinks the resin by heat treatment in the presence of an acid and an acid and an insoluble in an alkaline developer and a photoacid generator as an essential component is included.

The chemically amplified positive photoresist composition of the present invention comprises a component (A) comprising a photoacid generator represented by the formula (1) of the present invention, which is a compound that generates an acid upon irradiation with light or radiation. It contains a resin component (B) whose solubility in alkali is increased by the action of an acid.

  In the chemically amplified positive photoresist composition of the present invention, the component (A) may be used in combination with other conventionally known photoacid generators. Examples of other photoacid generators include onium salt compounds, sulfone compounds, sulfonic acid ester compounds, sulfonimide compounds, disulfonyldiazomethane compounds, disulfonylmethane compounds, oxime sulfonate compounds, hydrazine sulfonate compounds, triazine compounds, and nitrobenzyl. In addition to compounds, organic halides, disulfone and the like can be mentioned.

  As other conventionally known photoacid generators, one or more of the group of onium compounds, sulfonimide compounds, diazomethane compounds and oxime sulfonate compounds are preferred.

  When such other conventionally known photoacid generators are used in combination, the ratio of use may be arbitrary, but is usually 100 parts by weight of the total weight of the photoacid generator represented by the above formula (1). The other photoacid generator is 10 to 900 parts by weight, preferably 25 to 400 parts by weight.

  The content of the component (A) is preferably 0.05 to 5% by weight in the solid content of the chemically amplified positive photoresist composition.

<Resin component (B) whose solubility in alkali is increased by the action of acid>
The aforementioned “resin (B) whose solubility in alkali is increased by the action of an acid” (hereinafter referred to as “component (B)”) used in the chemically amplified positive photoresist composition of the present invention. , Novolak resin (B1), polyhydroxystyrene resin (B2), and acrylic resin (B3), or at least one resin selected from the group consisting of these resins, or a mixed resin or copolymer thereof.

[Novolac resin (B1)]
As the novolac resin (B1), a resin represented by the following general formula (b1) can be used.

In the general formula (b1), R ^1b represents an acid dissociable, dissolution inhibiting group, R ^2b and R ^3b each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and n is in parentheses. Represents the number of repeating units in the structure.

Furthermore, ^examples of the acid dissociable, dissolution inhibiting group represented by R ^1b include a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, and a cyclic group having 3 to 6 carbon atoms. Are preferably an alkyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, or a trialkylsilyl group.

Here, specific examples of the acid dissociable, dissolution inhibiting group represented by R ^1b include methoxyethyl group, ethoxyethyl group, n-propoxyethyl group, isopropoxyethyl group, n-butoxyethyl group, isobutoxyethyl. Group, tert-butoxyethyl group, cyclohexyloxyethyl group, methoxypropyl group, ethoxypropyl group, 1-methoxy-1-methyl-ethyl group, 1-ethoxy-1-methylethyl group, tert-butoxycarbonyl group, tert-butoxy group Examples include carbonylmethyl group, trimethylsilyl group, and tri-tert-butyldimethylsilyl group.

[Polyhydroxystyrene resin (B2)]
As the polyhydroxystyrene resin (B2), a resin represented by the following general formula (b4) can be used.

In the general formula (b4), R ^8b represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R ^9b represents an acid dissociable, dissolution inhibiting group, and n represents the number of repeating units in the parenthesis. Represent.

  The alkyl group having 1 to 6 carbon atoms is a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, or a cyclic alkyl group having 3 to 6 carbon atoms, Examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The cyclic alkyl group includes a cyclopentyl group and a cyclohexyl group. Etc.

As the acid dissociable, dissolution inhibiting group represented by R ^9b , the same acid dissociable, dissolution inhibiting groups as those exemplified for R ^1b can be used.

  Furthermore, the polyhydroxystyrene resin (B2) can contain other polymerizable compounds as structural units for the purpose of appropriately controlling physical and chemical properties. Examples of such polymerizable compounds include known radical polymerizable compounds and anionic polymerizable compounds. For example, monocarboxylic acids such as acrylic acid; dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid; methacrylic acid derivatives having a carboxyl group and an ester bond such as 2-methacryloyloxyethyl succinic acid; methyl (meth) acrylate, etc. (Meth) acrylic acid alkyl esters of (meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth) acrylate; dicarboxylic acid diesters such as diethyl maleate; vinyl group-containing fragrances such as styrene and vinyltoluene Aliphatic compounds; vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; nitrile group-containing polymerizable compounds such as acrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride; And the like amide bond-containing polymerizable compounds such as.

[Acrylic resin (B3)]
As the acrylic resin (B3), resins represented by the following general formulas (b5) to (b10) can be used.

In the general formulas (b5) to (b7), R ^{10b to} R ^17b each independently represent a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, or a branched alkyl group having 3 to 6 carbon atoms. Represents a group, a fluorine atom, a linear fluorinated alkyl group having 1 to 6 carbon atoms or a branched fluorinated alkyl group having 3 to 6 carbon atoms, and ^Xb together with the carbon atom to which it is bonded Forming a hydrocarbon ring having 5 to 20 carbon atoms, Y ^b represents an aliphatic cyclic group or an alkyl group which may have a substituent, n represents the number of repeating units of the structure in parentheses, p is an integer of 0 to 4, and q is 0 or 1.

In General Formula (b8), General Formula (b9), and General Formula (b10), R ^18b , R ^20b, and R ^21b each independently represent a hydrogen atom or a methyl group, and in General Formula (b8), R ^19b is independently of each other a hydrogen atom, a hydroxyl group, a cyano group or a COOR ^23b group (where R ^23b is a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms or a branched group having 3 to 4 carbon atoms). Represents a chain alkyl group or a cycloalkyl group having 3 to 20 carbon atoms.) In the general formula (b10), each R ^22b is independently a monovalent alicyclic group having 4 to 20 carbon atoms. A hydrocarbon group or a derivative thereof, or a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms, and at least one of R ^22b is the alicyclic hydrocarbon group or Either its derivatives or any two R ^22b of each other are bonded to each other to form a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof together with the common carbon atom to which each is bonded, and the remaining R ^22b is carbon A linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group having 3 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof is represented.

  Among the components (B), it is preferable to use an acrylic resin (B3).

  Moreover, the polystyrene conversion weight average molecular weight of a component (B) becomes like this. Preferably it is 10,000-600,000, More preferably, it is 50,000-600,000, More preferably, it is 230,000-550,000. is there. By setting it as such a weight average molecular weight, the resin physical property of a resist becomes excellent.

  Furthermore, the component (B) is preferably a resin having a dispersity of 1.05 or more. Here, the “dispersion degree” is a value obtained by dividing the weight average molecular weight by the number average molecular weight. By setting such a degree of dispersion, the resist plating resistance and resin physical properties are excellent.

  The content of the component (B) is preferably 5 to 60% by weight in the solid text of the chemically amplified positive photoresist composition.

<Alkali-soluble resin (C)>
The chemically amplified positive photoresist composition of the present invention preferably further contains an alkali-soluble resin (hereinafter referred to as “component (C)”) in order to improve the resin physical properties of the resist. . The component (C) is preferably at least one selected from the group consisting of novolak resins, polyhydroxystyrene resins, acrylic resins and polyvinyl resins.

  The content of the component (C) is preferably 5 to 95 parts by weight, and more preferably 10 to 90 parts by weight with respect to 100 parts by weight of the component (B). When the amount is 5 parts by weight or more, the resin physical properties of the resist can be improved, and when the amount is 95 parts by weight or less, there is a tendency that film loss during development can be prevented.

<Acid diffusion control agent (D)>
The chemical amplification type positive photoresist composition of the present invention further comprises an acid diffusion control agent (D) (in the present specification, “component (D)”) in order to improve the resist pattern shape, the stability of holding and the like. It is preferable to contain. As the component (D), a nitrogen-containing compound is preferable, and an organic carboxylic acid, an oxo acid of phosphorus, or a derivative thereof can be further contained as necessary.

  In addition, the chemically amplified positive photoresist composition of the present invention may further contain an adhesion assistant in order to improve the adhesion to the substrate. As the adhesion assistant used, a functional silane coupling agent is preferable.

  The chemically amplified positive photoresist composition of the present invention may further contain a surfactant in order to improve coating properties, antifoaming properties, leveling properties and the like.

  In addition, the chemically amplified positive photoresist composition of the present invention may further contain an acid, an acid anhydride, or a high boiling point solvent in order to finely adjust the solubility in an alkali developer.

  In addition, the chemically amplified positive photoresist composition of the present invention basically does not require a sensitizer, but can contain a sensitizer as necessary to complement the sensitivity. As such a sensitizer, conventionally known ones can be used, and specific examples thereof include those described above.

  The amount of these sensitizers used is 5 to 500 parts by weight, preferably 10 to 300 parts by weight, based on 100 parts by weight of the total weight of the photoacid generator represented by the above formula (1).

  In addition, an organic solvent can be appropriately blended in the chemically amplified positive photoresist composition of the present invention for viscosity adjustment. Specific examples of the organic solvent include those described above.

  The amount of these organic solvents used is such that the solid layer concentration is such that the film thickness of the photoresist layer obtained by using the chemically amplified positive photoresist composition of the present invention (for example, spin coating method) is 5 μm or more. Is preferably 30% by weight or more.

  The chemical amplification type positive photoresist composition of the present invention can be prepared, for example, by mixing and stirring the above components by a usual method. If necessary, a disperser such as a dissolver, a homogenizer, or a three roll mill is used. They may be used for dispersion and mixing. Moreover, after mixing, you may further filter using a mesh, a membrane filter, etc.

  The chemically amplified positive photoresist composition of the present invention is suitable for forming a photoresist layer having a thickness of usually 5 to 150 μm, more preferably 10 to 120 μm, and still more preferably 10 to 100 μm on a support. ing. In this photoresist laminate, a photoresist layer made of the chemically amplified positive photoresist composition of the present invention is laminated on a support.

  The support is not particularly limited, and a conventionally known one can be used. Examples thereof include a substrate for electronic parts and a substrate on which a predetermined wiring pattern is formed. Examples of the substrate include a metal substrate such as silicon, silicon nitride, titanium, tantalum, palladium, titanium tungsten, copper, chromium, iron, and aluminum, a glass substrate, and the like. In particular, the chemically amplified positive photoresist composition of the present invention can form a resist pattern satisfactorily even on a copper substrate. As a material for the wiring pattern, for example, copper, solder, chromium, aluminum, nickel, gold, or the like is used.

  The said photoresist laminated body can be manufactured as follows, for example. That is, a desired coating film is formed by applying a solution of a chemically amplified positive photoresist composition prepared as described above onto a support and removing the solvent by heating. As a coating method on the support, methods such as a spin coating method, a slit coating method, a roll coating method, a screen printing method, and an applicator method can be employed. The pre-baking conditions of the coating film of the composition of the present invention vary depending on the type of each component in the composition, the blending ratio, the coating film thickness, etc., but are usually 70 to 150 ° C., preferably 80 to 140 ° C. What is necessary is just about 60 minutes.

  The film thickness of the photoresist layer is usually 5 to 150 μm, preferably 10 to 120 μm, more preferably 10 to 100 μm.

  In order to form a resist pattern using the thus-obtained photoresist laminate, light or radiation, for example, having a wavelength of 300 to 500 nm is applied to the obtained photoresist layer through a mask having a predetermined pattern. Irradiation (exposure) with ultraviolet rays or visible rays may be performed selectively.

Here, the “light” may be light that activates the photoacid generator to generate acid, and includes ultraviolet rays, visible rays, and far ultraviolet rays, and “radiation” means X-rays, electron beams, and the like. Means an ion beam or the like. As a light or radiation source, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, an argon gas laser, an LED lamp, or the like can be used. Moreover, although the amount of radiation irradiation changes with kinds of each component in a composition, a compounding quantity, the film thickness of a coating film, etc., when using an ultrahigh pressure mercury lamp, it is 50-10,000 mJ / cm < ² >, for example.

  Then, after the exposure, the diffusion of the acid is promoted by heating using a known method to change the alkali solubility of the exposed photoresist layer. Next, for example, using a predetermined alkaline aqueous solution as a developer, unnecessary portions are dissolved and removed to obtain a predetermined resist pattern.

  The development time varies depending on the type of each component of the composition, the blending ratio, and the dry film thickness of the composition, but it is usually 1 to 30 minutes, and the development method is the liquid piling method, dipping method, paddle method, spray development method Any of these may be used. After the development, washing with running water is performed for 30 to 90 seconds and dried using an air gun or an oven.

  Forming connection terminals such as metal posts and bumps by embedding a conductor such as metal in the non-resist portion (the portion removed with the alkali developer) of the resist pattern thus obtained, for example, by plating. Can do. The plating method is not particularly limited, and various conventionally known methods can be employed. As the plating solution, solder plating, copper plating, gold plating, or nickel plating solution is particularly preferably used. The remaining resist pattern is finally removed using a stripping solution or the like according to a conventional method.

  The chemically amplified positive photoresist composition of the present invention can also be used as a dry film. This dry film has a protective film formed on both sides of a layer made of the chemically amplified positive photoresist composition of the present invention. The thickness of the layer made of the chemically amplified positive photoresist composition is usually 10 to 150 μm, preferably 20 to 120 μm, more preferably 20 to 80 μm. Moreover, a protective film is not specifically limited, The resin film conventionally used for the dry film can be used. As an example, one may be a polyethylene terephthalate film and the other may be one selected from the group consisting of a polyethylene terephthalate film, a polypropylene film, and a polyethylene film.

  The chemical amplification type positive dry film as described above can be produced, for example, as follows. That is, a solution of a chemically amplified positive photoresist composition prepared as described above is applied onto one protective film, and the solvent is removed by heating to form a desired coating film. The drying conditions vary depending on the type of each component in the composition, the blending ratio, the coating film thickness and the like, but are usually 60 to 100 ° C. and about 5 to 20 minutes.

  In order to form a resist pattern using the thus obtained chemically amplified dry film, one protective film of the chemically amplified positive dry film is peeled off and the exposed surface is directed to the support side described above. Then, after laminating on the support to obtain a photoresist layer, after prebaking to dry the resist, the other protective film may be peeled off.

  In the photoresist layer thus obtained on the support, a resist pattern can be formed in the same manner as described above with respect to the photoresist layer formed by coating directly on the support. .

The chemically amplified negative photoresist composition of the present invention comprises a component (E) comprising a photoacid generator represented by the general formula (1) of the present invention, which is a compound that generates an acid upon irradiation with light or radiation. And an alkali-soluble resin (F) having a phenolic hydroxyl group and a crosslinking agent (G).

Alkali-soluble resin (F) having phenolic hydroxyl group
Examples of the “alkali-soluble resin having a phenolic hydroxyl group” in the present invention (hereinafter referred to as “phenol resin (F)”) include, for example, novolak resin, polyhydroxystyrene, a copolymer of polyhydroxystyrene, hydroxystyrene and styrene. Copolymer of hydroxystyrene, styrene and (meth) acrylic acid derivative, phenol-xylylene glycol condensation resin, cresol-xylylene glycol condensation resin, phenol-dicyclopentadiene condensation resin, and the like. Among these, novolac resin, polyhydroxystyrene, copolymer of polyhydroxystyrene, copolymer of hydroxystyrene and styrene, copolymer of hydroxystyrene, styrene and (meth) acrylic acid derivative, phenol-xylylene glycol Condensed resins are preferred. In addition, these phenol resin (F) may be used individually by 1 type, and may mix and use 2 or more types.

Moreover, the phenolic resin (F) may contain a phenolic low molecular compound as a part of the component.
Examples of the phenolic low molecular weight compound include 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenyl ether, and the like.

Cross-linking agent (G)
The “crosslinking agent” (hereinafter also referred to as “crosslinking agent (G)”) in the present invention is not particularly limited as long as it acts as a crosslinking component (curing component) that reacts with the phenol resin (F). Examples of the crosslinking agent (G) include a compound having at least two or more alkyl etherified amino groups in the molecule, a compound having at least two or more alkyl etherified benzenes in the molecule as a skeleton, An oxirane ring-containing compound, a thiirane ring-containing compound, an oxetanyl group-containing compound, an isocyanate group-containing compound (including a blocked one), and the like can be given.

Of these crosslinking agents (G), compounds having at least two alkyl etherified amino groups in the molecule and oxirane ring-containing compounds are preferred. Furthermore, it is more preferable to use a compound having at least two alkyl etherified amino groups in the molecule and an oxirane ring-containing compound in combination.

The blending amount of the crosslinking agent (G) in the present invention is preferably 1 to 100 parts by weight, more preferably 5 to 50 parts by weight with respect to 100 parts by weight of the phenol resin (F). When the amount of the crosslinking agent (G) is 1 to 100 parts by weight, the curing reaction proceeds sufficiently, and the resulting cured product has a good pattern shape with high resolution, heat resistance and electrical insulation. It is preferable because of its excellent properties.
When the compound having an alkyl etherified amino group and the oxirane ring-containing compound are used in combination, the content ratio of the oxirane ring-containing compound is the sum of the compound having an alkyl etherified amino group and the oxirane ring-containing compound being 100. In the case of weight%, it is preferably 50% by weight or less, more preferably 5 to 40% by weight, and particularly preferably 5 to 30% by weight.
In this case, the obtained cured film is preferable because it is excellent in chemical resistance without impairing high resolution.

Cross-linked fine particles (H)
The chemically amplified negative photoresist composition of the present invention further contains crosslinked fine particles (hereinafter also referred to as “crosslinked fine particles (H)”) in order to improve the durability and thermal shock resistance of the resulting cured product. Can be made.

The average particle size of the crosslinked fine particles (H) is usually 30 to 500 nm, preferably 40 to 200 nm, more preferably 50 to 120 nm.
The method for controlling the particle size of the crosslinked fine particles (H) is not particularly limited. For example, when the crosslinked fine particles are synthesized by emulsion polymerization, the number of micelles during emulsion polymerization is controlled by the amount of the emulsifier used, and the particle size is controlled. Can be controlled.
The average particle diameter of the crosslinked fine particles (H) is a value measured by diluting a dispersion of crosslinked fine particles according to a conventional method using a light scattering flow distribution measuring device or the like.

The amount of the crosslinked fine particles (H) is preferably 0.5 to 50 parts by weight, more preferably 1 to 30 parts by weight with respect to 100 parts by weight of the phenol resin (F). When the blended amount of the crosslinked fine particles (H) is 0.5 to 50 parts by weight, the compatibility or dispersibility with other components is excellent, and the thermal shock resistance and heat resistance of the resulting cured film are improved. be able to.

Adhesion aid In addition, the chemically amplified negative photoresist composition of the present invention may contain an adhesion aid in order to improve the adhesion to the substrate.
Examples of the adhesion assistant include a functional silane coupling agent having a reactive substituent such as a carboxyl group, a methacryloyl group, an isocyanate group, and an epoxy group.

The compounding amount of the adhesion assistant is preferably 0.2 to 10 parts by weight, more preferably 0.5 to 8 parts by weight with respect to 100 parts by weight of the phenol resin (F). A blending amount of the adhesion aid of 0.2 to 10 parts by weight is preferable because it is excellent in storage stability and good adhesion can be obtained.

Solvent Further, the chemically amplified negative photoresist composition of the present invention may contain a solvent for improving the handleability of the resin composition and adjusting the viscosity and storage stability.
The solvent is not particularly limited, but specific examples include those described above.

  Further, the chemically amplified negative photoresist composition of the present invention can contain a sensitizer if necessary. As such a sensitizer, conventionally known ones can be used, and specific examples thereof include those described above.

  The amount of these sensitizers used is 5 to 500 parts by weight, preferably 10 to 300 parts by weight, based on 100 parts by weight of the total weight of the photoacid generator represented by the general formula (1).

Other Additives In addition, the chemically amplified negative photoresist composition of the present invention can contain other additives as necessary so as not to impair the characteristics of the present invention. Examples of such other additives include inorganic fillers, quenchers, leveling agents and surfactants.

The method for preparing the chemically amplified negative photoresist composition of the present invention is not particularly limited, and can be prepared by a known method. It can also be prepared by stirring a sample bottle with each component in it and completely plugged on the wave rotor.

The cured product in the present invention is obtained by curing the chemically amplified negative photoresist composition.
The above-mentioned chemically amplified negative photoresist composition according to the present invention has a high residual film ratio and excellent resolution, and its cured product is excellent in electrical insulation, thermal shock, etc. The cured product can be suitably used as a surface protective film, planarizing film, interlayer insulating film material, etc. for electronic components such as semiconductor elements and semiconductor packages.

In order to form the cured product of the present invention, first, the chemically amplified negative photoresist composition according to the present invention is used as a support (a silicon wafer with a resin-coated copper foil, a copper-clad laminate, a metal sputtered film, Coating onto an alumina substrate and the like, and drying to volatilize the solvent and the like to form a coating film. Then, it exposes through a desired mask pattern, heat processing (henceforth this heat processing is called "PEB") is performed, and reaction with a phenol resin (F) and a crosslinking agent (G) is accelerated | stimulated. Subsequently, it develops with an alkaline developing solution, A desired pattern can be obtained by melt | dissolving and removing an unexposed part. Furthermore, a cured film can be obtained by performing a heat treatment in order to develop insulating film characteristics.

As a method of applying the resin composition to the support, for example, a coating method such as a dipping method, a spray method, a bar coating method, a roll coating method, or a spin coating method can be used. The thickness of the coating film can be appropriately controlled by adjusting the coating means and the solid content concentration and viscosity of the composition solution.
Examples of radiation used for exposure include ultraviolet rays such as low-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, g-line steppers, h-line steppers, i-line steppers, gh-line steppers, and ghi-line steppers, electron beams, and laser beams. . The exposure amount is appropriately selected depending on the light source used, the resin film thickness, and the like. For example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, the resin film thickness is about 100 to 50000 J / m 2 when the resin film thickness is 1 to 50 μm.

After the exposure, the PEB treatment is performed to promote the curing reaction of the phenol resin (F) and the crosslinking agent (G) by the generated acid. The PEB condition varies depending on the blending amount of the resin composition, the used film thickness, etc., but is usually 70 to 150 ° C., preferably 80 to 120 ° C., and about 1 to 60 minutes. Thereafter, development is performed with an alkaline developer, and a desired pattern is formed by dissolving and removing unexposed portions. Examples of the developing method in this case include a shower developing method, a spray developing method, an immersion developing method, and a paddle developing method. The development conditions are usually 20 to 40 ° C. and about 1 to 10 minutes.

Furthermore, in order to sufficiently develop the characteristics as an insulating film after development, the film can be sufficiently cured by heat treatment. Such curing conditions are not particularly limited, but the composition can be cured by heating at a temperature of 50 to 250 ° C. for about 30 minutes to 10 hours depending on the use of the cured product. Moreover, in order to fully advance hardening and to prevent the deformation | transformation of the obtained pattern shape, it can also heat in two steps, for example, at the temperature of 50-120 degreeC in a 1st step, 5 minutes-2 It can also be cured by heating for about an hour and further heating for about 10 minutes to 10 hours at a temperature of 80 to 250 ° C. Under such curing conditions, a general oven, an infrared furnace, or the like can be used as a heating facility.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited by this. In addition, the part in each example shows a weight part.

[Production Example 1]
Synthesis of [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium tris (pentafluoroethyl) trifluorophosphate (P1-FP)

89 parts of dichloromethane solution containing 32.0 parts of (4-phenylthio) phenyl diphenylsulfonium trifluoromethanesulfonate was stirred in a suspension in which 36.8 parts of aluminum chloride, 12.0 parts of acetyl chloride and 200 parts of dichloromethane were mixed. Under cooling, the system temperature was added dropwise so as not to exceed 10 ° C. After completion of the dropwise addition, the reaction was conducted at room temperature for 2 hours, and then the reaction solution was stirred into 300 parts of cold water and mixed well. Subsequently, 32.7 parts of potassium tris (pentafluoroethyl) trifluorophosphate was added, stirred at room temperature for 1 hour, and allowed to stand. The aqueous layer was removed with a separatory funnel, and the organic layer was washed 5 times with 300 parts of water, and then the solvent was removed under reduced pressure using a rotary evaporator to obtain a yellow liquid. Subsequently, the solvent was washed with a toluene / hexane solution, impurities were removed, and dried under reduced pressure at 50 ° C. to obtain [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium tris (pentafluoroethyl) trifluoro as a yellow viscous product. 47.4 parts of phosphate were obtained (90% yield).
The product was identified by ¹ H-NMR and infrared absorption spectroscopy (IR). { ¹ H-NMR: d6-dimethylsulfoxide; δ (ppm) 8.0 (2H, d), 7.7 to 7.9 (12H, m), 7.5 to 7.6 (4H, m), 2.6 (3H, s). IR (KBr tablet method): CF bond characteristic absorption; around 1200 cm ⁻¹ . }

[Production Example 2]
Synthesis of [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium tetrakis (pentafluorophenyl) borate (P1-FB)

[4- (4-Acetyl) phenylthio] was prepared in the same manner as in Production Example 1, except that 32.7 parts of potassium tris (pentafluoroethyl) trifluorophosphate was changed to 46.3 parts of lithium tetrakis (pentafluorophenyl) borate. ] 60.4 parts of phenyl diphenylsulfonium tetrakis (pentafluorophenyl) borate were obtained (yield 90%).
The product was identified by ¹ H-NMR and infrared absorption spectroscopy (IR). { ¹ H-NMR: d6-dimethylsulfoxide; δ (ppm) 8.0 (2H, d), 7.7 to 7.9 (12H, m), 7.5 to 7.6 (4H, m), 2.6 (3H, s). IR (KBr tablet method): BF bond characteristic absorption; around 980 cm ⁻¹ . }

[Production Example 3]
Synthesis of [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium tris (trifluoromethanesulfonyl) methide (P1-C)

[4- (4-Acetyl) phenylthio] was prepared in the same manner as in Production Example 1 except that 32.7 parts of potassium tris (pentafluoroethyl) trifluorophosphate was changed to 28.2 parts of tris (trifluoromethanesulfonyl) methide lithium. 45.6 parts of phenyl diphenylsulfonium tris (trifluoromethanesulfonyl) methide were obtained (90% yield).
The product was identified by ¹ H-NMR and infrared absorption spectroscopy (IR). { ¹ H-NMR: d6-dimethylsulfoxide; δ (ppm) 8.0 (2H, d), 7.7 to 7.9 (12H, m), 7.5 to 7.6 (4H, m), 2.6 (3H, s). IR (KBr tablet method): CF bond characteristic absorption; around 1200 cm ⁻¹ . }

[Production Example 4]
Synthesis of [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium hexafluoroantimonate (P1-Sb)

[4- (4-Acetyl) phenylthio] phenyl diphenylsulfonium was prepared in the same manner as in Production Example 1 except that 32.7 parts of potassium tris (pentafluoroethyl) trifluorophosphate was changed to 18.6 parts of potassium hexafluoroantimonate. 35.9 parts of hexafluoroantimonate were obtained (90% yield).
The product was identified by ¹ H-NMR and infrared absorption spectroscopy (IR). { ¹ H-NMR: d6-dimethylsulfoxide; δ (ppm) 8.0 (2H, d), 7.7 to 7.9 (12H, m), 7.5 to 7.6 (4H, m), 2.6 (3H, s). IR (KBr tablet method): Sb-F binding property absorption; around 650 cm ⁻¹ . }

[Production Example 5]
Synthesis of [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium hexafluorophosphate (P1-P)

[4- (4-Acetyl) phenylthio] phenyl diphenylsulfonium was prepared in the same manner as in Production Example 1 except that 32.7 parts of potassium tris (pentafluoroethyl) trifluorophosphate was changed to 12.4 parts of potassium hexafluorophosphate. 30.9 parts of hexafluorophosphate were obtained (90% yield).
The product was identified by ¹ H-NMR and infrared absorption spectroscopy (IR). { ¹ H-NMR: d6-dimethylsulfoxide; δ (ppm) 8.0 (2H, d), 7.7 to 7.9 (12H, m), 7.5 to 7.6 (4H, m), 2.6 (3H, s). IR (KBr tablet method): PF bond characteristic absorption; around 840 cm ⁻¹ . }

[Production Example 6]
Synthesis of [4- (4-acetyl) phenylthio] phenyl diphenylsulfonium trifluoromethanesulfonate (P1-TF)

[4- (4-Acetyl) phenylthio] phenyl diphenylsulfonium was prepared in the same manner as in Production Example 1 except that 32.7 parts of potassium tris (pentafluoroethyl) trifluorophosphate was changed to 12.7 parts of potassium trifluoromethanesulfonate. 31.1 parts of trifluoromethanesulfonate were obtained (yield 90%).
The product was identified by ¹ H-NMR and infrared absorption spectroscopy (IR). { ¹ H-NMR: d6-dimethylsulfoxide; δ (ppm) 8.0 (2H, d), 7.7 to 7.9 (12H, m), 7.5 to 7.6 (4H, m), 2.6 (3H, s). IR (KBr tablet method): CF bond characteristic absorption; around 1200 cm ⁻¹ . }

[Production Example 7]
Synthesis of [4- (4-benzoyl) phenylthio] phenyl diphenylsulfonium tris (hexafluoroethyl) trifluorophosphate (P2-FP)

[4- (4-Benzoyl) phenylthio] phenyl diphenylsulfonium tris (hexafluoroethyl) trifluorophosphate 50. Except for changing 12.0 parts of acetyl chloride to 21.7 parts of benzoyl chloride, 9 parts were obtained (90% yield).
The product was identified by ¹ H-NMR and infrared absorption spectroscopy (IR). { ¹ H-NMR: d6-dimethylsulfoxide; δ (ppm) 7.9 to 8.2 (4H, m), 7.7 to 7.9 (15H, m), 7.5 to 7.7 (4H , M). IR (KBr tablet method): CF bond characteristic absorption; around 1200 cm ⁻¹ . }

[Production Example 8]
Synthesis of [4- (4-benzoyl) phenylthio] phenyl diphenylsulfonium tetrakis (hexafluorophenyl) borate (P2-BP)

Production Example except that 12.0 parts of acetyl chloride is changed to 21.7 parts of benzoyl chloride and 32.7 parts of potassium tris (pentafluoroethyl) trifluorophosphate is changed to 46.3 parts of lithium tetrakis (pentafluorophenyl) borate. In the same manner as in Example 1, 63.8 parts of [4- (4-benzoyl) phenylthio] phenyl diphenylsulfonium tetrakis (hexafluorophenyl) borate was obtained (yield 90%).
The product was identified by ¹ H-NMR and infrared absorption spectroscopy (IR). { ¹ H-NMR: d6-dimethylsulfoxide; δ (ppm) 7.9 to 8.2 (4H, m), 7.7 to 7.9 (15H, m), 7.5 to 7.7 (4H , M). IR (KBr tablet method): BF bond characteristic absorption; around 980 cm ⁻¹ . }

[Comparative Example 1]
Synthesis of 4- (phenylthio) phenyldiphenylsulfonium tris (pentafluoroethyl) trifluorophosphate (RS-1FP) While stirring 12.1 parts of diphenyl sulfoxide, 9.3 parts of diphenyl sulfide and 43.0 parts of methanesulfonic acid, 7.9 parts of acetic anhydride was added dropwise thereto, reacted at 40-50 ° C. for 5 hours, cooled to room temperature (about 25 ° C.), and this reaction solution was diluted with 20% potassium tris (pentafluoroethyl) trifluorophosphate. The solution was poured into 121 parts of an aqueous solution and stirred at room temperature (about 25 ° C.) for 1 hour to precipitate a yellow slightly viscous oil. This oily substance was extracted with ethyl acetate, the organic layer was washed several times with water, the solvent was distilled off from the organic layer, and the resulting residue was dissolved by adding toluene. The mixture was stirred well for 1 hour and allowed to stand. After 1 hour, since the solution was separated into two layers, the upper layer was removed by liquid separation. When hexane was added to the remaining lower layer and mixed well at room temperature (about 25 ° C.), pale yellow crystals were precipitated. This was filtered off and dried under reduced pressure to obtain 4- (phenylthio) phenyldiphenylsulfonium tris (pentafluoroethyl) trifluorophosphate in a yield of 60%.
The product was identified by ¹ H-NMR {d6-dimethylsulfoxide, δ (ppm) 7.7 to 7.9 (12H, m), 7.5 to 7.6 (5H, m), 7.4 (2H, d)}. In addition, absorption of C—F bond was confirmed in the vicinity of 1200 cm ⁻¹ by infrared spectroscopic analysis (KBr tablet method).

[Comparative Example 2]
Synthesis of diphenyl-2-thioxanthonylsulfonium tris (pentafluoroethyl) trifluorophosphate (RS2-FP) 15.0 parts of 2- (phenylthio) thioxanthone, 41.9 parts of diphenyliodonium hexafluorophosphate, copper benzoate (II ) After 0.4 parts and 300 parts of chlorobenzene were uniformly mixed and reacted at 120 to 125 ° C. for 3 hours, the reaction solution was cooled to room temperature (about 25 ° C.) and poured into 300 parts of distilled water to produce a product. Was precipitated. This was filtered, and the residue was washed with water until the pH of the filtrate became neutral. The residue was dried under reduced pressure, 100 parts of diethyl ether was added, and the mixture was dispersed in diethyl ether with an ultrasonic cleaner and allowed to stand for about 15 minutes. Then, the operation of removing the supernatant was repeated 3 times to wash the produced solid. Subsequently, the solid was transferred to a rotary evaporator and the solvent was distilled off to obtain a yellow solid. This yellow solid was dissolved in 770 parts of dichloromethane, charged into 342 parts of 10% aqueous potassium tris (pentafluoroethyl) trifluorophosphate, and stirred for 2 hours at room temperature (about 25 ° C.). The organic layer was washed several times with water. By washing and drying under reduced pressure, diphenyl-2-thioxanthonylsulfonium tris (pentafluoroethyl) trifluorophosphate was obtained in a yield of 98%.
The product was identified by ¹ H-NMR {d6-dimethylsulfoxide, δ (ppm) 8.7 (1H, s), 8.5 (1H, d), 8.3 (1H, d), 8. 1 (2H, d), 7.8-8.0 (11H, m), 7.7 (1H, t)}. In addition, absorption of C—F bond was confirmed in the vicinity of 1200 cm ⁻¹ by infrared absorption analysis (KBr tablet method).

[Comparative Example 3]
Synthesis of 4- (phenylthio) phenyldiphenylsulfonium tetrakis (pentafluorophenyl) borate (RS1-FB) “121 parts of 20% aqueous tris (pentafluoroethyl) potassium trifluorophosphate” was changed to “10% tetrakis (pentafluorophenyl) borane” 4- (phenylthio) phenyldiphenylsulfonium tetrakis (pentafluorophenyl) borate was obtained in a yield of 60% in the same manner as in Comparative Example 1 except that the acid was changed to 342.9 parts of lithium acid.
The product was identified by ¹ H-NMR {d6-dimethylsulfoxide, δ (ppm) 7.72-7.87 (12H, m), 7.54-7.63 (5H, m), 7.42. (2H, d)}. Further, absorption of BC bond was confirmed in the vicinity of 980 cm ⁻¹ by infrared absorption spectroscopic analysis (KBr tablet method).

[Comparative Example 4]
CPI-110A {4- (phenylthio) phenyldiphenylsulfonium hexafluoroantimonate, manufactured by San Apro Co., Ltd.} was used as a comparative sulfonium salt.

[Comparative Example 5]
CPI-110P {4- (phenylthio) phenyldiphenylsulfonium hexafluorophosphate, manufactured by San Apro Co., Ltd.} was used as a comparative sulfonium salt.

(Preparation of energy ray-curable composition and evaluation thereof)
The photoacid generator of the present invention and the compound of the comparative example were dissolved in solvent-1 (propylene carbonate) at the blending amounts shown in Table 1, and then the epoxide (3,4-epoxycyclohexylmethyl-), which is a cationically polymerizable compound. 3,4-epoxycyclohexanecarboxylate, manufactured by Daicel Chemical Industries, Ltd., Celoxide 2021P) was uniformly mixed in the blending amount (parts by weight) shown in Table 1, and energy ray curable compositions (Examples C1 to C7, Comparative Examples). C1-C5) were prepared.

  In addition, the sulfonium salt obtained in Production Example 5 and Comparative Example 5 is hexafluorophosphate, and Tris (pentafluoroethyl) trifluorophosphate of Production Examples 1-4, 7, 8, and Comparative Examples 1-4. , Tetrakis (pentafluorophenyl) borate, tris (trifluoromethanesulfonyl) methidoate and hexafluoroantimonate have lower acid strength and lower activity against cationic polymerization. A lot. Along with this, the amount of the solvent was increased.

<Photosensitivity (photocurability)>
The energy ray-curable composition obtained above was applied to a polyethylene terephthalate (PET) film with an applicator (25 μm). The PET film was irradiated with ultraviolet light having a wavelength limited by a filter using an ultraviolet irradiation device. The filter used was an IRCF02 filter (manufactured by Eye Graphics Inc., a filter that cuts light of less than 340 nm). After irradiation, the film hardness after 40 minutes was measured with pencil hardness (JIS K5600-5-4: 1999) and evaluated according to the following criteria (coating thickness after curing was about 25 μm). It is shown in Table 2. The higher the pencil hardness, the better the photocurability of the energy beam curable composition, that is, the better the polymerization initiation ability of the sulfonium salt to the cationically polymerizable compound (photosensitivity of the sulfonium salt).

(Evaluation criteria)
◎: Pencil hardness is 2H or more ○: Pencil hardness is H to B
(Triangle | delta): Pencil hardness is 2B-4B
×: There is liquid to tack, and pencil hardness cannot be measured

(Ultraviolet light irradiation conditions)
・ Ultraviolet irradiation device: Belt conveyor type UV irradiation device (manufactured by Eye Graphics Co., Ltd.)
・ Lamp: 1.5kW high pressure mercury lamp ・ Filter: IRCF02 filter (manufactured by Eye Graphics Co., Ltd.)
Illuminance (measured with a 365 nm head illuminometer): 145 mW / cm ²

-Integrated light quantity (measured with 365nm head illuminometer):
Condition-1: 140 mJ / cm ²
Condition-2: 170 mJ / cm ²
Condition-3: 200 mJ / cm ²

<Storage stability>
The energy ray-curable composition obtained above was heated at 80 ° C. under light shielding and stored for 1 month, and then the viscosity of the blended sample before and after heating was measured and evaluated according to the following criteria. The storage stability is better as the viscosity does not increase.
(Evaluation criteria)
X: Viscosity change after heating is 1.5 times or more.
○: Viscosity change after heating is less than 1.5 times.

  As can be seen from the results in Table 2, it was found that the sulfonium salt of the present invention was superior in curing performance (photosensitivity) of the cationically polymerizable compound under ultraviolet light of 365 nm or more as compared with the comparative sulfonium salt. .

[Evaluation of Positive Photoresist Composition]
<Preparation of sample for evaluation>
As shown in Table 3, 1 part by weight of a component (A) that is a photoacid generator, 40 parts by weight of a resin represented by the following chemical formula (Resin-1), and a resin component (C) as a resin component (B) 60 parts by weight of novolak resin obtained by addition condensation of m-cresol and p-cresol in the presence of formaldehyde and an acid catalyst are uniformly dissolved in solvent-2 (propylene glycol monomethyl ether acetate), and a membrane having a pore diameter of 1 μm The mixture was filtered through a filter to prepare positive photoresist compositions (Examples P1 to P6) having a solid concentration of 40% by weight.
Moreover, the comparative example was similarly performed by the compounding quantity shown in Table 3, and the positive photoresist composition (Comparative Examples P1-P4) was prepared.

<Sensitivity evaluation>
The positive resist compositions prepared in Examples P1 to P6 and Comparative Examples P1 to P4 were spin-coated on a silicon wafer substrate, and then dried to obtain a photoresist layer having a thickness of about 20 μm. This resist layer was pre-baked at 130 ° C. for 6 minutes using a hot plate. After pre-baking, pattern exposure (i-line) was performed using TME-150RSC (manufactured by Topcon Corporation), and post-exposure heating (PEB) was performed at 75 ° C. for 5 minutes using a hot plate. Thereafter, a development process for 5 minutes was performed by an immersion method using a 2.38 wt% tetramethylammonium hydroxide aqueous solution, washed with running water, and blown with nitrogen to obtain a 10 μm line and space (L & S) pattern. Further, below that, the minimum exposure amount at which no residue of this pattern was observed, that is, the minimum essential exposure amount (corresponding to the sensitivity) necessary for forming the resist pattern was measured.

<Storage stability evaluation>
In addition, using the chemically amplified positive resist composition prepared above, the photosensitivity (sensitivity) was evaluated as described above immediately after preparation and after storage for 1 month at 40 ° C., and the storage stability was determined according to the following criteria. It was judged.
○: Sensitivity change after 1 month storage at 40 ° C is less than 5% of the sensitivity immediately after preparation ×: Sensitivity change after storage at 40 ° C for 1 month is 5% or more of the sensitivity immediately after preparation

<Pattern shape evaluation>
Through the above operation, the lower side dimension La and the upper side dimension Lb of the cross section of the 10 μm L & S pattern formed on the silicon wafer substrate were measured using a scanning electron microscope, and the pattern shape was judged according to the following criteria. The results are shown in Table 4.
A: 0.90 ≦ Lb / La ≦ 1
○: 0.85 ≦ Lb / La <0.90
X: Lb / La <0.85

  As shown in Table 4, the chemically amplified positive photoresist compositions of Examples P1 to P6 are more sensitive than the case of using a conventional photoacid generator as in Comparative Examples P1 to P4, and stored. It turns out that it is excellent in stability and pattern shape.

[Evaluation of negative photoresist composition]
<Preparation of sample for evaluation>
As shown in Table 5, 1 part by weight of the component (E) that is a photoacid generator and a component (F) that is a phenol resin are copolymers (p-hydroxystyrene / styrene = 80/20 (molar ratio)). 100 parts by weight of Mw = 10,000) and 20 parts by weight of hexamethoxymethylmelamine (manufactured by Sanwa Chemical Co., Ltd., trade name “Nicalak MW-390”) as a crosslinking agent (G) are crosslinked fine particles. As component (H), a copolymer comprising butadiene / acrylonitrile / hydroxybutyl methacrylate / methacrylic acid / divinylbenzene = 64/20/8/6/2 (% by weight) (average particle size = 65 nm, Tg = −38 ° C. ) As a component (I) which is an adhesion assistant, 5 parts by weight of γ-glycidoxypropyltrimethoxysilane (manufactured by Chisso Corporation, trade name “S510”) , Solvent -3 homogeneously dissolved in ethyl lactate () 145 parts by weight, the negative photoresist composition of the present invention (Examples N1 to N6) was prepared.
Moreover, the comparative example was similarly performed by the compounding quantity shown in Table 5, and the negative photoresist composition (comparative example N1-N4) was prepared.

<Sensitivity evaluation>
Each composition was spin-coated on a silicon wafer substrate, and then heat-dried at 110 ° C. for 3 minutes using a hot plate to obtain a resin coating film having a thickness of about 20 μm. Then, pattern exposure (i line | wire) was performed using TME-150RSC (made by Topcon Corporation), and the post-exposure heating (PEB) for 3 minutes was performed at 110 degreeC with the hotplate. Thereafter, a development process for 2 minutes was performed by an immersion method using a 2.38 wt% tetramethylammonium hydroxide aqueous solution, washed with running water, and blown with nitrogen to obtain a 10 μm line and space pattern. Further, the minimum essential exposure amount (corresponding to the sensitivity) necessary for forming a pattern having a remaining film ratio of 95% or more indicating the ratio of the remaining film before and after development was measured.

<Storage stability evaluation>
In addition, using the chemically amplified negative resist composition prepared above, the photosensitivity (sensitivity) was evaluated as described above immediately after preparation and after storage for 1 month at 40 ° C., and the storage stability was determined according to the following criteria. It was judged.
○: Sensitivity change after 1 month storage at 40 ° C is less than 5% of the sensitivity immediately after preparation ×: Sensitivity change after storage at 40 ° C for 1 month is 5% or more of the sensitivity immediately after preparation

<Pattern shape evaluation>
By the above operation, the lower side dimension La and the upper side dimension Lb of the shape cross section of the 20 μm L & S pattern formed on the silicon wafer substrate were measured using a scanning electron microscope, and the pattern shape was judged according to the following criteria. The results are shown in Table 6.
A: 0.90 ≦ La / Lb ≦ 1
○: 0.85 ≦ La / Lb <0.90
X: La / Lb <0.85

  As shown in Table 6, the chemically amplified negative photoresist compositions of Examples N1 to N6 are more sensitive than the case of using a conventional photoacid generator as in Comparative Examples N1 to N4, and stored. It turns out that it is excellent in stability and pattern shape.

  The sulfonium salt of the present invention comprises a coating material, a coating agent, various coating materials (hard coat, antifouling coating material, anti-fogging coating material, touch-proof coating material, optical fiber, etc.), a back treatment agent for an adhesive tape, and a release sheet for an adhesive label. Release coating material (release paper, release plastic film, release metal foil, etc.), printing plate, dental material (dental compound, dental composite) ink, inkjet ink, positive resist (circuit board, CSP, MEMS element) Connection terminal and wiring pattern formation, etc. for electronic component manufacturing, etc.), resist film, liquid resist, negative resist (permanent film materials such as surface protective films for semiconductor elements, interlayer insulation films, planarization films, etc.), for MEMS Resist, positive photosensitive material, negative photosensitive material, various adhesives (various electronic component temporary fixing agents, HDD adhesives, pickup adhesives) Adhesive, FPD functional film (deflection plate, antireflection film, etc.), holographic resin, FPD material (color filter, black matrix, partition material, photospacer, rib, alignment film for liquid crystal , FPD sealant, etc.), optical members, molding materials (for building materials, optical components, lenses), casting materials, putty, glass fiber impregnating agents, sealing materials, sealing materials, sealing materials, optical semiconductors (LEDs) ) It is suitably used as a photoacid generator for use in encapsulants, optical waveguide materials, nanoimprint materials, photofabrication, and micro stereolithography materials.

Claims (11)

A sulfonium salt represented by the following general formula (1).

[R in the formula (1) represents a methyl group, R-CO- group is located at the ^4-position, the number ^m 1 ~m ³ of R 1 to R ³ are each 0, X ^- is SbF _{6 ^{-, PF 6 -, BF 4}} -, ((CF 3) 2 C 6 H 3) 4 B -, (C 6 F 5) 4 Ga -, ((CF 3) 2 C 6 H 3) 4 Ga -, Trifluoromethanesulfonate anion, nonafluorobutanesulfonate anion, methanesulfonate anion, butanesulfonate anion, camphorsulfonate anion, benzenesulfonate anion, p-toluenesulfonate anion, (CF ₃ SO ₂ ) ₃ C ⁻ , and _{(CF 3 SO 2) 2 N} - represents a monovalent polyatomic anion selected from the group consisting of anion represented by. ] A photoacid generator comprising the sulfonium salt according to claim 1 . An energy ray-curable composition comprising the photoacid generator according to claim 2 and a cationically polymerizable compound. A cured product obtained by curing the energy beam curable composition according to claim 3 . A chemical amplification type positive photo, comprising: a component (A) comprising the photoacid generator according to claim 2; and a component (B) which is a resin whose solubility in alkali is increased by the action of an acid. Resist composition. It said component (B) is a novolac resin (B1), a polyhydroxystyrene resin (B2), and those comprising at least one resin selected from the group consisting of acrylic resin (B3), according to claim 5 Chemically amplified positive photoresist composition. The chemically amplified positive photoresist composition according to claim 5 or 6 , further comprising an alkali-soluble resin (C) and an acid diffusion controller (D). A laminating step of laminating a 10 to 150 μm thick photoresist layer made of the chemically amplified positive photoresist composition according to claim 5 on a support; A resist pattern comprising: an exposure step of selectively irradiating light or radiation to the photoresist laminate, and a development step of developing the photoresist laminate to obtain a resist pattern after the exposure step Method. A chemical amplification comprising a component (E) comprising the photoacid generator according to claim 2 , a component (F) which is an alkali-soluble resin having a phenolic hydroxyl group, and a crosslinking agent component (G). Type negative photoresist composition. The chemically amplified negative photoresist composition according to claim 9 , further comprising a crosslinked fine particle component (H). A cured product obtained by curing the chemically amplified negative photoresist composition according to claim 9 or 10 .