Sulfonium salt, photoacid generator, curable composition and resist composition

Abstract

Provided are: a novel sulfonium salt highly photosensitive to active energy rays, in particular, i-rays or h-rays; and a novel photoacid generator which is highly photosensitive to i-rays or h-rays, and contains a sulfonium salt that is highly soluble in a solvent and a cationically polymerizable compound such as an epoxy compound, and has excellent storage stability in the formulation. The present invention pertains to a sulfonium salt represented by general formula (1), and a photoacid generator characterized by containing said sulfonium salt.

Description

Technical Field

[0001] The present invention relates first to sulfonium salts, second to photoacid generators, and more particularly to specific sulfonium salts suitable for curing cationic polymerizable compounds by the action of active energy rays such as light, electron beams or X-rays. The present invention relates third to a curable composition containing the photoacid generator and a cured body obtained by curing the same. The present invention relates fourth to a chemically amplified positive photoresist composition containing the photoacid generator and a method for producing a resist pattern using the same. The present invention relates fifth to a chemically amplified negative photoresist composition containing the photoacid generator and a cured body obtained by curing the same.

Background Art

[0002] A photoacid generator is a general term for compounds that decompose upon irradiation with active energy rays such as light, electron beams or X-rays to generate an acid. The acid generated by irradiation with active energy rays is used as an active species in various reactions such as polymerization, crosslinking, and deprotection reactions. Specifically, it includes polymerization of cationic polymerizable compounds in fields such as paints, adhesives, and stereolithography, photolithography in the manufacture of electronic components and semiconductor element formation (crosslinking reaction in the presence of a phenol resin and a crosslinking agent, and further acid-catalyzed deprotection reaction of a polymer having a protecting group introduced into an alkali-soluble resin). In recent years, the manufacture of electronic components and semiconductor element formation have been actively carried out by making full use of photolithography technology using photoresists. In particular, i-line (light beam with a wavelength of 365 nm) is widely used as an active energy ray in the manufacture of various precision parts such as semiconductor packages. This is because a low-cost medium-pressure / high-pressure mercury lamp with good emission intensity can be used as the irradiation light source. In addition, medium-pressure and high-pressure mercury lamps are most commonly used in fields such as paints, adhesives, and stereolithography other than photolithography. Recently, LED lamps have been used because of their advantages such as energy saving and long life. Not only LED lamps with emission wavelengths in the conventional i-line region (360 nm to 390 nm), but also LED lamps with longer wavelengths such as the h-line region (400 nm to 420 nm) and the visible light region with higher light transmittance have been used, and the photosensitive wavelengths required for photoacid generators cover a wide range.

[0003] Among existing photoacid generators, triarylsulfonium salts (Patent Document 1), phenacylsulfonium salts having a naphthalene skeleton (Patent Document 2), and dialkylbenzylsulfonium salts (Patent Document 3) have extremely low photosensitivity, and a sensitizer needs to be used in combination to enhance the sensitivity. However, many sensitizers have low compatibility with resins and photoacid generators, and there are cases where their use is restricted. The triarylsulfonium salts described in Patent Documents 4 to 7 enhance photosensitivity without using a sensitizer in combination by greatly increasing the light absorption of i-line, h-line, or visible light through the expansion of the π-conjugated system. However, when the light absorption is large, when used as a curable composition or a photoresist composition, the irradiated light is strongly absorbed only on the surface of the composition, and there are cases where the light does not penetrate deep into the composition, resulting in poor reactivity. Therefore, ideally, a photoacid generator having high photosensitivity without increasing light absorption is desired.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above background, a first object of the present invention is to provide a new sulfonium salt having high photosensitivity without significantly increasing light absorption. A second object of the present invention is to provide a new photoacid generator comprising a sulfonium salt having high photosensitivity and excellent storage stability in a formulation with a cationically polymerizable compound such as an epoxy compound. A third object of the present invention is to provide an energy ray-curable composition and a cured body using the above photoacid generator. A fourth object of the present invention is to provide a chemically amplified positive photoresist composition and a method for producing the same using the above photoacid generator. A fifth object of the present invention is to provide a chemically amplified negative photoresist composition and a cured body thereof using the above photoacid generator.

Means for Solving the Problems

[0006] The present inventors synthesized a sulfonium salt represented by the following general formula (1) and found that it is suitable for each of the above objects. That is, the present invention provides a sulfonium salt represented by the following general formula (1).

[0007]

Chemical Formula

[0008] [In formula (1), R1 and R2 each independently represent an aryl group having 6 to 14 carbon atoms, and a part of the hydrogen atoms of these aryl groups may be substituted with a substituent (t). The substituent (t) is an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 10 carbon atoms, and these substituents (t) are directly bonded to R1 and R2 by a single bond, or via any of the groups represented by -SO-, -SO 2 -, or -CO-. A1 and A2 each independently represent a hydrogen atom, a branched alkyl group having 3 to 7 carbon atoms, a branched alkoxy group having 3 to 7 carbon atoms, a tertiary silyl group having 3 to 9 carbon atoms, or a tertiary siloxy group having 3 to 9 carbon atoms, provided that A1 and A2 are not both hydrogen atoms at the same time. T1 and T2 each independently represent an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, a silyl group having 3 to 9 carbon atoms, or a siloxy group having 3 to 9 carbon atoms. m1 and m2 each represent the number of T1 and T2, respectively, m1 is an integer from 0 to 3, and m2 is an integer from 0 to 4. L is a group represented by -O-, -S-, -SO-, -SO 2 -, or -CO-, S is a sulfur atom, O is an oxygen atom, C is a carbon atom, X - represents a monovalent polyatomic anion.]

[0009] The present invention is also a photoacid generator characterized by containing the above-mentioned sulfonium salt.

[0010] The present invention is also an energy ray-curable composition characterized by containing the above photoacid generator and a cationically polymerizable compound.

[0011] The present invention is further a cured body characterized by being obtained by curing the above energy ray-curable composition.

[0012] The present invention is further a chemically amplified positive photoresist composition characterized by containing the above photoacid generator and a component (B) which is a resin whose solubility in alkali increases by the action of an acid.

[0013] Furthermore, the present invention provides a method for producing a resist pattern, comprising: a laminating step of laminating a photoresist layer having a thickness of 5 to 150 μm composed of the above-described chemically amplified positive photoresist composition to obtain a photoresist laminate; an exposure step of selectively irradiating the photoresist laminate with light or radiation; and a developing step of developing the photoresist laminate after the exposure step to obtain a resist pattern.

[0014] Furthermore, the present invention provides a chemically amplified negative photoresist composition, comprising the above-described photoacid generator, a component (F) which is an alkali-soluble resin having a phenolic hydroxyl group, and a crosslinking agent component (G).

[0015] Furthermore, the present invention provides a cured product obtained by curing any of the above-described chemically amplified negative photoresist compositions.

Advantages of the Invention

[0016] The sulfonium salt of the present invention is excellent in 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 solvents and epoxy compounds, and has excellent storage stability in a blend with a cationically polymerizable compound such as an epoxy compound. Further, since the sulfonium salt of the present invention has high photosensitivity without increasing the light absorption of ultraviolet light, it has excellent transparency and reactivity when used as a curable composition or a photoresist composition. When used for curing a cationically polymerizable compound, the photoacid generator of the present invention is excellent in curability by the action of ultraviolet light, particularly i-line and h-line, and can cure the cationically polymerizable compound without using a sensitizer. Since the energy ray curable composition of the present invention contains the above-described photoacid generator, it can be cured with ultraviolet light. Further, the energy ray curable composition of the present invention has high storage stability and does not require the use of a sensitizer, and thus is excellent in cost and workability. Furthermore, since the energy ray curable composition of the present invention has high transparency to ultraviolet light, it is also excellent in curability for a thick film. Since the cured body of the present invention can be obtained without using a sensitizer, there are no problems such as coloring and deterioration caused by the remaining sensitizer. Since the chemically amplified positive photoresist composition and the chemically amplified negative photoresist composition of the present invention contain the above-mentioned photoacid generator, it is possible to obtain a resist that is highly sensitive to i-line and h-line (pattern formation is possible with a lower exposure amount compared to conventional ones). In addition, 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. Furthermore, since the chemically amplified positive photoresist composition and the chemically amplified negative photoresist composition of the present invention have high ultraviolet light transmittance, they are also excellent in photoreactivity (sensitivity) in thick films.

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described in detail.

[0018] The sulfonium salt contained in the photoacid generator of the present invention is represented by the following formula (1).

[0019]

Chemical formula

[0020] [In formula (1), R1 and R2 each independently represent an aryl group having 6 to 14 carbon atoms, and a part of the hydrogen atoms of these aryl groups may be substituted with a substituent (t). The substituent (t) is an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 10 carbon atoms, and these substituents (t) are directly bonded to R1 and R2 by a single bond, or -SO-, -SO 2- or may be bonded via any of the groups represented by -CO-. A1 and A2 are each independently a hydrogen atom, a branched alkyl group having 3 to 7 carbon atoms, a branched alkoxy group having 3 to 7 carbon atoms, a tertiary silyl group having 3 to 9 carbon atoms, or a tertiary siloxy group having 3 to 9 carbon atoms, provided that A1 and A2 are not simultaneously hydrogen atoms. T1 and T2 each independently represent an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, a silyl group having 3 to 9 carbon atoms, or a siloxy group having 3 to 9 carbon atoms. m1 and m2 each represent the number of T1 and T2, respectively, m1 is an integer from 0 to 3, and m2 is an integer from 0 to 4. L is -O-, -S-, -SO-, -SO 2 - or a group represented by -CO-, S is a sulfur atom, O is an oxygen atom, C is a carbon atom, X - represents a monovalent polyatomic anion.]

[0021] Among R1 and R2, examples of the aryl group include aryl groups having 6 to 14 carbon atoms (such as phenyl, tolyl, dimethylphenyl, biphenylyl, naphthyl, fluorenyl, fluorenonyl, anthracenyl, anthraquinonyl, etc.).

[0022] R1 and R2 may be the same, different, or partially different, but are preferably the same.

[0023] In the aryl groups of R1 and R2, some of the hydrogen atoms may be substituted with a substituent (t), and this substituent (t) is an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 10 carbon atoms. These substituents (t) are directly bonded to R1 and R2 by a single bond, or via -SO-, -SO 2 - or may be bonded via any of the groups represented by -CO-.

[0024] Among the substituents (t), examples of the alkyl group having 1 to 8 carbon atoms include linear alkyl groups (such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-octyl), branched alkyl groups (such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, and isooctadecyl), and cycloalkyl groups (such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl).

[0025] Among the substituents (t), examples of the aryl group having 6 to 10 carbon atoms include phenyl, tolyl, dimethylphenyl, and naphthyl.

[0026] Among A1 and A2, examples of the branched alkyl group having 3 to 7 carbon atoms include isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, and isohexyl.

[0027] Among A1 and A2, examples of the branched alkoxy group having 3 to 7 carbon atoms include isopropoxy, isobutoxy, sec-butoxy, and tert-butoxy.

[0028] Among A1 and A2, examples of the tertiary silyl group having 3 to 9 carbon atoms include trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, and triisopropylsilyl.

[0029] Among A1 and A2, examples of the tertiary siloxy group having 3 to 9 carbon atoms include trimethylsiloxy, triethylsiloxy, tert-butyldimethylsiloxy, and triisopropylsiloxy.

[0030] A1 and A2 may be the same or different from each other, but they are not hydrogen atoms at the same time. Preferably, at least one of A1 or A2 is a group selected from a tert-butyl group, a tert-butoxy group, and a trimethylsiloxy group, and more preferably, it is a tert-butyl group from the viewpoint of availability of industrial raw materials.

[0031] Among T1 and T2, examples of the alkyl group having 1 to 7 carbon atoms include linear alkyl groups (such as methyl, ethyl, propyl, butyl, pentyl, and benzyl), branched alkyl groups (such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, and isohexyl), and cycloalkyl groups (such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl).

[0032] Among T1 and T2, examples of the alkoxy group having 1 to 7 carbon atoms include linear or branched alkoxy groups (such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, and hexyloxy).

[0033] Among T1 and T2, examples of the silyl group having 3 to 9 carbon atoms include trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, and triisopropylsilyl.

[0034] Among T1 and T2, examples of the siloxy group having 3 to 9 carbon atoms include trimethylsiloxy, triethylsiloxy, tert-butyldimethylsiloxy, and triisopropylsiloxy.

[0035] T1 and T2 may be the same as each other, different from each other, or partially different from each other.

[0036] m1 represents the number of T1 and is an integer from 0 to 3, preferably from 0 to 2, more preferably 0 or 1. m2 represents the number of T2 and is an integer from 0 to 4, preferably from 0 to 2.

[0037] L is a group represented by -O-, -S-, -SO-, -SO 2 -, or -CO-, preferably -S-, -SO-, or -SO 2 -. S represents a sulfur atom, O represents an oxygen atom, and C represents a carbon atom.

[0038] X - is an univalent polyatomic anion without limitation and is an anion corresponding to the acid (HX) generated by irradiating the sulfonium salt of the present invention with active energy rays (such as visible light, ultraviolet rays, electron beams, and X-rays). However, MY a - , (Rf) b PF 6-b - , R 3 c BY 4-c - , R 3 c GaY 4-c - , R 4 SO 3 - , (R 4 SO 2 ) 3 C - or (R 4 SO 2 ) 2 N - represented anions are preferred.

[0039] M represents a phosphorus atom, a boron atom, or an antimony atom. Y represents a halogen atom (a fluorine atom is preferred).

[0040] Rf represents an alkyl group in which 80 mol% or more of the hydrogen atoms are substituted with fluorine atoms (preferably an alkyl group having 1 to 8 carbon atoms). Examples of the alkyl group to be made 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 cycloalkyl groups (such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl). The proportion of hydrogen atoms of these alkyl groups substituted with fluorine atoms in Rf is preferably 80 mol% or more, more preferably 90% or more, and particularly preferably 100% based on the number of moles of hydrogen atoms the original alkyl group had. When the substitution ratio by fluorine atoms is within these preferred ranges, the photosensitivity of the sulfonium salt becomes even better. Particularly preferred Rf includes 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 thus may be the same or different from each other.

[0041] P represents a phosphorus atom, and F represents a fluorine atom.

[0042] R 3represents a phenyl group in which some of the hydrogen atoms are substituted with at least one element or electron-withdrawing group. Examples of such an element include halogen atoms, such as fluorine atom, chlorine atom, and bromine atom. Examples of electron-withdrawing groups include trifluoromethyl group, nitro group, and cyano group. Among these, a phenyl group in which one hydrogen atom is substituted with a fluorine atom or a trifluoromethyl group is preferred. c R 3 are independent of each other, and thus may be the same or different from each other.

[0043] B represents a boron atom, and Ga represents a gallium atom.

[0044] R 4 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. The alkyl group and the perfluoroalkyl group may be linear, branched, or cyclic, and the aryl group may be unsubstituted or may have a substituent.

[0045] 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, and more preferably 4.

[0046] MY a - Examples of the anion represented by include SbF 6 - , PF 6 - and BF 4 - and anions represented by etc.

[0047] (Rf) b PF 6-b - Examples of the anion represented by include (CF 3 CF 2 ) 2 PF 4 - , (CF 3 CF2 ) 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 anions represented by (CF 3 CF 2 CF 2 CF 2 ) 3 PF 3 - 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 PF 4 - ,(CF 3 ) 2 CFCF 2 ) 3 PF 3 - and (CF 3 ) 2 CFCF 2 ) 2 PF 4 - are preferred anions, and (CF 3 CF 2 ) 3 PF 3 - ,(CF 3 CF 2 CF 2 CF 2 ) 3 PF 3 -、 are particularly preferred.

[0048] R 3 c BY 4-c - Examples of the anion represented by are (C 6 F 5 ) 4 B - ,(CF 3 ) 2 C 6 H 3 ) 4 B - ,(CF 3 C 6 H 4 ) 4 B - ,(C 6 F 5 ) 2 BF 2 - ,C 6 F 5 BF 3 - and (C 6 H 3 F 2 )4 B - Anions represented by etc. are exemplified. Among these, (C 6 F 5 ) 4 B - 、(C 6 H 5 )(C 6 F 5 ) 3 B - And ((CF 3 ) 2 C 6 H 3 ) 4 B - The represented anions are preferred.

[0049] R 3 c GaY 4-c - As the anions represented by, (C 6 F 5 ) 4 Ga - 、((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 - Anions represented by etc. are exemplified. Among these, (C 6 F 5 ) 4 Ga - And ((CF 3 ) 2 C 6 H 3 ) 4 Ga- An anion represented by the following formula is preferred.

[0050] R 4 SO 3 - Examples of the anion represented by the following formula include trifluoromethanesulfonate anion, pentafluoroethanesulfonate anion, heptafluoropropanesulfonate anion, nonafluorobutanesulfonate anion, pentafluorophenylsulfonate anion, p-toluenesulfonate anion, benzenesulfonate anion, camphorsulfonate anion, methanesulfonate anion, ethanesulfonate anion, propanesulfonate anion, butanesulfonate anion, and the like. Among these, trifluoromethanesulfonate anion, nonafluorobutanesulfonate anion, methanesulfonate anion, camphorsulfonate anion, benzenesulfonate anion, and p-toluenesulfonate anion are preferred.

[0051] (R 4 SO 2 ) 3 C - Examples of the anion represented by the following formula include (CF 3 SO 2 ) 3 C - , (C 2 F 5 SO 2 ) 3 C - , (C 3 F 7 SO 2 ) 3 C - and (C 4 F 9 SO 2 ) 3 C - and the like.

[0052] (R 4 SO 2 ) 2 N - Examples of the anion represented by the following formula include (CF 3 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 - and anions represented by the like are exemplified.

[0053] As the monovalent polyatomic anion (X - ), MY a - , (Rf) b PF 6-b - , R 3 c BY 4-c - , R 3 c GaY 4-c - , R 4 SO 3 - , (R 4 SO 2 ), 3 C - or (R 4 SO 2 ), 2 N - In addition to the anions represented by the like, perhalate ions (ClO 4 - , BrO 4 - etc.), halogenated sulfonate ions (FSO 3 - , ClSO 3 - etc.), sulfate ions (CH 3 SO 4 - , CF 3 SO 4 - , HSO 4 - etc.), carbonate ions (HCO 3 - , CH3 CO 3 - etc.), aluminate ions (AlCl 4 - , AlF 4 - etc.), hexafluorobismuthate ions (BiF 6 - ), carboxylate ions (CH 3 COO - , CF 3 COO - , C 6 H 5 COO - , CH 3 C 6 H 4 COO - , C 6 F 5 COO - , CF 3 C 6 H 4 COO - etc.), arylborate ions (B(C 6 H 5 )) 4 - , CH 3 CH 2 CH 2 CH 2 B(C 6 H 5 )) 3 - etc.), thiocyanate ions (SCN - ) and nitrate ions (NO 3 - ) etc. can be used.

[0054] Sulfonium salts can be produced by the production method described below.

[0055] <Production Method> The method shown by the following reaction formula can be mentioned (for example, the method described in the 4th edition of the Experimental Chemistry Course, Volume 24, 1992, published by Maruzen Co., Ltd., page 376, Japanese Patent Laid-Open No. 7-329399, Japanese Patent Laid-Open No. 8-165290, Japanese Patent Laid-Open No. 10-212286, or Japanese Patent Laid-Open No. 10-7680, etc.).

[0056] [Chemical formula]

[0057] In the above reaction formula, R1, R2, A1, A2, T1, T2, L, S, O, X - , m1 and m2 are the same as defined in general formula (1). H represents a hydrogen atom. HX’ represents the conjugate acid of a monovalent polyatomic anion. From the viewpoints of availability, acid stability, and reaction yield, methanesulfonic acid, perfluoroalkylsulfonic acid, and sulfuric acid are preferred as HX’. The dehydrating agent represents, for example, phosphoric anhydride, acetic anhydride, concentrated sulfuric acid, or perfluoroalkylsulfonic anhydride, etc. The monovalent polyatomic anion (X’ - ) can be exchanged with other anions (X - ) of the present invention by, for example, a metathesis reaction as described above. MX is a salt of an alkali metal (such as lithium, sodium, and potassium) cation and other anions of the present invention {for example, MY , (Rf) a - , PF b , R 6-b - , BY 3 c , R 4-c - , R 3 c , GaY 4-c - , R 4 , SO 3 - , (R 4 , SO 2 ) 3 , C - or (R 4 , SO 2 ) 2 , N - and so on).

[0058] In the above reaction formula, the first-stage reaction may be carried out without a solvent, or may be carried out in an organic solvent (such as acetonitrile, tetrahydrofuran, dioxane, ethanol, acetone, dichloromethane, chloroform, etc.) if necessary. The reaction temperature is about 0°C to 105°C.

[0059] The second-stage reaction may be carried out following the first-stage reaction, or may be carried out after isolating (and purifying if necessary) the reaction intermediate (G2). The reaction intermediate (G2) is mixed and stirred with an aqueous solution of a salt (MX) of an alkali metal cation and the anion used in the present invention to carry out a metathesis reaction. The precipitated solid is filtered, or the separated oily substance is extracted with an organic solvent and the organic solvent is removed, whereby the sulfonium salt of the present invention is obtained as a solid or a viscous liquid. The obtained solid or viscous liquid can be washed with a suitable organic solvent if necessary, or can be purified by a recrystallization method or a column chromatography method.

[0060] The chemical structure of the sulfonium salt of the present invention can be identified by general analytical methods (for example, 1 H-, 11 B-, 13 C-, 19 F-, 31 P-nuclear magnetic resonance spectrum, infrared absorption spectrum, and / or elemental analysis, etc.).

[0061] The photoacid generator of the present invention is characterized by containing a sulfonium salt represented by the general formula (1). However, other conventionally known photoacid generators may also be contained and used.

[0062] When containing other photoacid generators, the content (mol%) of the other photoacid generators is preferably 0.1 to 100, more preferably 0.5 to 50, based on the total number of moles of the sulfonium salt represented by the general formula (1) of the present invention.

[0063] Examples of other photoacid generators include conventionally known salts of onium salts (such as sulfonium, iodonium, selenium, ammonium, and phosphonium), transition metal complex ions, and anions.

[0064] When using the photoacid generator of the present invention, in order to facilitate dissolution in a cationically polymerizable compound or a chemically amplified resist composition, it may be dissolved in advance in a solvent that does not inhibit polymerization, crosslinking, deprotection reaction, etc.

[0065] Examples of the solvent 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; polyhydric alcohols such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol, and dipropylene glycol monoacetate, and their derivatives such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or monophenyl ether; cyclic ethers such as dioxane; esters such as 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, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, β-propiolactone, β-butyrolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone; aromatic hydrocarbons such as toluene and xylene.

[0066] When using a solvent, the proportion of the solvent used is preferably 15 to 1000 parts by weight, more preferably 30 to 500 parts by weight, based on 100 parts by weight of the photoacid generator comprising the sulfonium salt of the present invention. The solvent to be used may be used alone or in combination of two or more kinds.

[0067] The energy ray-curable composition of the present invention comprises the above photoacid generator and a cationically polymerizable compound.

[0068] Examples of the cationically polymerizable compound which is a constituent component of the energy ray-curable composition include cyclic ethers (such as epoxides and oxetanes), ethylenically unsaturated compounds (such as vinyl ethers and styrenes), bicyclic orthoesters, spiro orthocarbonates, and spiro orthoesters (see JP-A-11-060996, JP-A-09-302269, JP-A-2003-026993, etc.).

[0069] As the epoxide, known ones can be used, including aromatic epoxides, alicyclic epoxides, and aliphatic epoxides.

[0070] Examples of the aromatic epoxide include glycidyl ethers of monovalent or polyvalent phenols having at least one aromatic ring (such as phenol, bisphenol A, phenol novolak, and compounds obtained by adding alkylene oxides thereto).

[0071] Examples of the alicyclic epoxide include compounds obtained by epoxidizing a compound having at least one cyclohexene or cyclopentene ring with an oxidizing agent (such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, etc.).

[0072] Examples of the aliphatic epoxide include polyglycidyl ethers of aliphatic polyhydric alcohols or their alkylene oxide adducts (such as 1,4-butanediol diglycidyl ether and 1,6-hexanediol diglycidyl ether), polyglycidyl esters of aliphatic polybasic acids (such as diglycidyl tetrahydrophthalate), and epoxidized products of long-chain unsaturated compounds (such as epoxidized soybean oil and epoxidized polybutadiene).

[0073] As the oxetane, known ones etc. 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, oxetanyl silsesquioxetane, and phenol novolak oxetane etc. can be mentioned.

[0074] As the ethylenically unsaturated compound, known cationically polymerizable monomers etc. can be used, and aliphatic monovinyl ethers, aromatic monovinyl ethers, polyfunctional vinyl ethers, styrenes, and cationically polymerizable nitrogen-containing monomers are included.

[0075] Examples of the aliphatic monovinyl ether include methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, and cyclohexyl vinyl ether etc.

[0076] Examples of the aromatic monovinyl ether include 2-phenoxyethyl vinyl ether, phenyl vinyl ether, and p-methoxyphenyl vinyl ether etc.

[0077] Examples of the polyfunctional vinyl ether include 1,4-butanediol divinyl ether and triethylene glycol divinyl ether etc.

[0078] Examples of styrenes include styrene, α-methylstyrene, p-methoxystyrene, p-tert-butoxystyrene, and the like.

[0079] Examples of cationically polymerizable nitrogen-containing monomers include N-vinylcarbazole and N-vinylpyrrolidone.

[0080] Examples of bicyclic orthoesters 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.

[0081] Examples of spiro orthocarbonates include 1,5,7,11-tetraoxaspiro[5.5]undecane and 3,9-dibenzyl-1,5,7,11-tetraoxaspiro[5.5]undecane.

[0082] Examples of spiro orthoesters include 1,4,6-trioxaspiro[4.4]nonane, 2-methyl-1,4,6-trioxaspiro[4.4]nonane, and 1,4,6-trioxaspiro[4.5]decane.

[0083] Furthermore, a polyorganosiloxane having at least one cationically polymerizable group in one molecule can be used (described in, for example, JP-A-2001-348482, Journal of Polym. Sci., Part A, Polym. Chem., Vol. 28, 497 (1990), etc.). These polyorganosiloxanes may be linear, branched, cyclic, or a mixture thereof.

[0084] Among these cationically polymerizable compounds, epoxides, oxetanes, and vinyl ethers are preferred, more preferably epoxides and oxetanes, and particularly preferably alicyclic epoxides and oxetanes. These cationically polymerizable compounds may be used alone or in combination of two or more.

[0085] The content of the photoacid generator containing the sulfonium salt of the present invention in the energy ray curable composition is preferably 0.05 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the cationic polymerizable compound. When it is within this range, the polymerization of the cationic polymerizable compound becomes more sufficient, and the physical properties of the cured body become better. Note that this content is determined by considering various factors such as the properties of the cationic polymerizable compound, the type and irradiation amount of the energy ray, temperature, curing time, humidity, and the thickness of the coating film, and is not limited to the above range.

[0086] In the energy ray curable composition of the present invention, known additives (sensitizers, pigments, fillers, antistatic agents, flame retardants, defoaming agents, flow regulators, light stabilizers, antioxidants, adhesion imparting agents, ion scavengers, anti-coloring agents, solvents, non-reactive resins, radical polymerizable compounds, etc.) can be contained as necessary.

[0087] As the sensitizer, known sensitizers (such as those disclosed in JP-A-11-279212 and JP-A-09-183960) can be used, including 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-phenylphenothiazine, etc.}; xanthone; naphthalene {1-naphthol, 2-naphthol, 1-methoxynaphthalene, 2-methoxynaphthalene, 1,4-dihydroxynaphthalene, 4-methoxy-1-naphthol, etc.}; ketone {dimethoxyacetophenone, diethoxyacetophenone, 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, N-glycidylcarbazole, etc.}; chrysene {1,4-dimethoxychrysene, 1,4-di-α-methylbenzyloxychrysene, etc.}; phenanthrene {9-hydroxyphenanthrene, 9-methoxyphenanthrene, 9-hydroxy-10-methoxyphenanthrene, 9-hydroxy-10-ethoxyphenanthrene, etc.}, and the like.

[0088] When the sensitizer is contained, the content of the sensitizer is preferably 1 to 300 parts by weight, more preferably 5 to 200 parts by weight, based on 100 parts by weight of the photoacid generator of the present invention.

[0089] As the pigment, known pigments and the like can be used, including 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), and the like.

[0090] When a 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, based on 100 parts of the photoacid generator of the present invention.

[0091] As the filler, known fillers and the like can be used, and examples thereof include fused silica, crystalline silica, calcium carbonate, aluminum oxide, aluminum hydroxide, zirconium oxide, magnesium carbonate, mica, talc, calcium silicate, and lithium aluminum silicate.

[0092] When a filler is contained, the content of the filler is preferably 50 to 600,000 parts by weight, more preferably 300 to 200,000 parts by weight, based on 100 parts of the photoacid generator of the present invention.

[0093] As the antistatic agent, known antistatic agents and the like can be used, and examples thereof include nonionic antistatic agents, anionic antistatic agents, cationic antistatic agents, amphoteric antistatic agents, and polymer antistatic agents.

[0094] When an antistatic agent is contained, the content of the antistatic agent is preferably 0.1 to 20,000 parts by weight, more preferably 0.6 to 5,000 parts by weight, based on 100 parts of the photoacid generator of the present invention.

[0095] As the flame retardant, known flame retardants and the like can be used, and examples thereof include inorganic flame retardants {antimony trioxide, antimony pentoxide, tin oxide, tin hydroxide, molybdenum oxide, zinc borate, barium metaborate, red phosphorus, aluminum hydroxide, magnesium hydroxide, and calcium aluminate, etc.}; bromine flame retardants {tetrabromo phthalic anhydride, hexabromobenzene, and decabromodiphenyl ether, etc.}; and phosphate ester flame retardants {tris(tribromophenyl) phosphate, etc.}.

[0096] When a flame retardant is contained, the content of the flame retardant is preferably 0.5 to 40,000 parts by weight, more preferably 5 to 10,000 parts by weight, based on 100 parts of the photoacid generator of the present invention.

[0097] As the defoaming agent, known defoaming agents and the like can be used, and examples include alcohol defoaming agents, metal soap defoaming agents, phosphate ester defoaming agents, fatty acid ester defoaming agents, polyether defoaming agents, silicone defoaming agents, and mineral oil defoaming agents.

[0098] As the flow regulator, known flow regulators and the like can be used, and examples 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, and examples include ultraviolet absorption type stabilizers {benzotriazole, benzophenone, salicylate, cyanoacrylate, and their derivatives, etc.}; radical scavenging type stabilizers {hindered amine, etc.}; and quenching type stabilizers {nickel complex, etc.}. As the antioxidant, known antioxidants and the like can be used, and examples include phenolic antioxidants (monophenolic, bisphenolic, and high molecular phenolic, etc.), sulfur-based antioxidants, and phosphorus-based antioxidants. As the adhesion promoter, known adhesion promoters and the like can be used, and examples include coupling agents, silane coupling agents, and titanium coupling agents. As the ion supplement agent, known ion supplement agents and the like can be used, and examples include organic aluminum (alkoxy aluminum, phenoxy aluminum, etc.). As the anti-coloring agent, known anti-coloring agents can be used. Generally, antioxidants are effective, and examples include phenolic antioxidants (monophenolic, bisphenolic, and high molecular phenolic, etc.), sulfur-based antioxidants, and phosphorus-based antioxidants. However, they have little effect on preventing coloring during the heat resistance test at high temperatures.

[0099] When containing a defoaming agent, a flow regulator, a light stabilizer, an antioxidant, an adhesion promoter, an ion supplement agent, or an anti-coloring agent, the content of each is preferably 0.1 to 20,000 parts by weight, more preferably 0.5 to 5,000 parts by weight, based on 100 parts of the photoacid generator of the present invention.

[0100] As the solvent, there is no limitation as long as it can be used for dissolving the cationically polymerizable compound and adjusting the viscosity of the energy ray-curable composition, and those mentioned as the solvent for the above photoacid generator can be used.

[0101] When containing a solvent, the content of the solvent is preferably 50 to 2,000,000 parts by weight, more preferably 200 to 500,000 parts by weight, based on 100 parts of the photoacid generator of the present invention.

[0102] Examples of the non-reactive resin include polyester, polyvinyl acetate, polyvinyl chloride, polybutadiene, polycarbonate, polystyrene, polyvinyl ether, polyvinyl butyral, polybutene, hydrogenated styrene-butadiene block copolymer, copolymer of (meth)acrylate ester, and polyurethane. The number average molecular weight of these resins is preferably 1,000 to 500,000, more preferably 5,000 to 100,000 (the number average molecular weight is a value measured by a general method such as GPC).

[0103] When containing a non-reactive resin, the content of the non-reactive resin is preferably 5 to 400,000 parts by weight, more preferably 50 to 150,000 parts by weight, based on 100 parts of the photoacid generator of the present invention.

[0104] When adding a non-reactive resin, in order to facilitate dissolution of the non-reactive resin with the cationically polymerizable compound etc., it is desirable to dissolve it in a solvent in advance.

[0105] As the radically polymerizable compound, known radically polymerizable compounds {such as those edited by the Photopolymer Symposium "Photopolymer Handbook" (1989, Industrial Research Society), edited by the General Technology Center "UV·EB Curing Technology" (1982, General Technology Center), edited by the Radtech Research Group "UV·EB Curing Materials" (1992, CMC)} etc. can be used, and include monofunctional monomers, bifunctional monomers, polyfunctional monomers, epoxy (meth)acrylate, polyester (meth)acrylate, and urethane (meth)acrylate.

[0106] When containing a radically polymerizable compound, the content of the radically polymerizable compound is preferably 5 to 400,000 parts by weight, more preferably 50 to 150,000 parts by weight, based on 100 parts of the photoacid generator of the present invention.

[0107] When containing a radically polymerizable compound, in order to increase the molecular weight thereof by radical polymerization, it is preferable to use a radical polymerization initiator that initiates polymerization by heat or light.

[0108] As the radical polymerization initiator, known radical polymerization initiators and the like can be used, including thermal radical polymerization initiators (organic peroxides, azo compounds, etc.) and photo radical polymerization initiators (acetophenone-based initiators, benzophenone-based initiators, Michler's ketone-based initiators, benzoin-based initiators, thioxanthone-based initiators, acylphosphine-based initiators, etc.).

[0109] When containing a radical polymerization initiator, 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, based on 100 parts of the radically polymerizable compound.

[0110] The energy ray curable composition of the present invention can be prepared by uniformly mixing and dissolving a cationically polymerizable compound, a photoacid generator and, if necessary, additives at room temperature (about 20 to 30 ° C) or, if necessary, by heating (about 40 to 90 ° C), or further kneading with a three-roll mill or the like.

[0111] The energy ray curable composition of the present invention can be cured by irradiating with energy rays to obtain a cured body. As the energy rays, any rays may be used as long as they have the energy to induce the decomposition of the photoacid generator of the present invention. However, low-pressure, medium-pressure, high-pressure or ultra-high-pressure mercury lamps, metal halide lamps, LED lamps, xenon lamps, carbon arc lamps, fluorescent lamps, semiconductor solid lasers, argon lasers, He-Cd lasers, KrF excimer lasers, ArF excimer lasers or F 2Energy rays in the ultraviolet to visible light region (wavelength: about 100 to about 800 nm) obtained from a laser or the like are preferred. Note that radiation having high energy such as an electron beam or X-rays can also be used as the energy rays.

[0112] The irradiation time of the energy rays is affected by the intensity of the energy rays and the permeability of the energy rays to the energy ray-curable composition, but at room temperature (about 20 to 30 °C), about 0.1 second to about 10 seconds is sufficient. However, when the permeability of the energy rays is low or the film thickness of the energy ray-curable composition is thick, it may be preferable to take more time. Most energy ray-curable compositions cure by cationic polymerization within 0.1 second to several minutes after the energy ray irradiation. However, if necessary, after the energy ray irradiation, it is also possible to perform after-curing by heating at room temperature (about 20 to 30 °C) to 200 °C for several seconds to several hours.

[0113] Specific applications of the energy ray-curable composition of the present invention include paints, coating agents, various coating materials (hard coats, stain-resistant coating materials, anti-fog coating materials, corrosion-resistant coating materials, optical fibers, etc.), back surface treatment agents for adhesive tapes, release coating materials for release sheets for adhesive labels (release papers, release plastic films, release metal foils, etc.), printed boards, dental materials (dental formulations, dental composites), inks, inkjet inks, positive resists (for forming connection terminals and wiring patterns in the manufacture of electronic components such as circuit boards, CSPs, and MEMS elements), resist films, liquid resists, negative resists (permanent film materials such as surface protection films, interlayer insulating films, and planarization films for semiconductor elements, etc.), resists for MEMS, positive photosensitive materials, negative photosensitive materials, various adhesives (temporary fixing agents for various electronic components, adhesives for HDDs, adhesives for pickup lenses, adhesives for functional films (deflection plates, anti-reflection films, etc.) for FPDs, etc.), resins for holography, FPD materials (color filters, black matrices, partition materials, photo spacers, ribs, alignment films for liquid crystals, sealants for FPDs, etc.), optical members, molding materials (for building materials, optical parts, lenses), casting materials, putties, glass fiber impregnants, caulking materials, sealing materials, encapsulating materials for optical semiconductors (LEDs), optical waveguide materials, nanoimprint materials, materials for optical molding, and materials for micro optical molding, etc.

[0114] Since the photoacid generator of the present invention generates a strong acid upon light irradiation, it can also be used as a photoacid generator for known (such as JP-A-2003-267968, JP-A-2003-261529, JP-A-2002-193925, etc.) chemically amplified resist materials.

[0115] Chemically amplified resist materials include (1) a two-component chemically amplified positive resist having a resin that becomes soluble in an alkaline developer by the action of an acid and a photoacid generator as essential components, (2) a three-component chemically amplified positive resist having a resin soluble in an alkaline developer, a dissolution inhibitor that becomes soluble in an alkaline developer by the action of an acid, and a photoacid generator as essential components, and (3) a chemically amplified negative resist having a resin soluble in an alkaline developer, a crosslinking agent that crosslinks the resin and makes it insoluble in an alkaline developer by heat treatment in the presence of an acid, and a photoacid generator as essential components.

[0116] The chemically amplified positive photoresist composition of the present invention comprises a component (A) containing a photoacid generator of the present invention which is a compound that generates an acid upon irradiation with light or radiation, and a resin component (B) whose solubility in alkali increases by the action of an acid.

[0117] In the chemically amplified positive photoresist composition of the present invention, component (A) may be used in combination with other conventionally known photoacid generators. Examples of other photoacid generators include, for example, onium salt compounds, sulfone compounds, sulfonic acid ester compounds, sulfonimide compounds, disulfonyldiazomethane compounds, disulfonylmethane compounds, oxime sulfonate compounds, hydrazine sulfonate compounds, triazine compounds, nitrobenzyl compounds, and in addition, organic halides, disulfones, etc.

[0118] As other conventionally known photoacid generators, preferably, one or more of the group consisting of onium compounds, sulfonimide compounds, diazomethane compounds, and oxime sulfonate compounds are preferred.

[0119] When using such other conventionally known photoacid generators in combination, the usage ratio may be arbitrary, but usually, based on 100 parts by weight of the total weight of the sulfonium salt represented by the above general formula (1), the other photoacid generator is 10 to 900 parts by weight, preferably 25 to 400 parts by weight.

[0120] The content of the above component (A) is preferably 0.05 to 5% by weight in the solid content of the chemically amplified positive photoresist composition.

[0121] <The resin component (B) whose solubility in alkali increases by the action of an acid> The "resin (B) whose solubility in alkali increases by the action of an acid" (referred to as "component (B)" in this specification) used in the chemically amplified positive photoresist composition of the present invention is at least one resin selected from the group consisting of a novolak resin (B1), a polyhydroxystyrene resin (B2), and an acrylic resin (B3), or a mixed resin or copolymer thereof.

[0122] [Novolak resin (B1)] As the novolak resin (B1), a resin represented by the following general formula (b1) can be used.

[0123] [Chemical formula]

[0124] In the above general formula (b1), R 1b represents an acid-dissociable dissolution-inhibiting group, and R 2b , R 3b each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and n represents the number of repeating units of the structure in parentheses.

[0125] Furthermore, as the acid-dissociable dissolution-inhibiting group represented by the above R 1b , a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, a cyclic alkyl group having 3 to 6 carbon atoms, a tetrahydropyranyl group, a tetrahydrofuranyl group, or a trialkylsilyl group is preferable.

[0126] Here, the above R 1bSpecific examples of the acid-dissociable dissolution-inhibiting group represented by [the formula] include a methoxyethyl group, an ethoxyethyl group, an n-propoxyethyl group, an isopropoxyethyl group, an n-butoxyethyl group, an isobutoxyethyl group, a tert-butoxyethyl group, a cyclohexyloxyethyl group, a methoxypropyl group, an ethoxypropyl group, a 1-methoxy-1-methylethyl group, a 1-ethoxy-1-methylethyl group, a tert-butoxycarbonyl group, a tert-butoxycarbonylmethyl group, a trimethylsilyl group, and a tri-tert-butyldimethylsilyl group, among others.

[0127] [Polyhydroxystyrene resin (B2)] As the polyhydroxystyrene resin (B2), a resin represented by the following general formula (b4) can be used.

[0128] [Chemical formula]

[0129] In the above 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 repeating unit number of the structure in parentheses.

[0130] The above 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, and 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, a neopentyl group, etc. Examples of the cyclic alkyl group include a cyclopentyl group, a cyclohexyl group, etc.

[0131] As the acid-dissociable dissolution-inhibiting group represented by the above R 9b , the same acid-dissociable dissolution-inhibiting groups as those exemplified for the above R 1b can be used.

[0132] Furthermore, the polyhydroxystyrene resin (B2) can contain other polymerizable compounds as constituent 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; (meth)acrylic acid alkyl esters such as methyl (meth)acrylate; (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate; dicarboxylic acid diesters such as diethyl maleate; vinyl group-containing aromatic compounds such as styrene and vinyltoluene; 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; amide bond-containing polymerizable compounds such as acrylamide, and the like.

[0133] [Acrylic resin (B3)] As the acrylic resin (B3), resins represented by the following general formulas (b5) to (b10) can be used.

[0134] [Chemical formula]

[0135] [Chemical formula]

[0136] In the above general formulas (b5) to (b7), R 10b ~R 17b each independently represents a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, a fluorine atom, or a linear fluorinated alkyl group having 1 to 6 carbon atoms or a branched fluorinated alkyl group having 3 to 6 carbon atoms, and X bforms a hydrocarbon ring having 5 to 20 carbon atoms together with the carbon atom to which it is bonded, and 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.

[0137] 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. In general formula (b8), each R 19b independently represents a hydrogen atom, a hydroxyl group, a cyano group or a COOR 23b group (provided that R 23b represents a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group having 3 to 4 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms). In general formula (b10), each R 22b independently represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms 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 a derivative thereof, or any two R 22b 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 represents 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.

[0138] Among the above component (B), it is preferable to use an acrylic resin (B3).

[0139] Further, the polystyrene-reduced weight average molecular weight of component (B) is preferably from 10,000 to 600,000, more preferably from 50,000 to 600,000, and still more preferably from 230,000 to 550,000. By setting the weight average molecular weight to such a value, the resin physical properties of the resist become excellent.

[0140] Furthermore, component (B) is preferably a resin having a dispersity of 1.05 or more. Here, the "dispersity" means the value obtained by dividing the weight average molecular weight by the number average molecular weight. By setting the dispersity to such a value, the plating resistance and resin physical properties of the resist become excellent.

[0141] The content of the above component (B) is preferably 5 to 60% by weight in the solid content of the chemically amplified positive photoresist composition.

[0142] <Alkali-soluble resin (C)> In the chemically amplified positive photoresist composition of the present invention, in order to improve the resin physical properties of the resist, it is preferable to further contain an alkali-soluble resin (hereinafter referred to as "component (C)" in this specification). As component (C), it is preferably at least one selected from the group consisting of novolak resins, polyhydroxystyrene resins, acrylic resins, and polyvinyl resins.

[0143] The content of the above component (C) is preferably 5 to 95 parts by weight, more preferably 10 to 90 parts by weight, based on 100 parts by weight of the above component (B). By setting it to 5 parts by weight or more, the resin physical properties of the resist can be improved, and by setting it to 95 parts by weight or less, there is a tendency to prevent film loss during development.

[0144] <Acid diffusion control agent (D)> In the chemically amplified positive photoresist composition of the present invention, in order to improve the resist pattern shape, standing stability, etc., it is preferable to further contain an acid diffusion control agent (D) (referred to as "component (D)" in this specification). As the component (D), a nitrogen-containing compound is preferable, and if necessary, an organic carboxylic acid, an oxo acid of phosphorus, or a derivative thereof can be further contained.

[0145] In addition, in the chemically amplified positive photoresist composition of the present invention, an adhesion aid can be further contained in order to improve the adhesion to the substrate. As the adhesion aid to be used, a functional silane coupling agent is preferable.

[0146] In addition, in the chemically amplified positive photoresist composition of the present invention, a surfactant can be further contained in order to improve coatability, defoaming property, leveling property, etc.

[0147] In addition, in the chemically amplified positive photoresist composition of the present invention, an acid, an acid anhydride, or a high-boiling solvent can be further contained in order to finely adjust the solubility in an alkaline developer.

[0148] In addition, although the chemically amplified positive photoresist composition of the present invention basically does not require a sensitizer, a sensitizer can be contained as needed to complement the sensitivity. As such a sensitizer, conventionally known ones can be used, and specifically, the above-mentioned ones can be mentioned.

[0149] 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 sulfonium salt represented by the above general formula (1).

[0150] 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 are the above-mentioned ones.

[0151] The amount of these organic solvents used is preferably in the range where the solid content concentration is 30% by weight or more so that the film thickness of the photoresist layer obtained by using the chemically amplified positive photoresist composition of the present invention (for example, by the spin coating method) is 5 μm or more.

[0152] The preparation of the chemically amplified positive photoresist composition of the present invention may be carried out, for example, by simply mixing and stirring the above components in a usual manner. If necessary, they may be dispersed and mixed using a disperser such as a dissolver, a homogenizer, or a three-roll mill. Further, after mixing, filtration may be carried out using a mesh, a membrane filter, or the like.

[0153] The chemically amplified positive photoresist composition of the present invention is suitable for forming a photoresist layer having a film thickness of usually 5 to 150 μm, more preferably 10 to 120 μm, and still more preferably 10 to 100 μm on a support. This photoresist laminate has a photoresist layer composed of the chemically amplified positive photoresist composition of the present invention laminated on the support.

[0154] The support is not particularly limited, and conventionally known ones can be used. For example, substrates for electronic components and those having a predetermined wiring pattern formed thereon can be exemplified. Examples of such substrates include metal substrates such as silicon, silicon nitride, titanium, tantalum, palladium, titanium tungsten, copper, chromium, iron, and aluminum, and glass substrates. In particular, the chemically amplified positive photoresist composition of the present invention can form a resist pattern well even on a copper substrate. Examples of the material for the wiring pattern include copper, solder, chromium, aluminum, nickel, and gold.

[0155] The above photoresist laminate can be manufactured, for example, as follows. That is, a solution of the chemically amplified positive photoresist composition prepared as described above is applied onto a support, and a desired coating film is formed by removing the solvent by heating. As the method for applying onto the support, methods such as spin coating method, slit coating method, roll coating method, screen printing method, and applicator method can be adopted. The pre-bake conditions of the coating film of the composition of the present invention vary depending on the type, blending ratio, coating film thickness, etc. of each component in the composition, but usually it may be at 70 to 150 °C, preferably 80 to 140 °C, for about 2 to 60 minutes.

[0156] The film thickness of the photoresist layer is usually in the range of 5 to 150 μm, preferably 10 to 120 μm, more preferably 10 to 100 μm.

[0157] To form a resist pattern using the photoresist laminate thus obtained, the obtained photoresist layer may be selectively irradiated (exposed) with light or radiation, for example, ultraviolet light or visible light having a wavelength of 300 to 500 nm, through a mask having a predetermined pattern.

[0158] Here, the "light" may be light that activates the photoacid generator to generate an acid, including ultraviolet light, visible light, and far ultraviolet light, and the "radiation" means X-rays, electron beams, ion beams, etc. As the light source or radiation source, a low-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, metal halide lamp, argon gas laser, LED lamp, etc. can be used. Also, the radiation exposure dose varies depending on the type, blending amount, coating film thickness, etc. of each component in the composition. For example, in the case of using an ultra-high-pressure mercury lamp, it is 50 to 10,000 mJ / cm 2 is.

[0159] Then, after exposure, heating is performed using a known method to promote the diffusion of the acid and change the alkali solubility of the photoresist layer in the exposed portion. Next, for example, a predetermined alkaline aqueous solution is used as a developer to dissolve and remove the unnecessary portions to obtain a predetermined resist pattern.

[0160] The development time varies depending on the type of each component of the composition, the mixing ratio, and the dry film thickness of the composition, but is usually 1 to 30 minutes. Also, the development method may be any of the liquid puddle method, dipping method, paddle method, spray development method, etc. After development, running water washing is performed for 30 to 90 seconds, and drying is carried out using an air gun, an oven, or the like.

[0161] In the non-resist portion (the portion removed by the alkaline developer) of the resist pattern thus obtained, conductive materials such as metals can be embedded by, for example, plating, etc., to form connection terminals such as metal posts and bumps. The plating treatment method is not particularly limited, and various conventionally known methods can be adopted. As the plating solution, solder plating, copper plating, gold plating, and nickel plating solutions are preferably used. The remaining resist pattern is finally removed using a stripping solution or the like according to a conventional method.

[0162] The chemically amplified positive photoresist composition of the present invention can also be used as a dry film. This dry film has protective films formed on both sides of a layer made of the chemically amplified positive photoresist composition of the present invention. The film thickness of the layer made of the chemically amplified positive photoresist composition is usually in the range of 10 to 150 μm, preferably 20 to 120 μm, and more preferably 20 to 80 μm. Also, the protective film is not particularly limited, and a resin film conventionally used for dry films can be used. As an example, one side can be a polyethylene terephthalate film, and the other side can be one selected from the group consisting of a polyethylene terephthalate film, a polypropylene film, and a polyethylene film.

[0163] The chemically amplified positive dry film as described above can be manufactured, for example, as follows. That is, a solution of the chemically amplified positive photoresist composition prepared as described above is applied onto one protective film, and a desired coating film is formed by removing the solvent by heating. The drying conditions vary depending on the type of each component in the composition, the blending ratio, the coating film thickness, etc., but usually it may be at 60 to 100 °C for about 5 to 20 minutes.

[0164] In order to form a resist pattern using the chemically amplified dry film thus obtained, one protective film of the chemically amplified positive dry film is peeled off, and it is laminated onto the support with the exposed surface facing the support side as described above to obtain a photoresist layer. Then, after pre-baking to dry the resist, the other protective film may be peeled off.

[0165] For the photoresist layer thus obtained on the support, a resist pattern can be formed in the same manner as described above for the photoresist layer formed by directly applying it onto the support.

[0166] The chemically amplified negative photoresist composition of the present invention is characterized by containing a component (E) comprising a photoacid generator of the present invention which is a compound that generates an acid upon irradiation with light or radiation, an alkali-soluble resin (F) having a phenolic hydroxyl group, and a crosslinking agent (G).

[0167] Alkali-soluble resin (F) having a phenolic hydroxyl group The "alkali-soluble resin having a phenolic hydroxyl group" in the present invention (hereinafter referred to as "phenolic resin (F)") includes, for example, novolak resin, polyhydroxystyrene, copolymer of polyhydroxystyrene, copolymer of 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, etc. Among these, novolak resin, polyhydroxystyrene, copolymer of polyhydroxystyrene, copolymer of hydroxystyrene and styrene, copolymer of hydroxystyrene, styrene and (meth)acrylic acid derivative, phenol-xylylene glycol condensation resin are preferable. Incidentally, these phenolic resins (F) may be used alone or in combination of two or more.

[0168] In addition, the above phenolic resin (F) may contain a phenolic low-molecular compound as a part of the components. Examples of the above phenolic low-molecular compound include 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, etc.

[0169] Crosslinking agent (G) The "crosslinking agent" in the present invention (hereinafter also referred to as "crosslinking agent (G)") is not particularly limited as long as it acts as a crosslinking component (curing component) that reacts with the above phenolic resin (F). Examples of the above crosslinking agent (G) include a compound having at least two or more alkyl-etherified amino groups in the molecule, a compound having a benzene skeleton with at least two or more alkyl-etherified groups in the molecule, an oxirane ring-containing compound, a thiirane ring-containing compound, an oxetanyl group-containing compound, an isocyanate group-containing compound (including blocked ones), etc.

[0170] Among these crosslinking agents (G), compounds having at least two or more alkyl-etherified amino groups in the molecule and oxirane ring-containing compounds are preferred. More preferably, a compound having at least two or more alkyl-etherified amino groups in the molecule and an oxirane ring-containing compound are used in combination.

[0171] 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, based on 100 parts by weight of the phenolic resin (F). When the blending amount of this crosslinking agent (G) is 1 to 100 parts by weight, the curing reaction proceeds sufficiently, and the obtained cured product has a good pattern shape with high resolution and is excellent in heat resistance and electrical insulation, which is preferable. Also, when a compound having an alkyl-etherified amino group and an oxirane ring-containing compound are used in combination, the content ratio of the oxirane ring-containing compound is preferably 50% by weight or less, more preferably 5 to 40% by weight, particularly preferably 5 to 30% by weight, when the total of the compound having an alkyl-etherified amino group and the oxirane ring-containing compound is 100% by weight. In this case, the obtained cured film is preferable because it is excellent in chemical resistance without impairing high resolution.

[0172] Crosslinked fine particles (H) In the chemically amplified negative photoresist composition of the present invention, crosslinked fine particles (hereinafter, also referred to as "crosslinked fine particles (H)") can be further contained in order to improve the durability and thermal shock resistance of the obtained cured product.

[0173] 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 synthesizing crosslinked fine particles by emulsion polymerization, the number of micelles during emulsion polymerization can be controlled by the amount of emulsifier used, and the particle size can be controlled. The average particle size of the crosslinked fine particles (H) is a value measured by diluting a dispersion of the crosslinked fine particles according to a conventional method using a light scattering flow distribution measuring device or the like.

[0174] The compounding amount of the crosslinked fine particles (H) is preferably 0.5 to 50 parts by weight, more preferably 1 to 30 parts by weight, based on 100 parts by weight of the phenolic resin (F). When the compounding 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 obtained cured film can be improved.

[0175] Adhesion promoter In addition, the chemically amplified negative photoresist composition of the present invention may contain an adhesion promoter in order to improve the adhesion to a substrate. Examples of the adhesion promoter include functional silane coupling agents having reactive substituents such as carboxyl group, methacryloyl group, isocyanate group, epoxy group, etc.

[0176] The compounding amount of the adhesion promoter is preferably 0.2 to 10 parts by weight, more preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the phenolic resin (F). When the compounding amount of the adhesion promoter is 0.2 to 10 parts by weight, it is preferable because it has excellent storage stability and can obtain good adhesion.

[0177] Solvent In addition, the chemically amplified negative photoresist composition of the present invention may contain a solvent in order to improve the handleability of the resin composition or to adjust the viscosity and storage stability. The solvent is not particularly limited, and specific examples include those described above.

[0178] In addition, the chemically amplified negative photoresist composition of the present invention may contain a sensitizer, if necessary. As such a sensitizer, conventionally known ones can be used, and specifically, those described above can be mentioned.

[0179] 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 sulfonium salt represented by the above general formula (1).

[0180] In addition, other additives can be contained in the chemically amplified negative photoresist composition of the present invention to the extent that the properties of the present invention are not impaired, if necessary. Examples of such other additives include inorganic fillers, quenchers, leveling agents, surfactants, and the like.

[0181] The method for preparing the chemically amplified negative photoresist composition of the present invention is not particularly limited, and it can be prepared by a known method. It can also be prepared by stirring a sample bottle filled with each component and completely sealed on a rotary shaker.

[0182] The cured product in the present invention is characterized in that the chemically amplified negative photoresist composition is cured. The chemically amplified negative photoresist composition according to the present invention described above has a high residual film ratio and excellent resolution, and its cured product is excellent in electrical insulation, thermal shock resistance, etc. Therefore, the cured product can be suitably used as a surface protection film, a planarization film, an interlayer insulating film material, etc. for electronic components such as semiconductor elements and semiconductor packages.

[0183] To form the cured product of the present invention, first, the chemically amplified negative photoresist composition according to the present invention described above is applied to a support (copper foil with resin, copper-clad laminate, silicon wafer with metal sputter film, alumina substrate, etc.), dried to volatilize solvents and the like to form a coating film. Then, it is exposed through a desired mask pattern, and heat treatment (hereinafter, this heat treatment is referred to as "PEB") is performed to promote the reaction between the phenolic resin (F) and the crosslinking agent (G). Next, development is carried out with an alkaline developer to dissolve and remove the unexposed portions, whereby a desired pattern can be obtained. Further, a cured film can be obtained by performing heat treatment to develop the insulating film properties.

[0184] As a method of coating the resin composition on a support, for example, coating methods such as dipping method, spraying method, bar coating method, roll coating method, or spin coating method can be used. Also, the thickness of the coating film can be appropriately controlled by adjusting the coating means, the solid content concentration, and the viscosity of the composition solution. Examples of the 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, ghi-line steppers, etc., electron beams, laser beams, and the like. The exposure amount is appropriately selected depending on the light source used, the resin film thickness, etc. For example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, when the resin film thickness is 1 to 50 μm, it is about 100 to 50000 J / m 2 degree.

[0185] After exposure, the above-mentioned PEB treatment is performed to accelerate the curing reaction between the phenolic resin (F) and the crosslinking agent (G) by the generated acid. The PEB conditions vary depending on the blending amount of the resin composition, the film thickness used, etc., but are usually 70 to 150 °C, preferably 80 to 120 °C, for about 1 to 60 minutes. Then, development is carried out with an alkaline developer to dissolve and remove the unexposed portions, thereby forming a desired pattern. Examples of the development method in this case include shower development method, spray development method, immersion development method, paddle development method, and the like. The development conditions are usually about 1 to 10 minutes at 20 to 40 °C.

[0186] Furthermore, in order to sufficiently exhibit the characteristics as an insulating film after development, heat treatment can be performed to sufficiently cure it. Such curing conditions are not particularly limited, but depending on the use of the cured product, it can be cured by heating at a temperature of 50 to 250 °C for about 30 minutes to 10 hours. Also, in order to sufficiently progress the curing or prevent deformation of the obtained pattern shape, heating can be performed in two steps. For example, in the first step, it can be heated at a temperature of 50 to 120 °C for about 5 minutes to 2 hours, and then further heated at a temperature of 80 to 250 °C for about 10 minutes to 10 hours to cure it. With such curing conditions, general ovens, infrared furnaces, etc. can be used as the heating equipment.

Example

[0187] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In addition, parts in each example represent parts by weight.

[0188] (Production Example 1) Synthesis of 4-[(2-tert-butylphenyl)thio]biphenyl 3.0 parts of 4-bromo-biphenyl, 1.9 parts of 2-tert-butylthiophenol, 1.2 parts of potassium hydroxide (purity 85%) and 7.0 parts of N-methylpyrrolidone were mixed and stirred at 120 °C for 1 hour to dissolve uniformly. Then, the reaction was carried out at 180 °C for 5 hours. After the reaction solution was cooled to room temperature (about 25 °C), 7.0 parts of dichloromethane was added and dissolved, and it was washed with 6.5 parts of ion-exchanged water until the pH became neutral. The dichloromethane layer was transferred to a rotary evaporator to distill off the solvent, and then 20 parts of isopropanol was added and heated to 70 °C to dissolve uniformly. Then, crystals were precipitated by cooling to room temperature. The crystals were filtered off to obtain 4-[(2-tert-butylphenyl)thio]biphenyl in a yield of 80%. The product was 1 identified by 1H-NMR.

[0189] (Production Example 2) Synthesis of 4-[(2-tert-butylphenyl)thio]benzophenone 4-[(2-tert-butylphenyl)thio]benzophenone was obtained in a yield of 84% in the same manner as in Production Example 1, except that "3.0 parts of 4-bromo-biphenyl" was changed to "3.0 parts of 4-bromobenzophenone" in Production Example 1. The product was 1 identified by 1H-NMR.

[0190] (Production Example 3) Synthesis of 4-[(2-tert-butoxyphenyl)thio]benzophenone In Production Example 2, 4-[(2-tert-butoxyphenyl)thio]benzophenone was obtained in a yield of 65% in the same manner as in Production Example 2, except that "1.9 parts of 2-tert-butylthiophenol" was changed to "2.2 parts of 2-tert-butoxythiophenol". The product was 1 identified by 1H-NMR.

[0191] (Production Example 4) Synthesis of 4-[(2-trimethylsiloxyphenyl)thio]benzophenone In Production Example 2, 4-[(2-trimethylsiloxyphenyl)thio]benzophenone was obtained in a yield of 70% in the same manner as in Production Example 2, except that "1.9 parts of 2-tert-butylthiophenol" was changed to "2.7 parts of 2-trimethylsiloxythiophenol" and "1.2 parts of potassium hydroxide (85% pure content)" was changed to "1.5 parts of potassium hydroxide (85% pure content)". The product was 1 identified by 1H-NMR.

[0192] (Production Example 5) Synthesis of 4-[(5-tert-butyl-2-methylphenyl)thio]benzophenone In Production Example 2, 4-[(5-tert-butyl-2-methylphenyl)thio]benzophenone was obtained in a yield of 87% in the same manner as in Production Example 2, except that "1.9 parts of 2-tert-butylthiophenol" was changed to "2.7 parts of 5-tert-butyl-2-methylthiophenol". The product was 1 identified by 1H-NMR.

[0193] (Production Example 6) Synthesis of 2-[(5-tert-butyl-2-methylphenyl)thio]anthraquinone In Production Example 5, 2-[(5-tert-butyl-2-methylphenyl)thio]anthraquinone was obtained in a yield of 68% in the same manner as in Production Example 5, except that "3.0 parts of 4-bromobenzophenone" was changed to "3.1 parts of 2-chloroanthraquinone". The product was 1 identified by 1H-NMR.

[0194] (Production Example 7) Synthesis of 4-[(5-tert-butyl-2-methylphenyl)thio]phenyl phenyl sulfone In Production Example 5, 4-[(5-tert-butyl-2-methylphenyl)thio]phenyl phenyl sulfone was obtained in a yield of 70% in the same manner as in Production Example 5, except that “3.0 parts of 4-bromobenzophenone” was changed to “3.0 parts of 4-bromophenyl phenyl sulfone”. The product was 1 identified by 1H-NMR.

[0195] (Example 1) Synthesis of Compound P1-TF

[0196] [Chemical formula]

[0197] 3.0 parts of 4-[(2-tert-butylphenyl)thio]biphenyl synthesized in Production Example 1, 10 parts of acetonitrile, 0.04 part of sulfuric acid and 0.40 part of 35% aqueous hydrogen peroxide solution were uniformly mixed and reacted at 65 °C for 3 hours. The reaction solution was transferred to a rotary evaporator to distill off the solvent, thereby obtaining a mixture containing 48% of 4-[(2-tert-butylphenyl)sulfinyl]biphenyl and 52% of 4-[(2-tert-butylphenyl)thio]biphenyl. The content was calculated from the peak area ratio by HPLC analysis of the mixture. This mixture was dissolved in 15 parts of dichloromethane, and 1.6 parts of trifluoromethanesulfonic anhydride was added dropwise. The mixture was stirred at room temperature for 1 hour, and the reaction solution was washed with 15 parts of water. This washing operation was repeated until the pH became neutral. Thereafter, 15 parts of hexane was added to the organic layer, and after stirring, the operation of standing for 30 minutes and then removing the upper layer was performed twice to remove unreacted raw materials. The lower layer was transferred to a rotary evaporator to distill off the solvent, thereby obtaining Compound P1-TF in a yield of 55%. The product was 1 identified by 1H-NMR, 19 19F-NMR and LC-MS.

[0198] (Example 2) Synthesis of Compound P1-SB

[0199] [Chemical formula]

[0200] 1.0 part of P1-TF synthesized in Example 1 was dissolved in 5.8 parts of dichloromethane, and 0.40 part of potassium hexafluoroantimonate and 5.1 parts of ion-exchanged water were added thereto, followed by stirring at room temperature for 1 hour. The organic layer was washed 5 times with 5 parts of ion-exchanged water, and then transferred to a rotary evaporator to distill off the solvent, thereby obtaining P1-SB in a yield of 95%. The product was 1 identified by 1H-NMR 19 and 19F-NMR.

[0201] (Example 3) Synthesis of Compound P1-FP

[0202] [Chemical formula]

[0203] Compound P1-FP was obtained in a yield of 94% in the same manner as in Example 2, except that "0.40 part of potassium hexafluoroantimonate" was changed to "0.65 part of potassium tris(pentafluoroethyl)trifluorophosphate".

[0204] (Example 4) Synthesis of Compound P1-B

[0205] [Chemical formula]

[0206] Compound P1-B was obtained in a yield of 95% in the same manner as in Example 2, except that "0.40 part of potassium hexafluoroantimonate" was changed to "0.90 part of sodium tetrakis(pentafluorophenyl)borate".

[0207] (Example 5) Synthesis of Compound P1-GA

[0208] [Chemical formula]

[0209] In Example 2, Compound P1-GA was obtained in a yield of 95% in the same manner as in Example 2, except that "0.40 part of potassium hexafluoroantimonate" was changed to "0.95 part of sodium tetrakis(pentafluorophenyl)gallate".

[0210] (Example 6) Synthesis of Compound P2-FP

[0211] [Chemical formula]

[0212] 3.0 parts of 4-[(2-tert-butylphenyl)thio]benzophenone synthesized in Production Example 2, 10 parts of acetonitrile, 0.04 part of sulfuric acid, and 0.40 part of 35% aqueous hydrogen peroxide solution were uniformly mixed and reacted at 65 °C for 3 hours. The reaction solution was transferred to a rotary evaporator to distill off the solvent, thereby obtaining a mixture containing 48% of 4-[(2-tert-butylphenyl)sulfinyl]benzophenone and 52% of 4-[(2-tert-butylphenyl)thio]benzophenone. The content was calculated from the peak area ratio by HPLC analysis of the mixture. This mixture was dissolved in 15 parts of dichloromethane, and 1.6 parts of trifluoromethanesulfonic anhydride was added dropwise. The mixture was stirred at room temperature for 1 hour, and the reaction solution was washed with 15 parts of water. This washing operation was repeated until the pH became neutral. Then, 2.0 parts of potassium tris(pentafluoroethyl)trifluorophosphate and 15 parts of water were added, and the mixture was stirred at room temperature for 1 hour. The operation of washing the organic layer with 15 parts of water was repeated 3 times. Thereafter, 15 parts of hexane was added to the organic layer, and after stirring, the operation of removing the upper layer after standing for 30 minutes was performed twice to remove unreacted raw materials. The lower layer was transferred to a rotary evaporator to distill off the solvent, thereby obtaining Compound P2-FP in a yield of 65%. The product was 1 identified by 1H-NMR, 19 19F-NMR, and LC-MS.

[0213] (Example 7) Synthesis of Compound P3-FP

[0214] [Chemical formula]

[0215] 2.9 parts of 4-[(2-tert-butoxyphenyl)thio]benzophenone synthesized in Production Example 3, 10 parts of acetonitrile, 0.04 part of sulfuric acid, and 0.39 part of 35% aqueous hydrogen peroxide solution were uniformly mixed and reacted at 65°C for 3 hours. The reaction solution was transferred to a rotary evaporator to distill off the solvent, thereby obtaining a mixture containing 47% of 4-[(2-tert-butoxyphenyl)sulfinyl]benzophenone and 53% of 4-[(2-tert-butoxyphenyl)thio]benzophenone. The content was calculated from the peak area ratio by HPLC analysis of the mixture. This mixture was dissolved in 15 parts of dichloromethane, and 1.6 parts of trifluoromethanesulfonic anhydride was added dropwise. The mixture was stirred at room temperature for 1 hour, and the reaction solution was washed with 15 parts of water. This washing operation was repeated until the pH became neutral. Then, 2.0 parts of potassium tris(pentafluoroethyl)trifluorophosphate and 15 parts of water were added, and the mixture was stirred at room temperature for 1 hour. The operation of washing the organic layer with 15 parts of water was repeated 3 times. Thereafter, 15 parts of hexane was added to the organic layer, and after stirring, the operation of standing for 30 minutes and then removing the upper layer was performed 2 times to remove unreacted raw materials. The lower layer was transferred to a rotary evaporator to distill off the solvent, and the residue was isolated and purified by column chromatography (eluent: ethyl acetate / hexane = 3 / 1: volume ratio) to obtain Compound P3-FP in a yield of 35%. The product was 1 identified by 1H-NMR, 19 19F-NMR and LC-MS.

[0216] (Example 8) Synthesis of Compound P4-FP

[0217] [Chemical formula]

[0218] 2.9 parts of 4-[(2-trimethylsiloxyphenyl)thio]benzophenone synthesized in Production Example 4, 10 parts of acetonitrile, 0.04 part of sulfuric acid, and 0.38 part of a 35% aqueous hydrogen peroxide solution were uniformly mixed and reacted at 65 °C for 3 hours. The reaction solution was transferred to a rotary evaporator to distill off the solvent, thereby obtaining a mixture containing 47% of 4-[(2-trimethylsiloxyphenyl)sulfinyl]benzophenone and 53% of 4-[(2-trimethylsiloxyphenyl)thio]benzophenone. The content was calculated from the peak area ratio by HPLC analysis of the mixture. This mixture was dissolved in 15 parts of dichloromethane, and 1.6 parts of trifluoromethanesulfonic anhydride was added dropwise. The mixture was stirred at room temperature for 1 hour, and the reaction solution was washed with 15 parts of water. This washing operation was repeated until the pH became neutral. Then, 2.0 parts of potassium tris(pentafluoroethyl)trifluorophosphate and 15 parts of water were added, and the mixture was stirred at room temperature for 1 hour. The operation of washing the organic layer with 15 parts of water was repeated 3 times. Thereafter, 15 parts of hexane was added to the organic layer, and after stirring, the operation of removing the upper layer after standing for 30 minutes was performed twice to remove unreacted raw materials. The lower layer was transferred to a rotary evaporator to distill off the solvent, and the residue was isolated and purified by column chromatography (eluent: ethyl acetate / hexane = 2.5 / 1: volume ratio), whereby Compound P4-FP was obtained in a yield of 13%. The product was 1 identified by 19 1H-NMR,

[0219] (Example 9) Synthesis of Compound P5-FP

[0220] [Chemical formula]

[0221] 3.0 parts of 4-[(5-tert-butyl-2-methylphenyl)thio]benzophenone synthesized in Production Example 5, 10 parts of acetonitrile, 0.04 part of sulfuric acid and 0.35 part of 35% aqueous hydrogen peroxide solution were uniformly mixed and reacted at 65 °C for 3 hours. The reaction solution was transferred to a rotary evaporator to distill off the solvent, thereby obtaining a mixture containing 48% of 4-[(5-tert-butyl-2-methylphenyl)sulfinyl]benzophenone and 52% of 4-[(5-tert-butyl-2-methylphenyl)thio]benzophenone. The content was calculated from the peak area ratio by HPLC analysis of the mixture. This mixture was dissolved in 15 parts of dichloromethane, and 1.6 parts of trifluoromethanesulfonic anhydride was added dropwise. The mixture was stirred at room temperature for 1 hour, and the reaction solution was washed with 15 parts of water. This washing operation was repeated until the pH became neutral. Then, 2.0 parts of potassium tris(pentafluoroethyl)trifluorophosphate and 15 parts of water were added, and the mixture was stirred at room temperature for 1 hour. The operation of washing the organic layer with 15 parts of water was repeated 3 times. Thereafter, 15 parts of hexane was added to the organic layer, and after stirring, the operation of removing the upper layer after standing for 30 minutes was performed twice to remove unreacted raw materials. The lower layer was transferred to a rotary evaporator to distill off the solvent, thereby obtaining Compound P5-FP in a yield of 47%. The product was 1 identified by 19 1H-NMR,

[0222] (Example 10) Synthesis of Compound P6-FP

[0223] [Chemical formula]

[0224] 1.0 part of the sulfonium salt P5-FP obtained from Example 9, 4.2 parts of acetonitrile, 0.01 part of sulfuric acid, and 0.10 part of 35% hydrogen peroxide solution were uniformly mixed and reacted at 40 °C for 3 hours. The reaction solution was cooled to room temperature, 10 parts of ion-exchanged water was added, and the mixture was extracted with 5 parts of dichloromethane. The aqueous layer was removed, 10 parts of ion-exchanged water was added again, and the organic layer was washed. This washing operation was carried out until the pH became neutral. Then, the organic layer was transferred to a rotary evaporator to distill off the solvent, and the residue was isolated and purified by column chromatography (eluent: ethyl acetate / hexane = 3 / 1: volume ratio) to obtain compound P6-FP in a yield of 80%. The product was 1 1H-NMR, 19 19F-NMR, and LC-MS.

[0225] (Example 11) Synthesis of compound P7-FP

[0226]

Chemical formula

[0227] 1.0 part of the sulfonium salt P5-FP obtained from Example 9, 4.2 parts of acetonitrile, 0.01 part of sulfuric acid, and 0.25 part of 35% hydrogen peroxide solution were uniformly mixed and reacted at 80 °C for 5 hours. The reaction solution was cooled to room temperature, 10 parts of ion-exchanged water was added, and the mixture was extracted with 5 parts of dichloromethane. The aqueous layer was removed, 10 parts of ion-exchanged water was added again, and the organic layer was washed. This washing operation was carried out until the pH became neutral. Then, the organic layer was transferred to a rotary evaporator to distill off the solvent, and the residue was isolated and purified by column chromatography (eluent: ethyl acetate / hexane = 2 / 1: volume ratio) to obtain compound P7-FP in a yield of 37%. The product was 1 1H-NMR, 19 19F-NMR, and LC-MS.

[0228] (Example 12) Synthesis of compound P8-FP

[0229]

Chemical formula

[0230] 3.0 parts of 2-[(5-tert-butyl-2-methylphenyl)thio]anthraquinone synthesized in Production Example 5, 20 parts of acetonitrile, 0.04 part of sulfuric acid and 0.35 part of a 35% aqueous hydrogen peroxide solution were uniformly mixed and reacted at 65 °C for 3 hours. The reaction solution was transferred to a rotary evaporator to distill off the solvent, thereby obtaining a mixture containing 47% of 2-[(5-tert-butyl-2-methylphenyl)sulfinyl]anthraquinone and 53% of 2-[(5-tert-butyl-2-methylphenyl)thio]anthraquinone. The content was calculated from the peak area ratio by HPLC analysis of the mixture. This mixture was dissolved in 15 parts of dichloromethane, and 1.6 parts of trifluoromethanesulfonic anhydride was added dropwise. The mixture was stirred at room temperature for 1 hour, and the reaction solution was washed with 15 parts of water. This washing operation was repeated until the pH became neutral. Then, 2.0 parts of potassium tris(pentafluoroethyl)trifluorophosphate and 15 parts of water were added, and the mixture was stirred at room temperature for 1 hour. The operation of washing the organic layer with 15 parts of water was repeated 3 times. Thereafter, 15 parts of toluene was added to the organic layer, and after stirring, the operation of removing the upper layer after standing for 30 minutes was performed twice to remove unreacted raw materials. The lower layer was transferred to a rotary evaporator to distill off the solvent, 20 parts of acetonitrile, 0.04 part of sulfuric acid, and 0.8 part of 35% hydrogen peroxide water were uniformly mixed, and the mixture was reacted at 80 °C for 7 hours. The reaction solution was cooled to room temperature, 20 parts of ion-exchanged water was added, and extraction was performed with 20 parts of dichloromethane. The aqueous layer was removed, 20 parts of ion-exchanged water was added again, and the organic layer was washed. This washing operation was carried out until the pH became neutral, and then the organic layer was transferred to a rotary evaporator to distill off the solvent, and the residue was isolated and purified by column chromatography (eluent: ethyl acetate / hexane = 4 / 1: volume ratio) to obtain Compound P8-FP in a yield of 32%. The product was 1 identified by 1H-NMR, 19 19F-NMR, and LC-MS.

[0231] (Example 13) Synthesis of Compound P9-FP

[0232] [Chemical]

[0233] 3.0 parts of 4-[(5-tert-butyl-2-methylphenyl)thio]phenyl phenyl sulfone synthesized in Production Example 7, 10 parts of acetonitrile, 0.04 part of sulfuric acid and 0.35 part of 35% aqueous hydrogen peroxide solution were uniformly mixed and reacted at 65 °C for 7 hours. The reaction solution was transferred to a rotary evaporator to distill off the solvent, thereby obtaining a mixture containing 48% of 4-[(5-tert-butyl-2-methylphenyl)sulfinyl]phenyl phenyl sulfone and 52% of 4-[(5-tert-butyl-2-methylphenyl)thio]phenyl phenyl sulfone. The content was calculated from the peak area ratio by HPLC analysis of the mixture. This mixture was dissolved in 15 parts of dichloromethane, and 1.6 parts of trifluoromethanesulfonic anhydride was added dropwise. The mixture was stirred at room temperature for 2 hours, and the reaction solution was washed with 15 parts of water. This washing operation was repeated until the pH became neutral. Then, 2.0 parts of potassium tris(pentafluoroethyl)trifluorophosphate and 15 parts of water were added, and the mixture was stirred at room temperature for 1 hour. The operation of washing the organic layer with 15 parts of water was repeated 4 times. Thereafter, 15 parts of toluene was added to the organic layer, and after stirring, the operation of standing for 30 minutes and then removing the upper layer was performed 4 times to remove unreacted raw materials. The lower layer was transferred to a rotary evaporator to distill off the solvent, thereby obtaining Compound P9-FP in a yield of 59%. The product was 1 identified by 1H-NMR, 19 19F-NMR and LC-MS.

[0234] (Comparative Example 1) Synthesis of Compound H1-TF

[0235] [Chemical]

[0236] 2.0 parts of 4-(phenylthio)biphenyl, 8.0 parts of acetonitrile, 0.03 part of sulfuric acid and 0.32 part of 35% aqueous hydrogen peroxide solution were uniformly mixed and reacted at 65 °C for 3 hours. The reaction solution was transferred to a rotary evaporator to distill off the solvent, and then dissolved in 15 parts of dichloromethane. 1.0 part of trifluoromethanesulfonic anhydride was added dropwise. The mixture was stirred at room temperature for 1 hour, and the reaction solution was washed with 15 parts of water. This washing operation was repeated until the pH became neutral. Thereafter, 15 parts of hexane was added to the organic layer, and after stirring, the operation of removing the upper layer was performed twice after standing for 30 minutes to remove unreacted raw materials. The lower layer was transferred to a rotary evaporator to distill off the solvent, thereby obtaining Compound H1-TF.

[0237] (Comparative Example 2) Synthesis of Compound H1-FP

[0238]

Chemical formula

[0239] 2.0 parts of 4-(phenylthio)biphenyl, 8.0 parts of acetonitrile, 0.03 part of sulfuric acid and 0.32 part of 30% aqueous hydrogen peroxide solution were uniformly mixed and reacted at 65 °C for 2 hours. The reaction solution was transferred to a rotary evaporator to distill off the solvent, and then 6.5 parts of acetonitrile, 1.2 parts of acetic anhydride, 2.0 parts of potassium tris(pentafluoroethyl)trifluorophosphate and 0.7 part of sulfuric acid were uniformly mixed and reacted at 60 °C for 2 hours. The reaction solution was cooled to room temperature, poured into 30 parts of water, extracted with 15 parts of dichloromethane, and washed with water until the pH of the aqueous layer became neutral. Thereafter, 15 parts of hexane was added to the organic layer, and after stirring, the operation of removing the upper layer was performed twice after standing for 30 minutes to remove unreacted raw materials. The lower layer was transferred to a rotary evaporator to distill off the solvent, thereby obtaining Compound H1-FP.

[0240] (Comparative Example 3) Synthesis of Compound H2-FP

[0241]

Chemical formula

[0242] In Comparative Example 2, Compound H2-FP was obtained in the same manner as in Comparative Example 2, except that "2.0 parts of 4-(phenylthio)biphenyl" was changed to "2.0 parts of 4-(phenylthio)benzophenone".

[0243] (Comparative Example 4) Synthesis of Compound H3-FP

[0244]

Chemical formula

[0245] 1.0 part of Compound H2-FP obtained from Comparative Example 3, 4.2 parts of acetonitrile, 0.01 part of sulfuric acid, and 0.11 part of 35% hydrogen peroxide solution were uniformly mixed and reacted at 40 °C for 3 hours. The reaction solution was cooled to room temperature, 10 parts of ion-exchanged water was added, and the mixture was extracted with 5 parts of dichloromethane. The aqueous layer was removed, 10 parts of ion-exchanged water was added again, and the organic layer was washed. This washing operation was carried out until the pH became neutral, and then the organic layer was transferred to a rotary evaporator to distill off the solvent, and the residue was isolated and purified by column chromatography (eluent: ethyl acetate / hexane = 3 / 1: volume ratio) to obtain Compound H3-FP.

[0246] (Comparative Example 5) Synthesis of Compound H4-FP

[0247]

Chemical formula

[0248] 1.0 part of Compound H2-FP obtained from Comparative Example 3, 4.2 parts of acetonitrile, 0.01 part of sulfuric acid, and 0.27 part of 35% hydrogen peroxide solution were uniformly mixed and reacted at 80 °C for 5 hours. The reaction solution was cooled to room temperature, 10 parts of ion-exchanged water was added, and the mixture was extracted with 5 parts of dichloromethane. The aqueous layer was removed, 10 parts of ion-exchanged water was added again, and the organic layer was washed. This washing operation was carried out until the pH became neutral. Then, the organic layer was transferred to a rotary evaporator to distill off the solvent, and the residue was isolated and purified by column chromatography (eluent: ethyl acetate / hexane = 2 / 1: volume ratio) to obtain Compound H4-FP.

[0249] (Comparative Example 6) Synthesis of Compound H5-FP

[0250] [Chemical formula]

[0251] 2.9 parts of 2-(phenylthio)anthraquinone, 20 parts of acetonitrile, 0.04 part of sulfuric acid, and 0.35 part of 35% aqueous hydrogen peroxide solution were uniformly mixed and reacted at 65 °C for 3 hours. The reaction solution was transferred to a rotary evaporator to distill off the solvent, and a mixture containing 47% of 2-(phenylsulfinyl)anthraquinone and 53% of 2-(phenylthio)anthraquinone was obtained. The content was calculated from the peak area ratio by HPLC analysis of the mixture. This mixture was dissolved in 15 parts of dichloromethane, and 1.6 parts of trifluoromethanesulfonic anhydride was added dropwise. The mixture was stirred at room temperature for 1 hour, and the reaction solution was washed with 15 parts of water. This washing operation was repeated until the pH became neutral. Then, 2.0 parts of potassium tris(pentafluoroethyl)trifluorophosphate and 15 parts of water were added, and the mixture was stirred at room temperature for 1 hour. The operation of washing the organic layer with 15 parts of water was repeated 3 times. Then, 15 parts of toluene was added to the organic layer, and after stirring, the operation of removing the upper layer after standing for 30 minutes was carried out 2 times to remove the unreacted raw materials. The lower layer was transferred to a rotary evaporator to distill off the solvent. 20 parts of acetonitrile, 0.04 part of sulfuric acid, and 0.8 part of 35% hydrogen peroxide solution were uniformly mixed and reacted at 80 °C for 7 hours. The reaction solution was cooled to room temperature, 20 parts of ion-exchanged water was added, and the mixture was extracted with 20 parts of dichloromethane. The aqueous layer was removed, 20 parts of ion-exchanged water was added again, and the organic layer was washed. This washing operation was carried out until the pH became neutral, and then the organic layer was transferred to a rotary evaporator to distill off the solvent, thereby obtaining compound H5-FP.

[0252] (Comparative Example 7) Synthesis of Compound H6-FP

[0253] [Chemical Formula]

[0254] 2.0 parts of 4-[(phenylthio)phenyl]phenyl sulfone, 8.0 parts of acetonitrile, 0.03 part of sulfuric acid, and 0.32 part of 30% aqueous hydrogen peroxide solution were uniformly mixed and reacted at 65 °C for 7 hours. After the reaction solution was transferred to a rotary evaporator to distill off the solvent, 6.5 parts of acetonitrile, 1.2 parts of acetic anhydride, 2.0 parts of potassium tris(pentafluoroethyl)trifluorophosphate, and 0.7 part of sulfuric acid were uniformly mixed and reacted at 60 °C for 6 hours. The reaction solution was cooled to room temperature, poured into 30 parts of water, extracted with 15 parts of dichloromethane, and washed with water until the pH of the aqueous layer became neutral. Then, 15 parts of toluene was added to the organic layer, stirred, allowed to stand for 30 minutes, and the operation of removing the upper layer was carried out 4 times to remove unreacted raw materials. The lower layer was transferred to a rotary evaporator to distill off the solvent, thereby obtaining compound H6-FP.

[0255] [Evaluation of the Light Absorption Characteristics of Sulfonium Salts] Solutions (Examples A1 to A13, Comparative Examples HA1 to HA7) were prepared by dissolving and diluting the photoacid generator (sulfonium salt) of the present invention and the photoacid generator (sulfonium salt) of the comparative example to 0.25 mmol / L with acetonitrile. Using an ultraviolet-visible spectrophotometer (UV-2550, manufactured by Shimadzu Corporation), the absorbance at a cell length of 1 cm was measured in the range of 200 nm to 500 nm for this solution. The molar extinction coefficient (ε 365 ) at the i-line (365 nm) was calculated from the following formula, and the results are shown in Table 1. ε 365 (L·mol -1 ·cm -1 ) = A 365 / (0.00025 mol / L × 1 cm) [In the formula, A 365 represents the absorbance at 365 nm.]

[0256]

Table 1

[0257] 〔Preparation and Evaluation of Energy Ray-Curable Composition〕 <Adjustment of Curable Composition> The photoacid generator (sulfonium salt) of the present invention and the photoacid generator (sulfonium salt) of the comparative example were dissolved in Solvent-1 (propylene carbonate) in the blending amounts shown in Table 2, and then uniformly mixed with an epoxide, which is a cationic polymerizable compound (described below), in the blending amounts (parts by weight) shown in Table 2 to prepare energy ray-curable compositions (Examples C1 to C15, Comparative Examples HC1 to HC9). <Epoxy Resin> EP-1: 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate EP-2: 2,2-Bis(4-glycidyloxyphenyl)propane EP-3: 3-Ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane

[0258]

Table 2

[0259] Note that the sulfonium salts obtained in Example 1 and Comparative Example 1 are trifluoromethanesulfonates, and the hexafluoroantimonates, tris(pentafluoroethyl) trifluorophosphates, tetrakis(pentafluorophenyl) borates, and tetrakis(pentafluorophenyl) gallium salts obtained in Examples 2 to 13 and Comparative Examples 2 to 7 have a weaker acid strength and lower activity for cationic polymerization. Therefore, the amount of the sulfonium salt was increased so that it could be evaluated under the same conditions. Accordingly, the amount of Solvent-1 was also increased. Also, as can be seen from the results in Table 1, the sulfonium salts obtained in Example 12 and Comparative Example 6 have a large molar extinction coefficient. Therefore, the amount of the sulfonium salt was decreased so that it could be evaluated under the same conditions. Accordingly, the amount of Solvent-1 was also decreased.

[0260] <Photosensitivity (Photocurability) Evaluation> The energy ray curable composition obtained above was applied to a polyethylene terephthalate (PET) film using an applicator (40 μm). The PET film was irradiated with ultraviolet light whose wavelength was limited by a filter using an ultraviolet irradiation device. Note that an L-34 filter (manufactured by Kenko Optics Co., Ltd., a filter that cuts light of 340 nm or less) was used as the filter. After irradiation, the coating film hardness after 40 minutes was measured by pencil hardness (JIS K5600-5-4:1999) and evaluated according to the following criteria (the coating film thickness after curing was about 40 μm). These results are shown in Table 3. The higher the pencil hardness, the better the photocurability of the energy ray curable composition, that is, the better the polymerization initiation ability of the sulfonium salt for the cationic polymerizable compound (photosensitivity of the sulfonium salt).

[0261] (Evaluation Criteria) ◎: Pencil hardness is H or higher ○: Pencil hardness is HB to B △: Pencil hardness is 2B to 4B ×: Liquid to tacky, unable to measure pencil hardness

[0262] (Irradiation Conditions of Ultraviolet Light) · UV irradiation device: Belt conveyor type UV irradiation device (manufactured by Eye Graphics Co., Ltd.) · Lamp: 1.5 kW high-pressure mercury lamp · Filter: L-34 (manufactured by Kenko Optics Co., Ltd.) · Illuminance (measured with a 365 nm head illuminance meter): 100 mW / cm 2

[0263] · Integrated light quantity (measured with a 365 nm head illuminance meter): Condition-1: 100 mJ / cm 2 Condition-2: 200 mJ / cm 2 Condition-3: 300 mJ / cm 2

[0264]

Table 3

[0265] In the results of Table 1 and Table 3, from the comparison between Examples C1 to C5 and Comparative Examples HC1 to HC2 of the photoacid generator (sulfonium salt), Examples C6 to C11 and Comparative Examples HC3 to HC5, Example C12 and Comparative Example HC6, Example C13 and Comparative Example HC7, Example C14 and Comparative Example HC8, and Example C15 and Comparative Example HC9, although the light absorption of the photoacid generator of the present invention does not increase significantly compared to the comparative photoacid generator, due to having the substituent A1 or A2 in the general formula (1), the curing performance (photosensitivity) of the cationic polymerizable compound is excellent.

[0266] 〔Evaluation of chemically amplified positive photoresist composition〕 <Preparation of evaluation sample> As shown in Table 4, 1 part by weight of component (A) which is a photoacid generator, 40 parts by weight of a resin represented by the following chemical formula (Resin-1) as a resin component (B), and 60 parts by weight of a novolak resin obtained by addition condensation of m-cresol and p-cresol in the presence of formaldehyde and an acid catalyst as a resin component (C) were uniformly dissolved in Solvent-2 (propylene glycol monomethyl ether acetate), filtered through a membrane filter with a pore size of 1 μm, and a chemically amplified positive photoresist composition (Examples P1 to P13) with a solid content concentration of 40% by weight was prepared. Also, comparative examples were carried out in the same manner with the compounding amounts shown in Table 4, and chemically amplified positive photoresist compositions (Comparative Examples HP1 to HP7) were prepared.

[0267]

Table 4

[0268]

Chem.

[0269] <Sensitivity Evaluation> On a silicon wafer substrate, the positive resist compositions prepared in Examples P1 to P13 and Comparative Examples HP1 to HP7 above were spin-coated and then dried to obtain a photoresist layer having a film thickness of about 20 μm. This resist layer was prebaked at 130 °C for 6 minutes using a hot plate. After prebaking, pattern exposure (i-line) was performed using TME-150RSC (manufactured by Topcon Corporation), and post-exposure baking (PEB) was performed at 75 °C for 5 minutes using a hot plate. Then, development treatment was performed for 5 minutes by an immersion method using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide, washed with running water, and blown with nitrogen to obtain a 10 μm line and space (L&S) pattern. Furthermore, the minimum exposure amount at which no residue of this pattern was observed below this, that is, the minimum essential exposure amount required to form a resist pattern (corresponding to sensitivity) was measured. The smaller the essential exposure amount, the better the photoreactivity of the positive resist composition, that is, the better the photosensitivity of the sulfonium salt.

[0270] <Storage stability evaluation> Also, using the chemically amplified positive resist composition prepared above, the photosensitivity (sensitivity) evaluation was carried out as described above immediately after preparation and after storage at 40 °C for 1 month, and the storage stability was judged according to the following criteria. ○: The change in sensitivity after storage at 40 °C for 1 month is less than 5% of the sensitivity immediately after preparation ×: The change in sensitivity after storage at 40 °C for 1 month is 5% or more of the sensitivity immediately after preparation

[0271] <Pattern shape evaluation> By the above operation, the dimension La of the lower side and the dimension Lb of the upper side of the cross-section of the shape 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 5. ◎: 0.90 ≦ Lb / La ≦ 1 ○: 0.85 ≦ Lb / La < 0.90 ×: Lb / La < 0.85

[0272]

Table 5

[0273] In the results of Table 1 and Table 5, comparing Examples P1 to P5 and Comparative Examples HP1 to HP2 of the photoacid generator (sulfonium salt), Examples P6 to P9 and Comparative Example HP3, Example P10 and Comparative Example HP4, Example P11 and Comparative Example HP5, Example P12 and Comparative Example HP6, and Example P13 and Comparative Example HP7, the photoacid generator of the present invention, compared with the comparative photoacid generator, although the light absorption does not increase significantly, by having the substituent A1 or A2 in the general formula (1), it has excellent photosensitivity when used as a chemically amplified positive resist.

[0274] [Evaluation of Chemically Amplified Negative Photoresist Composition] <Preparation of Evaluation Sample> As shown in Table 6, 1 part by weight of component (E) which is a photoacid generator, 100 parts by weight of a copolymer (Mw = 10,000) consisting of p-hydroxystyrene / styrene = 80 / 20 (molar ratio) as component (F) which is a phenolic resin, 20 parts by weight of hexamethoxymethylmelamine (manufactured by Sanwa Chemical Co., Ltd., trade name "Niclac MW-390") as component (G) which is a crosslinking agent, 10 parts by weight of a copolymer consisting of butadiene / acrylonitrile / hydroxybutyl methacrylate / methacrylic acid / divinylbenzene = 64 / 20 / 8 / 6 / 2 (weight%) (average particle diameter = 65 nm, Tg = -38°C) as component (H) which is crosslinking fine particles, 5 parts by weight of γ-glycidoxypropyltrimethoxysilane (manufactured by Chisso Corporation, trade name "S510") as component (I) which is an adhesion promoter were uniformly dissolved in 145 parts by weight of solvent-3 (ethyl lactate) to prepare the chemically amplified negative photoresist composition (Examples N1 to N13) of the present invention. Also, comparative examples were carried out in the same manner with the compounding amounts shown in Table 6 to prepare chemically amplified negative photoresist compositions (Comparative Examples HN1 to HN7).

[0275]

Table 6

[0276] <Sensitivity evaluation> After spin-coating each composition on a silicon wafer substrate, it was heated and dried at 110°C for 3 minutes using a hot plate to obtain a resin coating film having a film thickness of about 20 μm. Then, pattern exposure (i-line) was performed using TME-150RSC (manufactured by Topcon Corporation), and post-exposure baking (PEB) was performed at 110°C for 3 minutes using a hot plate. Then, development treatment was performed for 2 minutes by an immersion method using a 2.38 wt% aqueous solution of tetramethylammonium hydroxide, washed with running water, and blown with nitrogen to obtain a 10-μm line and space pattern. Furthermore, the minimum necessary exposure amount (corresponding to sensitivity) required to form a pattern with a remaining film ratio indicating the ratio of the remaining film before and after development of 95% or more was measured. The smaller the necessary exposure amount, the better the photoreactivity of the negative resist composition, that is, the better the photosensitivity of the sulfonium salt.

[0277] <Storage stability evaluation> In addition, using the chemically amplified negative resist composition prepared above, the photosensitivity (sensitivity) evaluation was performed as described above immediately after preparation and after storage at 40°C for 1 month, and the storage stability was judged according to the following criteria. ○: The sensitivity change after storage at 40°C for 1 month is less than 5% of the sensitivity immediately after preparation ×: The sensitivity change after storage at 40°C for 1 month is 5% or more of the sensitivity immediately after preparation

[0278] <Pattern shape evaluation> By the above operation, the dimensions La of the lower side and Lb of the upper side of the cross-section of the shape 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 7. ◎: 0.90 ≦ La / Lb ≦ 1 ○: 0.85 ≦ La / Lb < 0.90 ×: La / Lb < 0.85

[0279]

Table 7

[0280] In the results of Table 1 and Table 7, comparing Examples N1 to N5 of the photoacid generator (sulfonium salt) with Comparative Examples HN1 to HN2, Examples N6 to N9 with Comparative Example HN3, Example N10 with Comparative Example HN4, Example N11 with Comparative Example HN5, Example N12 with Comparative Example HN6, and Example N13 with Comparative Example HN7, the photoacid generator of the present invention, compared with the comparative photoacid generator, although the light absorption does not increase significantly, by having the substituent A1 or A2 in the general formula (1), it has excellent photosensitivity when used as a chemically amplified negative resist.

Industrial applicability

[0281] The sulfonium salt of the present invention is suitably used as a photoacid generator for paints, coating agents, various coating materials (hard coats, stain-resistant coatings, antifogging coatings, corrosion-resistant coatings, optical fibers, etc.), back surface treatment agents for adhesive tapes, release coating materials for release sheets for adhesive labels (release papers, release plastic films, release metal foils, etc.), printed boards, dental materials (dental formulations, dental composites), inks, inkjet inks, positive resists (formation of connection terminals and wiring patterns for manufacturing electronic components such as circuit boards, CSPs, MEMS elements, etc.), resist films, liquid resists, negative resists (permanent film materials such as surface protection films, interlayer insulation films, planarization films for semiconductor elements, etc.), resists for MEMS, positive photosensitive materials, negative photosensitive materials, various adhesives (temporary fixing agents for various electronic components, adhesives for HDDs, adhesives for pickup lenses, adhesives for functional films for FPDs (deflection plates, antireflection films, etc.)), holographic resins, FPD materials (color filters, black matrices, partition materials, photospacers, ribs, alignment films for liquid crystals, sealants for FPDs, etc.), optical members, molding materials (for building materials, optical parts, lenses), casting materials, putties, glass fiber impregnants, caulking materials, sealing materials, encapsulants for optical semiconductors (LEDs), optical waveguide materials, nanoimprint materials, materials for optical modeling, and materials for micro-optical modeling, etc.

Claims

1. A sulfonium salt represented by the following general formula (1). 【Chemical 1】 [In formula (1), R1 and R2 each independently represent an aryl group having 6 to 14 carbon atoms, and a part of the hydrogen atoms of these aryl groups may be substituted with a substituent (t). The substituent (t) is an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 10 carbon atoms, and these substituents (t) are directly bonded to R1 and R2 by a single bond, or through any of the groups represented by -SO-, -SO ２ -, or -CO-. A1 and A2 each independently represent a hydrogen atom, a branched alkyl group having 3 to 7 carbon atoms, a branched alkoxy group having 3 to 7 carbon atoms, a tertiary silyl group having 3 to 9 carbon atoms selected from trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl and triisopropylsilyl, or a tertiary siloxy group having 3 to 9 carbon atoms selected from trimethylsiloxy, triethylsiloxy, tert-butyldimethylsiloxy and triisopropylsiloxy, provided that A1 and A2 are not simultaneously hydrogen atoms. T1 and T2 each independently represent an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, a silyl group having 3 to 9 carbon atoms selected from trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl and triisopropylsilyl, or a siloxy group having 3 to 9 carbon atoms selected from trimethylsiloxy, triethylsiloxy, tert-butyldimethylsiloxy and triisopropylsiloxy. m1 and m2 each represent the number of T1 and T2, respectively, m1 is an integer of 0 to 3, and m2 is an integer of 0 to 4. L is a group represented by -O-, -S-, -SO-, -SO ２ -, or -CO-, S is a sulfur atom, O is an oxygen atom, C is a carbon atom, X － represents a monovalent polyatomic anion.]

2. The sulfonium salt according to claim 1, wherein A1 and A2 are each a group selected from a tert-butyl group, a tert-butoxy group, and a trimethylsiloxy group.

3. L is a group represented by -S-, -SO- or -SO₂- ２ The sulfonium salt according to claim 1 or 2, wherein L is a group represented by -S-, -SO- or -SO₂- and R₁ and R₂ are the same group.

4. X － is MY ａ － , (Rf) ｂ PF ６－ｂ － , R ３ ｃ , BY ４－ｃ － , R ３ ｃ , Gay ４－ｃ － , R ４ , SO ３ － , (R ４ , SO ２ ), ３ , C － or (R ４ , SO ２ ), ２ , N － and is an anion represented by (M is a phosphorus atom, a boron atom, an arsenic atom or an antimony atom, Y is a halogen atom, Rf is an alkyl group in which 80 mol% or more of hydrogen atoms are substituted with fluorine atoms, P is a phosphorus atom, F is a fluorine atom, R ３ is a phenyl group in which at least one hydrogen atom is substituted with a halogen atom, a trifluoromethyl group, a nitro group or a cyano group, B is a boron atom, Ga is a gallium atom, R ４ is 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, S is a sulfur atom, O is an oxygen atom, C is a carbon atom, N is a nitrogen atom, a represents an integer of 4 to 6, b represents an integer of 1 to 5, and c represents an integer of 1 to 4). The sulfonium salt according to any one of claims 1 to 3.

5. X － is SbF ６ － 、PF ６ － 、BF ４ － 、(CF ３ CF ２ ) ３ PF ３ － 、(CF ３ CF ２ CF ２ CF ２ ) ３ PF ３ －、 (C ６ F ５ ) ４ B － 、(C ６ H ５ )(C ６ F ５ ) ３ 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 － 、an anion represented by trifluoromethanesulfonate anion, nonafluorobutanesulfonate anion, methanesulfonate anion, camphorsulfonate anion, benzenesulfonate anion or p-toluenesulfonate anion, the sulfonium salt according to any one of claims 1 to 4.

6. A photoacid generator comprising the sulfonium salt according to any one of claims 1 to 5.

7. An energy ray-curable composition comprising the photoacid generator according to claim 6 and a cationically polymerizable compound.

8. A cured body obtained by curing the energy ray-curable composition according to claim 7.

9. A chemically amplified positive photoresist composition comprising component (A) containing the photoacid generator according to claim 6 and component (B) which is a resin whose solubility in alkali increases by the action of an acid.

10. The chemically amplified positive photoresist composition according to claim 9, wherein component (B) which is a resin whose solubility in alkali increases by the action of an acid comprises at least one resin selected from the group consisting of a novolak resin (B1), a polyhydroxystyrene resin (B2), and an acrylic resin (B3).

11. The chemically amplified positive photoresist composition according to claim 9 or 10, further comprising an alkali-soluble resin (C) and an acid diffusion control agent (D).

12. A step of laminating a photoresist layer having a film thickness of 5 to 150 μm made of the chemically amplified positive photoresist composition according to any one of claims 9 to 11 on a support to obtain a photoresist laminate, an exposure step of selectively irradiating the photoresist laminate with light or radiation, and a development step of developing the photoresist laminate after the exposure step to obtain a resist pattern, the method for producing a resist pattern being characterized by including these steps.

13. A chemically amplified negative photoresist composition comprising component (E) containing the photoacid generator according to claim 6, component (F) which is an alkali-soluble resin having a phenolic hydroxyl group, and a crosslinking agent component (G).

14. The chemically amplified negative photoresist composition according to claim 13, further comprising a crosslinked fine particle component (H).

15. A cured body obtained by curing the chemically amplified negative photoresist composition according to claim 13 or 14.

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