Novel onium salts and photoacid generators

Abstract

The present application functions as a photoacid generator, and further provides a chemical amplification type photoresist composition by combining the photoacid generator with a resin whose solubility in a base is increased by the action of an acid generated by irradiation of active energy rays such as light or electron rays. The present application relates to an onium salt which is an onium salt represented by General Formula (1), wherein, of the two isomers of a facial isomer and a mer isomer in the anion structure, the proportion of the facial isomer is 15.0% by weight or less. 2 ) n+1 -E] + [(R 1 )3(F)3P] ‑ (1).

Description

Technical Field

[0001] The present invention relates to a novel onium salt and a novel onium salt-type photoacid generator. More specifically, it relates to a photoacid generator suitable as a resin composition for chemically amplified resists used in pattern formation of semiconductors. Background Art

[0002] Conventionally, photoacid generators that generate acid by irradiation with active energy rays such as light or electron beams are known. These photoacid generators are also widely known as photoacid generators for resists (Patent Documents 1 and 2).

[0003] In addition, as anions described in these specifications, sulfonates, BF4 - PF6 - 、AsF6 - 、SbF6 - From the perspective of the toxicity of As and Sb, the use of AsF6 is avoided in resist materials, especially in the field of semiconductor resists. - 、SbF6 - , and BF4 - PF6 - The acid strength is weak, making it extremely inconvenient to use. Furthermore, special phosphorus-based substances are described, but they cannot be said to exhibit sufficient sensitivity (Patent Document 3). There are also documents describing methods for producing these special phosphorus-based substances, but even using these methods, no useful photoacid generators have been discovered (Patent Document 4).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-193925

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2001-354669

[0008] Patent Document 3: WO2005 / 116038

[0009] Patent Document 4: Japanese Patent Application No. 2004-533473 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] Therefore, the present inventors have found that by having a specific anion structure and controlling the stereoisomers of the anion structure within a certain range, high sensitivity can be specifically exhibited when used as a resist material, thereby completing the present invention.

[0012] Means for solving problems

[0013] The present inventors synthesized the onium salt represented by the general formula (1) below, and found that it is suitable for the above purpose, wherein, among the two isomers of facial and meridional structures of the anion structure, the proportion of the facial isomer is 15.0% by weight or less.

[0014] [(R 2 ) n+1 -E] + [(R 1 )3(F)3P] - (1)

[0015] In the formula (1), R 1 is a halogen atom-substituted alkyl group having 1 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms (excluding the number of carbon atoms of the substituent below). Some of the hydrogen atoms in the aryl group can be substituted with an alkyl group having 1 to 18 carbon atoms, a halogen atom, a halogen atom-substituted alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, or an alkynyl group having 2 to 18 carbon atoms;

[0016] E represents an element of Group 15 to 17 (IUPAC) having a valence of n, and n is an integer of 1 to 3, and R 2 is an organic group bonded to E, the number of R 2 is n+1, and (n+1) R 2 each can be the same as or different from each other, and two or more R 2 may form a ring structure including the element E directly or via -O-, -S-, -SO-, -SO2-, -NH-, -CO-, -COO-, -CONH-, an alkylene group, or a phenylene group.

[0017] Effects of the Invention

[0018] The onium salt of the present invention functions as a photoacid generator, and further, this photoacid generator forms a chemically amplified photoresist composition by being combined with a resin whose solubility in a base is increased under the action of an acid generated by irradiation of active energy rays such as light or electron rays. The onium salt of the present invention specifically exerts effects when used for this purpose.

[0019] That is, a chemically amplified positive photoresist composition and a chemically amplified negative photoresist composition using an acid generator containing the onium salt of the present invention can obtain a high-sensitivity resist (a pattern can be formed at a low exposure amount compared with the past). Furthermore, the resist pattern shape of the chemically amplified positive photoresist composition and the chemically amplified negative photoresist composition of the present invention is good. DETAILED DESCRIPTION

[0020] Hereinafter, the embodiments of the present application will be described in detail.

[0021] The onium salt of the present application is represented by the following general formula (1).

[0022] An onium salt which is an onium salt represented by general formula (1), wherein the proportion of the facial isomer is 15.0% by weight or less among the two isomers of facial isomer and mer isomer.

[0023] [(R 2 ) n+1 -E] + [(R 1 )3(F)3P] - (1)

[0024] In formula (1), R 1 is an alkyl group having 1 to 18 carbon atoms which is substituted with a halogen atom, or an aryl group having 6 to 18 carbon atoms (excluding the number of carbon atoms of the substituent described below). Some of the hydrogen atoms in the aryl group can be substituted with an alkyl group having 1 to 18 carbon atoms, a halogen atom, an alkyl group having 1 to 8 carbon atoms which is substituted with a halogen atom, an alkenyl group having 2 to 18 carbon atoms, or an alkynyl group having 2 to 18 carbon atoms;

[0025] E represents an element of Group 15 to 17 (IUPAC) having a valence of n, n is an integer of 1 to 3, and R 2 is an organic group bonded to E, the number of R 2 is n+1, and (n+1) R 2 each can be the same as or different from each other, and two or more R 2 may form a ring structure including the element E directly or via -O-, -S-, -SO-, -SO2-, -NH-, -CO-, -COO-, -CONH-, an alkylene group, or a phenylene group.

[0026] In the anion (B) of the onium salt (A) of the present application, P represents a phosphorus atom, and F represents a fluorine atom. In addition, R 1 is an alkyl group having 1 to 18 carbon atoms which is substituted with a halogen atom, or an aryl group having 6 to 18 carbon atoms (excluding the number of carbon atoms of the substituent described below). Some of the hydrogen atoms in the aryl group can be substituted with an alkyl group having 1 to 18 carbon atoms, a halogen atom, an alkyl group having 1 to 8 carbon atoms which is substituted with a halogen atom, an alkenyl group having 2 to 18 carbon atoms, or an alkynyl group having 2 to 18 carbon atoms.

[0027] This anion (B) has the following structure: P is the central element, and F and R 1 each of the three, a total of six, are coordinated. In this case, there are two isomers: a facial isomer in which the same kind of ligand is in cis to each other, and a mer isomer in which the same ligand is located on the same plane.

[0028] In the case where the onium salt (A) functions as an acid generator, a substance obtained by adding a proton to the anion (B) functions as an acid, and therefore it is extremely important to control the amount ratio of the two isomers. By making the proportion of the s-trans isomer in the two isomers of the s-trans isomer and the s-cis isomer 15.0% by weight or less, a resist whose sensitivity is dramatically improved (a pattern can be formed at a lower exposure amount than in the past) can be produced. The proportion of the s-trans isomer in the two isomers of the s-trans isomer and the s-cis isomer is more preferably in the range of 0.1 to 15.0% by weight, and most preferably in the range of 0.5 to 10.0% by weight.

[0029] R 1 is a halogen atom-substituted alkyl group having 1 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms (excluding the number of carbon atoms of the substituents described below). In the aryl group, some of the hydrogen atoms can be substituted with an alkyl group having 1 to 18 carbon atoms, a halogen atom, a halogen atom-substituted alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, or an alkynyl group having 2 to 18 carbon atoms. Examples of these substituents are the same as those described below for R 2 . Of these, a perfluoroalkyl group, a phenyl group substituted with a fluorine atom is preferable, and specifically, a pentafluoroethyl group, a heptafluoro-n-propyl group, a nonafluoro-n-butyl group, a heptafluoroisopropyl group, a trifluoromethyl group, and the like are more preferable.

[0030] In order to control the amount ratio of the s-trans isomer and the s-cis isomer as the two isomers, for example, by optimizing the polarity of the solvent at the time of the reaction of the phosphorane (R 1 )3(F)2P) as the precursor with a fluorinating agent, the amount of the solvent and the substrate, that is, the concentration, and the reaction temperature, control can be performed to synthesize the isomer in accordance with the purpose. Note that examples of the fluorinating agent include hydrogen fluoride, metal fluorides (sodium fluoride, potassium fluoride), and the like.

[0031] The cation (C) of the onium salt (A) is a cationic site of the general formula (1), E represents an element of Groups 15 to 17 (IUPAC) having a valence of n, n is an integer of 1 to 3, and R 2 is an organic group bonded to E, the number of R 2 is n+1, and the (n+1) R 2 may each be the same as or different from one another, and two or more R 2 may form a ring structure including the element E directly or via -O-, -S-, -SO-, -SO2-, -NH-, -CO-, -COO-, -CONH-, an alkylene group, or a phenylene group.

[0032] As specific examples of E, there can be mentioned N, O, F, P, S, Cl, As, Se, Br, Sb, Te, I, etc., in terms of element symbols. Of these, preferred elements are S, I, N and P. As the corresponding cation (C), there are sulfonium, iodonium, ammonium, phosphonium. Further preferred elements are S and I. As the corresponding cation (C), there are sulfonium and iodonium.

[0033] R 2 R 2 There can be mentioned alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms and aryl groups having 6 to 18 carbon atoms, and the aryl group can be further substituted with alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, aryl groups having 6 to 18 carbon atoms, nitro groups, hydroxy groups, cyano groups, -OR 5 alkoxy groups or aryloxy groups represented by the formula: -OR 6 alkylthio groups or arylthio groups represented by the formula: -SR 7 acyl groups represented by the formula: -COR 8 acyloxy groups represented by the formula: -COOR 9 amino groups represented by the formula: -NR 10 or halogen atoms.

[0034] As the alkyl groups having 1 to 18 carbon atoms in the above R 2 there can be mentioned straight-chain alkyl groups (methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl and n-octadecyl, etc.), branched-chain alkyl groups (isopropyl, isobutyl, sec-butyl, t-butyl, isopentyl, neopentyl, t-pentyl, isohexyl, 2-ethylhexyl and 1,1,3,3-tetramethylbutyl, etc.), cyclic alkyl groups (cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl, etc.), cross-linked cyclic alkyl groups (norbornyl, adamantyl and pinanyl, etc.) and arylalkyl groups (benzyl, naphthylmethyl, phenethyl, benzhydryl and phenacyl, etc.).

[0035] As the alkenyl groups having 2 to 18 carbon atoms in the above R 2 there can be mentioned straight-chain or branched-chain alkenyl groups (vinyl, allyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-1-propenyl and 2-methyl-2-propenyl, etc.), cyclic alkenyl groups (2-cyclohexenyl and 3-cyclohexenyl, etc.) and arylalkenyl groups (styryl and cinnamyl, etc.).

[0036] As the aryl groups having 6 to 18 carbon atoms in the above R 2The aryl group having 6 to 18 carbon atoms (excluding the carbon atoms of the substituents described below) in the formula (a) may include monocyclic aryl groups (such as phenyl), condensed polycyclic aryl groups (such as naphthyl, anthracenyl, phenanthrenyl, anthraquinone, fluorenyl and naphthoquinolinyl), and aromatic heterocyclic hydrocarbon groups (monocyclic heterocycles such as thienyl, furanyl, pyranyl, pyrrolyl, oxazolyl, thiazolyl, pyridyl, pyrimidinyl and pyrazinyl; and indole; (including condensed polycyclic heterocycles such as benzothiophene, benzofuranyl, isobenzofuranyl, benzothiophenyl, isobenzothiophenyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, carbazolyl, acridinyl, phenothiazinyl, phenazinyl, xanthenyl, thianthrenyl, phenoxazinyl, phenoxathiyl, chromanyl, isochromanyl, coumarinyl, dibenzothiophenyl, xanthonyl, thioxanthonyl, and dibenzofuranyl).

[0037] In addition to the above, some of the hydrogen atoms in the aryl group may be replaced by an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, a nitro group, a hydroxyl group, a cyano group, a -OR 5 The alkoxy or aryloxy group shown, -SR 6 The alkylthio or arylthio group shown, R 7 Acyl represented by CO-, R 8 Acyloxy represented by COO-, -NR 9 R 10 The group is substituted by the amino group or a halogen atom.

[0038] Among the above substituents, -OR 5 The alkoxy group shown, -SR 6 The alkylthio group, R 7 Acyl represented by CO-, R 8 Acyloxy represented by COO-, -NR 9 R 10 The amino group R 5 ~R 10 , an alkyl group having 1 to 8 carbon atoms can be mentioned, and specifically, an alkyl group having 1 to 8 carbon atoms among the above-mentioned alkyl groups can be mentioned.

[0039] Among the above substituents, -OR 5 The aryloxy group, -SR 6 The arylthio group shown, R 7 Acyl represented by CO-, R 8 Acyloxy represented by COO-, -NR 9 R 10 The amino group R 5 ~R 10 , an aryl group having 6 to 18 carbon atoms can be mentioned, and specifically, the above-mentioned aryl groups having 6 to 18 carbon atoms can be mentioned.

[0040] as -OR 5 As the alkoxy group represented by -OR

[0041] as -OR 5 As the aryloxy group represented by -OR

[0042] As the alkylthio group represented by -SR 6 As the alkylthio group represented by -SR

[0043] As the arylthio group represented by -SR 6 As the arylthio group represented by -SR

[0044] As the acyl group represented by -CO- 7 As the acyl group represented by -CO-

[0045] As the acyloxy group represented by -COO- 8 As the acyloxy group represented by -COO-

[0046] As the amino group represented by -NR 9 R 10 As the amino group represented by -NR

[0047] As the halogen atom, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom can be mentioned.

[0048] In the above R 2 , an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms and an aryl group having 6 to 18 carbon atoms substituted by a nitro group, a hydroxyl group, an alkyl group having 1 to 18 carbon atoms, an alkoxy group represented by -OR 5 , an arylthio group represented by -SR 6 , an acyl group represented by -CO- 7 , an acyloxy group represented by -COO- or a chlorine atom are preferred.

[0049] Further, an alkyl group having 1 to 18 carbon atoms, a phenyl group and a phenyl group substituted by a hydroxyl group, an alkyl group having 1 to 18 carbon atoms, an alkoxy group represented by -OR 5 , an arylthio group represented by -SR 6 , an acyl group represented by -CO- 2 , an acyloxy group represented by -COO- or a chlorine atom are further preferred.

[0050] In addition, two or more R 2 may form a ring structure containing the element E, directly or via -0-, -S-, -SO-, -SO2-, -NH-, -CO-, -COO-, -CONH-, alkylene, or phenylene.

[0051] The following illustrates specific examples of the cation (C).

[0052] As specific examples of the ammonium ion, tetramethylammonium, ethyltrimethylammonium, diethyldimethylammonium, triethylmethylammonium, tetraethylammonium, and the like tetraalkylammonium; N,N-dimethylpyrrolidinium, N-ethyl-N-methylpyrrolidinium, N,N-diethylpyrrolidinium, and the like pyrrolidinium; N,N'-dimethylimidazolium, N,N'-diethylimidazolium, N-ethyl-N'-methylimidazolium, 1,3,4-trimethylimidazolium, 1,2,3,4-tetramethylimidazolium, and the like imidazolium; N,N'-dimethyltetrahydropyrimidinium, and the like tetrahydropyrimidinium; N,N'-dimethylmorpholinium, and the like morpholinium; N,N'-diethylpiperidinium, and the like piperidinium; N-methylpyridinium, N-benzylpyridinium, N-benzoylmethylpyridinium, and the like pyridinium; N,N'-dimethylimidazole, and the like imidazole; N-methylquinolinium, N-benzylquinolinium, N-benzoylmethylquinolinium, and the like quinolinium; N-methylisoquinolinium, and the like isoquinolinium; benzylbenzothiazolium, benzoylmethylbenzothiazolium, and the like thiazolium; benzylacridinium, benzoylmethylacridinium, and the like acridinium can be given.

[0053] As specific examples of the phosphonium ion, tetraphenylphosphonium, tetra-p-tolylphosphonium, tetra(2-methoxyphenyl)phosphonium, tetra(3-methoxyphenyl)phosphonium, tetra(4-methoxyphenyl)phosphonium, and the like tetraarylphosphonium; triphenylbenzylphosphonium, triphenylbenzoylmethylphosphonium, triphenylmethylphosphonium, triphenylbutylphosphonium, and the like triarylphosphonium; triethylbenzylphosphonium, tributylbenzylphosphonium, tetraethylphosphonium, tetrabutylphosphonium, tetrahexylphosphonium, triethylbenzoylmethylphosphonium, tributylbenzoylmethylphosphonium, and the like tetraalkylphosphonium can be given.

[0054] Specific examples of the sulfonium ion include triphenylsulfonium, tri-p-tolylsulfonium, tri-o-tolylsulfonium, tri(4-methoxyphenyl)sulfonium, 1-naphthyldiphenylsulfonium, 2-naphthyldiphenylsulfonium, tri(4-fluorophenyl)sulfonium, tri-1-naphthylsulfonium, tri-2-naphthylsulfonium, tri(4-hydroxyphenyl)sulfonium, 4-(phenylthio)phenyldiphenylsulfonium, 4-(p-tolylsulfonium)phenyldi-p-tolylsulfonium, 4-(4-methoxyphenylthio)phenylbis(4-methoxyphenyl)sulfonium, 4-(phenylthio)phenylbis(4-fluorophenyl)sulfonium, 4-(phenylthio)phenylbis(4-methoxyphenyl)sulfonium, 4-(phenylthio)phenyldi-p-tolylsulfonium, Tolylsulfonium, [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium, [4-(2-thioxanthonylthio)phenyl]diphenylsulfonium, bis[4-(diphenylsulfonyl)phenyl]sulfide, bis[4-{bis[4-(2-hydroxyethoxy)phenyl]sulfonyl}phenyl]sulfide, bis{4-[bis(4-fluorophenyl)sulfonyl]phenyl}sulfide, bis{4-[bis(4-methylphenyl)sulfonyl]phenyl}sulfide, bis{4-[bis(4-methoxyphenyl)sulfonyl]phenyl}sulfide, 4-(4-benzoyl-2-chlorophenylthio)phenylbis(4-fluorophenyl)sulfonium, 4-(4-benzoyl) 2-chlorophenylthio)phenyldiphenylsulfonium, 4-(4-benzoylphenylthio)phenylbis(4-fluorophenyl)sulfonium, 4-(4-benzoylphenylthio)phenyldiphenylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldi-p-tolylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldiphenylsulfonium, 2-[(di-p-tolyl)sulfonyl]thioxanthone, 2-[(diphenyl)sulfonyl]thioxanthone, 4-(9-oxo-9H-thioxanthen-2-yl)thiophenyl-9-oxo-9H-thioxanthen-2-ylphenylsulfonium, 4-[4-(4 triarylsulfoniums such as 4-[4-(4-tert-butylbenzoyl)phenylthio]phenyldi-p-tolylsulfonium, 4-[4-(benzoylphenylthio)]phenyldi-p-tolylsulfonium, 4-[4-(benzoylphenylthio)]phenyldi-p-tolylsulfonium, 4-[4-(benzoylphenylthio)]phenyldiphenylsulfonium, 5-(4-methoxyphenyl)thianthrenium, 5-phenylthianthrenium, 5-tolylthianthrenium, 5-(4-ethoxyphenyl)thianthrenium, and 5-(2,4,6-trimethylphenyl)thianthrenium; diarylsulfoniums such as diphenylphenacylsulfonium, diphenyl-4-nitrophenacylsulfonium, diphenylbenzylsulfonium, and diphenylmethylsulfonium;monofunctional onium salt, such as phenylmethylbenzylsulfonium, 4-hydroxyphenylmethylbenzylsulfonium, 4-methoxyphenylmethylbenzylsulfonium, 4-acetoxyphenylmethylbenzylsulfonium, 4-acetoxyphenyldimethylsulfonium, 4-hydroxyphenyl(l-naphthylmethyl)methylsulfonium, 2-naphthylmethylbenzylsulfonium, 4-hydroxyphenyl(4-nitrobenzyl)methylsulfonium, 2-naphthylmethyl(l-ethoxycarbonyl)ethylsulfonium, phenylmethylbenzoylmethylsulfonium, 4-hydroxyphenylmethylbenzoylmethylsulfonium, 4-methoxyphenylmethylbenzoylmethylsulfonium, 4-acetoxyphenylmethylbenzoylmethylsulfonium, 2-naphthylmethylbenzoylmethylsulfonium, 2-naphthylstearylbenzoylmethylsulfonium, 9-anthrylmethylbenzoylmethylsulfonium, and the like; dimethylbenzoylmethylsulfonium, benzoylmethyltetrahydrothiophenium, benzyltetrahydrothiophenium, stearylmethylbenzoylmethylsulfonium, and the like.

[0055] As specific examples of the iodonium ion, there can be mentioned diphenyliodonium, di-p-tolyliodonium, di(4-tert-butylphenyl)iodonium, di(4-dodecylphenyl)iodonium, di(4-methoxyphenyl)iodonium, (4-octyloxyphenyl)phenyl iodonium, di(4-decyloxyphenyl)iodonium, 4-(2-hydroxytetradecyloxy)phenylphenyl iodonium, 4-isopropylphenyl(p-tolyl)iodonium, phenyl(2,4,6-trimethoxyphenyl)iodonium, and 4-isobutylphenyl(p-tolyl)iodonium, and the like.

[0056] The onium salt represented by formula (1) of the present application can be produced by a metathesis method. The metathesis method is described, for example, in "Shin Jikken Kagaku Koza 14-I" (1978, Maruzen), p. 448; "Advance in Polymer Science", 62, 1-48 (1984); "Shin Jikken Kagaku Koza 14-III" (1978, Maruzen), p. 1838-1846; "Yuki Shokubai Kagaku (Synthetic Reaction Edition)", 1982, Chemical Daily, Chapter 8, p. 237-280; "Nippon Kagaku Zasshi", 87, (5), 74 (1966); Japanese Patent Application Laid-Open No. 64-45357, Japanese Patent Application Laid-Open No. 61-212554, Japanese Patent Application Laid-Open No. 61-100557, Japanese Patent Application Laid-Open No. 5-4996, Japanese Patent Application Laid-Open No. 7-82244, Japanese Patent Application Laid-Open No. 7-82245, Japanese Patent Application Laid-Open No. 58-210904, Japanese Patent Application Laid-Open No. 6-184170, and the like, and first produces a halogen ion salt of F - , Cl - , Br - , I - , and the like; OH - , and the like; ClO4 - , and the like; and FSO3 - , ClSO3 - , CH3SO3 -, C6H5SO3 - , CF3SO3 - salts of sulfonic acid ions such as HSO4 - , SO4 2- salts of sulfate ions such as HCO3 - , CO3 2- salts of carbonate ions such as H2PO4 - , HPO4 2- , PO4 3- salts of phosphoric acid ions such as the like are added to the alkali metal salt, the alkaline earth metal salt or the quaternary ammonium salt of the anion constituting the onium salt of formula (1), the solvent and the aqueous solution, and double decomposition is performed. As the solvent, water, an organic solvent can be used. As the organic solvent, a hydrocarbon (hexane, heptane, toluene, xylene and the like), a cyclic ether (tetrahydrofuran and dioxane and the like), a chlorine-based solvent (chloroform and dichloromethane and the like), an alcohol (methanol, ethanol and isopropanol and the like), a ketone (acetone, methyl ethyl ketone and methyl isobutyl ketone and the like), a nitrile (acetonitrile and the like) and a polar organic solvent (dimethyl sulfoxide, dimethylformamide and N-methylpyrrolidone and the like) are included. These solvents can be used alone or two or more can be used in combination.

[0057] The onium salt of interest thus produced is isolated as a crystal or an oil. In the case of an oil, the oil is isolated by separation from the organic solvent solution, and further the organic solvent contained in the oil is removed by distillation. In the case of a crystal, the solid is isolated by separation from the organic solvent solution, and further the organic solvent contained in the solid is removed by distillation. The onium salt of interest thus obtained can be refined as necessary by recrystallization or by a method using water, a solvent, washing and the like.

[0058] The refinement by recrystallization can be performed as follows: the onium salt of interest is dissolved with a small amount of an organic solvent, and a poor solvent is added directly (or after concentration) to the organic solvent solution containing the onium salt of interest to precipitate the onium salt of interest, whereby separation from the organic solvent is performed. As the poor solvent used here, a chain ether (diethyl ether and dipropyl ether and the like), an ester (ethyl acetate and butyl acetate and the like), an aliphatic hydrocarbon (hexane and cyclohexane and the like) and an aromatic hydrocarbon (toluene and xylene and the like) are included. In addition, refinement can be performed using the solubility difference due to temperature. The refinement can be performed by recrystallization (a method using the solubility difference due to cooling, a method of precipitating by adding a poor solvent and a combination of these methods). In addition, in the case where the object is an oil (in the case of not crystallizing), refinement can be performed by a method of washing the oil with water or a poor solvent.

[0059] In the case of using the onium salt of formula (1), in order to be easily dissolved in a chemically amplified resist composition, it can be dissolved in advance in a solvent which does not inhibit polymerization, crosslinking, deprotection reaction and the like.

[0060] As the solvent, 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 isopentyl ketone and 2-heptanone; polyhydric alcohols and derivatives thereof such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol and dipropylene glycol monoacetate, monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether; 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; aromatic hydrocarbons such as toluene and xylene; and the like can be mentioned.

[0061] In the case of using a solvent, the proportion of the solvent used is preferably 15 to 1000 parts by weight, further preferably 30 to 500 parts by weight, relative to 100 parts by weight of the onium salt of the formula (1) of the present application. The solvent used can be used alone or in combination of two or more.

[0062] By using the onium salt of the present application as a photoacid generator and further by mixing various components, an energy ray-curable composition is formed. This composition can be cured by irradiation of energy rays to obtain a cured body.

[0063] As the energy ray, any energy ray having an energy to induce decomposition of the photoacid generator of the present application can be used, and an energy ray in the ultraviolet to visible light region (wavelength: about 100 nm to about 800 nm) obtained from a low-pressure, medium-pressure, high-pressure or super-high-pressure mercury lamp, a metal halide lamp, an LED lamp, a xenon lamp, a carbon arc lamp, a fluorescent lamp, a semiconductor solid laser, an argon laser, a He-Cd laser, a KrF excimer laser, an ArF excimer laser or an F2 laser is preferred. Note that an electron beam or an X-ray or the like having a high energy can also be used as the energy ray.

[0064] The irradiation time of the energy rays is influenced by the intensity of the energy rays and the permeability of the energy rays to the energy ray-curable composition, and is preferably 0.1 to 10 seconds or so at ordinary temperature (20 to 30°C or so). However, in the case where the permeability of the energy rays is low, in the case where the film thickness of the energy ray-curable composition is thick, and the like, it is sometimes preferred to irradiate for a time longer than the above. Most of the energy ray-curable composition is cured by cationic polymerization after the energy ray irradiation for 0.1 seconds to several minutes, but if necessary, it is also possible to perform post-curing by heating at room temperature (20 to 30°C or so) to 200°C for several seconds to several hours after the energy ray irradiation.

[0065] As the specific use of the energy ray-curable composition, there can be mentioned a positive resist (formation of a connection terminal or a wiring pattern for electronic parts manufacturing such as a circuit substrate, a CSP, a MEMS element, and the like), a negative resist (permanent film materials such as a surface protective film, an interlayer insulating film, a planarization film, and the like for a semiconductor element and the like), and the like.

[0066] As the chemically amplified resist materials, there are included: (1) a 2-component system chemically amplified positive resist using a resin which is soluble in an alkali developing solution under the action of an acid and a photo-acid generator as essential components; (2) a 3-component system chemically amplified positive resist using a resin which is soluble in an alkali developing solution, a dissolution inhibitor which is soluble in an alkali developing solution under the action of an acid, and a photo-acid generator as essential components; and (3) a chemically amplified negative resist using a resin which is soluble in an alkali developing solution, a crosslinking agent which makes the resin insoluble in an alkali developing solution by performing a heating treatment in the presence of an acid, and a photo-acid generator as essential components.

[0067] In the chemically amplified positive photoresist compositions of the above (1) and (2), the onium salt (A) of the present application as a compound which generates an acid by light or radiation irradiation functions as an acid generator, and the chemically amplified positive photoresist composition contains a resin component (F) whose solubility in an alkali is increased under the action of the acid.

[0068] In the solid components of the chemically amplified positive photoresist composition, the content of the onium salt (A) is preferably 0.05 to 5% by weight.

[0069] <Resin Component (F) Whose Solubility in an Alkali is Increased under the Action of an Acid>

[0070] The above "resin (F) whose solubility in an alkali is increased under the action of an acid" used in the chemically amplified positive photoresist composition of the present application (hereinafter referred to as "component (F)" in the present specification) is at least one resin selected from the group consisting of a novolak resin (Fl), a polyhydroxystyrene resin (F2), and an acrylic resin (F3), or a mixed resin or a copolymer thereof.

[0071] [Novolak resin (F1)]

[0072] As the novolak resin (F1), a resin represented by the following general formula (bl) can be used.

[0073] [Chem. 1]

[0074]

[0075] In the above general formula (bl), R 1b represents an acid dissociation solubility inhibiting group, R 2b represents an acid dissociation solubility inhibiting group, and n represents the number of repeating units of the structure within the parentheses. 3b Each of R

[0076] Further, as the acid dissociation solubility 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.

[0077] Here, as specific examples of the acid dissociation solubility inhibiting group represented by the above R 1b , methoxyethyl group, ethoxyethyl group, n-propoxyethyl group, isopropoxyethyl group, n-butoxyethyl group, isobutoxyethyl group, t-butoxyethyl group, cyclohexyloxyethyl group, methoxypropyl group, ethoxypropyl group, 1-methoxy-l-methyl-ethyl group, 1-ethoxy-l-methylethyl group, t-butyloxycarbonyl group, t-butyloxycarbonylmethyl group, trimethylsilyl group, and tri-t-butyldimethylsilyl group, and the like can be given.

[0078] [Polyhydroxystyrene resin (F2)]

[0079] As the polyhydroxystyrene resin (F2), a resin represented by the following general formula (b4) can be used.

[0080] [Chem. 2]

[0081]

[0082] 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 dissociation solubility inhibiting group, and n represents the number of repeating units of the structure within the parentheses.

[0083] The above alkyl group having 1 to 6 carbon atoms is a linear alkyl group having 1 to 6 carbon atoms or a branched alkyl group having 3 to 6 carbon atoms, a cyclic alkyl group having 3 to 6 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like, and as the cyclic alkyl group, a cyclopentyl group, a cyclohexyl group, and the like can be given.

[0084] As the above R 9b The acid dissociation solubility-inhibiting group represented by the above R 1b The acid dissociation solubility-inhibiting group represented by the above R

[0085] Further, in the polyhydroxystyrene resin (F2), other polymerizable compounds can be contained as a structural unit for the purpose of moderately controlling physical and chemical properties. As such polymerizable compounds, publicly known radical polymerizable compounds, anionic polymerizable compounds can be given. Examples thereof include monocarboxylic acids such as acrylic acid; dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid; methacrylic acid derivatives having a carboxyl group and an ester bond such as 2-methacryloyloxyethyl succinic acid; (meth)alkyl acrylates such as methyl (meth)acrylate; (meth)hydroxyalkyl acrylates such as 2-hydroxyethyl (meth)acrylate; dicarboxylic acid diesters such as diethyl maleate; vinyl group-containing aromatic compounds such as styrene, vinyltoluene; vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated dienes such as butadiene, 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.

[0086] [Acrylic resin (F3)]

[0087] As the acrylic resin (F3), a resin represented by the following general formulae (b5) to (b10) can be used.

[0088] [Chem. 3]

[0089]

[0090] [Chem. 4]

[0091]

[0092] In the above general formulae (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 fluoroalkyl group having 1 to 6 carbon atoms or a branched fluoroalkyl 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, Y b represents an aliphatic ring group or an alkyl group which can have a substituent, n represents the number of repeating units of the structure within the parentheses, p is an integer of 0 to 4, and q is 0 or 1.

[0093] In General Formula (b8), General Formula (b9), and General Formula (b10), R 18b , R 20b , and R 21b independently of one another represent a hydrogen atom or a methyl group, in General Formula (b8), each R 19b independently of one another represent a hydrogen atom, a hydroxyl group, a cyano group, or a COOR 23b group (wherein 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 cyclic alkyl group having 3 to 20 carbon atoms), in General Formula (b10), each R 22b independently of one another represent a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group having 3 to 4 carbon atoms, or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, and at least one of R 22b is the alicyclic hydrocarbon group or the derivative thereof; or any two R 22b bond to each other and form, together with the common carbon atom to which each is bonded, a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, and the remaining R 22b represent a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group having 3 to 4 carbon atoms, or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof.

[0094] Among the above-mentioned component (F), an acrylic resin (F3) is preferably used.

[0095] In addition, the weight-average molecular weight of the polystyrene conversion of the component (F) is preferably 10,000 to 600,000, more preferably 50,000 to 600,000, and further preferably 230,000 to 550,000. By being such a weight-average molecular weight, the resin physical properties of the resist are excellent.

[0096] Further, the component (F) is preferably a resin having a dispersity of 1.05 or more. Here, the "dispersity" is a value obtained by dividing the weight-average molecular weight by the number-average molecular weight. By being such a dispersity, the plating resistance and the resin physical properties of the resist are excellent.

[0097] In the solid component of the chemically amplified positive photoresist composition, the content of the above-mentioned component (F) is preferably 5 to 60% by weight.

[0098] <Alkali-soluble resin (G)>

[0099] In the chemical amplification positive photoresist composition of the present application, in order to improve the resin properties of the resist, it is preferable to further contain an alkali-soluble resin (hereinafter referred to as "component (G)"). As the component (G), at least one selected from the group consisting of novolak resin, polyhydroxystyrene resin, acrylic resin, and polyvinyl resin is preferable.

[0100] The content of the component (G) is preferably 5 to 95 parts by weight, more preferably 10 to 90 parts by weight, relative to 100 parts by weight of the component (F) described above. By being 5 parts by weight or more, the resin properties of the resist can be improved, and by being 95 parts by weight or less, there is a tendency to be able to prevent film reduction at the time of development.

[0101] <Acid diffusion control agent (H)>

[0102] In the chemical amplification positive photoresist composition of the present application, in order to improve the resist pattern shape, post-exposure delay stability, and the like, it is preferable to further contain an acid diffusion control agent (H) (hereinafter referred to as "component (H)"). As the component (H), a nitrogen-containing compound is preferable, and an organic carboxylic acid or an oxygen-containing acid of phosphorus or a derivative thereof can be further contained as needed.

[0103] In addition, in the chemical amplification positive photoresist composition of the present application, in order to improve the adhesion to the substrate, an adhesion aid can also be further contained. As the adhesion aid used, a functional silane coupling agent is preferable.

[0104] In addition, in the chemical amplification positive photoresist composition of the present application, in order to improve the coatability, defoaming property, leveling property, and the like, a surfactant can also be further contained.

[0105] In addition, in the chemical amplification positive photoresist composition of the present application, in order to make fine adjustments to the solubility to the alkali developer, an acid, an acid anhydride, or a high-boiling solvent can also be further contained.

[0106] In addition, in the chemical amplification positive photoresist composition of the present application, a sensitizer is not essentially required, but a sensitizer can be contained as a component for supplementing the sensitivity as needed. As such a sensitizer, a conventionally known sensitizer can be used, and specifically, the above-described sensitizer can be mentioned.

[0107] The amount of these sensitizers is 5 to 500 parts by weight, preferably 10 to 300 parts by weight, relative to 100 parts by weight of the total weight of the onium salt represented by the above formula (1).

[0108] In addition, in the chemical amplification positive photoresist composition of the present application, an organic solvent can be appropriately mixed in order to adjust the viscosity. As specific examples of the organic solvent, the above-mentioned organic solvents can be given.

[0109] The amount of use of these organic solvents is preferably in the range of 30% by weight or more of the solid content concentration so that the film thickness of the photoresist layer obtained by using the chemical amplification positive photoresist composition (for example, spin coating method) is 5 μm or more.

[0110] As for the preparation of the chemical amplification positive photoresist composition for thick film, for example, not only the above-mentioned components can be mixed and stirred by the usual method, but also a disperser, homogenizer, three-roll mill or the like can be used for dispersion and mixing as needed. In addition, further filtration using a screen, membrane filter or the like can be performed after mixing.

[0111] The chemical amplification positive photoresist composition of the present application is suitable for forming a photoresist layer having a film thickness of usually 5 to 150 μm, more preferably 10 to 120 μm, further preferably 10 to 100 μm on a support. The photoresist layer build-up is a build-up in which a photoresist layer composed of the chemical amplification positive photoresist composition of the present application is layered on a support.

[0112] As the support, there is no particular limitation, and a conventionally known support can be used, and examples thereof can include, for example, an electronic component substrate, a substrate on which a prescribed wiring pattern is formed, and the like. As the substrate, for example, a substrate made of a metal such as silicon, silicon nitride, titanium, tantalum, palladium, titanium tungsten, copper, chromium, iron, aluminum, and the like, a glass substrate, and the like can be given. In particular, the chemical amplification positive photoresist composition of the present application can form a resist pattern on a copper substrate as well. As the material of the wiring pattern, for example, copper, solder, chromium, aluminum, nickel, gold, and the like are used.

[0113] The above-mentioned photoresist layer build-up can be manufactured, for example, as follows. That is, a solution of the chemical amplification positive photoresist composition prepared as above is applied to a support, and the solvent is removed by heating, whereby a desired coating film is formed. As the method of applying to the support, a spin coating method, a slit coating method, a roll coating method, a screen printing method, an applicator method, and the like can be used. The pre-baking conditions of the coating film of the composition of the present application vary depending on the kind of each component in the composition, the mixing ratio, the coating film thickness, and the like, and are usually performed at 70 to 150°C, preferably at 80 to 140°C for about 2 to 60 minutes.

[0114] 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.

[0115] In order to form a resist pattern using the photoresist layer stack obtained as above, the obtained photoresist layer is subjected to irradiation (exposure) of light or a radiation ray, such as ultraviolet rays or visible light having a wavelength of 300 to 500 nm, in a site-selective manner through a mask having a prescribed pattern.

[0116] Here, "light" is light that activates a photoacid generator to generate an acid, and includes ultraviolet rays, visible light, far ultraviolet rays, and the like. In addition, "radiation ray" refers to X-rays, electron rays, ion beams, and the like. As a light or radiation ray source, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, an argon laser, an LED lamp, and the like can be used. In addition, the radiation ray irradiation amount differs depending on the type, mixing amount, and the like of each component in the composition, the film thickness of the coating film, and the like, and, for example, in the case of using an ultrahigh-pressure mercury lamp, is 50 to 10,000 mJ / cm 2 .

[0117] Then, after exposure, the acid diffusion is promoted by heating using a known method, and the alkali-solubility of the photoresist layer of the exposed portion is changed. Subsequently, for example, using a prescribed aqueous alkali solution as a developer, the unnecessary portion is dissolved and removed to obtain a prescribed resist pattern.

[0118] The development time differs depending on the type, mixing ratio, and the like of each component of the composition, and the dry film thickness of the composition, and is usually 1 to 30 minutes. In addition, the development method can be any one of a puddle method, an immersion method, a dip method, a spray development method, and the like. After development, a running water rinse is performed for 30 to 90 seconds, and drying is performed using an air gun, an oven, or the like.

[0119] In the non-resist portion (portion removed by the alkali developer) of the resist pattern thus obtained, a conductor such as a metal can be embedded by plating or the like, and a connection terminal such as a metal pillar or a bump can be formed. Note that the plating treatment method is not particularly limited, and various known methods can be used. As a plating solution, a solder plating solution, a copper plating solution, a gold plating solution, or a nickel plating solution is particularly preferred. The remaining resist pattern is finally removed using a peeling solution or the like in accordance with a conventional method.

[0120] The chemically amplified positive photoresist composition of the present invention can also be used as a dry film. This dry film is a dry film in which protective films are formed on both sides of a layer composed of the chemically amplified positive photoresist composition of the present invention. The film thickness of the layer composed of the chemically amplified positive photoresist composition is generally in the range of 10 to 150 μm, preferably 20 to 120 μm, and more preferably 20 to 80 μm. In addition, the protective film is not particularly limited, and a resin film conventionally used for dry films can be used. As an example, one can be a polyethylene terephthalate film and the other can be one selected from the group consisting of polyethylene terephthalate films, polypropylene films, and polyethylene films.

[0121] The chemically amplified positive dry film described above can be produced, for example, by applying a solution of the chemically amplified positive photoresist composition prepared above onto a protective film and removing the solvent by heating to form the desired coating film. Drying conditions vary depending on the types and proportions of the components in the composition, the coating film thickness, and other factors, but are generally 60-100°C for approximately 5-20 minutes.

[0122] To form a resist pattern using the chemically amplified dry film obtained above, one protective film of the chemically amplified positive dry film is peeled off, and the film is laminated onto the support with the exposed surface facing the support to obtain a photoresist layer. The resist is then pre-baked to dry, and the other protective film is then peeled off.

[0123] On the photoresist layer obtained on the support as described above, a resist pattern can be formed by the same method as that described for the photoresist layer formed by direct coating on the support.

[0124] Next, in the chemically amplified negative photoresist composition of (3), the onium salt (A) of the present invention, which is a compound that generates an acid upon irradiation with light or radiation, functions as an acid generator, and the chemically amplified negative photoresist composition contains an alkali-soluble resin (I) having a phenolic hydroxyl group under the action of the acid, and a crosslinking agent (J).

[0125] Alkali-soluble resin having phenolic hydroxyl groups (I)

[0126] As the "alkali-soluble resin having a phenolic hydroxyl group" in the present application (hereinafter referred to as "phenolic resin (I)"), for example, a novolak resin, a polyhydroxystyrene, a copolymer of polyhydroxystyrene, a copolymer of hydroxystyrene and styrene, a copolymer of hydroxystyrene and styrene and a (meth) acrylic acid derivative, a phenol-xylylene glycol condensation resin, a cresol-xylylene glycol condensation resin, a phenol-dicyclopentadiene condensation resin, and the like are used. Among these, a novolak resin, a polyhydroxystyrene, a copolymer of polyhydroxystyrene, a copolymer of hydroxystyrene and styrene, a copolymer of hydroxystyrene and styrene and a (meth) acrylic acid derivative, a phenol-xylylene glycol condensation resin are preferred. Note that these phenolic resins (I) can be used singly or two or more kinds can be used in combination.

[0127] In addition, the above-mentioned phenolic resin (I) can also contain a phenolic low molecular compound as a part of the components.

[0128] As the above-mentioned phenolic low molecular compound, for example, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, and the like can be mentioned.

[0129] Crosslinking agent (J)

[0130] The "crosslinking agent" in the present application (hereinafter also referred to as "crosslinking agent (J)") is not particularly limited as long as it functions as a crosslinking component (curing component) which reacts with the above-mentioned phenolic resin (I). As the above-mentioned crosslinking agent (J), for example, a compound having at least two or more alkyl-etherified amines in the molecule, a compound having at least two or more alkyl-etherified benzene as a skeleton in the molecule, a compound containing an oxirane ring, a compound containing an episulfide ring, a compound containing an oxetanyl group, a compound containing an isocyanate group (including blocked compounds), and the like can be mentioned.

[0131] Among these crosslinking agents (J), a compound having at least two or more alkyl-etherified amines in the molecule and a compound containing an oxirane ring are preferred. Further, a compound having at least two or more alkyl-etherified amines in the molecule and a compound containing an oxirane ring are more preferably used in combination.

[0132] The compounding amount of the crosslinking agent (J) in the present application is preferably 1 to 100 parts by weight, more preferably 5 to 50 parts by weight, relative to 100 parts by weight of the above-mentioned phenolic resin (I). In the case where the compounding amount of the crosslinking agent (J) is 1 to 100 parts by weight, the curing reaction sufficiently proceeds, and the obtained cured product has a good pattern shape at a high resolution, and is excellent in heat resistance and electric insulation, and thus is preferred.

[0133] In addition, when the compound having an alkyl-etherified amino group and the compound containing an oxirane ring are used in combination, the content ratio of the compound containing an oxirane ring is preferably 50% by weight or less, more preferably 5 to 40% by weight, and particularly preferably 5 to 30% by weight, based on 100% by weight of the total of the compound having an alkyl-etherified amino group and the compound containing an oxirane ring.

[0134] In this case, the obtained cured film is excellent in resolution and chemical resistance, and is therefore preferred.

[0135] Crosslinking microparticles (K)

[0136] In the chemically amplified negative photoresist composition of the present application, crosslinking microparticles (hereinafter also referred to as "crosslinking microparticles (K)") can be further contained in order to improve the durability and thermal shock resistance of the obtained cured product.

[0137] The average particle diameter of the crosslinking microparticles (K) is usually 30 to 500 nm, preferably 40 to 200 nm, and further preferably 50 to 120 nm.

[0138] The method for controlling the particle diameter of the crosslinking microparticles (K) is not particularly limited, and for example, in the case where the crosslinking microparticles are synthesized by emulsion polymerization, the number of micelles in the emulsion polymerization can be controlled by the amount of emulsifier used, thereby controlling the particle diameter.

[0139] Note that the average particle diameter of the crosslinking microparticles (K) is a value measured by diluting a dispersion liquid of the crosslinking microparticles in accordance with a conventional method using a light scattering flow distribution measuring device or the like.

[0140] The blending amount of the crosslinking microparticles (K) is preferably 0.5 to 50 parts by weight, and more preferably 1 to 30 parts by weight, relative to 100 parts by weight of the above-described phenol-aldehyde resin (I). In the case where the blending amount of the crosslinking microparticles (K) 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.

[0141] Adhesion aid

[0142] In addition, in the chemically amplified negative photoresist composition of the present application, an adhesion aid can be contained in order to improve the adhesion to a substrate.

[0143] As the above-described adhesion aid, a functional silane coupling agent having a reactive substituent group such as a carboxyl group, a methacryloyl group, an isocyanate group, an epoxy group, or the like can be mentioned.

[0144] The blending amount of the adhesion aid is preferably 0.2 to 10 parts by weight, more preferably 0.5 to 8 parts by weight, relative to 100 parts by weight of the phenol resin (I) described above. In the case where the blending amount of the adhesion aid is 0.2 to 10 parts by weight, the storage stability is excellent, and good adhesion can be obtained, and thus is preferred.

[0145] Solvent

[0146] In addition, in the chemically amplified negative photoresist composition of the present application, a solvent can be contained in order to improve the handling property of the resin composition or adjust the viscosity, storage stability.

[0147] The solvent described above is not particularly limited, and specific examples can be cited from the solvents described above.

[0148] In addition, in the chemically amplified negative photoresist composition of the present application, a sensitizer can be contained as necessary. As such a sensitizer, a publicly known sensitizer can be used, and specifically, the sensitizer described above can be cited.

[0149] The amount of these sensitizers is 5 to 500 parts by weight, preferably 10 to 300 parts by weight, relative to 100 parts by weight of the total amount of the sulfonium salts represented by the formula (1) described above.

[0150] Other additives

[0151] In addition, in the chemically amplified negative photoresist composition of the present application, other additives can be contained as necessary to the extent that the characteristics of the present application are not impaired. As such other additives, inorganic fillers, quenching agents, leveling agents, surfactants, and the like can be cited.

[0152] The method for producing the chemically amplified negative photoresist composition of the present application is not particularly limited, and can be produced by a publicly known method. In addition, it can also be produced by stirring a sample bottle in which each component is contained and which is completely filled on a wave rotor.

[0153] The cured product in the present application is characterized in that it is cured from the chemically amplified negative photoresist composition described above.

[0154] The chemically amplified negative photoresist composition of the present application described above has a high residual film rate, excellent resolution, and the cured product thereof is excellent in electrical insulation, thermal shock resistance, and the like, and thus the cured product thereof can be suitably used as a surface protective film, a planarization film, an interlayer insulating film material, and the like for electronic parts such as semiconductor elements, semiconductor packages, and the like.

[0155] To form the cured product of the present application, the above-mentioned chemical amplification type negative photoresist composition of the present application is first applied to a support (resin-coated copper foil, copper-clad laminate, or a silicon wafer or alumina substrate with a metal sputtered film, etc.), and dried to form a coating film by volatilizing the solvent, etc. Then, exposure is performed through a desired mask pattern, and a heating treatment (hereinafter referred to as "PEB") is performed to promote the reaction of the phenol resin (F) with the crosslinking agent (G). Next, development is performed using an alkaline developer to dissolve and remove the unexposed portions, whereby the desired pattern can be obtained. Further, a heating treatment is performed to exhibit the insulating film properties, whereby a cured film can be obtained.

[0156] As the method of applying the resin composition to the support, a coating method such as dipping, spraying, bar coating, roll coating, or spin coating, etc. can be used. In addition, the thickness of the coating film can be appropriately controlled by adjusting the coating means, the solid content concentration of the composition solution, the viscosity, etc.

[0157] As the radiation used in the exposure, ultraviolet rays, electron rays, laser light, etc. such as a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a g-ray stepper, an h-ray stepper, an i-ray stepper, a gh-ray stepper, a ghi-ray stepper, etc. can be used. In addition, as the exposure amount, appropriate selection is made depending on the light source used, the resin film thickness, etc., and for example, in the case of irradiating ultraviolet rays from a high-pressure mercury lamp, the exposure amount is 100 to 50,000 J / m2when the resin film thickness is 1 to 50 μm. 2 left and right.

[0158] After the exposure, the above-mentioned PEB treatment is performed to promote the curing reaction of the phenol resin (F) with the crosslinking agent (G) caused by the generated acid. The PEB conditions differ depending on the compounding amount of the resin composition, the film thickness used, etc., and are usually performed at 70 to 150°C, preferably at 80 to 120°C, for 1 to 60 minutes or so. Then, development is performed using an alkaline developer to dissolve and remove the unexposed portions, whereby the desired pattern is formed. As the development method at this time, a spray development method, a spray development method, a dip development method, an immersion development method, etc. can be used. As the development conditions, 20 to 40°C for 1 to 10 minutes or so are usually used.

[0159] Further, in order to sufficiently exhibit the characteristics as an insulating film after development, it is possible to sufficiently cure it by performing a heat treatment. The curing conditions are not particularly limited, and the composition can be cured by heating at a temperature of 50 to 250°C for 30 minutes to 10 hours or so according to the use of the cured product. Alternatively, in order to sufficiently perform the curing or prevent deformation of the obtained pattern shape, it is also possible to perform the heating in two stages, for example, it is also possible to heat at a temperature of 50 to 120°C for 5 minutes to 2 hours or so in the first stage, and further heat at a temperature of 80 to 250°C for 10 minutes to 10 hours or so to cure it. If it is such a curing condition, as the heating equipment, a general oven or an infrared furnace or the like can be used.

[0160] Examples

[0161] Hereinafter, the present application will be specifically described by citing examples and comparative examples, but the present application is not limited thereto. Note that the parts in each example indicate parts by weight.

[0162] Production Example of Anion (B1) to (B6), (B'1)

[0163] Production Example of Anion (B1)

[0164] Potassium fluoride (KF) 4.44 g was slowly added to dimethoxyethane 50.0 g under cooling, and then tris(pentafluoroethyl)difluorophosphorane 32.5 g was put in under stirring. It was reacted by slowly putting while cooling so that the temperature would be 30°C or less, and a solution of potassium tris(pentafluoroethyl)trifluorophosphonate (K[(C2F5)3(F)3P]) was obtained. As a result of F-NMR, the ratio of the facial isomer was 0.0% by weight in the two isomers. + [(C2F5)3(F)3P] -

[0165] Production Example of Anion (B2)

[0166] Potassium fluoride (KF) 4.44 g was slowly added to dimethoxyethane 50.0 g under cooling, and then tris(pentafluoroethyl)difluorophosphorane 32.5 g was put in under stirring. It was reacted by slowly putting while cooling so that the temperature would be 30°C or less, and a solution of potassium tris(pentafluoroethyl)trifluorophosphonate (K[(C2F5)3(F)3P]) was obtained. As a result of F-NMR, the ratio of the facial isomer was 0.0% by weight in the two isomers. + [(C3F7)3(F)3P] -

[0167] Production Example of Anion (B3)

[0168] ​​A 40% aqueous hydrofluoric acid solution 7.04 g was diluted with 19.0 g of ion exchange water, and after being cooled to 5°C or lower, tri(pentafluoroethyl)difluorophosphorane 60.0 g was slowly added with stirring. The reaction was carried out by slowly adding while cooling to 10°C or lower. After that, potassium hydroxide 7.90 g was dissolved in advance in ion exchange water 30 g and added to obtain a solution of potassium tri(heptafluoropropyl)trifluorophosphonate (K + [(C2F5)3(F)3P] - ). As a result of F-NMR, the ratio of the facial isomer was 0.1% by weight in the two isomers.

[0169] Production Example of Anion (B4)

[0170] A 40% aqueous hydrofluoric acid solution 5.65 g was diluted with 6.73 g of ion exchange water, and after being cooled to 5°C or lower, tri(pentafluoroethyl)difluorophosphorane 47.8 g was slowly added with stirring. The reaction was carried out by slowly adding while cooling to 10°C or lower. After that, potassium hydroxide 6.29 g was dissolved in advance in ion exchange water 30 g and added to obtain a solution of potassium tri(heptafluoropropyl)trifluorophosphonate (K + [(C2F5)3(F)3P] - ). As a result of F-NMR, the ratio of the facial isomer was 5.0% by weight in the two isomers.

[0171] Production Example of Anion (B5)

[0172] Hydrogen fluoride (HF) 1.66 g was slowly added to diethyl ether 11.0 g with cooling, and after that, tri(pentafluoroethyl)difluorophosphorane 33.6 g was slowly added with stirring. The reaction was carried out by slowly adding while cooling to 5°C or lower. After that, potassium hydroxide 4.42 g was added to obtain a solution of potassium tri(heptafluoropropyl)trifluorophosphonate (K + [(C2F5)3(F)3P] - ). As a result of F-NMR, the ratio of the facial isomer was 14.6% by weight in the two isomers.

[0173] Production Example of Anion (B6)

[0174] A 40% aqueous hydrofluoric acid solution 7.51 g was diluted with 10.0 g of ion exchange water, and after being cooled to 5°C or lower, tri(pentafluorophenyl)difluorophosphorane 63.6 g was slowly added with stirring. The reaction was carried out by slowly adding while cooling to 10°C or lower. After that, potassium hydroxide 8.36 g was dissolved in advance in ion exchange water 30 g and added to obtain a solution of potassium tri(pentafluorophenyl)trifluorophosphonate (K +[(C6F5)3(F)3P] - The results of F-NMR showed that the ratio of the face isomer among the two isomers was 5.0 wt%.

[0175] Production Example of Anion (B'1)

[0176] 1.64 g of hydrogen fluoride (HF) was slowly added to 6.00 g of methanol under cooling, and then 32.5 g of tris(pentafluoroethyl)difluorophosphorane was slowly added under stirring. The reaction was carried out while cooling so that the temperature was below 5°C. Then, 4.28 g of potassium hydroxide was added to obtain tris(heptafluoropropyl)trifluorophosphonic acid potassium salt (K + [(C2F5)3(F)3P] - The results of F-NMR showed that the proportion of the face-type isomer among the two isomers was 18.4% by weight.

[0177] Examples of Onium Salts (A1-1)

[0178] Preparation of 4-(phenylthio)phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphonate (anion face form: 0.0 wt%)

[0179] After uniformly mixing 12.12 g of diphenyl sulfoxide, 9.3 g of diphenyl sulfide, and 43.0 g of methanesulfonic acid, 7.9 g of acetic anhydride was added dropwise. After reacting at 50°C for 5 hours, the mixture was cooled to room temperature. To the reaction solution, 124.5 g of anion (B1) prepared as a 20% aqueous solution or solvent-substituted solution was added dropwise, followed by stirring for 2 hours. The precipitated oily component was extracted into 120 g of ethyl acetate, the aqueous layer was separated, and the organic layer was further washed three times. The solvent was removed from the organic layer, 50 g of toluene was added to dissolve the mixture, and 270 g of hexane was added and mixed. The mixture was then allowed to stand for 1 hour to separate into two layers. The upper layer was removed, and 150 g of hexane was added to the remaining lower layer, followed by thorough stirring to precipitate crystals. The crystals were filtered and dried under reduced pressure to obtain 4-(phenylthio)phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphonate (anion hexahydrate: 0.0 wt%) (A1-1). The chemical formula is shown below (a1).

[0180] [Chemistry 5]

[0181]

[0182] Examples of Onium Salts (A1-2) to (A1-6) and Comparative Example (A'1-1)

[0183] Instead of the anion (B1) of the production example of (Al-1), the anions (B2) to (B6) and the anion (B'1) were used respectively to obtain onium salts (Al-2) to (Al-6) and (Al-1-1). Note that the fraction of only the anion (B2) 20% aqueous solution was 167 g. The names of the synthesized compounds are described below respectively.

[0184] (A1-2): 4-(phenylthio)phenyldiphenylsulfonium · tris (heptafluoropropyl) trifluorophosphonate (0.0 wt% of the facial form of the anion)

[0185] (A1-3): 4-(phenylthio)phenyldiphenylsulfonium · tris (pentafluoroethyl) trifluorophosphonate (0.1 wt% of the facial form of the anion)

[0186] (A1-4): 4-(phenylthio)phenyldiphenylsulfonium · tris (pentafluoroethyl) trifluorophosphonate (5.0 wt% of the facial form of the anion)

[0187] (A1-5): 4-(phenylthio)phenyldiphenylsulfonium · tris (pentafluoroethyl) trifluorophosphonate (14.6 wt% of the facial form of the anion)

[0188] (A1-6): 4-(phenylthio)phenyldiphenylsulfonium · tris (pentafluoroethyl) trifluorophosphonate (5.0 wt% of the facial form of the anion)

[0189] (A'1-1): 4-(phenylthio)phenyldiphenylsulfonium · tris (pentafluoroethyl) trifluorophosphonate (18.4 wt% of the facial form of the anion)

[0190] Regarding the chemical formula, (Al-2) is (a2), (Al-3) to (Al-5) and (Al-1-1) are (al), and (Al-6) is (a3).

[0191] [Chemical 6]

[0192]

[0193] [Chemical 7]

[0194]

[0195] Example of onium salt (A2-1)

[0196] Production of (4-isopropylphenyl) tolyl iodonium · tris (pentafluoroethyl) trifluorophosphonate (0.0 wt% of the facial form of the anion)

[0197] To 4-methyl iodobenzene 20 g, acetic acid 50 g, sulfuric acid 10 g was added to dissolve, and while cooling in an ice water bath, potassium persulfate 10 g was added little by little at 15°C or lower. After 4 hours of reaction at 20°C, cumene 24.4 g was added dropwise to the solution at 20°C or lower. After 20 hours of reaction at room temperature, the reaction solution was poured into an aqueous solution 50 parts of anion (B1) of an equal molar amount. Further, the solution was stirred for 3 hours. To the solution, dichloromethane 500 parts was added. After standing, the aqueous layer was removed by liquid separation, and the organic layer was washed with water 100 parts 5 times. The dichloromethane was concentrated, and recrystallized from cyclohexane to obtain (4-isopropylphenyl)tolyl iodonium tris(pentafluoroethyl)trifluorophosphonate (anionic facial form: 0.0 wt%). The chemical formula is shown below in formula (a4).

[0198] [Chemical 8]

[0199]

[0200] Examples and Comparative Example (A'2-1) of onium salts (A2-2) to (A2-6)

[0201] Instead of the anion (B1) of the production example of (A2-1), anions (B2) to (B6) and anion (B'1) were used respectively to obtain onium salts (A2-2) to (A2-6) and (A'2-1). Note that the amount of anion (B2) 20% aqueous solution was 167 g. The names of the synthesized compounds are shown below respectively.

[0202] (A2-2): (4-isopropylphenyl)tolyl iodonium tris (heptafluoropropyl) trifluorophosphonate (anionic facial form: 0.0 wt%)

[0203] (A2-3): (4-isopropylphenyl)tolyl iodonium tris (pentafluoroethyl) trifluorophosphonate (anionic facial form: 0.1 wt%)

[0204] (A2-4): (4-isopropylphenyl)tolyl iodonium tris (pentafluoroethyl) trifluorophosphonate (anionic facial form: 5.0 wt%)

[0205] (A2-5): (4-isopropylphenyl)tolyl iodonium tris (pentafluoroethyl) trifluorophosphonate (anionic facial form: 14.6 wt%)

[0206] (A2-6): (4-isopropylphenyl)tolyl iodonium tris (pentafluorophenyl) trifluorophosphonate (anionic facial form: 5.0 wt%)

[0207] (A'2-1): (4-isopropylphenyl)tolyl iodonium tris (pentafluoroethyl) trifluorophosphonate (anionic facial form: 18.4 wt%)

[0208] As to the chemical formula, (A2-2) is (a5), (A2-3) to (A2-5) and (A'2-1) are (a4), and (A2-6) is (a6).

[0209] [Chemical 9]

[0210]

[0211] [Chemical 10]

[0212]

[0213] Examples of onium salt (A3-1)

[0214] Production of [4-(4-biphenylthio)phenyl]-4-biphenylylphenyl sulfonium tris(pentafluoroethyl)trifluorophosphonate (facial form of anion: 0.0 wt%)

[0215] A mixture of 4-[(phenyl)sulfinyl]biphenyl 11g, 4-(phenylthio)biphenyl 12g, acetic anhydride 22g and methanesulfonic acid 16 parts was uniformly mixed and reacted at 65°C for 3 hours. The reaction solution was cooled to room temperature, poured into ion exchange water 100 mL, extracted with dichloromethane 100g, and washed with water until the pH of the aqueous layer became neutral. The dichloromethane layer was distilled to remove the solvent in a rotary evaporator, thereby obtaining a brown solid. This was washed with ethyl acetate / hexane, and the organic solvent was concentrated, thereby obtaining an intermediate.

[0216] The intermediate 6.2g was dissolved in dichloromethane 60 mL, and an aqueous solution 70g containing anion (B1) was mixed at room temperature. This was stirred for 3 hours in this state, and the dichloromethane layer was washed with water 5 times by liquid separation, and then distilled to remove the solvent in a rotary evaporator, thereby obtaining [4-(4-biphenylthio)phenyl]-4-biphenylylphenyl sulfonium tris(pentafluoroethyl)trifluorophosphonate (facial form of anion: 5.0 wt%). The chemical formula is shown in the following formula (a7).

[0217] [Chemical 11]

[0218]

[0219] Examples and comparative example (A'3-1) of onium salts (A3-2) to (A3-6)

[0220] Instead of the anion (B1) of the production example of (A3-1), anions (B2) to (B6) and anion (B'1) were used respectively, to obtain onium salts (A3-2) to (A3-6) and (A'3-1). Note that only the fraction of a 20% aqueous solution of anion (B2) was 167g. The names of the synthesized compounds are as follows.

[0221] (A3-2): [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium · tris (heptafluoropropyl)trifluorophosphonate (0.0 wt% of the facial form of the anion)

[0222] (A3-3): [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium · tris (pentafluoroethyl)trifluorophosphonate (0.1 wt% of the facial form of the anion)

[0223] (A3-4): [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium · tris (pentafluoroethyl)trifluorophosphonate (5.0 wt% of the facial form of the anion)

[0224] (A3-5): [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium · tris (pentafluoroethyl)trifluorophosphonate (14.6 wt% of the facial form of the anion)

[0225] (A3-6): [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium · tris (pentafluorophenyl)trifluorophosphonate (5.0 wt% of the facial form of the anion)

[0226] (A'3-1): [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium · tris (pentafluoroethyl)trifluorophosphonate (18.4 wt% of the facial form of the anion)

[0227] As to the chemical formula, (A3-2) is (a8), (A3-3) to (A3-5) and (A'3-1) are (a7), and (A3-6) is (a9).

[0228] [Chemical 12]

[0229]

[0230] [Chemical 13]

[0231]

[0232] Examples of onium salt (A4-1)

[0233] Production of [4-(4-acetylphenylthio)phenyl]diphenylsulfonium · tris (pentafluoroethyl)trifluorophosphonate (0.0 wt% of the facial form of the anion)

[0234] A solution of 32 parts of (4-phenylthio)phenyldiphenylsulfonium triflate in 89 parts of dichloromethane was added dropwise to a suspension of 36 parts of aluminum chloride, 12 parts of acetyl chloride, and 200 parts of dichloromethane, with stirring and cooling to maintain the temperature of the system below 10°C. After the addition, the mixture was stirred for 2 hours at room temperature, and then 300 parts of cold water was added. The upper layer was removed, and the dichloromethane layer was washed with ion exchange water until the pH reached neutrality. Next, an aqueous solution of anion (B1) 70 g was mixed at room temperature, and the mixture was stirred for 3 hours in this state. The dichloromethane layer was washed with water 5 times by liquid separation, and then distilled to remove the solvent in a rotary evaporator, thereby obtaining [4-(4-acetylphenylthio)]phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphate (anionic facial form: 0.0 wt%). The chemical formula is shown in the following formula (a10).

[0235] [Chemical 14]

[0236]

[0237] Examples and Comparative Example (A'4-1) of onium salts (A4-2) to (A4-6)

[0238] Instead of the anion (B1) of the production example of (A4-1), the anions (B2) to (B6) and the anion (B'1) were used respectively, to obtain onium salts (A4-2) to (A4-6) and (A'4-1). Note that the fraction of only the anion (B2) 20% aqueous solution was 167 g. The names of the synthesized compounds are described below respectively.

[0239] (A4-2): [4-(4-acetylphenylthio)]phenyldiphenylsulfonium tris(heptafluoropropyl)trifluorophosphate (anionic facial form: 0.0 wt%)

[0240] (A4-3): [4-(4-acetylphenylthio)]phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphate (anionic facial form: 0.1 wt%)

[0241] (A4-4): [4-(4-acetylphenylthio)]phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphate (anionic facial form: 5.0 wt%)

[0242] (A4-5): [4-(4-acetylphenylthio)]phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphate (anionic facial form: 14.6 wt%)

[0243] (A4-6): [4-(4-acetylphenylthio)]phenyldiphenylsulfonium tris(pentafluorophenyl)trifluorophosphate (anionic facial form: 5.0 wt%)

[0244] (A'4-1): [4-(4-acetylphenylsulfanyl)]phenyldiphenylsulfonium · tris(pentafluoroethyl)trifluorophosphonate (a facial form of anion: 18.4% by weight)

[0245] As to the chemical formula, (A4-2) is (al l), (A4-3) to (A4-5) and (A'4-1) are (alO), and (A4-6) is (a 12).

[0246] [Chemical 15]

[0247]

[0248] [Chemical 16]

[0249]

[0250] Examples of onium salt (A5-1)

[0251] Production of fluorene skeleton sulfonium · tris(pentafluoroethyl)trifluorophosphonate (a facial form of anion: 0.0% by weight)

[0252] Into 2-[(phenyl)sulfinyl]-9,9-dimethylfluorene 1.0 part and 2-(phenylsulfanyl)-9,9-dimethylfluorene 1.1 part, acetic anhydride 2.0 parts and methanesulfonic acid 1.6 parts, stirring was performed at 65°C for 3 hours. The reaction solution was cooled to room temperature, and was put into ion exchange water 5.0 parts, extraction was performed with dichloromethane 5.0 parts, and washing with ion exchange water was performed until the pH of the aqueous layer became neutral. Subsequently, the aqueous solution 70 g containing anion (Bl) was mixed into the dichloromethane layer at room temperature with stirring for 3 hours, and after the dichloromethane layer was washed with water 5 times by a liquid separation operation, it was moved to a rotary evaporator to distill off the solvent, whereby [4-(4-acetylphenylsulfanyl)]phenyldiphenylsulfonium · tris(pentafluoroethyl)trifluorophosphonate (a facial form of anion: 0.0% by weight) was obtained. The chemical formula is shown by the following formula (al3).

[0253] [Chemical 17]

[0254]

[0255] Examples and comparative example (A'5-1) of onium salts (A5-2) to (A5-6)

[0256] Instead of the anion (Bl) of the production example of (A5-1), the anions (B2) to (B6) and the anion (B'1) were used respectively, and onium salts (A5-2) to (A5-6) and (A'5-1) were obtained. Note that the fraction of only the anion (B2) 20% aqueous solution was 167 g. The synthesized compounds are described below respectively.

[0257] (A5-2): fluorene skeleton sulfonium · tri(septylfluoropropyl) trifluorophosphonium salt (planar form of anion: 0.0 wt%)

[0258] (A5-3): fluorene skeleton sulfonium · tri(pentafluoroethyl) trifluorophosphonium salt (planar form of anion: 0.1 wt%)

[0259] (A5-4): fluorene skeleton sulfonium · tri(pentafluoroethyl) trifluorophosphonium salt (planar form of anion: 5.0 wt%)

[0260] (A5-5): fluorene skeleton sulfonium · tri(pentafluoroethyl) trifluorophosphonium salt (planar form of anion: 14.6 wt%)

[0261] (A5-6): fluorene skeleton sulfonium · tri(pentafluorophenyl) trifluorophosphonium salt (planar form of anion: 5.0 wt%)

[0262] (A'5-1): fluorene skeleton sulfonium · tri(pentafluoroethyl) trifluorophosphonium salt (planar form of anion: 18.4 wt%)

[0263] As to the chemical formula, (A5-2) is (a14), (A5-3) to (A5-5) and (A'5-1) are (a13), and (A5-6) is (a15).

[0264] [Chemical 18]

[0265]

[0266] [Chemical 19]

[0267]

[0268] [Chemical Amplification Positive Resist Composition]

[0269] Preparation of Evaluation Test Sample

[0270] As shown in Table 1, onium salts (Al-1) to (Al-6), (A2-1) to (A2-6), (A3-1) to (A3-6), (A4-1) to (A4-6) and (A5-1) to (A-6) of the present application as a photo-acid generator, 40 parts by weight of a resin represented by the following formula (Resin-1) as a resin component (F), and m-cresol and p-cresol as a resin component (G) were subjected to addition condensation in the presence of formaldehyde and an acid catalyst, and 60 parts by weight of the obtained novolak resin was uniformly dissolved in a solvent (propylene glycol monomethyl ether acetate), filtered through a membrane filter having a pore size of 1 μm, to prepare a chemically amplified positive photoresist composition having a solid content concentration of 40% by weight (Examples P1 to P30). In addition, Comparative Examples were also prepared in the same manner using the mixing amounts shown in Table 1 to prepare chemically amplified positive photoresist compositions (Comparative Examples P'1 to P'5).

[0271] [Table 1]

[0272]

[0273] [Chemical Formula 20]

[0274]

[0275] [Sensitivity Evaluation]

[0276] After the positive resist compositions prepared in the above Examples P1 to P30 and Comparative Examples P'1 to P'5 were spin-coated onto a silicon wafer substrate, drying was performed to obtain a photoresist layer having a film thickness of about 20 μm. The resist layer was pre-baked at 130°C for 6 minutes using a hot plate. After pre-baking, pattern exposure (i-ray) was performed using a 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 the dipping method using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide, rinsed with running water, and purged with nitrogen gas to obtain a 10 μm line-space (L&S) pattern. Further, the minimum exposure amount (below which no residue of the pattern was confirmed) required for forming the resist pattern, i.e., the minimum necessary exposure amount (corresponding to sensitivity) was measured.

[0277] [Pattern Shape Evaluation]

[0278] The lower edge dimension La and the upper edge dimension Lb of the shape cross section of the 10 μm L&S pattern formed on the silicon wafer substrate by the above operation were measured using a scanning electron microscope, and the pattern shape was judged according to the following criteria. The results are shown in Table 2.

[0279] ◎: 0.90 ≤ Lb / La ≤ 1

[0280] O: 0.85 < Lb / La < 0.90

[0281] X: Lb / La < 0.85

[0282] [Table 2]

[0283]

[0284] As shown in Table 2, it is known that the chemical amplification positive photoresist compositions of Examples P1 to P30 require a lower minimum exposure amount than the comparative examples P'1 to P'5, that is, the photoacid generators of the present application have higher sensitivity and superior pattern shape than the comparative photoacid generators.

[0285] [Chemical amplification negative photoresist composition evaluation]

[0286] [Preparation of evaluation samples]

[0287] As shown in Table 3, 1 part by weight of the onium salt (A1-1) to (A1-6), (A2-1) to (A2-6), (A3-1) to (A3-6), (A4-1) to (A4-6), and (A5-1) to (A-6) of the present application as a photoacid generator, 100 parts by weight of a copolymer (Mw = 10,000) consisting of p-hydroxystyrene / styrene = 80 / 20 (molar ratio) as component (I) of a phenol novolak resin, 20 parts by weight of hexamethoxymethyl melamine (manufactured by Sanwa Chemical Co., trade name "Nikalac MW-390") as component (J) of a crosslinking agent, 10 parts by weight of a copolymer consisting of butadiene / acrylonitrile / hydroxybutyl methacrylate / methacrylic acid / divinylbenzene = 64 / 20 / 8 / 6 / 2 (wt%) (average particle diameter = 65 nm, Tg = -38°C) as component (K) of a crosslinking fine particle, and 5 parts by weight of γ-glycidoxypropyltrimethoxysilane (manufactured by Chisso Co., trade name "S510") as an adhesion aid were uniformly dissolved in 150 parts by weight of a solvent (ethyl lactate) to prepare the chemical amplification negative photoresist compositions of the present application (Examples N1 to N30). In addition, the comparative examples were also prepared in the same manner using the mixing amounts shown in Table 3 to prepare the chemical amplification negative photoresist compositions (Comparative Examples N'1 to N'5).

[0288] [Table 3]

[0289]

[0290] [Sensitivity evaluation]

[0291] After spin-coating each composition onto a silicon wafer substrate, a hot plate was used to heat-dry at 110°C for 3 minutes to obtain a resin coating film having a film thickness of about 20 μm. Then, pattern exposure (i-ray) was performed using a TME-150RSC (manufactured by Topcon Corporation), and post-exposure baking (PEB) was performed using a hot plate at 110°C for 3 minutes. Then, a development treatment was performed by immersion in a 2.38 wt% aqueous solution of tetramethylammonium hydroxide for 2 minutes, rinsed with running water, and purged with nitrogen to obtain a line-space pattern of 10 μm. Further, the minimum necessary exposure amount (corresponding to sensitivity) required to form a pattern having a residual film ratio (indicating the proportion of residual film before and after development) of 95% or more was measured.

[0292] [Pattern shape evaluation]

[0293] The lower edge dimension La and the upper edge dimension Lb of the shape cross-section of the 20 μm L&S pattern formed on the silicon wafer substrate by the above operation were measured using a scanning electron microscope, and the pattern shape was judged according to the following criteria. The results are shown in Table 4.

[0294] ◎: 0.90 < La / Lb < 1

[0295] O: 0.85 < La / Lb < 0.90

[0296] X: La / Lb < 0.85

[0297] [Table 4]

[0298]

[0299] As shown in Table 4, the chemically amplified positive photoresist composition of Examples N1 to N30 required a lower minimum exposure amount than the comparative examples N'1 to N'5, i.e., the photoacid generator of the present application had higher sensitivity than the comparative photoacid generators, and the pattern shape was excellent.

[0300] Industrial applicability

[0301] The chemically amplified positive photoresist composition and the chemically amplified negative photoresist composition using the onium salt-containing photoacid generator of the present application can obtain a high-sensitivity resist (a pattern can be formed at a lower exposure amount than in the past). Furthermore, the chemically amplified positive photoresist composition and the chemically amplified negative photoresist composition of the present application can form a good resist pattern shape.

Claims

1. An onium salt represented by the general formula (1) or any one of the following formulas (a3) ​​to (a15), wherein: Of the two isomers of the anion structure, the facile isomer and the meridian isomer, the proportion of the facile isomer is 15.0% by weight or less. [(R 2 ) n+1 -E] + [(R 1 )3(F)3P] - (1) In formula (1), R 1 is pentafluoroethyl, heptafluoro-n-propyl, nonafluoro-n-butyl, heptafluoro-isopropyl or trifluoromethyl; E is I or S; when E is I, n is 1, when E is S, n is 2; R 2 is an organic group bonded to E, the organic group is a phenyl group or a fluorenyl group which may have a substituent, the substituent is a phenylthio group or a biphenylthio group, R 2 The number of R is n+1, (n+1) 2 Each is the same as or different from each other, (a3) 4-(phenylthio)phenyldiphenylsulfonium tris(pentafluorophenyl)trifluorophosphonate, (a4) (4-isopropylphenyl)tolyliodonium tris(pentafluoroethyl) trifluorophosphonate, (a5) (4-isopropylphenyl)tolyliodonium tris(heptafluoropropyl)trifluorophosphonate, (a6) (4-isopropylphenyl)tolyliodonium tris(pentafluorophenyl) trifluorophosphonate, (a7) [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium tris(pentafluoroethyl)trifluorophosphonate, (a8) [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium tris(heptafluoropropyl)trifluorophosphonate, (a9) [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium tris(pentafluorophenyl)trifluorophosphonate, (a10) [4-(4-Acetylphenylthio)]phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphonate, (a11) [4-(4-acetylphenylthio)]phenyldiphenylsulfonium tris(heptafluoropropyl)trifluorophosphonate, (a12) [4-(4-Acetylphenylthio)]phenyldiphenylsulfonium tris(pentafluorophenyl) trifluorophosphonate, 2. The onium salt according to claim 1, wherein The ratio of the face-type body is 0.1 wt% to 15.0 wt%.

3. A photoacid generator comprising the onium salt according to claim 1 or 2. 4 . A chemically amplified resist composition comprising the onium salt according to claim 1 .

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