WO2014061063A1 - Photo-acid generator, and resin composition for photolithography - Google Patents

Abstract

Provided are: a nonionic photo-acid generator having high photosensitivity to i-line, excellent heat resistance stability and excellent solubility in a hydrophobic material; and a resin composition for photolithography, which contains the nonionic photo-acid generator. The present invention relates to: (A) a nonionic photo-acid generator characterized by being represented by general formula (1); and (Q) a resin composition for photolithography, which contains the nonionic photo-acid generator (A). [In formula (1), x represents an integer of 1 to 8; y represents an integer of 3 to 17; R represents a phenyl group, a biphenyl group or a naphthyl group, each of which may have a substituent (T); and L represents -O-, -S-, -SO-, -SO₂-, -CO-, -COO-, -CONH-, an alkylene group having 1 to 3 carbon atoms, -CH=CH-, -C≡C- or a phenylene group.]

Description

Photoacid generator and resin composition for photolithography

The present invention relates to a photoacid generator and a resin composition for photolithography. More specifically, the present invention relates to a nonionic photoacid generator suitable for generating a strong acid by the action of ultraviolet rays (i rays), and a photolithographic resin composition containing the nonionic photoacid generator.

Conventionally, in the field of microfabrication represented by semiconductor manufacturing, a photolithography process using i-line having a wavelength of 365 nm as exposure light has been widely used.
As a resist material used in the photolithography process, for example, a resin composition containing a polymer having a tert-butyl ester group of carboxylic acid or a tert-butyl carbonate group of phenol and a photoacid generator is used. Yes. As photoacid generators, ionic photoacid generators such as triarylsulfonium salts (Patent Document 1), phenacylsulfonium salts having a naphthalene skeleton (Patent Document 2), and acid generators having an oxime sulfonate structure (Patent Documents) 3) Nonionic acid generators such as acid generators having a sulfonyldiazomethane structure (Patent Document 4) are known. By irradiating the resist material with ultraviolet rays, the photoacid generator is decomposed to generate a strong acid. Further, by performing post-exposure heating (PEB), the tert-butyl ester group or tert-butyl carbonate group in the polymer is dissociated by the strong acid to form a carboxylic acid or a phenolic hydroxyl group. It becomes readily soluble in an alkaline developer. Pattern formation is performed using this phenomenon.

However, as the photolithography process becomes finer, the influence of the swelling that the pattern of the light unexposed area is swollen by the alkali developer increases, and it is necessary to suppress the swelling of the resist material.
In order to solve these problems, a method of suppressing swelling of the resist material by making the polymer in the resist material hydrophobic by adding an alicyclic skeleton or a fluorine-containing skeleton has been proposed.

However, since ionic photoacid generators lack compatibility with hydrophobic materials containing alicyclic skeletons, fluorine-containing skeletons, etc., they can exhibit sufficient resist performance due to phase separation in resist materials. Therefore, there is a problem that the pattern cannot be formed. On the other hand, nonionic photoacid generators have good compatibility with hydrophobic materials, but the problem of insufficient sensitivity to i-line and the lack of heat resistance stability cause decomposition by post-exposure heating (PEB), and allowance. There is a narrow problem.

Japanese Patent Laid-Open No. 50-151997 JP-A-9-118663 Japanese Patent Laid-Open No. 06-77433 Japanese Patent Laid-Open No. 10-213899

Accordingly, it is an object to provide a nonionic photoacid generator having high photosensitivity to i-line, excellent heat resistance stability, and excellent solubility in hydrophobic materials.

The inventors of the present invention have reached the present invention as a result of studies to achieve the above object.
That is, the present invention provides a nonionic photoacid generator (A) represented by the following general formula (1); and a resin composition for photolithography comprising the nonionic photoacid generator (A) It is a thing (Q).

[In the formula (1), x is an integer of 1 to 8, y is an integer of 3 to 17, R is a phenyl group, biphenyl group or naphthyl group which may have a substituent (T), and L is —O—. , —S—, —SO—, —SO ₂ —, —CO—, —COO—, —CONH—, an alkylene group having 1 to 3 carbon atoms, —CH═CH—, —C≡C— or a phenylene group. To express. ]

Since the nonionic photoacid generator (A) of the present invention is nonionic, it is more compatible with a hydrophobic material than the ionic acid generator.
Further, since R is an aromatic group, the conjugated bond is long, the molar absorbance with respect to i-line is high, and the CxFy group having a high electron-withdrawing property is included, so that the sulfonate portion is easily cleaved. Thereby, by irradiating with i-line, the nonionic photoacid generator (A) can be easily decomposed to generate sulfonic acid which is a strong acid.
Furthermore, since the nonionic photoacid generator (A) contains a phthalimide skeleton and an aryl structure via L, it has excellent heat stability.

For this reason, the resin composition for photolithography (Q) containing the nonionic photoacid generator (A) of the present invention is highly sensitive to i-line and has an allowance in post-exposure heating (PEB). Excellent workability because it is wide.

Therefore, the nonionic photoacid generator (A) of the present invention is used for positive resists, resist films, liquid resists, negative resists, MEMS resists, photosensitive materials, nanoimprint materials, micro stereolithography materials, and the like. It is suitable as a photoacid generator. Moreover, the resin composition (Q) for photolithography of this invention is suitable for said use.

The nonionic acid generator (A) of the present invention is represented by the following general formula (1).

[In the formula (1), x is an integer of 1 to 8, y is an integer of 3 to 17, R is a phenyl group, biphenyl group or naphthyl group which may have a substituent (T), and L is —O—. , —S—, —SO—, —SO ₂ —, —CO—, —COO—, —CONH—, an alkylene group having 1 to 3 carbon atoms, —CH═CH—, —C≡C— or a phenylene group. To express. ]

The nonionic acid generator (A) of the present invention is characterized by generating sulfonic acid, which is a strong acid, by photolysis by ultraviolet irradiation, particularly i-line which is exposure light of 365 nm.
CxFy having a large electron-withdrawing property, which is an essential functional group for decomposing the sulfonate portion by ultraviolet irradiation, has 1 to 8 carbon atoms (x = 1 to 8) and 3 to 17 fluorine atoms (y = 3). To 17).
If the number of carbon atoms is 1 or more, the synthesis of strong acid is easy, and if it is 8 or less, the heat resistance stability is excellent. If the number of fluorine atoms is 3 or more, it can act as a strong acid, and if it is 17 or less, the synthesis of a strong acid is easy.
CxFy in the nonionic acid generator (A) may be used singly or in combination of two or more.

CxFy in the nonionic acid generator (A) includes a linear alkyl group (RF1), a branched alkyl group (RF2), a cycloalkyl group (RF3), and an aryl group in which a hydrogen atom is substituted with a fluorine atom. (RF4).

Examples of the linear alkyl group (RF1) in which a hydrogen atom is substituted with a fluorine atom include a trifluoromethyl group (x = 1, y = 3), a pentafluoroethyl group (x = 2, y = 5), nona Examples include a fluorobutyl group (x = 4, y = 9), a perfluorohexyl group (x = 6, y = 13), a perfluorooctyl group (x = 8, y = 17), and the like.

Examples of the branched alkyl group (RF2) in which a hydrogen atom is substituted with a fluorine atom include a perfluoroisopropyl group (x = 3, y = 7) and a perfluoro-tert-butyl group (x = 4, y = 9). And a perfluoro-2-ethylhexyl group (x = 8, y = 17) and the like.

Examples of the cycloalkyl group (RF3) in which a hydrogen atom is substituted with a fluorine atom include a perfluorocyclobutyl group (x = 4, y = 7), a perfluorocyclopentyl group (x = 5, y = 9), Examples thereof include a fluorocyclohexyl group (x = 6, y = 11) and a perfluoro (1-cyclohexyl) methyl group (x = 7, y = 13).

Examples of the aryl group (RF4) in which a hydrogen atom is substituted with a fluorine atom include a pentafluorophenyl group (x = 6, y = 5) and a 3-trifluoromethyltetrafluorophenyl group (x = 7, y = 7) and the like.

Of CxFy in the nonionic acid generator (A), from the viewpoint of availability and decomposability of the sulfonic acid ester portion, a linear alkyl group (RF1) or a branched alkyl group (RF2) is preferable. ), An aryl group (RF4), more preferably a linear alkyl group (RF1), and an aryl group (RF4), particularly preferably a trifluoromethyl group (x = 1, y = 3), a pentafluoroethyl group (x = 2, y = 5), heptafluoropropyl group (x = 3, y = 7), nonafluorobutyl group (x = 4, y = 9), and pentafluorophenyl group (x = 6, y = 5) It is.

R, which is an essential functional group for giving an absorption wavelength to i-line that is exposure light of 365 nm and improving heat resistance stability, is bonded to the phthalimide skeleton via L, and this R is: A phenyl group, a biphenyl group, or a naphthyl group which may have a substituent (T). Although the substituent (T) may not be contained, the solubility in the resist resin and the absorption wavelength region can be adjusted by introducing the substituent (T).

Examples of the substituent (T) include an alkyl group, a hydroxy group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, Examples thereof include an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, and a halogen atom. A substituent (T) may be used by 1 type and may use 2 or more types together.

Examples of the alkyl group include linear alkyl groups having 1 to 18 carbon atoms (methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n- Hexadecyl, n-octadecyl, etc.), branched alkyl groups having 1 to 18 carbon atoms (isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl and isooctadecyl), and 3 carbon atoms -18 cycloalkyl groups (cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 4-decylcyclohexyl, etc.), linear or branched fluoroalkyl groups having 1 to 3 carbon atoms (trifluoromethyl, pentafluoroethyl, heptafluorobutyl groups) Etc.).

Examples of the alkoxy group include linear or branched alkoxy groups having 1 to 18 carbon atoms (methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, hexyloxy, decyloxy, dodecyloxy and octadecyl Oxy and the like).

Examples of the alkylcarbonyl group include linear or branched alkylcarbonyl groups having 2 to 18 carbon atoms (including carbonyl carbon) (acetyl, propionyl, butanoyl, 2-methylpropionyl, heptanoyl, 2-methylbutanoyl, 3-methyl Butanoyl, octanoyl, decanoyl, dodecanoyl, octadecanoyl, etc.).

Examples of the arylcarbonyl group include arylcarbonyl groups having 7 to 11 carbon atoms (including carbonyl carbon) (such as benzoyl and naphthoyl).

Examples of the alkoxycarbonyl group include linear or branched alkoxycarbonyl groups having 2 to 19 carbon atoms (including carbonyl carbon) (methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, sec- Butoxycarbonyl, tert-butoxycarbonyl, octyloxycarbonyl, tetradecyloxycarbonyl, octadecyloxycarbonyl, etc.).

Examples of the aryloxycarbonyl group include aryloxycarbonyl groups having 7 to 11 carbon atoms (including carbonyl carbon) (such as phenoxycarbonyl and naphthoxycarbonyl).

Examples of the arylthiocarbonyl group include arylthiocarbonyl groups having 7 to 11 carbon atoms (including carbonyl carbon) (such as phenylthiocarbonyl and naphthoxythiocarbonyl).

Examples of the acyloxy group include linear or branched acyloxy groups having 2 to 19 carbon atoms (acetoxy, ethylcarbonyloxy, propylcarbonyloxy, isopropylcarbonyloxy, butylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy, tert- Butylcarbonyloxy, octylcarbonyloxy, tetradecylcarbonyloxy, octadecylcarbonyloxy and the like).

As the arylthio group, an arylthio group having 6 to 20 carbon atoms (phenylthio, 2-methylphenylthio, 3-methylphenylthio, 4-methylphenylthio, 2-chlorophenylthio, 3-chlorophenylthio, 4-chlorophenylthio, 2 -Bromophenylthio, 3-bromophenylthio, 4-bromophenylthio, 2-fluorophenylthio, 3-fluorophenylthio, 4-fluorophenylthio, 2-hydroxyphenylthio, 4-hydroxyphenylthio, 2-methoxy Phenylthio, 4-methoxyphenylthio, 1-naphthylthio, 2-naphthylthio, 4- [4- (phenylthio) benzoyl] phenylthio, 4- [4- (phenylthio) phenoxy] phenylthio, 4- [4- (phenylthio) phenyl ] Phenylthio, 4 (Phenylthio) phenylthio, 4-benzoylphenylthio, 4-benzoyl-2-chlorophenylthio, 4-benzoyl-3-chlorophenylthio, 4-benzoyl-3-methylthiophenylthio, 4-benzoyl-2-methylthiophenylthio, 4 -(4-methylthiobenzoyl) phenylthio, 4- (2-methylthiobenzoyl) phenylthio, 4- (p-methylbenzoyl) phenylthio, 4- (p-ethylbenzoyl) phenylthio 4- (p-isopropylbenzoyl) phenylthio and 4- (P-tert-butylbenzoyl) phenylthio and the like).

Examples of the alkylthio group include linear or branched alkylthio groups having 1 to 18 carbon atoms (methylthio, ethylthio, propylthio, isopropylthio, butylthio, isobutylthio, sec-butylthio, tert-butylthio, pentylthio, isopentylthio, neopenthi Luthio, tert-pentylthio, octylthio, decylthio, dodecylthio, isooctadecylthio and the like.

Examples of the aryl group include aryl groups having 6 to 10 carbon atoms (such as phenyl, tolyl, dimethylphenyl and naphthyl).

As the heterocyclic hydrocarbon group, a heterocyclic hydrocarbon group having 4 to 20 carbon atoms (thienyl, furanyl, pyranyl, pyrrolyl, oxazolyl, thiazolyl, pyridyl, pyrimidyl, pyrazinyl, indolyl, benzofuranyl, benzothienyl, quinolyl, isoquinolyl Quinoxalinyl, quinazolinyl, carbazolyl, acridinyl, phenothiazinyl, phenazinyl, xanthenyl, thianthenyl, phenoxazinyl, phenoxathinyl, chromanyl, isochromanyl, dibenzothienyl, xanthonyl, thioxanthonyl, dibenzofuranyl and the like.

Examples of the aryloxy group include aryloxy groups having 6 to 10 carbon atoms (such as phenoxy and naphthyloxy).

Examples of the alkylsulfinyl group include linear or branched sulfinyl groups having 1 to 18 carbon atoms (methylsulfinyl, ethylsulfinyl, propylsulfinyl, isopropylsulfinyl, butylsulfinyl, isobutylsulfinyl, sec-butylsulfinyl, tert-butylsulfinyl, pentyl) Sulfinyl, isopentylsulfinyl, neopentylsulfinyl, tert-pentylsulfinyl, octylsulfinyl, isooctadecylsulfinyl, etc.).

Examples of the arylsulfinyl group include arylsulfinyl groups having 6 to 10 carbon atoms (such as phenylsulfinyl, tolylsulfinyl and naphthylsulfinyl).

Examples of the alkylsulfonyl group include linear or branched alkylsulfonyl groups having 1 to 18 carbon atoms (methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl, isobutylsulfonyl, sec-butylsulfonyl, tert-butylsulfonyl, Pentylsulfonyl, isopentylsulfonyl, neopentylsulfonyl, tert-pentylsulfonyl, octylsulfonyl, octadecylsulfonyl, etc.).

Examples of the arylsulfonyl group include arylsulfonyl groups having 6 to 10 carbon atoms {phenylsulfonyl, tolylsulfonyl (tosyl group), naphthylsulfonyl, etc.}.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Among these substituents (T), from the viewpoint of ease of synthesis, absorption wavelength region, and heat stability, an alkyl group, an alkoxy group, an arylcarbonyl group, an aryloxycarbonyl group, an arylthio group, an aryl group, an aryloxy group An arylsulfinyl group, an arylsulfonyl group, a fluorine atom and a chlorine atom are preferable, and a methyl group, a tert-butyl group, a trifluoromethyl group, a fluorine and a chlorine atom are particularly preferable.

R is bonded to the phthalimide skeleton through L, and this L is —O—, —S—, —SO—, —SO ₂ —, —CO—, —COO—, —CONH—, carbon An alkylene group of 1 to 3; —CH═CH—, —C≡C— or a phenylene group.

Examples of the alkylene group having 1 to 3 carbon atoms of L include linear or branched alkylene groups having 1 to 3 carbon atoms such as methylene, ethylene and propylene.

Among these Ls, from the viewpoint of ease of synthesis, absorption wavelength region, and heat stability, —O—, —S—, —SO—, —CO—, —COO—, a methylene group, —CH═CH — And —C≡C— are preferred, and —O—, —S—, —CO—, —CH═CH— and —C≡C— are more preferred.

The method for synthesizing the nonionic acid generator (A) of the present invention is not particularly limited as long as the target product can be synthesized. For example, when L is —S—, nitrophthalimide or halogen-substituted phthalimide and a substituent ( T), a phthalimide compound (P1) obtained by reaction with thiophenol, biphenylthiol, or naphthalenethiol, or a salt of such thiol, which may have T. Ficher, Helv. Chem. Acta. , 74, 1119 (1991), etc., to make an anhydride compound (P2) and then reacting with hydroxylammonium chloride to give an N-hydroxyimide compound (P3). This N-hydroxyimide compound (P3 ) And a sulfonic acid anhydride represented by (CxFySO ₂ ) ₂ O, or a reaction of a salt of the N-hydroxyimide compound (P3) with a sulfonic acid chloride represented by CxFySO ₂ Cl.

Examples of the halogen-substituted phthalimide include fluorophthalimide, chlorophthalimide, bromophthalimide, and iodophthalimide.
The thiol substituent (T) used in the synthesis of the phthalimide compound (P1), the sulfonic acid anhydride used in the synthesis of the N-hydroxyimide compound (P3), and CxFy in the sulfonic acid chloride are represented by the formula (1) Same definition as in

The nonionic acid generator (A) of the present invention may be dissolved in advance in a solvent that does not inhibit the reaction in order to facilitate dissolution in the resist material.

Solvents include carbonates (propylene carbonate, ethylene carbonate, 1,2-butylene carbonate, dimethyl carbonate, diethyl carbonate, etc.); esters (ethyl acetate, ethyl lactate, β-propiolactone, β-butyrolactone, γ-butyrolactone, δ -Valerolactone and ε-caprolactone, etc.); ethers (ethylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol dimethyl ether, triethylene glycol diethyl ether, tripropylene glycol dibutyl ether, etc.); and ether esters ( Ethylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate And diethylene glycol monobutyl ether acetate, etc.) and the like.

When a solvent is used, the proportion of the solvent used is preferably 15 to 1000 parts by weight, more preferably 30 to 500 parts by weight with respect to 100 parts by weight of the photoacid generator of the present invention.

Since the resin composition for photolithography (Q) of the present invention contains the nonionic photoacid generator (A) as an essential component, the exposed portion and the unexposed portion are exposed by performing ultraviolet irradiation and post-exposure heating (PEB). Difference in solubility in the developer of the part. A nonionic photoacid generator (A) can be used individually by 1 type or in combination of 2 or more types.
Examples of the resin composition (Q) for photolithography include a mixture of a negative chemical amplification resin (QN) and a nonionic photoacid generator (A); and a positive chemical amplification resin (QP) and a nonionic photoacid. A mixture with a generator (A) is mentioned.

The negative chemical amplification resin (QN) is composed of a phenolic hydroxyl group-containing resin (QN1) and a crosslinking agent (QN2).

The phenolic hydroxyl group-containing resin (QN1) is not particularly limited as long as it contains a phenolic hydroxyl group. For example, a novolak resin, a polyhydroxystyrene, a copolymer of hydroxystyrene, a copolymer of hydroxystyrene and styrene Copolymer, copolymer of hydroxystyrene, styrene and (meth) acrylic acid derivative, phenol-xylylene glycol condensation resin, cresol-xylylene glycol condensation resin, polyimide containing phenolic hydroxyl group, polyamic acid containing phenolic hydroxyl group Phenol-dicyclopentadiene condensation resin is used. Among these, novolak resins, polyhydroxystyrene, copolymers of polyhydroxystyrene, copolymers of hydroxystyrene and styrene, copolymers of hydroxystyrene, styrene and (meth) acrylic acid derivatives, phenol-xylylene glycol Condensed resins are preferred. In addition, these phenolic hydroxyl group containing resin (QN1) may be used individually by 1 type, and 2 or more types may be mixed and used for it.

The novolak resin can be obtained, for example, by condensing phenols and aldehydes in the presence of a catalyst.
Examples of the phenols include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p-butylphenol, 2 , 3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5- Examples include trimethylphenol, catechol, resorcinol, pyrogallol, α-naphthol, β-naphthol and the like.
Examples of the aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, and benzaldehyde.

Specific examples of the novolak resin include phenol / formaldehyde condensed novolak resin, cresol / formaldehyde condensed novolak resin, phenol-naphthol / formaldehyde condensed novolak resin, and the like.

The phenolic hydroxyl group-containing resin (QN1) may contain a phenolic low molecular weight compound as a part of the component.
Examples of the phenolic low molecular weight compound include 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenyl ether, tris (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) -1- Phenylethane, tris (4-hydroxyphenyl) ethane, 1,3-bis [1- (4-hydroxyphenyl) -1-methylethyl] benzene, 1,4-bis [1- (4-hydroxyphenyl) -1 -Methylethyl] benzene, 4,6-bis [1- (4-hydroxyphenyl) -1-methylethyl] -1,3-dihydroxybenzene, 1,1-bis (4-hydroxyphenyl) -1- [4 -[1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethane, 1,1,2,2-tetra (4-hydroxy) Phenyl) ethane, 4,4 '- {1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene} bisphenol and the like. These phenolic low molecular weight compounds may be used alone or in combination of two or more.

The content ratio of the phenolic low molecular weight compound in the phenolic hydroxyl group-containing resin (QN1) is preferably 40% by weight or less, more preferably, based on 100% by weight of the phenolic hydroxyl group-containing resin (QN1). 1 to 30% by weight.

The weight average molecular weight of the phenolic hydroxyl group-containing resin (QN1) is preferably 2000 or more, more preferably 2000 from the viewpoint of the resolution, thermal shock resistance, heat resistance, residual film ratio, etc. of the obtained insulating film. About 20,000.
In addition, the content of the phenolic hydroxyl group-containing resin (QN1) in the negative chemically amplified resin (QN) is 30 to 90% by weight when the total composition excluding the solvent is 100% by weight. Is more preferable, and 40 to 80% by weight is more preferable. When the content of the phenolic hydroxyl group-containing resin (QN1) is 30 to 90% by weight, the film formed using the photosensitive insulating resin composition has sufficient developability with an alkaline aqueous solution. Therefore, it is preferable.

The crosslinking agent (QN2) is not particularly limited as long as it is a compound that can crosslink the phenolic hydroxyl group-containing resin (QN1) with a strong acid generated from the nonionic photoacid generator (A).

Examples of the crosslinking agent (QN2) include bisphenol A epoxy compounds, bisphenol F epoxy compounds, bisphenol S epoxy compounds, novolac resin epoxy compounds, resole resin epoxy compounds, poly (hydroxystyrene) epoxy compounds, and oxetanes. Compound, methylol group-containing melamine compound, methylol group-containing benzoguanamine compound, methylol group-containing urea compound, methylol group-containing phenol compound, alkoxyalkyl group-containing melamine compound, alkoxyalkyl group-containing benzoguanamine compound, alkoxyalkyl group-containing urea compound, alkoxyalkyl group -Containing phenol compound, carboxymethyl group-containing melamine resin, carboxymethyl group-containing benzoguanamine resin, carboxymethyl group-containing urea Fat, carboxymethyl group-containing phenol resin, carboxymethyl group-containing melamine compounds, carboxymethyl group-containing benzoguanamine compounds, mention may be made of carboxymethyl group-containing urea compounds and carboxymethyl group-containing phenol compounds and the like.

Among these crosslinking agents (QN2), methylol group-containing phenol compounds, methoxymethyl group-containing melamine compounds, methoxymethyl group-containing phenol compounds, methoxymethyl group-containing glycoluril compounds, methoxymethyl group-containing urea compounds and acetoxymethyl group-containing phenol compounds More preferred are methoxymethyl group-containing melamine compounds (for example, hexamethoxymethyl melamine), methoxymethyl group-containing glycoluril compounds, methoxymethyl group-containing urea compounds, and the like. The methoxymethyl group-containing melamine compound is a trade name such as CYMEL300, CYMEL301, CYMEL303, CYMEL305 (manufactured by Mitsui Cyanamid Co., Ltd.), and the methoxymethyl group-containing glycoluril compound is a trade name such as CYMEL1174 (manufactured by Mitsui Cyanamid Co., Ltd.). Further, the methoxymethyl group-containing urea compound is commercially available under a trade name such as MX290 (manufactured by Sanwa Chemical Co., Ltd.).

The content of the crosslinking agent (QN2) is usually 5 to 5 with respect to all acidic functional groups in the phenolic hydroxyl group-containing resin (QN1) from the viewpoints of reduction of the remaining film ratio, pattern meandering and swelling, and developability. The amount is 60 mol%, preferably 10 to 50 mol%, more preferably 15 to 40 mol%.

As a positive chemical amplification resin (QP), a part of hydrogen atoms of acidic functional groups in an alkali-soluble resin (QP1) containing one or more acidic functional groups such as phenolic hydroxyl group, carboxyl group, or sulfonyl group Or the protecting group introduction | transduction resin (QP2) which substituted all by the acid dissociable group is mentioned.
The acid dissociable group is a group that can be dissociated in the presence of a strong acid generated from the nonionic photoacid generator (A).
The protecting group-introduced resin (QP2) is itself insoluble in alkali or hardly soluble in alkali.

Examples of the alkali-soluble resin (QP1) include a phenolic hydroxyl group-containing resin (QP11), a carboxyl group-containing resin (QP12), and a sulfonic acid group-containing resin (QP13).
As the phenolic hydroxyl group-containing resin (QP11), the same phenolic hydroxyl group-containing resin (QN1) can be used.

The carboxyl group-containing resin (QP12) is not particularly limited as long as it is a polymer having a carboxyl group. For example, vinyl polymerization of a carboxyl group-containing vinyl monomer (Ba) and, if necessary, a hydrophobic group-containing vinyl monomer (Bb) is vinyl-polymerized. It is obtained by doing.

Examples of the carboxyl group-containing vinyl monomer (Ba) include unsaturated monocarboxylic acids [(meth) acrylic acid, crotonic acid, cinnamic acid, etc.], unsaturated polyvalent (2- to 4-valent) carboxylic acids [(anhydrous) maleic acid, and the like. Acid, itaconic acid, fumaric acid, citraconic acid and the like], unsaturated polyvalent carboxylic acid alkyl (alkyl group having 1 to 10 carbon atoms) ester [maleic acid monoalkyl ester, fumaric acid monoalkyl ester, citraconic acid monoalkyl ester, etc. And salts thereof [alkali metal salts (sodium salt, potassium salt, etc.), alkaline earth metal salts (calcium salt, magnesium salt, etc.), amine salts, ammonium salts, etc.].
Of these, unsaturated monocarboxylic acids are preferred from the viewpoint of polymerizability and availability, and (meth) acrylic acid is more preferred.

Examples of the hydrophobic group-containing vinyl monomer (Bb) include (meth) acrylic acid ester (Bb1) and aromatic hydrocarbon monomer (Bb2).

Examples of the (meth) acrylic acid ester (Bb1) include alkyl (meth) acrylates having 1 to 20 carbon atoms in the alkyl group [for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, Isopropyl (meth) acrylate, n-butyl (meth) acrylate, n-hexyl (meth) acrylate and 2-ethylhexyl (meth) acrylate, etc.] and alicyclic group-containing (meth) acrylate [dicyclopentanyl (meth) acrylate, Sidiclopentenyl (meth) acrylate, isobornyl (meth) acrylate, etc.].

Examples of the aromatic hydrocarbon monomer (Bb2) include hydrocarbon monomers having a styrene skeleton [for example, styrene, α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene. Cyclohexyl styrene and benzyl styrene] and vinyl naphthalene.

The charged monomer molar ratio of (Ba) / (Bb) in the carboxyl group-containing resin (QP12) is usually from 10 to 100/0 to 90, preferably from 10 to 80/20 to 90, more preferably from the viewpoint of developability. 25-85 / 15-75.

The sulfonic acid group-containing resin (QP13) is not particularly limited as long as it is a polymer having a sulfonic acid group. For example, a sulfonic acid group-containing vinyl monomer (Bc) and, if necessary, a hydrophobic group-containing vinyl monomer (Bb) are used. Obtained by vinyl polymerization.
As the hydrophobic group-containing vinyl monomer (Bb), the same ones as described above can be used.

Examples of the sulfonic acid group-containing vinyl monomer (Bc) include vinyl sulfonic acid, (meth) allyl sulfonic acid, styrene sulfonic acid, α-methyl styrene sulfonic acid, 2- (meth) acryloylamide-2-methylpropane sulfonic acid. And salts thereof. Examples of the salt include alkali metal (such as sodium and potassium) salts, alkaline earth metal (such as calcium and magnesium) salts, primary to tertiary amine salts, ammonium salts and quaternary ammonium salts.

In the sulfonic acid group-containing resin (QP13), the charged monomer molar ratio of (Bc) / (Bb) is usually 10 to 100/0 to 90, preferably 10 to 80/20 to 90, more preferably from the viewpoint of developability. Is 25 to 85/15 to 75.

The preferred range of the HLB value of the alkali-soluble resin (QP1) varies depending on the resin skeleton of the alkali-soluble resin (QP1), but is preferably 4 to 19, more preferably 5 to 18, and particularly preferably 6 to 17.
When the HLB value is 4 or more, developability is further improved when developing, and when it is 19 or less, the water resistance of the cured product is further improved.

The HLB in the present invention is an HLB value according to the Oda method, which is a hydrophilic-hydrophobic balance value, and can be calculated from the ratio between the organic value and the inorganic value of the organic compound.
HLB≈10 × Inorganic / Organic In addition, the inorganic value and the organic value are described in the document “Surfactant Synthesis and Applications” (published by Tsuji Shoten, Oda, Teramura), page 501; It is described in detail on page 198 of “Introduction to New Surfactants” (Takehiko Fujimoto, published by Sanyo Chemical Industries, Ltd.).

Examples of the acid dissociable group in the protecting group-introduced resin (QP2) include a substituted methyl group, 1-substituted ethyl group, 1-branched alkyl group, silyl group, germyl group, alkoxycarbonyl group, acyl group, and cyclic acid. Examples include a dissociable group. These may be used alone or in combination of two or more.

Examples of the 1-substituted methyl group include methoxymethyl group, methylthiomethyl group, ethoxymethyl group, ethylthiomethyl group, methoxyethoxymethyl group, benzyloxymethyl group, benzylthiomethyl group, phenacyl group, bromophenacyl group, methoxyphena Sil group, methylthiophenacyl group, α-methylphenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, bromobenzyl group, nitrobenzyl group, methoxybenzyl group, methylthiobenzyl group, ethoxybenzyl Group, ethylthiobenzyl group, piperonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, n-propoxycarbonylmethyl group, i-propoxycarbonylmethyl group, n-butoxycarbonylmethyl group, tert-butyl group Alkoxycarbonylmethyl group, and the like.

Examples of the 1-substituted ethyl group include 1-methoxyethyl group, 1-methylthioethyl group, 1,1-dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, 1,1-diethoxyethyl. Group, 1-ethoxypropyl group, 1-propoxyethyl group, 1-cyclohexyloxyethyl group, 1-phenoxyethyl group, 1-phenylthioethyl group, 1,1-diphenoxyethyl group, 1-benzyloxyethyl group, 1-benzylthioethyl group, 1-cyclopropylethyl group, 1-phenylethyl group, 1,1-diphenylethyl group, 1-methoxycarbonylethyl group, 1-ethoxycarbonylethyl group, 1-n-propoxycarbonylethyl group 1-isopropoxycarbonylethyl group, 1-n-butoxycarbonylethyl group, 1-tert- Butoxycarbonyl ethyl group and the like.

Examples of the 1-branched alkyl group include i-propyl group, sec-butyl group, tert-butyl group, 1,1-dimethylpropyl group, 1-methylbutyl group, 1,1-dimethylbutyl group and the like. it can.

Examples of the silyl group include trimethylsilyl group, ethyldimethylsilyl group, methyldiethylsilyl group, triethylsilyl group, i-propyldimethylsilyl group, methyldi-i-propylsilyl group, tri-i-propylsilyl group, tert-butyl. Examples thereof include tricarbylsilyl groups such as dimethylsilyl group, methyldi-tert-butylsilyl group, tri-tert-butylsilyl group, phenyldimethylsilyl group, methyldiphenylsilyl group, and triphenylsilyl group.

Examples of the germyl group include trimethylgermyl group, ethyldimethylgermyl group, methyldiethylgermyl group, triethylgermyl group, isopropyldimethylgermyl group, methyldi-i-propylgermyl group, and tri-i-propylgel. Tricarbylgermyl groups such as mil group, tert-butyldimethylgermyl group, methyldi-tert-butylgermyl group, tri-tert-butylgermyl group, phenyldimethylgermyl group, methyldiphenylgermyl group, triphenylgermyl group, etc. Can be mentioned.

Examples of the alkoxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, i-propoxycarbonyl group, tert-butoxycarbonyl group and the like.

Acyl groups include, for example, acetyl, propionyl, butyryl, heptanoyl, hexanoyl, valeryl, pivaloyl, isovaleryl, lauroyl, myristoyl, palmitoyl, stearoyl, oxalyl, malonyl, succinyl Group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacoyl group, acryloyl group, propioroyl group, methacryloyl group, crotonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconoyl group, camphoroyl group, benzoyl group , Phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group, cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group, isonicoti Yl group, p- toluenesulfonyl group, and mesyl group.

Examples of the cyclic acid dissociable group include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a 4-methoxycyclohexyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group, and a tetrahydrothiofuranyl group. Group, 3-bromotetrahydropyranyl group, 4-methoxytetrahydropyranyl group, 4-methoxytetrahydrothiopyranyl group, 3-tetrahydrothiophene-1,1-dioxide group and the like.

Among these acid dissociable groups, tert-butyl group, benzyl group, 1-methoxyethyl group, 1-ethoxyethyl group, trimethylsilyl group, tert-butoxycarbonyl group, tert-butoxycarbonylmethyl group, tetrahydropyranyl group, A tetrahydrofuranyl group, a tetrahydrothiopyranyl group, a tetrahydrofuranyl group, and the like are preferable.

Introduction rate of acid-dissociable groups in protecting group-introducing resin (QP2) {Ratio of the number of acid-dissociable groups to the total number of unprotected acidic functional groups and acid-dissociable groups in protecting group-introducing resin (QP2) } Cannot be generally defined by the type of acid-dissociable group or the alkali-soluble resin into which the group is introduced, but is preferably 10 to 100%, more preferably 15 to 100%.

The polystyrene-converted weight average molecular weight (hereinafter referred to as “Mw”) of the protecting group-introduced resin (QP2) measured by gel permeation chromatography (GPC) is preferably 1,000 to 150,000, more preferably 3, 000 to 100,000.

The ratio (Mw / Mn) of the Mw of the protecting group-introduced resin (QP2) and the polystyrene-equivalent number average molecular weight (hereinafter referred to as “Mn”) measured by gel permeation chromatography (GPC) is usually 1 To 10, preferably 1 to 5.

The content of the nonionic photoacid generator (A) based on the weight of the solid content of the resin composition for photolithography (Q) is preferably 0.001 to 20% by weight, more preferably 0.01 to 15% by weight. %, Particularly preferably 0.05 to 7% by weight.
If it is 0.001% by weight or more, the sensitivity to ultraviolet rays can be exhibited more satisfactorily, and if it is 20% by weight or less, the physical properties of the insoluble part in the alkali developer can be exhibited more satisfactorily.

The resist using the resin composition for photolithography (Q) of the present invention is prepared by, for example, applying a resin solution dissolved in a predetermined organic solvent (dissolved and dispersed when inorganic fine particles are included) to a spin coat, curtain coat, roll It can be formed by drying the solvent by heating or hot air blowing after applying to the substrate using a known method such as coating, spray coating or screen printing.

The organic solvent for dissolving the resin composition for photolithography (Q) is particularly limited as long as the resin composition can be dissolved and the resin solution can be adjusted to physical properties (viscosity, etc.) applicable to spin coating or the like. Not. For example, known solvents such as N-methylpyrrolidone, N, N-dimethylformamide, dimethyl sulfoxide, toluene, ethanol, cyclohexanone, methanol, methyl ethyl ketone, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate, acetone and xylene Can be used.
Among these solvents, those having a boiling point of 200 ° C. or less (toluene, ethanol, cyclohexanone, methanol, methyl ethyl ketone, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate, acetone and xylene) from the viewpoint of drying temperature and the like Are preferable, and can be used alone or in combination of two or more.
When an organic solvent is used, the amount of the solvent is not particularly limited, but is usually preferably 30 to 1,000% by weight, more preferably based on the weight of the solid content of the resin composition for photolithography (Q). It is 40 to 900% by weight, particularly preferably 50 to 800% by weight.

The drying condition of the resin solution after coating varies depending on the solvent used, but is preferably carried out at 50 to 200 ° C. for 2 to 30 minutes, and the residual solvent amount of the resin composition for photolithography (Q) after drying ( Weight%) and the like.

After the resist is formed on the substrate, the wiring pattern shape is irradiated with light. Then, after performing post-exposure heating (PEB), alkali development is performed to form a wiring pattern.

Examples of the light irradiation method include a method of exposing the resist with active light through a photomask having a wiring pattern. The actinic ray used for the light irradiation is not particularly limited as long as the nonionic photoacid generator (A) in the resin composition for photolithography (Q) of the present invention can be decomposed.
Actinic rays include low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, xenon lamp, metal halogen lamp, electron beam irradiation device, X-ray irradiation device, laser (argon laser, dye laser, nitrogen laser, LED, helium Cadmium laser). Of these, high pressure mercury lamps and ultrahigh pressure mercury lamps are preferred.

The post-exposure heating (PEB) temperature is usually 40 to 200 ° C., preferably 500 to 190 ° C., more preferably 60 to 180 ° C. If the temperature is lower than 40 ° C., the deprotection reaction or the crosslinking reaction cannot be sufficiently performed. Therefore, there is not enough difference in solubility between the ultraviolet irradiated portion and the ultraviolet unirradiated portion, and a pattern cannot be formed. There is.
The heating time is usually 0.5 to 120 minutes, preferably 1 to 90 minutes, and more preferably 2 to 90 minutes. If it is less than 0.5 minutes, it is difficult to control the time and temperature, and if it is more than 120 minutes, there is a problem that productivity is lowered.

Examples of the alkali developing method include a method of dissolving and removing the wiring pattern shape using an alkali developer. The alkali developer is not particularly limited as long as the solubility of the ultraviolet-irradiated part and the ultraviolet-irradiated part of the resin composition for photolithography (Q) can be varied.
Examples of the alkali developer include a sodium hydroxide aqueous solution, a potassium hydroxide aqueous solution, sodium hydrogen carbonate, and a tetramethylammonium salt aqueous solution.
These alkaline developers may contain a water-soluble organic solvent. Examples of the water-soluble organic solvent include methanol, ethanol, isopropyl alcohol, tetrahydrofuran, N-methylpyrrolidone and the like.

As a developing method, there are a dip method, a shower method, and a spray method using an alkaline developer, but the spray method is more preferable.
The temperature of the developer is preferably 25 to 40 ° C. The development time is appropriately determined according to the resist thickness.

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Hereinafter, unless otherwise specified, “%” represents “% by weight” and “parts” represents “parts by weight”.

Production Example 1
<Synthesis of N-hydroxy-4-phenylthiophthalimide (P3-1)>

Sodium hydroxide (3.2 g, 80 mmol) was charged into a three-necked flask containing thiophenol (8.6 g, 78 mmol) and DMF (40 ml), and stirred at 60 ° C. for 1 hour. Subsequently, 4-nitrophthalimide (10.0 g, 52 mmol) was added and stirred for 5 hours, and then the reaction solution was added to 1 L of a 0.1 mol / L hydrochloric acid aqueous solution to recover an insoluble part. This insoluble part was put into 1 L of 0.2 mol / L sodium hydroxide aqueous solution and stirred at 90 ° C. for 3 hours to dissolve. The mixture was acidified with 35% hydrochloric acid, stirred at 90 ° C. for 6 hours, and then cooled to room temperature, and the precipitate was collected to obtain a white solid (P1-1) (23 g, 46 mmol).

White crystals (P1-1) (7.5 g, 27 mmol), acetic anhydride (35 g, 343 mmol), and xylene (250 ml) were added to a three-necked flask equipped with a reflux tube, and reacted at 140 ° C. for 5 hours with stirring. did. Subsequently, the acid anhydride and xylene were removed under reduced pressure to obtain a white solid (P2-1) (6.6 g, 26 mmol).

Next, white crystals (P2-1) (5.0 g, 19 mmol), H ₂ NOH · HCL (6.7 g, 97 mmol), and pyridine (45 ml) were added to a three-necked flask equipped with a reflux tube while stirring. The reaction was carried out at 100 ° C. for 10 hours. Subsequently, the reaction liquid was thrown into 1 mol / L hydrochloric acid aqueous solution, and deposits were collect | recovered. Further, recrystallization from ethanol gave a yellow solid (P3-1) (4.6 g, 17 mmol).

Production Example 2
<Synthesis of N-hydroxy-4-naphthylthiophthalimide (P3-2)>

A yellow solid (P3-2) (4.8 g, 15 mmol) was obtained in the same manner as in Production Example 1, except that thiophenol (8.6 g, 78 mmol) was changed to 2-naphthalenethiol (8.8 g, 55 mmol). It was.

Production Example 3
<Synthesis of N-hydroxy-4- (4-methylphenyl) thiophthalimide (P3-3)>

A yellow solid (P3-3) (4.8 g, 17 mmol) was obtained in the same manner as in Production Example 1, except that thiophenol (8.6 g, 78 mmol) was changed to 3-methylthiophenol (9.7 g, 78 mmol). It was.

Comparative production example 1
<Synthesis of N-hydroxy-4-butylthiophthalimide (P3'-1)>

A yellow solid (P3′-1) (5.4 g, 18 mmol) was obtained in the same manner as in Production Example 1, except that thiophenol (8.6 g, 78 mmol) was changed to butylthiol (7.2 g, 80 mmol). .

Example 1
<Synthesis of Nonionic Photoacid Generator (A-1)>

A yellow solid (P3-1) (4.0 g, 15 mmol) synthesized in Production Example 1 and isopropyl alcohol (80 ml) are added and dissolved. Next, a 10% aqueous tert-butoxy sodium solution (14.0 g, 15 mmol) was added dropwise with stirring, and the mixture was stirred at 40 ° C. for 2 hours. The precipitate was collected after cooling to room temperature to obtain a red solid (3.8 g, 13 mmol).
Trifluoromethanesulfonic acid chloride (0.4 g, 2.4 mmol) was added dropwise to a three-necked flask containing this red solid (0.5 g, 1.7 mmol) and THF (35 ml) with stirring at 0 ° C. Then, it stirred at 25 degreeC for 2 hours. The reaction solution was extracted with toluene-water, and then the toluene layer was removed under reduced pressure to remove the solvent to obtain a yellow solid. Further, recrystallization was performed with acetone / isopropyl alcohol to obtain a nonionic photoacid generator (A-1) (0.4 g, 0.9 mmol).

Example 2
<Synthesis of Nonionic Photoacid Generator (A-2)>

A nonionic photoacid generator in the same manner as in Example 1 except that trifluoromethanesulfonic acid chloride (0.4 g, 2.4 mmol) was changed to pentafluorobenzenesulfonic acid chloride (0.6 g, 2.4 mmol). (A-2) (0.4 g, 0.9 mmol) was obtained.

Example 3
<Synthesis of nonionic photoacid generator (A-3)>

A non-ion was obtained in the same manner as in Example 1 except that the yellow solid (P3-1) (4.0 g, 15 mmol) was changed to the yellow solid (P3-2) (4.8 g, 15 mmol) synthesized in Preparation Example 2. A photoacid generator (A-3) (0.6 g, 1.0 mmol) was obtained.

Example 4
<Synthesis of Nonionic Photoacid Generator (A-4)>

A non-ion was obtained in the same manner as in Example 2 except that the yellow solid (P3-1) (4.0 g, 15 mmol) was changed to the yellow solid (P3-3) (4.0 g, 15 mmol) synthesized in Preparation Example 3. System photoacid generator (A-4) (0.4 g, 0.8 mmol) was obtained.

Example 5
<Synthesis of Nonionic Photoacid Generator (A-5)>

Nonionic photoacid generator in the same manner as in Example 1 except that the yellow solid (P3-1) (4.0 g, 15 mmol) was changed to N-hydroxy-4-phenoxyphthalimide (3.8 g, 15 mmol). (A-5) (0.4 g, 1.0 mmol) was obtained.

Example 6
<Synthesis of Nonionic Photoacid Generator (A-6)>

Nonionic photoacid generator in the same manner as in Example 1 except that the yellow solid (P3-1) (4.0 g, 15 mmol) was changed to N-hydroxy-4-benzoylphthalimide (4.0 g, 15 mmol). (A-6) (0.4 g, 1.0 mmol) was obtained.

Example 7
<Synthesis of Nonionic Photoacid Generator (A-7)>

Nonionic photoacid generator in the same manner as in Example 1 except that the yellow solid (P3-1) (4.0 g, 15 mmol) was changed to N-hydroxy-4-styrylphthalimide (3.8 g, 15 mmol). (A-7) (0.4 g, 1.0 mmol) was obtained.

Example 8
<Synthesis of Nonionic Photoacid Generator (A-8)>

Nonionic photoacid generation in the same manner as in Example 1, except that the yellow solid (P3-1) (4.0 g, 15 mmol) was changed to N-hydroxy-4-phenylethynylphthalimide (3.8 g, 15 mmol). Agent (A-8) (0.4 g, 1.0 mmol) was obtained.

Example 9
<Synthesis of Nonionic Photoacid Generator (A-9)>

Nonionic photoacid generator in the same manner as in Example 1 except that the yellow solid (P3-1) (4.0 g, 15 mmol) was changed to N-hydroxy-4-benzylphthalimide (3.8 g, 15 mmol). (A-9) (0.4 g, 1.0 mmol) was obtained.

Example 10
<Synthesis of Nonionic Photoacid Generator (A-10)>

The same procedure as in Example 1 except that the yellow solid (P3-1) (4.0 g, 15 mmol) was changed to N-hydroxy-4- (4-trifluoromethylphenyl) thiophthalimide (5.1 g, 15 mmol). Thus, a nonionic photoacid generator (A-10) (0.5 g, 1.0 mmol) was obtained.

Example 11
<Synthesis of Nonionic Photoacid Generator (A-11)>

Except that the yellow solid (P3-1) (4.0 g, 15 mmol) was changed to N-hydroxy-4- (4-chlorophenyl) thiophthalimide (4.6 g, 15 mmol), a non-ion was obtained in the same manner as in Example 1. System photoacid generator (A-11) (0.4 g, 1.0 mmol) was obtained.

Comparative Example 1
<Synthesis of Nonionic Photoacid Generator (A'-1)>

A nonionic photoacid generator in the same manner as in Example 1 except that trifluoromethanesulfonic acid chloride (0.4 g, 2.4 mmol) was changed to p-toluenesulfonic acid chloride (0.5 g, 2.4 mmol). (A′-1) (0.5 g, 1.0 mmol) was obtained.

Comparative Example 2
<Synthesis of Nonionic Photoacid Generator (A'-2)>

Except for changing the yellow solid (P3-1) (4.0 g, 15 mmol) to the yellow solid (P3′-1) (3.7 g, 15 mmol) synthesized in Comparative Production Example 1, the same procedure as in Example 1 was performed. A nonionic photoacid generator (A′-2) (0.3 g, 0.8 mmol) was obtained.

Comparative Example 3
<Synthesis of nonionic photoacid generator (A'-3)>

A nonionic photoacid generator (A ′) was obtained in the same manner as in Example 1 except that the yellow solid (P3-1) (4.0 g, 15 mmol) was changed to N-hydroxynaphthalimide (3.2 g, 15 mmol). -3) (0.4 g, 1.1 mmol) was obtained.

Comparative Example 4
<Synthesis of Ionic Photoacid Generator (A'-4)>

While stirring 12.1 parts of diphenyl sulfoxide, 9.3 parts of diphenyl sulfide and 43.0 parts of methanesulfonic acid, 7.9 parts of acetic anhydride was added dropwise thereto and reacted at 40-50 ° C. for 5 hours. After cooling to 25 ° C., this reaction solution was put into 121 parts of a potassium fluomethanesulfonate aqueous solution and stirred at 50 ° C. for 8 hours to precipitate a yellow slightly viscous oil. This oily substance was extracted with ethyl acetate, the organic layer was washed several times with water, the solvent was distilled off from the organic layer, and the resulting residue was dissolved by adding toluene. The mixture was stirred well for 1 hour and allowed to stand. After 1 hour, since the solution was separated into two layers, the upper layer was removed by liquid separation. When hexane was added to the remaining lower layer and mixed well at 25 ° C., pale yellow crystals were precipitated. This was filtered off and dried under reduced pressure to obtain an ionic photoacid generator (A′-4) in a yield of 60%.

<Performance evaluation>
As the performance evaluation of the photoacid generator, the obtained nonionic photoacid generators (A-1) to (A-11) and the nonionic photoacid generators (A′-1) to (A′−) 3) and the molar extinction coefficient, resist curability, thermal decomposition temperature, and solvent solubility of the ionic acid generator (A′-4) were evaluated by the following methods.

<Molar extinction coefficient>
The synthesized photoacid generator was diluted to 0.25 mmol / L with acetonitrile, and the absorbance of a cell length of 1 cm was measured in the range of 200 nm to 500 nm using an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, UV-2550). It was measured. From the following formula (2), the molar extinction coefficient (ε ₃₆₅ ) of i-line (365 nm) was calculated.
ε ₃₆₅ (L · mol ⁻¹ · cm ⁻¹ ) = A ₃₆₅ /(0.00025 mol / L × ¹ cm) (2)
[In Formula (2), A365 represents the light absorbency of ₃₆₅ nm. ]

<Resistance curability>
75 parts of phenolic resin (manufactured by DIC, “Phenolite TD431”), 25 parts of melamine curing agent (manufactured by Mitsui Cyanamid Co., Ltd., “Cymel 300”), 1 part of synthesized photoacid generator, and propylene glycol monomethyl ether 200 parts of a resin solution of acetate (hereinafter abbreviated as PGMEA) was applied on a 10 cm glass substrate using a spin coater at 1000 rpm for 10 seconds. Next, after vacuum drying at 25 ° C. for 5 minutes, it was dried on a hot plate at 80 ° C. for 3 minutes to form a resist having a film thickness of about 3 μm.
An ultraviolet ray irradiation device (OMW Corporation, HMW-661F-01) is used for this resist, and the wavelength is limited by an L-34 (Kenko Optical Co., Ltd. filter that cuts light of less than 340 nm) filter. A predetermined amount of light was exposed on the entire surface. The integrated exposure was measured at a wavelength of 365 nm.
Subsequently, after carrying out post-exposure heating (PEB) for 10 minutes with a 120 ° C forward air dryer, development was performed by immersing in a 0.5% potassium hydroxide solution for 30 seconds, followed by immediately washing with water and drying.
The film thickness of this resist was measured using a shape measuring microscope (ultra-deep shape measuring microscope VK-8550, manufactured by Keyence Corporation).
Here, the resist curability was evaluated according to the following criteria from the minimum exposure amount at which the change in resist film thickness before and after development was within 10%.
○: minimum exposure amount 250 mJ / cm ² or less △: Minimum exposure amount greater than ^{250mJ / cm 2, 500mJ / cm} 2 or less ×: Minimum exposure amount is greater than 500 mJ / cm ²

<Thermal decomposition temperature>
Using the differential thermal / thermogravimetric simultaneous measurement device (TG / DTA6200, manufactured by SII), the synthesized photoacid generator was subjected to a change in weight under a nitrogen atmosphere from 30 ° C. to 500 ° C. under a temperature rising condition of 10 ° C./min. The point at which the weight decreased by 2% was defined as the thermal decomposition temperature.

<Solvent solubility>
The synthesized photoacid generator was placed in a 0.1 g test tube, and 0.2 g of organic solvent (butyl acetate, toluene, and PGMEA) was added under 25 ° C. temperature control until the photoacid generator was completely dissolved. When 20 g was not completely dissolved, it was evaluated as not dissolved.

Nonionic photoacid generators (A-1) to (A-11) of the present invention prepared in Examples 1 to 11 and nonionic photoacid generators for comparison prepared in Comparative Examples 1 to 3 The molar extinction coefficient, thermal decomposition temperature, and solvent solubility of the ionic acid generator (A′-4) for comparison prepared in (A′-1) to (A′-3) and Comparative Example 4 Measurement was performed by the method described above. The results are shown in Tables 1 and 2.

As is clear from Tables 1 and 2, the nonionic photoacid generators (A) of Examples 1 to 11 of the present invention have a molar extinction coefficient of i-line (365 nm) of 3,000 mol ⁻¹ · cm ^−1. As can be seen from the above, the resist curability is good. In particular, in Example 2 having a naphthalene group, it can be seen that the sensitivity to i-line is particularly excellent. Moreover, it is understood that the thermal decomposition temperature is 260 ° C. or higher, and the solvent solubility is excellent.
On the other hand, in Comparative Example 1 in which CxFy has a p-toluene group having a low electron-withdrawing property, the sulfonic acid ester moiety is inferior in decomposability, but although the molar extinction coefficient is high, the resist curability is inferior. It can be seen that Comparative Example 2 which does not have a low molar extinction coefficient is inferior in resist curability. Moreover, it turns out that the thermal decomposition temperature is inferior in the comparative example 3 which does not have a phthalimide skeleton.
On the other hand, it can be seen that Comparative Example 4, which is an ionic acid generator, lacks solvent solubility in hydrophobic solvents such as butyl acetate and toluene.

The nonionic photoacid generator (A) of the present invention is a light used for positive resists, resist films, liquid resists, negative resists, MEMS resists, photosensitive materials, nanoimprint materials, micro stereolithography materials, and the like. Suitable as an acid generator. Moreover, the resin composition (Q) for photolithography of this invention is suitable for said use.

Claims (6)

A nonionic photoacid generator (A) represented by the following general formula (1):

[In the formula (1), x is an integer of 1 to 8, y is an integer of 3 to 17, R is a phenyl group, biphenyl group or naphthyl group which may have a substituent (T), and L is —O—. , —S—, —SO—, —SO ₂ —, —CO—, —COO—, —CONH—, an alkylene group having 1 to 3 carbon atoms, —CH═CH—, —C≡C— or a phenylene group. To express. ] In the general formula (1), the substituent (T) in R is an alkyl group, a hydroxy group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group. The nonionic system according to claim 1, which is an arylthio group, an alkylthio group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, or a halogen atom. Photoacid generator (A). The nonionic photoacid generator (A) according to claim 1, wherein R in the general formula (1) does not have a substituent (T). The nonionic light according to any one of claims 1 to 3, wherein in the general formula (1), L is -O-, -S-, -CO-, -CH = CH-, or -C≡C-. Acid generator (A). The nonionic photoacid according to any one of claims 1 to 4, wherein in the general formula (1), CxFy is CF ₃ , C ₂ F ₅ , C ₃ F ₇ , C ₄ F ₉ , or C ₆ F _5. Generator (A). A resin composition for photolithography (Q) comprising the nonionic photoacid generator (A) according to any one of claims 1 to 5.