KR20210092713A - Photoacid generator and resin composition for photolithography - Google Patents

Abstract

[식 (1) 중, X 는 산소 원자, 또는 황 원자, R1 은 수소 원자, 또는 카르복실산기를 가져도 되는 탄소수 1 ∼ 12 의 알킬기, R2 는 수소 원자, 또는 탄소수 1 ∼ 12 의 알킬기, Rf 는 수소의 일부 또는 전부가 불소로 치환되어 있는 탄소수 1 ∼ 12 의 탄화수소기를 나타낸다.]An object of the present invention is to provide a nonionic photoacid generator having high photosensitivity to i-line, excellent compatibility and solubility in a resist solution, and excellent thermal stability. This invention is represented by following General formula (1), The nonionic photo-acid generator (A) characterized by the above-mentioned.

[In formula (1), X is an oxygen atom or a sulfur atom, R1 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms which may have a carboxylic acid group, R2 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, Rf represents a hydrocarbon group having 1 to 12 carbon atoms in which part or all of hydrogen is substituted with fluorine.]

Description

Photoacid generator and resin composition for photolithography

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

BACKGROUND ART Conventionally, in the field of microfabrication typified by the manufacture of semiconductors, a photolithography process using an i-ray having a wavelength of 365 nm as exposure light is widely used.

As a resist material used for a photolithography process, the resin composition containing the polymer which has the tert-butyl ester group of carboxylic acid or the tert- butyl carbonate group of phenol, and a photo-acid generator is used, for example. As the photoacid generator, an ionic photoacid generator such as a triarylsulfonium salt (Patent Document 1), a phenacylsulfonium salt having a naphthalene skeleton (Patent Document 2), and an acid generator having an oximesulfonate structure (Patent Document) 3) and nonionic acid generators such as an acid generator having a sulfonyldiazomethane structure (Patent Document 4) are known. Further, by performing post-exposure heating (PEB), the tert-butyl ester group or tert-butyl carbonate group in the polymer is dissociated by this strong acid to form a carboxylic acid or a phenolic hydroxyl group, and the ultraviolet irradiation part is applied to the alkali developer. ease of dissolution. Pattern formation is performed using this phenomenon.

However, as the photolithography process becomes more microfabricated, the effect of the swelling in which the pattern of the unexposed portion swells by the alkaline developer increases, and it is necessary to suppress the swelling of the resist material.

In order to solve these problems, there has been proposed a method of suppressing the swelling of the resist material by adding an alicyclic skeleton or a fluorine-containing skeleton to the polymer in the resist material to make it hydrophobic.

With respect to hydrophobic materials containing these alicyclic skeletons and fluorine-containing skeletons, the ionic photoacid generator lacks compatibility, and, due to phase separation in the resist material, sufficient resist performance cannot be exhibited, and patterns cannot be formed. there is On the other hand, although a nonionic photo-acid generator has good compatibility with respect to a hydrophobic material, there exists a problem that scum arises in an exposed part in an alkali developing process. In addition, there is a problem of insufficient sensitivity to i-rays and a problem of narrow alignment because it is decomposed by post-exposure heating (PEB) because of insufficient thermal stability.

Japanese Laid-Open Patent Publication No. 50-151997 Japanese Laid-Open Patent Publication No. 9-118663 Japanese Patent Application Laid-Open No. 6-67433 Japanese Laid-Open Patent Publication No. 10-213899

Then, it aims at providing the nonionic photo-acid generator which has high photosensitivity to i line|wire, is excellent in the compatibility and solubility with respect to a resist solution, and is excellent in heat-resistant stability.

MEANS TO SOLVE THE PROBLEM This inventor arrived at this invention, as a result of examining in order to achieve said objective.

That is, this invention is represented by following General formula (1), The nonionic photo-acid generator (A) characterized by the above-mentioned; and a resin composition (Q) for photolithography containing the nonionic photoacid generator (A).

[Formula 1]

[In formula (1), X is an oxygen atom or a sulfur atom, R1 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms which may have a carboxylic acid group, R2 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, Rf represents a hydrocarbon group having 1 to 12 carbon atoms in which part or all of hydrogen is substituted with fluorine.]

Since the nonionic photoacid generator (A) of the present invention has an ether group or a thioether group on the nonionic naphthalimide skeleton to act as an electronic state on the naphthalene ring, very high absorption for i-rays with high sensitivity. By irradiating i-ray|wire by this, a nonionic photo-acid generator (A) can decompose|disassemble easily, and can generate the sulfonic acid which is a strong acid. Moreover, since it has an ester structure in a side chain, it is excellent in the solubility with respect to the solvent which has ester structures, such as PGMEA. Further, since the ether group or the thioether group and the C=O group are close to each other at a distance of 1 carbon number, the orientation to the metal substrate is excellent, and the resist pattern shape is excellent.

Moreover, since it has a naphthalimide skeleton, it has a thermal decomposition temperature of 200 degreeC or more, it is excellent in thermal stability, and can perform post-exposure heating (PEB).

For this reason, the resin composition (Q) for photolithography containing the nonionic photo-acid generator (A) of this invention is excellent in the sensitivity with respect to i line|wire, and compatibility with respect to a resist solution, and solubility are favorable. Moreover, since the allowable range in post-exposure heating (PEB) is wide, it is excellent in workability|operativity.

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

[Formula 2]

[In formula (1), X is an oxygen atom or a sulfur atom, R1 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms which may have a carboxylic acid group, R2 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, Rf represents a hydrocarbon group having 1 to 12 carbon atoms in which part or all of hydrogen is substituted with fluorine.]

Since X is an oxygen atom or a sulfur atom, it can act on the electronic state on the naphthalene ring, resulting in a very high absorption for i-rays.

R1 represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms which may have a carboxylic acid group.

As a C1-C12 alkyl group, a linear alkyl group, a branched alkyl group, and a cyclic alkyl group are mentioned.

Examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decane group, and a dodecane group.

As a branched alkyl group, an isopropyl group, an isobutyl group, t-butyl group, an isopentyl group, 2-ethylhexyl group, etc. are mentioned, for example.

Examples of the cyclic alkyl group include a cyclopentyl group, a cyclohexyl group, and a 3-methylcyclohexyl group.

Examples of the alkyl group having 1 to 12 carbon atoms having a carboxylic acid group include a carboxymethyl group, 2-carboxyethyl group, 4-carboxybutyl group, 2-carboxybutyl group, 6-carboxyhexyl group, 3-carboxyheptane group, 4-carboxycyclohexyl group, 4-carboxymethylcyclohexyl group, etc. are mentioned.

Among these R1, from the viewpoint of solvent solubility and synthesis easiness, preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, particularly preferably a hydrogen atom , and a linear C1-C8 alkyl group.

R2 represents a hydrogen atom or a C1-C12 alkyl group.

Examples of the alkyl group having 1 to 12 carbon atoms include a linear alkyl group, a branched alkyl group, and a cyclic alkyl group. As a linear alkyl group, a branched alkyl group, and a cyclic alkyl group, the thing similar to the above can be used.

Among these R2, from the viewpoint of the shape of the resist pattern, preferably a hydrogen atom and an alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, particularly preferably a hydrogen atom, and tert -It is a butyl group.

Rf is a hydrocarbon group having 1 to 12 carbon atoms in which part or all of hydrogen is substituted with fluorine. Since some or all of the hydrogens in Rf are substituted with fluorine, a strong acid can be generated while having sufficient photosensitivity.

Examples of the group in which part or all of the hydrogen in the hydrocarbon group having 1 to 12 carbon atoms is substituted with fluorine include a linear alkyl group in which the hydrogen atom represented by CxFy is substituted with a fluorine atom (Rf1), a branched chain alkyl group (Rf2), a cycloalkyl group (Rf3), and an aryl group (Rf4).

As the linear alkyl group (Rf1) in which a hydrogen atom is substituted with a fluorine atom, for example, a trifluoromethyl group (x=1, y=3), a pentafluoroethyl group (x=2, y=5), heptafluoropropyl A group (x = 3, y = 7), a nonafluorobutyl group (x = 4, y = 9), a perfluorohexyl group (x = 6, y = 13), and a perfluorooctyl group (x = 8, y=17), etc. are mentioned.

As the branched chain alkyl group (Rf2) in which a hydrogen atom is substituted with a fluorine atom, for example, a perfluoroisopropyl group (x=3, y=7), a perfluoro-tert-butyl group (x=4, y=9) ), and a perfluoro-2-ethylhexyl group (x=8, y=17).

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), A perfluorocyclohexyl group (x=6, y=11), a perfluoro(1-cyclohexyl)methyl group (x=7, y=13), etc. are mentioned.

As the aryl group (Rf4) in which a hydrogen atom is substituted with a fluorine atom, for example, a pentafluorophenyl group (x=6, y=5), and a 3-trifluoromethyltetrafluorophenyl group (x=7, y=7) ) and the like.

Among Rf, from the viewpoint of decomposition of the sulfonic acid ester moiety, deprotection of photoresist, and availability of raw materials, preferably a linear alkyl group (Rf1) in which a hydrogen atom is substituted with a fluorine atom, and an aryl group (Rf4), Preferably, a trifluoromethyl group (x = 1, y = 3, CF ₃ ), a pentafluoroethyl group (x = 2, y = 5, C ₂ F ₅ ), a heptafluoropropyl group (x = 3, y) = 7, C ₃ F ₇ ), a nonafluorobutyl group (x = 4, y = 9, C ₄ F ₉ ), and a pentafluorophenyl group (x = 6, y = 5, C ₆ F ₅ ), especially preferably a methyl group (x = 1, y = 3 , CF 3) trifluoromethyl.

The bonding position of the substituent {-X-CH(R1)-COO-R2} constituting the nonionic photoacid generator (A) of the present invention is not particularly limited, but storage stability (the amine resistance), the quantum yield and molar extinction coefficient can be improved by having it at the 3 position.

The substituent {-X-CH(R1)-COO-R2} bonding position is preferably the 3-position or 4-position from the viewpoint of synthesis and sensitivity.

Although the synthesis method of the nonionic photo-acid generator (A) of this invention will not be specifically limited if the target substance can be synthesize|combined, For example, 3-hydroxy-1,8-naphthalic anhydride and the following general formula (2 ) or a precursor (P1) obtained by reacting a compound of 4-bromo-hydroxy-1,8-naphthalic anhydride with a compound of the following general formula (3) and the like, is reacted with hydroxylamine. It can then be synthesized by reacting the corresponding sulfonic anhydride or sulfonic acid chloride.

[Formula 3]

[In formula (2), R1 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms which may have a carboxylic acid group, R2 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and Hal is chlorine, bromine or iodine. .]

[Formula 4]

[In formula (3), R1 represents a hydrogen atom or a C1-C12 alkyl group which may have a carboxylic acid group, R2 represents a hydrogen atom or a C1-C12 alkyl group. SH represents a thiol group.]

3-hydroxy-1,8-naphthalic anhydride and a compound of the general formula (2), or 4-bromo-hydroxy-1,8-naphthalic anhydride and a compound of the general formula (3) under reaction conditions is 1 to 50 hours at a temperature of -30 to 100°C, and in order to quickly complete the reaction in a good yield, it is preferable to use a reaction solvent and a base catalyst.

Although it does not specifically limit as a reaction solvent, Acetonitrile, tetrahydrofuran, dichloromethane, chloroform, etc. are preferable. Examples of the base catalyst include pyridine, methylmorpholine, dimethylaminopyridine, 2,6-lutidine, triethylamine, imidazole, DBU, sodium hydride, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogencarbonate and the like. This is preferable, and 1-100 mol% is added normally with respect to 3-hydroxy-1,8-naphthalic anhydride.

The molar ratio of 3-hydroxy-1,8-naphthalic anhydride and the compound of the general formula (2), or 4-bromo-hydroxy-1,8-naphthalic anhydride and the compound of the general formula (3), etc. Usually, 1:1-1:4 are carried out.

The nonionic photoacid generator (A) of the present invention obtained by reacting the precursor (P1) with hydroxylamine and then reacting the corresponding sulfonic anhydride or sulfonic acid chloride can be purified by recrystallization with an appropriate organic solvent if necessary. there is.

In order to facilitate dissolution in the resist material, the nonionic photoacid generator (A) of the present invention may be dissolved in advance in a solvent which does not inhibit the reaction.

Examples of the solvent include carbonates (such as propylene carbonate, ethylene carbonate, 1,2-butylene carbonate, dimethyl carbonate, and diethyl carbonate); esters (such as ethyl acetate, ethyl lactate, β-propiolactone, β-butyrolactone, γ-butyrolactone, δ-valerolactone and ε-caprolactone); 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 (such as ethylene glycol monomethyl ether acetate ester, propylene glycol monoethyl ether acetate ester, and diethylene glycol monobutyl ether acetate ester).

When using a solvent, 15-1000 weight part is preferable with respect to 100 weight part of photo-acid generators of this invention, and, as for the usage ratio of a solvent, More preferably, it is 30-500 weight part.

Since the resin composition (Q) for photolithography of this invention contains a nonionic photo-acid generator (A) as an essential component, it performs ultraviolet irradiation and post-exposure heating (PEB), and is a developing solution of an exposed part and an unexposed part. There is a difference in solubility for A nonionic photo-acid generator (A) can be used individually by 1 type or in combination of 2 or more type.

Examples of the resin composition for photolithography (Q) include a mixture of a negative chemical amplification resin (QN) and a nonionic photoacid generator (A); and a mixture of a positive chemical amplification resin (QP) and a nonionic photoacid generator (A).

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 is a resin containing a phenolic hydroxyl group. For example, a novolak resin, polyhydroxystyrene, a copolymer of hydroxystyrene, a copolymer of hydroxystyrene and styrene Copolymer, hydroxystyrene, copolymer of styrene and (meth)acrylic acid derivative, phenol-xylylene glycol condensed resin, cresol-xylylene glycol condensed resin, polyimide containing phenolic hydroxyl group, polyamic acid containing phenolic hydroxyl group , a phenol-dicyclopentadiene condensation resin and the like are used. Among these, novolak resin, polyhydroxystyrene, copolymer of hydroxystyrene, copolymer of hydroxystyrene and styrene, copolymer of hydroxystyrene, styrene and (meth)acrylic acid derivative, phenol-xylylene glycol condensed resin is preferable In addition, these phenolic hydroxyl-containing resin (QN1) may be used individually by 1 type, and may mix and use 2 or more types.

The said novolak resin can be obtained by condensing phenols and aldehydes in presence of a catalyst, for example.

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-trimethylphenol, catechol, resorcinol, pyrogallol, α-naphthol, β-naphthol, and the like.

Moreover, as said aldehydes, formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde, etc. are mentioned.

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

Moreover, the phenolic low molecular weight compound may be contained in the said phenolic hydroxyl group containing resin (QN1) as a part of a 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 -hydroxyphenyl)ethane, 4,4'-{1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene}bisphenol, etc. are mentioned. These phenolic low molecular weight compounds may be used individually by 1 type, and may be used in mixture of 2 or more type.

When the content ratio of this phenolic low molecular weight compound in phenolic hydroxyl group-containing resin (QN1) is 100 weight% of phenolic hydroxyl group-containing resin (QN1), it is preferable that it is 40 weight% or less, More preferably, it is 1 to 30% by weight.

The weight average molecular weight of the phenolic hydroxyl group-containing resin (QN1) is preferably 2000 or more from the viewpoints of resolution, thermal shock property, heat resistance, residual film rate, and the like of the obtained insulating film, and more preferably about 2000 to 20000.

In addition, the content ratio of the phenolic hydroxyl group-containing resin (QN1) in the negative chemical amplification resin (QN) is preferably 30 to 90% by weight, when the entire composition excluding the solvent is 100% by weight. , more preferably 40 to 80% by weight. When the content rate of this phenolic hydroxyl group containing resin (QN1) is 30 to 90 weight%, since the film|membrane formed using the photosensitive insulating resin composition has sufficient developability by aqueous alkali solution, it is preferable.

As a crosslinking agent (QN2), if it is a compound which can bridge|crosslink phenolic hydroxyl-containing resin (QN1) with the strong acid generate|occur|produced from the nonionic photo-acid generator (A), it will not specifically limit.

As the crosslinking agent (QN2), for example, a bisphenol A-based epoxy compound, a bisphenol F-based epoxy compound, a bisphenol S-based epoxy compound, a novolac resin-based epoxy compound, a resol resin-based epoxy compound, a poly(hydroxystyrene)-based epoxy compound, a jade Cetane 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, alkoxy Alkyl group-containing phenol compound, carboxymethyl group-containing melamine resin, carboxymethyl group-containing benzoguanamine resin, carboxymethyl group-containing urea resin, carboxymethyl group-containing phenol resin, carboxymethyl group-containing melamine compound, carboxymethyl group-containing benzoguanamine compound, carboxymethyl group-containing urea compound and a carboxymethyl group-containing phenol compound.

Among these crosslinking agents (QN2), a methylol group-containing phenol compound, a methoxymethyl group-containing melamine compound, a methoxymethyl group-containing phenol compound, a methoxymethyl group-containing glycoluril compound, a methoxymethyl group-containing urea compound, and an acetoxymethyl group-containing phenol compound are preferable. and more preferably a melamine compound containing a methoxymethyl group (eg, hexamethoxymethylmelamine, etc.), a glycoluril compound containing a methoxymethyl group, and a urea compound containing a methoxymethyl group. Methoxymethyl group-containing melamine compounds are trade names such as CYMEL300, CYMEL301, CYMEL303, CYMEL305 (manufactured by Mitsui Cyanamide Co., Ltd.), and glycoluril compounds containing methoxymethyl group are trade names such as CYMEL1174 (manufactured by Mitsui Cyanamide Co., Ltd.) In addition, a urea compound containing a methoxymethyl group is marketed under a trade name such as MX290 (manufactured by Sanwa Chemical Co., Ltd.).

Content of a crosslinking agent (QN2) is 5-60 mol% normally with respect to all the acidic functional groups in phenolic hydroxyl-containing resin (QN1) from a viewpoint of the fall of a residual film rate, meandering and swelling of a pattern, and developability, Preferably It is 10-50 mol%, More preferably, it is 15-40 mol%.

As the positive chemical amplification resin (QP), a part or all of the hydrogen atoms of the acidic functional group in the alkali-soluble resin (QP1) containing at least one acidic functional group such as a phenolic hydroxyl group, a carboxyl group, or a sulfonyl group is an acid dissociable group and protective group-introducing resin (QP2) substituted with .

In addition, an acid-dissociable group is a group which can dissociate in presence of the strong acid which generate|occur|produced from the nonionic photo-acid generator (A).

Protecting group-introduced resin (QP2) itself is insoluble in alkali or sparingly soluble in alkali.

Examples of the alkali-soluble resin (QP1) include phenolic hydroxyl group-containing resin (QP11), carboxyl group-containing resin (QP12), and sulfonic acid group-containing resin (QP13).

As phenolic hydroxyl-containing resin (QP11), the thing similar to the said hydroxyl-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, it is obtained by vinyl polymerization of a carboxyl group-containing vinyl monomer (Ba) and, if necessary, a hydrophobic group-containing vinyl monomer (Bb).

As the carboxyl group-containing vinyl monomer (Ba), for example, an unsaturated monocarboxylic acid [(meth)acrylic acid, crotonic acid, cinnamic acid, etc.], an unsaturated polyvalent (2-tetravalent) carboxylic acid [(anhydride) maleic acid, it Conic acid, fumaric acid and citraconic acid], unsaturated polyvalent alkyl carboxylate (alkyl group having 1 to 10 carbon atoms) esters [maleic acid monoalkyl ester, fumaric acid monoalkyl ester, and citraconic acid monoalkyl ester], and salts thereof [Alkali metal salts (sodium salt, potassium salt, etc.), alkaline earth metal salt (calcium salt, magnesium salt, etc.), amine salt, ammonium salt, etc.] are mentioned.

Among these, an unsaturated monocarboxylic acid is preferable from a viewpoint of polymerizability and availability, and (meth)acrylic acid is more preferable.

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

As (meth)acrylic acid ester (Bb1), for example, the C1-C20 alkyl (meth)acrylate of an 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] and alicyclic group-containing (meth) acrylate [dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, etc.], etc. are mentioned.

As the aromatic hydrocarbon monomer (Bb2), for example, a hydrocarbon monomer having a styrene skeleton [for example, styrene, α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, phenyl styrene, cyclohexyl styrene and benzyl styrene] and vinyl naphthalene.

In the carboxyl group-containing resin (QP12), the injection monomer molar ratio of (Ba)/(Bb) is usually 10 to 100/0 to 90, and from the viewpoint of developability, preferably 10 to 80/20 to 90, more preferably It is preferably 25 to 85/15 to 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, it is obtained by vinyl polymerization of a sulfonic acid group-containing vinyl monomer (Bc) and, if necessary, a hydrophobic group-containing vinyl monomer (Bb). .

As a hydrophobic group containing vinyl monomer (Bb), the thing similar to the above can be used.

Examples of the sulfonic acid group-containing vinyl monomer (Bc) include vinylsulfonic acid, (meth)allylsulfonic acid, styrenesulfonic acid, α-methylstyrenesulfonic acid, 2-(meth)acryloylamide-2-methylpropanesulfonic acid, and these salts may be mentioned. Examples of the salt include alkali metal (sodium and potassium, etc.) salts, alkaline earth metal (calcium and magnesium, etc.) salts, primary to tertiary amine salts, ammonium salts and quaternary ammonium salts.

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

The HLB value of the alkali-soluble resin (QP1) has a different preferred range depending on the resin skeleton of the alkali-soluble resin (QP1), but is preferably 4 to 19, more preferably 5 to 18, particularly preferably 6 to 17 am.

When developing as HLB value is 4 or more, developability is still more favorable, and the water resistance of hardened|cured material is still more favorable as it is 19 or less.

In addition, the HLB value in this invention is an HLB value by the Oda method, a hydrophilicity-hydrophobicity balance value is said, and it can calculate from the ratio of the organic value of an organic compound, and the inorganic value.

HLB ≒ 10 × inorganic/organic

In addition, the value of inorganic property and the value of organic property are page 501 of the document "Synthesis of surfactant and its application" (published by Maki Bookstore, by Oda, Teramura); Alternatively, it is described in detail on page 198 of "Introduction to New Surfactants" (by Takehiko Fujimoto, published by Sanyo Chemical Industry Co., Ltd.).

Examples of the acid dissociable group in the protecting group-introduced resin (QP2) include a substituted methyl group, a 1-substituted ethyl group, a 1-branched alkyl group, a silyl group, a germanyl group, an alkoxycarbonyl group, an acyl group, and a cyclic acid dissociable group. can These may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the 1-substituted methyl group include a methoxymethyl group, a methylthiomethyl group, an ethoxymethyl group, an ethylthiomethyl group, a methoxyethoxymethyl group, a benzyloxymethyl group, a benzylthiomethyl group, a phenacyl group, a bromophenacyl group, and a methoxymethyl group. Toxyphenacyl group, methylthiophenacyl group, α-methylphenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, bromobenzyl group, nitrobenzyl group, methoxybenzyl group, methylthiobenzyl group, E Toxybenzyl group, ethylthiobenzyl group, piperonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, n-propoxycarbonylmethyl group, i-propoxycarbonylmethyl group, n-butoxycarbonylmethyl group, tert -butoxycarbonylmethyl group, etc. are mentioned.

Examples of the 1-substituted ethyl group include 1-methoxyethyl group, 1-methylthioethyl group, 1,1-dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, and 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-butoxycarbonylethyl group, etc. are mentioned.

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

Examples of the silyl group include a trimethylsilyl group, an ethyldimethylsilyl group, a methyldiethylsilyl group, a triethylsilyl group, an i-propyldimethylsilyl group, a methyldi-i-propylsilyl group, and a tri-i-propylsilyl group. and tricarbylsilyl groups such as group, tert-butyldimethylsilyl group, methyldi-tert-butylsilyl group, tri-tert-butylsilyl group, phenyldimethylsilyl group, methyldiphenylsilyl group, and triphenylsilyl group. there is.

As the germanyl group, for example, a trimethylgermyl group, an ethyldimethylgermyl group, a methyldiethylgermyl group, a triethylgermyl group, an isopropyldimethylgermyl group, a methyldi-i-propylgermyl group, and a tri-i-propylgermyl group. and tricarbylgermyl groups such as wheat, tert-butyldimethylgermyl, methyldi-tert-butylgermyl, tri-tert-butylgermyl, phenyldimethylgermyl, methyldiphenylgermyl, and triphenylgermyl. can

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

As the acyl group, for example, an acetyl group, a propionyl group, a butyryl group, a heptanoyl group, a hexanoyl group, a valeryl group, a pivaloyl group, an isovaleryl group, a lauroyl group, a myristoyl group, a palmitoyl group, a stearoyl group , oxalyl group, malonyl group, succinyl group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelayl group, sebacoyl group, acryloyl group, propioloyl group, methacryloyl group, chloro Tonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconyl group, camphoroyl group, benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluyl group, hydroatropoyl group , an atropoyl group, a cinnamoyl group, a furoyl group, a tenoyl group, a nicotinoyl group, an isonicotinoyl group, a p-toluenesulfonyl group, and a 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, and a tetrahydrothio group. Pyranyl group, tetrahydrothiofuranyl 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, tetra Hydrofuranyl group, tetrahydrothiopyranyl group, tetrahydrothiofuranyl group, etc. are preferable.

The introduction rate of acid dissociable groups in the protecting group introduction resin (QP2) {ratio of the number of acid dissociable groups to the total number of unprotected acid functional groups and acid dissociable groups in the protecting group introduction resin (QP2)} However, depending on the kind of alkali-soluble resin into which the group is introduced, it cannot be defined uniformly, but it is preferably 10 to 100%, more preferably 15 to 100%.

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

In addition, the ratio (Mw/Mn) of the Mw of the protecting group-introducing resin (QP2) to the polystyrene reduced number average molecular weight (hereinafter referred to as “Mn”) measured by gel permeation chromatography (GPC) is usually 1 to 10, Preferably it is 1-5.

As for content of the nonionic photo-acid generator (A) based on the weight of solid content of the resin composition (Q) for photography, 0.001-20 weight% is preferable, More preferably, 0.01-15 weight% is especially preferable. is 0.05 to 7% by weight.

When it is 0.001 weight% or more, the sensitivity with respect to an ultraviolet-ray can be exhibited more favorably, and when it is 20 weight% or less, the physical property of an insoluble part with respect to an alkali developing solution can be exhibited further more favorably.

The resist using the resin composition (Q) for photography of the present invention is, for example, a resin solution dissolved in a predetermined organic solvent (dissolved and dispersed in the case of containing inorganic fine particles) by spin coating, curtain coating, roll It can be formed by coating, spray coating, screen printing, etc. using a well-known method, after apply|coating to a board|substrate, and drying a solvent by heating or hot air spraying.

The organic solvent for dissolving the resin composition (Q) for photography is not 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. For example, N-methylpyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, toluene, ethanol, cyclohexanone, methanol, methyl ethyl ketone, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl Well-known solvents, such as ether acetate, acetone, and xylene, can be used.

Among these solvents, those having a boiling point of 200° C. or less from the viewpoint of drying temperature and the like (toluene, ethanol, cyclohexanone, methanol, methyl ethyl ketone, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate, acetone and xylene) is preferable, and can also be used individually or in combination of 2 or more types.

When using an organic solvent, although the compounding quantity of a solvent is not specifically limited, Based on the weight of solid content of the resin composition (Q) for photography, 30 to 1,000 weight% is preferable normally, More preferably, 40 to 900 % by weight, particularly preferably 50 to 800% by weight.

Although the drying conditions of the resin solution after application|coating change with the solvent to be used, Preferably it is carried out at 50-2000 degreeC in the range of 2-30 minutes, The residual solvent amount (weight of the resin composition (Q) for photography after drying) %) and the like.

After forming a resist on a board|substrate, light irradiation in the shape of a wiring pattern is performed. Then, after performing post-exposure heating (PEB), alkali development is performed and a wiring pattern is formed.

As a method of light irradiation, the method of exposing a resist with actinic light through the photomask which has a wiring pattern is mentioned. There will be no restriction|limiting in particular as actinic light used for light irradiation, if the nonionic photo-acid generator (A) in the resin composition (Q) for photography of this invention can be decomposed|disassembled.

Examples of active light include low pressure mercury lamps, medium pressure mercury lamps, high pressure mercury lamps, ultra-high pressure mercury lamps, xenon lamps, metal halide lamps, electron beam irradiators, X-ray irradiators, lasers (argon lasers, dye lasers, nitrogen lasers, LEDs, helium cadmium lasers, etc.) ), etc. Among these, a high pressure mercury lamp and an ultra high pressure mercury lamp are preferable.

As a temperature of post-exposure heating (PEB), it is 40-200 degreeC normally, Preferably it is 50-190 degreeC, More preferably, it is 60-180 degreeC. If the temperature is less than 40 ° C, the deprotection reaction or the crosslinking reaction cannot be sufficiently performed, so the difference in solubility between the ultraviolet irradiated part and the ultraviolet ray non-irradiated part is insufficient to form a pattern, and if it is higher than 200 ° C, productivity is lowered.

As a heating time, control of time and temperature is difficult when it is 0.5-120 minutes normally, and when it exceeds 120 minutes, there exists a problem that productivity falls.

As a method of performing alkali development, the method of dissolving and removing in a wiring pattern shape using an alkali developing solution is mentioned. There will be no restriction|limiting in particular as an alkaline developing solution, if it is the conditions which a difference produces the solubility of the ultraviolet-ray irradiation part of the resin composition (Q) for photography, and an ultraviolet-ray unirradiated part.

Examples of the alkaline developer include an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous sodium hydrogen carbonate solution, and an aqueous solution of a tetramethylammonium salt.

These alkaline developing solutions may add a water-soluble organic solvent. Examples of the water-soluble organic solvent include methanol, ethanol, isopropyl alcohol, tetrahydrofuran and N-methylpyrrolidone.

As a developing method, although there exist a dip system using an alkali developer, a shower system, and a spray system, the method of a spray system is preferable.

The temperature of a developing solution becomes like this. Preferably it is used at 25-40 degreeC. The development time is appropriately determined according to the thickness of the resist.

Example

Hereinafter, although an Example and a comparative example demonstrate this invention further, this invention is not limited to these. Hereinafter, unless otherwise specified, % represents weight %, and a part represents weight part.

<Example 1>

3 After dispersing 21 parts of 3-hydroxy-1,8-naphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) and 27 parts of potassium carbonate in 400 parts of acetonitrile in each flask, tert-butyl chloroacetate (manufactured by Tokyo Chemical Industry Co., Ltd.) 30 parts were thrown in, and it was made to react at 75 degreeC for 6 hours.

Then, after filtering off potassium carbonate, 18 parts of 50% hydroxylamine aqueous solution (made by Tokyo Chemical Industry Co., Ltd.) was added dropwise, and it was made to react at room temperature for 2 hours. After completion of the reaction, the reaction solution was added to ion-exchanged water, and then hydrochloric acid was added until pH 5 was reached. After stirring for a while, the precipitate was collected by filtration, dried under reduced pressure at 70°C, and a precursor of a pale yellow solid was obtained.

After dissolving the dried precursor in 500 parts of dichloromethane and 20 parts of pyridine, it was cooled to 10°C, and 42 parts of trifluoromethanesulfonic anhydride (manufactured by Mitsubishi Material Electron Chemicals, EF-18) was added dropwise. After dropwise addition and reaction at room temperature for 1 hour, washing with ion-exchanged water was performed. Crystals were deposited by concentrating the reaction solution after washing with water and adding methanol. This crystal was collected by filtration and dried under reduced pressure at 50°C to obtain a nonionic photoacid generator (A-1) of the present invention.

<Example 2>

The same operation as in Example 1 was carried out except that 30 parts of tert-butyl chloroacetate was changed to 40 parts of 2-bromobutyrate ethyl 2-bromobutyrate (manufactured by Tokyo Chemical Industry Co., Ltd.), and the nonionic photoacid generator of the present invention (A-2) got

<Example 3>

The same operation as in Example 1 was carried out except that 30 parts of tert-butyl chloroacetate was changed to 40 parts of methyl 2-bromohexanoate (manufactured by Tokyo Chemical Industry Co., Ltd.), and the nonionic photoacid generator of the present invention (A-3 ) was obtained.

<Example 4>

21 parts of 3-hydroxy-1,8-naphthalic anhydride, 28 parts of 4-bromo-1,8-naphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.), 27 parts of potassium carbonate, 11 parts of triethylamine, and tert-chloroacetic acid Except having changed 30 parts of butyl into 16 parts of butyl thioglycolate (made by Tokyo Chemical Industry Co., Ltd.), operation similar to Example 1 was performed and the nonionic photo-acid generator (A-4) of this invention was obtained.

<Example 5>

The same operation as in Example 4 was carried out except that 16 parts of butyl thioglycolate was changed to 22 parts of 2-ethylhexyl thioglycolate (manufactured by Tokyo Chemical Industry Co., Ltd.), and the nonionic photoacid generator of the present invention (A-5) got

<Example 6>

The same operation as in Example 4 was carried out except that 16 parts of butyl thioglycolate was changed to 16 parts of thiomalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 11 parts of triethylamine to 35 parts, and the nonionic photoacid generator of the present invention (A -6) was obtained.

<Example 7>

The same operation as in Example 4 was carried out except that 16 parts of butyl thioglycolate was changed to 12 parts of thiolactic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 11 parts of triethylamine was changed to 22 parts, and the nonionic photoacid generator of the present invention (A -7) was obtained.

<Example 8>

10 parts of the photoacid generator (A-1) obtained in Example 1 was dissolved in 100 parts of ethyl acetate and 50 parts of a hydrogen chloride/ethyl acetate solution (about 4 mol/L) (manufactured by Wako Pure Chemical Industries, Ltd.) at 75°C It was made to react for 6 hours, and the ester group was removed. Then, after removing an acid with water washing, the nonionic photo-acid generator (A-8) of this invention was obtained by removing the solvent under reduced pressure.

<Example 9>

3 In each flask, 40 parts of 2-bromobutyric acid, 4 parts of dimethylaminopyridine, and 80 parts of tert-butyl alcohol were dissolved in 800 parts of dichloromethane, and then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide 50 parts of hydrochloric acid salt was thrown in, and it was made to react at room temperature for 3 hours. Then, after washing with a 1% aqueous hydrochloric acid solution, the solvent was removed under reduced pressure to obtain tert-butyl bromobutyrate.

Next, the same operation as in Example 1 was carried out except that 30 parts of tert-butyl chloroacetate was changed to 40 parts of tert-butyl 2-bromobutyrate obtained above, and the nonionic photoacid generator of the present invention (A -9) was obtained.

<Example 10>

Except having changed 2-bromobutyric acid into 2-bromohexanoic acid, operation similar to Example 9 was performed and the nonionic photo-acid generator (A-10) of this invention was obtained.

<Example 11>

Except having changed the photo-acid generator (A-1) into the photo-acid generator (A-9) obtained in Example 9, operation similar to Example 8 was performed, and the nonionic photo-acid generator (A-) of this invention 11) was obtained.

<Example 12>

Except having changed the photo-acid generator (A-1) into the photo-acid generator (A-11) obtained in Example 11, operation similar to Example 8 was performed, and the nonionic photo-acid generator (A-) of this invention 12) was obtained.

<Comparative Example 1>

1,8-naphthalic acid imide trifluoromethanesulfonate represented by the following formula (4) (manufactured by Aldlich) was used as it was.

[Formula 5]

<Comparative Example 2>

3-methoxy-1,8-naphthalic imide p-toluenesulfonic acid represented by the following formula (5) was prepared in J. Chem. Soc. (C), 1966, p523 was synthesized and used.

[Formula 6]

<Examples 1 to 9, Comparative Examples 1 to 2>

As performance evaluation of a photo-acid generator, the nonionic photo-acid generators (A-1) - (A-9) obtained in Examples 1-9, and the nonionic photo-acid generators (A'-1) for a comparison - ( The molar extinction coefficient, photodegradation rate, resist sensitivity, and solvent solubility of A'-2) were evaluated by the following methods, and the results are shown in Table 1.

<Molar extinction coefficient>

The synthesized photo-acid generator was diluted to 0.025 mmol/L with acetonitrile, and a cell length of 1 cm in the range of 200 nm to 500 nm using an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, UV-2550). Absorbance was measured. _{The molar extinction coefficient (ε 365} ) of the i-line (365 nm) was calculated from the following formula.

ε ₃₆₅ (L mol ^-1 cm ^-1 ) = A ₃₆₅ /(0.00025 mol/ℓ × 1 cm)

[Wherein, A ₃₆₅ represents the absorbance at 365 nm.]

<Photodegradation rate>

The 0.025 mmol/L solution adjusted above was placed in a test tube having a diameter of 1 cm and irradiated with light at 50 mJ/cm 2 (365 nm). The photo-decomposition rate of the photo-acid generator was computed from the area ratio of liquid chromatography (LC) before and behind light irradiation of this solution.

Photodegradation rate (%) = (S ₀ − S ₁ )/S ₀ × 100

S ₀ : LC peak area of the photo-acid generator before light irradiation

S ₁ : LC peak area of the photo-acid generator after light irradiation

<resist sensitivity>

A resist solution prepared with 0.2 parts of a nonionic photoacid generator, 100 parts of an ESCAP-based polymer (hydroxystyrene and t-butyl acrylate copolymer), and 900 parts of propylene glycol monomethyl ether acetate (PGMEA) was placed on a silicon wafer. After spin coating, the resist film with a film thickness of 6 micrometers was obtained by drying at 100 degreeC for 4 minutes.

UV irradiation device (manufactured by Oak Corporation, HMW-661F-01) was used for this resist film, and the wavelength was limited by an L-34 filter (manufactured by Kenko Optical, Inc., a filter that cuts light below 340 nm) A predetermined amount of ultraviolet light was exposed on the entire surface. In addition, the cumulative exposure amount was measured at a wavelength of 365 nm. Subsequently, after performing an after-baking at 110 degreeC for 90 second, it developed by dipping for 60 second in 2.38% TMAH aqueous solution. From the minimum exposure dose (Eth) at which the resist film of this exposed portion was completely removed, the resist sensitivity was evaluated according to the following criteria.

○: Minimum exposure dose of 50 mJ/cm2 or less

△: Minimum exposure dose exceeding 50 mJ/cm2 and less than or equal to 100 mJ/cm2

×: The minimum exposure amount exceeds 100 mJ/cm2

<Solvent solubility>

The synthesized photo-acid generator was placed in a 0.3 g test tube, and 0.2 to 0.5 g of propylene glycol monomethyl ether acetate (PGMEA) was added at a temperature of 25° C. until the photo-acid generator was completely dissolved. Solid content concentration at the time of this melt|dissolution was made into solvent solubility. Moreover, when it did not melt|dissolve completely even if it added 30 g, it evaluated that it does not melt|dissolve.

Since the nonionic photoacid generator of the present invention has a high molar extinction coefficient with respect to i-ray (365 nm) and is excellent in photodecomposition rate, it is useful as a thin film resist application. Moreover, the solubility with respect to a solvent is 5 % or more, and it turns out that it has sufficient performance in order to use it as a photoresist.

On the other hand, in Comparative Example 1 comprising a naphthylimide skeleton having no substituent, absorption to the i-line is insufficient, and the naphthyl skeletons are easily aligned with each other and crystallinity is increased, so the solubility in a solvent is too low. it can be seen that Moreover, in Comparative Example 2 in which the hydrogen atom of Rf is not substituted with fluorine, it is found that the absorption with respect to the i line is sufficient, but the photodecomposition rate is low. Moreover, since a substituent is a methoxy group and does not have sufficient polarity and size, it turns out that solvent solubility is insufficient.

Industrial Applicability

The nonionic photoacid generator (A) of the present invention has high photosensitivity to i-line, is excellent in compatibility and solubility in a resist solution, and is excellent in heat resistance stability. It is useful as a photolithography material of

Claims (4)

It is represented by following General formula (1), The nonionic photo-acid generator (A) characterized by the above-mentioned.

[In formula (1), X is an oxygen atom or a sulfur atom, R1 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms which may have a carboxylic acid group, R2 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, Rf represents a hydrocarbon group having 1 to 12 carbon atoms in which part or all of hydrogen is substituted with fluorine.] The method of claim 1,
In the formula (1), Rf is _{CF 3, C 2 F 5,} C 3 F 7, C 4 F 9, C ₆ F ₅ or the non-ionic photo-acid generator (A). 3. The method according to claim 1 or 2,
Nonionic photo-acid generator (A) whose R<2> is a hydrogen atom or a C1-C4 alkyl group in General formula (1). The resin composition (Q) for photolithography containing the nonionic photo-acid generator (A) in any one of Claims 1-3.