JP2010091691A - Positive radiation-sensitive resin composition - Google Patents

Abstract

で表される構造単位を有する重合体、酸発生剤を含有するポジ型感放射線性樹脂組成物。
【選択図】なしProvided is a positive radiation-sensitive resin composition that can suppress the occurrence of cracks when plating is performed on a substrate on which a resist pattern is formed.
Formula (I)

A positive radiation sensitive resin composition containing a polymer having a structural unit represented by formula (1) and an acid generator.
[Selection figure] None

Description

  The present invention relates to a positive radiation sensitive resin composition useful for the production of micromachines, semiconductor packages, printed boards and the like.

  The method of forming a metal pattern on a substrate of silicon, glass, etc. includes the manufacture of micromachines, the formation of various metal bumps such as gold, silver, copper, nickel and solder in a semiconductor package, the connection parts and wiring patterns of metal posts, etc. It is useful for forming a connection part and a wiring pattern in a printed circuit board. For example, by forming a resist of a radiation sensitive resin with a film thickness of 1 μm or more on a substrate, forming a resist pattern on the substrate by a lithography technique, plating the substrate, and then removing the resist pattern from the substrate A plating pattern can be formed on the substrate. However, when a plating process is performed on a substrate on which a resist pattern is formed, there is a problem that cracks are generated in the resist pattern due to internal stress of the resist film or stress accompanying growth of plating.

Chemically amplified positive resist composition for forming a resist having a film thickness of 5 to 150 μm, containing a polymer obtained by reacting an alkenyl ether with a resin obtained by polycondensation of phenols and aldehydes under an acidic catalyst A thing is known (patent document 1). However, when a resist pattern is formed using the chemically amplified positive resist composition specifically disclosed in Patent Document 1 and then plated, it is difficult to sufficiently suppress the occurrence of cracks in the resist pattern. .
JP 2006-178423 A

  An object of the present invention is to expose a resist formed by coating on a substrate, to perform a heat treatment after the exposure, and to form a good resist pattern when developing after the heat treatment, and the resist pattern An object of the present invention is to provide a positive-type radiation-sensitive resin composition or the like that can suppress the occurrence of cracks in the resist pattern when a plating process is performed on the substrate on which is formed.

The present invention provides the following (1) to (5).
(1) Formula (I)

(In the formula, R ¹ represents alkyl having 1 to 8 carbon atoms, R ² represents a hydrogen atom, substituted or unsubstituted alkyl, substituted or unsubstituted alicyclic saturated hydrocarbon group, substituted or unsubstituted aryl, or Represents substituted or unsubstituted aralkyl, R ³ represents substituted or unsubstituted alkyl, substituted or unsubstituted alicyclic saturated hydrocarbon group, substituted or unsubstituted aryl, or substituted or unsubstituted aralkyl, and n represents A compound that represents an integer of 0 to ³ and each R ³ may be the same or different when n is 2 or 3, and a compound that generates an acid upon irradiation with radiation And a positive-type radiation-sensitive resin composition containing an organic solvent.
(2) The positive radiation sensitive resin composition according to (1), wherein the polymer having the structural unit represented by the formula (I) has a weight average molecular weight of 1000 to 100,000.
(3) A step of exposing a resist formed by applying the positive radiation-sensitive resin composition according to (1) or (2) on a substrate, a step of performing a heat treatment after the exposure, and the heat treatment And a step of developing the resist pattern later.
(4) The method for forming a resist pattern according to (3), wherein the film thickness of the resist formed by applying the positive radiation sensitive resin composition on the substrate is 1-150 μm.
(5) A plating pattern comprising a step of plating a substrate having a resist pattern formed by the method according to (3) or (4), and a step of removing the resist from the substrate subjected to the plating treatment Forming method.

  According to the present invention, a resist formed by coating on a substrate is exposed, a heat treatment is performed after the exposure, and a good resist pattern can be formed when developing after the heat treatment, and the resist pattern is formed. The positive radiation sensitive resin composition etc. which can suppress generation | occurrence | production of the crack in this resist pattern when carrying out the plating process to this said board | substrate can be provided.

Hereinafter, the polymer having the structural unit represented by the formula (I) may be referred to as the polymer (I).
In the definition of each group in the formula, examples of the alkyl include linear or branched alkyl having 1 to 18 carbon atoms, specifically, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, Examples include sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, octadecyl and the like.

  Examples of the alicyclic saturated hydrocarbon in the alicyclic saturated hydrocarbon group include, for example, a cycloalkane having 3 to 12 carbon atoms, a bridged cyclic saturated hydrocarbon having 7 to 12 carbon atoms, and spiro saturation having 7 to 12 carbon atoms. Specific examples include hydrocarbons such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, cyclododecane, adamantane, tricyclodecane, tetracyclododecane, norbornane, isonorbornane, spiroheptane. , Spirooctane and the like.

Examples of aryl include aryl having 6 to 14 carbon atoms, and specific examples include phenyl and naphthyl.
Examples of aralkyl include aralkyl having 7 to 15 carbon atoms, and specific examples include benzyl, phenethyl, naphthylmethyl, naphthylethyl, and the like.
Examples of the alkyl substituent include hydroxy, alkoxy, alkylthio, aryloxy, arylthio, alkanoyl, mercapto, oxo, cyano, nitro, formyl, halogen atom, alkoxycarbonyl and the like. The alkyl part of alkoxy, alkylthio and alkoxycarbonyl is as defined above for alkyl. The aryl moieties of aryloxy and arylthio are as defined above for aryl. Examples of alkanoyl include linear or branched alkanoyl having 2 to 7 carbon atoms, and specific examples include acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, hexanoyl, heptanoyl and the like. . Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.

  Examples of the alicyclic saturated hydrocarbon group, aryl and aralkyl substituents include alkyl, hydroxy, alkoxy, alkylthio, aryloxy, arylthio, alkanoyl, mercapto, cyano, nitro, halogen atom, alkoxycarbonyl and the like. Here, the alkyl part of alkyl, alkoxy, alkylthio and alkoxycarbonyl, the aryl part of aryloxy and arylthio, the alkanoyl and the halogen atom are as defined above.

R ¹ preferably has 1 to 4 carbon atoms.
R ² is preferably a hydrogen atom.
n is preferably 0 or 1, and when n is 1, R ³ is preferably alkyl having 1 to 6 carbon atoms, and more preferably methyl. Here, examples of the alkyl having 1 to 6 carbon atoms include those having 1 to 6 carbon atoms among the groups listed above as alkyl.

  The polymer (I) is, for example, of the formula (II)

(Wherein R ² , R ³ and n are as defined above) and a alkenyl ether corresponding to a polymer [hereinafter also referred to as polymer (II)]. , Or simply an alkenyl ether) or a hydrogen halide addition compound thereof (hereinafter sometimes simply referred to as a hydrogen halide addition compound). Here, the halogen has the same meaning as described above, and the same applies to the following.

The equivalent ratio (molar ratio) between the phenolic hydroxyl group in the polymer (II) and the corresponding alkenyl ether or its hydrogen halide addition compound is preferably 1: 0.03 to 1: 2.
The reaction temperature is preferably 0 to 150 ° C, more preferably 0 to 100 ° C, and even more preferably 0 to 50 ° C.

  In the reaction, an acid catalyst may be used. Examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, and organic acids such as methanesulfonic acid and p-toluenesulfonic acid. Of these, p-toluenesulfonic acid is preferred. Two or more acid catalysts may be combined. Although the usage-amount of this acid catalyst is not specifically limited, It is 0.0001-0.5 equivalent (molar ratio) with respect to the phenolic hydroxyl group in the polymer which has a structural unit of a formula (II). Preferably, it is 0.001-0.1 equivalent (molar ratio).

In the reaction, an organic solvent may be used. Examples of the organic solvent include hydrocarbon solvents such as hexane, toluene and xylene, ether solvents such as dioxane and tetrahydrofuran, and ketone solvents such as acetone, ethyl methyl ketone and isobutyl methyl ketone. You may use these individually or in mixture of 2 or more types.
Many of the polymers (II) are available as commercial products. For example, phenol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2 Phenols such as 1,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,4-trimethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, , Polycondensation with aldehydes such as formaldehyde, benzaldehyde, furfural and acetaldehyde in the presence of acidic catalysts (for example, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, organic acids such as p-toluenesulfonic acid). May be manufactured. The above phenols and aldehydes may be used alone or in admixture of two or more.

  Specific examples of the alkenyl ether include, for example, 1-methoxy-2-ethylhexene, 1-ethoxy-2-ethylhexene, 1-propoxy-2-ethylhexene, 1-isopropoxy-2-ethylhexene, 1-butoxy. 2-ethylhexene, 1-isobutoxy-2-ethylhexene, 1- (tert-butoxy) -2-ethylhexene, 1-pentyloxy-2-ethylhexene, 1-isopentyloxy-2-ethylhexene, 1 -Neopentyloxy-2-ethylhexene, 1- (tert-pentyloxy) -2-ethylhexene, 1-hexyloxy-2-ethylhexene, 1-isohexyloxy-2-ethylhexene, 1- (2- Ethylhexyloxy) -2-ethylhexene, 1-heptyloxy-2-ethylhexene 1-octyloxy-2-ethyl-hexene, and the like.

  The alkenyl ether can be obtained by production according to a known method, for example, the method described in International Publication No. 2006/115265 pamphlet. Specifically, for example, a first step of obtaining an acetal compound by reacting 2-ethylhexanal and an alcohol in the presence of an acidic catalyst such as p-toluenesulfonic acid at 0 to 150 ° C. for 0.5 to 5 hours. Then, the acetal compound is mixed with an organic acid (for example, hydrochloric acid, sulfuric acid, phosphoric acid, p-toluenesulfonic acid, etc.) and an organic base (for example, an organic amine such as n-propylamine, diethylamine, triethylamine, etc., or a complex such as pyridine). The alkenyl ether can be obtained by performing the second step of obtaining an alkenyl ether by treatment at 0 to 150 ° C. for 0.5 to 5 hours in the presence of a ring compound or the like.

  An organic solvent may be used in the reaction in the first step and the second step. Examples of the organic solvent include hydrocarbon solvents such as hexane, toluene and xylene, ether solvents such as dioxane and tetrahydrofuran, aprotic such as N, N-dimethylacetamide, N, N-dimethylformamide and dimethylsulfoxide. Examples include polar solvents. You may use these individually or in mixture of 2 or more types.

  As alcohols, methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutanol, tert-butyl alcohol, n-pentanol, isopentanol, neopentanol, tert-pentyl alcohol, n-hexanol, Examples include isohexanol, 2-ethylhexanol, n-heptanol, and n-octanol.

  It is preferable that the usage-amount of alcohol is 1-10 equivalent (molar ratio) with respect to 2-ethylhexanal. It is preferable that the usage-amount of an acidic catalyst is 0.0001-0.2 equivalent (molar ratio) with respect to 2-ethylhexanal. In the first step, after the reaction, the acetal compound may be purified by methods usually used in organic synthetic chemistry (such as various chromatographic methods and distillation methods).

  The amount of the organic acid used is preferably 0.0001 to 0.2 equivalent (molar ratio) with respect to the acetal compound. The amount of the organic base used is preferably 0.00005 to 0.2 equivalent (molar ratio) with respect to the acetal compound. In the second step, the alkenyl ether may be purified by a method usually used in organic synthetic chemistry (various chromatographic methods, distillation methods, etc.) after the reaction.

Examples of the hydrogen halide addition compound include compounds in which a halogen is added to the 1-position of the double bond of the alkenyl ether exemplified above and a hydrogen atom is added to the 2-position.
A hydrogen halide addition compound can be obtained by manufacturing according to a well-known method, for example, the method etc. of the international publication 2005/023880 pamphlet. Specifically, for example, a hydrogen halide addition compound can be obtained by reacting alkenyl ether and gaseous hydrogen halide at 0 to 20 ° C. for 0.5 to 5 hours. Here, the alkenyl ether has the same meaning as described above. Examples of the hydrogen halide include hydrogen chloride, hydrogen bromide, hydrogen iodide, etc. Among them, hydrogen chloride is preferable. The amount of hydrogen halide used is preferably 0.8 to 10 equivalents (molar ratio) with respect to the alkenyl ether. In the reaction, an organic solvent may be used. Examples of the organic solvent include hydrocarbon solvents such as hexane, toluene and xylene, ether solvents such as dioxane and tetrahydrofuran, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, N, N-dimethylacetamide, N , N-dimethylformamide, aprotic polar solvents such as dimethyl sulfoxide, and the like. The obtained hydrogen halide addition compound may be purified by methods commonly used in organic synthetic chemistry (various chromatographic methods, recrystallization methods, distillation methods, etc.).

The weight average molecular weight of the polymer having the structural unit represented by the formula (I) is preferably 1000 to 100,000, more preferably 1000 to 50,000.
Examples of compounds that generate an acid upon irradiation with radiation (hereinafter sometimes referred to as photoacid generators) include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimino photoacid generators, and imide photoacids. Generator, benzoin sulfonate photoacid generator, pyrogallol trisulfonate photoacid generator, nitrobenzyl sulfonate photoacid generator, sulfone photoacid generator, glyoxime derivative photoacid generator, and the like. A sulfonium salt, an iodonium salt, a sulfonyldiazomethane, an N-sulfonyloxyimino type photoacid generator or an imide type photoacid generator is preferred. Examples of radiation include electron beams, extreme ultraviolet rays, far ultraviolet rays, near ultraviolet rays (i rays, etc.), visible light (g rays, h rays, etc.), far infrared rays, and the like. The compounds that generate an acid upon irradiation with radiation may be used alone or in admixture of two or more.

  The sulfonium salt is a salt of a sulfonium cation and a sulfonate. Examples of the sulfonium cation include triphenylsulfonium, (4-tert-butoxyphenyl) diphenylsulfonium, bis (4-tert-butoxyphenyl) phenylsulfonium, tris (4-tert-butoxyphenyl) sulfonium, (3-tert- Butoxyphenyl) diphenylsulfonium, bis (3-tert-butoxyphenyl) phenylsulfonium, tris (3-tert-butoxyphenyl) sulfonium, (3,4-ditert-butoxyphenyl) diphenylsulfonium, bis (3,4-di tert-butoxyphenyl) phenylsulfonium, tris (3,4-ditert-butoxyphenyl) sulfonium, diphenyl (4-thiophenoxyphenyl) sulfonium, (4-tert Butoxycarbonylmethyloxyphenyl) diphenylsulfonium, tris (4-tert-butoxycarbonylmethyloxyphenyl) sulfonium, (4-tert-butoxyphenyl) bis (4-dimethylaminophenyl) sulfonium, tris (4-dimethylaminophenyl) sulfonium 2-naphthyldiphenylsulfonium, dimethyl-2-naphthylsulfonium, 4-hydroxyphenyldimethylsulfonium, 4-methoxyphenyldimethylsulfonium, trimethylsulfonium, 2-oxocyclohexylcyclohexylmethylsulfonium, trinaphthylsulfonium, tribenzylsulfonium, etc. . Examples of the sulfonate include trifluoromethane sulfonate, nonafluorobutane sulfonate, heptadecafluorooctane sulfonate, 2,2,2-trifluoroethane sulfonate, pentafluorobenzene sulfonate, 4-trifluoromethylbenzene sulfonate, and 4-fluorobenzene sulfonate. , Toluenesulfonate, benzenesulfonate, 4- (4-toluenesulfonyloxy) benzenesulfonate, naphthalenesulfonate, camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate, butanesulfonate, methanesulfonate, and the like.

  An iodonium salt is a salt of an iodonium cation and a sulfonate. Examples of the iodonium cation include aryl iodonium cations such as diphenyliodonium, bis (4-tert-butylphenyl) iodonium, (4-tert-butoxyphenyl) phenyliodonium, (4-methoxyphenyl) phenyliodonium, and the like. Here, examples of the sulfonate include the groups exemplified above as the sulfonate.

  Examples of the sulfonyldiazomethane include bis (ethylsulfonyl) diazomethane, bis (1-methylpropylsulfonyl) diazomethane, bis (2-methylpropylsulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, and bis (cyclohexylsulfonyl). ) Diazomethane, bis (perfluoroisopropylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (4-methylphenylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, bis (2-naphthylsulfonyl) diazomethane, (4-methylphenyl) sulfonylbenzoyldiazomethane, (tert-butylcarbonyl)-(4-methylphenylsulfonyl) diazomethane, (2-na Bissulfonyldiazomethane, sulfonylcarbonyldiazomethane, such as (tilsulfonyl) benzoyldiazomethane, (4-methylphenylsulfonyl)-(2-naphthoyl) diazomethane, methylsulfonylbenzoyldiazomethane, (tert-butoxycarbonyl)-(4-methylphenylsulfonyl) diazomethane Etc.

  Examples of the N-sulfonyloxyimino photoacid generator include [5- (4-methylphenylsulfonyloxyimino) -5H-thiophen-2-ylidene]-(2-methylphenyl) acetonitrile, (5-propylsulfonyl). Oxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitrile (CGI-1397), (5-camphorsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitrile, α- (9-camphorsulfonyloxyimino) -4-methoxybenzeneacetonitrile, α- (4-methylphenylsulfonyloxyimino) benzeneacetonitrile, α- (4-methylphenylsulfonyloxyimino) -4-methoxybenzeneacetonitrile, etc. Raising It is.

  Examples of the N-sulfonyloxyimide photoacid generator include succinimide, naphthalene dicarboxylic imide, phthalic imide, cyclohexyl dicarboxylic imide, 5-norbornene-2,3-dicarboxylic imide, 7-oxabicyclo [ 2.2.1] Examples include compounds composed of a combination of an imide skeleton such as -5-heptene-2,3-dicarboxylic imide and a sulfonate. Here, examples of the sulfonate include the groups exemplified above as the sulfonate.

Examples of the benzoin sulfonate photoacid generator include benzoin tosylate, benzoin mesylate, and benzoin butane sulfonate.
Examples of the pyrogallol trisulfonate photoacid generator include compounds in which all hydroxy groups such as pyrogallol, fluoroglycine, catechol, resorcinol and hydroquinone are substituted with sulfonate. Here, examples of the sulfonate include the groups exemplified above as the sulfonate.

  Examples of the nitrobenzyl sulfonate photoacid generator include 2,4-dinitrobenzyl sulfonate, 2-nitrobenzyl sulfonate, 2,6-dinitrobenzyl sulfonate, and the like. Here, examples of the sulfonate include the groups exemplified above as the sulfonate. A compound in which the nitro group on benzyl is replaced with trifluoromethyl can also be used.

  Examples of the sulfone photoacid generator include bis (phenylsulfonyl) methane, bis (4-methylphenylsulfonyl) methane, bis (2-naphthylsulfonyl) methane, 2,2-bis (phenylsulfonyl) propane, 2, 2-bis (4-methylphenylsulfonyl) propane, 2,2-bis (2-naphthylsulfonyl) propane, 2-methyl-2- (p-toluenesulfonyl) propiophenone, 2- (cyclohexylcarbonyl) -2- (P-toluenesulfonyl) propane, 2,4-dimethyl-2- (p-toluenesulfonyl) pentan-3-one and the like.

  Examples of glyoxime derivative-type photoacid generators include bis-O- (p-toluenesulfonyl) -α-dimethylglyoxime, bis-O- (p-toluenesulfonyl) -α-diphenylglyoxime, and bis-O. -(P-toluenesulfonyl) -α-dicyclohexylglyoxime, bis-O- (p-toluenesulfonyl) -2,3-pentanedione glyoxime, bis-O- (p-toluenesulfonyl) -2-methyl-3 , 4-pentanedione glyoxime, bis-O- (n-butanesulfonyl) -α-dimethylglyoxime, bis-O- (n-butanesulfonyl) -α-diphenylglyoxime, bis-O- (n-butane Sulfonyl) -α-dicyclohexylglyoxime, bis-O- (n-butanesulfonyl) -2,3-pentanedione Xime, bis-O- (n-butanesulfonyl) -2-methyl-3,4-pentanedione glyoxime, bis-O- (methanesulfonyl) -α-dimethylglyoxime, bis-O- (trifluoromethanesulfonyl) -Α-dimethylglyoxime, bis-O- (1,1,1-trifluoroethanesulfonyl) -α-dimethylglyoxime, bis-O- (tert-butanesulfonyl) -α-dimethylglyoxime, bis-O -(Perfluorooctanesulfonyl) -α-dimethylglyoxime, bis-O- (cyclohexylsulfonyl) -α-dimethylglyoxime, bis-O- (benzenesulfonyl) -α-dimethylglyoxime, bis-O- (p -Fluorobenzenesulfonyl) -α-dimethylglyoxime, bis-O- (p-tert-butyl) Benzenesulfonyl)-.alpha.-dimethylglyoxime, bis -O- (xylene sulfonyl)-.alpha.-dimethylglyoxime, bis -O- (camphorsulfonyl)-.alpha.-dimethylglyoxime, and the like.

The content of the photoacid generator in the positive radiation sensitive resin composition of the present invention is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the polymer (I), 0.3 to More preferred is 10 parts by weight. You may use a photo-acid generator individually or in mixture of 2 or more types.
Furthermore, the positive radiation-sensitive resin composition of the present invention may contain a photosensitizer, for example, a dye such as anthracenes, anthraquinones, coumarins, and pyromethenes.

  Examples of the organic solvent contained in the positive radiation-sensitive resin composition of the present invention include ketones such as acetone, cyclohexanone, cyclopentanone, 2-heptanone, 3-heptanone, 4-heptanone, and 3-methoxybutanol. 3-methyl-3-methoxybutanol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol-tert-butyl ether methyl ether (1-tert-butoxy-2- Methoxyethane), ethylene glycol-tert-butyl ether ethyl ether (1-tert-butoxy-2-ethoxyethane) and the like. Tellurium, cyclic ethers such as dioxane, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl-3-methoxypropionate, ethyl-3-ethoxypropionate And esters such as tert-butyl acetate, tert-butyl propionate and methyl β-methoxyisobutyrate, and aromatic solvents such as xylene and toluene. Among these, propylene glycol monomethyl ether acetate, which is excellent in solubility and safety of the polymer (I), is preferable. These organic solvents may be used alone or in admixture of two or more. The content of the organic solvent in the positive radiation sensitive resin composition of the present invention is preferably 20 to 80% by weight.

  Further, the positive radiation-sensitive resin composition of the present invention includes, for example, benzyl ethyl ether, dihexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, acetonyl acetone, isophorone, caproic acid, caprylic acid, 1- It may contain a high boiling point solvent such as octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, and phenyl cellosolve acetate.

  The positive radiation sensitive resin composition of the present invention may contain a basic compound. The basic compound present in the resist formed by applying the positive radiation sensitive resin composition on the substrate suppresses diffusion of the acid generated by exposure to the unexposed area. Therefore, by adding a basic compound to the composition, the resolution of a resist pattern formed by performing heat treatment after exposure and developing after the heat treatment can be improved. The content of the basic compound in the positive radiation sensitive resin composition of the present invention is preferably 0.01 to 5 parts by weight, and 0.01 to 2 parts by weight with respect to 100 parts by weight of the polymer (I). More preferably, it is part.

  Examples of the basic compound include ammonia, primary, secondary or tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, sulfonyl Nitrogen-containing compounds having a group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amide derivatives, imide derivatives and the like. You may use a basic compound individually or in mixture of 2 or more types.

  Examples of primary aliphatic amines include methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, pentylamine, tert-amylamine, and cyclopentylamine. Hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine, dodecylamine, cetylamine, methylenediamine, ethylenediamine, tetraethylenepentamine and the like.

  Secondary aliphatic amines include, for example, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, disec-butylamine, dipentylamine, dicyclopentylamine, dihexylamine, Examples include dicyclohexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, didodecylamine, dicetylamine and the like.

  Tertiary aliphatic amines include, for example, tris (2-methoxyethyl) amine, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, trisec-butylamine, Tripentylamine, tricyclopentylamine, trihexylamine, tricyclohexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, tridodecylamine, tricetylamine, N, N, N ', N'- Examples include tetramethylmethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, and the like.

Examples of hybrid amines include benzylamine, phenethylamine, and benzyldimethylamine.
Examples of aromatic amines and heterocyclic amines include aniline derivatives [eg, aniline, N-methylaniline, N-ethylaniline, N-propylaniline, N, N-dimethylaniline, 2-methylaniline, 3- Methylaniline, 4-methylaniline, ethylaniline, propylaniline, trimethylaniline, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline, 2,6-dinitroaniline, 3,5- Dinitroaniline, N, N-dimethyltoluidine, diphenyl (p-tolyl) amine, methyldiphenylamine, triphenylamine, phenylenediamine, etc.], naphthylamine, diaminonaphthalene, pyrrole derivatives (eg, pyrrole, 1-methylpyrrole, 2,4 -Dimethyl pillow , 2,5-dimethylpyrrole, etc.), oxazole derivatives (eg oxazole, isoxazole etc.), thiazole derivatives (eg thiazole, isothiazole etc.), imidazole derivatives (eg imidazole, 4-methylimidazole, 4-methyl- 2-phenylimidazole, etc.), pyrazole derivatives, furazane derivatives, pyrroline derivatives (eg, pyrroline, 2-methyl-1-pyrroline, etc.), pyrrolidine derivatives (eg, pyrrolidine, N-methylpyrrolidine, pyrrolidinone, etc.), imidazoline derivatives, imidazo Lysine derivatives, pyridine derivatives [for example, pyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine, 2-hydroxypyridine, 4- (1-butylpentyl) pyridine, dimethylpyridine, trime Rupyridine, triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine, 4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 4-pyrrolidinopyridine, 2- (1- Ethylpropyl) pyridine, aminopyridine, dimethylaminopyridine, etc.], pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives, pyrazoline derivatives, pyrazolidine derivatives, piperidine derivatives, piperazine derivatives, morpholine derivatives, indole derivatives, isoindole derivatives, indazole derivatives, indoline derivatives Quinoline derivatives (eg, quinoline, 3-quinolinecarbonitrile, etc.), isoquinoline derivatives, cinnoline derivatives, quinazoline derivatives, quinoxari Derivatives, phthalazine derivatives, purine derivatives, pteridine derivatives, carbazole derivatives, phenanthridine derivatives, acridine derivatives, phenazine derivatives, 1,10-phenanthroline derivatives, adenine derivatives, adenosine derivatives, guanine derivatives, guanosine derivatives, uracil derivatives, uridine derivatives Etc.

  Examples of the nitrogen-containing compound having a carboxyl group include aminobenzoic acid, indolecarboxylic acid, amino acid or amino acid derivative (for example, nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycylleucine, leucine Methionine, phenylalanine, threonine, lysine, 3-aminopyrazine-2-carboxylic acid, methoxyalanine and the like).

Examples of the nitrogen-containing compound having a sulfonyl group include 3-pyridinesulfonic acid, pyridinium p-toluenesulfonate, and the like.
Examples of nitrogen-containing compounds and alcoholic nitrogen-containing compounds having a hydroxyphenyl group include aminocresol, 2,4-quinolinediol, 3-indolemethanol hydrate, diethanolamine, triethanolamine, N-ethyldiethanolamine, N, N -Diethylethanolamine, triisopropanolamine, 2,2'-iminodiethanol, 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, 4- (2-hydroxyethyl) morpholine, 2- (2-hydroxyethyl) pyridine, 1- (2-hydroxyethyl) piperazine, 1- [2- (2-hydroxyethoxy) ethyl] piperazine, piperidine ethanol, 1- (2-hydroxyethyl) pyrrolidine, 1- (2 -Hydroxy Ethyl) -2-pyrrolidinone, 3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2-propanediol, 8-hydroxyurolidine, 3-quinuclidinol, 3-tropanol, 1-methyl-2-pyrrolidine Examples include ethanol, 1-aziridine ethanol, N- (2-hydroxyethyl) phthalimide, N- (2-hydroxyethyl) isonicotinamide, and the like.

Examples of the amide derivative include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide and the like.
Examples of the imide derivative include phthalimide, succinimide, maleimide and the like.

The positive radiation-sensitive resin composition of the present invention may contain a surfactant in order to improve applicability.
Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene Polyoxyethylene alkylaryl ethers such as ethylene nonylphenyl ether, polyoxyethylene polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan fatty acid esters such as sorbitan monostearate, polyoxyethylene sorbitan mono Laurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxye Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as lensorbitan trioleate and polyoxyethylene sorbitan tristearate, EFTOP EF301, EF303, EF352 (all manufactured by Gemco), MegaFuck F171, F172, F173 (All manufactured by DIC), Florard FC430, FC431, Novec FC-4430 (all manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-381, S-382, SC101, SC102, SC103, SC104, SC105, SC106 , Surfactol E1004, KH-10, KH-20, KH-30, KH-40 (all manufactured by Asahi Glass Co., Ltd.) and other fluorosurfactants, organosiloxane polymers KP341, X-70- 92, X-70-093 (all manufactured by Shin-Etsu Chemical Co., Ltd.), acrylic acid or methacrylic acid Polyflow No. 75, no. 95 (both manufactured by Kyoeisha Chemical Co., Ltd.). These surfactants may be used alone or in admixture of two or more. The content of the surfactant in the positive radiation sensitive resin composition of the present invention is preferably 0.01 to 2 parts by weight, and 0.1 to 1 part by weight with respect to 100 parts by weight of the polymer (I). More preferably, it is part.

The positive radiation sensitive resin composition of the present invention may contain a dissolution inhibitor in order to further improve the resolution.
As a dissolution inhibitor, a hydrogen atom of the phenolic hydroxyl group of a compound having two or more phenolic hydroxyl groups in the molecule is tert-butyl, tert-butoxycarbonyl, butoxycarbonylmethyl, 2-tetrahydropyranyl, 2- A compound substituted with an acid labile group such as tetrahydrofuranyl, ethoxyethyl, ethoxypropyl and the like at an average ratio of 10 to 100 mol% is preferred. The weight average molecular weight of the compound is preferably 100 to 1,000, and more preferably 150 to 800. The content of the dissolution inhibitor in the positive radiation sensitive resin composition of the present invention is preferably 0.01 to 50 parts by weight, and 5 to 40 parts by weight with respect to 100 parts by weight of the polymer (I). More preferably. These dissolution inhibitors may be used alone or in admixture of two or more.

  Examples of the dissolution inhibitor include bis [4- (2′-tetrahydropyranyloxy) phenyl] methane, bis [4- (2′-tetrahydrofuranyloxy) phenyl] methane, and bis (4-tert-butoxyphenyl). Methane, bis (4-tert-butoxycarbonyloxyphenyl) methane, bis (4-tert-butoxycarbonylmethyloxyphenyl) methane, bis [4- (1′-ethoxyethoxy) phenyl] methane, bis [4- (1 '-Ethoxypropyloxy) phenyl] methane, 2,2-bis [4'-(2 "-tetrahydropyranyloxy) phenyl] propane, 2,2-bis [4 '-(2" -tetrahydrofuranyloxy) ) Phenyl] propane, 2,2-bis (4′-tert-butoxyphenyl) propane, 2,2-bis (4′-t) rt-butoxycarbonyloxyphenyl) propane, 2,2-bis (4-tert-butoxycarbonylmethyloxyphenyl) propane, 2,2-bis [4 ′-(1 ″ -ethoxyethoxy) phenyl] propane, 2, 2-bis [4 ′-(1 ″ -ethoxypropyloxy) phenyl] propane, 4,4-bis [4 ′-(2 ″ -tetrahydropyranyloxy) phenyl] tert-butyl valerate, 4,4 -Bis [4 ′-(2 ″ -tetrahydrofuranyloxy) phenyl] tert-butyl 4,4-bis (4′-tert-butoxyphenyl) valerate, 4,4-bis (4 '-Tert-Butoxycarbonyloxyphenyl) tert-butyl valerate, 4,4-bis (4'-tert-butoxycarbonylmethyloxyph) Tert-butyl valerate, 4,4-bis [4 ′-(1 ″ -ethoxyethoxy) phenyl] tert-butyl valerate, 4,4-bis [4 ′-(1 ″ -ethoxypropyloxy) ) Phenyl] tert-butyl valerate, tris [4- (2′-tetrahydropyranyloxy) phenyl] methane, tris [4- (2′-tetrahydrofuranyloxy) phenyl) methane, tris (4-tert-butoxyphenyl) ) Methane, tris (4-tert-butoxycarbonyloxyphenyl) methane, tris (4-tert-butoxycarbonylmethyloxyphenyl) methane, tris [4- (1′-ethoxyethoxy) phenyl] methane, tris [4- ( 1′-ethoxypropyloxy) phenyl] methane, 1,1,2-tris [4 ′-(2 ″ -tetrahydro Ranyloxy) phenyl] ethane, 1,1,2-tris [4 ′-(2 ″ -tetrahydrofuranyloxy) phenyl] ethane, 1,1,2-tris (4′-tert-butoxyphenyl) ethane, 1, 1,2-tris (4′-tert-butoxycarbonyloxyphenyl) ethane, 1,1,2-tris (4′-tert-butoxycarbonylmethyloxyphenyl) ethane, 1,1,2-tris [4′- (1 ″ -ethoxyethoxy) phenyl] ethane, 1,1,2-tris [4 ′-(1 ″ -ethoxypropyloxy) phenyl] ethane and the like.

  The positive-type radiation-sensitive resin composition of the present invention is for the purpose of preventing halation and the like, for example, an ultraviolet absorber such as 2,2 ′, 4,4′-tetrahydroxybenzophenone, 4-dimethylamino-2 ′, 4. '-Dihydroxybenzophenone, 5-amino-3-methyl-1-phenyl-4- (4-hydroxyphenylazo) pyrazole, 4-dimethylamino-4'-hydroxyazobenzene, 4-diethylamino-4'-ethoxyazobenzene, 4 -Diethylaminoazobenzene, curcumin, 1,7-bis (3-methoxy-4-hydroxyphenyl) -1,6-heptadiene-3,5-dione, 5-hydroxy-4- (4-methoxyphenylazo) -3- It may contain methyl-1-phenylpyrazole and the like. These ultraviolet absorbers may be used alone or in admixture of two or more. The content of the ultraviolet absorber in the positive radiation sensitive resin composition of the present invention is preferably 0.01 to 2 parts by weight, and 0.01 to 1 part by weight with respect to 100 parts by weight of the polymer (I). More preferably, it is part.

By incorporating another resin, modifier or plasticizer into the positive radiation sensitive resin composition of the present invention, a resist formed by coating the positive radiation sensitive resin composition on a substrate can be used. Flexibility can be improved.
Examples of other resins include homopolymers or copolymers of monomers having an ethylenically unsaturated bond, polyester resins obtained by condensation reaction of polyacid bases and polybasic acids, phenol or cresol and aldehydes. Examples thereof include a phenol resin obtained by a condensation reaction, a polyurethane resin obtained from a polyol and an isocyanate, an epoxy resin having a cyclic or acyclic alkyl group, and derivatives thereof. These resins may be used alone or in admixture of two or more. The weight average molecular weight of these resins is preferably 1,000 to 1,000,000, and more preferably 3,000 to 600,000.

  Examples of the modifier include polyethylene glycol, polypropylene glycol, polybutadiene polyol, α-hydroxyethyl-ω-hydroxymethyl poly (1-ethoxyethylene), polytetramethylene ether glycol, polyester polyol, polycaprolactone polyol, polycarbonate polyol, Examples include polybutadiene dicarboxylic acid. These oligomers may be used alone or in admixture of two or more. The weight average molecular weight of these resins is preferably 300 to 30,000, and more preferably 500 to 10,000.

  Examples of the plasticizer include phthalic acid plasticizers such as dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate and ditridecyl phthalate, adipic acid plasticizers such as dibutyl adipate and dioctyl adipate, succinic acid, and 2,4-diethylglutaric acid. And polybasic acid esters. These plasticizers may be used alone or in admixture of two or more.

The content of the other resin, the modifier or the plasticizer in the positive radiation sensitive resin composition of the present invention is preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the polymer (I). More preferably, they are 0.5 to 30 parts by weight, respectively.
The positive radiation sensitive resin composition of the present invention may contain a storage stabilizer, an antifoaming agent and the like.

When the positive radiation sensitive resin composition of the present invention is used for forming a resist pattern or the like, the composition may be used as it is, and the composition is made into a film and the composition is made into a paste. You may use things.
The resist pattern forming method of the present invention includes a step of exposing a resist formed by applying the positive radiation sensitive resin composition of the present invention on a substrate, a step of performing a heat treatment after the exposure, and the heat treatment. And a later development step.

The substrate is preferably a substrate made of a material that can be plated, a substrate that is a laminate of a seed film made of a material that can be plated, and a base material. Examples of materials that can be plated include nickel, tin, zinc, gold, silver, and copper. Among these, nickel and copper are preferable.
Examples of the substrate include glass, silicon, oxide film-coated glass [ITO (indium titanium oxide) -coated glass, etc.], metals (aluminum, gold, silver, copper, iron, true nickel, tin, zinc, brass plate, Tin plate, etc.), plastics (polycarbonate resin, acrylic resin, polyethylene terephthalate, acrylonitrile = butadiene = styrene copolymer resin, polyimide, vinyl chloride, polystyrene, etc.), porcelain, earthenware, ceramic and the like.

A substrate that is a laminate of a seed film made of a material that can be plated and a base material can be obtained by, for example, a method of forming a seed film on one surface of a plate-like base material by sputtering or the like. .
As a method of forming a resist by applying a positive radiation-sensitive resin composition on a substrate, for example, the composition is applied on a substrate using a spin coater, a slit coater, etc. and then heated at 60 to 140 ° C. The method of drying (prebaking) etc. is mention | raise | lifted. The thickness of the resist is preferably 1 to 150 μm.

  Next, the resist formed on the substrate is exposed through a mask having a desired pattern. As a light source used for exposure, for example, a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, an EUV (Extreme-ultra Violet) excimer laser, a DUV (Deep-ultra Violet) excimer laser, a KrF excimer laser, an ArF excimer laser, etc. Can be given.

After the exposure, for example, the substrate is subjected to a heat treatment (post-exposure baking) at 60 to 140 ° C., and then developed by a method of developing with an alkali developer to form a resist pattern on the substrate. Here, the substrate is exposed at the portion exposed through the mask, and the resist remains at the portion shielded from light by the mask.
Examples of the method of developing with an alkali developer include a method of applying an alkali developer on a substrate by a curtain flow method, a method of immersing the substrate in an aqueous alkali solution, and the like. After development, the substrate may be washed with water or the like.

  Examples of the alkaline developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, An alkaline aqueous solution obtained by dissolving dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetramethylammonium hydroxide (TMAH), choline, pyrrole, piperidine and the like in water is used. The developer can also be used by adding an appropriate amount of a water-soluble organic solvent, for example, an alcohol such as methanol or ethanol, or a surfactant.

The method for forming a plating pattern of the present invention includes a step of performing a plating process on a substrate having a resist pattern formed by the above method, and a step of removing the resist from the substrate subjected to the plating process.
By performing a plating process on the substrate having a resist pattern, a metal film is formed at a portion where the substrate is exposed. The thickness of the metal film is preferably 2/3 or less of the thickness of the resist pattern.

Examples of the metal of the metal film include copper, nickel, chromium, zinc, tin, gold, silver, and platinum group metals. Among these, copper, nickel, and gold are preferable, and copper and nickel are more preferable.
Before performing the plating treatment, the substrate may be washed with an organic solvent such as trichlorethylene, an alkaline aqueous solution such as an aqueous sodium hydroxide solution or an aqueous sodium carbonate solution, an acid such as sulfuric acid, hydrochloric acid, or hydrofluoric acid.

  Examples of the plating treatment include electroplating, displacement plating, and electroless plating. Electroplating is a method in which metal ions contained in a plating bath are reduced by electricity to form a metal film. Displacement plating is a method in which a metal having a greater ionization tendency than metal ions contained in the plating bath is inserted into the plating bath, and the metal ions contained in the plating bath are reduced due to the difference in ionization tendency to form a metal film. . Electroless plating is a method of forming a metal film by reducing metal ions in a plating bath with a reducing agent. Among these, electroplating is preferable because a metal film having a thickness of 10 μm or more can be formed.

Examples of plating baths used for forming a nickel metal film by electroplating include nickel plating baths (watt baths) mainly composed of nickel sulfate, nickel chloride and boron, nickel sulfamate, nickel chloride and boron. Examples thereof include a sulfamate bath as a main component. In any of the above plating baths, it is preferably performed at a pH of 2.5 to 5.0. In the case of a Watt bath, it is preferably carried out at 40 to 65 ° C, and in the case of a sulfamate bath, it is preferably carried out at 25 to 65 ° C. In the case of a watt bath, it is preferably carried out at a current density of ^{2 to} 4 A / dm ² , and in the case of a sulfamate bath, it is preferably carried out at a current density of ^{2 to} 90 A / dm ² .

Examples of the plating bath used when forming a copper metal film by electroplating include, for example, a copper sulfate plating bath mainly composed of copper sulfate and sulfuric acid, and cyanide mainly composed of cuprous cyanide and sodium cyanide. Examples thereof include a copper halide plating bath, a copper pyrophosphate plating bath mainly composed of copper pyrophosphate and potassium pyrophosphate. The copper sulfate plating bath is preferably performed at 15 to 35 ° C, and the copper cyanide plating bath or the copper pyrophosphate plating bath is preferably performed at 40 to 65 ° C. The copper cyanide plating bath is preferably performed at pH 11 to 13, and the copper pyrophosphate plating bath is preferably performed at pH 8.0 to 9.0. The copper sulfate plating bath is preferably performed at a current density of 1 to 6 A / dm ² , the copper cyanide plating bath is preferably performed at a current density of 1 to 4 A / dm ² , and the copper pyrophosphate plating bath is 1 to 3 A. It is preferable to carry out at a current density of / dm ² .

After the plating process is performed on the substrate, the plating pattern can be obtained by removing the resist from the substrate.
As a method for removing the resist from the substrate, a chemical or physical method can be used. Specifically, a method of etching the resist with reactive ions such as oxygen plasma, an organic solvent (for example, N-methylpyrrolidone, γ -Butyrolactone, propylene glycol methyl ether, propylene glycol methyl ether acetate, cyclohexanone, acetone, etc.) and a method of dissolving or stripping the resist.

The plating pattern forming method of the present invention includes the manufacture of micromachines, the formation of various metal bumps such as gold, silver, copper, nickel, and solder in semiconductor packages, the formation of connection parts and wiring patterns such as metal posts, and the connection on printed circuit boards. This is useful for forming portions and wiring patterns.
Hereinafter, the present invention will be described more specifically with reference examples, examples and comparative examples.

The weight average molecular weight (polystyrene conversion) of the resin was measured by gel permeation chromatography (GPC) under the following conditions.
(GPC conditions)
Column: TSKgel G4000H, TSKgel G2000H, and TSKgel GMH [all manufactured by Tosoh Corporation] were connected in series.

Column retention temperature: 40 ° C
Mobile phase: Tetrahydrofuran (flow rate 1.0 ml / min)
Detector: RI
Standard substance: Polystyrene (Reference Example 1) Production of cresol novolak resin (P-1a) In a 2 L four-necked flask equipped with a stirrer, thermometer, condenser and water separator, 605 g of m-cresol and 259 g of p-cresol Then, 186 g of 37% formalin aqueous solution and 0.8 g of oxalic acid were charged and refluxed for 4 hours. The mixture was stirred at 180 ° C. under normal pressure for 2 hours, and further stirred at 200 ° C. under reduced pressure of 9.3 × 10 ³ Pa for 1 hour to distill off water and unreacted monomers, thereby weight average molecular weight (polystyrene conversion) 4550 Of cresol novolak resin (P-1a) was obtained.

(Reference Example 2) Production of Resin (P-2) 145.2 g of 2-ethylhexanal was added dropwise to a mixture of 72.4 g of methanol and 3 mg of p-toluenesulfonic acid monohydrate and reacted at room temperature for 2 hours. The reaction solution was distilled under reduced pressure of 4.0 × 10 ³ Pa to obtain 112.0 g of 2-ethylhexanal dimethyl acetal.

After reacting 112.0 g of 2-ethylhexanal dimethyl acetal, 7.3 g of p-toluenesulfonic acid monohydrate and 3.5 g of triethylamine at 90 ° C. for 2 hours, the reaction solution was reduced in pressure to 4.0 × 10 ³ Pa. Distillation below gave 30.2 g of 1-methoxy-2-ethylhexene.
Dissolve 50.0 g of resin (P-1a) in 200 ml of methyl isobutyl ketone, add 13.8 g of 1-methoxy-2-ethylhexene dropwise at room temperature while bubbling hydrogen chloride gas, and further react at room temperature for 2 hours. It was. After nitrogen gas was bubbled into the reaction solution for 20 minutes, 11.7 g of triethylamine was added for neutralization, and after washing with water, the solvent was distilled off. The residue was dropped into 2 L of diethyl ether, and the precipitated solid was collected by filtration and dried to obtain 50.2 g of resin (P-2).

Reference Example 3 Production of Resin (P-3) To a mixture of 150.7 g of isobutanol and 3 mg of p-toluenesulfonic acid monohydrate, 145.2 g of 2-ethylhexanal was added dropwise and reacted at room temperature for 2 hours. Then, the reaction liquid was distilled under reduced pressure of 4.0 × 10 ³ Pa to obtain 131.0 g of 2-ethylhexanal diisobutyl acetal.

After reacting 131.0 g of 2-ethylhexanal diisobutyl acetal, 5.8 g of p-toluenesulfonic acid monohydrate and 2.8 g of triethylamine at 110 ° C. for 2 hours, the reaction solution was reduced in pressure to 4.0 × 10 ³ Pa. Distillation below gave 29.5 g of 1-isobutoxy-2-ethylhexene.
Resin (P-1a) (50.0 g) is dissolved in isobutyl methyl ketone (200 ml). While bubbling hydrogen chloride gas, 15.1 g of 1-isobutoxy-2-ethylhexene is added dropwise at room temperature and further reacted at room temperature for 2 hours. It was. After nitrogen gas was bubbled into the reaction solution for 20 minutes, 12.4 g of triethylamine was added for neutralization, and after washing with water, the solvent was distilled off. The residue was dropped into 2 L of diethyl ether, and the precipitated solid was collected by filtration and dried to obtain 49.1 g of Resin (P-3).

Reference Example 4 Production of Resin (P-4) 1-propoxy-2-methylpropene was produced according to the method described in International Publication No. 2006/115265 pamphlet.
A cresol novolak resin (P-1b) having a weight average molecular weight (polystyrene conversion) of 4500 was produced according to the method described in Reference Example 1.

  Dissolve 50.0 g of resin (P-1b) in 200 ml of isobutyl methyl ketone, add 11.4 g of 1-propoxy-2-methylpropene dropwise at room temperature while bubbling hydrogen chloride gas, and further react at room temperature for 2 hours. It was. Nitrogen gas was bubbled into the reaction solution for 20 minutes, neutralized by adding 12.1 g of triethylamine, washed with water, and the solvent was distilled off. The residue was dropped into 2 L of diethyl ether, and the precipitated solid was collected by filtration and dried to obtain 41.0 g of resin (P-4).

(Preparation of positive radiation sensitive resin composition)
As a photoacid generator, α- (4-methylphenylsulfonyloxyimino) -4-methoxybenzeneacetonitrile (PAI-101 manufactured by Midori Chemical Co., Ltd.) was used.
As an organic solvent, propylene glycol monomethyl ether acetate (manufactured by Kyowa Hakko Chemical Co., Ltd.) was used.

Novec FC-4430 as a surfactant (manufactured by Sumitomo 3M; fluoropolymer 85 to 95% by weight, polyether resin 5 to 10% by weight, 1-methyl-2-pyrrolidinone 1 to 2% by weight, toluene less than 1% by weight ) Was used.
Tris (2-methoxyethyl) amine was used as the basic compound.

  Resin (P-2), a photoacid generator, an organic solvent, a surfactant, and a basic compound were mixed in the proportions shown in Table 1, and filtered through a viscous liquid filter paper to prepare composition 1.

Resin (P-3), a photoacid generator, an organic solvent, a surfactant, and a basic compound were mixed in the proportions shown in Table 1, and filtered through a viscous liquid filter paper to prepare composition 2.
(Comparative Example 1) Resin (P-4), photoacid generator, organic solvent surfactant and basic compound are mixed in the proportions shown in Table 1, and filtered through a viscous liquid filter paper to give composition 3. Prepared.
(Measurement of sensitivity)
The film thickness of the resist was measured with a surface roughness measuring machine (manufactured by Kosaka Laboratory).

Each of Compositions 1 to 3 was applied to a 2-inch silicon wafer having a nickel seed film with a spin coater and prebaked on a hot plate (110 ° C.) for 5 minutes to prepare a sample. Samples with resist thicknesses of 50 μm and 100 μm were prepared.
A mask aligner MA-4 manufactured by SUSS MICROTECH was used as an exposure apparatus, and each sample was irradiated with i-line (365 nm light) while changing the exposure amount. After exposure, post-exposure baking was performed on a hot plate (95 ° C.) for 5 minutes, followed by development with a 2.38% TMAH aqueous solution (25 ° C., 10 minutes), washing with pure water, and drying. The exposure amount when the film thickness of the exposed part after development became 0 was defined as sensitivity.

The sensitivities of the compositions 1 to 3 are shown in Table 2 (when the resist film thickness is 50 μm) and Table 3 (when the resist film thickness is 100 μm).
(Plating pattern formation)

  Samples were prepared using Compositions 1 and 2, and the above sensitivity measurement was performed except that exposure was performed with the same exposure dose as that of the sample used through a mask having an L / S (line and space) of 20 μm. In this way, the sample is exposed, post-exposure-baked, developed, washed and dried in order, so that the resist line (resist pattern protrusion) and the space (resist pattern recess) are on the substrate. A formed resist pattern was obtained.

A sulfamate bath is used as a plating bath, the substrate is immersed in the plating bath at 40 ° C., electroplating is performed at a current density of 5 A / dm ² for 5 hours, and a film thickness of 30 μm is formed on the substrate in the space portion of the resist pattern. A nickel film was formed. The resist line was dissolved or peeled by dipping in acetone at room temperature to obtain a plating pattern on the substrate.
(Comparative Example 2) Sample preparation, exposure, post-exposure baking, development, washing, drying, plating treatment and resist line in the same manner as in Example 3 except that the composition 3 was used instead of the composition 1 or 2. Removal was done sequentially.

(Evaluation of resist pattern)
The front and cross sections of the resist patterns obtained in Example 3 and Comparative Example 2 were observed using an optical microscope and SEM (scanning electron microscope). In Tables 1 and 2, “◯” indicates that the cross-sectional shape of the resist line is rectangular, and that no residual film was observed on the substrate in the space portion, and “×” indicates the case other than that (for example, resist The case where the line is separated from the substrate, the case where a residual film is seen on the substrate in the space portion, the case where the shape of the resist line is broken due to swelling or film reduction, and the like.

Evaluations of the resist patterns of Compositions 1 to 3 are shown in Table 2 (when the resist film thickness is 50 μm) and Table 3 (when the resist film thickness is 100 μm).
(Crack generation during plating)
The resist pattern was observed with an optical microscope before and after the plating treatment in Example 3 and Comparative Example 2. In Tables 1 and 2, “◯” represents that no crack was generated in the resist line after the plating treatment, and “X” represents that a crack was generated in the resist line after the plating treatment.

  Evaluation of the occurrence of cracks in compositions 1 to 3 is shown in Table 2 (when the resist film thickness is 50 μm) and Table 3 (when the resist film thickness is 100 μm).

  According to the present invention, a resist formed by coating on a substrate is exposed, a heat treatment is performed after the exposure, and a good resist pattern can be formed when developing after the heat treatment, and the resist pattern is formed. Provided is a positive radiation-sensitive resin composition that can suppress the occurrence of cracks in the resist pattern when a plating process is performed on the substrate.

Claims (5)

Formula (I)

(In the formula, R ¹ represents alkyl having 1 to 8 carbon atoms, R ² represents a hydrogen atom, substituted or unsubstituted alkyl, substituted or unsubstituted alicyclic saturated hydrocarbon group, substituted or unsubstituted aryl, or Represents substituted or unsubstituted aralkyl, R ³ represents substituted or unsubstituted alkyl, substituted or unsubstituted alicyclic saturated hydrocarbon group, substituted or unsubstituted aryl, or substituted or unsubstituted aralkyl, and n represents A compound that represents an integer of 0 to ³ and each R ³ may be the same or different when n is 2 or 3, and a compound that generates an acid upon irradiation with radiation And a positive-type radiation-sensitive resin composition containing an organic solvent. The positive-type radiation-sensitive resin composition according to claim 1, wherein the polymer having the structural unit represented by formula (I) has a weight average molecular weight of 1000 to 100,000. A step of exposing a resist formed by applying the positive radiation-sensitive resin composition according to claim 1 on a substrate, a step of performing a heat treatment after the exposure, and a step of developing after the heat treatment A resist pattern forming method including: The method for forming a resist pattern according to claim 3, wherein the film thickness of the resist formed by applying the positive radiation sensitive resin composition on the substrate is 1 to 150 μm. A method for forming a plating pattern, comprising: a step of plating a substrate having a resist pattern formed by the method according to claim 3; and a step of removing the resist from the substrate subjected to the plating treatment.