JP2008222937A - Polymer and photosensitive resin composition using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition capable of being coated to be a high thickness membrane and alkali developed, having high resolution and small residual stress after curing and preparing cured products excellent in various characteristics such as solvent resistance, impact resistance, close adhesiveness and the like. <P>SOLUTION: A polymer constituting the resin composition comprises a repeating unit having a structure expressed by general formula (1) (wherein R<SP>1</SP>expresses a 4-valent alicyclic hydrocarbon group or a 4-valent alkyl alicyclic hydrocarbon group having a 1-4C alkyl group; A expresses a predetermined 2-valent group) and a repeating unit having a structure expressed by general formula (2) (wherein R<SP>1</SP>expresses the same meaning as that in the general formula (1); B expresses a 2-valent group having a hydroxyl group). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition used for an interlayer insulating film (passivation film), a surface protective film (overcoat film), an insulating film for a high-density mounting substrate, and the like of a semiconductor element, and such a photosensitive resin composition. It relates to the polymer used in the above.

  Conventionally, polyimide-based resins having excellent heat resistance, mechanical properties, and the like have been widely used for surface protective films, interlayer insulating films, and the like used in semiconductor devices of electronic devices. In addition, various photosensitive polyimide resins have been proposed in which photosensitivity is imparted to improve film formation accuracy through high integration of semiconductor elements. For example, Patent Document 1 discloses a photosensitive composition using an aromatic polyimide precursor having an acrylic side chain. However, the system using the photosensitive composition disclosed in Patent Document 1 cannot cope with a high film thickness due to the problem of light transmittance, and has a large residual stress after curing. There were also environmental and safety issues.

  In order to solve these problems, many proposals have been conventionally made. For example, Patent Document 2 proposes a positive photosensitive polyimide composition capable of alkali development. However, there are problems in residual stress and solvent resistance after curing. Patent Document 3 proposes a negative photosensitive polyimide composition capable of alkali development. However, there was a problem in applicability, the resolution was low, and it was not practical. Many other patents have been filed, but it is difficult to sufficiently satisfy the required characteristics due to high integration and thinning of semiconductor elements. In particular, the warpage of a semiconductor element due to a large residual stress after curing cannot be ignored, and there is a problem that it is difficult to use industrially.

JP 63-125510 A Japanese Patent Laid-Open No. 3-209478 JP 2000-26603 A

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is that it can be applied with a high film thickness, can be developed with an alkali, and has high resolution. Another object of the present invention is to provide a photosensitive resin composition capable of preparing a cured product having a small residual stress after curing and excellent properties such as solvent resistance, thermal shock resistance and adhesion.

  As a result of intensive studies to achieve the above-described problems, the present inventors have found that the above-described problems can be achieved by adopting the following configuration, and have completed the present invention.

  That is, according to the present invention, the following polymer, photosensitive composition, and cured film are provided.

  [1] A polymer having a repeating unit having a structure represented by the following general formula (1) and a repeating unit having a structure represented by the following general formula (2).

In the general formula (1), R ¹ represents a tetravalent alicyclic hydrocarbon group or an alkyl alicyclic hydrocarbon group substituted with an alkyl group having 1 to 4 carbon atoms (provided that R ¹ is In the case of the alkyl alicyclic hydrocarbon group, a tetravalent group substituted by two or more simultaneously from the same alkyl group is excluded). A represents a divalent group represented by the following general formula (3).

In the general formula (2), R ¹ has the same meaning as R ¹ in the general formula (1), and B represents a divalent group having a hydroxyl group.

In the general formula (3), each R ² independently represents an alkyl group having 1 to 3 carbon atoms or an aryl group that may have a substituent, and m represents an integer of 1 to 10. , N represents an integer of 1-30.

  [2] The polymer according to [1], wherein n = 1 in the general formula (3).

  [3] A photosensitive resin composition containing (A) the polymer according to [1] or [2], (B) a photosensitive acid generator, and (C) a crosslinking agent.

  [4] The photosensitive resin composition according to [3], wherein (C) the crosslinking agent is a compound having an alkoxyalkylated amino group.

  [5] A cured film formed using the photosensitive resin composition according to [3] or [4].

  The polymer of the present invention can be applied at a high film thickness, can be developed with an alkali, has high resolution, has low residual stress after curing, and has various properties such as solvent resistance, thermal shock resistance, and adhesion. The effect that the photosensitive resin composition which can prepare the hardened | cured material excellent in the characteristic can be provided is produced.

  The photosensitive resin composition of the present invention can be applied at a high film thickness, can be developed with an alkali, has high resolution, has low residual stress after curing, and has solvent resistance, thermal shock resistance, and adhesion. The effect that the hardened | cured material excellent in various characteristics, such as these, can be obtained is produced. Moreover, the photosensitive resin composition of the present invention is suitable for surface protective film applications, interlayer insulating film applications, and insulating film applications for high-density mounting substrates.

  The cured film of the present invention is excellent in various properties such as solvent resistance, thermal shock resistance, and adhesion, and is suitable as a surface protective film, an interlayer insulating film, an insulating film for a high-density mounting substrate, and the like.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

1. (A) Polymer:
R ¹ in the general formulas (1) and (2) is a tetravalent alicyclic hydrocarbon group or a tetravalent alkyl alicyclic hydrocarbon group having an alkyl group having 1 to 4 carbon atoms. However, when R ¹ is a “tetravalent alkyl alicyclic hydrocarbon group”, the “tetravalent alkyl alicyclic hydrocarbon group” is simultaneously substituted with two or more from the same alkyl group. Tetravalent groups are not included. Specifically, these tetravalent alicyclic hydrocarbon groups and tetravalent alkyl alicyclic hydrocarbon groups are those of the parent skeleton (carbon skeleton) such as alicyclic hydrocarbon and alkyl alicyclic hydrocarbon. Four hydrogens are substituted groups.

  Specific examples of alicyclic hydrocarbons include monocyclic hydrocarbons, bicyclic hydrocarbons, and tricyclic or higher hydrocarbons.

Specific examples of the monocyclic hydrocarbon include cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclohexane, cyclohexene, cyclooctane and the like. Bicyclic hydrocarbons include bicyclo [2.2.1] heptane, bicyclo [3.1.1] heptane, bicyclo [3.1.1] hept-2-ene, bicyclo [2.2.2]. Examples include octane and bicyclo [2.2.2] oct-7-ene. Examples of the tricyclic or higher hydrocarbon include tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [5.2.1.0 ^2,6 ] dec-4-ene, adamantane, tetracyclo [ 6.2.1.1 ^3,6 . 0 ^2,7 ] dodecane and the like.

  Specific examples of the alkyl alicyclic hydrocarbon include those obtained by replacing the alicyclic hydrocarbon with an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group.

Among the specific examples of the above monocyclic hydrocarbon and alkyl alicyclic hydrocarbon, cyclobutane, cyclopentane, cyclohexane, bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, bicyclo [ 2.2.2] Oct-7-ene, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecane, methylcyclopentane and the like are preferable.

Particularly preferred as R ¹ is

である。

It is.

A in the general formula (1) is a divalent group represented by the general formula (3). Moreover, R < ² > in the said General formula (3) is respectively independently the C1-C3 alkyl group or the aryl group which may have a substituent. Specific examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, and a propyl group. Of these, a methyl group and an ethyl group are preferable, and a methyl group is more preferable. Specific examples of the “aryl group” of the “aryl group optionally having substituent (s)” include a phenyl group and a naphthyl group. Of these, a phenyl group is preferred. As specific examples of the aryl group having a substituent, hydrogen of the above “aryl group” is a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, 1- Examples include groups substituted with a methylpropyl group, a t-butyl group, a hydroxyl group, a carboxyl group, and the like. Of these, a group substituted with a methyl group or a hydroxyl group is preferred.

  M in the said General formula (3) is an integer of 1-10, Preferably it is an integer of 1-7, More preferably, it is an integer of 1-5. Moreover, n in the said General formula (3) is an integer of 1-30, Preferably it is an integer of 1-20, More preferably, it is an integer of 1-15. In general formula (3), n = 1 is most preferable.

  B in the general formula (2) is a divalent group having a hydroxyl group. As a specific example of B,

等の水酸基を１つ有する２価の基、

A divalent group having one hydroxyl group, such as

等の水酸基を２つ有する２価の基、

A divalent group having two hydroxyl groups such as

等の水酸基を３つ有する２価の基、及び

A divalent group having three hydroxyl groups such as

等の水酸基を４つ有する２価の基等を挙げることができる。これらのうち、水酸基を２つ有する２価の基が好ましく、

And a divalent group having four hydroxyl groups. Of these, a divalent group having two hydroxyl groups is preferred,

が更に好ましい。

Is more preferable.

  The polymer (A) of the present invention is usually a monomer represented by the following general formula (4) (hereinafter also referred to as “monomer 4”), a monomer represented by the following general formula (5) (hereinafter referred to as “monomer”). 5 ”), and a monomer represented by the following general formula (6) (hereinafter also referred to as“ monomer 6 ”) in a polymerization solvent to synthesize a polyamic acid, and further carry out an imidization reaction. Obtainable. In general, the following two methods are known for the synthesis procedure of polyamic acid. That is, (1) a method in which the monomer 5 and the monomer 6 are dissolved in the polymerization solvent and the monomer 4 is reacted; and (2) after the monomer 4 is dissolved in the polymerization solvent, the monomer 5 is reacted, and the monomer 6 is further reacted. It is a method to make it. Any method may be used, but it is preferable to react by the method (1) when the reactivity of the monomer 5 is high, and by the method (2) when the reactivity of the monomer 5 is low. In addition, the (A) polymer should just contain the repeating unit which has a structure shown by the said General formula (1) and (2). Therefore, the polymer (A) may be either a block copolymer or a random copolymer.

  As a commercial item of the monomer 5, for example, trade names “TSL9386”, “TSL9346”, “TSL9306” manufactured by Toshiba Silicone Co., Ltd., trade names “BY16-853C”, “BY16-887EG” manufactured by Toray Dow Corning, Product name “X-22-161AS” manufactured by Shin-Etsu Chemical Co., Ltd., product name “F2-053-01” manufactured by Nihon Unicar Company Limited, product names “Silaplane FM3325”, “same FM 3321” manufactured by Chisso Corporation FM3311 "and the like.

  As a polymerization solvent, aprotic solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, γ-butyrolactone, and dimethyl sulfoxide; used. If necessary, these solvents may include methanol, ethanol, propanol, butanol, 2-methoxyethanol, 2-ethoxyethanol, 2- (2-methoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethanol and the like. Alcohol solvents; ether solvents such as diglyme and triglyme; aromatic hydrocarbon solvents such as toluene and xylene may be added. The reaction is usually carried out at 20 to 130 ° C. for 1 to 48 hours.

  As the imidization reaction, a heating imidization reaction and a chemical imidation reaction are generally known. However, it is preferable to synthesize the polymer (A) by a heating imidization reaction. The heating imidization reaction is usually performed by heating the polyamic acid synthesis solution at 120 to 210 ° C. for 1 to 16 hours. If necessary, the reaction may be performed while removing water in the system using an azeotropic solvent such as toluene or xylene.

  (A) The polystyrene-converted weight average molecular weight (hereinafter also referred to as “Mw”) of the polymer measured by gel permeation chromatography (GPC) is usually 2,000 to 500,000, preferably 3,000. ~ 250,000. If Mw is less than 2,000, sufficient mechanical properties as an insulating film tend not to be obtained. On the other hand, when Mw exceeds 500,000, the solubility in a solvent or a developer tends to be poor.

  (A) The molar ratio of the monomer 4 contained in all monomers constituting the polymer is usually 40 to 60 mol%, preferably 45 to 55 mol%. When the molar ratio of the monomer 4 to the total monomer is less than 40 mol% or more than 60 mol%, the molecular weight of the polymer (A) tends to decrease.

  The molar ratio of the monomer 5 to the sum of the monomer 5 and the monomer 6 is usually 1 to 80 mol%, preferably 5 to 70 mol%. When the molar ratio of the monomer 5 is within the above range, it is preferable in terms of improving transparency, reducing warpage, and improving alkali developability.

2. Photosensitive resin composition and cured film using the same:
((B) photosensitive acid generator)
The photosensitive acid generator (B) contained in the photosensitive resin composition of the present invention is a compound that generates an acid upon irradiation with radiation (hereinafter also referred to as “exposure”). Examples of such a compound include a chemical amplification type photosensitive acid generator and a naphthoquinone diazide (NQD) type photosensitive acid generator.

  Specific examples of the chemically amplified photosensitive acid generator include iodonium salt compounds, sulfonium salt compounds, sulfone compounds, sulfonic acid ester compounds, halogen-containing compounds, sulfonimide compounds, and diazomethane compounds. Specific examples of naphthoquinone diazide (NQD) -based photosensitive acid generators include diazoketone compounds.

  Specific examples of the iodonium salt compound include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluorobutanesulfonate, diphenyliodoniumpyrenesulfonate, diphenyliodonium dodecylbenzenesulfonate, diphenyliodonium hexafluoroantimonate, bis (4-t-butylphenyl) iodonium. Trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluorobutanesulfonate, bis (4-t-butylphenyl) iodonium camphorsulfonate, bis (4-t-butylphenyl) iodonium p-toluenesulfonate, etc. Can do.

  Specific examples of the sulfonium salt compound include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium camphorsulfonate, triphenylsulfonium naphthalenesulfonate, 4-hydroxyphenyl benzyl methylsulfonium p-toluenesulfonate, 4- (phenylthio) phenyl diphenylsulfonium hexafluorophosphate, 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4,7-di-n-hydroxy-1-naphthyltetrahydrothio Phenium trifluoromethanesulfonate, 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium Sa fluorophosphate, mention may be made of 4-n-butoxy-1-naphthyl tetrahydrothiophenium trifluoromethanesulfonate, and the like.

  Specific examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, and α-diazo compounds thereof. More specifically, phenacylphenylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, 4-trisphenacylsulfone and the like can be mentioned.

  Specific examples of the sulfonate compound include alkyl sulfonate, haloalkyl sulfonate, aryl sulfonate, imino sulfonate, and the like. More specifically, benzoin tosylate, pyrogallol tris-trifluoromethanesulfonate, pyrogallolmethanesulfonic acid triester, nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, α-methylolbenzointosylate, α-methylolbenzoinoctane Examples include sulfonate, α-methylol benzoin trifluoromethane sulfonate, α-methylol benzoindodecyl sulfonate, and the like.

  Specific examples of the halogen-containing compound include haloalkyl group-containing hydrocarbon compounds and haloalkyl group-containing heterocyclic compounds. Specific examples of more preferable halogen-containing compounds include 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane, phenyl-bis (trichloromethyl) -S-triazine, 4-methoxyphenyl-bis (trichloro S-triazines such as methyl) -S-triazine, styryl-bis (trichloromethyl) -S-triazine, 4-methoxystyryl-bis (trichloromethyl) -S-triazine, naphthyl-bis (trichloromethyl) -S-triazine Derivatives can be mentioned.

  Specific examples of the diazo ketone compound include a 1,3-diketo-2-diazo compound, a diazobenzoquinone compound, a diazonaphthoquinone compound, and the like. Specific examples of the more preferred diazoketone compound include 1,2-naphthoquinonediazide-4-sulfonic acid ester compounds of phenols.

  Specific examples of the diazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, and bis (phenylsulfonyl) diazomethane.

  Of these photosensitive acid generators, sulfonium salt compounds, sulfone compounds, halogen-containing compounds, diazoketone compounds, sulfonimide compounds and diazomethane compounds are preferred, and sulfonium salt compounds and halogen-containing compounds are more preferred. Particularly preferred are 4- (phenylthio) phenyl diphenylsulfonium hexafluorophosphate, 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4,7-di-n-hydroxy- 1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4 -Methoxyphenyl-bis (trichloromethyl) -S-triazine, styryl-bis (trichloromethyl) -S-triazine, 4-methoxystyryl-bis (trichloromethyl) -S-triazine.

  These (B) photosensitive acid generators can be used singly or in combination of two or more. The content of the (B) photosensitive acid generator is usually 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass, more preferably 100 parts by mass of the (A) polymer. 0.5 to 3 parts by mass. (B) When the content of the photosensitive acid generator is less than 0.1 parts by mass with respect to 100 parts by mass of the polymer (A), a chemical change due to the catalytic action of the acid generated by exposure is sufficiently caused. May be difficult. On the other hand, when it is more than 20 parts by mass, there is a possibility that application unevenness may occur when applying the photosensitive resin composition, or insulation after curing may be deteriorated.

((C) Crosslinking agent)
The (C) crosslinking agent contained in the photosensitive resin composition of the present invention is a compound that forms a bond with a compounded composition such as a resin or other crosslinking agent molecules by the action of heat or acid. In the photosensitive resin composition of this invention, this (C) crosslinking agent can be contained individually by 1 type or in combination of 2 or more types. Specific examples of the (C) crosslinking agent include polyfunctional (meth) acrylate compounds, epoxy compounds, hydroxymethyl group-substituted phenol compounds, and compounds having an alkoxyalkylated amino group.

  Specific examples of the polyfunctional (meth) acrylate compound include trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and dipentaerythritol. Penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, ethylene glycol di (meth) acrylate, 1,3- Butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) Examples include acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and bis (2-hydroxyethyl) isocyanurate di (meth) acrylate. it can.

  Specific examples of the epoxy compound include novolac type epoxy resins, bisphenol type epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins.

  Specific examples of the hydroxymethyl group-substituted phenol compound include 2-hydroxymethyl-4,6-dimethylphenol, 1,3,5-trihydroxymethylbenzene, 3,5-dihydroxymethyl-4-methoxytoluene [2,6. -Bis (hydroxymethyl) -p-cresol] and the like.

  Specific examples of the compound having an alkoxyalkylated amino group include (poly) methylol melamine, (poly) methylol glycoluril, (poly) methylol benzoguanamine, (poly) methylol urea, and the like. Examples of the nitrogen-containing compound having an active methylol group include compounds in which at least one hydrogen atom of the hydroxyl group of the active methylol group is substituted with an alkyl group such as a methyl group or a butyl group. Of these compounds, compounds having an alkoxyalkylated amino group are preferred as the (C) crosslinking agent.

  The above-mentioned “compound having an alkoxyalkylated amino group” includes a mixture in which a plurality of substituted compounds are mixed and an oligomer component partially self-condensed. Any of these can be used as a “compound having an alkoxyalkylated amino group”. Specific examples of the compound having an alkoxyalkylated amino group include hexamethoxymethylmelamine (trade name “Cymel 300”, manufactured by Mitsui Cyanamid Co., Ltd.), tetrabutoxymethyl glycoluril (trade name “Cymel 1170”, Mitsui). Cyanamid Co., Ltd.), tetramethoxymethylglycoluril (trade name “Cymel 1174”, Mitsui Cyanamid Co., Ltd.) and other products of the Cymel series, My Coat series, UFR series, and others. Of these compounds, hexamethoxymethylmelamine is particularly preferred.

  (C) The content of the crosslinking agent is usually required to be an amount that allows a film formed from the photosensitive resin composition to be sufficiently cured. (C) Content of a crosslinking agent is 5-50 mass parts normally with respect to 100 mass parts of (A) polymers, Preferably it is 10-40 mass parts, More preferably, it is 10-20 mass parts. If the content of the crosslinking agent (C) is less than 5 parts by mass with respect to 100 parts by mass of the polymer (A), the solvent resistance and plating solution resistance of the formed insulating layer may be insufficient. is there. On the other hand, if it exceeds 50 parts by mass, the thin film formed by this photosensitive resin composition may not have sufficient developability.

(solvent)
A solvent can be added to the photosensitive resin composition of the present invention in order to improve the handleability and adjust the viscosity and storage stability. The type of the solvent added for such use is not particularly limited, and examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, γ-butyrolactone, and dimethyl. An aprotic solvent such as sulfoxide or a phenolic protic solvent such as metacresol is used.

It is preferable to use at least one solvent (specific solvent) selected from the following group and having a boiling point of 100 ° C. or higher at normal pressure. Further, it is more preferable that such a specific solvent is contained in an amount of 10% by mass or more based on the total solvent, because such a solvent acts as a photosensitive composition. Further, the ratio of the specific solvent contained in all the solvents is more preferably 30% by mass or more, and particularly preferably 50% by mass or more. In addition, when the ratio of the specific solvent contained in all the solvents is less than 10% by mass, there is a tendency that a coating property is caused or resolution is lowered.
Group: Propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, propylene glycol monoalkyl ether acetates, aliphatic alcohols, lactic acid esters, aliphatic carboxylic acid esters, alkoxy aliphatic carboxylic acid esters, ketones.

  Specific examples of propylene glycol monoalkyl ethers include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether and the like. Specific examples of propylene glycol dialkyl ethers include propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether and the like.

  Specific examples of the propylene glycol monoalkyl ether acetates include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate and the like. Specific examples of the aliphatic alcohols include 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 4-methyl-2-pentanol, 1-hexanol and the like.

  Specific examples of lactic acid esters include methyl lactate, ethyl lactate, n-propyl lactate, isopropyl lactate and the like. Specific examples of aliphatic carboxylic acid esters include n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, isopropyl propionate, n-butyl propionate, and propionic acid. An isobutyl etc. can be mentioned.

  Specific examples of the alkoxy aliphatic carboxylic acid esters include methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate and the like. Specific examples of ketones include 2-heptanone, 3-heptanone, 4-heptanone, cyclopentanone, cyclohexanone, and the like. Of these, ethyl lactate, methyl ethyl ketone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and butyl acetate are more preferred, and ethyl lactate and propylene glycol monomethyl ether are particularly preferred. These specific solvents can be used singly or in combination of two or more. A solvent is normally used so that the total amount of components other than a solvent may be 1-60 mass%.

(Other additives)
In the photosensitive resin composition of the present invention, various additives can be blended as necessary within a range not impairing the effects of the present invention. Examples of additives that can be blended include basic compounds, adhesion assistants, and surfactants.

  Specific examples of basic compounds include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octyl. Trialkylamines such as amine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine, n-dodecyldimethylamine; nitrogen-containing heterocyclic compounds such as pyridine, pyridazine, imidazole, etc. it can. The basic compound is usually blended in an amount of 5 parts by mass or less, preferably 3 parts by mass or less based on 100 parts by mass of the polymer (A). When the compounding amount of the basic compound is more than 5 parts by mass with respect to 100 parts by mass of the polymer (A), the photosensitive acid generator (B) tends to not function sufficiently.

  The adhesion assistant is an additive blended to improve adhesion with the substrate. Specific examples of the adhesion assistant include functional silane coupling agents having reactive substituents such as a carbonyl group, a methacryloyl group, an isocyanate group, and an epoxy group. Specific examples of such functional silane coupling agents include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxylane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ -Glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like can be mentioned. The blending amount of the adhesion assistant is preferably 10 parts by mass or less with respect to 100 parts by mass of the polymer (A).

A surfactant is an additive that is blended to improve coating properties, antifoaming properties, leveling properties, and the like. Specific examples of the surfactant include a fluorine-based surfactant. More specific examples of the fluorosurfactant are “BM-1000”, “BM-1100” (manufactured by BM Chemie), “Megafac F142D”, “Same F172” as trade names below. "F173", "F183" (manufactured by Dainippon Ink & Chemicals, Inc.), "Florard FC-135", "FC-170C", "FC-430", "FC-431" ( As described above, manufactured by Sumitomo 3M), "Surflon S-112", "S-113", "S-131", "S-141", "S-145" (above, manufactured by Asahi Glass) “SH-28PA”, “same-190”, “same-193”, “SZ-6032”, “SF-8428” (manufactured by Toray Dow Corning Silicone) can be used.
It is preferable that the compounding quantity of surfactant shall be 5 mass parts or less with respect to 100 mass parts of (A) polymers.

  In particular, the photosensitive resin composition of the present invention can be suitably used as a material for forming a cured film such as a surface protective film or an interlayer insulating film of a semiconductor element. Hereinafter, a method for forming a cured film will be described with an example.

  The photosensitive resin composition of the present invention is applied to a support such as a resin-coated copper foil, a copper-clad laminate, a silicon wafer with a metal sputtered film, or an alumina substrate, and dried to volatilize the solvent. A film is formed. Then, it exposes through a desired mask pattern and performs heat processing (henceforth this heat processing is also called "PEB"), and promotes reaction with a phenol ring and (C) crosslinking agent. Subsequently, it develops with an alkaline developing solution, A desired pattern can be formed by melt | dissolving and removing an unexposed part. Furthermore, a cured film can be formed by performing a heat treatment for expressing the insulating film characteristics.

  Examples of the method for applying the photosensitive resin composition to the support include coating methods such as a dipping method, a spray method, a bar coating method, a roll coating method, and a spin coating method. Moreover, the thickness of the coating film to be formed can be appropriately controlled by adjusting the coating means and the solid content concentration and viscosity of the photosensitive resin composition.

  After coating the photosensitive resin composition, a pre-bake treatment is usually performed to volatilize the solvent. The conditions for the prebaking treatment vary depending on the formulation of the photosensitive resin composition, the thickness of the coating film, and the like, but are usually 70 to 150 ° C., preferably 80 to 140 ° C., and about 1 to 60 minutes.

Examples of the radiation used for the exposure include ultraviolet rays such as a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a g-line stepper, and an i-line stepper, an electron beam, and a laser beam. The exposure amount is appropriately selected depending on the light source to be used, the thickness of the coating film, and the like. For example, in the case of irradiating ultraviolet rays using a high-pressure mercury lamp, when the coating thickness is 10 to 50 μm, 100 to 5,000 mJ. / Cm ² or so.

  After the exposure, PEB treatment is performed in order to accelerate the curing reaction between the phenol ring and the (C) crosslinking agent by the generated acid. The PEB conditions vary depending on the formulation of the photosensitive resin composition, the thickness of the coating film, and the like, but are usually 70 to 150 ° C., preferably 80 to 140 ° C., and about 1 to 60 minutes.

  Thereafter, development is performed with an alkaline developer, and a desired pattern is formed by dissolving and removing unexposed portions. Examples of the developing method include shower developing method, spray developing method, immersion developing method, paddle developing method and the like. The development conditions are usually about 20 to 40 ° C. and about 1 to 10 minutes.

  Specific examples of the alkaline developer include an alkaline compound obtained by dissolving an alkaline compound such as sodium hydroxide, potassium hydroxide, ammonia water, tetramethylammonium hydroxide, choline, etc. in water so that the concentration is about 1 to 10% by mass. An aqueous solution can be mentioned. For example, a suitable amount of a water-soluble organic solvent such as methanol or ethanol, a surfactant, or the like can be added to the alkaline aqueous solution. After developing with an alkaline developer, it is washed with water and dried.

  In order to sufficiently develop the characteristics as an insulating film, a cured film formed by performing heat treatment after development can be sufficiently cured. The curing conditions are not particularly limited, but may be heated at a temperature of 100 to 400 ° C. for about 30 minutes to 10 hours depending on the use of the cured film.

  It is also preferable to heat in multiple stages in order to sufficiently advance the curing and to prevent deformation of the obtained pattern shape. For example, when heating is performed in two stages, in the first stage, heating is performed at a temperature of 50 to 200 ° C. for about 5 minutes to 2 hours. Furthermore, in the second stage, heating is performed at a temperature of 100 to 400 ° C. for about 10 minutes to 10 hours.

  Under such curing conditions, a hot plate, an oven, an infrared furnace, a microwave oven, or the like can be used as a heating facility.

  Next, a semiconductor element using the photosensitive resin composition of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing an example of a semiconductor element having an insulating resin layer formed using the photosensitive resin composition of the present invention. As shown in FIG. 1, a patterned insulating film 3 is formed on a substrate 1 on which a patterned metal pad 2 is formed using the photosensitive resin composition of the present embodiment. Next, if the metal wiring 4 is formed so as to be connected to the metal pad 2, a semiconductor element can be obtained.

  Further, as shown in FIG. 2, a patterned insulating film 5 may be formed on the metal wiring 4 using the photosensitive resin composition of the present embodiment. As described above, a semiconductor element having an insulating resin layer (cured film) formed using the photosensitive resin composition of the present invention can be produced.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

  [Weight average molecular weight (Mw)]: Using a GPC column (trade name “TSKgelα-M”: 1, product name “TSKgelα-2500”: 1) manufactured by Tosoh Corporation, flow rate: 1.0 ml / min, Elution solvent: N, N-dimethylformamide, column temperature: Measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under analysis conditions of 35 ° C.

  [Mixability]: When an evaluation sample is prepared using the resins obtained in the synthesis examples and comparative synthesis examples, “good” indicates that the solution is uniform, and “bad” indicates that the sample does not become uniform. evaluated.

  [Coating property]: A photosensitive resin composition was spin-coated on a 6-inch silicon wafer, and then heated on a hot plate at 110 ° C. for 3 minutes to prepare a uniform coating film having a thickness of 20 μm. The prepared coating film was visually observed, and those having defects such as cracks were evaluated as “defective”, and those having no defects such as cracks were evaluated as “good”.

[Resolution]: Using an aligner (trade name “MA-150”, manufactured by Suss Microtec), UV light from a high-pressure mercury lamp through a pattern mask, and an exposure amount at a wavelength of 350 nm is 1,000 to 5,000 mJ. The wafer with a coating film obtained by the above-mentioned evaluation of “applicability” was exposed so as to be / cm ² . Subsequently, it heated at 110 degreeC for 3 minute (PEB) with the hotplate, and was developed by immersion for 60 seconds at 23 degreeC using the 2.38 mass% tetramethylammonium hydroxide aqueous solution. The minimum dimension (μm) of the obtained pattern was defined as “resolution”.

[Residual stress]: A photosensitive resin composition was spin-coated on an 8-inch silicon wafer, and then heated on a hot plate at 110 ° C. for 3 minutes to prepare a uniform coating film having a thickness of 20 μm. Further, an aligner (trade name “MA-150”, manufactured by Suss Microtec) was used, and the entire surface was exposed to ultraviolet rays from a high-pressure mercury lamp so that the exposure amount at a wavelength of 350 nm was 2,000 mJ / cm ² . Subsequently, it heated at 110 degreeC for 3 minute (PEB) with the hotplate, and heated at 300 degreeC for 2 hours in oven, and formed the cured film. The change in wafer curvature before and after the formed cured film was formed was measured under the trade name “FLX-2320-S” (manufactured by Toago Technology Co., Ltd.), and the residual stress (MPa) was calculated.

  [I-line transmittance]: A photosensitive resin composition was spin-coated on a 6-inch glass substrate and heated on a hot plate at 110 ° C. for 3 minutes to prepare a uniform coating film having a thickness of 20 μm. The UV transmittance was measured with a UV measuring instrument (trade name “V-550 UV / VIS Spectrophotometer”, manufactured by JAS.CO), and the transmittance at a wavelength of 365 nm (i-line transmittance (%)) was determined.

[Solvent Resistance]: A photosensitive resin composition was spin-coated on a 6-inch silicon wafer and heated on a hot plate at 110 ° C. for 3 minutes to prepare a uniform coating film having a thickness of 20 μm. Further, an aligner (trade name “MA-150”, manufactured by Suss Microtec) was used, and the entire surface was exposed to ultraviolet rays from a high-pressure mercury lamp so that the exposure amount at a wavelength of 350 nm was 2,000 mJ / cm ² . Then, it heated at 110 degreeC for 3 minute (PEB) with the hotplate, and heated at 300 degreeC for 2 hours in oven, and obtained the wafer with a cured film. The obtained wafer with a cured film was immersed in N-methyl-2-pyrrolidone (NMP) heated to 60 ° C. for 30 minutes, and the change rate of the film thickness was investigated. The case where the change rate of the film thickness was 3% or more was evaluated as “bad”, and the case where it was less than 3% was evaluated as “good”.

[Heat shock resistance]: A photosensitive resin composition is applied to a substrate 6 as shown in FIGS. 3 and 4 and heated on a hot plate at 110 ° C. for 3 minutes to produce a 10 μm thick resin coating on the conductor. did. 3 and 4, reference numeral 7 denotes a substrate, and reference numeral 8 denotes a copper foil. Then, using an aligner, the entire surface was exposed to ultraviolet rays from a high-pressure mercury lamp so that the exposure amount at a wavelength of 350 nm was 2,000 mJ / cm ² . Subsequently, it heated at 110 degreeC for 3 minute (PEB) with the hotplate, and heated at 300 degreeC for 2 hours in oven, and formed the cured film, and obtained the board | substrate with a cured film. The obtained substrate was subjected to a thermal shock resistance test for 500 cycles with a thermal shock tester (manufactured by Tabai Espec) at -55 ° C / 30 minutes to 150 ° C / 30 minutes as one cycle. The cured film was visually observed, and a case where a defect such as a crack occurred was evaluated as “bad”, and a case where a defect such as a crack did not occur was evaluated as “good”.

[Toughness]: After a photosensitive resin composition was spin-coated on a PET film, it was heated in an oven at 110 ° C. for 10 minutes. Further, using an aligner, the entire surface was exposed to ultraviolet rays from a high pressure mercury lamp so that the exposure amount at a wavelength of 350 nm was 2,000 mJ / cm ² . Subsequently, it heated at 110 degreeC for 10 minute (PEB) in oven, and also heated at 300 degreeC for 2 hours in oven, and formed the cured film. The formed cured film was peeled off from the PET film and cut into strips to prepare test pieces of 5 cm × 1 cm × 40 μm. When both ends of the produced test piece were stacked, the case where the test piece was cracked was evaluated as “bad”, and the case where the test piece was not cracked was evaluated as “good”.

(Synthesis Example 1)
To a 2 L separable flask, 145.7 g of monomer 4-1 represented by the following formula (4-1) and 600 g of NMP were added. Under stirring, diaminopolysiloxane represented by the following formula (5-1) (trade name “BY16-853C”, manufactured by Toray Dow Corning, amine equivalent: 400 (hereinafter also referred to as “monomer 5-1”)) 156.0 g was charged, and then 98.4 g of 4,4′-diamino-3,3′-dihydroxybiphenyl (hereinafter also referred to as “monomer 6-1”) represented by the following formula (6-1). It is. After stirring at 60 ° C. for 8 hours, the temperature was raised to 200 ° C. and dehydration reaction was performed for 5 hours. After completion of the reaction, the reaction mixture was poured into water, and the product was reprecipitated, filtered and vacuum dried to obtain 310 g of a polymer. The weight average molecular weight of the obtained polymer was 151000. Moreover, IR analysis was conducted and it confirmed that there was absorption of 1778 cm < ^-1 > which shows an imide.

(Synthesis Examples 2-6, Comparative Synthesis Examples 2-4)
Formula (4-1), Formulas (4-2) to (4-6), Formula (5-1), Formula (5-2), Formula (6-1), and Formula (5-1) 6-2) to (6-3) (monomer 4-1 to 4-6, monomer 5-1 to 5-2, and monomer 6-1 to 6-3) are represented in Table 1. A polymer was obtained in the same manner as in Synthesis Example 1 except that the combinations and amounts shown in 2 and 2 were used. The yield and weight average molecular weight of the obtained polymer are shown in Table 2. In addition, IR analysis was performed and it confirmed that there existed absorption of 1778 cm < ^-1 > which shows an imide about any polymer.

(Comparative Synthesis Example 1)
In a 2 L separable flask, 98.2 g of 4,4′-diamino-3,3′-dihydroxybiphenyl (hereinafter also referred to as “monomer 6-1”) represented by the following formula (6-1), and NMP 800g was charged. Under stirring, 101.8 g of monomer 4-1 represented by the following formula (4-1) was added and stirred at 60 ° C. for 8 hours, and then heated to 200 ° C. for dehydration reaction for 5 hours. After completion of the reaction, the reaction mixture was poured into water, and the product was reprecipitated, filtered and vacuum dried to obtain 165 g of a polymer. The weight average molecular weight of the obtained polymer was 104,000. Moreover, IR analysis was conducted and it confirmed that there was absorption of 1778 cm < ^-1 > which shows an imide.

(Example 1)
1. 100 parts of the polymer obtained in Synthesis Example 1, 120 parts of ethyl lactate, 20 parts of styryl-bis (trichloromethyl) -s-triazine, and hexamethoxymethylmelamine (trade name “Cymel 300”, manufactured by Mitsui Cytec Co., Ltd.) A photosensitive resin composition (Example 1) was prepared by mixing 5 parts. The evaluation result of the mixing property was “good”. Also, the coating property is “good”, the resolution (minimum dimension) is 30 μm, the residual stress is 9 MPa, the i-line transmittance is 81%, the solvent resistance is “good”, the thermal shock resistance is “good”, and the toughness Was “good”.

(Examples 2-6, Comparative Examples 1-4)
Photosensitive resin compositions (Examples 2 to 6 and Comparative Examples 1 to 4) were prepared in the same manner as in Example 1 except that the formulation shown in Table 3 was used. Table 4 shows measurement results and evaluation results of various physical property values.

<Solvent>
EL: ethyl lactate PGME: propylene glycol monomethyl ether NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone

<Crosslinking agent>
C-1: Hexamethoxymethylmelamine (trade name “Cymel 300”, manufactured by Mitsui Cytec)
C-2: Tetramethoxymethylglycoluril (trade name “Cymel 1174”, manufactured by Mitsui Cytec)

<Photosensitive acid generator>
D-1: styryl-bis (trichloromethyl) -s-triazine D-2: 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate

  The photosensitive resin composition containing the polymer of the present invention can be applied at a high film thickness, can be developed with an alkali, has high resolution, low residual stress after curing, solvent resistance, heat resistance Since a cured product excellent in various properties such as impact and adhesion can be obtained, it is suitable for surface protective film applications, interlayer insulating film applications, and insulating film applications for high-density mounting substrates, and is extremely useful industrially.

It is sectional drawing which shows typically an example of the semiconductor element which has the insulating resin layer formed using the photosensitive resin composition of this invention. It is sectional drawing which shows typically the other example of the semiconductor element which has the insulating resin layer formed using the photosensitive resin composition of this invention. It is sectional drawing which shows typically an example of the base material with which the photosensitive resin composition of this invention is apply | coated. It is a top view which shows typically an example of the base material with which the photosensitive resin composition of this invention is apply | coated.

Explanation of symbols

1: substrate, 2: metal pad, 3: insulating film, 4: metal wiring, 5: insulating film, 6: base material, 7: substrate, 8: copper foil

Claims (5)

A repeating unit having a structure represented by the following general formula (1);
A repeating unit having a structure represented by the following general formula (2);
A polymer having

(In the general formula (1), R ¹ represents a tetravalent alicyclic hydrocarbon group or a tetravalent alkyl alicyclic hydrocarbon group having an alkyl group having 1 to 4 carbon atoms (provided that R 1 ^{In the case where 1} is the above-described alkyl alicyclic hydrocarbon group, a tetravalent group that is simultaneously substituted by two or more from the same alkyl group is excluded.) A is represented by the following general formula (3). (Represents a divalent group)

(In the general formula (2), R ¹ has the same meaning as R ¹ in the general formula (1), and B represents a divalent group having a hydroxyl group).

(In said general formula (3), R < ² > shows the C1-C3 alkyl group or the aryl group which may have a substituent each independently, m is an integer of 1-10. N represents an integer of 1 to 30)   The polymer according to claim 1, wherein in the general formula (3), n = 1. (A) The polymer according to claim 1 or 2,
(B) a photosensitive acid generator, and (C) a crosslinking agent,
Containing a photosensitive resin composition.   The photosensitive resin composition according to claim 3, wherein the (C) crosslinking agent is a compound having an alkoxyalkylated amino group.   The cured film formed using the photosensitive resin composition of Claim 3 or 4.

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