JP5141552B2 - Polymer and photosensitive resin composition containing the same - Google Patents

Description

  The present invention relates to a polymer of a ring-closing polyimide used for an interlayer insulating film (passivation film), a surface protective film (overcoat film), an insulating film for a high-density mounting substrate, etc. of a semiconductor element, and a photosensitive material containing the same. The present invention relates to a resin composition. More specifically, the present invention provides a surface protective film and an interlayer insulating film that have high solubility in general solvents, can be applied to a high film thickness and can be developed with an alkali, and can obtain a cured product with high resolution. And a ring-closed polyimide polymer suitable for use as an insulating film for high-density mounting substrates, and a photosensitive resin composition containing the polymer.

  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. Also, various photosensitive polyimide-based resins imparted with photosensitivity for improving film formation accuracy due to high integration of semiconductor elements have been proposed, and side-chain polymerizable negative photosensitive polyimide is frequently used.

  For example, Patent Document 1 describes a photosensitive composition using an aromatic polyimide precursor having an acrylic side chain. However, this photosensitive composition has a problem that it is difficult to cope with a high film thickness due to a problem of light transmittance and a large residual stress after curing. Furthermore, there have been problems with the environment and safety due to solvent development. In addition, since it is necessary to use an organic solvent as a developing solution, development of an alkali development type radiation sensitive resin composition is desired.

  In order to solve these problems, many proposals have been conventionally made. For example, Patent Documents 2 and 3 propose a positive photosensitive polyimide composition that can be alkali-developed. However, the applicability of these photosensitive polyimide compositions is not necessarily good, and it has been difficult to cope with a high film thickness of, for example, 15 μm or more. Another problem is that it is difficult to obtain a sufficiently high resolution. For this reason, there is a problem that it is difficult to cope with the application of a surface protective film, an interlayer insulating film, and an insulating film for a high-density mounting substrate that require high film thickness coating and high resolution. 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.

JP 63-125510 A JP-A-3-204649 Japanese Patent Laid-Open No. 3-209478

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is high solubility in common solvents, and high-coating and alkali development are possible. In addition, a polymer of a ring-closed polyimide suitable for use as a surface protective film, an interlayer insulating film, and an insulating film for a high-density mounting substrate capable of obtaining a cured product with high resolution, and a photosensitive resin composition containing the same To provide things.

  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 and photosensitive resin composition are provided.

  [1] A polymer comprising a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (3).

（前記一般式（１）中、Ｘは４価の芳香族又は脂肪族炭化水素基を示し、Ａは下記一般式（２）で示される２価の基を示す）

(In the general formula (1), X represents a tetravalent aromatic or aliphatic hydrocarbon group, and A represents a divalent group represented by the following general formula (2)).

（前記一般式（２）中、Ｒ^１は２価の基を示し、Ｒ^２は互いに独立して、水素原子、アシル基、又はアルキル基を示し、ｎ^１及びｎ^２は０〜２の整数を示し、ｎ^１とｎ^２の少なくとも一方は１以上であり、Ｒ^２の少なくとも一つは水素原子である）

(In the general formula (2), R ¹ represents a divalent group, R ² independently represents a hydrogen atom, an acyl group, or an alkyl group, and n ¹ and n ² are integers of 0-2. And at least one of n ¹ and n ² is 1 or more, and at least one of R ² is a hydrogen atom)

（前記一般式（３）中、Ｘは４価の芳香族又は脂肪族炭化水素基を示し、Ｂは炭素数２〜２０の置換若しくは非置換のアルキレン基、又は下記一般式（４）で示される２価の基を示す）

(In the general formula (3), X represents a tetravalent aromatic or aliphatic hydrocarbon group, B represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms, or the following general formula (4). Represents a divalent group)

（前記一般式（４）中、Ｚは炭素数２〜２０の置換又は非置換のアルキレン基を示す）

(In the general formula (4), Z represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms)

  [2] The polymer according to [1], wherein X in the general formulas (1) and (3) is a tetravalent aliphatic hydrocarbon group.

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

  [4] The photosensitive resin composition according to [3], further including a phenol resin.

  [5] The photosensitive resin composition according to the above [3] or [4], wherein the (C) crosslinking agent has an alkoxyalkylated amino group.

  The novel ring-closed polyimide polymer of the present invention and the photosensitive resin composition containing the polymer have high solubility in general solvents, can be applied to a high film thickness and can be developed with alkali, and have high resolution. A cured product can be obtained, and the effect of being suitable for use as a surface protective film, an interlayer insulating film, and an insulating film for a high-density mounting substrate is achieved.

It is a schematic cross section of the semiconductor element which has the insulating resin layer formed using the photosensitive resin composition of this invention. It is a schematic cross section of the semiconductor element which has the insulating resin layer formed using the photosensitive resin composition of this invention.

Explanation of symbols

1: substrate, 2: metal pad, 3: insulating film, 4: metal wiring, 5: insulating film

  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:
The polymer (A) of the present invention comprises a repeating unit represented by the general formula (1) and a repeating unit represented by the general formula (3). The details will be described below.

  X in the general formula (1) is a tetravalent aromatic hydrocarbon group or a tetravalent aliphatic hydrocarbon group, preferably a tetravalent aliphatic hydrocarbon group. Specific examples of the tetravalent aromatic hydrocarbon group include a tetravalent group in which four hydrogens in the mother skeleton of the aromatic hydrocarbon are substituted.

  As an aromatic hydrocarbon group, the group shown below can be mentioned, for example.

  Examples of the tetravalent aliphatic hydrocarbon group include a chain hydrocarbon group, an alicyclic hydrocarbon group, and an alkyl alicyclic hydrocarbon group. More specifically, a tetravalent group in which four hydrogens in the base skeleton of a chain hydrocarbon group, an alicyclic hydrocarbon, or an alkyl alicyclic hydrocarbon are substituted can be given. These tetravalent aliphatic hydrocarbon groups may contain an aromatic ring in at least a part of the structure. Here, examples of the chain hydrocarbon include ethane, n-propane, n-butane, n-pentane, n-hexane, n-octane, n-decane, and n-dodecane. Specific examples of the alicyclic hydrocarbon include a monocyclic hydrocarbon group, a bicyclic hydrocarbon group, and a tricyclic or higher hydrocarbon.

Examples of monocyclic hydrocarbons 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.

  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. More specifically, methylcyclopentane, 3-ethyl-1-methyl-1-cyclohexene, 3-ethyl-1-cyclohexene and the like can be mentioned. The tetravalent aliphatic hydrocarbon group containing an aromatic ring in at least a part of the structure preferably has 3 or less aromatic rings in one molecule. It is particularly preferable that More specifically, 1-ethyl-6-methyl-1,2,3,4-tetrahydronaphthalene, 1-ethyl-1,2,3,4-tetrahydronaphthalene and the like can be mentioned.

As a mother nucleus of a tetravalent group preferable as X, n-butane, 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.

  More preferred as X is

である。

It is.

  Particularly preferred as X is

であり、最も好ましいのは、

And most preferred

である。これらのＸは、一種単独で又は二種以上を組み合わせて用いることができる。

It is. These X can be used individually by 1 type or in combination of 2 or more types.

A in the general formula (1) is a divalent group represented by the general formula (2). R ¹ in the general formula (2) is a divalent group. Specific examples of R ¹ include oxygen atom, sulfur atom, sulfone group, carbonyl group, methylene group, alkylene group (excluding methylene group), dimethylmethylene group, bis (trifluoromethyl) methylene group and the like. .

R ² in the general formula (2) independently represents a hydrogen atom, an acyl group or an alkyl group. Preferred acyl groups include formyl group, acetyl group, propionyl group, butyroyl group, isobutyroyl group and the like. Preferred alkyl groups include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n -Butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-decyl group, n-dodecyl group and the like can be mentioned. Note that at least one of R ² is a hydrogen atom. Further, ^{n 1} and ^{n 2} in the general formula (2) is an integer of 0 to 2, at least one of ^{n 1} and ^{n 2} is 1 or more.

  Preferred as A is

である。また、Ａとして更に好ましいのは、

It is. Further, more preferable as A is

である。

It is.

  X in the general formula (3) is a tetravalent aromatic hydrocarbon group or a tetravalent aliphatic hydrocarbon group. X in this general formula (3) is the same as X in the said general formula (1), and the same thing can be mentioned as a suitable example.

  B in the general formula (3) is a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms, or a divalent group represented by the general formula (4). Specifically, the substituted or unsubstituted alkylene group having 2 to 20 carbon atoms is preferably an alkylene group having 4 or more carbon atoms. Examples of the alkylene group having 4 or more carbon atoms include alkylene groups having 4 carbon atoms such as 1,4-butylene group; alkylene groups having 5 carbon atoms such as 1,5-pentylene group; 2-methyl-1,5- Examples thereof include alkylene groups having 6 carbon atoms such as pentylene group and 1,6-hexylene group; alkylene groups having 7 to 20 carbon atoms such as 1,10-decylene group and 1,12-dodecylene group. Among these, an alkylene group having 6 or more carbon atoms is preferable, and an alkylene group having 7 to 20 carbon atoms is more preferable because the solubility of the polymer in a solvent is improved.

  Z in the general formula (4) is a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms. Specifically, the substituted or unsubstituted alkylene group having 2 to 20 carbon atoms is preferably an alkylene group having 3 or more carbon atoms. Examples of the alkylene group having 3 or more carbon atoms include alkylene groups having 3 to 5 carbon atoms such as 1,3-propylene group, 2,2-dimethylpropylene group, 1,4-butylene group and 1,5-pentylene group. An alkylene group having 6 carbon atoms such as 2-methyl-1,5-pentylene group and 1,6-hexylene group; an alkylene group having 7 to 20 carbon atoms such as 1,10-decylene group and 1,12-dodecylene group; Etc.

  More preferable as the divalent group represented by the general formula (4) is

である。

It is.

  (A) The polymer is usually a monomer represented by the following general formula (5) (hereinafter also referred to as “monomer (5)”), a monomer represented by the following general formula (6) (hereinafter referred to as “monomer (6)”). And a monomer represented by the following general formula (7) (hereinafter also referred to as “monomer (7)”) in a polymerization solvent to synthesize a polyamic acid, and further carry out an imidization reaction. Can be obtained. The following two types of methods are generally known for synthesizing a polyamic acid, and any method may be used for synthesis. That is, (i) a method in which the monomer (6) and the monomer (7) are dissolved in the polymerization solvent and then the monomer (5) is reacted; (ii) after the monomer (5) is dissolved in the polymerization solvent, the monomer ( 7) is reacted, and the monomer (6) is further reacted.

X in the general formula (5) is the same as X in the general formula (1), and R ¹ , R ² , n ¹ , and n ² in the general formula (6) are It is the same as R ¹ , R ² , n ¹ and n ^{2 in the} general formula (2), and B in the general formula (7) is the same as B in the general formula (3).

  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, alcohol solvents such as methanol, ethanol, propanol, butanol, 2-methoxyethanol, 2-ethoxyethanol, 2- (2-methoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethanol; diglyme , Ether solvents such as triglyme; aromatic hydrocarbon solvents such as toluene and xylene may be added.

  As the imidization reaction, a heating imidization reaction and a chemical imidation reaction are generally known, but it is preferable to synthesize a polymer (A) by a heating imidization reaction. The heating imidization reaction is usually performed by heating a synthesis solution of polyamic acid 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 about 2,000 to 500,000, preferably 3, It is about 000-200,000. 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 of the photosensitive resin composition obtained by using the polymer (A) in a solvent or a developer tends to be poor.

  (A) The ratio of the monomer (5) in the total monomer (monomer (5) + monomer (6) + monomer (7)) of the polymer is usually 40 to 60 mol%, preferably 45 to 55 mol. %. When the proportion of the monomer (5) in the total monomer is less than 40 mol% or more than 60 mol%, the molecular weight of the resulting (A) polymer tends to decrease. Moreover, the ratio of the monomer (6) with respect to the sum total of a monomer (6) and a monomer (7) is 10-99 mol% normally, Preferably it is 20-95 mol%, More preferably, it is 30-90 mol%. It is.

2. Photosensitive resin composition:
Next, the photosensitive resin composition of the present invention will be described. The photosensitive resin composition of the present invention contains the above-mentioned (A) polymer, (B) a photoacid generator, and (C) a crosslinking agent. The details will be described below.

((B) Photoacid generator)
The (B) photoacid generator 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”). (B) Photoacid generators having such properties include iodonium salt compounds, sulfonium salt compounds, sulfone compounds, sulfonate ester compounds, halogen-containing compounds, sulfonimide compounds, diazomethane compounds, and other chemically amplified photoacids. Generators: There are naphthoquinone diazide (NQD) photoacid generators such as diazoketone compounds.

  Examples of the iodonium salt compound include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluorobutanesulfonate, diphenyliodonium pyrenesulfonate, 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, and the like.

  Examples of the sulfonium salt compounds include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium camphorsulfonate, triphenylsulfonium naphthalenesulfonate, 4-hydroxyphenyl benzylmethylsulfonium p-toluenesulfonate, 4- ( Phenylthio) phenyl diphenylsulfonium hexafluorophosphate, 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4,7-di-n-hydroxy-1-naphthyltetrahydrothiophenium trifluoro Lomethanesulfonate, 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium hexafur Rofosufeto, mention may be made of 4-n-butoxy-1-naphthyl tetrahydrothiophenium trifluoromethanesulfonate, and the like.

  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.

  Examples of the sulfonate compound include alkyl sulfonate, haloalkyl sulfonate, aryl sulfonate, and imino sulfonate. 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.

  Examples of the halogen-containing compound include haloalkyl group-containing hydrocarbon compounds and haloalkyl group-containing heterocyclic compounds. Specific examples of preferred halogen-containing compounds include 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane, phenyl-bis (trichloromethyl) -s-triazine, 4-methoxyphenyl-bis (trichloromethyl). ) -S-triazine, styryl-bis (trichloromethyl) -s-triazine, 4-methoxystyryl-bis (trichloromethyl) -s-triazine, naphthyl-bis (trichloromethyl) -s-triazine, or the following general formula The s-triazine derivative represented by (8) can be mentioned.

In the general formula (8), R ³ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxyl group having 1 to 4 carbon atoms, Y represents a halogen atom, and Q represents an oxygen atom or a sulfur atom. Indicates.

The s-triazine derivative represented by the general formula (8) has wide absorption in the g-line, h-line, and i-line regions, and is compared with other general radiation-sensitive acid generators having other triazine skeletons. Thus, an insulating cured product having high acid generation efficiency and a high residual film ratio can be obtained. In the general formula (8), examples of the alkyl group having 1 to 4 carbon atoms represented by R ³ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an iso-butyl group. , Sec-butyl group, tert-butyl group and the like. Examples of the alkoxyl group having 1 to 4 carbon atoms include methoxy group, ethoxy group, propoxy group, isopropoxy group, n-butoxy group, iso-butoxy group, sec-butoxy group and the like. Note that R ³ in the general formula (8) is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom, a methyl group, or an ethyl group.

  In the general formula (8), the halogen atom represented by Y is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and more preferably a chlorine atom. Furthermore, Q in the general formula (8) is more preferably an oxygen atom.

Specific examples of the s-triazine derivative represented by the general formula (8) include 2- [2- (furan-2-yl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine (Q = O, R ³ = H, Y = Cl), 2- [2- (5-methylfuran-2-yl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine (Q = O, R ³ = CH ₃ , Y = Cl) and the like. In addition, these s-triazine derivatives can be used individually by 1 type or in combination of 2 or more types.

  Examples of the sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N- (trifluoromethylsulfonyloxy) bicyclo. [2.2.1] Hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthylimide and the like can be mentioned.

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

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

  Among the above-mentioned compounds, sulfonium salt compounds, sulfone compounds, halogen-containing compounds, diazoketone compounds, sulfonimide compounds and diazomethane compounds are preferable, and sulfonium salt compounds and halogen-containing compounds are more preferable. 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 hexafluorophosphate, 4-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-methoxyphenyl-bis (trichloromethyl) -s-triazine, styryl-bis (trichloromethyl) -s-triazine, 4-methoxystyryl-bis (trichloromethyl) -s-triazine. In addition, these (B) photo-acid generators can be used individually by 1 type or in combination of 2 or more types.

  (B) The content ratio of the photoacid generator is based on 100 parts by mass of the polymer (A) (however, when the polymer other than the polymer (A) is further contained, the polymer (A) And 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass, based on 100 parts by mass of the total of other polymers. If it is less than 0.1 part by mass, it may be difficult to cause a chemical change due to the catalytic action of the acid generated by exposure. On the other hand, when it is more than 20 parts by mass, there is a possibility that coating unevenness may occur when applying the photosensitive resin composition, or insulation after curing may decrease.

((C) Crosslinking agent)
(C) The crosslinking agent 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. 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. Of these, compounds having an alkoxyalkylated amino group are preferred. In addition, these (C) crosslinking agents can be used individually by 1 type or in combination of 2 or more types.

  Examples of polyfunctional (meth) acrylate compounds include trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth). ) Acrylate, dipentaerythritol hexa (meth) acrylate, glycerol 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) acrylate And diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, bis (2-hydroxyethyl) isocyanurate di (meth) acrylate, and the like. it can.

  Examples of the epoxy compound include novolak type epoxy resins, bisphenol type epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins.

  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.

  Examples of the compound having an alkoxyalkylated amino group include (poly) methylolated melamine, (poly) methylolated glycoluril, (poly) methylolated benzoguanamine, (poly) methylolated urea, and the like. And a nitrogen-containing compound having an active methylol group, wherein at least one hydrogen atom of the hydroxyl group of the methylol group is substituted with an alkyl group such as a methyl group or a butyl group. In addition, the compound having an alkoxyalkylated amino group may be a mixture of a plurality of substituted compounds, and some of them contain an oligomer component that is partially self-condensed. Can do.

  More specific examples of the compound having an alkoxyalkylated amino group include compounds represented by the following formulas (9) to (15).

  In addition, the compound represented by the formula (9) (hexakis (methoxymethyl) melamine) is commercially available under the trade name “Cymel 300” (manufactured by Cytec Industries). Further, the compound represented by the formula (11) (tetrakis (butoxymethyl) glycoluril) is commercially available under the trade name “Cymel 1170” (manufactured by Cytec Industries).

  Compounds having an alkoxyalkylated amino group include hexakis (methoxymethyl) melamine (formula (9)), tetrakis (methoxymethyl) glycoluril (formula (12)), tetrakis (butoxymethyl) glycoluril ( The formula (11)) is particularly preferable, and hexakis (methoxymethyl) melamine (the formula (9)) is most preferable.

  (D) The content rate of a crosslinking agent is suitably set so that it may become the quantity which the film | membrane formed with the photosensitive resin composition fully hardens | cures. Specifically, the content ratio of the (D) crosslinking agent is (A) based on 100 parts by mass of the polymer (however, when (A) other polymer other than the polymer is further contained, (A ) In general, it is 5 to 50 parts by mass, preferably 10 to 40 parts by mass, based on 100 parts by mass of the polymer and other polymers. If it is less than 5 parts by mass, the resulting insulating layer may have insufficient solvent resistance and plating solution resistance. On the other hand, if it exceeds 50 parts by mass, the developability of the thin film formed by the photosensitive resin composition may be insufficient.

(Other polymers (resins))
The photosensitive resin composition of the present invention may further contain other polymer (resin) other than the above-mentioned (A) polymer, if necessary, within a range not impairing the effects of the present invention. The “other polymer (resin)” that can be contained is not particularly limited, but is preferably an alkali-soluble one, and further an alkali-soluble resin having a phenolic hydroxyl group (hereinafter also referred to as “phenol resin”). It is more preferable to contain it because the resolution becomes good.

  Examples of the phenol resin that can be contained include novolak resin, polyhydroxystyrene and copolymers thereof, phenol-xylylene glycol dimethyl ether condensation resin, cresol-xylylene glycol dimethyl ether condensation resin, phenol-dicyclopentadiene condensation resin, and the like. be able to.

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

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

  Monomers other than hydroxystyrene constituting the copolymer of polyhydroxystyrene are not particularly limited. Specifically, styrene, indene, p-methoxystyrene, p-butoxystyrene, p-acetoxystyrene, p-hydroxy- Styrene derivatives such as α-methylstyrene; (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, sec -(Meth) acrylic acid derivatives such as butyl (meth) acrylate and t-butyl (meth) acrylate; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-butyl vinyl ether and t-butyl vinyl ether; maleic anhydride, italy anhydride It can be exemplified acid anhydride derivatives such as phosphate.

  The content ratio of the phenol resin is preferably 0 to 90 parts by mass, more preferably 5 to 80 parts by mass, and more preferably 10 to 70 parts by mass with respect to 100 parts by mass in total of the (A) polymer and the phenol resin. It is particularly preferable to use parts by mass. When the amount is less than 5 parts by mass, the effect of containing this phenol resin tends to be hardly exhibited. On the other hand, if it exceeds 90 parts by mass, the mechanical strength of the film tends to decrease.

  Furthermore, the photosensitive resin composition of the present invention may contain a phenolic low molecular compound in addition to the above-described phenol resin. Specific examples of the phenolic low molecular weight compound that can be contained include 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenyl ether, tris (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxy). Phenyl) -1-phenylethane, tris (4-hydroxyphenyl) ethane, 1,3-bis [1- (4-hydroxyphenyl) -1-methylethyl] benzene, 1,4-bis [1- (4- Hydroxyphenyl) -1-methylethyl] benzene, 4,6-bis [1- (4-hydroxyphenyl) -1-methylethyl] -1,3-dihydroxybenzene, 1,1-bis (4-hydroxyphenyl) -1- [4- {1- (4-hydroxyphenyl) -1-methylethyl} phenyl] ethane, 1,1,2,2- Tiger (4-hydroxyphenyl) ethane and the like.

  The content ratio of the phenolic low molecular compound is (A) 100 parts by mass of the polymer (however, in the case of further containing other polymer than (A) polymer, (A) polymer and other polymer) Is preferably 0 to 100 parts by mass, more preferably 1 to 60 parts by mass, and particularly preferably 5 to 40 parts by mass. When the amount is less than 1 part by mass, the effect of containing this phenolic low-molecular compound tends to be hardly exhibited. On the other hand, if it exceeds 100 parts by mass, the mechanical strength of the film tends to decrease.

(solvent)
In the photosensitive resin composition of the present invention, in order to improve the handleability and to adjust the viscosity and storage stability, the organic resin is used as necessary within a range not impairing the effects of the present invention. A solvent can be contained. Although the kind of solvent which can be contained is not specifically limited, For example, aprotic solvents, such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, (gamma) butyrolactone, dimethylsulfoxide; A phenolic protic solvent such as metacresol is preferably used.

  Further, the photosensitive resin composition of the present invention includes propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, propylene glycol monoalkyl ether acetates, aliphatic alcohols instead of or together with the above solvents. Organic solvents such as lactic acid esters, lactic acid esters, aliphatic carboxylic acid esters, alkoxy aliphatic carboxylic acid esters, and ketones.

  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. Examples of propylene glycol dialkyl ethers include propylene glycol diethyl ether, propylene glycol dipropyl ether, and propylene glycol dibutyl ether.

  Examples of 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. Examples of aliphatic alcohols include 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 4-methyl-2-pentanol, 1-hexanol and the like.

  Examples of lactic acid esters include methyl lactate, ethyl lactate, n-propyl lactate, and isopropyl lactate. 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 isobutyl propionate. Can do.

  Examples of the alkoxy aliphatic carboxylic acid esters include methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate and the like. Examples of ketones include 2-heptanone, 3-heptanone, 4-heptanone, cyclopentanone, and cyclohexanone.

  Of these solvents, ethyl lactate, 2-heptanone, cyclohexanone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate and butyl acetate are preferred, and ethyl lactate and propylene glycol monomethyl ether are particularly preferred. These solvents can be used singly or in combination of two or more. In addition, a solvent is normally used so that the total content rate of components other than a solvent may be 1-60 mass%.

(Other additives)
The photosensitive resin composition of the present invention can contain other additives such as a basic compound, an adhesion assistant, and a surfactant, as necessary, as long as the effects of the present invention are not impaired. .

(Basic compound)
Examples of the basic compound include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, Examples thereof include trialkylamines such as tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine and n-dodecyldimethylamine, and nitrogen-containing heterocyclic compounds such as pyridine, pyridazine and imidazole. Content of a basic compound is 5 mass parts or less normally with respect to 100 mass parts of (A) polymers, Preferably it is 3 mass parts or less. If the content of the basic compound is more than 5 parts by mass with respect to 100 parts by mass of the polymer (A), the photoacid generator may not function sufficiently.

(Adhesion aid)
The photosensitive resin composition of the present invention may contain an adhesion assistant in order to improve the adhesion to the substrate. A functional silane coupling agent is effective as the adhesion assistant. Here, the functional silane coupling agent refers to a silane coupling agent having a reactive substituent such as a carbonyl group, a methacryloyl group, an isocyanate group, or an epoxy group. Specific examples include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxylane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, β -(3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like can be mentioned. The content of the adhesion assistant is preferably 10 parts by mass or less with respect to 100 parts by mass of the polymer (A).

(Surfactant)
The photosensitive resin composition of the present invention may contain a surfactant for the purpose of improving various properties such as coating properties, defoaming properties, and leveling properties. Examples of the surfactant include BM-1000, BM-1100 (manufactured by BM Chemie), MegaFuck F142D, F172, F173, F183 (manufactured by Dainippon Ink & Chemicals, Inc.), Florard FC. -135, FC-170C, FC-430, FC-431 (above, manufactured by Sumitomo 3M), Surflon S-112, S-113, S-131, S-141, S-145 (Above, manufactured by Asahi Glass Co., Ltd.), SH-28PA, -190, -193, SZ-6032, SF-8428 (above, manufactured by Toray Dow Corning Silicone), etc. Agents can be used. The content of the surfactant is preferably 5 parts by mass or less with respect to 100 parts by mass of the polymer (A).

  In particular, the photosensitive resin composition according to the embodiment of the present invention can be suitably used as a surface protective film or an interlayer insulating film material of a semiconductor element. The photosensitive resin composition according to the embodiment of the present invention is applied to a support (a copper foil with resin, a copper wafer with a copper clad laminate, a silicon wafer with a metal sputtered film, an alumina substrate, etc.), and dried to volatilize a solvent or the like. To form a coating film. Then, it exposes through a desired mask pattern, heat processing (henceforth this heat processing is called "PEB") is performed, and reaction with a phenol ring and a crosslinking agent is accelerated | stimulated. Subsequently, it develops with an alkaline developing solution, A desired pattern can be obtained by melt | dissolving and removing an unexposed part. Furthermore, a cured film can be obtained by performing a heat treatment in order to develop insulating film characteristics.

  As a method for applying the photosensitive resin composition to the support, for example, a coating method such as a dipping method, a spray method, a bar coating method, a roll coating method, or a spin coating method can be used. The coating thickness can be appropriately controlled by adjusting the coating means and the solid content concentration and viscosity of the composition solution. After coating, in order to volatilize the solvent, a pre-bake treatment is usually performed. The conditions vary depending on the blending composition of the photosensitive resin composition, the used film thickness, and the like, but are usually 70 to 150 ° C., preferably 80 to 140 ° C., and about 1 to 60 minutes.

Examples of radiation used for exposure include low-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, ultraviolet rays such as g-line and i-line, electron beams, and laser beams. The exposure amount is appropriately selected depending on the light source to be used, the resin film thickness, and the like. For example, when irradiating ultraviolet rays from a high-pressure mercury lamp, the exposure film thickness is usually about 100 to 5000 mJ / cm ² when the resin film thickness is 10 to 50 μm.

  After the exposure, PEB is performed in order to promote the curing reaction between the phenol ring and the (C) crosslinking agent by the generated acid. The PEB conditions vary depending on the composition of the photosensitive resin composition, the film thickness used, etc., 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 in this case include a shower developing method, a spray developing method, an immersion developing method, and a paddle developing method. The development conditions are usually about 20 to 40 ° C. and about 1 to 10 minutes.

  As the alkaline developer, for example, an alkaline compound in which an alkaline compound such as sodium hydroxide, potassium hydroxide, ammonia water, tetramethylammonium hydroxide, choline, etc. is dissolved in water so as to have a concentration of about 1 to 10% by mass. An aqueous solution can be mentioned. An appropriate 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. In addition, after developing with an alkaline developer, it is washed with water and dried.

  Furthermore, in order to sufficiently develop the characteristics as an insulating film after development, the film can be sufficiently cured by heat treatment. Such curing conditions are not particularly limited, but the photosensitive resin composition can be cured by heating at a temperature of 100 to 400 ° C. for about 30 minutes to 10 hours depending on the use of the cured product. Can do. Moreover, in order to fully advance hardening or to prevent the deformation | transformation of the obtained pattern shape, it can also heat in multiple steps. For example, when it is performed in two stages, the first stage is heated at a temperature of 50 to 200 ° C. for about 5 minutes to 2 hours, and the second stage is performed at a temperature of 100 to 400 ° C. for about 10 minutes to 10 hours. It can also be cured by heating.

  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 embodiment of the present invention will be described with reference to the drawings. 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. Thus, if the photosensitive resin composition which is this embodiment is used, the semiconductor element which has the insulating resin layer formed with this photosensitive resin composition can be obtained.

  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.

  [Molecular weight (Mw)]: Tosoh GPC column (one TSKgel α-M, one TSKgel α-2500), flow rate: 1.0 ml / min, elution solvent: N, N-dimethylformamide, column Temperature: Measurement was performed by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of 35 ° C.

  [Mixability]: When each component was mixed at the composition ratio shown in Table 3, a transparent and uniform solution was judged as “good”, and a translucent or opaque solution was judged as “bad”. .

  [Coating property]: 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. The case where defects such as cracks occurred in the coating film was evaluated as “bad”, and the case where defects such as cracks did not occur was determined as “good”.

[Patterning property]: Using an aligner (MAS-150 manufactured by Suss Microtec), UV light from a high-pressure mercury lamp through a pattern mask so that the exposure amount at a wavelength of 350 nm is 1000 to 5000 mJ / cm ^2. The wafer with a coating film obtained in (1) was exposed. 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 case where the pattern was formed according to the mask was “good”, and the case where the pattern was not formed according to the mask was “bad”.

(Synthesis Example 1)
In a 500 mL separable flask, 2,2-bis (3-amino-4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane (monomer “MA-1”) 41. 1 g, 19.4 g of 1,10-decylylenediamine (monomer “MB-1”) and 195 g of N-methyl-2-pyrrolidone (hereinafter referred to as “NMP”) were added. After stirring at room temperature to dissolve each monomer, 44.5 g of 1,2,3,4-butanetetracarboxylic dianhydride (monomer “MC-2”) was charged. After stirring at 120 ° C. for 5 hours under nitrogen, the temperature was raised to 180 ° 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 91 g of a polymer. The molecular weight Mw of the obtained polymer was 23100. Moreover, IR analysis was conducted and it confirmed that there was absorption of 1778 cm < ^-1 > which shows an imide.

(Synthesis Examples 2 to 7)
A polymer was obtained in the same manner as in Synthesis Example 1 except that each monomer and NMP were blended in the molar ratio shown in Table 1 and the mass shown in Table 2. Table 2 shows the yield (g) and molecular weight Mw of the obtained polymer. Moreover, about any obtained polymer, it was confirmed by IR analysis that there was 1778 cm < ^-1 > absorption which shows an imide. The structure of the monomer used in each synthesis example is shown below.

Example 1
100 parts by mass of the polymer obtained in Synthesis Example 1, 170 parts by mass of a solvent (ethyl lactate (EL)), 1.5 parts of a photoacid generator (B-1), and 15 parts of a crosslinking agent (C-1) By mixing, the photosensitive resin composition (Example 1) was obtained. Evaluation of the mixing property of the obtained photosensitive resin composition was “good”, evaluation of coating property was “good”, and evaluation of patterning property was “good”.

(Examples 2 to 11, Comparative Example 1)
A photosensitive resin composition (Examples 2 to 11 and Comparative Example 1) was obtained in the same manner as in Example 1 except that the formulation shown in Table 3 was used. Table 4 shows the evaluation of the mixing property, coating property, and patterning property of the obtained photosensitive resin composition. The meanings of the abbreviations in Table 3 are as shown below.

(Phenolic resin)
Cresol novolak resin comprising P-1: m-cresol / p-cresol = 60/40 (molar ratio) (polystyrene equivalent weight average molecular weight = 8,700)
P-2: Phenol / xylylene glycol dimethyl ether condensation resin (Mitsui Chemicals, trade name: Millex (registered trademark) XLC-3L)

(solvent)
EL: Ethyl lactate

(Photoacid generator)
B-1: Styryl-bis (trichloromethyl) -s-triazine B-2: 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate B-3: 2-2 [-(furan -2-yl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine (manufactured by Sanwa Chemical Co., Ltd., trade name: TFE-triazine)
B-4: 2- [2- (5-Methylfuran-2-yl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine (manufactured by Sanwa Chemical Co., Ltd., trade name: TME-triazine)

(Crosslinking agent)
C-1: Hexamethoxymethylmelamine (Cytech Industries, trade name: Cymel 300)
C-2: Tetramethoxymethylglycoluril (manufactured by Cytec Industries, trade name: Cymel 1174)
C-3: manufactured by Japan Epoxy Resin Co., Ltd., trade name: Epicoat (registered trademark) 828

  The polymer of this invention and the photosensitive resin composition containing this are suitable for a use of a surface protective film, an interlayer insulation film, and the insulating film for high-density mounting boards, and are very useful industrially.

Claims (5)

A polymer comprising a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (3).

(In the general formula (1), X represents a tetravalent aromatic or aliphatic hydrocarbon group, and A represents a divalent group represented by the following general formula (2)).

(In the general formula (2), R ¹ represents a divalent group, R ² independently represents a hydrogen atom, an acyl group, or an alkyl group, and n ¹ and n ² are integers of 0-2. And at least one of n ¹ and n ² is 1 or more, and at least one of R ² is a hydrogen atom)

(In the general formula (3), X represents a tetravalent aromatic or aliphatic hydrocarbon group, B represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms, or the following general formula (4). Represents a divalent group)

(In the general formula (4), Z represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms)   The polymer according to claim 1, wherein X in the general formulas (1) and (3) is a tetravalent aliphatic hydrocarbon group. (A) The polymer according to claim 1 or 2,
(B) a photoacid generator, and (C) a crosslinking agent,
Containing a photosensitive resin composition.   The photosensitive resin composition of Claim 3 which further contains a phenol resin.   The photosensitive resin composition according to claim 3 or 4, wherein the (C) crosslinking agent has an alkoxyalkylated amino group.

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