JPH07140659A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin film having high sensitivity, which is not swollen in development and capable of being easily patterned by incorporating specified polymer and photosensitive acid generating agent. CONSTITUTION:A polymer A shown by the formula and a photosensitive acid generating agent are incorporated. In the formula, X is tetravalent org. groups contg. aromatic or aliphatic ring, Y is bivalent org. groups, R<1>... R<3> can be the same or different and are hydrogen atom or 1-10C unsubstituted or substituted monovalent hydrocarbonic groups, respectively. Meanwhile, the polymer A is easily synthesized by using the diamine component and tetracarboxylic dianhydride which are commonly used as the polyimide resin raw material without need to use a diamine component such as a diamine having phenol group, and consequently the composition is extremely practical.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photosensitive resin composition useful for forming a protective film for heat-resistant parts such as a protective insulating film for semiconductor devices, an alignment film for liquid crystal display devices, and an insulating film for multilayer printed boards. Regarding things.

[0002]

2. Description of the Related Art Polyimide-based materials have been widely known as heat-resistant photosensitive materials. For example, a material containing polyamic acid and dichromate (Japanese Patent Publication No. 49-17374).
(Japanese Patent Application Laid-open No. JP-A-2004-115), a material comprising a photosensitive group introduced into the carboxyl group of polyamic acid by an ester bond (JP-A-49-115541 and JP-A-55-45746), and an amide bond to the carboxyl group of the polyamic acid. A material comprising a photosensitive group introduced by
-100143), a material comprising a photosensitive group introduced into the carboxyl group of a polyamic acid by a silyl ester bond (JP-A-62-275129), and a material comprising a polyamic acid and an amine compound having a photosensitive group (special JP-A-54-145794) and the like are known.

However, these materials are mixed with ionic impurities (Japanese Patent Publication No. Sho 49-17374, Japanese Patent Laid-Open No. Sho 49-74).
115541), swelling of the film during development (JP-A-49-115541, JP-A-55-45746).
JP-A-60-100143), sensitivity stability (JP-A-62-275129, JP-A-54-1).
(Japanese Patent No. 45794).

[0004]

Therefore, in order to improve the above problems, for example, a positive photosensitive resin composition (Polymer Enginee) prepared by blending a naphthoquinone diazide sulfonic acid ester with a polyimide resin having a phenol group.
ring And Science, July 1989 Vol.29, 954), a positive type photosensitive resin composition obtained by blending a photosensitive acid generator with a polyimide resin having a silylated phenol group (JP-A-4-110348). ) Etc. have been proposed.

However, in these methods, a diamine having a phenol group, which is a very special compound, must be used to form a polyimide resin, and the cost disadvantage is inevitable. Further, in the polyimide film formed by using these compositions, since the phenol group remains, the water absorption of the film formed by post-curing is very large, making it difficult to apply to electronic parts and the like. There is a problem such as.

Therefore, the object of the present invention is not limited to a polyimide resin formed by using a specific diamine component, can be applied to a wide range of polyimide resin raw materials, has a good sensitivity, and is a film formed by development. Is to provide a positive photosensitive resin composition which does not swell and has excellent resolution.

[0007]

According to the present invention, (A)
The following general formula (1):

[Chemical 2] In the formula, X is a tetravalent organic group containing an aromatic ring or an aliphatic ring, Y is a divalent organic group, and R ¹ , R ² and R ³ may be the same or different and each is hydrogen. A polymer having a structural unit represented by an atom or an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and (B)
Provided is a photosensitive resin composition, which comprises a photosensitive acid generator.

[0008]

In the photosensitive resin composition of the present invention, the polymer of the component (A) is a polyimide precursor, which is dehydrated and cyclized by heating to form a polyimide, and a silyl ester is contained in its constituent unit. based on (-COOSiR ¹ R ²
R ³ ) is a remarkable feature (see general formula (1)).

That is, in the present invention, the photosensitive acid generator generates an acid upon irradiation with an active energy ray such as light.
Therefore, in the light-irradiated portion of the composition, the silyl ester group is decomposed by the generated acid, and (A)
A carboxylic acid group (--COO) in the constituent unit of the component polymer.
H) is rapidly formed, and this portion is dissolved and removed with an alkaline developer. Therefore, a positive type film of a polyimide precursor is obtained by irradiating light or the like through an appropriate mask and performing alkali development, and by curing this, a polyimide film is formed.

In the present invention, the polymer as the component (A) can be easily synthesized by using a diamine component and a tetracarboxylic dianhydride which are generally used as a raw material for a polyimide resin, and a phenol group is used. It is not necessary to use a special diamine component such as a diamine having, and is extremely practical.

Further, this composition has good sensitivity to light irradiation and can form a pattern quickly by alkali development, so that there is no problem such as swelling of the film during this development.

Moreover, in this composition, during the preparation of the composition, over the steps of exposure, formation of a positive film, and curing, a carboxylic acid group is formed without forming a phenol group in the polymer. Since the carboxylic acid group is easily converted to an imide group by heating during post-curing, the problem caused by the phenol group present in the film as in the above-mentioned prior art is effectively solved.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION (A) Polymer In the photosensitive resin composition of the present invention, the polymer of the component (A) is the polyimide precursor as described above, and the acid is dehydrated and ring-closed to cause heat resistance. A polyimide resin having excellent properties is formed.

The polymer is composed of the constitutional unit represented by the general formula (1), and has particularly good photosensitivity,
From the standpoint of storage stability, physical properties of the film after curing, etc., the number of the constituent units is preferably 10 or more, more preferably 20 or more. Further, other polyamic acid units may be contained as long as the object of the present invention is not impaired.

The polymer comprising the constitutional unit represented by the general formula (1) can be synthesized, for example, by a method known per se. For example, according to the disclosure of JP-B-43-18790, General formula (2): O (CO) ₂ X (CO) ₂ O (2) In the formula, X is as described above, and tetracarboxylic dianhydride represented by the following general formula (3) R ³ R ² R ¹ —HN—Si—NH—R ¹ R ² R ³ (3) In the formula, Y and R ^{1 to} R ³ are as described above, and a silylated diamine represented by Obtained by polycondensation reaction.

That is, in the general formula (1), X, which is a tetravalent organic group, is a residue of the tetracarboxylic acid dianhydride represented by the general formula (2), which is an aromatic ring or an aliphatic ring. It contains a ring. Representative examples thereof include, but are not limited to, the following.

[0017]

[Chemical 3]

The tetracarboxylic acid dianhydride of the general formula (2) corresponding to the tetravalent organic group X exemplified above is pyromellitic dianhydride, benzophenonetetracarboxylic acid dianhydride, and 3,3, respectively. ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2-bis [4- (3,4
-Dicarboxyphenoxy) phenyl] propane dianhydride, 2,2-bis (3,4-benzenedicarboxylic acid hydride) perfluoropropane, bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride,
1,3-bis (3,4-dicarboxyphenyl) -1,
1,3,3-tetramethyldisiloxane dianhydride, 1,3-bis [4- (1,2,3,6-tetrahydrophthalic anhydride)]-1,1,3,3-tetramethyldisiloxane These may be used alone or in combination of two or more.

Further, in the general formula (1), each group of R ^{1 to} R ³ and Y is a group derived from the silylated diamine represented by the above general formula (3).

For example, R ^{1 to} R ³ are hydrogen atoms or monovalent hydrocarbon groups having 1 to 10 carbon atoms, and the monovalent hydrocarbon groups include methyl group, ethyl group, propyl group and butyl group. Alkyl groups such as groups, vinyl groups, allyl groups, alkenyl groups such as butenyl groups, phenyl groups, aryl groups such as tolyl groups, and some or all of the hydrogen atoms of these groups are halogen atoms, cyano groups, alkoxy groups A group substituted with, for example, a chloromethyl group, a chloropropyl group, 3,
Examples thereof include a 3,3-trifluoropropyl group, a 2-cyanoethyl group, a methoxy group, an ethoxyethyl group, and among these, those having 6 or less carbon atoms are preferable. In the present invention, typical examples of the silyl group in which R ^{1 to} R ³ are bonded to a silicon atom are as follows, although not limited thereto.

--SiH (CH ₃ ) ₂ , --Si (C
_{H 3) 3, -Si (CH} 3) 2 · C 2 H 5, -Si
_{(CH 3) 2 · CH =} CH 2, -Si (C 2 H 5) 3,
_{-Si (CH 3) 2 · CH} (CH 3) 2, -Si (C
_{H 3) 2 · C (CH} 3) 3, -Si (CH 3) 2 · C
₆ H ₅

The divalent organic group Y is not limited to a particular structure and may have a wide range of structures depending on the structure of the silylated diamine for polymer formation, but it is generally heat resistant. From the standpoint of the like, those having an aromatic ring, for example, an arylene group such as a phenylene group, a group in which two arylene groups are bonded by an alkylene group, an ether group (—O—), etc., and nuclear substitution in these groups The body or the like is suitable. Of course, in addition to these, various organic groups can be used in connection with the structure of the silylated diamine of the general formula (3). For example, it may be a group having a siloxane bond (Si-O-Si) and silethylene bond _{(Si-CH 2 CH 2 -Si} ).

In the present invention, the silylated diamine of the general formula (3) used for producing the polymer having the constitutional unit represented by the general formula (1) is, for example, the following general formula (4): R ³ R ² R ¹ —SiCl (4) In the formula, R ^{1 to} R ³ are as described above, a halogenated silane represented by the following general formula (5): H ₂ N—Y—NH ₂ (5) In the formula, Y is easily obtained by reacting with a diamine represented by

As such a diamine, various diamines can be used without being limited to a specific structure. Specific examples thereof include the following, which may be used alone or in 2 Combinations of more than one species can be used.

P-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,
4'-diaminodiphenyl ether, 2,2'-bis (4-aminophenyl) propane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 1,4-bis (3-aminophenoxy) benzene , 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (p-aminophenylsulfonyl) benzene, 1,4-bis (m-aminophenylsulfonyl) benzene, 1,4-bis (p- Aminophenyl thioether) benzene, 1,4-bis (m-aminophenyl thioether) benzene, 2,2-bis [4- (4-
Aminophenoxy) phenyl] propane, 2,2-bis [3-methyl-4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3-chloro-4- (4-
Aminophenoxy) phenyl] propane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane,
1,1-bis [3-methyl-4- (4-aminophenoxy) phenyl] ethane, 1,1-bis [3-chloro-4
-(4-Aminophenoxy) phenyl] ethane, 1,1
-Bis [3,5-dimethyl-4- (4-aminophenoxy) phenyl] ethane, bis [4- (4-aminophenoxy) phenyl] methane, bis [3-methyl-4- (4
-Aminophenoxy) phenyl] methane, bis [3-chloro-4- (4-aminophenoxy) phenyl] methane, bis [3,5-dimethyl-4- (4-aminophenoxy) phenyl] methane, bis [4- (4-Aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4
Aromatic ring-containing diamines such as -aminophenoxy) phenyl] perfluoropropane.

An aromatic diamine having an amide group as a nuclear substituent represented by the following formula.

[Chemical 4]

Silicone diamine represented by the following formula.

[Chemical 5]

The silylated diamine obtained by the reaction of the diamine and the halogenated silane is converted into the above-mentioned general formula (2)
By reacting with the tetracarboxylic dianhydride of, a polymer comprising the structural unit represented by the general formula (1) is obtained. This reaction (polycondensation reaction) can be easily carried out by mixing and stirring both with an appropriate solvent. In this case, the ratio of the two used may be approximately equimolar, and the reaction temperature may be room temperature. As the solvent, any solvent can be used as long as it is inert to the reaction.

(B) Photosensitive acid generator The photosensitive acid generator of the component (B) includes light such as ultraviolet rays, X-rays,
An acid is generated by irradiation with an active energy ray such as an electron beam, and there are sulfonic acid esters, iodonium salts, sulfonium salts, and the like, and these may be used alone, respectively, Further, two or more kinds can be used in combination.

The sulfonic acid ester generally has the following general formula (6):

[Chemical 6] In the formula, R may be the same or different and each is an alkyl group and an aryl group such as a phenyl group and a diphenyl group, and among them, those shown below are preferably used.

[Chemical 7]

Iodonium salts are generally represented by the following general formula (7):

[Chemical 8] In the formula, R is the same as the above, and X ⁻ is an anion, and among them, those shown below are preferably used.

[Chemical 9]

The sulfonium salt generally has the following general formula (8):

[Chemical 10] In the formula, R and X ⁻ are the same as described above, and among them, the following are preferably used.

[Chemical 11]

The above-mentioned photosensitive acid generator can be blended and used in an arbitrary ratio, but generally, in order to obtain good photosensitivity and storage stability, the polymer of the above (A) is used. 1
It is preferably used in an amount of 0.1 to 30 parts by weight, particularly 0.3 to 10 parts by weight, per 00 parts by weight.

Photosensitive Resin Composition The photosensitive resin composition of the present invention is stored as a solution prepared by dissolving the above-mentioned polymer (A) and photosensitive acid generator (B) in a suitable organic solvent, and Be used.

As the solvent, those which are generally used for the synthesis of the above-mentioned polymer (A) are suitable, for example, N-methyl-2-pyrrolidone, dimethylacetamide, dimethylformamide, Hexamethylphosphoramide, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, butyl cellosolve, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, γ-
Butyrolactone, butyl cellosolve acetate, toluene, xylene and the like are used alone or in combination of two or more kinds, and are set to an appropriate concentration in consideration of workability and the like.

In this solution, known compounding agents such as sensitizers, dyes, plasticizers, thermal reaction inhibitors, antioxidants, antistatic agents, adhesion improvers, etc. may be added as required. It can also be blended.

The solution of the above-mentioned photosensitive resin composition is applied to a substrate such as a silicon wafer, a metal plate, a glass plate or a ceramic substrate by a known method such as spin coating, dipping or printing, and a coating film is formed by drying. Through various steps of exposure, alkali development, and curing, a polyimide protective film having excellent properties such as heat resistance is formed.

The coating film is formed by drying by pre-baking at a temperature of 30 to 180 ° C. for several minutes to several hours using a heating means such as a drier or a hot plate to remove most of the solvent in the coating film. Can be done.

The exposure is carried out by placing a mask on the film formed above and irradiating it with light such as visible light or ultraviolet light for a few seconds to a few minutes. As a result, the photosensitive acid generator releases the acid. Here, a mask aligner, g-line, i-line, and a stepper using an excimer laser as a light source can be used as the visible light or ultraviolet irradiation device depending on the type of the acid generator. is there. A fine pattern can be easily formed by using these devices.

After exposure, post-baking is performed at a temperature of 60 ° C. to 140 ° C. for several seconds to several hours, and the acid generated above converts the silyl ester group in the structural unit of the polymer of the component (A) into a carboxylic acid group. Then, the exposed portion is dissolved and removed with an alkali developing solution to obtain a relief pattern. As the alkaline developer, for example, an aqueous alkali solution such as an aqueous tetramethylammonium hydroxide solution is preferably used.

Since the resin of the remaining relief pattern is in the form of a polyimide precursor, it is heated at a temperature of 200 to 500 ° C., particularly 300 to 400 ° C. for several tens of minutes by a heating means such as a dryer or an electric furnace. By heating for several hours, a patterned positive polyimide film is obtained.

As described above, the photosensitive resin composition of the present invention can be easily patterned, and the resin film formed after curing thereof has excellent heat resistance, mechanical properties and electrical properties. It can be preferably used as a protective film for electronic parts. As the protective film for electronic parts, for example, a junction coat film, a passivation film, a buffer coat film on the surface of a semiconductor element such as a diode, a transistor, an IC, an LSI, an α-ray shielding film for an LSI, an interlayer insulating film for a multilayer wiring, etc. Further, a conformal coat of a printed circuit board, an alignment film of a liquid crystal display element, a protective film in a semiconductor device such as an ion implantation mask, and the like can be used in a wide range.

[0043]

EXAMPLES Synthesis of Polyimide Precursor Polymer Reference Example 1: 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride was placed in a flask equipped with a stirrer, a thermometer and a nitrogen purging device.
16.11 g (0.05 mol) N-methyl-2-pyrrolidone (solvent) (100 g) was charged, and the following silylated diamine: N, N'-bis (t-butyldimethylsilyl) -4,
4'-diaminodiphenyl ether 19.28 g (0.045m
ol) 1,3-bis [3- (N-trimethylsilyl) aminopropyl] -1,1,3,3-tetramethyldisiloxane
A solution of 1.96 g (0.005 mol) dissolved in 49 g of N-methyl-2-pyrrolidone was added dropwise so that the reaction temperature of the system did not exceed 40 ° C.

After completion of dropping, the solution was further stirred for 10 hours to obtain a solution of a polyimide precursor polymer having a viscosity (25 ° C.) of 4,100 cP. As a result of analysis, it was confirmed that this polyimide precursor polymer was represented by the following structural formula.

[Chemical 12]

Reference Example 2: As acid anhydride, 2,2-bis (3,4-benzenedicarboxylic acid hydride) perfluoropropane 19.98 g (0.045 mol) 1,3-bis (3,4-dicarboxyphenyl) -1,
1,3,3-tetramethyldisiloxane dianhydride
2.13 g (0.005 mol) As silylated diamine, N, N'-bis (t-butyldimethylsilyl) -4,
4'-diaminodiphenyl ether 10.71 g (0.025m
ol) N, N′-bis (trimethylsilyl) -4,4′-diaminodiphenyl ether 8.61 g (0.025 mol), γ-butyrolactone 165 g was used as a solvent, and the viscosity (25 ° C. )But
A solution of 4,800 cP of polyimide precursor polymer was obtained.

As a result of analysis, it was confirmed that this polyimide precursor polymer was represented by the following structural formula.

[Chemical 13]

Reference Example 3: 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride as an acid anhydride
12.89 g (0.04 mol) 1,3-bis (3,4-dicarboxyphenyl) -1,
1,3,3-tetramethyldisiloxane dianhydride
4.26 g (0.01 mol) of silylated diamine, N, N'-bis (t-butyldimethylsilyl) -4,
17.06 g of 4'-diaminodiphenylmethane (0.040mo
l) N, N′-bis (trimethylsilyl) -4,4′-diaminodiphenylmethane 3.42 g (0.01 mol) Diethylene glycol dimethyl ether 145 g was used as a solvent, and the viscosity (25 ° C.) was measured by the same operation as in Reference Example 1.
A solution of a polyimide prepolymer having a mass of 3,400 cP was obtained.

As a result of analysis, it was confirmed that this polyimide precursor polymer was represented by the following structural formula.

[Chemical 14]

Examples 1 to 7 To the polyimide precursor polymer solutions obtained in Reference Examples 1 to 3,
The following α, β, γ photosensitive acid generators and the solvent used in the resin solution for preparing the polymer solution were added in the amounts shown in Table 1 to prepare 7 kinds of photosensitive resin compositions. (Example 1
7).

[Chemical 15]

The viscosity (25 ° C.) of these compositions was measured, and the viscosity (25 ° C.) after storage at 5 ° C. for 3 months
Was measured and the storage stability was evaluated by the change in viscosity. The results are shown in Table 1.

Each composition was applied to a silicon wafer by using a spin coater, and then 120 on a hot plate.
The solvent was removed by drying at ℃ for 3 minutes to form a coating film. Then, a photomask having a stripe pattern was brought into close contact with the obtained coating film, and ultraviolet rays from a 500 W xenon-mercury lamp were irradiated for 60 seconds. After irradiation, heat treatment on a hot plate at 110 ° C. for 2 minutes, development with a 2.3% tetramethylammonium hydroxide aqueous solution, and further rinsing with pure water to obtain the line and space pattern shape and The minimum line width (resolution) obtained was measured.
Further, they were cured in a dryer at 200 ° C. for 1 hour and further at 350 ° C. for 0.5 hour, and the adhesion between the cured coating film and the silicon wafer as the substrate was evaluated by a cross-cut test. The results are shown in Table 1. The evaluation of the adhesiveness by the cross-cut test was indicated by the number of the squares remaining when the cured coating film was provided with 100 squares at 1 mm intervals and the adhesive tape was attached and peeled off.

[0052]

[Table 1] The results of Table 1 show that the solutions of the resin compositions obtained in Examples 1 to 7 have good storage stability, good photosensitivity, and excellent adhesiveness to silicon wafers. It is understood that it can be preferably used as a protective film for electronic parts.

[0053]

EFFECT OF THE INVENTION The photosensitive resin composition of the present invention has good sensitivity, does not cause swelling or the like during development, and easily gives a patterned resin film. Furthermore, by heat-curing this patterned film, a polyimide film having particularly excellent heat resistance, electrical properties and mechanical properties can be obtained, and this film can be suitably used as a protective film for electronic parts.

Claims (4)

[Claims] (A) The following general formula (1): In the formula, X is a tetravalent organic group containing an aromatic ring or an aliphatic ring, Y is a divalent organic group, and R ¹ , R ² and R ³ may be the same or different and each is hydrogen. A polymer having a structural unit represented by an atom or an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and (B)
A photosensitive resin composition comprising a photosensitive acid generator. 2. The photosensitive resin composition according to claim 1, wherein the photosensitive acid generator (B) is blended in an amount of 0.1 to 30 parts by weight per 100 parts by weight of the polymer (A). . 3. The photosensitive resin composition according to claim 1, wherein the photosensitive acid generator (B) is at least one selected from a sulfonate ester, an iodonium salt, and a sulfonium salt. 4. A protective film for electronic parts, which is obtained by curing the photosensitive resin composition according to claim 1.