JPS59212832A - Photosensitive heat resistant material - Google Patents

Abstract

PURPOSE:To obtain a resist microworkable with direct light and superior in heat resistance by using a compd. obtained by additionally reacting an unsatd. aziridine compd. with carboxylic groups linked to the side chains of polyimide acid, and a bisazide compd. CONSTITUTION:An aziridine compd. represented by the general formula shown here (R3 is an org. group having at least one unsatd. bond) is reacted in an amt. of 0.2-2.0 equivs. at <=60 deg.C, preferably, at 20 deg.C- room temp. for 2-6hr with carboxylic acid groups linked to the side chains of a polyamide acid produced by reacting diamine with tetracarboxylic dianhydride in an org. solvent to obtain a polyimide precursor. A support is coated with a mixture of said precursor and a bisazide compd. as a photo-crosslinking agent, such as 2,6-di(p-azidobenzal)-4-methylcyclohexanone, precured, exposed and developed, and then, heat treated at 200-400 deg.C.

Description

[Detailed description of the invention] The present invention relates to a novel photosensitive heat-resistant material.

Conventionally, inorganic materials such as silicon oxide have been widely used in the semiconductor industry as insulating layers and passivation layers of solid-state devices.

On the other hand, organic materials have properties such as low stress, excellent smoothness, and high purity compared to inorganic materials, and in recent years, technology for using them as insulating layers and passivation layers has been developed, and some semiconductors It has been put into practical use in devices.

When an organic material is used for the above-mentioned purpose, the material is required to have thermal stability because it undergoes work steps such as die bonding, and it is necessary to use a heat-resistant organic material. Therefore, polyimides with excellent heat resistance are generally being widely studied.

When polyimide is used as an insulating layer or passivation layer of a solid-state device, photoresist is generally used in the process of performing microfabrication, such as for conducting parts between upper and lower conductor layers and through-holes for connection to external lead wires. A chemical etching process is carried out.

For example, polyamic acid, which is a polyimide precursor, is coated on a substrate, heat-treated to convert it into polyimide, a photoresist relief pattern is formed on the polyimide, and the polyimide film is selectively chemically etched using a hydrazine-based etching agent. A relief pattern is formed on the polyimide.

However, in the patterning of polyimide in the above process,
Processes such as photoresist coating and peeling are required, making the entire process extremely complicated. Therefore, in order to simplify the microfabrication process, it has been desired to develop a heat-resistant material that can be microfabricated using direct light. As one of the above objects, a photosensitive heat-resistant material comprising a polyamic acid and a dichloride salt was proposed (Japanese Patent Publication No. 17374/1983).

According to this document, it is possible to form a polyimide relief pattern by coating the material on a substrate, drying it, exposing it to light using a normal optical method, developing it, and then performing heat treatment. However, this material has poor storage stability because it involves a dark reaction, and must be used immediately after being prepared as a photosensitive heat-resistant material by mixing dichromate.
Further, since the dichromate remains in the cured product, there is a drawback that the cured product has poor reliability as an insulating film.

Furthermore, JP-A-49-115541 describes, for example, the general formula: (wherein, R is OH2=0HOOOOH20H2% G
A photosensitive heat-resistant material obtained by reacting H2=O(OH3)OOOOOH20H2-1 has been proposed. However, the process for synthesizing the pyromellitic acid derivative is complicated, and its purification is also difficult, so that the resulting photosensitive heat-resistant material is expensive.

Furthermore, JP-A-55-45746 describes that a photosensitive heat-resistant material can be obtained by reacting monopolyamic acid with a monoepoxide having a photosensitive group such as methacrylglycidyl.

However, the reaction between epoxide and carboxylic acid is very complicated, requiring a reaction accelerator, and furthermore, there are drawbacks such as extremely poor storage stability after the reaction.

The present inventors have conducted extensive research aimed at overcoming the above-mentioned drawbacks and providing a photosensitive heat-resistant material that can be microfabricated and in which a relief pattern is formed by ordinary exposure means.As a result, (IL) General formula (1) : %Formula % (1) (In the formula, R1 represents a divalent organic group) A diamine represented by the general formula (2): %Formula% (In the formula, R2 contains at least 2 carbon atoms) do 4
A polyamic acid obtained by reacting a tetracarboxylic dianhydride represented by the general formula (3): A polyimide precursor obtained by reacting an azinodine compound represented by the monovalent organic group (indicating the monovalent organic group contained) and (1)) the general formula (
4): N3 R4N3 (4) (wherein, R
4 indicates a divalent organic group) is useful for insulating layers and passivation layers of solid-state devices as a material that can be microfabricated by direct light. JH45 is a photosensitive heat-resistant material characterized by adding an unsaturated aziridine compound to the carboxyl group of the side chain in the polyamic acid produced by the reaction with JH45, and then adding a bisazide compound as a photocrosslinking component. .

As the diamine represented by the general formula (1), even -'
-I Ha 4,4-diaminodiphenyl ether, 4,4-diaminodiphenylmethane, 4,4-diaminodiphenylsulfide, 4t4-diaminodiphenylsulfone,
3.3-diaminodiphenyl sulfide, 3,3-diaminobenzophenone, 4.4-diaminobenzophenone, benzidine, o-tolidine, p-phenylenediamine, m-phenylenediamine, 1,5-diaminonaphthalene, 4,4-diamino Cyclohexylmethane, xylylene diamine, diaminophenyl indene, hexamethylene diamine, 1,3-di(p-aminophenyl)tetramethyldisiloxane, bis(r-aminopropyl)tetramethyldisiloxane, 4,4-diaminostilbene, etc. One type or a mixture of two or more thereof can be used in the present invention.

Examples of the tetracarboxylic dianhydride represented by the general formula (2) include pyromellitic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propanedic anhydride, and bis(3,4-dicarboxyphenyl)propanedic anhydride. dicarboxyphenyl)ether dianhydride, 3.3', 4.4'-benzophenonetetracarboxylic dianhydride"+'+4.4'-hyphenyltetracarboxylic dianhydride, 1.2.5. 6-naphthalenetetracarboxylic dianhydride, 2,2-bis(dicarboxyphenyl)hexafluoropropanedioic anhydride,
1.2.3.4-butanetetracarboxylic dianhydride, 1
, 2.3. , 4-cyclopenkunetetracarboxylic dianhydride, 5-(2,5-dioxotetrahydro 7su#)
Examples include -5-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, and one or a mixture of two or more thereof can be used in the present invention.

In the present invention, it is preferable to react the diamine and the tetracarboxylic dianhydride in equimolar amounts to obtain the polyamic acid. -Dimethylformamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, hexamethylphosphoamide, etc. are preferably used. Further, the reaction is carried out at a temperature of 80°a or less, preferably 20°a.
It is preferable that the temperature is maintained at around 0.000 to room temperature for 2 to 10 hours.

Examples of the aziridine compound represented by the general formula (3) include 1 0 (in the formula, n represents O or 1), and one or a mixture of two or more thereof can be used in the present invention. It will be done.

The reaction between the polyamic acid and the aziridine compound is desirably carried out at a temperature of 60°C or less, preferably at a temperature of 2080°C to room temperature for 2 to 6 hours.

The reaction proceeds rapidly and does not particularly require reaction accelerators such as salts, solubilizers, and bases, so the photosensitive heat-resistant material of the present invention has extremely excellent storage stability.

In the present invention, the aziridine compound is preferably reacted with the side chain carboxyl group in the polyamic acid in an amount of 0.2 to 2.0 equivalents, preferably 0.5 to 1.0 equivalents. If the amount is less than 0.2 equivalent, the crosslinking reaction upon exposure will not occur sufficiently, resulting in poor relief pattern forming ability. If the amount exceeds 2.0 equivalents, the heat treatment in the final step will not be carried out well, and the cured product will have poor thermal stability.

In addition, it is preferable that the bisazide compound, which is a photosensitive crosslinking agent, be added in an amount of 1 to 50% by weight based on the polyimide precursor.If it is less than 1% by weight, no significant crosslinking effect will be exhibited, and if it exceeds 50% by weight, the cured product will be poor thermal stability.

Examples of the bisazide compound include 2,6-di0-acidobenzal)-4-methylcyclohexanone, 2.6
-di(p-acidobenzal)cyclohexanone, 4,4
-Diazidobenzanacetone, 4.4'-Diazidostilbene, 4.4/-Diazidochalcone, 4.4'-Diazidobenzophenone, 2,8-Diazidoacridine, 4
．． Examples include 4-diazidiphenylmethane, and one or a mixture of two or more thereof can be used in the present invention.

The photosensitive heat-resistant material of the present invention can obtain a clear relief pattern by exposing it as it is, but by adding o, o1 to 1o wt% of a photosensitizer to the resin content, a remarkable photosensitization effect can be obtained. represents.

Such photosensitizers include, for example, cyanoacridine, 2-chloro-1,8-phthaloylnaphthalene, anthrathrone, 2-bromo-1,2-penzoanthrachy/
2-chloro-1,2-benzanthraquinone, 1,
2-benzanthraquinone, 1,8-dinitropyrene,
Examples include 1-nitropyrene, 5-nitroacenaphthene, Michler's ketone, etc., and one or a mixture of two or more thereof may be used, but the present invention is not limited thereto.

The photosensitive heat-resistant material of the present invention is spin-coated onto a glass plate or silicon wafer, pre-cured at a temperature of 50 to 9000, and then irradiated with light or radiation through a mask having a predetermined pattern. By developing with a solvent such as 2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylpolamide, etc., the unexposed areas are washed away and a sharp relief pattern on the end surface is changed. Further, by performing a heat treatment at 200 to 400 DEG C., a cured product having excellent heat resistance, chemical resistance and electrical properties and a good relief pattern can be obtained.

The photosensitive heat-resistant material of the present invention can be stably stored at room temperature and protected from light for several months.

In addition, the photosensitive heat-resistant material of the present invention is not only useful as a material for insulating layers and passivation layers of solid-state devices such as semiconductors, or as a material for insulating films of magnetic heads, but also as a solder resist for printed circuits and as a highly heat-resistant material. It can also be applied to materials such as photoresists, step-off materials, etc.

The present invention will be described in more detail below based on Examples, but the present invention is not limited to these Examples.

Example 1 A 100 m four-loaf flask equipped with a thermometer, a stirrer, a nitrogen introduction tube, and a calcium chloride tube was charged with a 4 μm tube and thoroughly mixed. Add 3.229 (0.01 mol) of 3.3,4.4-benzophenonetetracarboxylic dianhydride to the solution.
After adding at once, the polyamic acid was heated to 711C by stirring at 25°C for 4 hours.

2(aziridinyl)ethyl methacrylate) (OH2= O(OH3)) is added to the polyamic acid solution thus obtained.
- Reacted for 4 hours.

After reaction, 2.6-bis(p-acidobenzal)-4-methylcyclohexanone 0.749 (0,002 mol)
The photosensitive heat-resistant material of the present invention was obtained by adding the entire amount.

The material thus obtained was applied onto a glass plate and heated to 60°C.
After drying for 15 minutes at
0cm). A good relief pattern was then obtained by immersing it in NMP for 60 to 120 seconds.

The relief pattern was heated at 100°0 for 10 minutes at 200°C.
When heat treatment was performed at 350°C for 15 minutes and then at 350°C for 30 minutes, the relief pattern did not become blurred.

Examples 2 to 10 The same operations as in Example 1 were carried out according to the blending amounts of each component shown in Table 1 to obtain photosensitive heat-resistant materials of the present invention.

The obtained material is spun onto a silicon wafer)
After drying at 6000 for 30 minutes, Nino ≦ rotation (i'
Ultraviolet P:JI exposure was performed in the same manner as in 111, and NMP
When developed with , good relief patterns were obtained in all cases.

After development, heat treatment was performed at 100° 0 for 15 minutes, at 20,000° for 15 minutes, and then at 650° 0 for 60 minutes in a nitrogen-containing atmosphere, and no disturbance occurred in the relief patterns of all cured products.

In addition, thermogravimetric loss measurements of the cured product obtained in Example 1 and the (1jjj compound) (under nitrogen atmosphere, heating rate 5
0/min), the temperature of the cured product obtained in Example 9 was 390°C, and that of the cured product obtained in Example 10 was 370°C.
Although decomposition started at 0°O, the cured products obtained in Examples 1 to 8 showed no decrease in weight and bis at temperatures below 400°O and had heat resistance.

The photosensitive seals obtained in all of the examples showed stable buttering properties and extremely excellent storage stability when left at room temperature and shielded from light for 6 months. .

Procedural amendment (voluntary) 1. Description of the case: Japanese Patent Application No. 58-87878 2, Title of the invention: Photosensitive heat-resistant material 3, Representative Hitoshi Katayama of the person making the amendment: 5, Subject of amendment (1) “Detailed description of the invention” in the specification Column 6, Contents of amendment (1) "Dichromic acid" on page 4, line 8 of the specification is corrected to "dichromic acid."

that's all

Claims (3)

[Claims] (1) (a) General formula (1): %Formula% (1) (Formula N R1 indicates a divalent organic group) and general formula (2): %Formula% (Formula 1'' =Rz represents a tetravalent organic group containing at least 2 carbon atoms) is reacted with a tetracarboxylic dianhydride represented by formula (3) in an organic solvent. (In the formula, R3 represents a monovalent organic group containing at least one unsaturated bond) A polyimide precursor obtained by reacting an aziridine compound represented by (b) the general formula (4
): % A photosensitive heat-resistant material mixed with a bisazide compound represented by the formula % (4) (in the formula, R4 represents a divalent organic group). (2) The photosensitive heat-resistant material according to claim g5 (1), wherein the aziridine compound is reacted with the side chain carboxyl group in the polyamic acid within a range of 0.2 to 2.0 equivalents. (3) Using the above bisazide compound as a polyimide precursor