JPS61239245A - Photoresist material - Google Patents

Abstract

PURPOSE:To improve adhesion between a photoresist material and a substrate and to enhance corrosion resistance of the hardened film by using a polymer having a mol.wt. of >=5,000 as a photosensitive component having partial structural units represented by specified general formula I. CONSTITUTION:The photoresist material is formed by polymerizing or co polymerizing a compd. having both of hydroxyl and azidobenzoyl groups represented by formula I where R1 being H, methyl, or ethyl and R2 being 1-3C alkyl or such alkoxy, to form a polymer having a mol.wt. of >=5,000 and partial structural units represented by formula II as a photosensitive compo nent. It is preferred to use these partial structure in an amt. of >=10wt% of the polymer.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a photoresist material, and more particularly to a photoresist material mainly composed of a high molecular weight polymer having an azidobenzoyloxy group in its side chain. It is something.

[Conventional technology]

As is well known in the industry, photoresists are used for integrated circuits,
It is an indispensable material for various types of metal precision processing, including the production of printed wiring boards, metal letterpress printing, halftone dot gravure, etc. Various types of 7-photoresist are used depending on these various uses, but the generally required performance is high sensitivity to the light source used, good resolution, and good connection with the substrate. The adhesive properties of the cured film are strong, the cured film has high mechanical resistance and 2 ting resistance, the storage stability is good, and the photosensitive film has high thermal stability.

Conventionally used negative type 7-otoresists can be roughly divided into four types as follows.

(I) Dichromates added as a photocrosslinking agent to natural polymers such as glue, casein, and shellac, or synthetic polymers such as polyvinyl alcohol.

(2) Photodimerizable cinnamic acid is esterified into poly and nyl alcohol and attached to the side chain (US Patent No. 261
No. 0120).

(3) Natural or synthetic rubber is cyclized and an aromatic bisazide compound is added thereto as a photocrosslinking agent (US Pat. No. 2,852,379).

(4) A photopolymerization initiator added to a prepolymer having a polymerizable unsaturated group (Japanese Patent Publication No. 45-25231)
.

[Problem that the invention seeks to solve]

Since rubber itself has no photosensitivity, a low-molecular-weight bisazide compound is used as a photocrosslinking agent, so at present there was a large drop in sensitivity due to atmospheric oxygen, and it was necessary to remove oxygen.

[Means to solve the problem]

As a result of intensive studies, the present inventors found that it has high sensitivity, good adhesion to various metal, glass, silicone, etc. substrates, provides sharp images, has good corrosion resistance of the cured film, and has excellent thermal stability. A high quality photoresist material has been obtained.

That is, 1 the present invention provides 1+CU, -C represented by the general formula (I)
It is a photoresist material whose photosensitive component is a high molecular weight polymer having a molecular weight of 5,000 or more and containing a +- partial structure as a structural unit.

The high molecular weight polymer used in the present invention can be obtained by polymerizing or copolymerizing a compound represented by the general formula (I[) having both a hydroxyl group and an azidobenzoyl group.

CH2=C H acrylate or this methacrylate, 2-human As the copolymerization component of the high molecular weight polymer used in the present invention, almost all ordinary polymerizable unsaturated compounds can be used, but among them (meth)acrylic acid .

Maleic acid, fumaric acid, and their esters.

Styrene, acrylonitrile, vinyl acetate, acrylamide, vinyl chloride, N-vinylpyrrolidone.

N-vinylcarbazole and the like are preferred.

In addition, the high molecular weight polymer used in the present invention can be obtained by copolymerizing the above-mentioned copolymerization components in advance, and then adding para-azidobenzoic acid or the like to the side chain thereof to obtain a partial structure represented by the photosensitive general formula (I). The content is preferably 10% by weight or more relative to the high molecular weight polymer, and if this amount is less than 10% by weight, photosensitivity decreases.

Further, the molecular weight of the high molecular weight polymer is preferably 5000 or more,
If the amount is less than this, the photosensitivity and processing resistance of the cured film will be reduced, resulting in a photosensitive solution for photoresists. However, in some cases, a suitable amount of a compound known as a triplet sensitizer may be added for use as a photosensitive solution. Examples of such sensitizers include 5-nitroacenaphthene, 2-nitrofluorene, 1-nitropyrene, and cyanoacridine.

The photoresist prepared in this way.

Coated on any commonly used support.

Examples of the support include copper, zinc, iron, aluminum, nickel, machinicum, crow, silicon, etc. Various coating methods such as rotation, dipping, and spraying can be used.

The coated and dried photoresist layer is selectively exposed to light and then developed with a common solvent to remove the unexposed areas from the support and form a predetermined image.

〔Effect of the invention〕

7. The photoresist material of the present invention contains a special functional group in the polymer, so the polymer itself has high photosensitivity. It also has good thermal stability and excellent storage stability. Furthermore, the image obtained after JLL is clear, and the cured film has excellent etching resistance, and has extremely high resistance to corrosive liquids for metals, glass, silicon, and the like.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Production Examples, Examples, and Comparative Examples.

In the examples, parts are parts by weight, and molecular weights are weight average molecular weights determined by GPC method.

Production example 1゜30 parts of ethyl acrylate, 2 parts of benzyl methacrylate
5 parts of tert-butylperoxy-2-ethylhexanoate and 300 parts of methyl ethyl ketone were charged, and after leaving at room temperature for 30 minutes while blowing nitrogen, the temperature was raised to 80°C while stirring, and for 5 hours. A reaction was carried out. After the reaction was completed, the contents were poured into a large amount of methanol to precipitate the reaction product, filtered and dried, and then purified by reprecipitation three times using benzene and methanol.

The molecular weight of the obtained polymer (2) was 75,000. Production Example 2: 60 parts of acrylate, 20 parts of vinyl acetate, 20 parts of dimethyl maleate, 1.5 parts of benzoyl peroxide, 12 parts of xylene.
The polymerization reaction was carried out at 90''C for 6 hours while stirring and blowing nitrogen into the solution.

The molecular weight of the obtained polymer was 60. 6 songs with OOO.

Production Example 3 70 parts of tacrylate, 20 parts of styrene, 10 parts of methyl methacrylate, 1 part of azobisisobutyronitrile, 200 parts of methyl isobutyl ketone, and 100 parts of toluene were charged and polymerized in the same manner as in Production Example 1, and purified. I did this.

The molecular weight of the obtained polymer 0 was 9Q, OOO.

Production Example 4 Glycidyl methacrylate 50 in a flask with a stirrer
parts, 30 parts of isobutyl methacrylate.

20 parts of methyl acrylate, 2 parts of benzoyl peroxide, and 200 parts of methyl ethyl ketone were charged, and a polymerization reaction was carried out at 80°C for 5 hours while blowing nitrogen. After completion of the reaction, 5B parts of bara-azidobenzoic acid.

2 parts.

- A solution of 0.1 part of hydroquinone methyl ether and 100 parts of methyl ethyl ketone was added to the flask and heated to 80"C.
The reaction was carried out with K for 5 hours. After the reaction is complete.

Purification was performed in the same manner as in Production Example 1.

The molecular weight of the obtained polymer (1) was 75,000.

Examples 1-6 As shown in Table 1, the polymers (2
) to ■) were dissolved using cyclohexanone to give a weight range of 10% to obtain a photosensitive solution. At this time, as shown in Table 1, 5-nitroacenaphthene (NA) was used as a sensitizer.
A photosensitive solution was also prepared in which 2-nitrofluorene (NF) was added in an amount of 10% by weight based on the polymer.

These photosensitive liquids were spin-coated onto a copper substrate to a thickness of 2P, and after drying, a negative mask pattern, Kodakste, and Butalt No.
After exposure for 10 seconds from a distance of 5α, development was performed with trichlorethylene. After being left at 120°C for 10 minutes, etching was performed using a 422 Baume ferric chloride solution. The storage stability of the photosensitive solution was determined by a storage test at 25°C for 6 months, the thermal stability of the photosensitive layer was determined by a heating test at 80°C for 30 minutes, and the acid resistance was determined by the change in the cured film due to the above etching solution. observed. The above results are shown in Table 1.

Comparative Examples 1 to 3 As shown in Table 1, the photosensitive polymer had a polymerization degree of 50.
0 polyvinyl cinnamate ■, E and sensitizer.

Tests were carried out in the same manner as in the examples using each of the polymers (1) having a molecular weight of 3,500 synthesized according to Production Example 1. The results are shown in Table 1.

1) Sensitivity indicates the number of steps on the step tablet, and the larger the number, the higher the sensitivity.

2) O: No change at all X: Swelling or partial peeling 3) O: No change in performance As can be seen, the samples of Examples have significantly higher sensitivity than those of Comparative Examples), and also have good acid resistance, thermal stability, and storage stability.

Claims (1)

[Claims] There are mathematical formulas, chemical formulas, tables, etc. represented by the general formula (I).
) [In the formula, R_1 represents a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and R_2 represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. ] A photoresist material whose photosensitive component is a high molecular weight polymer having a molecular weight of 5,000 or more and containing a partial structure as a structural unit.