JPH03144648A - Method for producing photosensitive resin composition and resist - Google Patents

Abstract

PURPOSE:To obtain high resistance to oxygen plasma and to allow development with an aq. alkaline soln. by incorporating a specific silicone resin soluble in the aq. alkaline soln., ester of 1, 2-naphthoquinone-(2)-diazide and a surfactant contg. fluorine into this compsn. and specifying the mixing ratios of the surfactant component to the resin component. CONSTITUTION:This compsn. contains the silicone resin (A) which is soluble in the aq. alkaline soln., is expressed by formula I and has 1,000 to 50,000 weight average mol. wt., the ester of the 1, 2-naphthoquinone-(2)-diazide (B) and the surfactant (C) contg. the fluorine. The ratio of the component (C) is specified to 0.001 to 10pts.wt. to 100pts.wt. component (A). The silicone resin (A) which is soluble in the aq. alkaline soln. and is expressed by the formula I is obtd. by using, for example, p-methoxybenzyl trichlorosilane as a starting raw material. The weight average mol. wt. in terms of standard polystyrene thereof is preferably 1,000 to 10,000. The excellent resistance to the oxygen plasma is obtd. in this way and the development with the aq. alkaline soln. is possible.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a photosensitive resin composition and a resist, and more specifically, a photosensitive resin composition using a silicone resin that can be coated with a uniform film thickness on a substrate. The present invention relates to a positive photosensitive resin composition and a method for producing a resist using this composition.

[Conventional technology]

A positive photosensitive resin composition is prepared by coating the composition on a substrate,
A resist pattern obtained by drying, exposing, and developing is widely used because the resist does not swell due to development and can form a fine pattern of 111 m or less.

In recent years, the structure of substrates has become more complex due to higher integration, and various steps have appeared on the substrate. A multilayer resist method has been proposed as a method to obtain a high-precision resist film on a substrate with these steps. and some of them have been put into practical use.

For example, in the three-layer resist method, a first resist film is first formed on a substrate, and then a second resist film is formed as a mask for etching the first layer. Usually, a material such as a silicone film is used for this second layer. This silicone film does not have a pattern forming function, so
Furthermore, a photosensitive resin is applied to the upper layer, and patterned by exposure and development. Next, the second layer of silicon film is etched using the pattern as a mask. Further, using this silicon film as a mask, the first resist film is etched to obtain a predetermined pattern.

Although this three-layer resist method improves processing accuracy, the process of attaching the film before etching the substrate is a long three-step process. A simplified method with a two-step process has been proposed.

Phenol novolac resins, cresol novolac resins, polyhydroxystyrene resins, and the like are used in conventional positive photosensitive resin compositions.

However, since the etching of the first layer using the second layer as a mask is usually performed using oxygen plasma, the conventional positive photosensitive resin composition having low resistance to oxygen plasma is used for etching the second layer. It cannot be used as a membrane.

Silicone resins are known as resins with high resistance to oxygen plasma, but in order to use them as positive photosensitive resins, they are desired to be alkali-soluble.

In addition, in order to cope with the increasing integration and fineness of substrates, a highly accurate film formation technology is required that can reduce the difference in coating film thickness to 100 Å or less when coating resist on the substrate. Become.

As a method for making the coating film thickness uniform, JP-A-58-105
No. 143, JP-A-59-155836, and JP-A-63-34540 disclose surfactants in photosensitive resin compositions containing novolac resins such as phenol novolac resins and cresol novolac resins. A method of adding is disclosed. However, these also do not take into account the oxygen plasma resistance, and cannot be used as a resist for the second layer.

[Problem to be solved by the invention]

An object of the present invention is to solve the problems of the prior art, and to provide a photosensitive resin composition that has high oxygen plasma resistance, can be developed with an alkaline aqueous solution, and has a small difference in coating film thickness. do.

[Means to solve the problem]

The present invention provides an alkaline aqueous solution-soluble silicone resin (A) represented by the formula (I) (in which n represents an integer) and has a weight average molecular weight of i, ooo to 50,000, 1,2-naphthoquinone -(2)
- Photosensitivity containing a diazide ester (B) and a fluorine-containing surfactant (C), and containing the component (C) in an amount of 0.001 to 10 parts by weight based on 100 parts by weight of the component (A). The present invention relates to a resin composition and a method for producing a resist using this photosensitive resin composition.

The alkaline aqueous solution-soluble silicone resin (8) represented by the above-mentioned form (I) used in the present invention is an already known compound, for example, using p-methoxyhensyltrichlorosilane as a starting material in JP-A No. 63-231331. It can be obtained by known methods disclosed in publications and the like.

The weight average molecular weight of the silicone resin (A) in terms of standard polystyrene is 1.
,000 to 50,000, preferably l,
000 to 10,000.

The 1,2-naphthoquinone-(2)-diazide ester (B) used in the present invention is also a known compound and is a photosensitizer for the silicone resin (A), and this compound is
For example, 1,2-naphthoquinone-(2)-diazide-5 (
Alternatively, it can be obtained by dissolving 4-)-sulfonyl chloride and a polyhydroxy compound in a solvent such as dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, water, cellosolve, etc., and synthesizing it in the presence of a basic catalyst to promote the reaction.

As the basic catalyst, normally used are inorganic bases such as sodium carbonate, potassium carbonate, sodium hydroxide, and potassium hydroxide, and organic bases such as triethylamine, triethanolamine, and diethylamine.

1,2-naphthoquinone-(2)-diazide during synthesis
The amount of 5-(or 4-)sulfonyl chloride used is
When the number of hydroxyl groups in 1 mole of the polyhydroxy compound is n, it is preferably 0.3n-n moles. If the amount used is less than 0.3 nmol, the film loss of the resist film during development will be large, which is not preferable.

There is no particular restriction on the synthesis temperature, but from the viewpoint of stability of the main product, reaction rate, etc., 0 to 40°C is preferable. Further, the synthesis reaction is preferably carried out under yellow light or red light.

The ratio of the silicone resin (A) and the photosensitizer (B) to be used is silicone resin (^) / photosensitizer (B) = 90 / from the viewpoint of sensitivity and resolution after development, residual film rate during development, etc. l
The range is preferably 0 to 71/29 (weight ratio).

The fluorine-containing surfactant (C) used in the present invention is a polymer having a fluoroalkyl group in the side chain or main chain, such as a homopolymer such as fluoroalkyl acrylate or fluoroalkyl methacrylate, or a polymer containing these and other polymers. Examples include copolymers with polymers, copolymers of fluorinated ethylene and methyl acrylate, and the like. These can be obtained as commercial products, such as FC-430 and FC-431 manufactured by Sumitomo 3M Co., Ltd., and F-171 and F-173 manufactured by Dainippon Ink and Chemicals Co., Ltd.
etc., a product name manufactured by Asahi Glass Co., Ltd., and AC-710.

This surfactant (C) is silicone resin (A) 100%
0.001 to 10 parts by weight, preferably 0
．． It is used in a range of 0.01 to 5 parts by weight. If the proportion of O or OO used is less than 1 part by weight, there is no effect of adding the surfactant, and if it exceeds 10 parts by weight, air bubbles will not be removed easily when the solution is made.

The positive photosensitive resin composition of the present invention can also be used after being dissolved in a solvent. Examples of the solvent include acetone,
Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, aromatic solvents such as toluene and xylene, cellosolve solvents such as methyl cellosolve, methyl cellosolve acetate, and ethyl cellosolve acetate, ethyl acetate, butyl acetate, isoagol acetate, etc. An ester solvent, an alcohol solution such as methanol, ethanol, propatool, etc. are used. These may be used alone or in combination of two or more.

The photosensitive resin composition of the present invention is applied onto a substrate made of silicon, aluminum, quartz, glass, etc., for example, in a state of being dissolved in a solvent.

A resist is manufactured by applying a solution of the photosensitive resin composition of the present invention onto a substrate, drying it, exposing it to light, and developing it.

The photosensitizer (B) in the photosensitive resin composition of the present invention is photochemically decomposed, becomes soluble in an alkaline aqueous solution after decomposition, and is thereby developed. Photochemical decomposition is carried out by known exposure such as a mercury lamp. As the alkaline aqueous solution, for example, an aqueous solution of 5% by weight or less of sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, choline, etc. is used.

The photosensitive resin composition of the present invention may contain secondary components depending on the purpose. Examples of these are:
For example, thermal polymerization inhibitors for storage stability, antihalation agents to prevent halation from substrates,
Examples include adhesion improvers for improving adhesion to the substrate.

〔Example〕

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

Example 1 Poly(P-hydroxybenzylsilsesquioxane) (
Standard polystyrene equivalent weight average molecular weight 3゜000) 20
parts by weight, 4 parts by weight of 1,2-naphthoquinone-(2)-diazide ester of 2,3.4-trihydroxybenzophenone (degree of esterification of hydroxyl group 75%) and surfactant FC-431 manufactured by Sumitomo 3M Co., Ltd. 0.01 parts by weight,
Dissolved in 76 parts by weight of 2-ethoxyethyl acetate, 0.2μ
A photosensitive solution was obtained by filtration through a Teflon filter with a diameter of m.

Next, add this photosensitive liquid to 3. It was coated on a silicon substrate using OOO rpm and dried on a real plate at 100'C for 60 seconds to form a coating film.

This coating film was exposed to light at 150 mJ/d using an exposure device FPA-1550 manufactured by Canon Co., Ltd., and developed with a 0.6% tetramethylammonium hydroxide aqueous solution to obtain a line width of 111 m.

Further, when the smoothness of the unexposed area was measured using Talystep manufactured by Rank Taylor Hobson, the smoothness was 100 Å or less.

Example 2 Poly(p-hydroxybenzylsilsesquioxane) (
Weight average molecule ff14,000) 30 parts by weight, 2.3,
4.1,2- of 4'-tetrahydroxybenzophenone
6 parts by weight of naphthoquinone-(2)-diazide ester (degree of esterification of hydroxyl group 60%) and 0.03 parts by weight of FC-430 manufactured by Sumitomo 3M were dissolved in 64 parts by weight of 2-ethoxyethyl acetate. A photosensitive solution was obtained in the same manner as in Example 1.

A coating film was formed in the same manner as in Example 1, exposed and developed, and the smoothness of the unexposed area was measured and found to be 100 Å or less.

Comparative Example 1 A coating film was shaped in the same manner as in Example 1, except that the photosensitive solution was not used in Example 1 without using FC-431 manufactured by Sumitomo 3M, and this was exposed, developed, and unexposed. When the smoothness of the part was measured, it was found to be 250 people.

Comparative Example 2 A coating film was shaped in the same manner as in Example 1, except that the photosensitive solution was prepared without using FC-430 manufactured by Sumitomo 3M, and this was exposed, developed, and unexposed. When the smoothness of the part was measured, it was found to be 350 pieces.

〔Effect of the invention〕

According to the photosensitive resin composition of the present invention, it is possible to obtain a resist that has excellent oxygen plasma resistance, can be developed with an alkaline aqueous solution, and has a highly smooth coating film. This photosensitive resin composition can be widely used in fields such as the photographic industry, the printing industry, and the electronic industry.

Claims (1)

[Claims] 1. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, n represents an integer), and has a weight average molecular weight of 1,000 to 50, 000 alkaline aqueous solution soluble silicone resin (A), 1,2-naphthoquinone-(2)
- Photosensitivity containing a diazide ester (B) and a fluorine-containing surfactant (C), and containing the component (C) in an amount of 0.001 to 10 parts by weight based on 100 parts by weight of the component (A). Resin composition. 2. A method for producing a resist, which comprises applying and drying a solution of the photosensitive resin composition according to claim 1 onto a substrate, followed by exposure and development.