JPS61153632A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To increase the sensitivity of the titled composition against the rays of light having <=400nm a wavelength, and to form a fine pattern in a short period by incorporating to the titled composition, an ester obtd. by the esterification of all or a part of hydroxy groups contd. in the resin having phenolic hydroxy groups and fluorene-9-carboxylic acid or xanthene-9-carboxylic acid. CONSTITUTION:The resin having the phenolic hydroxy group is not specially limited when it comprises the phenolic hydroxy group in a molecular. Said resin comprises a novolak resin obtd. by condensating at least one of group composed of for example, phenol, o-chlorophenol, m-creasol, bisphenol A, and 4-chloro-3-creasol with formalin. Or the resin obtd. by condensating said phenols with acetoaldehyde or benzaldehyde instead of formalin and a p-vinyl phenol polymer are used. The esterified resin is prepared by dissolving the resin having a phenolic hydroxyl group to a solvent such as tetrahydrofuran followed by mixing fluorene-9-carboxylic acid and a base. The titled composition is prepared by mixing said resin to a desired compd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a novel photosensitive composition, and more particularly,
The present invention relates to a photosensitive composition that has high sensitivity to light of 400 nm or less and is capable of forming fine patterns in a short time.

[Technical background of the invention and its problems] Photosensitive resins are widely used in many flat plate process fields including semiconductor manufacturing, but they are widely used in many electronic devices! ! In order to achieve high-density integration as devices become more sophisticated and become more sophisticated, there is a strong demand for pattern miniaturization, and for this miniaturization, there is also an increasing demand for dry etching processes.

In general, there is a close relationship between the wavelength of irradiation light and the resolution; the shorter the wavelength, the better the resolution, and the quality of dry etching resistance is determined by the presence or absence of an aromatic ring in the photosensitive resin used.

Conventionally, polymethyl methacrylate (PMMA) and polymethyl isopropenyl ketone (PMIPK) have been used as photosensitive resins for short wavelengths (300 nm or less). However, resists using these photosensitive resins had poor dry etching resistance.

[Object of the invention] The object of the present invention is to eliminate the above-mentioned drawbacks.
The object of the present invention is to provide a photosensitive composition that has high sensitivity to light and can form fine patterns in a short time.

[Summary of the invention] The present invention provides a resin having a phenolic hydroxyl group,
It consists of an esterified resin in which some or all of the hydroxyl groups are esters of fluocine-8-carboxylic acid or xanthene-9-carboxylic acid.Here, the resin having phenolic hydroxyl groups has phenolic hydroxyl groups in one molecule. Any substance having a phenolic hydroxyl group may be used, such as phenol, 0-chlorophenol, chlorophenol, p-chlorophenol, and ■-cresol.

p-cresol, bisphenol A and 4-chloro-3
- at least one selected from the group consisting of cresol, etc.
Novolak resin obtained by condensing seeds with formalin, or resin condensed using aldehydes such as acetaldehyde and benzaldehyde instead of formalin; p-vinylphenol polymer; p-vinylphenol and methacrylic acid Copolymer with methyl; p
- copolymers of vinylphenol and methacrylic acid; copolymers of p-impropenylphenol and styrene; and terpolymers of p-impropenylphenol, 7-crylonitrile, and styrene.

The esterification rate of the esterified resin used in the composition of the present invention is usually 5 to 80%, preferably 10 to 50%, based on the hydroxyl groups of the resin having phenolic hydroxyl groups.
It is. If this esterification rate is less than 5%, a good image cannot be formed because the solubility difference between the exposed and unexposed areas is small, and if it exceeds 80%, a lot of energy is required for exposure. Therefore, it cannot be said to be practical.

The photosensitive composition of the present invention has high sensitivity to light of 400 ns or less and can form a fine pattern in a short time, so it can be used as a good photosensitive material. .

When used as a photosensitive material, the esterified resin is simply heated and applied to a substrate in a molten state. In order to improve the smoothness of the painted surface, it is preferable to use a solution dissolved in an organic solvent. Examples of the organic solvent include toluene, xylene, and O-dichlorobenzene.

Chloroform, cyclopentanone, cyclohexanone,
Cellosolve acetate and methyl ethyl ketone are used. Furthermore, considering characteristics such as changes in pattern dimensions due to reflection of light from the substrate and smoothness of the coated surface, light absorbers such as acetophenone and benzophenone, and surfactants such as ethylene oxide-propylene oxide copolymer It can also be used in the form of a composition.

An example of the use of the photosensitive composition of the present invention will be shown.

A composition consisting of an esterified resin and an organic solvent is applied onto a support (for example, a silicon wafer) by spinning or the like. The coated wafer is then heated to 70-100°C.
After drying for 30 seconds to 30 minutes, the layer is exposed to ultraviolet light in an appropriate wavelength range through a mask, and developed with an appropriate basic solution to obtain a patterned layer.

Next, a method for producing the photosensitive composition of the present invention will be described. First, a resin having a phenolic hydroxyl group is dissolved in a solvent such as tetrahydrofuran, and fluorene-9-
The acid chloride of carboxylic acid or xanthene-9-carboxylic acid is added, a base such as triethylamine is added, the reaction is carried out for several hours at room temperature, the solvent is distilled off, and the reaction product is washed with water. The salt is removed to obtain an esterified resin. Then, the obtained engineered resin is combined with a desired compound to obtain the photosensitive composition of the present invention.

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

[Example of the invention] 1 Arashi 1" p-r: 100 g of novolak resin obtained by condensing phenol and trioxane with para-toluenesulfonic acid
was dissolved in 500 g of ethyl cellosolve acetate, 20 g of fluorene-8-carboxylic acid chloride was added, and 50 g of triethylamine was added. Stirring was performed at room temperature for 5 hours, the generated salt was filtered, and the solution was concentrated to obtain an esterified product as a solid. This product was washed with water, further dissolved in acetone, and gradually added to water to obtain 105 g of purified esterified resin.

Ester absorption was confirmed from the infrared spectrum.

Nen JLf2Lλ p-vinylphenol (molecular weight approximately 8000, Maruzen Sekiyu Re5in M) 100g to 1% tetrahydrofuran
Add 25 g of xanthene-9-carboxylic acid chloride, add 80 g of triethylamine, stir at room temperature for 14 hours, remove the salt, evaporate the solvent under reduced pressure, dissolve in acetone, and reprecipitate from water. As a result, 90 g of esterified resin was obtained.

Support 1 The photosensitive composition of the present invention obtained by dissolving 4 g of the esterified resin obtained in Synthesis Example 1 in 12 g of cyclohexanone was applied onto a silicon wafer substrate using a spinner, and then heated at 80° C. for 30 minutes. After drying, a photoresist film having a film thickness of 1.2 gm was formed on the substrate. Then, the substrate having the photoresist film was exposed for 80 seconds to SOOW xenon-mercury or the like through a quartz substrate masked with chromium. At that time, a cold mirror that transmits light with a wavelength longer than 300 nm was interposed between the light source and the mask, so that only light with a wavelength of 200 to 300 m+1 was exposed. Next, the exposed substrate was treated with two volumes of tetramethylammonium hydroxide (T) at 25°C.
MAH) was immersed in an aqueous solution and developed. Then, when it was washed with water, a pattern consisting of lines and spaces similar to IIL was formed. Subsequently, the etching speed was measured using various dry etching apparatuses, and it was found that the etching speed was approximately the same as that of a conventional positive type resist for long wavelengths.

[Effects of the Invention] As detailed above, the photosensitive composition of the present invention has a
It has a high sensitivity to light of nm or less and can form fine patterns in a short time, and its industrial value is extremely large.

Claims (1)

[Claims] 1. A photosensitive composition comprising an esterified resin having a phenolic hydroxyl group, in which some or all of the hydroxyl groups are esters of fluorene-9-carboxylic acid or xanthene-9-carboxylic acid.