JPH02264256A - Radiation sensitive composition and pattern forming method using the same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radiation-sensitive composition suitable for forming fine patterns and a pattern forming method using the same.

[Conventional technology]

Photoresists made of alkali-soluble phenol resin and photosensitive def-1-quinonediazide are often used in the production of highly integrated semiconductor integrated circuits. After coating the photoresist on the substrate and baking it, pattern exposure is performed using a reduction projection exposure device, and a pattern is formed by development with an alkaline aqueous solution.

This type of pattern forming method is known, for example, from Japanese Patent Laid-Open No. 61-86
749.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, the formation of a fine pattern with high resolution is
However, there is a problem in that an alkaline substance that is toxic to the human body and has poor storage stability is used as an image solution for the resist.

An object of the present invention is to provide a new radiation-sensitive composition and pattern forming method that uses an acidic aqueous solution that has almost no effect on the human body and has good storage stability as a resist image solution.

[Means for solving problem 'a]

In order to achieve the above objective, polyvinylpyridine, which is soluble in acidic aqueous solution, was used instead of alkali-soluble phenolic resin, which is the matrix polymer conventionally used in resists, and aromatic A composition using a group azide compound is preferred. Further, pattern formation is performed by using an acidic aqueous solution as a resist developer.

The polyvinylpyridine used in the present invention is basic, has 141 molecules, and is soluble in dilute acidic aqueous solution. Moreover, when irradiated with radiation in the presence of an aromatic azide compound, a crosslinking reaction occurs and the resist becomes insoluble in an acidic aqueous solution, functioning as a so-called negative resist. Polyvinylpyridine currently includes poly(4-vinylpyridine) and poly(2-vinylpyridine).
-vinylpyridine), both of which function as negative resists in the coexistence of an azide compound.

In addition, poly(halogenated-1-alkylpyridine), which is a derivative of polyvinylpyridine, becomes a negative resist when irradiated with irradiation in the coexistence with an aromatic azide compound6. Therefore, dry etching resistance is required. This tri-etching resistance is 41? It is important that the molecule rp has an aromatic ring. Polyvinylpyridine has one aromatic ring within the unit molecule and has extremely high etching resistance.

There are no particular restrictions on the aromatic azide compound that makes polyvinylpyridine acid-insoluble through photo-crosslinking, but when using light as radiation to form fine patterns, the shorter the wavelength of the light used, the higher the resolution. It is known that pattern formation is possible. Therefore, as the azide compound used in the present invention, those represented by the following general formula having an absorption maximum in the deep ultraviolet region of 200 to 320 nm are particularly suitable.

Here, A is o, S, CH2, CH, CH,.

An element or substituent that is nonconjugated with two benzene rings, such as SO2 or 82, X is H or Nx, Z is a substituent that is Nδ when X is H, and H or CQ when X is N8 Represents each element.

In order to have an absorption maximum in the deep ultraviolet region with a wavelength of 200 to 320 nm and not have a large absorption above 320 nm, in the structure shown in formula (1), A must be an element or substituent that is not conjugated with the benzene ring. is necessary. Also,
Although there are azide compounds with only one benzene ring that satisfy the above conditions, they have drawbacks such as their low boiling point, which causes them to volatilize during the pre-beta process, and are not expressed by the above formula (1). Practically preferred is an azide compound having the following composition.

Also, among the azide compounds having the composition represented by the above formula (1), 4,4'-diazido diphenyl sulfide, 4,4'-diazido diphenyl sulfone, 3,3'
-diazido diphenyl sulfone, 4,4'-diazido diphenylmethane, 3,3'-dichloro-4,4'-diazido diphenylmethane, 4,4'-diazido diphenyl ether, 4゜4'-diazido diphenyl disulfide and 4°4I-Diazidobibenzyl is particularly preferred since it is efficiently decomposed by radiation irradiation.

[Effect]

A matrix polymer used in a resist that can be developed in an acidic aqueous solution must be soluble in the acidic aqueous solution. The polyvinylpyridine and vinylpyridine copolymer used in the present invention can be prepared using dilute acidic aqueous solutions such as acetic acid, citric acid, oxalic acid,
Tartaric acid, succinic acid.

Since it has the property of being soluble in dilute aqueous solutions of organic acids such as malonic acid and inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid, it is suitable as a matrix polymer for resists that can be developed in acidic aqueous solutions. Moreover, if the azide compound is irradiated with radiation in the presence of the azide compound, it will become insoluble in an acidic aqueous solution, so if it is developed with an acidic aqueous solution after pattern exposure with radiation, a negative resist pattern will be formed.

The azide compound that induces the insolubilization of polyvinylpyridine must be efficiently decomposed by radiation irradiation and must be able to insolubilize the polyvinylpyridine with high sensitivity.The azide compound used in the present invention has high sensitivity to radiation, so it cannot be used in the same way as conventional resists. It is possible to form a fine resist pattern with a certain amount of irradiation.

〔Example〕

Example 1 20 g of poly(2-vinylpyridine) and 4 g of 3,3'-diazide diphenyl sulfone were mixed with 76 g of methyl ethyl ketone.
A photoresist was prepared by dissolving it in g. This photoresist was spin-coated onto a silicon wafer and dried to form a photoresist i film with a thickness of about 1 μm.

Using a 500 W xenon-mercury lamp as a light source, light was applied to the photoresist film for 1.5 seconds through a chrome mask made of a synthetic quartz substrate. At this time, in order to eliminate the influence of long wavelength light and to prevent the wafer from being heated by infrared rays, a cold mirror that absorbs light with a wavelength longer than 300 nm is used. 300
The photoresist film was exposed to light by reflecting only nm-order light.

In this way, the photoresist film was exposed to deep ultraviolet light with a wavelength of 200 to 300 nm.

When developed with a 0.01 wt% acetic acid aqueous solution and the unexposed portions were dissolved and removed, a linear repeating photoresist pattern with a line width of 1 μm and an interval of 1 μm was formed with extremely high accuracy.

Example 2 Example 1 except that the resist was prepared using poly(4-vinylpyridine) instead of poly(2-vinylpyridine) used in Example 1, and isopropyl alcohol instead of methyl ethyl ketone as the solvent. When pattern formation was performed in exactly the same manner as above, the line width was 1 μm,
Linear repeating photoresist patterns with an interval of 1 μm were formed with extremely high accuracy.

Example 3 Similarly to Example 1, when the azide compounds shown in Table 1 were used instead of the azide compounds used in Example 1,
A linear repeating photoresist pattern with a line width of 1 μm and an interval of 1 μm was formed with high precision.

Example 4 A photoresist film formed by the method described in Example 1 was irradiated with an electron beam using an electron beam lithography device, and developed in the same manner as in Example 1, resulting in a line width of 0.8 μm and a 9-interval of 0.
．． A repeating pattern of 8 μm was formed with high accuracy.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, IJF is capable of forming fine patterns with high precision using an acidic aqueous solution as a developer, and is less toxic and more effective than conventional techniques using an alkaline aqueous solution. Since it has high storage stability, it is particularly effective in reducing the manufacturing cost of semiconductor devices and magnetic bubble memristors.

Claims (1)

[Scope of Claims] 1. A radiation-sensitive composition comprising an acidic aqueous solution-soluble polyvinylpyridine or polyvinylpyridine copolymer and a radiation-sensitive aromatic azide compound. 2. A radiation-sensitive composition, wherein the radiation-sensitive aromatic azide compound according to claim 1 is an azide compound represented by the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, A is an element or substituent that is non-conjugated with the two benzene rings, X is H or N_3, Z is N_3 when X is H, 3. The aromatic azide compound according to claim 2 is 4,4'-diazidiphenyl sulfide, 4,4'
-diazido diphenyl sulfone, 3,3'-diazido diphenyl sulfone, 4,4'-diazido diphenylmethane, 3,3'-dichloro-4,4'-diazido diphenylmethane, 4,4'-diazido diphenyl ether, 4
, 4'-diazidiphenyl disulfide and 4,4
A radiation-sensitive composition characterized in that it is selected from the group consisting of '-diazidobibenzyl. 4. Forming a photoresist film containing an acidic aqueous solution-soluble polyvinylpyridine or vinylpyridine copolymer and an aromatic azide compound on the material on which a fine pattern is to be formed, irradiating a desired portion of the photoresist film with radiation, a step of reducing the solubility of the irradiated portion, a step of developing with an acidic aqueous solution and removing the non-irradiated portion of the photoresist film to form a photoresist pattern, dry etching using the photoresist pattern as a mask,
A pattern forming method comprising the step of forming a fine pattern of the above substance. 5. A pattern forming method, wherein the aromatic azide compound according to claim 4 is an azide compound represented by the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, A is an element or substituent that is non-conjugated with the two benzene rings, X is H or N_3, Z is N_3 when X is H, 6. The aromatic azide compound according to claim 5 is 4,4'-diazidiphenyl sulfide, 4,4'
-diazido diphenyl sulfone, 3,3'-diazido diphenyl sulfone, 4,4'-diazido diphenylmethane, 3,3'-dichloro-4,4'-diazido diphenylmethane, 4,4'-diazido diphenyl ether, 4
, 4'-diazidiphenyl disulfide and 4,4
A method for forming a pattern, characterized in that the pattern is selected from the group consisting of '-diazidobibenzyl.