JPS59202462A - Formation of negative type resist pattern - Google Patents

Abstract

PURPOSE:To form a pattern having superior dry etching resistance, heat resistance and high resolving power with high sensitivity by irradiating a resist film of a polymer contg. quinone diazide with far ultraviolet rays and by heating the irradiated film at a prescribed temp. before development. CONSTITUTION:A resist film of a polymer contg. quinone diazide formed on a substrate is irradiated with far ultraviolet rays of 180-300nm wavelength. The irradiated film is heated at 50-120 deg.C and developed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for forming fine resist patterns in the production of semiconductors, magnetic bubble elements, and optical application parts.

(Prior art) In recent years, there has been an extremely high demand for higher integration of semiconductor integrated circuits, etc., and in line with this, in the field of phosphorography, conventional light (particularly ultraviolet light) has been replaced with electron beams, X-rays, or far ultraviolet light. Light sources with short wavelengths have been used.

In particular, lithography using deep ultraviolet rays is an extension of conventional photolithography, but it can easily perform submicron transfer, and there are great expectations for future microfabrication technology.

By the way, the resist material used for such microfabrication is required to have high sensitivity in the deep ultraviolet region and particularly good resolution, heat resistance, and dry etching resistance, but polymethyl methacrylate (hereinafter abbreviated as PMMA) is It is well known as such a resist for far ultraviolet rays, and exhibits a high resolution of 0.2 μm or less by performing contact exposure using a conformal pull mask. However, this P
MMA has low sensitivity and cannot be said to have sufficient dry etching resistance.

In addition, methacrylic acid ester polymers and methacrylic acid ester copolymers are known as other deep ultraviolet ray resists, but these are not as good as the above-mentioned PMMA especially in terms of dry etching resistance.

That is, a resist material that is highly sensitive to the above-mentioned deep ultraviolet rays, has good resolution, and has high dry etching resistance and heat resistance has not been developed, and there is a need to establish a method for forming such a resist pattern. That is the reality.

(Objective of the Invention) As a result of repeated research in order to solve this problem and meet the above requirements, the present inventors irradiated a resist film made of a polymer containing quinonediazide with far ultraviolet rays and heated it at a predetermined temperature before developing. As a result, it was discovered that a resist pattern having excellent dry etching resistance and heat resistance as well as good resolution can be formed with high sensitivity, thereby achieving the present invention.

(Structure of the Invention) First, the present invention involves irradiating a resist film made of a polymer containing quinonediazide formed on a substrate with deep ultraviolet rays of 180 to 300 nm, heating it at a temperature of 50 to 120°C, and then developing it. This is a negative resist pattern forming method characterized by the following.

In this invention, a resist using a polymer having the aforementioned quinone diazide, specifically, a naphthoquinone 1,2-diazide-5-sulfonic acid ester (hereinafter abbreviated as l) of a novolak resin shown in the example below is irradiated with deep ultraviolet rays. The reason why the sensitivity increases with subsequent heating is considered to be as follows. That is, in LMR, the quinone diazide group undergoes a structural change due to deep ultraviolet rays and becomes insoluble in isoamyl acetate, allowing the formation of a negative resist pattern.

Furthermore, the reason why high sensitivity is exhibited by heating is that the reaction does not proceed 100 times to the final product (insoluble in amyl acetate) by irradiation with far ultraviolet rays alone, and remains as an intermediate substance (insoluble in amyl acetate), which is heated. It is thought that the transition from intermediate substances to final products occurs only after

The lower limit of such temperature conditions is approximately 50°C, and the reason why patterning cannot be performed at temperatures exceeding the upper limit, such as 130°C, is due to this L.
This is because thermal crosslinking occurs due to decomposition of the quinone diazide group at MR temperature of 130° C. or higher, making it insoluble in the solvent.

That is, in the present invention, heating after exposure is within a range of 50 to 120°C which is effective in increasing sensitivity, and most preferably 80 to 110°C.

(Example) The present invention will be specifically explained below with reference to Examples.

Example I LMRE was dissolved in Cernlup acetate, filtered through a 0.2 μm filter, and then coated on an St substrate to a thickness of 0.6 μm. After baking at 60℃ for 30 minutes, 500W
Exposure was performed for 3 seconds, 5 seconds, and 10 seconds using a contact method using an Xe-Hg lamp.

After heating at 100°C for 30 minutes, isoamyl acetate (0
When developed with 0.1% water (added with 0.1% water), the 5 .mu.m line antose was well resolved at the above-mentioned exposure amounts of 3 seconds, 5 seconds, and 10 seconds. The cross-sectional shape of the obtained resist was an Opart Ring shape.

Comparative Example 1 When exposed in the same manner as in Example 1 and immediately developed with the same developer, a no + turn could be formed in the case of 10 seconds, but no pattern could be formed in the case of 3 seconds and 5 seconds. .

Example 2 After exposure was carried out in the same manner as in Example 1, the temperature was set at 50°C and 13°C.
The film was heated at 0°C for 30 minutes and developed in the same manner.

In the case of heating at 50℃, resolution was possible in 5 seconds and 10 seconds, but 3
The resolution was not sufficient in seconds. Further, at 130° C., the pattern did not dissolve in the developer at all, and it was not possible to obtain 9 turns.

(Effects of the Invention) As is clear from the above description, the present invention is capable of forming resists and turns with high sensitivity using deep ultraviolet rays, which have excellent anti-dry etching properties, excellent heat resistance, and excellent resolution. The cross-sectional shape of the pattern obtained is good, with almost overhang as described above, and lift-off of metals such as aluminum and gold is easy, and it can be used directly for manufacturing high-density semiconductor parts, magnetic bubble elements, etc. It has significant industrial utility value as it has remarkable effects.

Patent Applicant: Oki Electric Industry Co., Ltd. Agent, Patent Attorney: Hiroshi Kikuchi Procedural Amendment dated IO, 28th year of 1980, Mr. Kazuinu Wakasugi, Commissioner of the Patent Office, Minor Case Indication, Patent Application No. 76203 No. 2 of 1980, Invention Name negative mold pattern forming method 3, relationship with the case of the person making the amendment Patent Applicant (029) Oki Electric Industry Co., Ltd. 4, Agent 5, Date of amendment order Showa year, month, day (self-motivated) 6, Scope of Claims and Detailed Explanation of the Invention of the Specification Subject to Amendment 7, Contents of Amendment as shown in Attachment 7, Contents of Amendment 1) Correct "2. Scope of Claims" in the Specification as shown in Attachment 7 .

2) On page 3 of the specification, line 8, ``according to'' is corrected to ``consisting of''.

3) On page 3, line 15, ``according to'' is corrected to ``consisting of''.

4) Add the following sentence between lines 14 and 15 on page 4.

Also, since LMR has strong absorption in the far ultraviolet region, the light cannot reach near the substrate. That is, the irradiated area has an upper part, which is a reactive layer, and a lower part, which is an unreacted layer, and the developer tends to seep in between them during development. However, if heating is performed after development, the reaction layer and unreacted layer will have good adhesion9, and pattern defects due to seepage will be eliminated.

5) Page 5, line 6, “Cellsolve” and “Methyl Celunlup”
I am corrected.

6) On page 5, line 12, "ro, o ichi" is corrected to "0.1%."

7] Add the following sentence between lines 1 and 2 on page 6.

Also, some penetration of the developer between the reacted layer and unreacted layer of Resost was observed.

2. Claims A negative characterized by irradiating a 180-300 nm deep ultraviolet ray to a resist film formed on a substrate and made of a polymer having quinonesoisodine, heating it at a temperature of 50-120°C, and then developing it. Method for forming two turns of resist.

Claims (1)

[Claims] A method for forming a negative resist pattern, which comprises irradiating a resist film made of a polymer containing quinone diazide formed on a substrate with deep ultraviolet rays of 180 to 300 nm, heating it at a temperature of 50 to 120°C, and then developing it.