JPS5882244A - Developing solution for rubber type photoresist - Google Patents

Abstract

PURPOSE:To suppress swelling of a rubber type photoresist, and to form a high precision pattern used for manufacture of integrated circuits, by using a developing soln. contg. a 5-12C aliphatic hydrocarbon and a polyol type org. solvent in a specified proportion to said hydrocarbon. CONSTITUTION:A developing soln. is prepared by adding a surfactant or the like, when necessary, to a solvent mixture of a 5-12C aliphatic hydrocarbon, or a combination of >=2 same hydrocarbons, and a polyol type org. solvent, such as ethylene glycol or diethylene glycol monoacetate, in 5-40vol% of said hydrocarbon, in order to enhance developing performance and solubility. The obtained developing soln. is used for developing a rubber type photoresist, such as cyclized cis-1,4-polybutadiene or cyclized cis-1,4-polyisoprene to give a micropattern having about 1.5mum min. width resolution, and no wrinkle, no bending, and no bridging, etc. on the edges of the pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel developer for rubber-based photoresists, particularly an excellent developer capable of developing sharp patterns with fine line widths without swelling the photocured areas of rubber-based photoresists during development. It is related to developer.

Tran, Jista, IC! , LSI, etc., is carried out by photolithography using a photoresist, especially a rubber-based photoresist.

Photolithography involves forming a photoresist layer on a silicon wafer with an oxide film on the surface, exposing the layer to light through a required mask pattern, developing it, and then rinsing it to form the desired resist pattern. It is something that is made to form.

Conventionally, in such photolithography, xylene, an aliphatic hydrocarbon solvent, or a combination thereof is used as a developer, and n-butyl acetate is generally used as a rinsing solution. However, when xylene, an aliphatic hydrocarbon solvent, or a mixture of these is used as a developer, the unexposed areas are completely dissolved and removed, but the photoresist areas (regime pattern) hardened by exposure are Swelling phenomenon occurs, which causes bridging, wrinkles, especially in extremely fine resist pattern areas.
It has been difficult to obtain a resist pattern with high precision due to the curvature or jagged phenomenon. In order to suppress this swelling phenomenon, a so-called rinsing treatment with acetic acid n-butyl ester is usually performed following the development treatment.
No satisfactory effect has been obtained.

In particular, technological progress has been remarkable in recent years, and the degree of integration of semiconductors has increased, for example, 16 kilobits, 64 kilobits,
Furthermore, if it reaches 256 kilobits, it is natural that high resolution of the resist pattern is required, but also minute external dimensional accuracy is required, and it is required to have a minimum line width resolution of around 1.5 μm. It started to be done.

As described above, based on the actual situation that the conventional photoresist pattern, especially the method using the conventional developer that does not cause the swelling phenomenon during development, cannot meet the demands of the semiconductor industry in recent years, the present inventors In order to develop a high-precision photoresist manufacturing technology, we have conducted various studies, especially regarding developing solutions for rubber-based photoresists.As a result, we have effectively overcome the shortcomings of conventional developing solutions for rubber-based photoresists, and are able to produce the desired results with excellent precision. A solvent has been found to obtain photoresist patterns.

That is, the present invention provides a developer for a rubber photoresist comprising an aliphatic hydrocarbon having 5 to 12 carbon atoms and a polyhydric alcohol organic solvent in an amount of 5 to 40% by volume based on the aliphatic hydrocarbon.

The aliphatic hydrocarbons having 5 to 12 carbon atoms, which are the main components of the developer of the present invention, are n-pentane, n-hexane, n-
-hebutane, n-octane, n-nonane, n-decane,
n-undecane, n-dodecane and their isomers, which can be used alone or in combination of two or more.

In addition, in the present invention, the polyhydric alcohol organic solvent which is another component mixed with the above aliphatic hydrocarbon is a mono-lower alkyl of a hydroxyl compound such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol or diethylene glycol monoacetate. Ethers and mono-7enyl ethers, such as monomethyl ether, monoethyl ether, and monopropyl ether.

Representative examples include monobutyl ether and monophenyl ether. These can also be used alone or in combination of two or more.

The developer of the present invention contains the above aliphatic hydrocarbon and 5 to 4 of the above aliphatic hydrocarbons.
A mixed solvent consisting of the above-mentioned polyhydric alcohol-based organic solvent in an amount range of 0% by volume, and when used as a developer for rubber-based photoresist, it effectively suppresses the swelling phenomenon of the photoresist portion, thus accompanying the swelling. There are no various inconvenient phenomena caused by this method, and a resist pattern with excellent precision can be easily obtained.

If the amount of the polyhydric alcohol-based organic solvent mixed with the aliphatic hydrocarbon is less than 5% by volume, it will cause swelling of the resist pattern like a conventional developer, and the object of the present invention cannot be achieved. If it exceeds 60% by volume, the developing power will decrease and it will not function as a developer. The preferred mixing ratio of the polyhydric alcohol organic solvent to the aliphatic hydrocarbon is 10 to 35% by volume.

In addition, for aliphatic hydrocarbons other than those having 5 to 12 carbon atoms, a mixture of polyhydric alcohol-based organic solvents does not have excellent developing ability as a developer for rubber-based photoresists. be.

The developer of the present invention can be applied to known rubber photoresists. An example of such a rubber photoresist is 1,2-polybutadiene.

1. Polymers containing butadiene as one constituent, such as 2-polybutadiene cyclization products, cis-1,4-polybutadiene cyclization products, trans-1,4=polybutadiene cyclization products, and styrene-butadiene copolymer cyclization products, and derivatives thereof cyclized products of natural rubber, cyclized products of cis-1,4 polyisoprene, cyclized products of trensu-1,4-polyisoprene, and cyclized products of styrene-isoprene copolymers, and polymers containing isoprene as one component; A photoresist containing a cyclized derivative thereof as a main component and containing a photocrosslinking agent can be mentioned.

In particular, a preferred polymeric photoresist to which the present invention is applied has a number average molecular weight of 30,000 to 200,000.

A photoresist using the above cyclized product with a degree of cyclization of 30 to 85%, and optimally a cyclized product of cis-1,4-polybutadiene, a trans -1,4-polybutadiene cyclized product, trans-1,4-polyisoprene cyclized product, or cis-1,4-polyisoprene cyclized product is used as a photoresist. Among these, it is suitable for photoresists using trans-1,4-polyisoprene cyclized products or cis-1,4-polyisoprene cyclized products. Examples of such photoresists include 0MR83 (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) and KMR74.
There are commercially available products such as 7 (product name, manufactured by Eastman Kodak Company) and Waycoat Type 3 (product name, manufactured by Phillip A/Temento Chemical Company).

Note that the developability, particularly the solubility, can be improved by adding a surfactant, such as a fatty acid ester nonionic surfactant, to the developer used in the present invention.

When developed using the rubber-based photoresist developer of the present invention, bridging, wrinkling, drooping, and jaggedness of the resist pattern will not occur, and it is extremely advantageous for forming fine patterns of around 1.5 μm. Furthermore, since the developing solution of the present invention has a large tolerance in developing rubber-based photoresists, even if the developing time is excessive, there will be no problem with the resist pattern, and it is also excellent in practical use. .

Next, the present invention will be explained in more detail with reference to Examples.
rubber-based photoresist on the wafer) 0MR83 (product name,
(manufactured by Tokyo Ohka Kogyo Co., Ltd.) with spinner coating, 80
The film thickness is 800℃ after 20 minutes in an open oven kept warm at ℃.
A photoresist layer of 1.0 nm thick was formed. Then, on top of that,
A resolution test chart made by four people was superimposed, and contact exposure was performed for 2 seconds in a nitrogen atmosphere using a 200 W ultra-high pressure mercury lamp. Subsequently, it was immersed in a developer consisting of 70% by volume of n-butyl and 30% by volume of ethylene glycol monoethyl ether acetate, and developed for 1 minute. There were no fine wrinkles, sag, or creases in the resulting resist turns, and a sharp pattern with a line width of 1.5 μm was obtained, with no need for rinsing.

For reference, 1 in subsequent acetic acid n-butyl ester
When the resist pattern was immersed for a minute and rinsed, no side step change was observed in the resist pattern.

Example 2 A resist was turned in the same manner as in Example 1 except that a mixed solution of 70% by volume of n-hexane, 10% by volume of ethylene glycol monomethyl ether and 20% by volume of hyethylene glycol monomethyl ether acetate was used as the developer. formed.

As a result, as in Example 1, no swelling phenomenon occurred in the resistive turns, and the minimum line width was 1.5 mm, faithful to the test chart.
A 5 μm pattern could be reproduced.

Example 3 Saturated aliphatic hydrocarbon mixture having 8 to 11 carbon atoms (trade name: Isono (manufactured by -01 Kotsun Chemical Co., Ltd.)
80% by volume, ethylene glycol monoethyl ether 1
Buttering was carried out in the same manner as in Example 1, except that a mixed developer containing 0% by volume and ethylene glycol monoethyl ether acetate (IQ)% by volume was used. There was no swelling in the resist pattern, and a minimum line width of 1.5 μm could be resolved.

Further, when the resist pattern was observed after being immersed in a developer for 3 minutes, there was no disturbance of the resist pattern due to excessive development.

From this, it can be seen that the present developer has a wide permissible range of development conditions and is extremely desirable from a practical standpoint.

Comparative Example 1 Patterning was carried out in the same manner as in Example 1 using a conventionally used developer consisting of a mixture of 70% by volume of n-heptane and 30% by volume of xylene. When rinsed for 1 minute with I was also given an older brother. The minimum line width that can be practically used with this Ω developer is 4 μm, and it has been found that patterns with line widths smaller than this cannot be formed.

Furthermore, when the rinsing treatment was not performed, the resist swelled so much that it was not possible to form fine lines of 6 μm or less.

Comparative Example 2 After developing in the same manner as in Comparative Example 1, excessive development for 1 minute was repeated three times.As the development times continued, the swelling of the resist pattern became more severe. Patent applicant Tokyo Ohka Kogyo Co., Ltd. agent
Akira Agata

Claims (1)

[Scope of Claims] 1. A rubber-based photoresist developer 2 comprising an aliphatic hydrocarbon having 5 to 12 carbon atoms and a polyhydric alcohol-based organic solvent in an amount of 5 to 40% by volume based on the aliphatic hydrocarbon. Polyhydric alcohol organic solvents are ethylene glycol and ethylene glycol monoacetate. 2. The developing solution according to claim 1, which is monomethyl ether, monoethyl ether, monopropyl ether, motubutyl ether or monophenyl ether of diethylene glycol or hashethylene f-li:7-monoacetate.