JPS6366937A - Forming method of pattern of silicon group film - Google Patents

Abstract

PURPOSE:To form an silicon group film according to a pattern under a uniform state having no crack by removing and treating a resist film by plasma at a treatment temperature of a specific value or less. CONSTITUTION:When an silicon group film is etched, using a photo-resist as a mask, the photo-resist is gotten rid of through plasma treatment using a gas mainly comprising oxygen and the pattern of the silicon group film is shaped, the plasma treatment is conducted at a treatment temperature of 120 deg.C or less. It is preferable that said silicon group film being a material consists of an silicone group resin, is prepared as an applying liquid and can form the silicon group film through baking. The so-called induction type plasma treater to which a plasma discharge section and a reaction treating section are mounted is particularly preferable as a plasma treater conducting plasma treatment satisfying said conditions.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a method for forming a pattern on a silicone film,
More specifically, we manufacture silicone-based coatings that are useful as electronic materials in a uniform, crack-free state.

The present invention relates to a method for forming a pattern in a state in which a pattern is formed.

[Conventional technology]

Silicone coatings have excellent insulation, heat resistance, and stability, and are therefore widely used in the field of electronic materials. for example,
In the field of manufacturing semiconductor devices such as VLSI, interlayer insulating films in multilayer wiring processes (Japanese Patent Publication No. 60-46826), and in the field of manufacturing liquid crystal display devices, alignment films (Japanese Patent Laid-Open No. 60-25851), etc. It is often used for

By the way, when manufacturing various electronic materials using these silicone-based films, a step of patterning the silicone-based film is usually performed. To pattern the silicone coating, a photoresist coating is formed on the silicone coating, the photoresist is patterned using a conventional lithography technique, and the exposed silicone coating is etched using the RIE method using the photoresist as a mask. This is done by removing the photoresist mask by plasma treatment using a gas containing oxygen as the main component.

However, this method has the problem that cracks tend to form in the silicone film when plasma processing is performed using a gas mainly composed of oxygen, which is used as a photoresist mask for etching the silicone film. It was not possible to obtain a patterned silicone film. To solve this problem, for example, 8102 or fiJ-203 is laminated between polysilsesquioxane, which is a type of silicone coating, and photoresist. By doing so, the stress applied to the silicone coating during plasma treatment to remove the patterned photoresist is alleviated and cracks are prevented from occurring (Japanese Patent Application Laid-open No. 111046/1983).

However, since this method requires the formation of yet another film on top of the silicone film, the work is complicated and costly, and it is not a practical method.

[Problem that the invention seeks to solve]

The present invention has been made to solve the above-mentioned problems and to provide a method for forming a uniform pattern without cracks on a silicone film useful as an electronic material.

[Means for solving problems]

As a result of extensive research to achieve the above object, the present inventors have found that after dry etching a silicone film using a patterned resist film as a mask, the resist film is removed by plasma at a processing temperature of 120°C or less. The inventors have discovered that the object can be achieved by carrying out the following steps, and have come up with the present invention.

That is, the present invention is a method in which a silicone film is etched using a photoresist as a mask, and then the photoresist is removed by plasma treatment using a gas containing oxygen as a main component to form a pattern of a silicone film. This is a method for forming a pattern of a silicone film, characterized in that it is carried out at a processing temperature of 120° C. or lower.

The present invention will be explained in detail below.

The method of the present invention uses a gas containing oxygen as a main component, and uses
Since the resist film on the silicone coating is removed by plasma treatment at a temperature below ℃, any plasma processing equipment that can perform plasma processing that satisfies this condition can be used. However, a particularly preferred plasma processing apparatus is a so-called induction type plasma processing apparatus that is provided with a plasma discharge section and a reaction processing section. Since this induction type plasma processing apparatus has a structure in which a plasma discharge section and a reaction processing section are provided in the same chamber, the processing temperature can be lowered.

In addition, in general, in plasma processing, as the plasma processing time becomes longer, the temperature inside the reaction processing section increases, so it is not preferable to use a so-called patch-type plasma processing apparatus that processes multiple substrates at the same time, but instead processes one substrate at a time. A single-wafer type plasma processing apparatus is preferred. However, the method of the present invention is not limited to the plasma processing apparatus having the above structure as long as it can perform plasma processing at a temperature of 120° C. or lower.

The silicone coating used in the present invention is made of silicone resin, and its type is not particularly limited, but it can be prepared as a coating solution and formed into a silicone coating by baking. is preferred. The silicone resin used may be one in which the Si atom is contained in the main chain, in the side chain, or in the main chain and the side chain, and specifically, polysiloxane, polyladder organosiloxane, etc. , polysilazane, polysilane, polysilsilane, polysilmethylene, polysilylphenylene, polyphenyleneoxysiloxane, polysilsesquioxane, bo! l (p-to')
methylsilylstyrene), poly(trimethylvinylsilane), phenyl! A coating solution prepared by dissolving silicone resin such as triphenylsiloxysilanediol-bisphenol copolymer alone or in combination of two or more in an organic solvent, and a coating solution obtained by hydrolyzing an alkoxysilane dissolved in an organic solvent. coating liquid, diaminoborisiloxa/
Examples include a coating liquid obtained by dissolving a polyimide-silicone resin, which is a reaction product of a mixture of an organic diamine and a tetracarboxylic acid, in an organic solvent.

Organic solvents and alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and methyl alcohol, ketones such as acetone, methyl ethyl ketone, and acetylacetone, methyl acetate, ethyl acetate, and butyl acetate are used to prepare such coating solutions. Examples include esters such as ethylene glycol, glycerin, diethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, polyhydric alcohols such as propylene glycol, and their ethers. These may be used alone or in combination of two or more.

The above-mentioned coating liquid is applied by a commonly used coating method such as a spinner method, a dipping method, a spray method, a screen printing method, a roll coater method, or a brush coating method, and is preferably applied at a temperature of 150° C. or higher in air or an inert gas. A silicone film is formed by baking at 300°C or higher.

In the pattern forming method of the present invention, after dry etching a silicone film using a resist film as a mask,
The resist film is removed by plasma processing using a gas containing oxygen as a main component at a processing temperature of 0.degree. C. or lower. Specifically, the gas containing oxygen as a main component is preferably one containing 80 volumes of oxygen or more, and other gases that can be mixed include CHF5, C2F6, C3F8, C4FB, and C3F10.
By mixing these fluorine-based gases, the speed of removing the resist film can be improved, and the resist film can be removed by plasma treatment at a low temperature. Furthermore, if the amount of oxygen gas is less than 80 volumes, it takes time to remove the resist film, and the temperature inside the plasma processing section becomes high, which is not preferable because it is not possible to obtain a uniform silicone coating without cracks.

In the method of the present invention, plasma processing is performed at a processing temperature of 120°C or lower;
Exceeding this is not preferable because cracks are likely to occur in the silicone coating.

Further, the lower limit of the treatment temperature cannot be particularly limited, but it is practically room temperature, and a particularly preferable treatment temperature range is 50 to 1
It is 00℃. The processing temperature in the present invention is measured as the temperature of the stage on which the substrate to be processed is placed.

〔Example〕

(Creation of test board) Silicone resin Glass Re5inGR-650
(Silicone Ladder Polymer manufactured by Owens-Illinois) was made into a 20% by weight butyl alcohol solution, which was coated on a silicon substrate, and then subjected to beta testing at 200° C. for 30 minutes to obtain a silicone-based coating with a thickness of approximately 1 μm. Next, a positive photoresist, 0FPR-800 (
(manufactured by Tokyo Ohka Kogyo Co., Ltd.) according to a conventional method, and the exposed silicone film was selectively etched by RIE to prepare test substrates to be used in the following Examples and Comparative Examples.

Example 1 The test board was a TCA-23, which is an induction plasma processing apparatus consisting of a plasma generation section and a plasma processing section.
00 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), a mixed gas consisting of 95% oxygen by volume and 5 parts by volume of nitrifluoromethane was introduced, and the positive temperature was set at an output of 250 W, a pressure of 0.8 Torr, a treatment temperature of 50°C, and a treatment time of 30 seconds. When the mold photoresist was removed, the photoresist was completely removed and no cracks were observed in the silicone coating, forming a uniform pattern of the silicone coating.

Example 2 Silicone resin and silicone varnish KR-285 (
40f (manufactured by Shin-Etsu Chemical Co., Ltd.) dissolved in ethyl alcohol 602 is used as a coating liquid, and using this coating liquid,
A pattern of a silicone film was formed in the same manner as in Example 1 except that a silicone film obtained by baking at 00°C for 30 minutes was used, and a uniform pattern without cracks was obtained.

Comparative Example 1 The test board was used in a batch type plasma processing apparatus, ○P, which has an integrated structure of a plasma generation section and a plasma processing section.
Using M-A1200 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), oxygen 9
When a positive photoresist was removed under conditions of an output of 250 W, a pressure of 0.8 Torr, and a processing temperature of 150 to 200°C by introducing a mixed gas consisting of 5% by volume of nitrifluoromethane, many cracks were found in the silicone film. A peeling phenomenon from the silicon substrate was observed.

Comparative Example 2 The test substrate was used in an OPM, which is a single-wafer plasma processing apparatus having an integrated structure of a plasma generation section and a plasma processing section.
- When positive photoresist was removed using EM800 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) by introducing oxygen gas and under conditions of an output of soow, a pressure of 1.2 Torr, and a processing temperature of 200°C, the photoresist was completely removed. , many cracks had occurred in the silicone coating.

〔Effect of the invention〕

The pattern forming method for silicone coatings of the present invention eliminates cracks in silicone coatings, which have been a problem in conventional plasma processing using gas containing oxygen as the main component.
This can be prevented by plasma treatment at a processing temperature of 0°C or less, so it is possible to obtain a uniform coating without cracks in the pattern formation of silicone-based coatings used as interlayer insulation films, especially in multilayer wiring processes. It is extremely effective because it allows

Furthermore, since the method of the present invention is effective for all types of silicone-based coatings, it can also be fully utilized for silicone-based coatings used as electronic materials such as interlayer insulating films, passivation films, and electrode protection films.

Claims (1)

[Claims] A method in which a silicone film is etched using a photoresist as a mask, and then the photoresist is removed by plasma treatment using a gas containing oxygen as a main component to form a pattern of the silicone film, wherein the plasma treatment is carried out at temperatures below 120°C. A method for forming a pattern on a silicone film, characterized in that it is carried out at a processing temperature of