JPS62136027A - Forming method for pattern of organic film - Google Patents

Abstract

PURPOSE:To highly integrate an element which uses an organic polymer resin film by mixing a compound having an absorption for a photosensitive wavelength of a photoresist in the organic polymer resin film. CONSTITUTION:A compound having an absorption for a photosensitive wavelength of a photoresist 5 is mixed in an organic polymer resin 3 provided as a lifting-OFF material to prevent resist pattern accuracy and resolution from decreasing due to a primary base reflection. The compound having the absorption for the photosensitive wavelength of the photoresist contains dye. For example, in case of using one beam, smiacryl brilliant yellow E5G having an absorption near 430nm is listed. When the dye is used as an absorbent, organic polymer resin is preferably water soluble, and the polymer resin having a group to react with the dye in a molecule can readily hold the dye in the film to enhance the light absorption degree of the film. Thus, the element can be highly integrated.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a polyimide film and a polyacetylene film.

The present invention relates to a pattern forming method for organic films such as LB films and resist films.

BACKGROUND OF THE INVENTION Conventionally, when forming patterns on organic films, there have been problems with etching masks. Usually, when fine pattern processing is required in semiconductor processes, a photoresist, a resin that is sensitive to visible light to ultraviolet light, is used as an etching mask. When these photoresists are used as an etching mask for an inorganic film, the photoresist film is hardly etched under the etching conditions for an inorganic film, and becomes a good etching mask. However, in the case of etching an organic film, the 7-photoresist is not a good etching mask because it is easily etched.

Problems to be Solved by the Invention For example, patterning of a thermosetting polyimide film used as an interlayer insulation film for a protective film and an α-ray prevention film in a semiconductor integrated circuit requires the formation of a resist film on a semi-cured polyimide film. After forming, exposing and developing a resist pattern, wet etching is performed using an alkaline solution such as hydrazine or ethylenediamine. However, since the resist mask is also etched at this time, side etching of the polyimide is accelerated, and even if a 4 pm pattern is formed on the resist pattern, only a polyimide pattern of about 10 .mu.m can be obtained. Furthermore, when patterning a polyimide film using 02 plasma etching, the resist film is easily etched as much or more easily than polyimide under the same conditions, so a thick film mask that is thicker than the polyimide film to be etched is required. Mask pattern accuracy and resolution are reduced.

Means to solve the problem As a method to solve the drawbacks of the conventional method described above, an organic polymer resin film is formed on the organic film using a solvent that does not dissolve the organic film, and an organic silicon oxide film is formed on top of the organic polymer resin film. Then, CF4 reactive ion etching is performed using a resist mask to form a pattern on the organic silicon oxide compound film, and an organic film pattern is formed by dry etching using this as an etching mask. When heated, the organic silicon oxide compound forms a film having etching properties similar to I) the SiC2 film. Therefore, a large etching rate ratio can be achieved in dry etching of an organic film using plasma, and fine patterns can be formed with high precision.

In the present invention, the above method is further improved, and a compound that absorbs the photoresist's sensitive wavelength is mixed into the organic polymer resin used as the lift-off material to prevent resolution degradation due to reflection from the photoresist's base. This realizes improved miniaturization.

Function: In order to form even finer and more precise organic film patterns, the present invention incorporates a compound that absorbs at the photosensitive wavelength of 7-otoresist into the organic polymer resin provided as a lift-off material. Prevents deterioration of resist pattern accuracy and resolution due to reflection. Dyes are examples of compounds that absorb at the wavelength at which photoresists are sensitive.

For example, when using one line, Sumiacryl Brilliant Yellow EGG, which has absorption near 430 nm, is used.
, Sumia Acrylic Yellow N-4G, Sumia Acrylic
Examples include Yellow N-3G, Amido Flavin FFP, Cibacron Brilliant Yellow 3G-P, Kayakalan Yellow GL 143, and Lanahar Fast Yellow 10OFF. In addition, when using G-ray, Cibachloran Blue 8G, Cibachloran Turyuis Blue G, which has absorption near 365 nm,
F-P.

Kayation Tajuis P-NGF, Prussian Tajuis H-A, Sumilite Supra Tajuis
Blue, Gconc, etc. are mentioned.

In addition to dyes, photosensitizers and the like can be cited as light absorbers.

When using a dye as a light absorbing agent, it is desirable that the organic polymer resin is water-soluble. In particular, polymer resins that have groups in their molecules that react with dyes can more easily retain dyes in the film than other resins, and can increase the absorbance of the film. Polymer resins that have groups in their molecules that react with dyes include:
Natural water-soluble polymer resins such as casein, gryu, gelatin, pullulan, and water-soluble dyeable photosensitive resins include monomers containing tertiary amines or quaternary ammonium salts and polymerizable unsaturated bonds, and N-vinylpyrrolidone. copolymers or terpolymers further added with methyl methacrylate, polyvinyl alcohol resins, etc.

Embodiment 1 An embodiment of the present invention in which a resist pattern is formed using lines will be described with reference to FIGS. 1 to 4.

First, an organic polymer resin solution mixed with a dye is prepared. The dye is selected from the dyes for one line described above.

Acidic dyes are used for those having amine groups or amide groups such as casein and gelatin, and direct dyes are used for those having OH groups such as pullulan and cellulose.

Mix dye solution into organic polymer resin solution and heat from 60℃ to 80℃
Stir for 10 to 15 minutes. The liquid mixture is applied onto a substrate 1 such as a semiconductor on which an organic film 2 has been formed, and then heat treated to form a film 3. A solution of organic silicon oxide compound 4 is applied thereon and heat treated to harden the organic silicon oxide compound. Furthermore, resist 5 is applied on top of it and exposed using one line.
develop.

At this time, the resolution and accuracy of resist pattern dimensions are improved by the underlying light-absorbing film (FIG. 1). Then 0.1 Tor
The organic silicon oxide compound film 4 is etched by using CF4 or by active ion etching at a temperature below r.
Then, the organic polymer resin film 3 and the organic film 2 are etched by continuous O2 plasma etching, and the resist 5 is removed at the same time (FIG. 3). Finally, the organic polymer film 3 is dissolved by bubble cleaning using pure water, and at the same time, the organic silicon oxide compound 4 is removed to obtain a pattern of the organic film 2 (FIG. 4).

Effects of the invention By mixing a compound that absorbs at the photoresist's photosensitive wavelength into the organic polymer resin film, it is possible to prevent the resist pattern accuracy and resolution from decreasing due to reflection from the base, and form a clear organic film pattern. Enables high integration of devices using organic films.

[Brief explanation of drawings]

1 to 4 are pattern forming process diagrams according to an embodiment of the present invention. 1...Substrate, 2...Organic film, 3...
...Organic polymer resin mixed with a light absorber, 4...
...organic silicon oxide compound, 5...°photoresist.

Claims (7)

[Claims] (1) A step of forming an organic film on a predetermined substrate, a step of applying an organic polymer resin film using a solvent in which the organic film is not dissolved, and a step of applying a silicon oxide compound solution on the organic polymer resin film. step, forming a photosensitive resin film on the silicon oxide compound film, irradiating it with light through a predetermined mask, and forming a pattern by developing; drying the silicon oxide compound film using the photosensitive resin film pattern as a mask; an etching step, a step of etching the organic polymer resin film and the organic film by oxygen plasma etching using the silicon oxide compound pattern as a mask, and simultaneously removing the resist; a step of etching the organic polymer resin film and the organic film at the same time; In a method for forming a pattern of an organic film, which comprises a step of lifting off the organic polymer film and the silicon oxide film using a solvent in which the film is dissolved, absorption is caused in the organic polymer resin film at a photosensitive wavelength of the photosensitive resin. 1. A method for forming an organic film pattern, the method comprising mixing a compound having the following properties. (2) The method for forming a pattern of an organic film according to claim 1, characterized in that a dye is used as the compound having absorption at the wavelength at which the photosensitive resin is sensitive. (3) A method for forming an organic film pattern according to claim 1, characterized in that a water-soluble polymer resin is used as the organic polymer resin. (4) The method for forming an organic film pattern according to claim 1, characterized in that casein, gelatin, or glue is used as the organic polymer resin. (5) A patent characterized in that a copolymer of N-vinylpyrrolidone and a monomer having a tertiary amine or quaternary ammonium salt or amide group and a polymerizable unsaturated bond is used as the organic polymer resin film. A method for forming an organic film pattern according to claim 1. (6) The method for forming an organic film pattern according to claim 1, wherein a cellulose polymer resin such as pullulan is used as the organic polymer resin. (7) The method for forming an organic film pattern according to claim 1, wherein a polyvinyl alcohol resin or a polyvinylpyrrolidone resin is used as the organic polymer resin.