JPS59107098A - Electrolytic etching treatment - Google Patents

Abstract

PURPOSE:To obtain an etching shape having extremely a good follow-up characteristic to a solid in electrolytic etching treatment on the surface of the solid or solid film by adding a liquid crystal to an electrolytic etching soln. CONSTITUTION:An electrolytic etching soln. 22 added with a liquid crystal 25 is filled in an electrolytic film 21, and a sample 23 wherein a figure-shaped resist film formed to etch electrolytically an Al film into a figure shape is formed on the surface of the SiO2 film formed on the surface of Si and a platinum plate 23 to serve as a cathode plate are dipped in the soln. 22. An anode electrode is connected to the Al film on the sample 23 and a cathode to the plate 24 and electrolytic etching is performed. The liquid crystal 25 dissolved in the soln. 22 or dispersed by a dispersant is arrayed in the electric field direction in such electrolytic etching and the etching shape having a good follow-up characteristic to the figure with <=0.1 micron side etching rate (y) is obtd.

Description

[Detailed description of the invention] The present invention relates to a Vi electrolytic etching treatment method.

Conventionally, in the electrolytic etching treatment method, for example, when electrolytically etching an a film on a Bi 02 film completely formed on the surface of a Si wafer, a method as shown schematically in FIG. 1 is used.

That is, the electrolytic container 1 is filled with a phosphoric acid aqueous solution (85%) 2, and the phosphoric acid aqueous solution 2 is filled with water for electrolytically etching the surface KAI film of the a film on the 5iox film formed on the Si surface into a figure shape. A sample 3 on which a patterned resist film is formed is immersed in a platinum plate 4 which serves as a negative plate, and an anode electrode is connected to the am of the sample 3, and a cathode is connected to the platinum plate 4. Then, electrolytic etching is performed.

In the electrolytic etching according to the conventional technique as described above, as shown in FIG. There was a drawback that the dimensional correspondence with the resist figure 3 was poor, such as the side e and notch edges being about 1 micron.

It is an object of the present invention to eliminate the drawbacks of the prior art and to provide an electrolytic etching method with extremely good pattern followability.

The basic structure of the present invention for achieving the above object is characterized in that liquid crystal is added to an electrolytic etching solution during electrolytic etching treatment from the surface of a solid or a solid film.

Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 3 is a schematic diagram for explaining the electrolytic etching method according to the present invention. The electrolytic film 21 is filled with an electrolytic etching solution 22 to which the liquid crystal 15 has been added, and the Kkt film formed on the KFiBi surface in the electrolytic film 21 is electrolyzed on the surface of the At film on the Si02 film in the shape of a figure. The sample 23 on which the patterned resist film formed for etching is formed and the platinum plate 24 which will become the cathode plate are immersed.
An anode electrode is connected to the At film 24, a cathode is connected to the platinum plate 24, and electrolytic etching is performed.

In electrolytic etching using this technology as described above,
Liquid crystals (MBBA: paramethyl oxybenzylidene para-aniline) dissolved in the electrolytic etching solution or dispersed by a dispersant are aligned in the direction of the electric field, resulting in side etching amount y = 0 as shown in Figure 4. ．．
It is effective because an etched shape with good pattern followability of 1 micron or less can be obtained.

The present invention can also be applied to adjacent oxidation methods.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the electrolytic etching method according to the prior art, FIG. 2 is a cross-sectional shape of the electrolytically etched film according to the prior art, FIG. 3 is a schematic diagram showing the electrolytic etching method according to the present invention, and FIG. 4 is the present invention. 1 shows a cross-sectional shape of an electric field etched film according to the invention. 1.21... Electrolytic bath 2.22... Electrolytic etching solution 3.23...
...Sample 4.24...Anode plate 25...Liquid crystal 11.31...Substrate 12.32...River/U film 13.33...Resist for the applicant Suwa Seikodai Co., Ltd. Agent Patent Attorney Tsutomu Mogami

Claims (1)

[Claims] An electrolytic etching method characterized in that liquid crystal is added to a snow-melting etching solution in electrolytic etching from the surface of a solid or a solid film.