JPH03169011A - Semiconductor manufacturing apparatus - Google Patents

Abstract

PURPOSE:To remove an oxide film grown on the surface of a polysilicon film and to etch the polysilicon film stably by a method wherein, before the film is etched by using an etching apparatus, it is treated with hydrofluoric acid. CONSTITUTION:An oxide film 1 grown on a polysilicon film 2 is etched completely by introducing hydrofluoric acid in a gas state from an introduction port 6. After that, an evacuation operation is executed from an evacuation port 7; electrodes 4, 5 are moved downward; a gas is introduced from a gas port 10 at a lower stage of an etching chamber; a high frequency wave is applied at the lower stage of the etching chamber 9; the polysilicon film 2 on a semiconductor substrate 3 which has been set on the lower-part electrode 4 and which has the polysilicon film 2 is etched. At this time, the hydrofluoric acid is not mixed with an etching gas of the polysilicon film 2. Thereby, the polysilicon film can be etched with good uniformity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an etching apparatus for polysilicon films.

[Summary of the invention]

This invention uses a polysilicon film etching device to perform hydrofluoric acid treatment before etching to remove the oxide film that has grown on the surface of the polysilicon film, making it possible to stably etch the polysilicon film. This is what I did.

[Conventional technology]

Conventionally, the etching of the polysilicon film 2 shown in FIG. 2 is performed without any treatment before etching.

Alternatively, hydrofluoric acid treatment is performed using a separate device before etching.

[Problem to be solved by the invention]

However, the conventional method has the disadvantage that the etching of the polysilicon film 2 is largely bulky within the wafer due to variations in the thickness of the oxide film 1 formed on the surface of the polysilicon film 2. Furthermore, even when hydrofluoric acid treatment is performed using a separate device before etching, a new oxide film 1 is formed on the surface of the polysilicon film 2 by the time the polysilicon film 2 is etched, and the polysilicon film 2 is etched. However, it had the disadvantage of being barracked within the wafer. Therefore, in order to solve these conventional drawbacks, the present invention aims to remove the oxide film l in an etching apparatus for the polysilicon film 2.
The purpose is to provide a device that can also perform etching.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides the etching chamber 9 with a two-stage structure so that the etching of the oxide film 1 and the etching of the polysilicon film 2 can be performed using the same etching apparatus.

[Effect]

As described above, by making the etching chamber 9 have a two-stage structure, the oxide film 1 can be quickly etched using gaseous hydrofluoric acid in the upper stage, and the polysilicon film 2 can be etched with good uniformity in the lower stage. . In addition, since it has a two-stage structure, the hydrofluoric acid and the etching gas for the polysilicon film 2 do not mix, and the exhaust gas is separated, so there is no problem with safety.

C Example] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 ta+ shows polysilicon ll! deposited on the lower electrode 4 in the upper stage of the etching chamber 9. 2 and a semiconductor substrate 3 having an oxide film 1 formed on the polysilicon film 2, gaseous hydrofluoric acid is introduced from the inlet 6 to completely etch the oxide film 1 formed on the polysilicon film 2. do.
After that, exhaust air from the exhaust port. Next, Figure 1 (bl
Move the electrodes 4 and 5 downward, introduce gas from the gas flow tube 10 at the lower stage of the etching chamber 9, and ignite high frequency waves at the lower stage of the etching chamber 9 to form the polysilicon film 2 cennotated on the lower electrode 4. The polysilicon film 2 of the semiconductor substrate 3 is etched.

〔Effect of the invention〕

As described above, the present invention makes it possible to etch a polysilicon film with good uniformity by providing two stages of etching chambers.

[Brief explanation of the drawing]

Figures 1(a) and (bl are cross-sectional views of the etching equipment used to etch an oxide film and polysilicon film, respectively, using the polysilicon film etching equipment of the present invention, and Figure 2 is a cross-sectional view of the polysilicon film etching equipment of the present invention. This is a cross-sectional view of l...Oxide film 2...Polysilicon film 3 - Semiconductor substrate - Lower electrode - Upper electrode - Hydrofluoric acid inlet - Hydrofluoric acid exhaust port - Gas exhaust port - Etching chamber - Gas inlet

Claims (1)

[Claims] A semiconductor device characterized in that a polysilicon film etching apparatus performs hydrofluoric acid treatment before etching.