JPH0346328A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent a difference in level from being produced between a field region and an active region by a method wherein a resist, an oxide film and a nitride film are etched, under a dry etching condition having no selectivity, until nitrogen cannot be detected. CONSTITUTION:A LOCOS oxide film 1 is formed in a part which is not covered with a LOCOS nitride film 2; a resist 4 is coated in such a way that a surface shape becomes flat. The resist 4, the LOCOS oxide film 1 and the LOCOS nitride film 2 are etched under a dry etching condition having no selectivity until nitrogen cannot be detected. By such a treatment, they are etched while keeping the flat surface shape as coated with the resist; since a layer containing nitrogen does not exist other than the LOCOS nitride film, this etching operation can be finished when the LOCOS nitride film has been etched completely. Thereby, a part between a field region and an active region can be flattened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a semiconductor device using a LOCOS process.

[Summary of the invention]

In the present invention, a resist is applied to the step between the field region and the active region that occurs in the LOCOS process, and the resist, oxide film, and nitride film are planarized by non-selective etching.

[Conventional technology]

FIG. 2 is a step-by-step sectional view of a conventional method for manufacturing a semiconductor device. In FIG. 2+al, the LOCO3 oxide film 1 is formed in the part not covered by the COS nitride film 2,
By removing the LOCO3 nitride film 2 with phosphoric acid, it becomes as shown in FIG. 2 (bl).

[Problem to be solved by the invention]

In the conventional technology, there is a problem that a difference occurs between the field region and the active region, which adversely affects the shape of the wiring and deposited film formed on this difference.

[Means to solve the problem]

In order to solve these problems, the present invention
After oxidation, a resist was coated, and the resist, oxide film, and nitride film were etched under non-selective dry etching conditions until nitrogen could no longer be detected.

[Effect]

When processed as described above, the resist and LOCOS are coated while maintaining the flat surface shape when coated with resist.
The oxide and LOCOS nitride are etched and the LO
Since there is no layer containing nitrogen other than the COS nitride film, LOCO
Etching can be terminated when the S nitride film is completely etched.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1(a) to 1fcl are cross-sectional views in the order of steps of the method for manufacturing a semiconductor device according to the present invention. In Figure 1 fat, LOC
A LOCO3 oxide film 1 is formed on a portion not covered with the O3 nitride film 2, and is coated with a resist 4 so that the surface shape becomes flat in the area shown in FIG. The resist 4, LOCO3 oxide film 1, and LOCO8 nitride film 2 are etched under non-selective dry etching conditions until nitrogen can no longer be detected, resulting in the result shown in FIG. 1(C).

[Effects of the Invention] According to the present invention, since the area between the field region and the active region is flattened, the wiring and deposited film formed thereon can be easily processed, and the performance of the semiconductor device can also be improved. I can do it.

[Brief explanation of drawings]

FIGS. 1(a) to 1(c) are step-by-step cross-sectional views of a method for manufacturing a semiconductor device according to the present invention, and FIGS. 2(a-1, c) are step-by-step cross-sectional views of a conventional method for manufacturing a semiconductor device. l...LOCO3 oxide film 2...Ll) CO3 nitride film 3...Substrate 4...Resist or higher

Claims (1)

[Claims] After LOCOS oxidation, a process of coating a resist, and a process of etching the resist, a LOCOS oxide film, and a LOCOS nitride film under non-selective etching conditions until nitrogen in the nitride film is no longer detected. Production method.