JPS59105339A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain an electrically excellent electrode contact and a wiring while improving the coverage of a cover oxide film by preventing the side etching of a wiring polysilicon layer by a silica film. CONSTITUTION:An oxide film 12 is formed on one main surface of a P type single crystal silicon substrate 11 through a vapor phase growth method, and a polycrystalline silicon film 13 for the wiring, aluminum 14 and a silicon thin- film 15 as a reverse whisker preventive film for a photo-resist by the reflection of beams are applied. The photo-resist 16 is patterned to a predetermined pattern. The film 13, aluminum 14 and the thin-film 15 are etched while using the photo-resist 16 as a mask, and the photo-resist 16 is removed. A silica film 17 is applied, and the silica film is baked at a low temperature and solidified. The thin-film 15 and the film 17 are etched until the silica thin-film 15 is removed through an etching method, and the cover oxide film 18 is grown through a vapor phase growth method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device that can obtain electrically good electrode contact and wiring by eliminating side etching of a polycrystalline conductive layer for wiring.

FIGS. 1(a) to 1(e) show a conventional method of manufacturing a semiconductor device. This manufacturing method is shown in Figure 1(a).
As shown in FIG. 2, an oxide film 2 (by vapor phase growth method) is formed on the surface of a P-type nested crystalline silicon substrate 1, and then a polycrystalline silicon film 3 for wiring, aluminum 4, and a photoresist film are formed by reflecting light. A thin silicon film 5 serving as a sink prevention film is deposited. Next, as shown in FIG. 1('b), the 7-photoresist 6 is patterned into a predetermined pattern. This photoresist 6 is used as a mask for etching, and then the photoresist 6 is removed to obtain FIG. 1(C). Next, when the silicon thin film 5 is etched, it becomes as shown in FIG. 1(d). If bonding is performed on the butt portion with this silicon thin film 5 remaining, the bonding strength will be weak. Thereafter, a SiC cover oxide film 7 is deposited by vapor phase growth to obtain the structure shown in FIG. 1(e).

In the method for manufacturing a semiconductor device formed in this manner, when the silicon thin film 5 is etched, wiring vol. J/M(3
) are also etched, making it impossible to obtain good electrical electrode contact and wiring. Further, side etching of the wiring polysilicon deteriorates the coverage of the cover oxide film and may cause cracks.

The present invention has been made in view of the above points, and an object of the present invention is to prevent side etching of the polysilicon layer 3 when etching the silicon thin film 5, and to ensure electrically good electrode contact and wiring. The present invention provides a method for manufacturing a semiconductor device such that the semiconductor device can be obtained.

The semiconductor device of the present invention includes the steps of: forming an insulating film on the entire surface of a semiconductor substrate having a conductivity type; forming a polycrystalline conductive layer for wiring on the insulating film and a metal conductive layer thereon; A step of forming a silicon thin film on the metal conductive layer, which serves as a film to prevent reverse sinking of the photoresist due to light reflection, and forming the polycrystalline conductive layer, the metal conductive layer, and the silicon thin film into a predetermined shape using the photoresist as a mask. a step of removing the photoresist, a step of applying a silica film so as to cover a polycrystalline conductive layer for wiring, and a step of etching the silica film on the silicon thin film and the silicon thin film. The manufacturing method of the present invention includes: Accordingly, when etching a silicon thin film, the advantage of covering it with a wiring polysilicon layer (crystalline film) is that there is no side etching and electrically good f2 electrode contact and wiring can be obtained. This silica film provides good coverage of the cover oxide film.

Next, embodiments of the present invention will be explained using drawings. 3j Figures 2(a) to 2(f) are cross-sectional views for explaining a method of manufacturing a semiconductor device to which an embodiment of the present invention is applied. It is.

A silicon oxide film 12 is formed on the surface of a P-type crystalline silicon substrate 11 by a vapor phase growth method, and then a polycrystalline silicon film 13 for wiring, aluminum 14, and a photoresist anti-sink film due to light reflection are formed. A silicon thin film 15 is deposited. Next, the photoresist 16 is patterned into a predetermined pattern.

This photoresist 16 is used as a mask for etching, and then the photoresist 16 is removed to obtain the pattern shown in FIG. 2(C).

Next, a silica film was applied, and then the silica film was baked with low electric current 1 to harden it, as shown in FIG. 2(d). Next, the silicon thin film 15 is etched by an etching method to obtain the image shown in FIG. 2(e).

Next, a small cover oxide film 18 is grown using a vapor phase growth method to form a second cover oxide film 18.
Figure (f) is obtained.

The method for manufacturing a semiconductor device manufactured as described above can obtain good electrode contact and wiring against stains by preventing side etching of the wiring polysilicon layer with a silica film. Moreover, this silica film improves the coverage of the cover oxide film.

[Brief explanation of the drawing]

FIGS. 1(a) to 1(e) are cross-sectional views showing a conventional method of manufacturing a semiconductor device, and FIGS. 2(a) to 2(f)
1A and 1B are cross-sectional views of each manufacturing process when implemented in manufacturing an N-channel type silicon integrated circuit device according to the present invention. In the same figure, 1.11...4P type single crystal silicon substrate, 2.12...CVD oxide film, 3.13. Polycrystalline silicon IJ:+n film, 4.14 ...Aluminum electrode, 5.15...Silicone crucible membrane, 6.16
...Photoresist, 7.18...C
VD acid (111m, 17... curved silica film, /sil (α) ζ' (bn/171 (C) '\-/ (d) (e) 1st concave to Figure 1// / (0-) 97// <b> l/ /-also/ <C> 2nd z Crt) /3 ,,A-/'/ (e) (,7') 2nd review

Claims (1)

[Claims] A step of forming an insulating film on the entire surface of a semiconductor substrate having one conductivity type, a step of forming a polycrystalline conductive layer for wiring on the insulating film and a metal conductive layer thereon, and a step of forming a polycrystalline conductive layer for wiring on the insulating film and a metal conductive layer thereon; a step of forming a silicon thin film to serve as a reverse sink prevention film for the photoresist due to reflection of the photoresist, and a step of patterning the polycrystalline conductive layer, the metal conductive layer, and the silicon thin film into a predetermined shape using the photoresist as a mask; Manufacturing a semiconductor device, comprising the steps of removing the photoresist, thereafter applying a silica film to cover the polycrystalline conductive layer for wiring, and etching the silica film on the silicon thin film and the silicon thin film. Method.