JPH03291935A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the generation of cracks in a PSG protecting film by forming unevenness on the surface of an interlayer insulating film turning to a substratum of an Al power supply wiring. CONSTITUTION:A field oxide film 200 is formed on a first conductivity type semiconductor substrate 100; an interlayer insulating film 300 of a poly Si-Al wiring is formed on the film 200; an Al power supply wiring 400 is formed by using the the film 300 as a substratum. In this semiconductor device, unevenness is formed on the surface of the interlayer insulating film 300. For example, the field oxide film 200 is formed on a first conductivity type semiconductor substrate 100 for an IC; a diffusion region 601 is finely formed; thereon the interlayer insulating film 300 for the poly Si-Al wiring is formed; the unevenness is formed on the film 300 surface. The wide Al power supply wiring 400 is arranged on the unevenness, and coated with a PSG protecting film 500 for preventing the damage of IC and protecting the IC from contamination caused by Na ions and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) This invention involves forming an interlayer insulating film on a semiconductor substrate for IC, and using this as a base! The present invention relates to a semiconductor device equipped with a power source.

(Prior Art) An example of a semiconductor device in which a conventional Al power source is wired is as shown in FIG. In this figure, 10
0 is a first conductivity type semiconductor substrate for IC, 200 is a field oxide film (LOGO) formed on this semiconductor substrate 100.
8), on this oxide film 200, poly Si
The interlayer insulating film 300 of the -A and g wirings is formed flat. On this flat interlayer insulating film 300, a wide Al power supply wiring 400 is provided. Furthermore, this A
A PSG protective film 500 is formed on the power supply wiring 400 to prevent damage to the IC and to protect the IC from being contaminated by Na ions or the like.

(Problem to be Solved by the Invention) However, in a conventional semiconductor device, a wide Al power supply wiring 4 is formed using a flat interlayer insulating film 300 as a base surface.
00 is laid down, a PSG protective film 500 is deposited thereon, and then molded. For this reason, as shown in FIG. 6, stress is applied to the Al power supply wiring 400 due to the molding, and this leads to! The power supply wiring 400 is bent. As a result, there was a problem in that cracks were generated in the PSG protective film 500 due to the bending deformation of the ends of the A and e power supply wirings 400, reducing reliability.

This invention was made by focusing on the above-mentioned problems.
The purpose is to provide a semiconductor device that can prevent cracks from occurring in the PSG protective film.

(Means for Solving the Problems) In order to achieve the above objects, the present invention forms a field oxide film on a first conductivity type semiconductor substrate, and forms a poly S t -A,g wiring thereon. A semiconductor device in which an interlayer insulating film is formed, and an Al power supply wiring is provided using this interlayer insulating film as a base, is characterized in that irregularities are formed on the surface of the interlayer insulating film.

(Function) In this invention, Al! , irregularities are formed on the surface of the interlayer insulating film that serves as the base for the power supply wiring. Therefore, even if stress is applied to the Al power supply wiring during molding, this stress is quickly dispersed in multiple directions at the uneven portions of the interlayer insulating film, and the Al! , stress will not be concentrated at the end of the power supply wiring. Therefore, since no bending deformation due to stress occurs at the end of the Al power supply wiring, Ai! , it is possible to prevent cracks from occurring in the PSG protective film from the ends of the power supply wiring.

(Example) The present invention will be explained below based on the drawings.

FIG. 1 is a sectional view of a semiconductor device showing one embodiment of the present invention.

First, to explain the configuration, first conductivity type semiconductor substrate 1 for IC
A field oxide film (LOGO8) 200 is formed on 00, and a diffusion region 601 is formed finely. Then, an interlayer insulating film 300 of poly Si-A and g wiring is formed on this. This interlayer insulating film 300 has an uneven surface, and a wide Al power supply wiring 400 is laid thereon. Furthermore, as shown in Figure 2, there is a function to prevent damage to the IC.
In addition, a PSG protective film 500 is coated to protect the IC from contamination by Na ions and the like.

Next, an example of a manufacturing process for forming irregularities in an interlayer insulating film, which is a base for Al power supply wiring, will be described with reference to FIGS. 3(a) to 3(e).

(a) First, a nitride film (S i 3 N 4 film) 1 for forming a field region for insulating isolation between elements.
000 is formed on the semiconductor substrate 100 (FIG. 1(a)).
).

(b) Next, while using this nitride film 1000 as a protective film to prevent oxidation of the element region, the semiconductor substrate 100 is
An anti-inversion layer 221 (p+ field, n+ field) is deposited on the field region of the field oxide film 200.
((b)) (C) Then, an interlayer insulating film (PSG film) of a required thickness is formed on the field oxide film 200 so that the poly-Si wiring of the semiconductor substrate 100 and the Al2 power supply wiring 400 can be separated. 300 is deposited using an atmospheric pressure CVD apparatus (FIG. 3(C)).

(d) Further, Al is deposited and patterned on this interlayer insulating film 300 to form a wide Al power supply wiring 400 (FIG. 4(d)).

(e) Finally, in order to prevent damage to the Al power supply wiring 400 and to protect the IC from contamination by Na ions, etc., a PSG protective film 50 is placed on the Al power supply wiring 400.
0 is formed ((e) in the same figure).

Next, the above Ai! Another example of the manufacturing process for forming irregularities on the base for power supply wiring will be explained with reference to FIGS. 4(a) to 4(e).

(a) First, a field oxide film (LOCO8) 200 is formed by depositing an anti-inversion layer (p+ field, n+ field) on the field region of the semiconductor substrate 100 (FIG. 2(a)).

(b) Next, n+ polycrystalline silicon is patterned on this to form a poly-Si wiring 600 (see FIG.
b)).

(c) After this, in order to separate the poly-Si wiring 600 and the Al power supply wiring 400, an interlayer insulating film (PS
G film) 300 is deposited using an atmospheric pressure CVD apparatus (see figure (
C)).

(d) Further, Al is deposited and patterned on this interlayer insulating film 300 to form a wide Al power supply wiring 400 (FIG. 4(d)).

(e) Finally, in order to prevent damage to the Al power supply wiring 400 and protect the IC from contamination by Na ions, etc., a PSG protective film 50 is placed on the A poor power supply wiring 400.
0 is formed ((e) in the same figure).

Next, to explain the operation of this embodiment, the PSG protective film 5
When molding 00, stress acts on the Al power supply wiring 400. However, in this example, since the uneven pattern is formed on the base of the Al power supply wiring 400, that is, on the surface of the interlayer insulating film 300, the vertical stress on the Al power supply wiring 400 is dispersed in multiple directions. That is, as shown in FIG. 2, the middle portion of the Al power supply wiring 400 is slightly bent due to the force F of the mold, but in this case, the force is quickly dispersed in the uneven portion of the base, so that the Al power supply wiring 400 is bent slightly. No local stress concentration occurs at the ends.

Therefore, excessive horns are not intensively added to the PSG protective film 500, and cracks are effectively prevented from occurring.

(Effect of the invention) As explained above, according to this invention, a wide A
, g Due to the unevenness formed on the base surface to which the power supply wiring is attached, it is damaged by the mold! Even if stress is applied to the power supply wiring,
This stress is not concentrated at the end of the Al power supply wiring (but is dispersed in many directions in the uneven portion of the base, and as a result,
i! , it is possible to reliably prevent cracks from occurring from the ends of the power supply wiring toward the PSG protective film.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a semiconductor device showing an embodiment of the present invention, FIG. 2 is a detailed view of A and C power supply wiring portions showing stress distribution, and FIGS. 3(a) to (e) are views of the present invention. 4(a) to 4(e) are process diagrams sequentially showing other manufacturing examples of the present invention, FIG. 5 is a sectional view of a semiconductor device showing a conventional example, and FIG. FIG. 2 is a cross-sectional view of a conventional device illustrating locations where cracks occur. 100...Semiconductor substrate 200...Field oxide film 300...Interlayer insulating film 400...Al! , power supply wiring 500...PSG protective film 600...poly-Si wiring 1000...nitride film

Claims (1)

[Claims] 1. A field oxide film is formed on a first conductivity type semiconductor substrate, and an interlayer insulating film of poly-Si-Al wiring is formed thereon, and an Al power supply wiring is formed using this interlayer insulating film as a base. What is claimed is: 1. A semiconductor device comprising: a semiconductor device comprising: a surface of the interlayer insulating film having irregularities formed therein;