JPH01130544A - Wiring of semiconductor device - Google Patents

Abstract

PURPOSE:To alleviate the stress caused by the upper and the lower layers of a wiring by a silicon film as well as to prevent the elimination of an aluminum film by a method wherein the wiring is formed in such a manner that a layer of aluminum film is pinched by two silicon film layers. CONSTITUTION:A vapor growth film 2 is formed by patterning on a semiconductor substrate 1, and a wiring 4 of three-layer structure, contacting to the substrate 1, is formed through the intermediary of a contact hole 3. An Si film 5 is formed on the lower layer of wiring 4, and an Al film 6 is formed thereon in such a manner that the hole 3 will be buried by the film 4. Besides, an Si film 7 is formed on the top layer of the wiring 4, a three-layer Al film 6 is formed in such a manner that it is pinched by the two layers of Si films 5 and 7. Then, a PSG film 8 is laminated on the wiring 4. Accordingly, the stress caused by the films 2 and 8 is alleviated by the films 5 and 7 of the wiring 4, and the shifting of the film 6 by said stress is suppressed. As a result, the elimination of the Al film can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to wiring of a semiconductor device that connects semiconductor integrated circuit elements formed on a semiconductor substrate.

[Prior Art] Conventionally, in semiconductor devices, an AJ thin film formed to a predetermined thickness by sputtering aluminum (Aβ) has been used as wiring to electrically connect semiconductor elements. There is.

[Problems to be Solved by the Invention] However, in the wiring of the conventional semiconductor device described above, when a vapor phase growth film is formed as the base of the wiring, a PSG film (containing phosphorus) is used as the upper layer. If a silicon oxide film is formed, there is a problem that the AJ film of the wiring may be locally destroyed due to stress acting from the lower and upper films.

The present invention has been made in view of such problems, and includes:
An object of the present invention is to provide a wiring for a semiconductor device in which disappearance of a wiring-constituting film is avoided.

[Means for Solving the Problems] In the semiconductor device wiring according to the present invention, which connects integrated circuit elements formed on a semiconductor substrate, one of an aluminum film and a silicon film is used. It is characterized by having a three-layer structure in which one layer of the film is sandwiched between two layers of the other film.

[Function] In the present invention, the wiring consists of two layers of aluminum film.
It has a three-layer structure in which two layers of silicon films are sandwiched between each other, or one layer of silicon film is sandwiched between two layers of aluminum films. When an aluminum film is sandwiched between silicon films, the silicon film relieves stress from films disposed above and below the wiring, so the aluminum film does not disappear. On the other hand, when a silicon film is sandwiched between aluminum films, silicon diffuses and precipitates in the grain boundaries of the aluminum film, thereby suppressing migration of the aluminum film and preventing disappearance of the aluminum film.

[Example] Next, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.

A vapor phase growth film 2 is patterned on a semiconductor substrate 1, and a contact hole 3 provided in this vapor growth film 2
A three-layer interconnection 4 is formed so as to be in contact with the semiconductor substrate 1 via.

A Si film 5 is formed on the bottom layer of the wiring 4 by sputtering Si to a thickness of 200 to 400 layers. Note that the contact hole 3 is provided by forming a sputtering Si film 5 on the vapor-phase grown film 2 and then pattern-etching both films.

Then, by sputtering Aβ to a predetermined thickness after forming the Si film 5, an Aρ film 6 is formed to fill the contact hole 3.

Furthermore, as the top layer of the wiring 4, St is 200 to 400.
The Si film 7 is formed by sputtering to a thickness equal to that of the average thickness. In this way, the Aρ film 6 is formed into two layers of S
A three-layer interconnection 4 sandwiched by i-films 5 and 7 is provided.

A PSG film (silicon oxide film containing phosphorus) 8 is laminated on this wiring 4.

In the wiring of a semiconductor device configured in this way, P
The stress from the SG film 8 and the vapor growth film 2 is relaxed by the first and third Si films 5 and 7 of the wiring 4, and the movement of the Al film 6 due to this stress is suppressed. Therefore, disappearance of the AJ film 6 is prevented.

Next, a second embodiment of the present invention will be described based on the sectional view of FIG.

In this embodiment, the structure of the wiring 9 is different from the wiring 4 of the first embodiment. In FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted.

In this wiring 9, the lowest layer Aρ film 10 is formed by sputtering so as to fill the contact hole 3. This Aβ film 10 is approximately 1/1/2 of the predetermined film thickness of the wiring 9.
It has a film thickness of 2. Ajl film 1 film 0 on top, SL 200
By sputtering to a film thickness of 400 to 400 mm,
An S1 film 11 is formed. Then, on the uppermost layer of the wiring 9, an Aρ film 12 having a thickness approximately 1/2 of the predetermined thickness of the wiring 9 is formed by sputtering as well.

In this second embodiment, Si from the second layer Si film 11 of the wiring 9 diffuses through the grain boundaries of the first and third layer AI films 10. It precipitates out.

As a result, even when subjected to stress from the vapor-phase grown film 2 and the PSG film 8, the A and f films 10.12 do not move and are prevented from disappearing.

[Effects of the Invention] As explained above, according to the present invention, the wiring is made of Si film and A
Since it has a three-layer structure with the J film, when the AJ film is sandwiched between the Si films, the Si film alleviates the stress from the upper and lower layers of the wiring, preventing the AJ film from disappearing, and also preventing the AJ film from disappearing.
When the film is sandwiched between A1 films, Si diffuses through the grain boundaries in the A1 film and precipitates, suppressing the movement of the Aβ film and Aρ
Disappearance of the film is prevented. As described above, the present invention has the effect of preventing the disappearance of the A1 film of the wiring, and is extremely useful in manufacturing semiconductor devices.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the invention, and FIG. 2 is a longitudinal sectional view showing a second embodiment of the invention. 1; Semiconductor substrate, 2; Vapor phase growth film, 3; Contact hole, 4.9; Wiring, 5.7.11; Si film, 6, 10.
12; A1 membrane, 8. PSG membrane application applicant Hondenki Co., Ltd.

Claims (3)

[Claims] (1) In semiconductor device wiring that connects integrated circuit elements formed on a semiconductor substrate, a three-layer structure in which one layer of either an aluminum film or a silicon film is sandwiched between two layers of the other film. Wiring for a semiconductor device characterized by having the following. (2) The wiring for a semiconductor device according to claim 1, wherein the one film is an aluminum film. (3) The wiring for a semiconductor device according to claim 1, wherein the one film is a silicon film.