JPS63164344A - Semiconductor device - Google Patents

Abstract

PURPOSE:To inhibit the generation of voids in an electrode wiring, and to improve reliability by forming an insulating protective film having compressive stress, covering the side section of the electrode wiring and shaping an insulating protective film having tensile stress to coat an upper section. CONSTITUTION:A first silicon oxide film 11 having compressive stress is formed so as to coat an Al wiring 5 through a plasma CVD method or a sputtering method, and a photo-resist agent 5 is applied onto the first silicon oxide film 11 after the formation of the oxide film 11. The photo-resist agent 15 on the upper section of the Al wiring 5 and the first silicon oxide film 11 are removed through a reactive ion etching method, the photo-resist agent 15 left without being removed is gotten rid of, and a second silicon oxide film 13 having tensile stress is shaped onto the Al wiring 5 through the plasma CVD method, a low- pressure CVD method or a normal-pressure CVD method. Only compressive force works on the Al wiring 5, and the generation of voids due to stress migration is prevented.

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) This invention provides insulation protection S! The present invention relates to a semiconductor device with improved reliability of electrode wiring covered with a film.

(Prior Art) In recent years, as semiconductor devices have become highly integrated and miniaturized, the width of electrode wiring, such as aluminum (AΩ) wiring, has become significantly narrower. As described above, when the All wiring width becomes narrow, defects due to so-called electromigration, which is conventionally known, occur. Furthermore, recently r has been caused by AΩ from the periphery of the AΩ wiring, which is called stress migration.
Defects caused by stress acting on Ω wiring are beginning to attract attention. This stress migration will be explained below using FIGS. 3 and 4.

FIGS. 3 and 4 are sectional views of essential parts of a semiconductor device in which the A9 wiring is covered with an insulating protective film. In both figures, a Δ crossing line 5 is formed on the insulating film 3 on the C1 semiconductor substrate 1. This Ω wiring 5 is coated with C V D (chemical
The insulating protective film 7 is formed by a vapor deposition method.

This insulation protection I8!7 may have compressive stress or tensile stress depending on the CVD method used. FIG. 3 shows the case where the insulating protective film 7 has compressive stress, and FIG. 4 shows the case where the insulating protective film 7 has tensile stress.

In FIG. 3, when the insulating protective film 7 has compressive stress, the insulating film i1 film 7 formed on the top of the AC wiring 5 acts as a tensile force on the All wiring 5, and the AΩ wiring I125 The insulating film Ig17 formed on the side portion acts on the AΩ wiring 5 as a compressive force.

On the other hand, in FIG. 4, when the insulating protective film 7 has tensile stress, the insulating protective film 7 formed on the upper part of the A] wiring 5 acts as a compressive force on the wiring 5, and
The insulating protective film 7 formed on the side of the wiring 5 is connected to the A1 wiring 5.
This will act as a tensile force on the

In this way, even if the insulation protection FI 7 formed to cover the An wiring 5 has compressive stress as shown in FIG. 3, it also has tensile stress as shown in FIG. Even if the insulating film ff1g17 is An
A tensile force acts on the wiring 5 at the portion indicated by the dotted line, and this tensile force causes stress migration.

(Problems to be Solved by the Invention) As explained above, the stress inherent in the insulating protective film 7 covering the All wiring 5 acts as a tensile force on the AQ wiring 5, causing stress migration to the A9 wiring 5. cause. Therefore, due to this stress migration, voids (cracks) 9 are generated in the AΩ wiring 5, as shown in FIG. 5A and FIG. And when this void 9 grows, △
There was a problem in that the Ω wiring 5 was disconnected, leading to an open failure in the An wiring 5.

The present invention has been made in view of the above, and its purpose is to suppress the generation of voids in the electrode wiring by relieving the tensile force acting on the electrode wiring. An object of the present invention is to provide a semiconductor device with improved reliability.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides an insulating protection having compressive stress so as to cover the sides of electrode wiring formed on a semiconductor substrate. A film is formed, and an insulating film protective film having tensile stress is formed to cover the upper part of the electrode wiring.

(Function) In the semiconductor device of the present invention, an insulating protective film having compressive stress is formed to cover the sides of the electrode wiring, and a tensile stress protecting film is formed to cover the upper part of the electrode wiring. The insulating protective film has a compressive force on the electrode wiring.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a main part of a semiconductor device according to an embodiment of the present invention. Components with the same reference numerals as in FIGS. 3 and 4 have the same functions, and their explanation will be omitted.

In FIG. 1, an insulation 113 is formed on the semiconductor substrate 1, and an A9 wiring 5 is formed on the insulation 1113. Further, a first silicon oxide l1111 having compressive stress is formed between the AΩ wirings 5 on the insulation 113 as an insulating protective film covering the A9 wirings 5. Further, a second silicon oxide film 13 having tensile stress is formed as an insulating protective film covering the An wiring 5 over the A1 wiring 3.

Next, an example of a manufacturing process for a semiconductor device having such a structure will be described with reference to FIGS. 2(A) to 2(E).

First, the insulating film 3 is formed on the semiconductor substrate 1, and then the A9 wiring 5 is formed on the insulating film 3 (FIG. 2(A)).

Next, the first silicon oxide film 11 having compressive stress is
AΩ wiring 5 by plasma CVD method or sputtering method
After the formation, the first silicon oxide l! Apply photoresist agent 15 on top of 11 (second
Figure (B)).

After applying the photoresist agent 15, the photoresist agent 15 and the first silicon oxide film 11 on the upper part of the All wiring 5 are applied.
is removed by etching using a reactive ion etching method (FIG. 2(C)).

Next, the remaining photoresist agent 1 that was not removed in the above step is
5 (Figure 2 (D)).

After removing all the photoresist agent 15, the second silicon oxide 1113 having tensile stress is removed by plasma Cv
AΩ by D method, low pressure CVD method or normal pressure CVD method.
It is formed on the wiring 5 (FIG. 2(E)).

Through this manufacturing process, as shown in FIG. 1, the first silicon oxide film 11, which acts as an insulating protective film covering the AQ wiring 5, is formed between the A9 wirings 5, which absorbs compressive stress, and reduces tensile stress. If the second silicon oxide 1113 having the above structure is formed on top of the AΩ wiring 5, only compressive force will act on the AΩ wiring 5.

Therefore, the tensile force applied to the Aρ wiring 5 can be suppressed.

In addition, in this embodiment, AQ distribution I! ! Although silicon oxide films 11 and 13 are used as the insulating protective film in No. 5, the present invention is not limited thereto, and any insulating film having compressive stress and tensile stress may be used.

Furthermore, such an arrangement structure of the insulating protective film can also be applied to multilayer wiring of Aρ, and when applied to multilayer wiring, the formation process for obtaining the above arrangement structure may be performed by stacking layers. Furthermore, it is extremely convenient because it includes a planarization process to prevent wire breakage due to level differences in the wiring.

[Effects of the Invention] As explained above, according to the present invention, an insulating protective film having compressive stress is formed so as to cover the sides of the electrode wiring, and an insulating protective film having tensile stress is formed to cover the sides of the electrode wiring. Since it is formed to cover the upper part of the wiring, the force acting on the electrode wiring from the insulating protective film becomes a compressive force, making it possible to suppress the generation of voids in the electrode wiring. As a result, a semiconductor device with improved reliability of electrode wiring can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a semiconductor device according to an embodiment of the present invention, FIGS. 2(A) to 2(E) are sectional views showing the manufacturing process of FIG. 1, and FIGS. 4 is a cross-sectional view of a main part of a conventional semiconductor device having electrode wiring covered with an insulating protective film, FIG. 5(A) is a plan view showing voids in the electrode wiring, and FIG. (This is a cross-sectional view of A>. (Explanation of symbols representing main parts of the drawing) 5...AΩ
wiring

Claims (1)

[Claims] An insulating protective film having compressive stress is formed to cover the sides of the electrode wiring formed on the semiconductor substrate, and an insulating protective film having tensile stress is formed to cover the upper part of the electrode wiring. Characteristic semiconductor devices.