JPH05129298A - Method of manufacturing semiconductor device - Google Patents

Abstract

PURPOSE:To contrive to improve electromigration resistance of an Al wiring by a method wherein a substrate is set within a scope of a specific temperature and respectively performed sputtering by using an Al film-forming material containing the specific amount of Si and Cu. CONSTITUTION:An Al film is formed by sputtering on a substrate. In this embodiment, the substrate is set at a temperature of 150 deg.C to 220 deg.C and performed sputtering by using an Al film-forming material containing Si with a weight ratio of 2.0% or less and Cu with a weight ratio of 1.0% or less, Thus, the Al film in which an Al (111) orientation is high and an Al (200) orientation is substantially zero can be formed, and accordingly electromigration resistance of the Al wiring is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly, it is used for forming aluminum wiring (Al wiring) on a semiconductor chip.

[0002]

2. Description of the Related Art As an Al film formation for forming an Al wiring,
Besides the vacuum vapor deposition method, the sputtering method is known.
The Al wiring formed by such a film forming method is required to have high electromigration resistance and stress migration resistance.

[0003]

For this reason, various improvements have been made in the past, but with the miniaturization of integrated circuits,
It cannot be said that it is still sufficient under the thinning of the 1-wiring, and under the demand for longer life of the semiconductor device, realization of more excellent durability is an issue. By the way, the electromigration resistance of the Al wiring depends on the orientation of the Al film, as described in the following document "EFFECT OF.
TEXTURE AND GRAlN STRUCTU
RE ~ ", 75 (1981) P.P. 253-259,
ThinSolid Films. ].
Based on this, the present inventor has completed the present invention as a result of examining the improvement of the electromigration resistance of the Al wiring by the sputtering film forming method.

[0004]

A method of manufacturing a semiconductor device according to the present invention is a method of forming an aluminum film on a substrate by sputtering, wherein the substrate is set at a temperature of 150 ° C. or higher and 220 ° C. or lower. The sputtering is performed using an aluminum film forming material containing silicon in a weight ratio of 2.0% or less and copper in a weight ratio of 1.0% or less.

[0005]

According to the present invention, an Al film having high Al (111) orientation and almost zero Al (200) orientation can be formed, and therefore, electromigration resistance of Al wiring can be improved. ..

[0006]

EXAMPLES Al wiring is generally formed as follows. First, a substrate such as a silicon wafer is prepared and a silicon oxide film is formed. Next, this substrate is set in a sputtering apparatus, and an Al wiring material is formed by sputtering. Then, a resist pattern is formed on the Al film,
By etching the Al film using this as a mask, an Al wiring having a desired pattern can be obtained.

The wiring material in the present invention contains Al as a main component and contains a trace amount of Si and a trace amount of Cu. Here, Si is preferably 2.0% or less by weight ratio, and Cu is 1.0% by weight ratio.
% Or less is desirable. The substrate temperature during sputtering in the present invention is preferably 150 ° C to 220 ° C. This is because if the temperature is lower than 150 ° C., the degree of Al (111) orientation does not become high, and the degree of Al (200) orientation cannot be suppressed low. On the other hand, if the temperature exceeds 220 ° C, Al
Although the degree of (200) orientation can be lowered, Al (111)
This is because the degree of orientation cannot be increased.

Next, a concrete example by the present inventor will be described. First, as a sample, S of 0.6 μm on the surface
A silicon substrate having an iO ₂ film formed by thermal oxidation was prepared.
Then, under the following requirements, a 1 μm Al film was formed by sputtering. First, for wiring materials, 1% Si
And Al containing 0.5% Cu were used, and a magnetron sputtering apparatus was used as the sputtering film forming apparatus. The DC sputter power is 6 [KW] and Ar is
Flow rate is 50 [SCCM] and the sputter pressure is 0.5
[Pa]. The degree of Al orientation is indicated by X-ray diffraction intensity. The results are shown in FIG. Substrate temperature 150 ~
It was confirmed that by setting the temperature to 220 ° C., the Al (200) orientation was extinguished while the Al (111) orientation was increased.

Next, 1.0% Si and 0.5 formed at respective substrate temperatures of 120 ° C., 186 ° C. and 240 ° C.
% Cu is formed on the wiring by a normal patterning and etching method, and then PSG (Phospho Silicate Glass) is formed by a room temperature CVD method.
A film having a thickness of 0.6 μm was formed and an electromigration test was conducted. At this time, the wiring width is 2.4 μm, the wiring length is 1000 μm, the test condition is 175 ° C., and the current density is 1E6A /
cm ² . The results are shown in FIG. Al (11
1) It was confirmed that a substrate heating temperature of 186 ° C. having a high orientation strength has a long life. Also, 50% failure time (MTF)
Comparing with 1300Hr at 120 ℃, 25 at 240 ℃
Although it was 90 hr, it was 5000 hr at 186 ° C.

Therefore, based on the above results, the substrate temperature is set to 15
It was confirmed that by setting the temperature to 0 to 220 ° C., the Al (200) orientation can be eliminated while increasing the Al (111) orientation, and the electromigration resistance can be improved.

[0011]

As described above in detail, according to the present invention,
An Al film having a high Al (111) orientation and a substantially zero Al (200) orientation can be formed, and therefore the electromigration resistance of the Al wiring can be improved. Therefore, the reliability of the semiconductor device can be improved and the life of the semiconductor device can be extended.

[Brief description of drawings]

FIG. 1 is a diagram showing a result of an example of the present invention.

FIG. 2 is a diagram showing a result of an electromigration test of an example of the present invention.

Claims (1)

[Claims] 1. A method of manufacturing a semiconductor device in which an aluminum film is formed on a substrate by sputtering, wherein the substrate is set to a temperature of 150 ° C. or higher and 220 ° C. or lower, and a weight ratio of 2.0% or lower. A method for manufacturing a semiconductor device, comprising: sputtering using an aluminum film forming material containing silicon and copper in a weight ratio of 1.0% or less.