JPS5912010B2 - Manufacturing method of semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device, and particularly to a method of forming wiring therefor.

In the conventional method for forming electrode wiring in semiconductor devices, electrode contact windows are formed in an insulating film such as silicon oxide to correspond to the terminals of active elements and passive elements, and then contact windows made of titanium or platinum are formed. After metal is deposited on the entire surface of the silicon substrate, it is necessary to perform heat treatment to form metal silicide in the contact area of the element, and then to remove the excess contact metal that has not changed to metal silicide by etching. Ta.

Next, metal for wiring is deposited and selectively etched to form electrode wiring. 5. Such conventional techniques not only require the difficult process of etching excess contact metal, but also pose major problems such as performance deterioration and yield reduction due to contamination in this process.

10 An object of the present invention is to provide a method for manufacturing a semiconductor device using a novel method for forming electrode wiring, which improves the above-mentioned drawbacks.

The features of the present invention include the steps of providing an insulating film having an opening on a semiconductor substrate, depositing a first metal on the insulating film and in the opening 15, and forming metal silicide in the opening. step, followed by a step of depositing a second metal on the first metal, and etching the first metal into a desired wiring pattern after diffusing and absorbing the first metal into the second metal. A method of manufacturing a semiconductor device includes steps.

For example, a contact metal is deposited as the first metal on the entire main surface of a single crystal silicon substrate on which an insulating film provided with an electrode contact window is deposited, and metal silicide is applied to the electrode contact window. 25. A method for manufacturing a semiconductor device, which further comprises depositing a wiring metal as a second metal, diffusing and absorbing the contact metal on the insulating film into the wiring metal, and then forming an electrode wiring in a desired shape. It is. According to the present invention, since a metal silicide film is formed by the first metal at the opening 30 of the substrate, so-called alloy spikes in which the second metal becomes alloyed with the substrate can be prevented.

Since patterning by etching is performed after the first metal is diffused and absorbed into the second metal, a metal that is difficult to etch 35 can be used as the first metal. Furthermore, since the first and second metals can be etched at once, the manufacturing process is simplified, contamination due to etching is reduced, and the yield of semiconductor devices is improved. Next, the present invention will be explained in detail with reference to the drawings.

Figures a to e are process diagrams showing a method for manufacturing a semiconductor device according to an embodiment of the present invention. As shown in FIG.
Contact metals such as chromium and molybdenum are vapor-deposited 5
A metal film 4 of 0 to 200 A is formed.

The contact metal may be any of the metals listed above, or a combination of two or more metals selected from these metal groups. Next 350-6
When heat treatment is performed at a temperature of 50° C., metal silicide 5 is formed in the contact window portion as shown in FIG. b. A wiring metal layer 6, such as aluminum, is then applied to a thickness of 1 to 3 .mu.m (FIG. c).

Next, heat treatment is performed at a temperature of 200 to 600° C. for 1 to 10 minutes to diffuse and absorb the contact metal film 4, which has not changed into metal silicide, into the wiring metal layer 6 (FIG. d).

Finally, selective etching is performed to obtain the desired shape of the electrode wiring pattern (Figure e).

It is conceivable that the heat treatment for forming metal silicide and the heat treatment for diffusing and absorbing the contact metal into the wiring metal layer 6 can be performed in a single heat treatment. 6, it is necessary to form metal silicide before the alloy spike is formed. Therefore, the thickness of the contact metal film 4 and the temperature of the heat treatment,
This is not preferable because it requires sufficient time management.

As is clear from the above description, according to the method for manufacturing a semiconductor device of the present invention, contact metal, which is difficult to etch, is diffused and absorbed into wiring metal, and then etching is performed to form an electrode wiring pattern. This not only simplifies and simplifies the etching process, but also ensures that the contact metal film is not deposited, the heat treatment is performed to convert the metal into a metal silicide, the wiring metal is deposited, and the wiring metal does not change into metal silicide. The process of diffusing and absorbing the contact metal can be performed within the vapor deposition apparatus, and the problems of performance deterioration and yield reduction due to contamination can be significantly improved. Note that although the wiring metal absorbs a small amount of the contact metal, no phenomenon in which the electrical resistance increases due to this is observed.

[Brief explanation of the drawing]

Figures a to e are cross-sectional views in the order of steps, each showing a method for manufacturing a semiconductor device according to an embodiment of the present invention. In the figure, 1... single crystal silicon substrate, 2...
- Insulating film, 3... window for contact, 4... metal film for contact, 5... metal silicide, 6... metal layer for wiring.

Claims (1)

[Claims] 1. A step of providing an insulating film having an opening on a semiconductor substrate, a step of depositing a first metal on the insulating film and in the opening, and a step of forming metal silicide on the semiconductor substrate in the area of the opening. Then, a step of depositing a second metal on the first metal, and forming an electrode wiring in a desired shape by etching after diffusing and absorbing the first metal into the second metal. A method for manufacturing a semiconductor device, comprising the steps of: