Appeal No. 95-3455
Application 07/945,902
lines 8 through 27. At column 9, lines 5 through 16, an
example of depositing tungsten silicide from a mixture of
dichlorosilane and tungsten hexafluoride is described. A
rapid, efficient deposition is obtained. See also claim 2
which claims the use of tungsten hexafluoride and
dichlorosilane.
Price'474 discloses the manufacture of semiconductor
devices having a silicide/silicon bond (column 1, lines 5
through 7). Improved metal gate systems for MOS devices are
achieved by depositing an intermediate amorphous silicon layer
on polycrystalline silicon with a silicide such as tungsten
silicide deposited over the amorphous silicon (column 1, line
65 through column 2, line 12). To deposit tungsten silicide,
tungsten hexafluoride and dichlorosilane are utilized (column
3, lines 44 through 49).
Koyama et al. disclose depositing tungsten silicide by
reducing tungsten hexafluoride with dichlorosilane. The film
is deposited at higher temperatures than when using silane.
The resultant silicide has lower fluorine content which lowers
stress variation during thermal treatment. The properties of
the silicide so-produced make the polycide desirable for use
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