Appeal No. 95-3438
Application No. 08/033,656
silicon semiconductor wafer) by reacting ammonia with a silane
compound in a low pressure chemical vapor deposition (LPCVD)
chamber wherein, inter alia, the pressure is adjusted to from
about 5 to 100 Torr. Claim 1 is representative and is
reproduced below:
1. A method of depositing films of silicon nitride onto
a single substrate in a low pressure chemical vapor deposition
chamber comprising
a) supporting a single substrate in said chamber;
b) adjusting the pressure to from about 5 to about 100
Torr and heating the substrate to a temperature of from about
650 to about 850EC; and
c) passing a precursor gas mixture comprising a silane
gas and ammonia into said chamber,
thereby depositing a film of stoichiometric silicon nitride of
uniform thickness onto said substrate.
As evidence of obviousness, the examiner relies on the
following references:
Chiang 4,395,438 July 26,
1983
Morosanu, “Thin Films by Chemical Vapour Deposition ” Thin
Films Science and Technology, p. 48 (1990)
Schuegraf, “Handbook of Thin-Film Deposition Processes and
Techniques” Noyes Publication, pp. 81 and 86 (1988)
As evidence of nonobviousness, appellants rely on the
2
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