Appeal No. 2002-0974
Application 09/332,745
depositing an epitaxial layer onto the surface of a silicon
wafer; (2) heating the wafer to a temperature of at least 1175°C
during epitaxial layer deposition, after epitaxial layer
deposition or during and after epitaxial layer deposition; and ,
(3) cooling the heated wafer from the second step for a period of
time and at a rate of at least about 10°C per second. The third
step is conducted while: the temperature of the wafer is greater
than about 1000°C; and, during cooling, the wafer is not in
contact with a susceptor. Each of the three process steps of
deposition, heating and cooling are conducted in the same reactor
chamber.
The epitaxial layer deposited on the surface of the silicon
wafer is not set forth in claim 1. While appellants disclose that
the layer deposited is epitaxial silicon, claim 1 is not so
limited and, therefore, embraces depositing any epitaxial layer.
The cooling step requires a cooling rate of at least 10°C per
second while the temperature of the wafer is greater than 1000°C.
Thus, the claimed process includes cooling the wafer while it is
above 1000°C at the specified rate and after the temperature
falls below 1000°C cooling at any rate or not cooling at all.
According to appellants' disclosure, the cooling may be effected
by simply turning off the heat source for the reactor.
5
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: November 3, 2007