Appeal 2006-2769
Application 09/846,980
etchant such as buffered hydrogen fluoride (col. 1, In [sic, ll.]
15-30).
It would have been obvious to a person of ordinary skill
in the art at the time of the invention to modify Bour with
Koike's electron beam irradiation because it would have
produced p-type conductive semiconductors with low
resistivities.
See Br. 4-7 and Reply Br. 1-4. The Appellants only argue that the prior art
references would not have suggested “heating said p-type layer to a third
temperature greater than the second temperature and less than 625o C. to
remove hydrogen from said p-type layer…” recited in claims 1 and 31. See
Id. The dispositive question is, therefore, whether one of ordinary skill in
the art would have been led to anneal, after cooling, a p-type III-V nitride
layer at a temperature higher than a cooling temperature, but less than
625oC. within the meaning of 35 U.S.C. § 103. On this record, we answer
this question in the affirmative.
As recognized by the Examiner (Answer 4-5), Bour teaches (col. 6, ll.
46-58):
Upon attainment of this temperature [around 600o C. to 800o
C.], the N outdiffusion preventor gas, NH3, is switched out of
reactor 10, as shown in step 35 in FIG. 6, and acceptor
activation is performed either as the reactor is further cooled
down or at a temperature maintained for a given period of time
as indicated at step 36. As an example, if the temperature is
maintained at 600o C., then the time period for activation may
be tens of minutes, such as, for example, between about 20 to
about 40 minutes. This anneal process indicated in FIG. 3
wherein, during the cooldown of reactor 10, a flow of molecular
N, N2, is maintained in the reactor as acceptor activation is
carried out in the matter as just described.
10
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