Appeal No. 2003-2107
Application No. 09/429,283
n-type gates," and Kuroi discloses "the effects of different
nitrogen concentrations and dopant concentrations in the gate of
a MOSFET for both p-type and n-type gates thus establishing
concentrations of dopant and nitrogen together to be a result
effective variable." Although the examiner includes Sze in the
statement of the rejection, we find no explanation as to why the
examiner included Sze.
Rather than try to decipher the examiner's reasoning for
combining the references, we will analyze each reference for its
teachings and combinability with the other references applied by
the examiner. We begin with Chishima.
As indicated by the examiner (Answer, page 5), Chishima
teaches implanting nitrogen in the p-channel area. However,
Chishima also explains (translation, page 4) that for an n-
channel MOSFET, nitrogen doping "leads to an undesired increase
in the gate capacitance. Consequently, doping of nitrogen N in
the n-channel MOSFET region should be avoided" (emphasis ours).
We note that claim 14 encompasses impurities other than nitrogen;
however, nitrogen is the only impurity discussed by Chishima with
regard to both transistors. Accordingly, Chishima teaches away
from the claimed invention. Further, the Federal Circuit has
held that "a proposed modification [is] inappropriate for an
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