Appeal No. 2003-2107
Application No. 09/429,283
affects it. Therefore, though the amount of dopant might be a
result effective variable, as asserted by the examiner, Gardner's
teachings are insufficient to reach that conclusion.
The examiner's synopsis of Chou is partially correct. That
is, Chou teaches nitrogen implantation for PMOSFETs and shows how
different dosages of nitrogen affect flatband voltage shift,
oxide reliability, sheet resistance, and poly depletion effects
in PMOSFETs. However, Chou does not teach nitrogen implantation
for n-type MOSFETs. Instead, Chou states (second column on page
176) that "N+ poly NMOSFET gm and threshold voltage are not
affected by nitrogen implant." Accordingly, although Chou
suggests that nitrogen concentration is a result effective
variable for PMOSFETs, Chou fails to suggest implanting nitrogen
in NMOSFETs at a concentration different from that used for the
PMOSFETs. Further, Chou does not disclose implanting any other
impurities in both transistors.
Kuroi shows (in Figure 1) a PMOSFET and an NMOSFET, each
with nitrogen implanted gates. As recognized by the examiner
(Answer, page 5), Kuroi graphs the effects of different nitrogen
concentrations for PMOSFETs and NMOSFETs. However, Kuroi (on
page 772) implants the nitrogen ions into the polysilicon film
for both MOSFETs at the same time, thereby suggesting the same
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