Appeal No. 2006-1181
Application No. 10/393,718
Therefore, contrary to Appellants’ assertion that Wristers
does not teach or suggest an isolation layer having a
“predetermined amount of nitrogen” (reply brief, page 2), we
observe that the Examiner has properly relied on Wristers for
incorporating nitrogen in the gate dielectric layer for
increasing the threshold voltage level (col. 3, lines 4-7 and 22-
39). Wristers further describes that a sufficient concentration
of nitrogen in the isolation layer blocks the penetration of
boron atoms and prevents hot electrons from becoming trapped in
the isolation layer (col. 8, lines 54-65).
We also find that the claimed invention does not require a
specific amount of nitrogen or any of the nitrogen concentration
profiles depicted in Appellants’ figure 8 (brief, page 8). To
the extent claimed, Wristers describes how boron atom penetration
in the absence of nitrogen lowers the threshold voltage (col. 3,
lines 4-7) whereas a sufficient concentration of nitrogen blocks
boron atoms in the isolation layer preventing the decrease in the
threshold voltage (col. 8, lines 59-65).
Based on the presented arguments, the weight of evidence in support of each
side and our findings above, we find the Examiner’s case of prima facie obviousness to
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