Appeal No. 2006-1797
Application No. 09/866,319
collector 4 through the base region 80, 81, 82 of the
transistor.
Appellants submit that a broad shallow profile of the
SIC region results from the combination of the light (high-
diffusivity) dopant ion and high-energy implant necessary to
implant SIC dopants through the base region 80, 81, 82, as
disclosed in Marty, et al. Subsequent spreading of the
highly mobile light ion during high temperature processing
forms a broad shallow implant profile, as opposed to
Appellants’ n-type region having a narrow vertical width
(W). Appellants further submit that a tail of n-type
dopants is necessarily present in the prior art transistor
extending from the SIC region into the base 80, 81, 82.
Although not depicted in the drawings provided in Marty et
al., the tail of n-type dopants is present, since the SIC
region is formed by implanting the high-diffusivity n-type
dopants through the base 80, 81, 82 into the collector 4.
Therefore, since the SIC region disclosed in Marty, et al.
has a broad shallow dopant profile that necessarily includes
a tail of n-type dopants contacting the base 80, 81, 82,
Marty, et al. fail to disclose an n-type dopant region
having a vertical width sufficiently narrow to avoid
lowering collector-base breakdown voltage when the device is
forward biased.
To determine whether claim 45 is anticipated, we must first
determine the scope of the claim. We note that claim 45 reads in
part as follows:
“[F]orming a n-type dopant region within said collector
region so as to be in contact with said deep collector, said
n-type dopant region having a vertical width sufficiently
narrow to avoid lowering collector-base breakdown voltage
and a dopant concentration sufficiently high to restrict
base widening when a base-emitter junction is forwarded
(sic) biased.”
At page 8, lines 3-19, Appellants’ specification states:
In accordance with the present invention, the n-type dopant
region has a vertical width, W, that is less than about 2000
Å and a peak concentration that is greater than a peak
concentration of said collector region. Thus, n-type dopant
8
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