Appeal No. 2006-1797
Application No. 09/866,319
region 18 is a narrow, medium doped spike in the doped
collector region of a high-voltage heterojunction bipolar
transistor. The inventive n-type dopant region is heavy
enough however to significantly delay the onset of the Kirk
effect, yet narrow enough to avoid creating a high-electric
field region of sufficient duration to degrade the breakdown
characteristics of the device.
Further, at page 11, lines 8-13, Appellants’ specification
states:
In accordance with the present invention, n-type dopant
region 18 has a width (measured vertically) that is less
than about 2000 Å, and a peak concentration that is greater
than a peak concentration of said collector region. More
preferably, n-type dopant region 18 has a vertical width of
from about 800 to about 1200 Å. Another characteristic of
the inventive dopant region is that it has a doping level,
i.e., concentration, that is lower than that of the base
region.
Thus, the claim does require an n-type dopant region having
a vertical width (W) that is sufficiently narrow to avoid
lowering the collector base breakdown voltage and a dopant
concentration sufficiently high to restrict base widening when
the base junction is forward biased.
Our reviewing court states that: “[W]hile features of an
apparatus may be recited either structurally or functionally,
claims directed to an apparatus must be distinguished from the
prior art in terms of structure rather than function.” In re
Schreiber, 128 F.3d 1473, 1477-78, 44 USPQ2d 1429, 1431-32 (Fed.
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