Appeal No. 1997-3512 Page 5
Application No. 08/482,034
same. The examiner argues (answer, pages 3 and 4) that the
“p++” and “p” doping ranges of the two base layers define the
whole range of well known doping concentrations, and that any
point of doping concentration between these upper and lower
bounds is therefore approximately the same doping
concentration.
From our review of Gaw, we are not in agreement with the
examiner’s characterization of the doping concentrations of
Gaw’s base layers 12 and 13. We find that Gaw does not
reasonably suggest that the two layers have approximately the
same doping concentrations to the extent that they are both
within the vicinity of lower and upper ranges of p and p++.
To the contrary, Gaw is directed to a (page 2, col. 1, lines
6-9) “heterojunction bipolar transistor having a multilayer
base structure, wherein the layer adjacent to the emitter is
more heavily doped than the layer adjacent to the collector.”
Base layer (13) is a “highly doped” p-type layer “p++” in
contrast to base layer (12) which is a “lightly doped” p-type
layer “p.” As further disclosed by Gaw (page 3, col. 4, lines
11-16), “It is believed that current flow is enhanced by the
presence of an accelerating field generated by the wide band
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