Appeal No. 1997-3916
Application No. 08/429,650
wide. The same element (1C) in figure 3 is 14 mm wide. The same element (1C) in figure 4 is 18 mm
wide and in figure 7, element (1C) is 20 mm wide. Additionally, in figure 7, the height of element (1C) is
4.5 mm. In figure 8, the same element is 6 mm in height. Moreover, in figure 1, drain wiring electrode (7)
is 17.5 mm wide, whereas source wiring electrode (8) is illustrated as 20 mm wide. In figure 3, both the
source drain wiring electrode (7) and the source wiring electrode 8 are 17.5 mm wide. IN contrast, in
figure 10, the drain wiring electrode (7)
is 19 mm wide whereas the source wiring electrode (8) is 21 mm wide. We find no reference in the
specification of Kubo to indicate that any of these elements are intended to be of different sizes.
With respect to the issues of whether the different sizes of buried elements (1C) of Kubo suggests
making the buried elements (1C) narrower than the gate electrode, from our analysis of Kubo, we find that
in view of Kubo's illustrations depicting different elements to be different sizes; along with the fact that
Kubo does not recognize the problem of preventing punchthrough by reducing the size of the buried
implant that Kubo does not suggest forming a buried layer (1C) narrower than the gate electrode (3). We
are in agreement with appellants (brief, pages 12 and 13) that in reviewing Kubo's teachings regarding the
formation of the buried layer (1C) that:
Nowhere in the Kubo patent is there further description of the photoresist mask used to
define buried region 1C. Thus, there is too little information in the specification of the
Kubo patent to constitute a teaching as to the relative size of the anti-punchthrough regions
of the Kubo patent.
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