Appeal No. 1997-3916
Application No. 08/429,650
Appellants assert (brief, page 10), that there is no description or teaching in the reference of an anti-
punchthrough region narrower than the gate electrode. Appellants argue (brief, page 11) that:
On reviewing the Kubo patent, however, one of ordinary skill in the art finds no clear
teachings regarding the size of an anti-punchthrough region. Rather, one of ordinary skill
finds a jumble of poorly drawn, schematic figures that convey no clear teachings as to the
size of an anti-punchthrough region. One of ordinary skill, upon finding no clear teachings
related to the size of buried anti-punchthrough regions in the figures of the Kubo patent
could continue to the text of the Kubo patent and find a complete lack of teachings as to
the relative size of the anti-punchthrough region and the gate in the specification of the
Kubo patent.
Thus, the issue before us is whether Kubo teaches or suggests forming a buried anti-punchthrough
implant channel that is narrower than the gate electrode. Based upon the opposing arguments found in the
brief and the answer, we find this disputed issue of fact to be close; but on the balance, we find that Kubo
does not teach or suggest forming a buried anti-punchthrough layer that is narrower than the gate
electrode, for the following reasons.
From our review of Kubo, we agree with the examiner that figures 1 and 10 of Kubo, as well as
figures 2A, 2B, 12A-12D and 13-15 appear to illustrate buried layer (1C) to be narrower than the
electrode (3); whereas figures 3-9, as well as figure 11 appear to illustrate the buried layer (1C) to be
wider than electrode (3). However, we are in agreement with appellants (brief, pages 11 and 12) that the
figures of Kubo are too variable and schematic in nature, and provide no clear teaching as to the size of the
buried anti-punchthrough implant channel. For example, as illustrated in the drawings of Kubo, measuring
the size of various elements found in the drawings, we find that in figure 1, buried layer (1C) is 10 mm
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