Appeal No. 2005-0323 Page 9
Application No. 09/577,835
bottom of the gate stack to the top. The figure appears to show
the sidewalls extending virtually up to the top of the gate
stack. Although the drawing shows silicide layer 122 extending
slightly above the top of the composite sidewall, we note that
the drawings are not to scale. In addition, the silicide layer
is very thin, perhaps in the range of several hundred angstroms.
We observe the statement in appellants' specification (page 12)
that:
To provide spacers that extend to about the same height
as the resulting stack 10, the nitride spacers 22 can
be over-etched slightly during formation of the spacers
(see FIG. 8). The extent of the over-etching that is
desirable will depend on the amount of the oxide layer
20 that is to be subsequently removed prior to the
source/drain reoxidation. The amount of over-etching
of the nitride spacers 22 can be controlled so that
following removal of part of all of the oxide layer 20
the top of the stack 10 and the top of the nitride
spacers 22 are at about the same height (see FIG. 9).
(Underlining added)
However, although it appears that the sidewalls may extent to the
top of the gate stack, to the extent disclosed by appellants,
because the examiner and appellants have taken the position that
the sidewalls of Gardner do not reach the top of the continuously
vertical sidewalls of the gate stack, we decline to overturn the
common interpretation of Gardner advanced by both the examiner
and appellants. We note that had we found Gardner to disclose
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