Appeal No. 2005-1220
Application No. 09/270,606 Page 5
at a higher rate than the low structure areas such that the
planarization described is achieved. Kodera does not describe
using a dummy structure2 in the embodiment depicted in Figures 19
E and 19 F, which is consistent with the dummy structure
exclusion of claim 1.
Moreover, Kodera teaches that other appropriate materials
may be employed in the cerium oxide polishing slurry and that the
use of a cerium oxide polishing slurry in accordance with the
method depicted in Figures 19 E and 19 F, as described in the
specification, results in solving problems earlier identified in
the specification. See column 23, lines 1-33 of Kodera. Given
that disclosure of Kodera and the teachings of Grover and Burke
with respect to using other additives including dispersion aids
in a CMP slurry employing cerium oxide, we agree with the
examiner (answer, page 8) that it would have been obvious to one
of ordinary skill in the art at the time of the invention to
employ a slurry modifier in the CMP slurry of Kodera. In this
regard, Grover teaches using additives such as other abrasives,
acids and surface active dispersing agents and Burke teaches that
adding a surfactant or suspension agent, including ethylene
2 Appellant defines a dummy structure as structures that
“are used for the sole purpose of controlling the CMP rate”
(specification, page 1, lines 14-16).
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