Appeal No. 2003-0512
Application 09/184,805
In any event, we cannot accept the examiner’s finding that
Landers teaches polishing the filler layer of a substrate with a
first slurry until a stop layer is partially covered by the
filler layer and partially exposed, and then polishing the
substrate with a second slurry until said stop layer is
substantially completely exposed, as now claimed. In Landers, we
perceive the metallization layer 10 as corresponding to the
claimed filler layer and oxide layer 18 (also denominated by
reference numeral 14) as corresponding to the claimed stop layer.
As to liner layer 12, which may comprise Ti/TiN or Ta/TaN
depending on the composition of the metallization layer 10, if
the liner layer is considered to be part of the metallization
layer, then oxide or stop layer 18 is completely covered by the
“filler layer” (layer 10 + layer 12) at the end of Landers’ first
polishing step (see Fig. 2) and Landers does not teach the
claimed first step of polishing with a first slurry until the
stop layer (i.e., layer 18) is partially covered by the filler
layer and partially exposed. On the other hand, if the liner
layer is considered to be part of the oxide layer, then the “stop
layer” (layer 12 + layer 18) is partially covered by the plug 28
at the end of Landers’ second polishing step (see Fig. 3) and
Landers does not teach the claimed second step of polishing with
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