Appeal No. 2003-1081
Application 08/581,347
appropriate combinations of seal materials and heat transfer
gases can be chosen to provide substantially uniform heat
transfer. This portion of the specification discloses that heat
transfer functions for the seal and the heat transferring gas can
be defined and equated to “determine the ratio or the relation
between the thermal conductivity of the gas and the thermal
conductivity of the seal such that the heat transfer between the
lower electrode and the substrate is substantially uniform across
the substrate” (page 9, lines 24-27), but does not provide a
standard for determining the scope of “substantially”.
The discussion in the appellant’s specification regarding
the prior art and the appellant’s figure 4b further indicates
that the scope of “substantially uniform” is unclear with respect
to the heat transfer across the substrate. The discussion of the
prior art indicates that the periphery of the substrate, which
touches the cooled lower electrode as shown in the appellant’s
figure 1, is cooler than the central portion of the substrate
which, due to bowing of the substrate by the heat transferring
gas, is farther away than the periphery of the substrate from the
lower electrode (page 1, lines 19-21; page 3, lines 1-8). The
appellant’s figure 4b and the discussion thereof (page 11,
lines 21-24) indicate that the periphery of the appellant’s
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