Appeal No. 1997-4027
Application No. 08/300,111
ordinary skill in the art would have been motivated to form the reaction chamber of
Anderson which contains very little spacing between the pedestal and the surrounding
preheat ring in order to (1) control the distribution of gases across the wafer, (2) prevent
the reactant gases from flowing to the backside of the reaction chamber and (3) prevent
the dilution of the reactant gases by the gases which are added to the bottom of the
2
reaction chamber.
Claim 10 adds the following limitation to claim 1: “including a means for rotating
said susceptor support.” When the terms in the claims are written in a “means-plus-
function” format we interpret them as the corresponding structure shown in the
specification or equivalents thereof consistent with 35 U.S.C. § 112, paragraph 6. In re
Donaldson, 16 F.3d 1189, 1193, 29 USPQ2d 1845, 1848 (Fed. Cir. 1994). Nowhere
does claim 10 recite sufficient structural limitations for the
2 We recognize that the ultimate way to prevent the flow of reactive gases to the backside of the
reaction chamber is to eliminate the space between the pedestal and the preheat ring. It is also noted that
Anderson’s preferred embodiment calls for the rotation of the pedestal. The purpose of rotating the
substrate is to improve the uniformity of the time averaged physical and chemical environment of the
wafer during processing. (Column 1, lines 43-47). One of ordinary skill in the art who did not desire the
improvements associated with a rotating pedestal would have been motivated to exclude the rotating
pedestal from the reaction chamber of Anderson. See
In re Larson, 340 F.2d 965, 969, 144 USPQ 347, 350 (CCPA 1965) (Omission of additional framework
and axle which served to increase the cargo carrying capacity of prior art mobile fluid carrying unit
would have been obvious if this feature was not desired.); and In re Kuhle, 526 F.2d 553, 555, 188
USPQ 7, 9 (CCPA 1975) (deleting a prior art switch member and thereby eliminating its function was an
obvious expedient).
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