Appeal No. 2005-0339
Application No. 09/376,039
planarized FSG layer. Also, as noted by the examiner, Usami
teaches that it was known in the prior art to polish and
planarize an FSG layer before performing further operations in
making an integrated circuit. Accordingly, we are satisfied that
it would have been obvious for one of ordinary skill in the art
to planarize the FSG layer of Lee with chemical mechanical
polishing before applying the undoped oxide coating. Although
Usami provides two FSG layers of different composition before
planarizing the top layer, and the presently claimed method
deposits only a single FSG layer, we find that one of ordinary
skill in the art would have found it obvious to eliminate one of
the FSG layers of Usami along with its attendant advantage. See
In re Thompson, 545 F.2d 1290, 1294, 192 USPQ 275, 277 (CCPA
1976); In re Kuhle, 526 F.2d 553, 555, 188 USPQ 7, 9 (CCPA 1975);
In re Edge, 359 F.2d 896, 899, 149 USPQ 556, 557 (CCPA 1966).
Appellants contend that the prior art discussed by Usami
does not teach or suggest the claimed invention "since the peaks
of the FSG layer 302 illustrated therein are also completely
polished away, rather than polished to reduce the height of peaks
to a substantially uniform level" (sentence bridging pages 12 and
13 of principal brief). However, since appellants acknowledge
that "those who are skilled in the art understand that fully
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