Appeal No. 2004-0605
Application 09/411,129
Fitch discloses that such an air-filled region can be formed
by depositing and removing a germanium-silicon alloy sacrificial
layer (col. 8, lines 22-28).
Iranmanesh discloses an integrated circuit which includes a
layer (6) of polycrystalline germanium or polycrystalline
germanium/silicon alloy which is planarized by chemical
mechanical polishing to form electrical isolation regions between
metal interconnect lines (2) (col. 2, lines 54-56; col. 3,
lines 63-67; col. 4, lines 6-11 and 39-48; col. 4, line 56 -
col. 5, line 4; figure 3).
The examiner argues that it would have been obvious to one
of ordinary skill in the art to replace Fitch’s germanium-silicon
alloy with Iranmanesh’s polycrystalline germanium to provide a
superior end product after planarization and to provide a layer
having relatively high resistivity which can be increased by
adding oxygen to the germanium (Iranmanesh, col. 4, lines 60-62)
(answer, page 4). The examiner has not explained why one of
ordinary skill in the art, given that Fitch’s germanium-silicon
alloy layer is removed to form an air space, would have been led
to form Iranmanesh’s polycrystalline germanium layer as part of
Fitch’s end product. Moreover, the examiner has not explained
how, even if this substitution were made, the appellants’ claimed
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