Appeal No. 2000-1702
Application No. 08/841,908
silicon dioxide and contain carbonaceous impurities and that it is conventional in the art to
treat such carbonaceous impurities with an ozone and oxygen plasma to remove those
carbonaceous impurities. See Answer, page 3. We disagree with the examiner’s analysis
and assumptions. The explicit teaching in Hochberg was directed to TEOS film deposition
at a temperature below 350o C in the presence of oxygen. In contrast the films of Nguyen
are deposited at temperatures between 350o and 450o C in the presence of oxygen, a
nitrogen containing gas and helium. See Nguyen, column 4, lines 33-48. Under the
conditions disclosed by Nguyen, one cannot necessarily conclude that the first nitrogen
containing silicon layer deposited necessarily contains carbonaceous impurities. Moreover,
the burden is on the examiner to show that carbon impurities would have been found
under the conditions utilized by Nguyen. This burden has not been met. Accordingly, it is
not seen why the person having ordinary skill in the art would have treated the first
nitrogen containing silicon oxide layer of Nguyen with a plasma ozone process in the
presence of excess oxygen as suggested by Hochberg in the background of his invention.
Furthermore, we agree with the appellants’ argument that Nguyen ‘s process does
not include hydrogen and organic polymer residues in the silicon layer. See Brief,
sentence bridging pages 10 and 11. Accordingly, as the Nguyen plasma film has not been
shown to contain, “either hydrogen or organic polymer residue therein, there is no possible
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