Appeal No. 2004-0085
Application No. 09/876,447
“CLEAN THE POLISHING SURFACE OF THE POLISHING PAD.” It follows
that Figure 3 also provides evidence that Koos discloses a method
of cleaning a pad and a wafer.
With respect to the §103(a) rejection of dependent claim 8,
the examiner cites Laursen to support an obviousness conclusion
with respect to using citric acid in formulating Koos’ acid-
containing solution. Appellants broadly respond that Laursen
“does not lend any additional weight in a §103(a) rejection of
the present in-situ cleaning method” and maintain that they have
“clearly shown above that the primary reference of Koos et al
does not teach a method for in-situ cleaning of a pad and a wafer
during CMP, including the step of mixing an acid-containing
solution from water and an acid selected from the group
consisting of citric acid, HCOOH, CH3COOH, HNO3, H2SO4 and HF”
(Brief, page 9). The examiner replies on pages 5 through 6 of
the Answer that Laursen discloses the use of citric acid in an
acid-containing solution and that “it would have been obvious to
one having ordinary skill in the art at the time the invention
was made to use citric acid as disclosed by Laursen et al in
place of hydrofluoric acid (HF) with the method and apparatus of
Koos et al in order to remove copper-containing debris from a
surface of a polishing pad.”
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