Appeal No. 2004-0784
Application 09/826,078
“it into a cool chamber where the substrate would be cooling down,” and because Wolf teaches
step coverage heating during deposition (page 361), it would have been obvious to one of
ordinary skill in the art to heat the chamber during removal of the first substrate and the
introduction of the second substrate so that the substrate does not have to be reheated, noting that
more than one substrate can be processed at one time in view of page 2, lines 11-15, of
appellants’ specification (answer, pages 5-6). The examiner further finds that “it would be
common sense” to one of ordinary skill in this art “to keep the chamber heated in order to”
maintain “the continuity of the whole process” (answer, page 6). The examiner contends that
appellants’ contrary presumption that the heating of the chamber ceases with the heating element
ceases when the first wafer is removed and is not begun again until the second wafer is placed in
the chamber, “is assumptive and without support of evidence” (answer, page 6).
In the reply brief, appellants point out that “the Examiner [has] been unable to identify a
specific location in a cited reference which discloses” the requirement for “heating continuously
between the removal of the first substrate and the introduction of the second substrate” (pages 3
and 4). Appellants argue that there is no factual basis for the examiner’s contentions with respect
to what “makes sense” and is “common sense” to one of ordinary skill in this art with respect to
the claimed nickel deposition process (reply brief, pages 2-3 and 4-5).
We fail to find in Gupta any teaching with respect to the processing involved with the
deposition of nickel on a substrate (see, e.g., col. 2, lines 45-49), but the reference does disclose
the formation of a metal silicide by rapid thermal annealing (RTA) and the removal of unreacted
nickel which can require heating (col. 3). In the survey text, Wolf discloses that target heating
can result from the “natural” sputtering process or from a heating element (e.g., pages 344 and
367), heating with respect to deposition in the pre-processing chamber or during deposition
(pages 360-61), and that in some instances, “targets must be adequately cooled to prevent
warpage” (page 362). Wolf also discloses “that although it is difficult to measure the exact
temperature on the wafer surface during deposition, in practice it is possible to reproduce the
same heating from run-to-run” (page 367), as well as a number of sputter system configurations,
including the so-called “static” system involving pre-heating and deposition “stations” in what
appears to be the same chamber (pages 362-65). Chen discloses heating during such process
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