Appeal No. 1996-2088
Application No. 08/082,432
whole. In re Keller, 642 F.2d 413, 425, 208 USPQ 871, 881 (CCPA 1981). Here, Maeda and Hu
both disclose a three-layer barrier structure comprising a TiN layer for the purpose of suppressing Al
migration/diffusion and the APA suggests oxygenating the TiN layer, i.e., using a TiON layer, to further
suppress Al migration in the TiN grain boundary. Admittedly, the APA does disclose that high
temperature bias sputtering produces a non-uniform deposition of an Al-based material on a Ti/TiON
structure because of a tendency for voids to be produced (specification, page 3, first full para.).
However, claim 22 does not require high temperature bias sputtering deposition of an Al-based
material or deposition onto a TiON layer (answer, pages 7-8). Moreover, Tracy explicitly addressed
the high temperature deposition voiding problem (recognized at col. 1, line 55 - col. 2, line 3) by his
disclosed method which “favors a filled via rather than the formation of a void” (col. 4, lines 39-43).
Therefore, we agree with the examiner that one of ordinary skill in the art would have been motivated
by the combined teachings of the applied references to substitute TiON for the TiN layer in the barrier
structure of Maeda or Hu to further suppress Al migration in the barrier structure as suggested by the
APA. Arguments drawn to the incompatability with and/or use of a high temperature Al-
based material deposition step are not only not commensurate in scope with the claimed invention, but
also ignore the explicit teachings of Tracy for addressing the problem of voiding in high temperature
metal depositions. Thus, these arguments are insufficient to overcome the rejection.
b. claim 19
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