Appeal No. 2003-1260 Page 10
Application No. 09/850,654
and a spacer that enclose metallic material in a via.” (Brief, p. 5). The conductive structure 9 and
film 13 sit above metallic film 8 in the via. Film 13 is an insulating film meant to prevent the
flow of electrically charged particles into the conductive materials during plasma etching (plasma
damage). Film 13 surrounds conductive structure 9. Together, the two structures 9 and 13
“enclose” the metallic material in the via as claimed.
We conclude that the Examiner has established a prima facie case of anticipation with
respect to the subject matter of claims 16-20 which has not been sufficiently rebutted by
Appellants.
Obviousness
Claims 8, 9, and 18 stand rejected under 35 U.S.C. § 103(a) as obvious over Kimizuka in
view of Hsu. As these claims stand or fall together, we select one claim, claim 8, to represent the
issues on appeal. Claim 8 requires that the metal in the via be an aluminum alloy.
The Examiner acknowledges that Kimizuka does not specifically disclose the use of an
aluminum alloy in the via. The Examiner correctly notes that Kimizuka specifies the use of
tungsten in the specific embodiment of Figure 4. We, however, note that Kimizuka does not
restrict the metal to tungsten. In fact, the Summary of Invention describes the material as a
“contact conductive film” (Kimizuka, col. 3, ll. 7-11, ll. 21-25, and l. 32). Tungsten is simply
one example of a known contact conductive film.
The Examiner looks to Hsu as evidence that aluminum alloys have been used in the prior
art to fill vias. Indeed, Hsu describes tungsten as an alternative to aluminum systems for filling
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