Appeal No. 1998-2948
Application 08/400,861
formed on the wiring layer can also be increased by oxidizing,
boriding, carbonizing or siliciding the surface of the wiring
layer of the invention" (col. 6, lines 41-45). Kiyota teaches
that "[i]n the case of oxidation, anodization can also be
employed" (col. 6, lines 48-49). Thus, Kiyota teaches an
anodic oxidation film on the interconnect conductor. It is
disclosed that "[t]he surface-treated layer usually has a
thickness of 0.1 to 1 µm" (col. 6, lines 54-55), i.e., 1000 Å
to 10000 Å.
Lee discloses an aluminum-yttrium (Al-Y) alloy with
0.2 at% Y as an interconnection conductor in integrated
circuits. The Al-Y alloy has an electrical resistivity
similar to that of pure Al, but the Y is sufficient to
minimize the generation and growth of annealing hillocks as
compared to pure Al (abstract). Hillocks are surface defects
in the form of bumps which can cause fatal problems in
integrated circuits (p. 2546).
Hochido discloses an Al-Y alloy containing 0.1 to
0.5 wt% Y (0.03 to 0.14 at% from Lee which discloses that
0.7 wt% is 0.2 at%) as an interconnection film that has "few
electromigration [defects?] or hillocks" (abstract).
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