Appeal No. 2001-2082
Application No. 08/943,146
possibilities. The mere fact that a certain thing may result for
a given set of circumstances is not sufficient.” Id. 948 F.2d
at 1269, 20 USPQ2d at 1749.
After a review of Mikkor, we agree with Appellants’
assertion that the gold-silicon eutectic portion containing an
oxide of metal that has deoxidized silicon oxide and the gold
layer interposed between the eutectic portion and the second
substrate are absent in the reference. As depicted in Fig. 1,
Mikkor forms silicon oxide layer 2 over troughs in each of
substrates 1A and 1B for preventing metal diffusion barrier 3
from reacting with the silicon substrate (col. 3, lines 27-34).
Mikkor also forms a titanium/tungsten layer over the oxide layer
as metal diffusion barrier 3 for blocking the diffusion of gold
into the silicon substrate (col. 3, lines 35-43). The troughs
are filled with polysilicon to the level of substrate surface and
gold strip 5, having a width narrower than that of the trough, is
formed on one of the substrates over the polysilicon-filled
trough (col. 3, lines 44-51). Finally, the substrates are
aligned, brought together and heated in a thermal gradient. As
shown in Fig. 2, the gold layer and the silicon form eutectic
droplet or line 6 which migrates through recrystallized silicon
area 4 until it reaches barrier layer 3 and solidifies when the
7
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