Appeal No. 1998-1850
Application No. 08/596,613
As shown in the above-identified section of column 2 of the reference, Havemann
recognizes the desirability of “high-aspect ratio gaps.” While his disclosed method is
suitable for the disclosed “2:1” embodiment, Havemann does not use the technique of
implanting metal (titanium) ions into the contact opening, and thereby creating a titanium
silicide layer between the contact opening and the active region beneath the contact
opening. According to appellants, as disclosed, for example, on page 6 and the
paragraph bridging pages 17 and 18 of the instant specification, the metal silicide layer
allows construction of devices having greater aspect ratios.
That recognition, however, was in the prior art. Tsunohara discloses, principally on
page 8 and the final paragraph of page 10 of the English translation, that greater aspect
ratios than the one disclosed by Havemann can be obtained by implanting metal ions into
the contact opening, and forming a metal silicide layer, in the manner as set forth by instant
claim 1. Havemann does not warn the artisan that his method for constructing the dual
gate structures is incompatible with any refinements for yielding higher aspect ratios. Cf.
Para-Ordnance, 73 F.3d at 1090, 37 USPQ2d at 1241: “That the Browning Hi-Power does
not have a converging frame does not require a finding that it ‘teaches away.’ While it
does not teach convergence, there is nothing about the Browning Hi-Power to warn a
person of ordinary skill against using convergence.”
Even if, as appellants allege, the second embodiment disclosed by Havemann
places constraints on the remainder of Havemann’s disclosure, we do not find the first
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