Appeal No. 2003-0230
Application No. 09/624,025
ions are then implanted in the bottom of the trench. A nitride
spacer is then formed along the bottom and sidewalls of the
trench, followed by an isotropic etch removing the nitride and
oxide from the bottom of the trench. An oxide deposition then
fills the trench, followed by a planarization step completing the
isolation structure. (Specification, page 3, line 13 - page 4,
line 2).
I. The rejection of Claims 1, 2, 4, 5, 8-10, 12, and 14 under
35 U.S.C. § 103(a) as being unpatentable over Gardner in view
of Arnold and Sheng.
The examiner has found that Gardner teaches all of the steps
of claim 1 except for implanting oxygen into the trench bottom and
forming spacers of nitride. More specifically, the examiner has
found that Gardner provides a substrate, forms a first oxide
layer, deposits a nitride layer, patterns and etches the oxide and
nitride layers to form an opening, and anisotropically etches the
substrate to form trenches. A second oxide layer is grown as the
trench liner and a nitride layer is formed over the oxide layer,
then anisotropically etched back to form spacers, exposing the
substrate at the trench bottom. (Examiner’s Answer, page 3, line
18 - page 4, line 3). The trench is then filled with oxide and
planarized (Id., page 4, lines 11-12).
The appellants have not challenged these findings of the
examiner, stating that “[I]t is agreed that Gardner teaches
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