Appeal No. 2002-1167
Application No. 09/089,445
with an inner side of the double sided electrode (figure 8), a
second dielectric layer (32) in contact with the first dielectric
layer and an outer side of the double sided electrode (figure 8),
and a second conductive layer (34), wherein the second dielectric
layer is between the first conductive layer and the second
conductive layer (figure 8). Wu does not disclose the appellants’
first dielectric layer.
The first conductive layers of both Cho (col. 3, line 9) and
Wu (col. 8, line 21) are made of hemispherically grained (HSG)
polysilicon. Both Cho (col. 3, lines 8-10) and Wu (col. 8,
lines 12-30) indicate the HSG polysilicon has roughness which
increases the surface area of the conductive layer. Zahurak
teaches that in a capacitor, “[a] drawback to the use of rugged
polysilicon is that the conductive grains thereof can become
detached from an underlying semiconductor substrate during
subsequent processing and can redeposit between memory cells,
causing electrical shorts or double bit failures of adjacent memory
cells” (col. 1, lines 57-62). The rugged polysilicon referred to
by Zahurak can be HSG polysilicon (col. 4, lines 32-33). Zahurak
conditions the surface of the rugged polysilicon by rapid thermal
nitridization (RTN), thereby forming on the rugged polysilicon a
thin film of silicon nitride (a dielectric layer) (col. 4, line 58
4
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