Appeal No. 1998-0129 Page 22
Application No. 08/438,062
following quote from McMillan (pages 1 and 2) in support of
their position
There appears, however, to be a general (and
understandable) reluctance in the IC industry to
move away from the well understood and well
characterized silicon dioxide (or silicon nitride)
dielectric system. There are a number of reasons
for this. Choosing the right material for ULSI
DRAM’s is not an easy task. Many of the new
(proposed) high dielectric constant materials have
very complex, multi-component structures that are
difficult to synthesize and contain elements that
are normally considered to be contaminates or
hazardous in a processing area. Some of the well
known high dielectric constant materials (such as
lead zirconate titanate) exhibit ferroelectric
properties such that the dielectric constant
decreases significantly at high frequencies. In
general, most of these new materials are difficult
to produce consistently with existing thin film
deposition equipment.
Appellants go on to state (reply brief, page 4)that “[t]he
above-quoted passage from McMillan et al. merely states that
known high dielectric materials such as lead zirconate
titanate or PZT, exhibit capacitance rolloff at high
frequencies. . . . The
quoted passage (and the entire McMillan et al. reference) says
absolutely nothing about the high frequency performance of BST
materials.” We find that further reading of McMillan
discloses
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