Appeal No. 2002-0897
Application 09/303,020
The appellants argue that Roy uses a low concentration HF
spray containing 0.25-1.0 wt% HF, whereas Doan’s required HF dip
uses a higher HF concentration of 5-100 parts by volume of a
49% HF solution per volume of water, and that Roy’s brush
scrubbing does not lend itself to Doan’s method which requires
much more intense HF processing (reply brief, pages 4-5).
Actually, both Roy (col. 5, lines 36-38) and Doan (col. 3,
lines 60-62) indicate that the HF treatment is optional.
Regardless, Roy’s teaching that brush scrubbing is effective for
removing particles and ionic and metallic contaminants (col. 5,
lines 38-39) would have fairly suggested, to one of ordinary
skill in the art, use of brush scrubbing with Doan’s megasonic
cleaning and optional HF treatment to further clean the layer
surface.
The appellants argue that a comparison of split conditions
“B” and “D” in Roy’s figure 13 indicates that Roy’s HF spray,
when used in combination with brush scrubbing, appears relatively
ineffective for reducing total defect counts (reply brief,
page 5). Roy teaches that figure 13 indicates that the HF spray
after scrubbing removes most of the metal contaminants to below
detection limits (col. 6, lines 30-32), and figure 13 shows that
the average total defect count when brush scrubbing is used alone
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