Appeal No. 2005-0585
Application No. 09/821,478
uses an O2-containing gas in the plasma etching process (col. 3,
lines 43-52). Answer, page 6.
The examiner states that Tao does not teach correcting for
the CD-bias, and does not specify positive or negative resists.
Answer, page 7. The examiner states that Tao’s layers include
an oxide layer, and an ARC, but not TEOS. Answer, page 7.
The examiner finds that Ma teaches that CD-bias or “profile
microloading” is known (col. 1, lines 60- col. 2, line 21). The
examiner states this prior art process corrects for the
microloading effect by adjusting the RF power (and hence the
space charge). The examiner states that the resist sputtering
effect is also adjustable by adjusting the frequency of the RF
power (col. 2, lines 32-64). Answer, page 7.
The examiner also finds that Ma discloses further adjusting
the etch parameters to correct for the CD bias. These include
lowering the frequency (Fig. 5) and increasing the RF power
(col. 3, lines 10-27). The system is operated at 0-100mT (col.
5, lines 45-49). Answer, page 7.
The examiner states that Ma does not specify positive or
negative photoresists (claim 4). However, the examiner states
that the choice of a type of photoresist is uniquely determined
by the process.2 Answer, page 7.
With respect to the claimed “trim” aspect of the etching
step of claim 1, the examiner finds that Horak teaches the
concept of trimming the resist and ARC (anti-reflective coating)
to compensate for a nested-isolated etching bias of the gate
(col. 6, lines 49-col. 7, lines 44). The examiner also finds
that Horak teaches that nested-iso print bias is also corrected
2 We find that Horak specifically teaches that the type of resist chosen
is a design variable. See column 10, lines 7-10 of Horak. Hence, we
agree with this statement made by the examiner.
4
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