Ex Parte Dornfeld et al

Board of Patent Appeals and Interferences

Sep 30, 2004

08869328 (B.P.A.I. Sep. 30, 2004)

1
The opinion in support of the decision being entered today was
not written for publication and is not binding precedent of the
Board.
Paper No. 33
UNITED STATES PATENT AND TRADEMARK OFFICE
_______________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_______________
Ex parte DAVID DORNFELD
and
JIANSHE TANG
_______________
Appeal No. 2002-1029
Application No. 08/869,328
_______________
ON BRIEF
_______________
Before FRANKFORT, PATE and McQUADE, Administrative Patent Judges.
PATE, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal from the final rejection of
claims 1, 4, 6, 7, 9 through 15, 17 through 25, and 36
Appeal No. 2002-1029
Application 08/869,328
2
through 40. Claims 2, 3, 5, 8, 16, and 26 through 35 are
cancelled. These are all the claims in the application.
The claimed invention is directed to a chemical-
mechanical planarization of semiconductor wafers. The claimed
process is related to a method of terminating such a planariza-
tion. The present invention involves monitoring acoustic
emission energy with a frequency of over 50,000 Hertz for a
planarization termination signal.
The claimed invention may be further understood with
reference to the appealed claims attached as an appendix to
appellant’s Supplemental Appeal Brief, Paper No. 28.
The references of record relied upon by the examiner
as evidence of obviousness are:
Yu 5,222,329 June 29, 1993
Salugsugan 5,245,794 Sept. 21, 1993
REJECTION
Claims 1, 4, 6, 7, 9 through 15, 17 through 25, and 36
through 40 stand rejected under 35 U.S.C. § 103 as unpatentable
over Yu in view of Salugsugan. According to the examiner, it
would have been obvious to have modified the Yu apparatus and
Appeal No. 2002-1029
Application 08/869,328
3
method with a filter as taught by Salugsugan to halt the polisher
operation. The examiner considers the specific frequency range
of the claimed subject matter to be a result effective variable.
OPINION
We have carefully reviewed the rejection on appeal in
light of the arguments of the appellants and the examiner. As a
result of this review, we have reached the determination that the
applied prior art does not establish the prima facie obviousness
of the claims on appeal. Our reasons follow.
The following represents our findings of fact with
respect to the scope and content of the prior art and the
differences between the prior art and the claimed subject matter.
Yu discloses a method for controlling a chemical-mechanical
polishing operation on a workpiece comprising the steps of
polishing the workpiece with a slurry of abrasives. The
polishing operation generates acoustic energy emissions which
are detected. The sound intensity versus the frequency of the
acoustic emission is measured. Col. 6, lines 3-5. When a
significant change in the sound frequency and amplitude is
Appeal No. 2002-1029
Application 08/869,328
4
detected, the end point of polishing has been reached. Yu
teaches several frequency ranges for his disclosed process. On
the one hand, Yu suggests monitoring frequencies in the audible
range (approximately 20 Hz to 20,000 Hz) using a microphone as a
transducer. However, Yu also discloses using acoustic energy
in the non-audible range (less than 20 Hz or greater than
20,000 Hz). See col. 6, lines 48-51; col. 4, lines 48-53. For
frequencies above 20,000 Hz, Yu states that a contact transducer,
such as a piezoelectric transducer, may be used in lieu of the
microphone. Id. Yu does not specifically disclose detecting
acoustic emissions at frequencies above 50,000 Hz.
Salugsugan discloses a similar process. However,
Salugsugan uses low frequencies to signal the end of polishing,
specifying a low band pass filter to attenuate frequencies above
200 Hz by at least 60 db. Consequently, Salugsugan does not
disclose frequencies above 50,000 Hz.
The examiner is of the view that with respect to the
frequency range above 50,000 Hz, “the values of the mechanical
properties are obvious because they are a matter of determining
optimum conditions by routine experimentation. Discovery of [an]
optimum value of [a] result effective variable in [a] known
Appeal No. 2002-1029
Application 08/869,328
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process is ordinarily within the skill in the art.” See
Examiner’s Answer, page 4. The examiner cites In re Boesch,
617 F.2d 272, 205 USPQ 215 (CCPA 1980). However, in Boesch, it
was held that “optimizing a variable which was known to be result
effective” was within the ordinary skill in the art (emphasis
supplied). Boesch, 617 F.2d at 276, 205 USPQ at 219, quoting
In re Antonie, 559 F.2d 618, 620, 195 USPQ 6, 8-9 (CCPA 1977).
Thus, under such a scenario, the examiner has a burden of
establishing that the prior art recognizes that the variable is
result effective.
In the present case, the patent to Yu merely discloses
sampling acoustic energy in a range above 20,000 Hz. There is no
disclosure that any frequency affects the sensitivity of the
process cutoff or that any frequency above 20,000 Hz is better
than any other frequency. In fact, Yu discloses nothing other
than frequencies above 20,000 Hz may be used. There is certainly
no disclosure that frequency is a variable that can be optimized
to effect a result. Accordingly, in our view, the prior art
taken as a whole, as combined by the examiner, is merely an
invitation to experiment -- an example of obvious to try.
Appeal No. 2002-1029
Application 08/869,328
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An “obvious-to-try” situation exists
when a general disclosure may pique the
scientist’s curiosity, such that further
investigation might be done as a result of
the disclosure, but the disclosure itself
does not contain a sufficient teaching of how
to obtain the desired result, or that the
claimed result would be obtained if certain
directions were pursued. See generally In re
O’Farrell, 853 F.2d 894, 903, 7 USPQ2d 1673,
1681 (Fed. Cir. 1988) (defining obvious-to-
try as when prior art gives “only general
guidance as to the particular form of the
claimed invention or how to achieve it”)
[In re Eli Lilly & Co., 902 F.2d 943, 945,
14 USPQ2d 1741, 1743 (Fed. Cir. 1990)].
The rejection of all claims on appeal is reversed.
REVERSED
CHARLES E. FRANKFORT )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
WILLIAM F. PATE, III ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
JOHN P. McQUADE )
Administrative Patent Judge )
WFP:psb
Appeal No. 2002-1029
Application 08/869,328
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