Ex Parte Usui et al

Board of Patent Appeals and Interferences

Feb 19, 2009

10242425 (B.P.A.I. Feb. 19, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte TATEHITO USUI,
KEN YOSHIOKA, SHOJI IKUHARA, KOUJI NISHIHATA, KAZUE
TAKAHASHI, TETSUNORI KAJI, and SHIGERU NAKAMOTO
____________

Appeal 2008-5869
Application 10/242,4251
Technology Center 1700
____________
Heard: 9 January 20092
Decided: 3February 24, 2009
____________

Before TERRY J. OWENS, MARK NAGUMO, and
KAREN M. HASTINGS, Administrative Patent Judges.

NAGUMO, Administrative Patent Judge.

1 Application 10/242,425, Etching End Point Judging Device, filed
13 September 2002 as a division of an application filed 1 December 1999.
The specification is referred to as the “425 Specification,” and is cited as
“Spec.” The real party in interest is listed as Hitachi, Ltd. (Appeal Brief,
filed 20 February 2007 (“Br.”), 1.)
2 See the Court Reporter’s transcript, of record.
3 The two month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, begins to run from the decided date
shown on this page of the decision. The time period does not run from the
Mail Date (paper delivery) or Notification Date (electronic delivery).

Appeal 2008-5869
Application 10/242,425

DECISION ON APPEAL
A. Introduction
Tatehito Usui, Ken Yoshioka, Shoji Ikuhara, Kouji Nishihata, Kazue
Takahashi, Tetsunori Kaji, and Shigeru Nakamoto (“Usui”) timely appeal
under 35 U.S.C. § 134(a) from the final rejection4 of claims 5-8 and 13-24.
We have jurisdiction under 35 U.S.C. § 6(a). We AFFIRM.
The subject matter on appeal relates to a plasma processing apparatus
characterized in part by a calculator that calculates a time series of a
differential coefficient data by a specified method.
Representative Claim 5 is reproduced from the Claims Appendix to
the Principal Brief on Appeal:
Claim 5
A plasma processing apparatus for etching a surface of a sample
disposed inside a chamber using a plasma generated therein,
comprising:
[a] an optical detector which detects light emitted inside said
chamber during the etching process;
[b] an A/D converter which outputs time series data
corresponding to an emission intensity data for the light
detected by said optical detector;
[c] a first digital filter which performs smoothening of said time
series data and outputs a smoothened time series data;
[d] a calculator which calculates a time series of a differential
coefficient data by using a polynominal [sic: polynomial?]
adaptation smoothening differential method;
[e] a second digital filter which performs smoothening of said
time series of the differential coefficient and outputs a

4 Office Action mailed 18 April 2006 (“Final Rejection,” cited as “FR”).
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Application 10/242,425

smoothened time series data of the differential coefficient; and
[f] a judgment device which judges a status of the etching by
comparing said smoothened differential coefficient with a
predetermined value.
(Claims App., Br. 17, square bracketed labels and indentation added.)
Independent claim 13 is similar, except that the calculator specified in
step [d] uses “an S-G method”5.
Dependent claims 7, 15, 19, and 23 (hereinafter, “display claims”)
recite the further limitation that a display displays smoothed data.
Dependent claims 8, 16, 20, and 24 recite the further limitation that a
display displays an “occurrence of an abnormality during the etching with
said smoothened time series data of the differential coefficient.”
The Examiner has maintained the following grounds of rejection:6
A. Claims 5-7, 13-15, 17-19, and 21-23 stand rejected under
35 U.S.C. § 103(a) in view of the combined teachings of Liu,7
Sakamoto,8 Tracy,9 and dePinto.10

5 The “S-G method” appears to be a method of “differential processing.”
See, e.g., 425 Specification 22, ll. 20-22. The “polynominal adaptation
smoothening differential method” recited in claim 1 appears to have been
described in an article by A. Savitsky and M.J.E. Golay, 36 Analytical
Chem. 1627 (1964). (Spec. 20, ll. 1-16.)
6 Examiner’s Answer mailed 25 June 2007. (“Ans.”)
7 Alexander F. Liu, Method and Apparatus for Detecting Optimal Endpoints
in Plasma Etch Processes, U.S. Patent 5,738,756 (14 April 1998).
8 Takashi Sakamoto and Satoshi Makita, Advanced Waveform Observation
System using Waveform Soothing with Restricted Waveform Level
Difference, U.S. Patent 5,129,721 (1992).
9 David H. Tracy et al., Analyzing Spectrometric Data, U.S. Patent
6,029,115 (2000), based on an application filed 30 September 1997.
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Application 10/242,425

B. Claims 8, 16, 20, and 24 stand rejected under
35 U.S.C. § 103(a) in view of the combined teachings of Liu,
Sakamoto, Tracy, dePinto, and Kosugi.11
Usui contends that the failure of Liu, which was filed in 1995, to use
the polynomial adaptation method or the SG method, which were published
in 1964, shows that the Examiner’s rejection is the result of hindsight
reconstruction and the application of an improper “obvious to try” standard.
(Br. 8-9.) Similarly, Usui contends that neither Sakamoto nor Tracy disclose
using such mathematical techniques in combination with a plasma
processing apparatus for etching surfaces of samples as recited in the claims.
(Id. at 9.)
Moreover, according to Usui, the mathematical methods recited in the
claims process data obtained during plasma etching to achieve a “synergistic
effect” (Br. 10, l. 2) that satisfies the need for “accurate and high speed
judgment of the end of etching during plasma processing” (id. at 10, 1st full
para.). Liu, in contrast, is said to teach an averaging method that requires
calculation of a normalization value averaged over a number of samples.
(Id. at 10-11.). Thus, the methods used by Liu to reduce noise in the data
and to increase the accuracy of the analysis are said to require a longer time
to determine data for the “target time,” i.e., the time to stop plasma etching,
because “it is necessary to take data at many time points before and after the
target time or length in the time interval of these time points from the target
10 Victor M. dePinto, Adaptive Line Noise Canceler and Detector for ECG
Signals, U.S. Patent 6,041,250 (2000), based on an application filed 20 May
1998.
11 Makoto Kosugi, Plasma Processing System, U.S. Patent 6,197,116 B1
(2001), based on an application filed 29 August 1997.
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Appeal 2008-5869
Application 10/242,425

time.” (Id. at 11.) In contrast, Usui urges, the claimed method rapidly and
accurately calculates the progress of etching by fitting the acquired data by a
polynomial in a way that makes it possible “to reconcile detection of high
accuracy and detection in a short time”—features that are not, in Usui’s
view, disclosed or suggested by the combined references. (Br. 14.) The
addition of dePinto, which teaches Butterworth filters as low pass filters,
does not, Usui argues, overcome the deficiencies of the other references.
(Br. 14.)
Similarly, in Usui’s view, the failure of Sakamoto to disclose the
display of smooth data representative of light detected from the plasma
etching of a sample in a plasma processing chamber, which is used to
determine the status of the etching, highlights the failure of Sakamoto, in
combination with the other applied references, to render the claimed subject
matter obvious. (Br. 14-15.) Likewise, Usui urges that Kosugi does not
cure the deficiencies of the other references, and that Kosugi does not
disclose a display that “effects display in the manner recited” in the claims.
The Examiner finds that Liu teaches a plasma etching apparatus and
methods, including end point judging based on optical emission
spectroscopy that meet all the limitations [a], [b], [c], [e], and [f] of the
independent claims, but for the specific smoothing and differentiation
techniques recited in step [d]. (Ans. 4.) The Examiner finds that Sakamoto
discloses noise filtering by polynomial adaptation, as taught by Savitsky and
Golay. (Id. at 5.) The Examiner finds further, regarding the “display
claims,” that Sakamoto teaches the operator may monitor process
performance via a display of the smoothed data. (Id.) The Examiner also
finds that Tracy characterizes the analysis of spectrometric data by Savitsky
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Application 10/242,425

and Golay techniques as being “conventional.” (Id.) The Examiner
concludes that the application of conventional mathematical techniques for
analysis of optical signals for endpoint detection would have been obvious.
(Id. at 6.)
Similarly, the Examiner finds that Kosugi teaches a plasma etching
apparatus with end point detection, a prediction, diagnostic, and control unit
connected to an alarm to alert the operator of the need for process control.
(Ans. 6.) The Examiner concludes that it would have been obvious to
display an occurrence of an abnormality during etching, as further recited in
claims 8, 16, 20, and 24. (Id.)
The dispositive issue is, has Usui shown that the Examiner relied on
hindsight to determine that it would have been obvious to substitute the
methods of mathematical analysis recited in the claims for the methods used
by Liu?
C. Discussion
Usui does not dispute the Examiner’s findings regarding the teachings
of the individual references. Nor does Usui dispute the Examiner’s
determination that the references, as combined, meet the limitations of the
appealed subject matter. Rather, Usui disputes the propriety of the
combinations of teachings.
The burden in on Usui, as the Appellant, to prove harmful error in the
Examiner’s rejections. See, e.g., In re Kahn, 441 F.3d 977, 985-86 (Fed.
Cir. 2006) (“On appeal to the Board, an applicant can overcome a rejection
[under § 103] by showing insufficient evidence of prima facie obviousness
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Application 10/242,425

or by rebutting the prima facie case with evidence of secondary indicia of
nonobviousness.”) (citation omitted).
Obviousness is a legal conclusion based on factual inquiries including
the scope and content of the prior art, the differences between the prior art
and the claimed subject matter, and the level of ordinary skill in the pertinent
art. Graham v. John Deere Co., 383 U.S. 1, 17 (1966). The Supreme Court
has recently explained that the “obvious to try standard may be indicative of
obviousness: “[w]hen there is a design need or market pressure to solve a
problem and there are a finite number of identified, predictable solutions, a
person of ordinary skill has good reason to pursue the known options within
his or her technical grasp. If this leads to the anticipated success, it is likely
the product not of innovation but of ordinary skill and common sense. In
that instance the fact that a combination was obvious to try might show that
it was obvious under § 103.” KSR Int'l Co. v. Teleflex Inc., 127 S.Ct. 1727,
1742 (2007). The Court also noted that “a court must ask whether the
improvement is more than the predictable use of prior art elements according
to their established functions.” Id. at 1740. Evidence of unexpected results,
if presented, must be considered, but, as the Federal Circuit has instructed
repeatedly, “by definition, any superior property must be unexpected to be
considered as evidence of non-obviousness.” Pfizer, Inc. v. Apotex, Inc.,
480 F.3d 1348, 1371 (Fed. Cir. 2007) (citation omitted).
Usui does not dispute that the references show that the various
elements of the claimed invention were well-established and familiar to
persons having ordinary skill in the relevant arts. In particular, Usui does
not dispute that the use of techniques such as those taught by Savitsky and
Golay were well known in the manipulation, including smoothing, of noisy
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Application 10/242,425

spectroscopic data. Nor does Usui dispute that the use of the relevant
spectroscopic, mathematical, and computer control techniques recited in the
claims were within the level of ordinary skill in the relevant arts.
We conclude, based on the record before us, that the claimed
invention would indeed have been “obvious to try,” and that, within the
guidelines set out by the Supreme Court, “§ 103 likely bars its patentability.”
KSR, 127 S.Ct. at 1740. Liu’s silence as to the recited mathematical
methods is, by itself, of little moment, as there are many ways to solve a
problem. Moreover, Usui, in its principal Brief on Appeal, has not directed
our attention to any credible evidence that those skilled in the relevant art
had rejected or disparaged Savitsky-Golay techniques in a similar problem,
or had identified some hurdle that had yet to be overcome before Savitsky-
Golay techniques could be employed with a reasonable expectation of
success in the field of plasma etching control.
We must still ask whether the improvements Usui alleges are due to
their claimed process have been shown to be more than the predictable use
of prior art elements according to their established functions. In other
words, are the improvements unexpected?
Usui’s Brief, however, does not direct our attention to credible
evidence in the record as to what levels of accuracy and speed would have
been obtained (or expected), by the methods used by Liu, nor how those
levels compare with the levels of accuracy and speed obtained by the
claimed methods. Nor has Usui directed our attention to credible evidence
in the record that the differences, what ever they are, would have been
unexpected.
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We conclude that, on the present record, Usui has failed to carry its
burden of proving unexpected results compared to the applied prior art. We
therefore AFFIRM the rejection of claims 11 and 13.
Usui’s arguments for patentability of the display claims and the claims
covering the display of an abnormal condition rely on the patentability of the
underlying independent claims. The addition of a display device to an
apparatus designed to control a process to assist in the control of the process,
particularly to display the “occurrence of an abnormality,” would have been
obvious if the underlying process were obvious. Thus, all the dependent
claims, as argued, fall with the independent claims.
D. Order
We AFFIRM the rejection of claims 5-7, 13-15, 17-19, and 21-23
under 35 U.S.C. § 103(a) in view of the combined teachings of Liu,
Sakamoto, Tracy, and dePinto.
We AFFIRM the rejection of claims 8, 16, 20, and 24 under
35 U.S.C. § 103(a) in view of the combined teachings of Liu, Sakamoto,
Tracy, dePinto, and Kosugi.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED
tc
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