Ex Parte FÖH

Board of Patent Appeals and Interferences

Jun 25, 2010

10549081 (B.P.A.I. Jun. 25, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte DENNIS FOH
____________

Appeal No. 2009-005989
Application 10/549,081
Technology Center 1700
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Decided: June 25, 2010
____________

Before CHUNG K. PAK, CHARLES F. WARREN, and
TERRY J. OWENS, Administrative Patent Judges.

PAK, Administrative Patent Judge.

DECISION ON APPEAL
Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’s final
rejection of claims 1 through 9, all of the pending claims in the above-
identified application. See page 3 of the Appeal Brief (“App Br.”) filed
September 8, 2008. We have jurisdiction under 35 U.S.C. §§ 6 and 134.
STATEMENT OF THE CASE
The subject matter on appeal is directed to “a method for etching a
sample in an etching system” and “an etching system for etching a sample”
(Spec. 1). Details of the appealed subject matter are recited in representative
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claims 1and 61 reproduced from the Claims Appendix to the Appeal Brief as
shown below:
1. A method for etching a sample in an etching system utilizing a
plasma of a reactive gas mixture that is fed through a reaction chamber with
an inlet orifice and with an outlet orifice, in which the sample to be etched is
located, with a device for igniting and maintaining the plasma, comprising:
inputting a reactive gas mixture to the reaction chamber, with a
control unit for the etching system adjusting the process parameters to their
setpoints, and with the plasma being ignited in a second step;
setting parameters of the etching system at least are stored in a
memory, during the first process step;
inputting an inert gas to the reaction chamber after the storage of the
setting parameters;
modifying the gas flow rate of the inert gas, the gas flow rate is
determined that causes the same setting parameters as the reactive gas
mixture did previously;
inert gas is fed into the reaction chamber at the determined reference
gas flow rate of inert gas until the setting parameters in the process are
stabilized;

1Appellant separately argues the limitations recited in claims 1 and 6 (App.
Br. 5-14). Therefore, for purposes of this appeal, we select claims 1 and 6
and decide the propriety of the Examiner’s §§ 103(a) and 102(b) and
rejections set forth in the Answer based on these claims alone. See 37
C.F.R. § 41.37(c)(1)(vii) (“When multiple claims subject to the same ground
of rejection are argued as a group by appellant, the Board may select a single
claim from the group of claims that are argued together to decide the appeal
with respect to the group of claims as to the ground of rejection on the basis
of the selected claim alone.”).

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the inert gas is then switched over to reactive gas mixture while
retaining the setting parameters, the plasma is then ignited.
6. Etching system for etching a sample, comprising: utilizing a
reactive gas that can be fed through a reaction chamber with an inlet orifice
for the infeed of gas and with an outlet orifice for the discharge of gas, in
which the sample to be etched is located, with a device for generating an
electrical high voltage field to ignite and maintain the plasma,
wherein the reactive gas can be fed through the reaction chamber in a first
stabilization step, with a control unit for the etching system being provided
to adjust the process parameters to their setpoints, and with the plasma being
ignitable in a second step,
characterized in that
the setting parameters of the etching system can be stored in a
memory while the process is running,
an inert gas can be fed through the reaction chamber instead of the
reactive gas after the storage of the setting parameters,
by modifying the gas flow rate of inert gas, the reference gas flow rate
that causes the same setting parameters as the reactive gas mixture did
previously can be determined and likewise stored in the memory,
to etch the sample, the reactive gas can be fed through the reaction
chamber instead of the inert gas, while retaining the determined setting
parameters,
and the plasma can be ignited without stabilization with reactive gas
and without a time delay.
As evidence of unpatentability of the claimed subject matter, the
Examiner relies on the following prior art references at page 3 of the Answer
(“Ans.”) dated October 14, 2009:
Kao 6,125,859 Oct. 3, 2000
Okada 2002/0014470 A1 Feb. 7, 2002

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Appellant requests review of the following grounds of rejections set
forth in the Answer:
1. Claims 6 through 9 under 35 U.S.C. § 102(b) as anticipated by
the disclosure of Kao; and
2. Claims 1 through 5 under 35 U.S.C. § 103(a) as unpatentable
over the combined teachings of Okada and Kao2. (See Ans. 3-10 and App.
Br. 6)
ISSUES AND CONCLUSIONS
With respect to the § 102(b) rejection of claims 6 through 9, the
dispositive question is: Has Appellant identified reversible error in the
Examiner’s finding that the claimed system is identical to the system taught
by Kao within the meaning of 35 U.S.C. § 102(b)? On this record, we
answer this question in the negative.
With respect the § 103(a) rejection of claims 1 through 5, the
dispositive question is: Has Appellant identified reversible error in the
Examiner’s determination that one of ordinary skill in the art would have
been led to employ Kao’s controller for adjusting the process parameters in
the etching method taught by Okada within the meaning of 35 U.S.C. §
103(a)? On this record, we answer this question in the negative.
ANALYSIS, FINDINGS OF FACT, AND PRINCIPLES OF LAW
35 U.S.C. § 102(b)
Appellant does not dispute the Examiner’s finding that Kao describes
a system for etching or cleaning the interior surface of a semiconductor

2 Appellant inadvertently excludes Kao (‘859) in requesting review of this
obviousness rejection set forth in the final Office action dated January 8,
2008 and repeated in the Answer.
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processing chamber, which is structurally identical to the system recited in
claim 6. (Compare Ans. 3-6 with App. Br. 7-8 and Reply Br. 2-3).
According to Kao, the deposit formed on the interior wall of a
semiconductor processing chamber is caused by the same reactants used for
depositing a layer on a semiconductor substrate (col. 1, ll. 29-49 and col. 6,
ll. 4-21). Kao employs a gas containing halogen radicals to react with the
accumulated deposit resulting from the same gaseous reactants used for
forming semiconductor films to remove the deposit without over-etching the
processing chamber interior surfaces (col. 1, ll. 29-49 and col. 6, ll. 8-21).
When, as here, the system taught by Kao is structurally identical to that
claimed and can be used for etching the deposit formed from the same
reactants used to deposit films on semiconductor substrates, there is a
reasonable basis for the Examiner to believe that Kao’s system is capable of
performing the claimed function, i.e., etching an unidentified sample,
inclusive of etching deposits or layers on semiconductor substrates. As our
reviewing court stated in In re Schreiber, 128 F.3d 1473, 1478 (Fed. Cir.
1997):
A patent applicant is free to recite features of an apparatus
either structurally or functionally. See In re Swinehart, 439
F.2d 210 (CCPA 1971) (“[T]here is nothing intrinsically wrong
with [defining something by what it does rather than what it is]
in drafting patent claims.”). Yet, choosing to define an element
functionally, i.e., by what it does, carries with it a risk. As our
predecessor court stated in Swinehart, 439 F.2d at 213:

where the Patent Office has reason to believe that a
functional limitation asserted to be critical for
establishing novelty in the claimed subject matter
may, in fact, be an inherent characteristic of the
prior art, it possesses the authority to require the
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applicant to prove that the subject matter shown to
be in the prior art does not possess the
characteristic relied on.

Appellant contends that Kao does not teach using its system for
etching a sample, e.g., a semiconductor. However, Appellant has not shown
that Kao’s system is not capable of performing the claimed function, i.e.,
etching an unidentified sample. See, e.g., In re Best, 562 F.2d 1252, 1255
(CCPA 1977) (When the claimed and prior art products are identical or
substantially identical, the Examiner can require Appellant to prove that the
prior art product does not inherently possess the characteristic of their
claimed product.). Nor has Appellant shown that the claimed functional
limitation, i.e., etching an unidentified sample, renders the claimed system
structurally different than that taught by Kao. See, e.g., Catalina Marketing
Int'l., Inc. v. Coolsavings.com Inc., 289 F.3d 801, 809 (Fed. Cir. 2002)(The
patentability of an apparatus claim depends only on the claimed structure,
not on the use or purpose of that structure.); see also In re Danly, 263 F.2d
844, 848 (CCPA 1959); In re Gardiner, 171 F.2d 313, 315-16 (CCPA
1948).
Thus, on this record, we concur with the Examiner that Kao describes
the system recited in claims 6 through 9 within the meaning of 35 U.S.C. §
102(b).
35 U.S.C. § 103
Appellant does not dispute the Examiner’s finding that
'470 [(Okada)] teaches a method for etching a sample in an
etching system utilizing a plasma of a reactive gas mixture,
involving inputting both reactive gas mixtures into the reaction
chamber, that is fed through a reaction chamber in which the
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sample to be etched is located ([0091-0100], Fig 5 and 6). '470
[(Okada)] additionally teaches that the etching of a substrate
can be controlled in a desired manner by controlling the
pressure, the gas flow rate, and other conditions ([0099]).
[(Compare Ans. 6, with App. Br. 8-9 and Reply Br. 2-3.)]
Although the Examiner acknowledges at page 6 of the Answer that Okada
does not specify how such controls are imposed, the Examiner finds, and
Appellant does not dispute, that Kao teaches a system controller, including a
software stored in a memory, being used with a plasma processing chamber
having gas inlet and outlet ducts, to control the inputs, flow rates, and
amounts of the inert gas and reactive gas mixture to produce a desired
plasma in the claimed manner. (Compare Ans. 7-8 with App. Br. 8-9 and
Reply Br. 2-3.)
Given the need for controlling the reaction parameters for producing a
plasma useful for etching, we concur with the Examiner that one of ordinary
skill in the art would have been led to employ a conventional system
controller, such as the one taught by Kao, for the purpose of controlling the
inputs, flow rates, and amounts of the inert gas and reactive gas mixture in
the manner claimed to produce desired plasma useful for the etching process
of Okada.
Appellant contends at pages 8 and 9 of the Appeal Brief that:
Since Koa [sic] merely discloses cleaning of interior
surfaces of the etching system, it is respectfully submitted that
even if combined, Okada and Kao still fail to disclose the
claimed invention since Koa [sic] merely disclosed [sic]
cleaning the interior walls of a reaction chamber, and has
nothing to with controlled etching of a substrate. [(Emphasis
added.)]

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However, the fact that Kao does not teach controlled etching of a substrate
does not indicate that the collective teachings of Okada and Kao would not
have suggested controlled etching of a substrate. In fact, as indicated supra,
Appellant does not dispute the Examiner’s finding that Okada teaches such
controlled etching of a substrate. Nor does Appellant dispute the
Examiner’s determination that it would have been obvious to employ Kao’s
controller and steps for controlling the inputs, flow rates, and amounts of an
inert gas and a reactive gas mixture in the claimed manner for forming
etching plasma in the etching process of Okada.
Accordingly, based on this record, including due consideration of
Appellant’s arguments, we determine that the preponderance of evidence
weighs most heavily in favor of obviousness of the subject matter recited in
claims 1 through 5 within the meaning of 35 U.S.C. § 103(a).
ORDER
For the reasons set forth above and in the Answer, the decision of the
Examiner is affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1).

AFFIRMED

PL Initial:
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