Ex Parte Lebouitz et al

Patent Trial and Appeal Board

Apr 18, 2017

13512634 (P.T.A.B. Apr. 18, 2017)

United States Patent and Trademark Office
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O.Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
13/512,634 05/30/2012 Kyle S. Lebouitz 33495-0006 9741
26587 7590 04/19/2017
MCNEES WALLACE & NURICK LLC
100 PINE STREET
P.O. BOX 1166
HARRISBURG, PA 17108-1166
EXAMINER
REMAVEGE, CHRISTOPHER
ART UNIT PAPER NUMBER
1713
MAIL DATE DELIVERY MODE
04/19/2017 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte KYLE S. LEBOUITZ, ANDREW DAVID JOHNSON,
EUGENE KARWACKI JR., SUHAS NARAYAN KETKAR,
JOHN NEUMANN, and DAVID L. SPRINGER
Appeal 2015-007270
Application 13/512,634
Technology Center 1700
Before TERRY J. OWENS, JAMES C. HOUSEL, and
JEFFREY R. SNAY, Administrative Patent Judges.
HOUSEL, Administrative Patent Judge.
DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellants1 appeal from the
Examiner’s decision finally rejecting claims 1—4, 9-12, 17, 18, 20, and 21.
We have jurisdiction over the appeal under 35 U.S.C. § 6(b).
We AFFIRM.2
1 According to Appellants, the real party in interest is SPTS
TECHNOLOGIES LIMITED. Br. 1.
2 Our decision refers to the Specification (Spec.) filed May 30, 2012, the
Examiner’s Final Office Action mailed May 19, 2014, Appellants’ Appeal
Brief (Br.) filed November 13, 2014, and the Examiner’s Answer (Ans.)
mailed June 4, 2015.
Appeal 2015-007270
Application 13/512,634
STATEMENT OF THE CASE
The invention relates to a process for vapor etching semiconductor
materials and substrates with improved selectivity, which is the ratio of
etching the material to be etched versus those materials that are intended to
remain, i.e., not be etched. Spec. Tflf 8—9. Appellants disclose adding
oxygen provides a selectivity benefit in the etching process. Id. 112.
Further, Appellants contemplate mixtures of gases which include oxygen or
are used in place of oxygen to obtain this selectivity benefit, including
nitrous oxide, ozone, oxygen atoms, nitrogen dioxide, and carbon dioxide.
Id. Appellants disclose a number of ways in which such gases including
oxygen may be incorporated into the vapor etching process to provide
improved selectivity including pulse cycling with a mixture of an etchant
and the gas, etching with the etchant followed by flushing with the gas, and
continuous etching with a mixture of the etchant and the gas. Id. 111.
Claim 1, reproduced below from the Claims Appendix to the Appeal
Brief, is illustrative of the subject matter on appeal.
1. A vapor etching method comprising:
(a) placing a material to be etched and an etch resistant
material into an etching chamber;
(b) following step (a), adjusting a pressure in the etching
chamber to a desired pressure; and
(c) following step (b), exposing the materials in the
etching chamber to an etching gas and to an amount of a gas
that comprises oxygen that is selected to obtain a desired
selectively ratio of a change in the material to be etched caused
by said exposure over a change in the etch resistant material
caused by said exposure, wherein step (c) includes sequentially
exposing the materials to (1) the etching gas absent the gas that
comprises oxygen and (2) to the gas that comprises oxygen
absent the etching gas.
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REJECTIONS
The Examiner maintains, and Appellants request our review of, the
following grounds of rejection under 35 U.S.C. § 103(a):
1. Claims 1—4, 9, 11, 12, 17, 18, 20, and 21 as unpatentable over
Yan3 in view of Floyd;4 and
2. Claims 1 and 10 as unpatentable over Yan in view of Huibers.5
ANALYSIS
After review of the opposing positions articulated by Appellants and
the Examiner, the applied prior art, and Appellants’ claims and Specification
disclosures, we determine that the Appellants’ arguments are insufficient to
identity reversible error in the Examiner’s obviousness rejections over the
combinations of Yan with either Floyd or Huibers. In re Jung, 637 F.3d
1356, 1365 (Fed. Cir. 2011). Accordingly, we affirm the stated obviousness
rejections for substantially the fact findings and the reasons set forth by the
Examiner in the Examiner’s Answer and the Final Office Action. We offer
the following for emphasis.
Rejection 1
Appellants do not argue the claims separately, instead focusing on the
limitations of independent claims 1 and 17. Br. 4—9. Further, Appellants’
arguments do not distinguish between these independent claims. Thus, we
select claim 1 as representative for resolving the issues on appeal. The
3 Yan et al., US 2008/0032439 Al, published February 7, 2008 (hereinafter
“Yan”).
4 Floyd et al., US 2009/0071932 Al, published March 19, 2009 (hereinafter
“Floyd”).
5 Huibers et al., US 7,362,494 B2, issued April 22, 2008 (hereinafter
“Huibers”).
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remaining claims stand or fall with claim 1. 37 C.F.R. § 41.37 (c)(l)(iv)
(2014).
The Examiner finds Yan teaches a vapor etching method comprising
each of the steps as recited in claim 1 except for sequential exposure of the
materials to the etchant absent the gas that comprises oxygen followed by
the gas that comprises oxygen absent the etchant. Final Act. 4—5. The
Examiner also finds Yan teaches an etching selectivity of the etchant alone
without a co-etchant may be up to at least 500:1. Id. Therefore, the
Examiner concludes that the ordinary artisan would reasonably have
expected that performing the etching process with the etchant absent a co­
etchant would have successfully achieved high selectivity. Id.
Moreover, the Examiner finds Yan teaches that purging between
etching cycles removes reactive etching byproducts and intermediates,
thereby improving selectivity. Id. However, Yan does not specify the purge
gas. Id. at 4. For this feature, the Examiner finds Floyd teaches etching
processes that utilize an etchant purge between etching cycles, wherein the
purge gas may be carbon dioxide. Id. at 5. The Examiner concludes that it
would have been obvious to use carbon dioxide as the purge gas in Yan’s
process in order to remove etching byproducts and intermediates from the
etching chamber as taught by Floyd, thereby improving selectivity. Id. at 6.
Appellants contend that the combination of Yan and Floyd fails to
disclose or suggest step (c) of claim 1, in particular, either sequentially
exposing the materials to the etching gas in the absence of the gas that
comprises oxygen and to the gas that comprises oxygen in the absence of the
etching gas (or steps (b) and (c) of claim 17, particularly, separately
exposing the substrate to the etching gas and the gas comprising oxygen).
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Br. 4. In this regard, Appellants argue that, because Yan teaches that the
device to be etched is contemporaneously contacted with both the etchant
and a co-etchant, Yan does not teach sequential exposure to the etchant
followed by the co-etchant. Id. at 4—5. Appellants also argue that Yan fails
to teach that the co-etchant is present in an amount effective to improve
etching selectivity. Id. at 5.
However, these arguments fail to address the Examiner’s finding
regarding Yan’s teaching that the co-etchant, while useful for improving
etching selectivity, is not required. See Ans. 5, citing Yan | 83 (“an etching
selectivity between the target material and the structural material in the
absence of a co-etchant is at least 20:1” and may be “at least 500:1”). In
addition, these arguments misapprehend the Examiner’s rejection which is
not based on Yan’s use of the co-etchant or modifying Yan’s process to
separately etch with the etchant and co-etchant. Instead, the Examiner’s
rejection is based on the use of Floyd’s purge gas, carbon dioxide, in Yan’s
process for purging the etchant between etching cycles.
In this regard, Appellants additionally argue that the claims do not
relate to purging with carbon dioxide. Br. 7. Appellants urge that the gas
that comprises oxygen is not used to purge the chamber after the etching gas
has been introduced, but instead is there to improve the selectivity of the
etching gas. Id. Appellants further argue that Floyd fails to teach or suggest
that the purge gas has the effect of a co-etchant or is in an amount selected to
obtain a desired selectivity ratio of change in the material to be etched. Id. at
8. Moreover, Appellants argue that because Floyd’s purge gas pushes
process gases through the system, the purge gas and the process gases are
both present simultaneously and are not delivered sequentially. Id.
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“[A]s an initial matter, the PTO applies to the verbiage of the
proposed claims the broadest reasonable meaning of the words in their
ordinary usage as they would be understood by one of ordinary skill in the
art, taking into account whatever enlightenment by way of definitions or
otherwise that may be afforded by the written description contained in the
applicant’s specification.” In re Morris, 127 F.3d 1048, 1054 (Fed. Cir.
1997). The Examiner’s rejection relies on Floyd’s carbon dioxide purge gas
as the “gas that comprises oxygen” recited in claim 1. Final Act 5—6.
Appellants do not dispute that carbon dioxide is a gas that comprises
oxygen. Instead, Appellants dispute the Examiner’s finding that Floyd’s
carbon dioxide purge gas is used in “an amount. . . that is selected to obtain
a desired selectivity ratio of a change in the material to be etched caused by
said exposure over a change in the etch resistant material caused by said
exposure” because Floyd does not attribute any etch function to the carbon
dioxide.
However, claim 1, rather than requiring that the gas that comprises
oxygen itself perform any etching per se, merely requires that the gas that
comprises oxygen is selected to obtain a desired etching selectivity ratio.
We note Appellants disclose that the selectivity benefit of adding oxygen is
shown for the scenario of etching using pulses of xenon fluoride in etching
cycles with oxygen flushing between each cycle. Spec. 111. Appellants
further disclose that mixtures of gases which include oxygen as well as other
oxidizing gases, including carbon dioxide, are contemplated. Id. 112. In
addition, Appellants disclose that a “flush of gas between etch cycles can
also be incorporated ... by introducing an oxygen or oxygen mixture.” Id. 1
62. Finally, we note that Appellants describe an example wherein the use of
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an oxygen flush gas between pure xenon difluoride etching cycles improved
the Selectivity Ratio. Id. H 94—96.
Based on these disclosures, we determine that the scope of claim 1
includes carbon dioxide as the claimed gas that comprises oxygen, used as a
purge or flush that improves the selectivity ratio, contrary to Appellants’
argument otherwise. As such, the Examiner’s finding that Floyd’s carbon
dioxide purge inherently improves the selectivity of the xenon difluoride
etching process is likewise supported by the record. As to the recited “in an
amount” in the claim recitation at issue, we note that Appellants fail to
identify any criticality in the amount of the purge gas used in the disclosed
process. In this regard, Appellants do not direct our attention to any
disclosure, nor do we find any, of any specific amount of the gas that
comprises oxygen that is used in the purging or flushing of the etching
chamber between etching cycles with pure xenon difluoride.
Appellants further argue that because claim 1 recites “an amount of a
gas that comprises oxygen that is selected to obtain a desired selectivity
ratio,” the Examiner erred in finding that the claims do not require that the
gas that comprises oxygen improves selectivity of etching gases generated in
situ. We note Appellants disclose that the concept of adding oxygen (or
other gas that comprises oxygen) is believed to improve the selectivity of
xenon difluoride or other vapor phased etching gases generated in situ.
Spec. 113. Thus, while Appellants are correct that the claims include the
possibility for improved selectivity of etching gases generated in situ, the
claims do not definitively require such. Nonetheless, to the extent that
Appellants’ claims cover this possibility, such would necessarily occur in the
Examiner’s proposed modification of Yan’s process, which uses xenon
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difluoride as the etching gas and provides a purge gas between etching
cycles, with the use of Floyd’s carbon dioxide purge gas.
It follows, therefore, that Appellants have not identified reversible
error in the Examiner’s conclusion of obviousness over Yan in view of
Floyd. Accordingly, we sustain this rejection.
Rejection 2
Appellants do not argue the claims separately, instead focusing on the
limitations of independent claim 1. Br. 9—12. As such, we limit our
discussion below to claim 1. Claim 10 stands or falls with claim 1.
The Examiner finds Yan teaches a vapor etching method comprising
each of the steps as recited in claim 1 except for sequential exposure of the
materials to the etchant absent the gas that comprises oxygen followed by
the gas that comprises oxygen absent the etchant. Final Act. 9—10. The
Examiner also finds Yan teaches an etching selectivity of the etchant alone
without a co-etchant may be up to at least 500:1. Id. at 10. Therefore, the
Examiner concludes that the ordinary artisan would reasonably have
expected that performing the etching process with the etchant absent the co­
etchant would have successfully achieved high selectivity. Id.
The Examiner finds Huibers discloses a method for forming
micromirror devices by vapor phase etching that includes exposing a
material to an etchant to remove a portion of sacrificial material to expose at
least a portion of deformable hinges for the micromirrors, followed by
exposure to an oxygen-containing gas other than air followed by removal of
the remaining sacrificial material. Id. at 11. The Examiner concludes that it
would have been obvious to modify Yan’s method of forming movable
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micromirrors to include a step of oxidizing the deformable hinges by
exposing to oxygen gas after etching in order to prevent micromirror device
failure as taught by Huibers. Id.
Appellants argue that the Examiner’s combination of Yan and Huibers
fails to disclose step (c) of claim 1. Br. 9. In particular, Appellants argue
that the present invention does not relate to oxidizing hinges, nor to
addressing any problem associated with plastic deformation of these hinges.
Id. at 10. As such, Appellants urge that the purpose of the claimed invention
is completely different from that of Huibers. Id. at 10—11. Appellants
further contend that neither Yan nor Huibers teach sequential exposure to
two gases to achieve a desired selectivity. Id. Indeed, Appellants argue that
Huibers is in a different technical field to that of the invention and the
ordinary artisan would not look to Huibers to use oxygen for an entirely
different reason to arrive at the invention of claim 1. Id.
Appellants’ arguments are not persuasive of reversible error. Our
reviewing court has stated that “[t]wo separate tests define the scope of
analogous prior art: (1) whether the art is from the same field of endeavor,
regardless of the problem addressed and, (2) if the reference is not within the
field of the inventor’s endeavor, whether the reference still is reasonably
pertinent to the particular problem with which the inventor is involved.” In
re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004). While these two criteria are
helpful in many instances, we must not lose sight of the key question at
hand: what is “prior art” as that term is used in 35 U.S.C.
§ 103(a)? References that are “too remote to be treated as ‘prior art’” are
excluded from the obviousness analysis. In re Sovish, 769 F.2d 738, 741,
226 (Fed. Cir. 1985). The non-analogous art test provides helpful insight on
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the underlying question of what is “prior art” within the meaning of the
statute; we should not, however, be blind to the reality of the circumstances
of the case before us. In re Wood, 599 F.2d 1032, 1036 (CCPA 1979). Nor
should we adhere to rigid and mandatory formulas that overly limit the
inquiry. KSRInt’l Co. v. Teleflex Inc., 550 U.S. 398, 419 (2007).
Focusing on the first of the two tests above, the test for analogous art
“requires the PTO to determine the appropriate field of endeavor by
reference to explanations of the invention's subject matter in the patent
application, including the embodiments, function, and structure of the
claimed invention.” Bigio, 381 F.3d at 1325. We thus consider all
explanations of the inventors’ subject matter while keeping in mind that
prior art is analogous when it “is from the same field of endeavor,
regardless of the problem addressed.” Bigio, 381 F.3d at 1320 (emphasis
added). Thus, “field of endeavor” should not be defined narrowly based
only upon the specific problem addressed.
Moreover, when considering field of endeavor, we remain cognizant
of the adage that “the name of the game is the claim.” In re Hiniker Co.,
150 F.3d 1362, 1369 (Fed. Cir. 1998) (quoting Giles Sutherland Rich, Extent
of Protection and Interpretation of Claims—American Perspectives, 21 Inf 1
Rev. Indus. Prop. & Copyright L. 497, 499 (1990)). The Supreme Court has
articulated this same sentiment when emphasizing that the patentee’s
motivation and purpose do not control an obviousness determination:
In determining whether the subject matter of a patent claim is obvious,
neither the particular motivation nor the avowed purpose of the
patentee controls. What matters is the objective reach of the claim. If
the claim extends to what is obvious, it is invalid under § 103.
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KSR, 550 U.S. at 419.
Claim 1 broadly recites a vapor etching method. Although Appellants
argue that Huibers is in a different technical field to that of the invention,
Appellants do not challenge the Examiner’s findings that both Yan and
Huibers teach vapor etching methods. Nor do Appellants challenge the
Examiner’s findings that Yan and Huibers are both directed to a method of
forming micromirrors using vapor etching methods. Further, although the
purpose of Huibers’ use of an oxygen exposure step separate from the
etchant exposure step is different from that of Appellants, we note that the
motivation for obviousness need not be the same as that of Appellants. KSR,
550 U.S. at 419. Here, the Examiner articulates a rational basis for
modifying Yan’s method of forming micromirrors to include a separate step
of exposure to oxygen after etchant exposure, i.e., to prevent micromirror
device failure due to plastic deformation of the hinges. Final Act. 11.
Moreover, the Examiner finds that Huibers’ oxidation process demonstrably
changes the selectivity of the etching process to an oxidizing process and
inherently alters the etching selectivity of the hinges by the formed oxide.
Ans. 7. Appellants have not challenged these findings; no Reply Brief has
been filed.
Appellants additionally argue that because Huibers is silent as to the
pressure of the oxygen used to effect oxidation, Huibers fails to disclose or
suggest “adjusting a pressure in the etching chamber to a desired pressure.”
Br. 11. This argument is not persuasive because claim 1 merely requires that
the pressure is adjusted after step (a) and before step (c). Appellants do not
dispute the Examiner’s finding that Yan’s method includes a step of
adjusting the pressure in the etching chamber after placing a material to be
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etched in the chamber and before exposing the material to the etchant. Final
Act. 9. Further, the Examiner’s modification of Yan’s method in view of
Huibers provides a separate exposure to oxygen after the etchant exposure.
Id. at 11. As such, Yan’s pressure adjustment step is unmodified in the
Examiner’s proposed combination. Appellants’ argument presumes
otherwise and is therefore without merit.
It follows, therefore, that Appellants have not identified reversible
error in the Examiner’s conclusion of obviousness over Yan in view of
Huibers. Accordingly, we sustain this rejection.
DECISION
Upon consideration of the record, and for the reasons given above and
in the Final Office Action and the Answer, the decision of the Examiner
rejecting claims 1—4, 9-12, 17, 18, 20, and 21 under 35 U.S.C. § 103(a) as
unpatentable over Yan in view of Floyd or Huibers 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
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