Ex Parte Takami et al

Patent Trial and Appeal Board

Nov 28, 2017

13788216 (P.T.A.B. Nov. 28, 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.
13/788,216 03/07/2013 Nagisa TAKAMI 413115US2 1066
22850 7590 11/30/2017
OBLON, MCCLELLAND, MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA, VA 22314
EXAMINER
PATERSON, BRIGITTE A
ART UNIT PAPER NUMBER
2812
NOTIFICATION DATE DELIVERY MODE
11/30/2017 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
patentdocket @ oblon. com
oblonpat @ oblon. com
tfarrell@oblon.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte NAGISA TAKAMI, YOSHIHIRO UOZUMI,
and KABUSHIKI KAISHA TOSHIBA
Appeal 2017-000189
Application 13/788,2161
Technology Center 2800
Before JEFFREY T. SMITH, BEVERLY A. FRANKLIN, and
BRIAN D. RANGE, Administrative Patent Judges.
SMITH, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
This is an appeal under 35 U.S.C. § 134 from the final rejection of
claims 1—16 and 21—24. We have jurisdiction under 35 U.S.C. § 6.
We reverse.
Appellants’ invention relates generally to etching semiconductor
products. (Spec. Tflf 2-4). In particular, the invention relates to a chemical
1 According to Appellants, the real party in interest is Kabushiki Kaisha
Toshiba. See App. Br. 2.
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Application 13/788,216
solution having an improved tungsten etching rate. (Id. ). Claim 1 is
illustrative of the subject matter on appeal:
1. An etching method, comprising:
performing etching on a material having tungsten (W) as a main
component by applying as an etchant a chemical solution
comprising hydrogen peroxide as a main component to said
material, the chemical solution further comprising 12 ppm or
more and 100,000 ppm or less of W,
wherein said process provides an etching rate of said material
having tungsten as a main component that is faster than an
etching rate provided by an otherwise identical chemical
solution not comprising tungsten.
Claims Appendix to App. Br.
Appellants (see App. Br., generally) request review of the following
rejections under 35 U.S.C. § 103(a):
I. Claims 1—4, 8—13, and 21—24 rejected as unpatentable over
the combined teachings of Wu (US 5,899,738; May 4, 1999)
further in view of Smith (US 2002/0127864 Al; Sept. 12,
2002) further in view of Mayer (US 2011/0056913 Al; Mar.
10,2011). (Final Act. 2)
II. Claims 5—7 and 14—16 rejected as unpatentable over the
combined teachings of Wu, Smith, and Mayer in view of
Bogart (US 2004 /0140287 Al; July 22, 2004). (Final Act.
8)
III. Claims 1—2, 8—13, and 21—24 rejected as unpatentable over
the combined teachings of Smith and Mayer. (Final Act. 11)
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Application 13/788,216
The complete statement of the rejections on appeal appear in
the Final Office Action. (Final Act. 2—16.)
OPINION
Rejection 12
After consideration the evidence in this appeal record in light of the
respective positions advanced by the Examiner and Appellants, we
determine that Appellants have identified reversible error in the Examiner’s
determination that the subject matter recited in claims 1—4, 8—13, and 21
would have been obvious to one of ordinary skill in the art within the
meaning of 35 U.S.C. § 103(a). Accordingly, we reverse Rejection I.
The Examiner found Wu teaches an etching method, comprising
performing etching on a material having tungsten (W) as a main component
by applying an etchant (FIGs. 12A—12B, Col. 7,11. 23—41). The Examiner
recognized Wu did not teach that the etchant is a chemical solution
comprising hydrogen peroxide as a main component. (Final Act. 3). The
Examiner found Smith teaches using a chemical solution containing
hydrogen peroxide to etch a layer of tungsten. (Final Act. 3, Smith 129).
The Examiner determined it would have been obvious to add the chemical
etchant including hydrogen peroxide as described by Smith to etch the
tungsten layer of Wu. The Examiner reasons that the addition of hydrogen
peroxide would have provided the predictable result of etching tungsten.
(Final Act. 3). The Examiner found Wu did not teach the chemical etch
solution containing 12 ppm or more and 100,000 ppm or less of tungsten.
2 Our discussion applies to independent claim 1.
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Application 13/788,216
(Final Act. 4). The Examiner further determined it would have been obvious
to add the invention of Mayer to the combined invention of Wu and Smith
so as to include a hydrogen peroxide solution containing metal contaminants
that has an etched metal ion concentration of 12 ppm—100,000 ppm. (Final
Act. 5). The Examiner specifically reasons:
Mayer teaches a generic method of chemically etching a metal from a
surface using a hydrogen peroxide based etchant, measuring the
amount of ions from the etched metal in the used etching solution,
reducing the amount of metal ions in the used etching solution to
below 200 ppm and reusing the etching solution ([0028—0029]).
Mayer teaches that the used etching solution is analyzed using
analyzer 630 before being fed back to the etching chamber to be used
in etching the metal layer ([0028—0055]). While Mayer etches copper
using the hydrogen peroxide chemical etching solution, as an
example, Smith has already shown that hydrogen peroxide etching
solution is used to etch tungsten. One of ordinary skill in the art, with
the benefit of Mayer, would have found it obvious to apply this
recycling of the same chemical etchant to a metal tungsten film
hydrogen peroxide etches both copper and tungsten. Mayer does not
explicitly teach that the recycled etchant has a higher etching rate than
hydrogen peroxide containing no tungsten however, Mayer does teach
using hydrogen peroxide with less than 200 ppm of contaminants in
order to perform an etching step of a material. “[T]he discovery of a
previously unappreciated property of a prior art composition, or of a
scientific explanation for the prior art’s functioning, does not render
the old composition patentably new to the discoverer.” Atlas Powder
Co. v. Ireco Inc., 190F.3d 1342, 1347, 51 USPQ2d 1943, 1947 (Fed.
Cir. 1999). Thus the claiming of a new use, new function or unknown
property which is inherently present in the prior art does not
necessarily make the claim patentable. In re Best, 562 F.2d 1252,
1254, 195 USPQ 430, 433 (CCPA 1977). (MPEP [§] 2112 (I)).
(Final Act. 4—5).
Appellants argue the teachings of Mayer regarding the etching of
copper utilizing an etchant containing copper is not suggestive of, nor
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Application 13/788,216
predictive of the effects of, the use of tungsten in an etchant for etching of
material having tungsten as a main component as required by the claimed
invention. (App. Br. 4). Thus, Appellants disagree with the Examiner’s
position that Mayer would have suggested, when etching tungsten, recycling
the hydrogen peroxide etchant having less than 200 ppm of contaminants.
(App. Br. 4). Appellants rely on the Declarations of Uozumi in further
support of their arguments.3 (App. Br. 3). Appellants argue the first
Uozumi Declaration explains the different etching reaction rates of copper
and tungsten utilizing an etchant containing hydrogen peroxide. (App. Br. 4;
Decl. 11 5). Declarant Uozumi believes the different etch rates is a result of
the differences in pH. (App. Br. 4; Decl. I Tflf 5, 6). Appellants argue the
Figure 2B of the present application and the second Uozumi Declaration
establishes the tungsten etching rate of a tungsten-containing hydrogen
peroxide solution is superior to the etching rate of a tungsten-free hydrogen
peroxide solution. (App. Br. 6—8; Decl. II 5—10).
In response to Appellants’ arguments and evidence, the Examiner
states “the claimed invention merely teaches reusing an etchant solution that
has been contaminated with the metal particles of the metal said solution is
being used to etch.” (Ans. 2). The Examiner further responds that Mayer
was cited to teach that chemically etching metal substrates with a hydrogen
peroxide etchant will result in contamination of metal particles in the etchant
solution which can be recycled for further etching. (Ans. 3). The Examiner
further contends that Mayer’s disclosure that an etchant containing less than
200 ppm of metal particle contaminants would have suggested the amount of
3 Declaration I, filed August 31, 2015 and Declaration II, filed December 28,
2015.
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Application 13/788,216
tungsten present in the etchant required by the claimed invention. (Ans. 3).
The Examiner asserts Mayer was cited for the purpose of suggesting the
suitability of recycling the hydrogen peroxide etchant solution of Smith.
(Ans. 6). According to the Examiner, the content of the Uozumi
Declarations is not directed to the appealed rejection and does not address
the concept of recycling hydrogen peroxide and metal etching processes.
(Ans. 5—6).
We agree with Appellants that the Examiner’s rejection of the
independent claim 1 is not well-founded. The Examiner has not adequately
explained why a person of ordinary skill in the art would have utilized the
solution etching techniques of Smith along with the gas etching techniques
of Wu. The Examiner has not adequately explained what conditions are
necessary in Smith to result in a recycled hydrogen peroxide containing
etchant having tungsten in the amount of more than 12 ppm to less than
100,000 ppm as required by the claimed invention. The Appellants have
argued and presented Declarations that provide technical reasoning why a
person of ordinary skill in the art would not have looked to the teachings of
etching copper as described by Mayer for etching tungsten. The Uozumi
Declarations have presented technical explanation that the reaction
mechanism a hydrogen peroxide etchant with copper and tungsten and the
resulting pH of the etchant solutions are not similar. The Examiner has not
provided an adequate technical explanation supported by evidence to rebut
Uozumi Declarations and Appellants’ arguments. The Examiner’s rejection
does not establish that the claimed invention is the new use, new function or
unknown property which was inherently present in the cited prior art. Thus
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the Examiner’s citation of Atlas Powder and Best are insufficient to support
appealed rejection.
Rejection II
The Examiner’s additional reliance on Bogart in rejecting dependent
claims 5—7 and 14—16 neither addresses nor cures the deficiency noted above
in connection with Rejection I. Accordingly, we do not sustain Rejection II
for the reasons given in connection with Rejection I.
Rejection III
This rejection differs from Rejection I by not including a citation to
Wu. As explained in our discussion above, we determine that the
combination of Smith and Mayer was insufficient to establish the
obviousness of independent claim 1. The exclusion of Wu from the
statement of the rejection does not remedy the deficiencies we previously
discussed. Accordingly, we do not sustain Rejection III for the reasons
given in connection with Rejection I.
Thus, the Examiner has not established that the relied-upon
disclosures of Smith, Mayer, and/or Wu are sufficient to support
obviousness of independent claim 1. See In re Warner, 379 F.2d 1011, 1017
(CCPA 1967) (“A rejection based on section 103 clearly must rest on a
factual basis, and these facts must be interpreted without hindsight
reconstruction of the invention from the prior art”). Therefore, we reverse
the rejection.
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Accordingly, we reverse the Examiner’s decision to reject claims 1—
16 and 21—24 for the reasons presented by Appellants and given above.
ORDER
The rejections of claims 1—16 and 21—24 under 35 U.S.C. § 103(a) are
reversed.
REVERSED
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