TOYO TANSO CO., LTD.

Patent Trials and Appeals Board

Dec 6, 2021

2021001920 (P.T.A.B. Dec. 6, 2021)

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.
15/360,498 11/23/2016 Satoshi Torimi P161066US00 8812
38834 7590 12/06/2021
WESTERMAN, HATTORI, DANIELS & ADRIAN, LLP
8500 LEESBURG PIKE
SUITE 7500
TYSONS, VA 22182
EXAMINER
LI, MEIYA
ART UNIT PAPER NUMBER
2811
NOTIFICATION DATE DELIVERY MODE
12/06/2021 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):
patentmail@whda.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte SATOSHI TORIMI, MASATO SHINOHARA,
YOUJI TERAMOTO, NORIHITO YABUKI, SATORU NOGAMI, and
MAKOTO KITABATAKE1
____________

Appeal 2021-001920
Application 15/360,498
Technology Center 2800
____________

Before ADRIENE LEPIANE HANLON, CHRISTOPHER C. KENNEDY,
and SHELDON M. MCGEE, Administrative Patent Judges.

KENNEDY, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134(a) from the Examiner’s
decision rejecting claims 13–15. We have jurisdiction under 35 U.S.C.
§ 6(b). We AFFIRM.
BACKGROUND
The subject matter on appeal relates to silicon carbide (SiC) wafers.
E.g., Spec. ¶ 1; Claim 13. Claim 13 is reproduced below from Appendix A

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. The Appellant identifies the real party in interest as
TOYO TANSO CO., LTD. Appeal Br. 2.
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of the Appeal Brief:
13. A SiC (silicon carbide) wafer, comprising:
a mark showing information on a first surface of a SiC substrate,
said information being conveyed by a removed portion formed
into a predetermined shape on the SiC substrate, wherein the
mark is on C-face/(000-1) plane, and
a central region of the SiC wafer having a maximum thickness of
100 μm to 50 μm, wherein at least the first surface of the SiC
substrate is single crystal SiC, wherein the central region
comprises a majority of the SiC wafer.
REJECTIONS ON APPEAL
The claims stand rejected under 35 U.S.C. § 103 as follows:
1. Claim 13 over Kondo,2 Fissel,3 and Okada4.
2. Claim 14 over Kondo, Fissel, Okada, and Yamamura5.
3. Claim 15 over Kondo, Fissel, Okada, and Reddy6.

2 US 2014/0017447 A1 (published Jan. 16, 2014).
3 A. Fissel et al., Epitaxial growth of SiC thin films on Si-stabilized α-
SiC(0001) at low temperatures by solid-source molecular beam epitaxy, 154
J. Crystal Growth 72 (1995).
4 Yu Okada et al., Thinning of a two-inch silicon carbide wafer by plasma
chemical vaporization machining using a slit electrode, 778 Materials Sci.
Forum 750 (2014).
5 K. Yamamura et al., Plasma assisted polishing of single crystal SiC for
obtaining atomically flat strain-free surface, 60 CIRP Annals —
Manufacturing Technology 571 (2011).
6 Jayadeep Deva Reddy et al., Mechanical Properties of 3C-SiC Films for
MEMS Applications, 1049 Mater. Res. Soc. Symp. Proc. (2008).
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ANALYSIS
The Appellant argues the claims as a group. We select claim 13 as
representative, and the remaining claims will stand or fall with claim 13,
from which they depend.
After review of the cited evidence in the appeal record and the
opposing positions of the Appellant and the Examiner, we determine that the
Appellant has not identified reversible error in the Examiner’s rejection of
claim 13. Accordingly, we affirm the rejection for reasons set forth below,
in the Final Rejection dated November 29, 2019, and in the Examiner’s
Answer.
The Examiner finds that Kondo discloses an SiC wafer within the
scope of claim 13 except that “Kondo does not disclose the mark is on C-
face/(000-1) plane, the thickness is a maximum thickness of 100 µm to 50
µm.” Final Act. 3. The Examiner finds that Fissel teaches “in related text
an epitaxial layer grown on a SiC(0001) substrate,” and that Okada teaches
SiC wafers with “maximum thickness of 100 µm to 50 µm.” Id. The
Examiner determines that it would have been obvious “to grow an epitaxial
layer on a SiC(0001) substrate, as taught by [Fissel], and include a
maximum thickness of 100 µm to 50 µm, as taught by [Okada], in Kondo’s
device, in order to allow easier fabrication of high-quality epitaxial surfaces,
reduce cost of the device and reduce the on-resistance in vertical devices and
improve the performance of the device.” Id. at 4.
The Examiner also finds that “where the[] general conditions of a
claim are disclosed in the prior art, discovering the optimum or workable
ranges involves only routine skill in the art.” Id. (citing In re Aller, 220 F.2d
454, 456 (CCPA 1955)). The Examiner observes that the application on
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appeal does not attribute criticality or unexpected results to the thickness
range recited by claim 13. Id.
The Appellant argues that a wafer within the scope of claim 13 could
not be obtained using Okada’s wafer thinning method (which involves the
use of plasma chemical vaporization machining (CVM)) because the wafer
would crack. Appeal Br. 8.
That argument is unpersuasive. The Examiner does not propose the
use of Okada’s method to achieve the recited thickness; the Examiner relies
on Okada only to establish that wafer thicknesses within the recited range
were known desirable thicknesses for SiC wafers. See Final Act. 3–4. The
Examiner relies on Fissel in proposing that such wafer thickness could be
achieved by epitaxial growth. See id. The Appellant provides no persuasive
reason to believe that a layer formed by epitaxial growth and marked by
laser as taught by Kondo (¶ 51) would crack, particularly given that post-
marking polishing steps in Kondo appear to be optional. See Kondo ¶¶ 51,
73 (“[W]hen necessary, mechanical polishing is performed . . . .” (emphasis
added)).
The Appellant appears to acknowledge that rationale and argues that it
is “clear error to assert that the skilled artisan would find it obvious to derive
the invention as claimed based on the mere disclosure of an epitaxial layer as
taught by Fissel in combination with Kondo in view of Okada” for reasons
“reproduced above.” Appeal Br. 8. That argument is unpersuasive because
it amounts to little more than mere disagreement with the Examiner’s
rationale. See SmithKline Beecham Corp. v. Apotex Corp., 439 F.3d 1312,
1320 (Fed. Cir. 2006) (“[M]ere statements of disagreement . . . as to the
existence of factual disputes do not amount to a developed argument.”). The
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Examiner proposes known methods (e.g., Fissel’s) to achieve a known
suitable wafer thickness (e.g., Okada’s) for SiC wafers. The use of known
elements according to their established functions typically does not result in
nonobvious subject matter. See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398,
416–21 (2007) (“The combination of familiar elements according to known
methods is likely to be obvious when it does no more than yield predictable
results.”); see also id. at 416 (“[W]hen a patent claims a structure already
known in the prior art that is altered by the mere substitution of one element
for another known in the field, the combination must do more than yield a
predictable result.”).
The Appellant’s arguments concerning wafer cracking rely only on
paragraphs 4 and 61 of the Specification for support. See Appeal Br. 6.7
Neither of those paragraphs establish that cracking occurs in the processes of
the prior art relied upon by the Examiner. Paragraph 57 of the Specification
states that cracking “may” occur using certain prior art methods that involve
mechanical polishing, and that it is “difficult to manufacture” thin wafers
using “conventional method[s].” Spec. ¶ 57. As noted above, the method of
the combined prior art proposed by the Examiner does not appear to require

7 We are aware that the file history of the application on appeal includes a
Declaration from Satoshi Torimi. See Declaration dated August 22, 2018
(“Decl.”). However, although the file history includes a date on which the
Declaration apparently was provided to the Office, the Declaration itself is
neither signed nor dated. See Decl. Moreover, the Appellant does not cite
or otherwise rely on that Declaration in this appeal. Cf. MPEP § 1205.02
(“[T]he [appeal] brief should not incorporate or reference previous
responses.”). We, therefore, do not consider the Torimi Declaration or the
Appellant’s previous responses to office actions in deciding this appeal. See
id.
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mechanical polishing. Moreover, that something “may” happen, or that
achieving a thin wafer with conventional methods is “difficult,” does not
indicate reversible error in the Examiner’s rejection.
Finally, we observe that the Appellant does not address or otherwise
contest the Examiner’s determination that, absent criticality or unexpected
results, the recited wafer thickness fails to patentably distinguish the subject
matter of claim 13 from the subject matter of the combined prior art.
On this record, we are not persuaded of reversible error in the
Examiner’s rejection of claim 13. See In re Jung, 637 F.3d 1356, 1365 (Fed.
Cir. 2011) (“[I]t has long been the Board’s practice to require an applicant to
identify the alleged error in the examiner’s rejections . . . .”).
CONCLUSION
In summary:
Claim
Rejected
35 U.S.C.
§ References Affirmed Reversed
13 103 Kondo, Fissel, Okada 13
14 103 Kondo, Fissel, Okada, Yamamura 14
15 103 Kondo, Fissel, Okada, Reddy 15
Overall
Outcome 13–15
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