CREE, INC.

Patent Trials and Appeals Board

Jun 16, 2021

2020004592 (P.T.A.B. Jun. 16, 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.
14/087,416 11/22/2013 Qingchun Zhang 1194-167C2 1882
27820 7590 06/16/2021
WITHROW & TERRANOVA, P.L.L.C.
106 Pinedale Springs Way
Cary, NC 27511
EXAMINER
SEFER, AHMED N
ART UNIT PAPER NUMBER
2893
NOTIFICATION DATE DELIVERY MODE
06/16/2021 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):
patents@wt-ip.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte QINGCHUN ZHANG and SEI-HYUNG RYU
Appeal 2020-004592
Application 14/087,416
Technology Center 2800
Before JEFFREY T. SMITH, BRIAN D. RANGE, and
JENNIFER R. GUPTA, Administrative Patent Judges.

GUPTA, Administrative Patent Judge.
DECISION ON APPEAL1
Pursuant to 35 U.S.C. § 134(a), Appellant2 appeals from the
Examiner’s decision to reject claims 1–20 and 22. We have jurisdiction
under 35 U.S.C. § 6(b).
We AFFIRM.

1 In this Decision, we refer to the Specification filed November 22, 2013
(“Spec.”); the Final Office Action dated April 10, 2019 (“Final Act.”); the
Appeal Brief filed January 3, 2020 (“Appeal Br.”); the Examiner’s Answer
dated April 13, 2020 (“Ans.”); and the Reply Brief filed June 1, 2020
(“Reply Br.”).
2 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42(a). Appellant identifies the real party in interest as Cree, Inc.
Appeal Br. 1.
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Application 14/087,416

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CLAIMED SUBJECT MATTER
The claims are directed to Junction Barrier Schottky (JBS) diodes
with current surge capability. Claim 1, reproduced below with emphasis to
highlight disputed limitations, is illustrative of the claimed subject matter:
1. A Schottky diode comprising:
a drift layer having a first surface with an active
region and a plurality of junction barrier element recesses,
wherein the drift layer is doped with a doping material of a first
conductivity type and a spacing between each junction barrier
element recess of the plurality of junction barrier element
recesses is less than 3 microns;
a Schottky layer on the active region and within
the plurality of junction barrier element recesses, the Schottky
layer forming a Schottky junction with respect to the active
region on the first surface; and
a plurality of first doped regions that extend into
the drift layer about corresponding ones of the plurality of
junction barrier element recesses wherein the plurality of first
doped regions are doped with a doping material of a second
conductivity type and have a doping concentration of at least
3.5 x 1019 cm-3 which is opposite the first conductivity type, and
form an array of junction barrier elements in the drift layer
below the Schottky junction, wherein the spacing between each
junction barrier element recess is configured to increase a
resistance to a current path at the spacing such that conduction
at the plurality of first doped regions adjacent to the spacing
begins at a desired level of forward current.
Appeal Br. 10 (Claims Appendix) (emphasis added).
REJECTIONS
The Examiner maintains the following rejections in the Examiner’s
Answer dated April 13, 2020:
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Application 14/087,416

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Rejection I: Claims 1–20 and 22 are rejected under pre-AIA 35 U.S.C.
§ 112, first paragraph, as failing to comply with the written description
requirement.
Rejection II: Claims 1–3, 7–10, 12, 13, 15–20, and 22 are rejected
under pre-AIA 35 U.S.C. § 103(a) as being unpatentable over Akagi.3
Rejection III: Claims 4–6, 11, 12, and 14 are rejected under pre-AIA
35 U.S.C. § 103(a) as being unpatentable over Akagi in view of Korec.4
DISCUSSION
After review of the evidence in light of the Appellant’s and the
Examiner’s opposing positions, we determine that the Appellant has not
identified reversible error in the Examiner’s rejections. Thus, we affirm the
Examiner’s rejections for the reasons expressed in the Final Office Action,
the Examiner’s Answers, and the reasons set forth below.
Rejection I – Written Description
Claim 1 requires “the plurality of first doped regions . . . have a
doping concentration of at least 3.5 x 1019 cm-3.” Appeal Br. 10 (Claims
App.). Claim 22 requires “the plurality of first doped regions have a doping
concentration in a range between about 3.5 x 1019 cm-3 to about 9.0 x 1019
cm-3.”
The Examiner rejects claim 1, and claims 2–20 and 22, which depend
therefrom, as failing to comply with the written description requirement.

3 Akagi et al., Japanese Patent Publication JP 2006-186134 A, published
July 13, 2006. We refer to the translation of record of Akagi as cited by the
Examiner.
4 Korec et al., US 2002/0125541 A1, published September 12, 2002.
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Application 14/087,416

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Final Act. 2. Specifically, the Examiner finds that the claimed range of
dopant concentrations is not supported by the originally filed disclosure. Id.
“[T]he test for [compliance with the written description requirement]
is whether the disclosure of the application relied upon reasonably conveys
to those skilled in the art that the inventor had possession of the claimed
subject matter as of the filing date.” Ariad Pharm., Inc. v. Eli Lilly & Co.,
598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc).
Claim 1
Appellant argues that the claimed dopant range is supported by
paragraph 82 of the originally filed Specification. Appeal Br. 5. The cited
portion describes a process step in forming the first doped regions, and some
of the parameters used in this step. Spec. ¶ 82. Appellant argues that one of
ordinary skill in the art would have understood this disclosure as teaching
the claimed dopant concentration, and therefore this paragraph inherently
supports the rejected claims. Appeal Br. 5–6. Appellant further argues that
the Declaration under 37 C.F.R. § 1.132 of one of the inventors, Dr. Sei-
Hyung Ryu (“Ryu Declaration”), dated February 27, 2018, provides
evidence of the relationship between the disclosed process step and the
claimed dopant concentration. Id.
Appellant’s arguments are not persuasive of reversible error. The
Specification makes no mention of a doping concentration range, nor has
Appellant provided sufficient factual evidence that demonstrates the
relationship between the disclosed process step and the claimed doping
concentration range. Without such support, there is nothing within the
originally filed disclosure that reasonably conveys any specific
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concentration range of the first doped regions to those of ordinary skill in the
art. Moreover, even if the disclosure of paragraph 82 were to provide
adequate support for a specified concentration, which we do not find, the
disclosure would fail to support the entirety of the unbounded range of “at
least 3.5 x 1019 cm-3” as claimed. Based on Appellant’s arguments, and the
Ryu Declaration, such a range without an upper limit reads on embodiments
outside the scope of the process steps set forth in the Specification. In
re Wertheim, 541 F.2d 257, 262–264 (CCPA 1976) (finding unbounded
ranges that read on embodiments outside of a supported range do not meet
the written description requirement).
Claim 22
Although claim 22 requires a bounded, more narrow doping
concentration range than the doping concentration range in claim 1, we are
also unpersuaded that the written description of the process step in paragraph
82 of Appellant’s Specification adequately supports claim 22. On the record
before us, there is insufficient factual evidence to support Appellant’s
argument that one of ordinary skill in the art would understand the
discussion of the process step as resulting in the range of concentrations
specified in the claim. Absent such evidence, a disclosure that demonstrates
only that the first regions are doped, generally, using a particular range of
process parameters does not support a claim directed to a specific, carved-
out range of concentrations.
In view of the foregoing, we sustain the Examiner’s rejection of
claims 1–20 and 22 under pre-AIA 35 U.S.C. § 112, first paragraph.
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Rejection II – Obviousness over Akagi
The Examiner rejects claims 1–3, 7–10, 12–13, 15–20, and 22 under
pre-AIA 35 U.S.C. § 103(a) as being obvious over Akagi. Final Act. 3–8.
Appellant presents arguments directed to independent claim 1 only, to
which we accordingly limit our discussion. Appeal Br. 6–8; 37 C.F.R.
§ 41.37(c)(1)(iv) (2019).
The Examiner finds that Akagi teaches all of claim 1’s limitations
except the “spacing between each junction barrier element recesses . . . is
less than 3 microns,” and the “doping concentration of at least 3.5 x 1019 cm-
3.” Final Act. 3. The Examiner, however, determines that, it would have
been obvious to one of ordinary skill in the art at the time of invention to
optimize, through routine experimentation, the spacing and doping
concentration parameters and arrive at the ranges recited in claim 1. Id. at 3–
4.
Appellant argues that it would not have been obvious to one of
ordinary skill in the art to arrive at the claimed spacing and concentration by
optimization. Appeal Br. 6–7. Specifically, Appellant first argues that Akagi
does not establish that the spacing between junction barrier element recesses
is a result-effective variable, and thus the Examiner has not provided a
“teaching, suggestion, or motivation” to arrive at the claimed spacing.
Appeal Br. 7.
Appellant’s argument is not persuasive of reversible error. The
Examiner finds recesses 3 of Akagi teach claim 1’s junction barrier element
recesses. Final Act. 3. Akagi teaches a distance between the recesses “may
be appropriately selected according to required characteristics in device
design.” Akagi, ¶ 33. Thus, contrary to Appellant’s argument, Akagi teaches
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that the spacing of the recesses impacts the characteristics of the device and
is a result-effective variable. In re Applied Materials, Inc., 692 F.3d 1289,
1297 (Fed. Cir. 2012) (“A recognition in the prior art that a property is
affected by the variable is sufficient to find the variable result-effective.”). It
is well established that the optimization of result-effective variables through
routine experimentation would have been obvious to one with ordinary skill
in the art. See Applied Materials, 692 F.3d at 1295.
Appellant argues that “conventional design principles” and Akagi
teach away from the providing the claimed spacing and doping
concentration. Appeal Br. 7; Reply Br. 3–4.
Appellant’s argument does not identify reversible error in the
Examiner’s rejection because Appellant fails to persuasively identify any
disclosure in Akagi that criticizes, discredits, or otherwise discourages a
spacing of less than 3 microns between junction barrier element recesses or a
doping concentration of at least 3.5 x 1019 cm-3. See In re Fulton, 391 F.3d
1195, 1201 (Fed. Cir. 2004) (explaining that a reference teaches away when
it criticizes, discredits, or otherwise discourages the claimed solution).
Appellant also argues that the Specification, for example at paragraph
77, establishes the “critical nature” of the spacing and the doping
concentration. Appeal Br. 7. We, however, agree with the Examiner that
there is insufficient evidence in the Specification to establish the criticality
of either parameter. Ans. 5. The cited portion of the Specification discusses
the spacing and its potential effect on a desired voltage drop. Spec. ¶¶ 77–
78. This general discussion of the spacing parameter, however, is
insufficient to establish the criticality of the spacing range recited in claim 1.
In re Hill, 284 F.2d 955, 959 (CCPA 1960) (explaining that a sufficient
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number of tests both inside and outside the claimed range should have been
presented to show the criticality of the claimed range). Thus, based on the
record before us a whole, Appellant’s argument of critical does not weigh
against the evidence of obviousness.
Finally, Appellant argues that Akagi does not disclose a doping
concentration, but rather teaches a dose for implanting ions. Appeal Br. 8.
Appellant contends that it would require undue, rather than routine
experimentation, to arrive at the claimed concentration by modifying the
dosage. Id.
Appellant’s argument is not persuasive of reversible error. The Akagi
translation expressly discloses “the concentration of the P-type
semiconductor region 4 . . . is 1 x 1018 cm-3 to 1 x Ion Implantation . . . .” Id.
A review of the original Japanese disclosure, however, reveals a range with
1 x 1018 cm-3 at the bottom end and 1 x 1019 cm-3 at the upper end.
Nevertheless, even without determining whether “1 x 1019 cm-3” refers to a
concentration or dosage, Akagi at least discloses a dopant concentration of 1
x 1018 cm-3 for the region in question. Akagi ¶ 34. Akagi further teaches that
the dopant concentration helps achieve ohmic contact with the Schottky
barrier film, and is thus a result-effective variable. Id. As such, Appellant’s
argument that Akagi fails to teach a concentration to be optimized does not
identify reversible error in the Examiner’s rejection, and the optimization of
the result-effective dopant concentration would have been obvious for the
reasons set forth by the Examiner in the rejection and Answer.
In view of the foregoing, we sustain the Examiner’s rejection of
claims 1–3, 7–10, 12–13, 15–20, and 22 under pre-AIA 35 U.S.C. § 103(a)
as obvious over Akagi.
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Application 14/087,416

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Rejection III – Obviousness over Akagi and Korec
The Examiner rejects claims 4–6, 11–12, and 14 under pre-AIA
35 U.S.C. § 103(a) as being unpatentable over Akagi in view of Korec.
Because Appellant, Appeal Br. 8–9, does not present any separate,
substantive arguments regarding this rejection, we sustain the rejection for
the reasons presented above.
CONCLUSION
We affirm the Examiner’s rejections of claims 1–20 and 22 under pre-
AIA 35 U.S.C. § 112, first paragraph, and under pre-AIA 35 U.S.C.
§ 103(a).
DECISION SUMMARY
In summary:
Claims
Rejected
35
U.S.C. §
Reference(s)/Basis Affirmed Reversed
1–20, 22 112 Written Description 1–20, 22
1–3, 7–10,
12–13, 15–20,
22
103(a) Akagi 1–3, 7–10,
12–13, 15–
20, 22

4–6, 11–12,
14
103(a) Akagi, Korec 4–6, 11–12,
14

Overall
Outcome
1–20, 22

TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv).
Appeal 2020-004592
Application 14/087,416

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AFFIRMED