CREE, INC.

Patent Trials and Appeals Board

Jul 22, 2020

14259821 - (D) (P.T.A.B. Jul. 22, 2020)

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.
14/259,821 04/23/2014 Qingchun Zhang 1194-200 1023
27820 7590 07/22/2020
WITHROW & TERRANOVA, P.L.L.C.
106 Pinedale Springs Way
Cary, NC 27511
EXAMINER
PIZARRO CRESPO, MARCOS D
ART UNIT PAPER NUMBER
2814
NOTIFICATION DATE DELIVERY MODE
07/22/2020 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
____________

Appeal 2019-003790
Application 14/259,821
Technology Center 2800
____________

Before ADRIENE LEPIANE HANLON, MICHAEL G. McMANUS, and
MERRELL C. CASHION, JR., Administrative Patent Judges.

CASHION, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE

Pursuant to 35 U.S.C. § 134(a), the Appellant1 appeals from a Final
Office Action rejecting claims 1–11, 13, 14, and 31–33. We have
jurisdiction under 35 U.S.C. § 6.
We AFFIRM.

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies the real party in interest as Cree, Inc.
Appeal Br. 1.
Appeal 2019-003790
Application 14/259,821

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Claim 1 is illustrative of the subject matter on appeal and is
reproduced below (formatting added):
1. An insulated gate bipolar transistor (IGBT) device
comprising:

an IGBT stack comprising:

an injector region, the injector region having a first
conductivity type and providing a first surface of the
IGBT stack;

a drift region over the injector region opposite the
first surface, the drift region having a second
conductivity type that is opposite the first conductivity
type;

a pair of junction implants in the IGBT stack along
a second surface of the IGBT stack, which is opposite the
first surface;

a junction field effect transistor (JFET) region
between the pair of junction implants along the second
surface of the IGBT stack, the JFET region having the
second conductivity type and a doping concentration that
is different from a doping concentration of the drift
region;

a spreading region between the drift region and the
JFET region, the spreading region having the second
conductivity type and a doping concentration that is
different from the doping concentration of the drift
region and the doping concentration of the JFET region;

a field termination well etched in a surface of the
JFET region opposite the drift region and between the
pair of junction implants; and

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a field termination region filling the field
termination well, the field termination region having the
first conductivity type and comprising a same material as
the drift region, the spreading region, and the JFET
region; wherein the field termination region is provided
by a first epitaxial structure and the JFET region is
provided by a second epitaxial structure that is different
from the first epitaxial structure;

a collector contact over the first surf ace; and

a gate contact and an emitter contact on the second
surface.

Appellant requests review of the following rejections from the
Examiner’s Final Office Action:
I. Claims 1–4, 7–11, 13, 14, and 31–33 rejected under 35 U.S.C.
§ 103 as unpatentable over Ryu (US 2010/0301335 A1, published December
2, 2010), Zhang (US 2010/0140628 A1, published June 10, 2010), and
Yilmaz (US 5,136,349, issued August 4, 1992).2

II. Claims 5 and 6 rejected under 35 U.S.C. § 103 as unpatentable
over Ryu, Zhang, Yilmaz, and Merrill (US 5,661,314, issued August 26,
1997).

Appellant presents arguments only for claim 1 and relies on these
arguments to address the rejection of the remaining claims. Appeal Br. 6.
We select claim 1 as representative of the subject matter on appeal and

2 Claims 31–33 were inadvertently omitted from the rejection statement.
However, the Examiner addressed these claims in the discussion of the
rejection (Final Act. 5–6) and Appellant acknowledges that the claims stand
rejected (Appeal Br. 6). We therefore find this omission to be harmless
error.
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decide the appeal as to all grounds of rejection based on the arguments
Appellant makes in support of the patentability of claim 1.

OPINION
CLAIM INTERPRETATION
As a preliminary matter, our review of the Examiner’s analysis
requires us to construe the claim 1 language “the JFET region is provided by
a second epitaxial structure that is different from the first epitaxial structure
[of the field termination region]” to define its scope and meaning. See
Gechter v. Davidson, 116 F.3d 1454, 1457 (Fed. Cir. 1997). Specifically, to
give proper weight to the evidence of record and the respective positions of
Appellant and the Examiner, we must first determine what does “different”
mean in relation to the first and second epitaxial structures. Thus, the review
of the grounds of rejection of the appealed claims necessarily entails the
interpretation of the scope of the appealed claims, giving the broadest
reasonable interpretation to the terms thereof consistent with the written
description provided in Appellant’s Specification as it would be interpreted
by one of ordinary skill in this art. See In re Morris, 127 F.3d 1048, 1054
(Fed. Cir. 1997).
Terms in the appealed claims must be given their broadest reasonable
interpretation including the ordinary meaning unless another meaning is
intended by Appellant as established in the written description of their
Specification. See, e.g., In re Zletz, 893 F.2d 319, 321–22 (Fed. Cir. 1989).
When the Specification does not contain an express definition, a reasonable,
supported interpretation of the appealed claims that differs from that urged
by applicants can be used to determine the patentability of the claims.
Morris, 127 F.3d at 1055–56 (“Absent an express definition in their
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specification, the fact that appellants can point to definitions or usages that
conform to their interpretation does not make the PTO’s definition
unreasonable when the PTO can point to other sources that support its
interpretation.”). Indeed, “[i]t is the applicants’ burden to precisely define
the invention, not the PTO’s. See 35 U.S.C. § 112 ¶ 2 [statute omitted].”
Morris, 127 F.3d at 1055–56.
The noted limitation was added via amendment on November 22,
2017. While the term “epitaxial structure” does not appear in the
Specification, as originally filed, the Specification does describe that the
field termination region and the JFET region can each be made via an
epitaxial process. Spec. ¶ 39 (describing that “the JFET region 76 [in Figure
4E] may be provided via an epitaxial growth process that takes place before
providing the junction implants 60”), id., ¶ 40 (describing the formation of
the field termination region 62 in Figure 4H via an epitaxial process).
Therefore, each of the field termination region and the JFET region in the
claimed IGBT device may have an epitaxial structure resulting from the
respective epitaxial process used to form them.
We next consider the meaning of “different” epitaxial structures. The
Examiner’s broadest reasonable interpretation of the noted language is that
the claimed first and second epitaxial structures are different in the sense
that each is formed by different epitaxial processes during the formation of
the IGBT device. Ans. 8. In other words, each of the first and second
epitaxial structures is formed by a separate epitaxial process during the
formation of the IGBT device. This interpretation is consistent with the
noted disclosure in paragraphs 39–40 of the Specification.
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Appellant does not dispute adequately the Examiner’s interpretation
of the claim language in the Appeal and Reply Briefs. See generally Appeal
and Reply Br.’s. Therefore, we agree with the Examiner’s broadest
reasonable interpretation of the claim 1 language “the JFET region is
provided by a second epitaxial structure that is different from the first
epitaxial structure [of the field termination region]” as meaning that each
region is made by a separate epitaxial process during the formation of the
IGBT device.
REJECTIONS
After review of the respective positions the Appellant and the
Examiner present, we AFFIRM the Examiner’s rejection of claims 1–11, 13,
14, and 31–33 under 35 U.S.C. § 103 for the reasons the Examiner provides
in the Final Action and the Answer. We add the following for emphasis.
Claim 1 recites an insulated gate bipolar transistor (IGBT) device
comprising a field termination region provided by a first epitaxial structure
and a junction field effect transistor (JFET) region provided by a second
epitaxial structure that is different from the first epitaxial structure.
The Examiner determines that the combined teachings of Ryu, Zhang
and Yilmaz suggest an IGBT device satisfying all of the limitations of claim
1 and concludes that the combined teachings would have rendered the claim
obvious. Final Act. 3–4.
Appellant argues that the cited art does not teach a field termination
region provided by a first epitaxial structure and a JFET region provided by
a second epitaxial structure that is different than the first epitaxial structure
of the field termination region as claimed. Appeal Br. 5. According to
Appellant, there are physical differences between the claimed IGBT device
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and a conventional IGBT device having a field termination well provided via
an ion implantation process. Id. Specifically, Appellant argues that the way
the claimed IGBT is made avoids defects that may otherwise be caused if the
field termination region 62 is made via an ion implantation process. Id.
Appellant asserts that the claimed IGBT device maintains the integrity of the
IGBT stack and increases the performance of the IGBT device. Id.
Appellant’s arguments are not persuasive of reversible error because
the arguments do not address the rejection the Examiner presents. It is well
established that the obviousness inquiry does not ask “whether the
references could be physically combined but whether the claimed inventions
are rendered obvious by the teachings of the prior art as a whole.” In re
Etter, 756 F.2d 852, 859 (Fed. Cir. 1985) (en banc); see also In re Keller,
642 F.2d 413, 425 (CCPA 1981) (stating “[t]he test for obviousness is not
whether the features of a secondary reference may be bodily incorporated
into the structure of the primary reference”). “[T]he test [for obviousness] is
what the combined teachings of the references would have suggested to
those of ordinary skill in the art.” Keller, 642 F.2d at 425–26.
The Examiner’s rejection is based on the combined teachings of Ryu,
Zhang, and Yilmaz. Final Act. 3–4. As the Examiner explains in the
Answer, Zhang teaches that it is conventional to make a JFET region of an
IGBT device via an epitaxial process. Ans. 8; Zhang ¶¶ 47–50. The
Examiner also notes that Yilmaz teaches epitaxially growing the drift region
64 in which the field termination region 40 is ultimately formed. Ans. 8;
Yilmaz col. 5, ll. 5–9, 15–17. While Yilmaz discloses forming the field
termination region preferably by ion implantation (Yilmaz col. 8, ll. 44–47),
the teachings of the cited prior art as a whole suggest that it is well known to
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deposit layers for an IGBT device through an epitaxial process. See Ryu ¶
46; Zhang ¶¶ 9, 33, 35, 36; Yilmaz col. 1, ll. 33–50, col. 5, ll. 1–7, col. 8, ll.
24–38. In fact, Zhang recognizes that epitaxial processes and ion
implantation processes are known to form layers of an IGBT device. Zhang
¶ 35 (discussing formation of a JFET region using either an epitaxial process
or an ion implantation process). Thus, Appellant has not adequately
explained why one skilled in the art, using no more than ordinary creativity,
would not have been capable of making an IGBT device comprising a field
termination region and a JFET region made by separate epitaxial processes.
See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 421 (2007) (“A person of
ordinary skill is also a person of ordinary creativity, not an automaton.”); see
also In re Sovish, 769 F.2d 738, 743 (Fed. Cir. 1985) (presuming skill on the
part of one of ordinary skill in the art).
Moreover, given that the prior art recognizes that layers for an IGBT
device can be formed by epitaxial processes, there is a reasonable basis for
one skilled in the art to reasonably expect that the IGBT device from the
combined teachings of the prior art having the field termination region and
JFET region with epitaxial structures would possess the characteristics of the
claimed invention. Appellant has not explained adequately how the claimed
IGBT device differs structurally from the IGBT device resulting from the
combined teachings of the applied prior art. See In re Spada, 911 F.2d 705,
708 (Fed. Cir. 1990) and In re Best, 562 F.2d 1252, 1254–56 (CCPA 1977)
(explaining that when the Examiner establishes a reasonable basis for
concluding that the claimed and prior art products appear to be the same, the
burden is properly shifted to the applicant to show that they are not). In
addition, Appellant has not directed us to any objective evidence that
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supports adequately the assertion that there are physical differences between
the claimed IGBT device and the IGBT device from the combined teachings
of the cited art. Appellant’s attorney arguments cannot take the place of
evidence. See In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir. 1984); In re
Payne, 606 F.2d 303, 315 (CCPA 1979).
Accordingly, we affirm the Examiner’s prior art rejections of claims
1–11, 13, 14, and 31–33 under 35 U.S.C. § 103 for the reasons the Examiner
presents and we give above.
CONCLUSION
In summary:

Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1–4, 7–11,
13, 14,
31–33
103 Ryu, Zhang,
Yilmaz
1–4, 7–11,
13, 14,
31–33

5, 6 103 Ryu, Zhang,
Yilmaz, Merrill
5, 6
Overall
Outcome
1–11, 13,
14, 31–33

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)(iv).

AFFIRMED