Ex Parte Hirler et al

Patent Trial and Appeal Board

Jul 24, 2018

13197903 (P.T.A.B. Jul. 24, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
13/197,903 08/04/2011 Franz Hider
57579 7590 07/26/2018
MURPHY, BILAK & HOMILLER/INFINEON TECHNOLOGIES
1255 Crescent Green
Suite 200
CARY, NC 27518
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
ATTORNEY DOCKET NO. CONFIRMATION NO.
1012-0219 / 2010P50477 6736
us
EXAMINER
WEBB, VERNONP
ART UNIT PAPER NUMBER
2811
NOTIFICATION DATE DELIVERY MODE
07/26/2018 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):
official@mbhiplaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte FRANZ HIRLER, ANTON MADDER, THOMAS
RAKER, HANS-JOACHIM SCHULZE, and
WOLFGANG WERNER
Appeal2017-008147
Application 13/197 ,903
Technology Center 2800
Before TERRY J. OWENS, DEBRA L. DENNETT, and
MICHAEL G. McMANUS, Administrative Patent Judges.
OWENS, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
The Appellants appeal under 35 U.S.C. § 134(a) from the Examiner's
rejection of claims 1-10 and 12-21. We have jurisdiction under
35 U.S.C. § 6(b).
The Invention
The Appellants claim a transistor component. Claims 1 and 10 are
illustrative:
1. A transistor component, comprising:
in a semiconductor body a source zone and a drift zone of
a first conduction type;
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Application 13/197 ,903
a body zone of a second conduction type complementary
to the first conduction type, the body zone being arranged
between the drift zone and the source zone;
a source electrode in contact with the source zone and the
body zone;
a gate electrode adjacent the body zone and dielectrically
insulated from the body zone by a gate dielectric layer;
a diode structure connected between the drift zone and
the source electrode and which comprises:
a first emitter zone adjoining the drift zone in the
semiconductor body; and
a second emitter zone of the first conduction type
adjoining the first emitter zone,
the second emitter zone being connected to the
source electrode and having an emitter efficiency y of
less than 0.7.
10. A transistor component, comprising:
in a semiconductor body a source zone and a drift zone of
a first conduction type;
a body zone of a second conduction type complementary
to the first conduction type, the body zone being arranged
between the drift zone and the source zone;
a source electrode in contact with the source zone and the
body zone;
a gate electrode adjacent the body zone and dielectrically
insulated from the body zone by a gate dielectric layer; and
a Schottky diode structure connected between the drift
zone and the source electrode, the Schottky diode structure
comprising a first emitter zone of the second conduction type
adjoining the drift zone and extending to a surface of the
semiconductor body at which the source electrode is disposed.
Derraa
Ruething
Zundel
The References
US 7,091,513 Bl
US 2007/0120181 Al
US 2009/0039419 Al
2
Aug. 15, 2006
May 31, 2007
Feb. 12,2009
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Application 13/197 ,903
The Rejections
The claims stand rejected under 35 U.S.C. § 103 as follows: claims 1,
2, 7-10 and 12-21 over Zundel in view ofRuething 1 and claims 3---6 over
Zundel in view of Ruething and Derraa.
OPINION
We reverse the rejections. We need address only the independent
claims (1 and 10).
Claim 1
Claim 1 requires a semiconductor body comprising a diode structure
which is connected between a drift zone and a source electrode and has 1) a
first emitter zone adjoining the drift zone, and 2) a second emitter zone
which adjoins the first emitter zone, is connected to the source electrode, and
has an emitter efficiency less than O. 7.
Zundel discloses a semiconductor body (100) comprising a structure
( which the Examiner relies upon as corresponding to the Appellants' diode
structure (Final Act. 4)) having 1) a portion between a drift zone (12)'s
safety zone (121) and a source electrode (15), 2) a drift zone (12)'s mesa
region (122) (which the Examiner relies upon as corresponding to the
Appellants' first emitter zone (Final Act. 4)) adjoining the safety zone (121 ),
and 3) a drain zone (11)/semiconductor layer (16) (which the Examiner
relies upon as corresponding to the Appellants' second emitter zone (Final
Act. 4)) (,r,r 20, 44; Figs. 1, 3).
1 The Examiner's statement of the rejection excludes rejected claim 21 and
includes canceled claim 11 (Final Act. 3, 9).
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Application 13/197 ,903
Ruething discloses a semiconductor body (100) wherein, to reduce
latch-up,2 an emitter zone (11) has a lower emitter efficiency in a region
corresponding to a second cell array section (102) than in a region
corresponding to a first cell array section (i1i1 3, 10, 25; Fig. 1 ). The second
cell array section (102)'s "zone having a reduced emitter efficiency
preferably reaches, in the lateral direction, into the first cell array section.
The extent of this zone having a reduced emitter efficiency into the first cell
array section is preferably 0.1 to 2 diffusion lengths of free charge carriers"
(i129).
The Examiner finds that Zundel' s safety zone ( 121) is a drift zone
(Final Act. 4 ).
Zundel' s drift zone is item 12 and comprises a safety zone (121) and a
mesa zone (122) (i-f 32; Fig. 1). Thus, the Examiner's finding that Zundel
discloses "a first emitter zone (item 122) adjoining the drift zone (item 121 )"
(Final Act. 4) is not supported by Zundel.
The Examiner finds that "the term 'adjoin' may include indirect or
directly 'touching at some point or along a line"' (Ans. 4) and that Zundel
discloses "a second emitter zone (item 11/16) of the first conduction type
adjoining the first emitter zone (item 122)" (Final Act. 4).
"'[D]uring examination proceedings, claims are given their broadest
reasonable interpretation consistent with the specification."' In re
Translogic Tech. Inc., 504 F.3d 1249, 1256 (Fed. Cir. 2007) (quoting In re
Hyatt, 211 F.3d 1367, 1372 (Fed. Cir. 2000)). The ordinary meaning of
2 "Latch-up is an operation in which a parasitic npn bipolar transistor which
is formed from then-doped source zone 15, the p-doped body zone 14 and
then-doped drift zone 12 switches on" (i-f 6).
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Application 13/197 ,903
"adjoining" is "touching or bounding at a point or line."3 According to that
meaning, Zundel's drain zone (11) adjoins the drift zone (12) but does not
adjoin the drift zone (12)'s mesa zone (122) which is separated from the
drain zone (11) by the drift zone (12)'s safety zone (121) (Fig. 1). Zundel's
semiconductor layer (16) does not adjoin the drift zone (12)'s mesa
zone (122) but, rather, is separated therefrom by the drain zone (11) and the
drift zone (12 )' s safety zone (121) (Fig. 3 ). The Examiner does not establish
that the Appellants' Specification broadens the meaning of the term
"adjoining" to include items separated from one another by something else.
The Examiner finds that the Appellants' claim term "connected"
includes "electrically connected" and that Zundel' s drain zone ( 11) and
semiconductor layer (16) are electrically connected to the source
electrode (15) (Final Act. 4; Ans. 4).
The Appellants' Specification states that the diode structure's
electrode ( 41) and the source electrode (21) are "contact-connected"
(Spec. ,r 69). The Examiner does not address that disclosure and establish
that the broadest meaning of the claim term "connected" consistent
therewith includes "electrically connected." Also, when claims are
interpreted, all limitations must be given effect. See In re Angstadt, 537
F.2d 498, 501 (CCPA 1976) ("we must give effect to all claim limitations").
The Examiner does not establish that the Examiner's interpretation of the
Appellants' claim term "connected" as including electrical connection
resulting from all components being directly or indirectly electrically
3 Merriam-Webster's Collegiate Dictionary 16 (1 ith ed. 2003).
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Application 13/197 ,903
connected does not render the Appellants' claim term "connected"
superfluous.
The Examiner finds that "on the surface, the claim limitation of 'the
second emitter zone being connected to the source electrode and having an
emitter efficiency y of less than O. 7' does not specify what the emitter
efficiency is in respect to" (Ans. 3).
That finding, which apparently pertains to the breadth of the claim
term "emitter efficiency," improperly does not address the Appellants'
Specification's definition of emitter efficiency as y = 1 -}3i/(h1 + }32), where
}31 is a first charge carrier current flowing from the first emitter zone (31)
into the second emitter zone (32) when the forward voltage of the diode
structure is reached, and }32 is a second charge carrier current flowing from
the second emitter zone (32) into the first emitter zone (31) when the
forward voltage of the diode structure is reached (Spec. ,r 39), and disclosure
that "the properties of the first and of the second emitter zones 31, 32 are
chosen such that the emitter efficiency y of the second emitter zone 32 is less
than 0.7" (Spec. ,r 37).
The Examiner finds that "Ruething et al. disclose an emitter zone
having an emitter efficiency y of less than 0.7, more specifically 'The extent
of this zone having a reduced emitter efficiency into the first cell array
section is preferably 0.1 to 2 diffusion lengths of free charge carriers.' (i.e.,
0.7 is in the disclosed range, pgs. 2-3, paragraph [0029])" (Ans. 2).
The numerical range in that portion of Ruething is diffusion lengths of
free charge carriers, not emitter efficiency.
The Examiner concludes that "[a]pplying Ruething's teaching of
reducing the emitter efficiency to the device disclosed by Zundel et al. such
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that the second emitter zone having [ sic, has] an emitter efficiency y of less
than 0. 7 would have been obvious for one of ordinary skill in the art and
would have resulted in successfully providing a power IGBT devices [sic]
which is provides [sic] improved latch up behavior within the device"
(Ans. 3).
The Examiner does not compare Zundel's and Ruething's devices and
establish, based on that comparison, that Ruething's disclosure regarding
reducing latch up would have led one of ordinary skill in the art to apply
Ruething' s disclosure regarding emitter efficiency to Zundel' s device such
that a second cell array section zone has an emitter efficiency less than 0.7 as
that term is defined in the Appellants' Specification.
Claim 10
Claim 10 requires a semiconductor body comprising a Schottky diode
structure connected between a drift zone and a source electrode and having a
first emitter zone which adjoins the drift zone and extends to a surface of the
semiconductor body at which the source electrode is disposed.
The Examiner finds that Zundel discloses a Schottky diode structure
connected between the drift zone ( 12)' s safety zone ( 121) and the source
electrode (15) and "comprising a first emitter zone (item 11/16) of the
second conduction type adjoining the drift zone (item 121) and extending to
a surface of the semiconductor body; at which the source electrode (item 15)
is disposed" (Final Act. 7).
The region between Zundel's safety zone (121) and source
electrode (15) does not comprise the drain zone (11) and semiconductor
layer (16) and includes, but is not connected between, the drift zone (13) and
the source electrode (15) (Fig. 3).
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Thus, the Examiner has not set forth a factual basis that is sufficient to
support a conclusion of obviousness of the Appellants' claimed transistor
components. See In re Warner, 379 F .2d 1011, 1017 (CCP A 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"). Accordingly, we reverse the rejections.
DECISION
The rejections under 35 U.S.C. § 103 of claims 1, 2, 7-10, and 12-21
over Zundel in view of Ruething and claims 3---6 over Zundel in view of
Ruething and Derraa are reversed.
The Examiner's decision is reversed.
REVERSED
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