Ex Parte YAMAZAKI et al

Patent Trials and Appeals Board

May 15, 2019

14187830 - (D) (P.T.A.B. May. 15, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
14/187,830 02/24/2014
31780 7590 05/17/2019
Robinson Intellectual Property Law Office, P.C.
3975 Fair Ridge Drive
Suite 20 North
Fairfax, VA 22033
FIRST NAMED INVENTOR
Shunpei YAMAZAKI
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.
0756-10379 2115
EXAMINER
MAI,ANHD
ART UNIT PAPER NUMBER
2829
NOTIFICATION DATE DELIVERY MODE
05/17/2019 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):
ptomail@riplo.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte SHUNPEI YAMAZAKI, JUN KOY AMA,
and KEIT ARO IMAI
Appeal2017-007360
Application 14/187,830 1
Technology Center 2800
Before ROBERT E. NAPPI, ERIC S. FRAHM, and MICHAEL T. CYGAN,
Administrative Patent Judges.
CYGAN, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF CASE
Introduction
Appellants appeal under 35 U.S.C. § 134(a) from the Examiner's
Final Rejection of claims 2-25. We have jurisdiction under 35 U.S.C.
§ 6(b).
We affirm-in-part.
1 According to Appellants, the real party in interest is Semiconductor Energy
Laboratory Co., Ltd. App. Br. 3.
Appeal2017-007360
Application 14/187,830
Disclosed Subject Matter and Exemplary Claim
The disclosed subject matter relates to semiconductor devices; in
particular, to providing a device structure that prevents damage from high
flow-through current and reduces leakage current. Spec. ,r,r 8-9. For that
purpose, the disclosed subject matter employs, for example, a stack of a
transistor using an oxide semiconductor and a transistor using a material
other than an oxide semiconductor.
Independent claim 2 is exemplary of the disclosed invention, and
reads as follows:
2. A semiconductor device comprising an inverter
circuit, the inverter circuit comprising:
a p-type transistor comprising a single crystal
semiconductor material, wherein a channel formation region of
the p-type transistor is formed with the single crystal
semiconductor material;
an insulating layer over the p-type transistor; and
an n-type transistor over the insulating layer, then-type
transistor comprising a channel formation region, wherein the
channel formation region of the n-type transistor comprises an
oxide semiconductor material including indium,
wherein one of a source and a drain of the p-type
transistor is electrically connected to one of a source and a drain
of the n-type transistor, and
wherein a gate of the n-type transistor is electrically
connected to a gate of the p-type transistor.
Independent claims 8, 14, and 22 recite limitations of similar
scope as the limitations recited in claim 2. Dependent claims 3-7, 9-
14, and 15-21 each incorporate the limitations of the independent
claims from which they depend.
2
Appeal2017-007360
Application 14/187,830
Examiner's Rejection
The Examiner rejects claims 2--4, 6-10, 12-18, 20, and 21 under
35 U.S.C. § 103(a) as being obvious over the combination of Gonzalez (US
2005/0026339 Al, published Feb. 3, 2005) and Iwasaki (US 2009/0045397
Al, published Feb. 19, 2009). Final Act. 2.
The Examiner rejects claims 5, 11, 19, and 22-25 under 35 U.S.C.
§ 103 (a) as being obvious over the combination of Gonzalez and Iwasaki,
further in view of Yamazaki et al. (US 2009/0078939 Al, published March
26, 2009) (hereinafter "Yamazaki"). Final Act. 7.
ANALYSIS
We have reviewed the Examiner's rejection (Final Act. 2-25) in light
of Appellants' contentions that the Examiner has erred (App. Br. 13-22;
Reply Br. 1-9). Further, we have reviewed the Examiner's response to
Appellants' contentions (Ans. 2-10). We are persuaded by Appellants'
arguments of error in the Examiner's rejections of claims 6, 12, 14--21, and
25. We are not persuaded by Appellants' arguments of error in the
Examiner's rejections of claims 2-5, 7-11, 13, and 22.
Claims 2-5, 7-11, 13, and 22-24
With respect to the rejection of claims 2--4, 7-10, and 13 under 35
U.S.C. § I03(a), the issue raised by Appellants is whether one of ordinary
skill in the art would have combined the relied-upon teachings or
suggestions of Gonzalez with the relied-upon teachings or suggestions of
Iwasaki to make obvious the claimed invention. App. Br. 14--20. The
Examiner's rationale for that combination is that one of ordinary skill in the
art would have combined the teachings or suggestions of Gonzalez and
Iwasaki in such a manner as to replace Gonzalez's n-type transistor with
3
Appeal2017-007360
Application 14/187,830
Iwasaki's n-type transistor, in such a manner as to create the claimed circuit
having Iwasaki's n-type transistor over the lower p-type transistor of
Gonzalez, because Iwasaki's n-type transistor has "superior properties"
without subjecting the lower device to a high temperature process. Final
Act. 4, 12; App. Br. 14.
Appellants first contend that if Iwasaki' s transistor was superior, one
of ordinary skill in the art would have been motivated to substitute Iwasaki's
transistors for all of Gonzalez's transistors, not just the upper transistor as set
forth in the rejection. App. Br. 15. However, as noted by the Examiner, the
potential for other advantageous combinations does not detract from a
finding of obviousness where the differences between the claimed invention
and the prior art would otherwise be obvious. Ans. 14; see, e.g., Ex parte
Obiaya, 227 USPQ 58, 60 (BP AI 1985). Accordingly, we do not find this
contention persuasive as to error in the combination of references as set forth
in the rejection.
Appellants next contend that Gonzalez itself teaches formation of the
upper transistor at a lowered temperature, rendering superfluous the
Examiner's stated motivation for replacing that transistor with Iwasaki's
transistor. App. Br. 15-16. However, as noted by the Examiner, Gonzalez's
method of bonding requires high temperature to form effectively the
polycrystalline n-type transistor onto the lower transistor. Ans. 15. While
Gonzalez teaches that bonding temperatures of 700° C may be used to bond
polycrystalline silicon conductive material 38 to base 502, these
temperatures "will probably not effectively bond insulative material 3 6 to
base 502." Gonzalez ,r 33 ( emphasis omitted). Since, as shown in Figures
4--8, these bonds secure the upper transistor to the lower transistor, Gonzalez
4
Appeal2017-007360
Application 14/187,830
admits the lower temperature processing to have a drawback associated with
it. Furthermore, Gonzalez states that bonding at high temperature causes
unwanted diffusion of dopants. Gonzalez ,r 32. Accordingly, Appellants are
not persuasive in showing error in the Examiner's motivation of providing
formation of an upper layer without unwanted diffusion in the lower layer
through the use of Iwasaki's lower-temperature method.
Appellants further argue that the transistor of Iwasaki would have
"inferior characteristics" to that of Gonzalez. App. Br. 16-18. However, it
is not necessary that the combination of reference achieve all of the same
advantages and features of each individual reference. See, e.g., Cross Med.
Prods., Inc. v. Medtronic Sofamor Danek, Inc., 424 F.3d 1293, 1323, (Fed.
Cir. 2005) ("One of ordinary skill in the art need not see the identical
problem addressed in a prior art reference to be motivated to apply its
teachings"); In re Keller, 642 F.2d 413,425 (CCPA 1981) (explaining that
the test for obviousness is "not whether the features of a secondary reference
may be bodily incorporated into the structure of the primary reference," but
instead "what the combined teachings of the references would have
suggested to those of ordinary skill in the art"). Furthermore, we agree with
the Examiner that these characteristics, such as field-effect mobility, are not
reflected in the limitations of the claims. Ans. 5. Accordingly, we are not
persuaded of error in the Examiner's determination that the relied-upon
teachings of the Gonzalez and Iwasaki would have suggested Appellants'
claimed invention to one having ordinary skill in the art.
For the above-mentioned reasons, we sustain the Examiner's rejection
of claim 2. Appellants do not present separate patentability arguments for
any of claims 3--4, 7-10, and 13, other than those raised for independent
5
Appeal2017-007360
Application 14/187,830
claim 2. Therefore, we sustain the Examiner's obviousness rejection of
claims. See 37 C.F.R. §4I.37(c)(l)(iv). Appellants rely on the same alleged
deficiency of Iwasaki in arguing against the rejections of claims 5, 11, and
22-24, which were rejected over the combination of Gonzalez and Iwasaki
in view of Yamazaki. App. Br. 10. We decide the outcome of claims 5, 11,
and 22-24 on the same basis as claims 2, and 8, from which claims 5 and 8
depend, and for which the limitations at issue are commensurate in scope
with those in claims 22-24. Therefore, Appellants have not shown that the
Examiner erred in rejecting claims 5, 11, and 22-24. See 37 C.F.R.
§4I.37(c)(l)(iv). Accordingly, we sustain the Examiner's obviousness
rejection of claims 2-5, 7-11, 13, and 22-24.
Claims 6, 12, 20, and 25
With respect to the rejection of claims 6, 12, and 20 under 35 U.S.C.
§ 103(a), the issue raised by Appellants is whether Iwasaki teaches or
suggests "an oxide semiconductor material having a degree of crystallization
of 90% or more."
The Examiner finds Iwasaki to teach an amorphous oxide
semiconductor material that is, in the Examiner's words, "100% amorphous
crystal." Final Act. 13-14. The Examiner also points to a teaching or
suggestion in Iwasaki that the material "may contain a fine crystalline."
Ans. 5. Appellants argue that amorphous is defined as "[n]ot made of
crystals," "lacking distinct crystalline structure," and "not having a
crystalline form." App. Br. 11-12 (citing various dictionaries) (emphasis
omitted). Appellants also point to portions of Iwasaki that distinguish
"amorphous" oxide films from "crystallized" oxide films. Id. at 12 ( citing
Spec. ,r,r 11, 66, and 67).
6
Appeal2017-007360
Application 14/187,830
We find persuasive Appellants' contention, supported by dictionary
definitions of "amorphous," that a teaching or suggestion of an amorphous
oxide semiconductor material is one that does not have a defined crystalline
form. The Examiner has not pointed to any authority contradicting the
dictionary definitions of "amorphous" that exclude a crystalline form.
Further, the Examiner's reliance on Iwasaki's statement that the material
"may contain a fine crystalline" does not support a finding that Iwasaki
teaches or suggests the claimed "crystallization of 90% or more."
We are persuaded by Appellants' contention of error in the rejections
of claims 6, 12, and 20, and reverse those rejections. As to the rejection of
claim 25 as being obvious over the combination of Gonzalez, Iwasaki, and
Yamazaki, the Examiner has not found, nor do we determine, that Yamazaki
teaches or suggests the claimed "crystallization of 90% or more." We
therefore reverse the Examiner's rejection of claim 25. Accordingly, we
reverse the Examiner's rejection of claims 6, 12, 20, and 25.
Claims 14--21
With respect to the rejection of claims 14--18 and 20-21 under
35 U.S.C. § 103(a), the issue raised by Appellants is whether the
combination of the Gonzalez and Iwasaki references teach the claimed off-
state current of lx10-13 A or less. The Examiner finds this value of current
to be inherent in the Iwasaki reference. The Examiner finds Iwasaki to
disclose the same oxide semiconductor material including indium, having
the same range of hydrogen concentration as in the claimed invention. Ans.
5. The Examiner determines that the off-state current derives solely from
the type of material and the hydrogen concentration. Ans. 5---6. The
Examiner determines that the Iwasaki reference therefore inherently
7
Appeal2017-007360
Application 14/187,830
possesses the same properties as the claimed invention, including the same
off-state current of lxl0-13 A or less. Id; Final Act. 6. As stated by the
Examiner, "[ s Jame materials, same characteristics." Final Act. 6.
Appellants contend that such a value is not inherent, because, inter
alia, Iwasaki states "the leak current between the source and drain electrodes
and that between the drain and gate electrodes can be decreased to
approximately 10-7 A," i.e., higher than the claimed threshold. App. Br. 14
(citing Iwasaki ,r 78). Appellants further contend that Iwasaki's teaching or
suggestion of "oxide semiconductor material including indium" is a broad
genus for which the Examiner has not established the same off-state current
values extend to all members of that genus. Id. at 13. Appellants cite, as
support for this proposition, Iwasaki's recognition that electrical properties
of the semiconductor material may be impacted by the concentration of
added hydrogen and other manufacturing variables. Id. at 14. Appellants
state, "the fact that a certain result or characteristic may occur or be present
in the prior art is not sufficient to establish the inherency of that result or
characteristic." Reply Br. 4 ( citing In re Rijckaert, 9 F .3d 1531, 1534 (Fed.
Cir. 1993) and In re Robinson, 169 F.3d 743, 745 (Fed. Cir. 1999)).
The Examiner states that the leak current is not the same as the
claimed off-state current. Final Act. 13. The Examiner explains that "off-
state current" relates to "threshold voltage or dopant concentration within
the channel." Id. The Examiner finds Iwasaki to have a similar carrier
concentration of hydrogen (5xl019 atoms/cm3 or less) as Appellants'
invention. The Examiner determines that this hydrogen concentration is the
factor responsible for the off-state current. Id.; Ans. 5-6 ( citing Spec. ,r 3 6).
8
Appeal2017-007360
Application 14/187,830
We find persuasive Appellants' contentions that the Examiner has not
shown an inherent off-state current of lxl0-13 A or less. The Examiner's
citation to the Specification shows that off-state current is related to
hydrogen concentration. Ans. 5---6 (citing Spec. ,r 36). However, the
Examiner has not shown that other variables present in either Appellants' or
Iwasaki' s oxide semiconductors could result in different off-state currents
despite both having the same or similar hydrogen concentrations. For
example, Appellants cite to paragraph 57 of Iwasaki, which explains that
although electron carrier concentration may be altered by changing the
hydrogen concentration, it is also "dependent on the oxygen partial pressure
during film formation and the material composition." App. Br. 14; Iwasaki
,r 57.
Accordingly, we find persuasive Appellants' contentions that the
Examiner has not shown Iwasaki to inherently teach the claimed off-state
current range. We therefore reverse the Examiner's rejection of claims 14--
18 and 20-21.
As to the rejection of claim 19 as being obvious over the combination
of Gonzalez, Iwasaki, and Yamazaki, the Examiner has not found, nor do we
determine, that Yamazaki teaches or suggests the claimed off-state current
range. We therefore reverse the Examiner's rejection of claim 19.
DECISION
We AFFIRM the Examiner's rejections of claims 2-5, 7-11, 13, and
22-24 under 35 U.S.C. § 103(a). We REVERSE the Examiner's rejections
of claims 6, 12, 14--21, and 25.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(l )(iv).
9
Appeal2017-007360
Application 14/187,830
AFFIRMED-IN-PART
10