Ex Parte Yang et al

Patent Trial and Appeal Board

Oct 30, 2018

15157607 (P.T.A.B. Oct. 30, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
15/157,607
16708 7590
Bing K Yen
P.O.Box 1538
Cupertino, CA 95015
05/18/2016
11/01/2018
FIRST NAMED INVENTOR
Hongxin Yang
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.
AVALANCHE-0173US 6744
EXAMINER
AHMAD, KHAJA
ART UNIT PAPER NUMBER
2813
NOTIFICATION DATE DELIVERY MODE
11/01/2018 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):
bing.k. yen@gmail.com
bing@ avalanche-technology. com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte HONGXIN YANG, KIMIHIRO SATOH, and
XIAOBINWANG
Appeal2018-004714
Application 15/157,607
Technology Center 2800
Before JAMES C. HOUSEL, N. WHITNEY WILSON, and
JEFFREY R. SNAY, Administrative Patent Judges.
WILSON, Administrative Patent Judge.
DECISION ON APPEAL
Appellant appeals under 35 U.S.C. § 134(a) from the Examiner's May
8, 2017 decision finally rejecting claims 1-20. 1 We have jurisdiction over
the appeal under 35 U.S.C. § 6(b ).
We reverse.
1 Appellant is the Applicant, Avalanche Technology Incorporated, which is
also identified as the real party in interest (Appeal Br. 2).
Appeal2018-004714
Application 15/157 ,607
CLAIMED SUBJECT MATTER
Appellant's disclosure is directed to a memory device which includes
an array of memory cells (Abstract). Each memory cell includes a memory
element connected to a two-terminal selector element (id.). The two-
terminal selector element includes a first electrode and a second electrode
with a switching layer in between (id.). The switching layer includes a
plurality of metal-rich clusters embedded in a matrix (id.). Independent
claims 1 and 20 are representative and are reproduced below from the
Claims Appendix of the Appeal Brief:
1. A memory device comprising an array of memory cells,
each of said memory cells including a memory element
connected to a two-terminal selector element, said two-terminal
selector element comprising a first electrode and a second
electrode with a switching layer interposed therebetween, said
switching layer including a plurality of metal-rich clusters
embedded in a matrix, wherein said switching layer has single
resistance state in absence of an applied voltage thereto.
20. A memory device comprising an array of memory cells,
each of said memory cells including a memory element
connected to a two-terminal selector element, said two-terminal
selector element comprising a first electrode and a second
electrode with a switching layer interposed therebetween, said
switching layer including a plurality of metal-rich clusters
embedded in a matrix, wherein each of said first and second
electrodes is made of a material selected from the group
consisting of iridium, ruthenium, and any combinations thereof.
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Appeal2018-004714
Application 15/157 ,607
REJECTIONS
I. Claims 1-19 are rejected under 35 U.S.C. § I03(a) as
unpatentable over Kuo 2 in view of Zhang. 3
II. Claim 20 is rejected under 35 U.S.C. § I03(a) as unpatentable
over Kuo in view of Zhang and Baek. 4
DISCUSSION
The Examiner finds-and Appellant does not dispute-that Kuo
discloses each of the elements of claim 1, except that Kuo does not teach
that its switching layer S includes a plurality of metal-rich clusters
embedded in a matrix (Final Act. 3, citing Kuo, FIGS. 1-7, ,r,r 16, 27).
The Examiner finds that Zhang is "pertinent art," and discloses a
resistive switching nonvolatile random access memory (ReRAM) formed
using memory elements with two or more stable states with different
resistances and having a metal insulator metal (MIM) structure (Final Act.
3). The Examiner further finds that Zhang discloses that its resistive
memory devices can include metal nanoparticles in a matrix in a switching
layer disposed between two electrodes in order to produce a structure with
low power consumption and low switching current (Final Act. 3, citing
Zhang, FIG. 10, ,r,r 8, 10). The Examiner also finds that Zhang's MIM
structure "is an equivalent structure of the switching layer of Kuo because ..
. their functionality is equivalent which is switching between ON (low
resistance) and OFF (high resistance)" (Final Act. 3--4 ). The Examiner
2 Kuo et al., US 2014/0209892 Al, published July 31, 2014.
3 Zhang et al., US 2014/0264224 Al, published September 18, 2014.
4 Baek et al., US 2007/0159869 Al, published July 12, 2007.
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Appeal2018-004714
Application 15/157 ,607
concludes that it would have been obvious to include metal rich clusters
embedded in a matrix in Kuo' s device in order to have low power
consumption and low switching current (Final Act. 4).
Appellant argues, inter alia, that a person of skill in the art would not
have substituted Zhang' s switching layer for Kuo' s switching layer.
Appellant contends that Kuo's switching layer is a volatile structure (i.e. it is
insulative in the absence of an applied voltage but conductive when an
appropriate voltage is applied), so that it reverts to the insulative state when
the voltage is removed, which prevents current leakage through the selector
element when not being selected for read or write operation (Appeal Br. 7).
By contrast, according to Appellant, Zhang' s switching layer is designed for
a non-volatile memory, which means that it maintains its resistance level
even after removal of the applied voltage (id.). Therefore, Appellant argues,
a person of skill in the art would not have substituted Zhang' s switching
layer into Kuo' s device because doing so would result in the selector
element remaining conductive after removal of the applied voltage, which
would cause current leakage (Appeal Br. 7-8).
In response, the Examiner finds that the materials of Zhang' s insulator
and the materials of Kuo are not the same and:
Therefore, by including a plurality of metal-rich clusters in a
matrix in the insulator ([0027]) of Kuo will not make the
selector element (S, Figure 1 of Kuo) a nonvolatile element due
to the difference between the materials of the insulator between
the two electrodes, instead, by adding such metal-rich clusters
in the insulator of Kuo will reduce the resistivity such that the
turning ON current will be less for the selector element of Kuo,
and hence the modification will provide a lower power
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Appeal2018-004714
Application 15/157 ,607
consumption in the device of Kuo according to the teaching of
Zhang ([001 OJ).
(Ans. 5).
However, as argued by Appellant (Reply Br. 5), Zhang teaches that its
metal rich clusters act as permanent anchors for stabilizing conductive
filaments which serve to reduce the tum-on current (Zhang, FIGS. 3A-3A).
This can be seen because metal nanoparticles 322 and 323 do not move even
as the conductive filaments are set and reset in FIGS. 3A, 3B, and 3C. Thus,
the benefit of Zhang' s system cited by the Examiner to provide the
necessary motivation to incorporate Zhang's metal particles into Kuo's
system (low power consumption and low switching current) results from the
Zhang's switching layer being non-volatile. Modifying that switching layer
to make it volatile so that it would work with Kuo' s system would eliminate
the advantage cited by the Examiner as motivatation for the modification.
Accordingly, we conclude that Appellant has shown reversible error
in the rejection of claim 1 over Kuo and Zhang, and we, therefore, reverse
that rejection. The rejection of claim 20 over Kuo, Zhang, and Baek is
reversed for the same reasons.
CONCLUSION
We REVERSE the rejection of claims 1-19 under 35 U.S.C. § 103(a)
as unpatentable over Kuo in view of Zhang.
We REVERSE the rejection of claim 20 under 35 U.S.C. § 103(a) as
unpatentable over Kuo in view of Zhang and Baek.
REVERSED
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