Ex Parte LIU et al

Patent Trials and Appeals Board

Apr 22, 2019

14861886 - (D) (P.T.A.B. Apr. 22, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
14/861,886 09/22/2015
23125 7590 04/24/2019
NXP USA, Inc.
LAW DEPARTMENT
6501 William Cannon Drive West TX30/0E62
AUSTIN, TX 78735
FIRST NAMED INVENTOR
LIANJUNLIU
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.
SA25388ZR 1971
EXAMINER
BRADLEY, STEPHEN M
ART UNIT PAPER NUMBER
2819
NOTIFICATION DATE DELIVERY MODE
04/24/2019 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):
ip.department.us@nxp.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE
THE PA TENT TRIAL AND APPEAL BOARD
Ex parte LIANJUN LIU1
and David J. Monk
Appeal 2018-004368
Application 14/861,886
Technology Center 2800
Before MARK NAGUMO, MONTE T. SQUIRE, and
MICHAEL G. McMANUS, Administrative Patent Judges.
NAGUMO, Administrative Patent Judge.
DECISION ON APPEAL
Lianjun Liu and David J. Monk ("Liu") timely appeal
under 35 U.S.C. § 134(a) from the Final Rejection2 of all pending claims 1-
15. We have jurisdiction. 35 U.S.C. § 6. We reverse for reasons well-stated
by Liu.
1 The real party in interest is identified as NXP, USA, Inc. (Appeal Brief,
filed 25 September 2017 ("Br."), 3.)
2 Office Action mailed 24 May 2017 ("Final Rejection"; cited as "FR").
Appeal 2018-004368
Application 14/861,886
A. Introduction3
OPINION
The subject matter on appeal relates to processes of making different
types of sensors on the same semiconductor device. (Spec. 1 [0001].)
According to the '886 Specification, "[ fJorming a sensor having multiple
stimulus sensing capability in a miniaturized package has been sought for
use in a number of applications." (Id. at 3 [0012].) Two prominent classes
of sensors are microelectromechanical systems ("MEMS") sensors, such as
pressure sensors, accelerometers, etc. (id. at 1 [0002]), and magnetic field
sensors ("magnetometers") that are capable of sensing magnetic fields along
one or more mutually exclusive axes (id. at 1 [0003]). While it would be
desirable to have a semiconductor-based device having both MEMS and
magnetic sensors on the same chip (id. at 2 [0005]), in the words of the
Specification, "[ m Jagnetic sensors and MEMS accelerometers and
gyroscopes are fabricated using very different processes" (id. at 3 [0014]).
As a result, the Specification informs, "[ a ]lmost all devices involving
magnetic sensors and MEMS inertial sensors are integrated with system in
package (SIP) methods using separate silicon chips." (Id.) A major problem
with providing both types of sensors on a single chip is said to be that a cap
wafer is bonded to the MEMS sensor or sensors "at high temperatures that
would damage components of the magnetic sensor." (Id. at 4 [0015].)
3 Application 14/861,886, Integrating diverse sensors in a single
semiconductor device, filed 22 September 2015. We refer to the
'"886 Specification," which we cite as "Spec."
2
Appeal 2018-004368
Application 14/861,886
The Specification reveals that these problems are overcome by
forming combined sensor package 150,4 illustrated in Figure 4, below .
100
\
' <' ' l !
! 1
100
)
100
124 ~"""""""""""""! 126
"''"'"'"'"'"'"'"'" I
34 62 5S
I l I ! i
\
160
32 62
i
'
.,--"150
t
56 52 30
100
i f ~~~~~
. 20
{Figure 4 shows dual sensor 150 comprising MEMS sensors 30, 32, and 34,
and magnetic sensors 124, 126, and 128}
MEMS device structure 22 comprises substrate layer 28 and structural
layer 76 within which sensors 30, 32, and 34 are formed (id. at 7 [0024]).
Device structure 22 is bonded by bonding layer 50 (id. at 5-6 [0021]) to
cap layer 24, which may include application specific integrated circuitry
("ASIC") for control, signal conditioning, and data management, etc.
(id. at 5 [0018]). Through-silicon vias ("TSV") 64 may be formed through
4 Throughout this Opinion, for clarity, labels to elements are presented in
bold font, regardless of their presentation in the original document.
3
Appeal 2018-004368
Application 14/861,886
the cap layer 24, filled with a conductor, and provided with appropriate
electrical contacts 68. (Id. at 6 [0023].) Oxide isolation layer 131 is then
deposited over cap layer 24 (id. at 15 [0047]), and magnetic sensors 124,
126, and 128 are fabricated on top of oxide isolation layer 131. (Id. at 3-
4 [0015]; 11-14 [0038]-[0043]; Figs 5-11 (not reproduced here.))
Claim 1 is representative and reads:
A method of manufacturing a sensor system [150] comprising:
forming a first structure [20] having
a substrate layer [28] and
a first sensor [30, 32, 34],
the first sensor being positioned on a first side [36] of
the substrate layer [28];
bonding [50] a cap structure [24] over
the first sensor [30] on the first side [36] of the substrate
layer [28];
depositing a first dielectric layer [131] over
the cap structure [24];
after bonding [50] the cap structure [24] and depositing
the first dielectric layer [131 ],
fabricating a second sensor [124, 126, 128]
on the first dielectric layer [131 ], wherein
the second sensor [124] includes components that
would be damaged at a temperature that is used to
bond [50] the cap structure [24]
to the first side [36] of the substrate layer [28].
(Claims App., Br. 14; some formatting, emphasis, and bracketed labels to
elements shown in the Figures added.)
Remaining independent claim 11 is similar, but includes the step, inter
alia, of forming a through-silicon via ("TSV"), a limitation that is also
recited in claim 2, which depends from claim 1.
4
Appeal 2018-004368
Application 14/861,886
The Examiner maintains the following grounds of rejection: 5, 6
A. Claims 1, 6-8, and 10 stand rejected under 35 U.S.C. § 103
in view of the combined teachings of Bowles, 7 Allegato, 8 and
Chung.9
Al. Claims 2-5, 9, and 11-15 stand rejected under 35 U.S.C.
§ 103 in view of the combined teachings of Bowles,
Allegato, Perruchot, 10 and Chung.
B. Discussion
The Board's findings of fact throughout this Opinion are supported by
a preponderance of the evidence of record.
Liu urges the Examiner erred harmfully because neither Allegato nor
Chung cures the failure of Bowles to teach or suggest that, after the cap layer
is bonded over the first sensor, a first dielectric layer is deposited over the
5 Examiner's Answer mailed 16 January 2018 ("Ans.").
6 Because this application was filed after the 16 March 2013, effective date
of the America Invents Act, we refer to the AIA version of the statute.
7 Phillip H. Bowles et al., Sensor package and method of forming same,
U.S. Patent Application Publication 2014/0015123 Al (16 January 2014)
(assigned to Freescale Semiconductor, Inc., the present real-party-in-
interest.)
8 Giorgio Allegato et al., Method for manufacturing a die assembly having a
small thickness and die assembly relating thereto, U.S. Patent
No. 9,327,964 B2 (3 May 2016), based on an application
filed 27 October 2014.
9 Young Sir Chung et al., Method for tunnel junction sensor with magnetic
cladding, U.S. Patent No. 7,444,738 B2 (2008).
10 Francois Perruchot et al., Method of forming an electromechanical
transducer device, U.S. Patent Application Publication 2012/0056308 Al
(2012). (Assigned in part to Freescale Semiconductor, Inc.; Lianjun Liu is
listed as a co-inventor.)
5
Appeal 2018-004368
Application 14/861,886
cap structure, and a second sensor is then fabricated on the first dielectric
layer. (Br. 11; Reply 11 2.) Liu argues that Bowles teaches bonding pre-
fabricated controller element 24 to MEMS sensor element 22, 12 and that
Allegato teaches bonding preformed first, second, and third wafers to one
another. Liu argues further that Chung teaches only that magnetic tunnel
junction magnetic sensors may be fabricated on a substrate. (Id.) Moreover,
according to Liu, "[ a ]lthough the substrate in Chung may include integrated
circuitry formed thereon, there is no teaching or suggestion that the substrate
in Chung is bonded to another wafer or other structure in Chung after the
MT J is formed." (J d.) Liu, emphasizing that the appealed claims are drawn
to a method of making sensors, not to the sensors themselves, concludes that
"none of the cited references, alone or together, disclose or suggest forming
a second sensor on a first dielectric layer after bonding a cap structure over
the first sensor." (Br. 13, last para.)
The Examiner responds that the disclosure by Allegato of "depositing
a first dielectric over the cap structure (FIG. 2: 42, see col. 2, line 43)"
(FR 3, 3d. para.) would have suggested modifying Bowles "such that 24 is
deposited as a first dielectric layer over the cap structure so as to provide
passivation between the cap and the second sensor" (Ans. 3, 1st full para,
citing FR 3.) Thus, the Examiner concludes, Chung's teachings would have
motivated the routineer "to fabricate such a second sensor on the first
11 Reply Brief filed 16 March 2018 ("Reply").
12 Liu acknowledges that the argument in the Brief should have referred to
sensor element 56, rather than element 24, but that sensor element 56 is also
prefabricated and then mounted on sensor 22, not fabricated on the dielectric
layer. (Reply 2.)
6
Appeal 2018-004368
Application 14/861,886
dielectric layer so as to form a magnetic sensor that can be easily integrated
into the semiconductor device." (Id.)
The fundamental flaw in the Examiner's argument is that proof of
enablement, i.e., that those skilled in the art would have known how to carry
out the claimed process with no teachings beyond those in the prior art of
record, is not proof that such persons would have gleaned from that prior art
a suggestion or motivation to perform the claimed process. Thus,
notwithstanding that Chung provides evidence that persons skilled in the art
knew how to fabricate magnetic sensors using magnetic tunneling junctions
("MTJ") and moveable magnetic field sources ("MPS") using manufacturing
methods well known for making semiconductors and integrated circuits-a
fact Liu does not appear to dispute-the Examiner has not shown that Chung
would have provided any suggestion or motivation to form such a sensor on
top of a sensor of a different type, such as an MEMS sensor. On the other
hand, neither Bowles nor Allegato suggests that the magnetic sensors be
formed on preformed MEMS sensors. Rather, both teach that preformed
magnetic sensors be mounted on the preformed MEMS sensors. The
Examiner does not make any findings regarding Perruchot that cure the
defects of the other references vis-a-vis the appealed claims.
A secondary flaw is that the Examiner appears to interpret the term
"fabricating," as used in claims 1 and 11, as including mounting preformed
magnetic sensors on the first dielectric layer. Terms used in the claims must
be interpreted, however, in light of the Specification, from the point of view
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Appeal 2018-004368
Application 14/861,886
of a person having ordinary skill in the art. 13 The '886 Specification makes
clear that the term "fabricating," in this context, means making by
semiconductor fabrication processes, as distinguished from mounting
preformed parts on substrates.
On the present record, the only suggestion for depositing a first
dielectric layer over a cap structure, and then fabricating a second sensor on
the first dielectric layer, is in the '886 Specification. But Appellant's own
disclosure is not prior art, and hindsight is not evidence on which a
conclusion of obviousness can be based.
We therefore reverse the appealed rejections.
C. Order
It is ORDERED that the rejection of claims 1-15 is reversed.
REVERSED
13 See, e.g., "What Phillips [v. AWH Corp., 415 F.3d 1303, 1321 (Fed.
Cir. 2005)] now counsels is that in the absence of something in the written
description and/or prosecution history to provide explicit or implicit notice
to the public-i.e., those of ordinary skill in the art-that the inventor
intended a disputed term to cover more than the ordinary and customary
meaning revealed by the context of the intrinsic record, it is improper to read
the term to encompass a broader definition simply because it may be found
in a dictionary, treatise, or other extrinsic source." Nystrom v. Trex Co.,
Inc., 424 F.3d 1136, 1145 (Fed. Cir. 2007).
8