Ex Parte JangJian et al

Patent Trial and Appeal Board

Oct 20, 2016

13415546 (P.T.A.B. Oct. 20, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/415,546 03/08/2012
43859 7590 10/24/2016
SLATER MATSIL, LLP
17950 PRESTON ROAD, SUITE 1000
DALLAS, TX 75252
FIRST NAMED INVENTOR
Shiu-Ko JangJian
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.
TSMll-1574 3912
EXAMINER
KILPATRICK, WARREN H
ART UNIT PAPER NUMBER
2896
NOTIFICATION DATE DELIVERY MODE
10/24/2016 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):
docketing@slatermatsil.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte SHIU-KO JANGJIAN, MIN HAO HONG,
KEI-WEI CHEN, and SZU-AN WU
Appeal2015-003791
Application 13/415,546
Technology Center 2800
Before TERRY J. OWENS, PETER F. KRATZ, and MONTE T. SQUIRE,
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, 3, 4, 6-10, 12, and 21-31. We have jurisdiction under
35 U.S.C. § 6(b).
The Invention
The Appellants' claimed invention is directed toward an image sensor
(Spec. i-f 8). Claims 1 and 21 are illustrative:
1. A structure comprising:
a semiconductor substrate;
a photo element in the semiconductor substrate; and
an isolation region in the semiconductor substrate
proximate the photo element, the isolation region comprising a
Appeal2015-003791
Application 13/415,546
Lee
l\1ouli
Park
He
dielectric material and an epitaxial region, the epitaxial region
being disposed between the semiconductor substrate and the
dielectric material, wherein the epitaxial region comprises a
material that is lattice mismatched to a substrate material of the
semiconductor substrate.
21. A structure comprising:
a semiconductor substrate;
a photo element comprising a p-n junction and extending
from a first side of the semiconductor substrate into the
semiconductor substrate;
a p-doped well adjacent to the p-njunction and extending
from the first side of the semiconductor substrate into the
semiconductor substrate; and
an isolation structure in the p-doped well, the isolation
structure comprising an epitaxial layer on a sidewall surface of
a trench and an isolation material on the epitaxial layer, at least
a first portion of the epitaxial layer being p-doped.
The References
US 7,638,347 B2
US 7 ,872,284 B2
Dec. 29, 2009
Jan.18,2011
US 8,119,439 B2 Feb. 21, 2012
US 2013/0037856 Al Feb. 14, 2013
(filed Dec. 7, 2011)
The Rejections
The claims stand rejected under 35 U.S.C. § 103 as follows: claims 1,
6-8, 21, 23-25, 29, and 31 over the combined disclosures of Lee and Mouli,
claims 3, 4, and 30 over Lee in view of He, claims 9, 10, 12, and 22 over the
combined disclosures of Lee, Mouli, and He and claims 26-28 over Mouli in
view of Lee and Park.
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Appeal2015-003791
Application 13/415,546
OPINION
We reverse the rejections. We need address only the independent
claims (1, 3, 8 and 21). 1
Claims 1and8
Claim 1 requires a semiconductor substrate having an isolation region
comprising an epitaxial region including a material that is lattice
mismatched to a substrate material of the semiconductor substrate. Claim 8
requires a substrate having on a surface of a trench in the substrate an
epitaxial layer comprising a material that is lattice mismatched to the
substrate.
Lee discloses a semiconductor substrate (203) including an isolation
trench (TREN) having on its surface a selective epitaxial growth (SEG)
channel stop layer (204) doped with p-type impurities which may include
boron, a thermal oxide layer (205) on the channel stop layer (204), and an
isolation material (206) filling the trench (TREN) inside the thermal oxide
layer (205) (col. 2, 11. 53---67; Fig. 2). The boron prevents an n-type
impurity-containing photodiode (207) in the substrate (203) from
overlapping with photoelectron trap sites generated in the substrate (203)' s
silicon lattice structures during trench formation (col. 1, 11. 39-54; col. 2,
1. 65 - col. 3, 1. 5).
Mouli discloses a pixel cell (200) comprising a strained silicon
layer (170) formed by depositing on a SiGe base layer (172) an Si
layer (174) whose Si atoms align with Si atoms in the SiGe base layer (174)
1 The Examiner does not rely upon Park for any disclosure that remedies the
deficiency in the references applied to the independent claims (Final
Act. 15-17).
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Application 13/415,546
such that biaxial strain is imparted on the Si atoms in the Si layer (174)
(col. 4, 11. 49---61 ). The strain increases carrier (electron and hole) mobilities
and electron flow and decreases resistance, thereby providing greater drive
current capabilities for imaging device transistors (col. 4, 11. 7-11, 63---66).
The Examiner asserts that "[t]he purpose of [Mouli's] structure
(whether on the planar surface or in a trench on the substrate) is to apply
compressive stress to the channel of the device" (Ans. 3).
The Examiner does not establish that Mouli' s strained silicon
layer (170), which is disclosed only as having strain within itself (col. 4,
11. 56---61 ), applies a compressive stress to the pixel cell (200)' s channel.
Nor does the Examiner establish that Mouli's disclosed benefits of the
strained silicon layer (170) (col. 4, 11. 7-19, 63---66), which extends between
but not within the shallow trench isolation regions (155; Fig. 3) (which
correspond to Lee's trench (TREN; Fig. 2), would be provided or even be
desirable if the layer were within Mouli' s shallow trench isolation
regions (155) or Lee's isolation trench (TREN).
Claim 3
Claim 3 requires a semiconductor substrate having an isolation region
including a dielectric material and an "epitaxial region comprising a doped
sub-region and an un-doped sub-region, wherein the un-doped sub-region is
disposed adjacent a semiconductor sidewall of the semiconductor substrate
and between the semiconductor substrate and the doped sub-region, the
doped sub-region being disposed adjacent the un-doped sub-region and
between the un-doped sub-region and the dielectric material."
He discloses a semiconductor device (200) comprising a
substrate ( 110) having therein a U-shaped recess (210) which is useful for
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Appeal2015-003791
Application 13/415,546
forming a source or drain region and has on its sidewalls a SiGe seed
layer (220), has on its bottom a first SiGe layer (230) which increases in Ge
content from its lower surface to its upper surface, and has on the first SiGe
layer (230) a second SiGe layer (240) with a Ge content which is greater
than that of the Si Ge seed layer (220), increases from its lower surface to its
upper surface and, at the interface between its lower surface and the first
Si Ge layer (230)'s upper surface, is equal to or greater than that of the first
SiGe layer (230) at that interface (i-fi-f 43, 52, 56). The second SiGe
layer (240) optionally can be p-doped with boron for forming a PMOS
source/drain region (i-f 59). The SiGe seed layer (220) can prevent boron
diffusion from the second SiGe layer (240), and the first SiGe layer (230)
can serve as a buffer layer between the bottom of the recess (210) and the
second SiGe layer (240) to reduce or eliminate stacking faults caused by the
large difference in Ge content between the bottom of the second Si Ge
layer (240) and the bottom of the recess (210) (i-fi-f 7, 60).
The Examiner argues that it would have been prima facie obvious to
one of ordinary skill in the art, in view of He, to form an undoped layer on
the outside of Lee's boron-doped channel stop layer (204) to prevent boron
diffusion from the channel stop layer (204) into the n-type photodiode
region (207) (Final Act. 5; Ans. 5).
Setting forth a prima facie case of obviousness requires establishing
that the applied prior art would have provided one of ordinary skill in the art
with an apparent reason to modify the prior art to arrive at the claimed
invention. See KSR Int'! Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007).
Lee discloses that the channel stop (204)' s boron prevents the
photodiode (207) including n-type impurities from overlapping with trap
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Appeal2015-003791
Application 13/415,546
sites generated in the substrate (203)'s silicon lattice structures during
trench formation (col. 1, 11. 39-54; col. 2, 1. 65 - col. 3, 1. 5). The Examiner
does not establish that Lee indicates a problem of boron diffusion from the
channel stop layer (204) into then-type photodiode region (207) such that an
undoped layer around Lee's channel stop layer (204) would perform a useful
function. Hence, the Examiner does not set forth the required apparent
reason for modifying Lee as proposed by the Examiner.
Claim 21
Claim 21 requires a p-doped well adjacent to a p-njunction.
The Examiner asserts that Mouli discloses "a p-doped well adjacent to
the p-n junction and extending from the first side of the semiconductor
substrate into the semiconductor substrate (see Fig. 3: 161, column 4,
lines 20-24)" (Final Act. 12).
That portion of Mouli discloses a substrate ( 160) including a p-type
well ( 161 ). The Examiner provides no explanation which establishes that
the p-doped well (161) is adjacent to the p-njunction (122/124) (col. 4,
11. 25-27; Fig. 3).
Thus, the Examiner has not established a prima facie case of
obviousness of the structure claimed in any of the Appellants' claims.
DECISION/ORDER
The rejections under 35 U.S.C. § 103 of claims 1, 6-8, 21, 23-25, 29
and 31 over the combined disclosures of Lee and Mouli, claims 3, 4 and 30
over Lee in view of He, claims 9, 10, 12 and 22 over the combined
disclosures of Lee, Mouli, and He and claims 26-28 over Mouli in view of
Lee and Park are reversed.
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Appeal2015-003791
Application 13/415,546
It is ordered that the Examiner's decision is reversed.
REVERSED
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