Ex Parte Eshun et al

Patent Trial and Appeal Board

Apr 17, 2018

13654161 (P.T.A.B. Apr. 17, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/654, 161 10/17/2012
23494 7590 04/19/2018
TEXAS INSTRUMENTS IN CORPORA TED
P 0 BOX 655474, MIS 3999
DALLAS, TX 75265
FIRST NAMED INVENTOR
Ebenezer Eshun
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.
TI-71462 9557
EXAMINER
TIJNGE, BRYAN R.
ART UNIT PAPER NUMBER
2897
NOTIFICATION DATE DELIVERY MODE
04/19/2018 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):
uspto@ti.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte EBENEZER ESHUN, HIMADRI SEKHAR PAL,
and AMITABH JAIN
Appeal2017-008024
Application 13/654,161
Technology Center 2800
Before TERRY J. OWENS, CHRISTOPHER C. KENNEDY, and
SHELDON M. McGEE, 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 1-20. We have jurisdiction under 35 U.S.C. § 6(b).
The Invention
The Appellants claim a method for forming an integrated circuit.
Claim 1 is illustrative:
1: A method of forming an integrated circuit, comprising
the steps of:
providing a substrate comprising a semiconductor;
forming a lightly doped drain (LDD) implant masking
layer;
Appeal2017-008024
Application 13/654,161
using the LDD implant masking layer, implanting LDD
dopants into said substrate to form LDD implanted regions
adjacent to a gate in an area for a metal oxide semiconductor
(MOS) transistor;
using the LDD implant masking layer, implanting halo
dopants at an angle into said substrate to form halo implanted
regions adjacent to said gate and extending past said LDD
implanted regions;
using the LDD implant masking layer, performing an
angled carbon implant which implants carbon ions at an angle
into said substrate to form angled carbon implanted regions
adjacent to said gate and extending past said LDD implanted
regions at a surface of the substrate;
using the LDD implant masking layer, performing a
plurality of zero-degree carbon implants which implant carbon
ions at different doses and/or energies substantially
perpendicular to said top surface of the substrate into said
substrate to form non-angled carbon implanted regions adjacent
to said gate; and
after performing the plurality of zero-degree carbon
implants, removing the LDD implant masking layer.
The References
Hoentschel
Lee (Lee '095)
Momiyama
Ohta
US 2007 /0252205 Al
US 7,573,095 B2
US 7 ,592,243 B2
US 2010/0003798 Al
US 2010/0105185 Al
US 2010/0279479 Al
US 7 ,888,223 B2
Nov. 1, 2007
Aug. 11, 2009
Sept. 22, 2009
Jan. 7,2010
Apr. 29, 2010
Nov. 4, 2010
Feb. 15, 2011
Apr. 5, 2012
Ku
Hat em
Lee (Lee '223)
Tsai US 2012/0083090 Al
The Re} ections
The claims stand rejected under 35 U.S.C. § 103 as follows: claims 1,
3---6, 9, and 10 over Lee '223 in view of Momiyama, Ku and Hatem, claim 2
over Lee '223 in view of Momiyama, Ku, Hatem and Ohta, claims 1 and 7
over Tsai in view of Momiyama, Ku and Hatem, claim 8 over Tsai in view
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Appeal2017-008024
Application 13/654,161
of Momiyama, Ku, Hatem and Lee '095, claims 11 and 13-20 over Lee '095
in view of Hoentschel, Momiyama, Lee '223 and Hatem, and claim 12 over
Lee '095 in view of Hoentschel, Momiyama, Lee '223, Hatem and Ohta.
OPINION
We reverse the rejections. We need address only the independent
claims (1 and 11 ). Those claims require performing a plurality of
zero-degree carbon implants substantially perpendicular to the top surface of
a substrate using an LDD implant masking layer used to implant carbon ions
at an angle into the substrate.
To meet that claim requirement in the rejections of claim 1 over
Lee '223 in view of Momiyama, Ku and Hatem and claim 11 over Lee '095
in view of Hoentschel, Momiyama, Lee '223 and Hatem, the Examiner
relies upon the combined disclosures of Lee '223 and Momiyama (Final
Act. 4--5, 11-14; Ans. 3--4, 7-8).
Lee '223 co-implants carbon ions at an implantation angle of about 0-
30Q before forming a source/drain extension region (110), and co-implants
carbon ions at an implantation angle of 0 degree before forming a
source/drain region (120) (col. 6, 11. 24--58).
Momiyama uses a resist mask (7) to form pocket regions (11 ),
n-diffused regions (12) (having carbon ions implanted at a 0-30Q tilt angle)
and extension regions (13) in an n-type element active region (3), removes
the resist mask (7), uses a resist mask (8) to form pocket regions (14),
n-diffused regions (15) (having carbon ions implanted at a 0-1 OQ tilt angle)
and extension regions (16) in a p-type element active region ( 4 ), removes the
resist mask (8), uses a resist mask (not shown) to expose only then-type
element active region (3), implants n-type impurity ions into the n-type
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Appeal2017-008024
Application 13/654,161
element active region (3) to form deep source/drain regions (17), removes
the resist mask, uses a resist mask (not shown) to expose only the p-type
element active region ( 4), and implants p-type impurity ions into the p-type
element active region (4) to form deep source/drain regions (18) (col. 6,
11. 25-59; col. 7, 1. 38- col. 8, 1. 66; Figs. 1B-4C).
Establishing a prima facie case of obviousness requires an apparent
reason to modify the prior art as proposed by the Examiner. See KSR Int 'l
Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007).
The Examiner finds that "Momiyama discloses using the LDD
masking layer for the carbon implant, which Lee '223 discloses is a two part
implant, one angled and one zero degrees. Therefore the combined
teachings of Lee '223 and Momiyama clearly suggest performing an angled
carbon implant and a zero degree carbon implant using the same LDD
implant masking layer" (Ans. 3--4).
Lee '223's zero-degree implant is used to form the source/drain
region (120). The Examiner does not establish that Momiyama's use of
resist layers other than the LDD masking layers (7, 8) to form the
source/drain regions (17, 18) would have provided one of ordinary skill in
the art with an apparent reason to use an LDD masking layer to form
Lee '223 's source/drain regions (120).
In the rejection of claim 1 over Tsai in view of Momiyama, Ku and
Hatem, the Examiner relies upon the combined disclosures of Tsai and
Momiyama to meet the Appellants' claim requirement of performing a
plurality of zero-degree carbon implants substantially perpendicular to the
top surface of a substrate using an LDD implant masking layer used to
implant carbon ions at an angle into the substrate (Final Act. 7-8).
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Appeal2017-008024
Application 13/654,161
Tsai forms an LDD region (24) by doping a silicon substrate (11) with
a light concentration of an n-type dopant at each of two sides of a gate
structure (18) using the gate structure (18) and an adjacent spacer (14) as a
mask, then forms an SiC region (26) and a source/drain region (12) in the
silicon substrate (11) at each of the two sides of the gate structure (18), the
SiC region (26) having a second portion (28) with a higher SiC
concentration than a first portion (27), by implanting carbon atoms at a
normal angle and a tilt angle into a silicon substrate ( 11) and, after an n-type
dopant for forming the source/drain region (12) is implanted into the silicon
substrate (11) at each of the two sides of the gate structure (18), annealing to
form crystalline SiC and simultaneously form the source/drain region (12)
(i-f 22; Fig. 2). "Since the implantation angle is tilted, the carbon atoms can
reach the position 44 under the LDD regions 24" (i-f 22; Fig. 7).
The Examiner finds that 1) Momiyama's "LDD masking layer 7 is
suitable for both angled and zero degree implants. Momiyama discloses
using the LDD masking layer for the carbon implant, which Tsai discloses is
a two part implant, one angled and one zero degrees. Therefore the
combined teachings of Tsai and Momiyama clearly suggest performing an
angled carbon implant and a zero degree carbon implant using the LDD
implant masking layer" (Ans. 6), and 2) "the sequence disclosed by Tsai,
implanting carbon before forming source/drain regions, enables one to use
the same mask for the zero degree carbon implant as for the LDD, halo, and
angled carbon implant previously carried out" (id.).
The Examiner does not establish that Momiyama's use of different
masks to form the carbon-implanted n-diffusion regions (12, 15) and the
source/ drain regions ( 17, 18) would have provided one of ordinary skill in
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Application 13/654,161
the art with an apparent reason to use Tsai's LDD (24)-forming mask (gate
structure 18/first spacer 14) when implanting carbon atoms at a normal angle
and a tilt angle into the SiC (26) and source/drain (12) regions.
Accordingly, we reverse the rejections.
DECISION/ORDER
The rejections under 35 U.S.C. § 103 of claims 1, 3---6, 9, and 10 over
Lee '223 in view of Momiyama, Ku and Hatem, claim 2 over Lee '223 in
view of Momiyama, Ku, Hatem and Ohta, claims 1 and 7 over Tsai in view
of Momiyama, Ku and Hatem, claim 8 over Tsai in view of Momiyama, Ku,
Hatem and Lee '095, claims 11 and 13-20 over Lee '095 in view of
Hoentschel, Momiyama, Lee '223 and Hatem, and claim 12 over Lee '095 in
view of Hoentschel, Momiyama, Lee '223, Hatem and Ohta are reversed.
It is ordered that the Examiner's decision is reversed.
REVERSED
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