Ex Parte Sandhu

Board of Patent Appeals and Interferences

May 18, 2011

11257946 (B.P.A.I. May. 18, 2011)

UNITED STATES PATENT AND TRADEMARKOFFICE
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
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/257,946 10/24/2005 Gurtej S. Sandhu MI22-3020 2521
21567 7590 05/18/2011
Wells St. John P.S.
601 W. 1st Street #1300
Spokane, WA 99201
EXAMINER
MILLER, JR, JOSEPH ALBERT
ART UNIT PAPER NUMBER
1715
MAIL DATE DELIVERY MODE
05/18/2011 PAPER
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.
PTOL-90A (Rev. 04/07)

1 
 

UNITED STATES PATENT AND TRADEMARK OFFICE
_______________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_______________
Ex parte GURTEJ S. SANDHU
_______________
Appeal 2010-004567
Application 11/257,946
Technology Center 1700
________________
Before BRADLEY R. GARRIS, KAREN M. HASTINGS, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.
GARRIS, Administrative Patent Judge.

DECISION ON APPEAL
Appellant appeals under 35 U.S.C. § 134 from the Examiner's decision
rejecting claims 19-27 and 44-52. We have jurisdiction under 35 U.S.C. § 6.
We REVERSE.
Appellant claims a method of forming a field effect transistor gate oxide on
a substrate comprising chemisorbing a first metal-containing species monolayer 12
onto the substrate wherein the monolayer is discontinuously formed over the
substrate, exposing the substrate to a gaseous oxygen-containing second precursor
effective to react with the first metal-containing species to form a gate dielectric
Appeal 2010-004567
Application 11/257,946
 
second metal oxide monolayer 16 and effective to form an oxygen reaction product
with substrate material not covered by the first metal-containing species
monolayer, and exposing the substrate to a halogen-containing third gaseous
substance "to selectively remove the oxide reaction product from the substrate
relative to the gate dielectric second metal oxide monolayer (claim 19; Figs. 1-3).
Representative claims 19 and 44 read as follows:
19. A method of forming a field effect transistor gate oxide on a
substrate, comprising:
positioning a substrate within a deposition chamber;
chemisorbing a first metal-containing species monolayer onto the
substrate within the chamber from a gaseous first precursor, the first metal-
containing species monolayer being discontinuously formed over the substrate;
exposing the substrate having the discontinuous first metal-containing
species monolayer to a gaseous oxygen-containing second precursor different from
the first precursor effective to react with the first metal-containing species to form
a gate dielectric second metal oxide monolayer and effective to form an oxide
reaction product of the oxygen-containing second precursor with substrate material
not covered by the first metal-containing species monolayer; and
exposing the substrate having the gate dielectric second metal oxide
monolayer and the oxides reaction product to a halogen-containing third gaseous
substance different from the first and second precursors effective to selectively
remove the oxide reaction product from the substrate relative to the gate dielectric
second metal oxide monolayer.
44. A method of forming a semiconductor construction comprising:
providing a semiconductor substrate within a deposition chamber;
providing a first precursor into the chamber;
discontinuously chemisorbing a first species monolayer onto the
substrate;
providing a second precursor into the chamber;
Appeal 2010-004567
Application 11/257,946
 
reacting the second precursor within the first precursor monolayer to
form a second species monolayer and forming a reaction product with the substrate
from the second precursor in areas not covered by the first species monolayer; and
without depositing additional material, removing the reaction product
while retaining the second species monolayer.
The Examiner rejects claims 19, 20, 22-27, and 44-52 under 35 U.S.C.
§ 102(b) as anticipated by, or alternatively under 35 U.S.C. § 103(a) as
unpatentable over, Pomarede (US 2002/0098627 A1, published Jul. 25, 2002).
In addition, the Examiner rejects claims 19-26 and 44-50 under 35 U.S.C.
§ 103(a) as unpatentable over the Admitted Prior Art (APA) disclosed in the
Specification (Spec. paras. [0006]-[0009]) in view of Brabant (US 2003/0036268
A1, published Feb. 20, 2003).
The § 102/§ 103 Rejections based on Pomarede
Appellant argues that Pomarede contains no teaching or suggestion of the
claim 19 step "exposing the substrate . . . to a halogen-containing third gaseous
substance . . . to selectively remove the oxide reaction product from the substrate
relative to the gate dielectric second metal oxide monolayer" or the corresponding
claim 44 (see also claim 48) step "without depositing additional material, removing
the reaction product while retaining the second species monolayer" (App. Br. 9-10;
Reply Br. 2-3).
We agree with Appellant.
The Examiner considers these claim steps to be satisfied by Pomarede's step
of subjecting dielectric formation 120 to an excited species (e.g., halogen)
treatment 125 (Ans. 4 citing Pomarede paras. [0084], [0086], and [0087]).
However, this treatment exposes halogen to the dielectric (e.g., A12O3) monolayer
Appeal 2010-004567
Application 11/257,946
 
120 (e.g., see paras. [0068] and [0077]). The halogen of treatment 125 is not
exposed to a reaction (e.g., oxidation) product with the substrate which is thereby
selectively removed as required by the independent claims on appeal.
In this regard, we recognize that the Examiner believes an oxide reaction
product with the substrate is necessarily formed during the pulse cycles which
generate the dielectric monolayer (Ans. 5, 10). Whether the Examiner's belief is
correct or not, the fact remains that the ultimate product generated by these pulse
cycles is the dielectric monolayer, and it is this monolayer which is exposed to a
halogen during the excited species treatment of Pomarede. This record provides no
support for the Examiner's implicit proposition that the ultimate product of
dielectric formation 120 in Pomarede's method includes a reaction (e.g., oxidation)
product with the substrate which is selectively removed by halogen exposure
during excited species treatment 125.
For these reasons, we cannot sustain the § 102/§ 103 rejections based on
Pomarede.
The § 103 Rejection based on the APA and Brabant
The Examiner acknowledges that the APA method contains no step of
selectively removing reaction product from the substrate as required by the
independent claims (Ans. 8). Concerning this deficiency, the Examiner finds that
Brabant teaches using HF vapor to remove an oxide layer from a silicon substrate
and concludes that
[i]t would have been obvious to someone of ordinary skill
in the art at the time of the invention to apply the use of an
HF gas treatment as taught by Brabant to applicants [sic]
admitted prior art of forming a non-continuous film on the
surface of a substrate wherein a second film-forming steps
Appeal 2010-004567
Application 11/257,946
 
[sic] results in a native oxide on the substrate as a known
method of removing a layer of native oxide which would
result in a purer surface
(id.).
Appellant argues that Brabant contains no teaching or suggestion of
selectively removing reaction (e.g., oxidation) product from the APA substrate as
required by the independent claims (App. Br. 10; Reply Br. 3).
Appellant's argument is persuasive.
It is undisputed that Brabant's teaching is limited to removal of native oxide
which tends to form on an unprocessed silicon substrate. This limited teaching
would not have suggested that the HF of Brabant would selectively remove oxide
reaction product from the APA substrate while retaining the desired (e.g., A12O3)
monolayer on the substrate. These circumstances indicate that the Examiner's
obviousness conclusion is based on hindsight. This indication is reinforced by the
Examiner's reliance on Appellant's own Specification disclosure as "support for the
fact that HF has selectivity for other oxides over aluminum oxides" (Ans. 12).
It follows that we also cannot sustain the § 103 rejection based on APA and
Brabant.
Conclusion
The decision of the Examiner is reversed.
REVERSED

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