Ex Parte Beasom

Board of Patent Appeals and Interferences

Nov 30, 2009

10944234 (B.P.A.I. Nov. 30, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte JAMES D. BEASOM
____________

Appeal 2009-006920
Application 10/944,234
Technology Center 2800
____________

Decided: November 30, 2009
____________

Before BRADLEY R. GARRIS, ADRIENE LEPIANE HANLON, and
PETER F. KRATZ, Administrative Patent Judges.
KRATZ, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on an appeal under 35 U.S.C. § 134 from the
Examiner’s final rejection of claims 1 and 3-6. We have jurisdiction
pursuant to 35 U.S.C. § 6.

Appeal 2009-006920
Application 10/944,234

2
Appellant’s claimed invention is directed to a method of forming an
NPN transistor base region.1 Appellants’ method includes the steps of
diffusing boron dopants through a substrate working surface select region
and, thereafter, implanting indium dopants through the select region of the
substrate surface. A peak concentration of indium dopants is formed deeper
from the working surface than a peak concentration of the boron dopants.
Claim 1 is illustrative and reproduced below:
1. A method of forming a base region in an NPN transistor, the
method comprising:

diffusing Boron dopants through a select region of working surface of
a substrate; and

implanting Indium dopants through the select region of the working
surface of the substrate after diffusing the Boron dopants, wherein a peak
concentration of Indium dopants are formed deeper from the working
surface of the substrate than a peak concentration of the Boron dopants.

The Examiner relies on the following prior art references as evidence
in rejecting the appealed claims:
Chen 5,185,276 Feb. 9, 1993
Johansson 6,459,140 B1 Oct. 1, 2002

Claims 1, and 3-6 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Chen in view of Johansson.
We affirm the stated rejection for substantially the reasons set forth in
the Examiner’s Answer. We offer the following for emphasis.

1 Appellant notes that “[a] bipolar NPN transistor is made of a N type
emitter, a P type base, and a N type collector” (Spec. ¶ 0003).
Appeal 2009-006920
Application 10/944,234

3
Appellant argues claims 1, and 4-6 together as a group and presents
additional argument with respect to dependent claim 3 (see generally App.
Br.). Accordingly, we select sole independent claim 1 as a representative
claim on which we decide this appeal as to the commonly argued and
grouped claims. Additionally, we consider claim 3 separately to the extent
separately argued.

PRINCIPAL ISSUES
Has Appellant established reversible error in the Examiner’s
determination that the combined teachings of Chen and Johansson would
have rendered the claimed subject matter obvious to one of ordinary skill in
the art by arguing that neither reference teaches or suggests (1) the locations
of peak dopant concentrations called for in claim 1 and/or (2) the boron
Gaussian profile together with the location of the peak boron concentration,
as required by claim 3?

PRINCIPLES OF LAW
Appellants have the burden on appeal to the Board to demonstrate
error in the Examiner's position. See In re Kahn, 441 F.3d 977, 985-86 (Fed.
Cir. 2006) (“On appeal to the Board, an applicant can overcome a rejection
[under § 103] by showing insufficient evidence of prima facie obviousness
or by rebutting the prima facie case with evidence of secondary indicia of
nonobviousness.”) (quoting In re Rouffet, 149 F.3d 1350, 1355 (Fed. Cir.
1998)); see also 37 C.F.R. § 41.37(c)(1)(vii).
“Section 103 forbids issuance of a patent when ‘the differences
between the subject matter sought to be patented and the prior art are such
Appeal 2009-006920
Application 10/944,234

4
that the subject matter as a whole would have been obvious at the time the
invention was made to a person having ordinary skill in the art to which said
subject matter pertains.’” KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 406
(2007) (quoting 35 U.S.C. § 103(a)).
“What matters is the objective reach of the claim. If the claim extends
to what is obvious, it is invalid under § 103.” KSR, 550 U.S. at 419 (2007).

FINDINGS OF FACT/ANALYSIS
The Examiner has found that:
Johansson teaches a method of forming a base
region in a bipolar transistor (Figs. 5-7), wherein
boron and indium doping profiles are combined to
form the base of an NPN transistor, in order to
preserve most of the properties of boron-base
transistors, while improving some parameters with
the addition of indium dopants (col. 3: Ins. 1-9,
col. 2: Ins. 36-59).
Ans. 4.
Appellant does not specifically contest this determination of the
Examiner (see generally App. Br. and Reply Br.).
Moreover, Appellant does not argue with the Examiner’s
determination that the combined teachings of Chen and Johansson would
have taught or suggested diffusing boron dopants through a select portion of
a substrate working surface and subsequently implanting indium through the
substrate working surface portion (Ans. 3-4; see generally App. Br. and
Reply Br.). In this regard, the Examiner has found that Chen teaches or
suggests a boron diffusion step followed by an indium implant step in
forming a base region of an NPN transistor (Ans. 3; Chen, col. 4, ll. 35-53,
col. 5, ll. 16-21, and Figs. 1-3).
Appeal 2009-006920
Application 10/944,234

5
Rather, Appellant urges that neither of the applied references teach or
suggest the relative locations of peak indium dopant concentration and peak
boron dopant concentration as required by representative independent claim
1 and as disclosed by Appellant (App. Br. 5). Concerning representative
claim 1, Appellant maintains that even though Johnson “suggests that the
Indium dopants be present in the collector base depletion region, nothing in
the reference indicates a peak Indium dopant concentration being present in
that region yet alone peak dopant concentrations of Indium and Boron being
positioned in relation to each other as is claimed in claim 1. . . .” Id.
We do not find this argument persuasive of reversible error in the
stated rejection. As explained by the Examiner,
the limitation of having a peak concentration of Indium
dopants formed deeper than a peak concentration of Boron
dopants, would have been considered obvious to one skilled in
the art, since Johansson recognizes the advantageous properties
of both boron-base transistors and indium-based transistors
(col. 1: Ins. 31-67, col. 2: Ins. 36-67, col. 3: Ins. 1-9), and
states that his "double profile" transistor will exhibit improved
beta-Early voltage and lower temperature dependence of beta,
while preserving the advantageous properties, such as low
resistance, of boron-base transistors.
Ans. 4.
The Appellant has failed to direct us to any error in the Examiner’s
position. Moreover, we find that it is reasonable to expect that the double
profile for the indium and boron dopants taught or suggested by Johansson
would certainly have led one of ordinary skill in the art to a transistor with a
Appeal 2009-006920
Application 10/944,234

6
peak concentration2 of indium dopants that is located deeper, shallower, or
of identical depth with the peak concentration of the boron dopants. While
Appellant urges that it would not have been predictable to select the dopant
profiles such that the peak concentration of indium would have been deeper
than the peak concentration of boron, Appellant does not persuasively
explain or substantiate why such a choice for the double profile transistor
taught by Johansson would have been beyond the routine skill of one of
ordinary skill in the art, particularly given the limited options for the relative
dopant concentration depth profiles available for selection. In this regard,
we note that Chen teaches that implantation energy and dose can be used to
adjust dopant profile (col. 6, ll. 37-39).
Consequently, based on the record before us, we agree with the
Examiner that “it would have been obvious to one of ordinary skill in the art
at the time of the invention, to combine the teaching of Johansson with the
teaching of Chen, in order to form the peak concentration of indium dopants
deeper than the peak concentration of boron dopants.” See Ans. 4.
As a final point, we note that Appellant has not demonstrated
unexpected results for the claimed process based on any entered evidence
identified in the Appeal Brief.3
Concerning dependent claim 3, Appellant further argues that neither
of the applied references teach or suggest a Gaussian profile for boron with a

2 We note that representative claim 1 does not limit the dopant peak
concentrations to any particular absolute concentration values and/or any
particular depths for both dopants.
3 Appellant states “[t]here is nothing to present in the Evidence Appendix”
(App. Br., Evid. Appendix).
Appeal 2009-006920
Application 10/944,234

7
peak concentration approximate4 the substrate working surface or that such a
doping profile would be predictable (App. Br. 6 and 7: Reply Br. 3 and 4).
This argument is not convincing because Appellant has not
persuasively substantiated why the Examiner’s rejection is overcome by this
argument. In this regard, the Examiner found that the boron dopant of the
applied prior art would display a profile, such as a Gaussian profile,
substantially similar to that of Appellant’s boron profile based on the
substantial similarity in the method of supplying the boron dopant of the
applied prior at, such as taught by Chen, to the doping methods disclosed by
Appellant. For example, Chen, like Appellant, discloses or suggests that ion
implantation and/or diffusion can be used in providing dopants (Chen, col. 4,
ll. 38-41; Spec. ¶¶ 0011-13, 0016, and 0028).
Appellant does not specifically dispute the Examiner’s determination
concerning the substantial identity of the boron introduction method of the
applied references and the boron implant method of Appellant (Ans. 7; see
generally App. Br. and Reply Br.). Rather, Appellant focuses on an alleged
incorrect reference to product similarities by the Examiner and an alleged
incorrect citation to case law and the Manual of Patent Examining Procedure
(M.P.E.P) by the Examiner.
However, the mere recitation of an alleged newly discovered product
characteristic or property (Gaussian boron profile characteristic and relative
location thereof) that is obtained via the claimed process does not cause
claims drawn thereto to patentably distinguish over the prior art which,

4 The claim term “approximate” is not defined in Appellant’s Specification
and is conditionally construed as rendering claim 3 open to encompassing a
reasonably wide latitude of peak concentration locations relative to the
substrate surface so long as the indium dopant peak concentration is deeper.
Appeal 2009-006920
Application 10/944,234

8
undisputedly, discloses substantially the same process. See In re Best, 562
F.2d 1252, 1255 (CCPA 1977).
Thus, we are not persuaded that Appellant’s unsubstantiated
assertions demonstrate reversible error in the obviousness rejection of
dependent claim 3.

CONCLUSION
Appellant has not established reversible error in the Examiner’s
determination that the combined teachings of Chen and Johansson would
have rendered the claimed subject matter obvious to one of ordinary skill in
the art by arguing that neither reference teaches or suggests (1) the locations
of peak dopant concentrations called for in claim 1, and/or (2) the boron
Gaussian profile together with the location of the peak boron concentration,
as required by claim 3.

ORDER
The Examiner’s decision to reject claims 1 and 3-6 under 35 U.S.C.
§ 103(a) as being unpatentable over Chen in view of Johansson is affirmed.
Appeal 2009-006920
Application 10/944,234

9
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 CFR § 1.136(a)(1)(iv).

AFFIRMED

cam

FOGG & POWERS LLC
5810 W 78TH STREET
SUITE 100
MINNEAPOLIS, MN 55439