Ex Parte Horsky et al

Board of Patent Appeals and Interferences

May 20, 2009

10251491 (B.P.A.I. May. 20, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte THOMAS NEIL HORSKY,
DALE CONRAD JACOBSON, and WADE ALLEN KRULL
____________

Appeal 2009-001049
Application 10/251,4911
Technology Center 2812
____________

Decided:2 May 20, 2009
____________

Before CHUNG K. PAK, JEFFREY T. SMITH, and MARK NAGUMO,
Administrative Patent Judges.

NAGUMO, Administrative Patent Judge.

1 Application 10/251,491, Method of Manufacturing CMOS devices by the
Implantation of N- and P-type Cluster Ions, filed 20 September 2002,
claiming the benefit of an application filed 16 September 2002, provisional
applications filed 26 June 2002, and (in part) an application filed
13 December 2000. The specification is referred to as the
“491 Specification,” and is cited as “Spec.” The real party in interest is
listed as SemEquip, Inc. (Applicants’ Brief on Appeal, filed 14 April 2006
(“Br.”), 3.)
2 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, begins to run from the Decided Date
shown on this page of the decision. The time period does not run from the
Mail Date (paper delivery) or Notification Date (electronic delivery).
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Application 10/251,491

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DECISION ON APPEAL
A. Introduction
Thomas Neil Horsky, Dale Conrad Jacobson, and Wade Allen Krull
(“Horsky”) timely appeal under 35 U.S.C. § 134(a) from the final rejection3
of claims 118-144. We have jurisdiction under 35 U.S.C. § 6.
We AFFIRM.
The subject matter on appeal relates to a method of implanting cluster
ions into a substrate. The method is said to be particularly useful for making
Ultra-Shallow Junctions (“USJ”) in CMOS devices. According to the
491 Specification, the cluster ions, such as N-type cluster ions As4Hx+ and P-
type cluster ions B10Hx-, enable relatively large amounts of dopant to be
implanted at a relatively low current. The problems of wafer charging and
low productivity associated with relatively low energy ion implantation are
said to be avoided. (Spec. 11, ¶¶ [0015]-[0016].)
Representative Claim 118 is reproduced from the Claims Appendix to
the Principal Brief on Appeal:
118. A method of implanting dopant materials into a substrate,
the method comprising the steps of:
(a) generating N- type cluster ions from a first molecular
species;
(b) generating P- type cluster ions from a second
molecular species;
(c) implanting said N- type cluster ions into a first region
on a substrate; and

3 Office action mailed 25 August 2004 (“Final Rejection”; cited as “FR”).
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(d) implanting said P-type cluster ions into a second
region on said substrate.
(Claims App., Br. 10; indentation added.)
Claims 119-144 further limit various species of gases or cluster ions to be
used in step (a).
The Examiner has maintained the following grounds of rejection:4
A. Claim 118 stands rejected under 35 U.S.C. § 103(a) in view of
the combined teachings of Yeap5 and Bruel.6
B. Claims 119-144 stand rejected under 35 U.S.C. § 103(a) in
view of the combined teachings of Yeap, Bruel, and Saito.7
Horsky contends the Examiner erred by failing to show that the
references themselves suggest that the teachings of the references be
combined. (Br. 7.) Moreover, in Horsky’s view, the rejections are in error
because neither Yeap nor Bruel suggests that both N-type and P-type cluster
ions be implanted onto the same substrate. (Id.) Horsky argues further that
Saito does not cure the deficiencies of Yeap or Bruel, and that Saito actually
teaches away from the implantation of cluster ions implanted into separate
regions of a substrate. (Id. at 8.)

4 Examiner’s Answer mailed 26 May 2006. (“Ans.”).
5 Geoffrey Choh-Fei Yeap et al., CMOS Optimization Method Utilizing
Sacrificial Sidewall Spacer, U.S. Patent 6,093,594 (2000).
6 Michel Bruel, Process for Fast Droping [sic: Doping] of Semiconductors,
U.S. Patent 4,370,176 (1983).
7 Shuichi Saito, Method for Producing Shallow Junction in Surface Region
of Semiconductor Substrate using Implantation of Plasma Ions,
U.S. Patent 5,561,072 (1996).
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The Examiner maintains that a person having ordinary skill in the art
would have used the ion cluster implantation method taught by Bruel to
implant N-type and P-type dopants into silicon substrates to form junctions
as taught by Yeap. (Ans. 3.) The Examiner argues further that it would
have been obvious to use the gases taught by Saito for doping to make
cluster ions as taught by Bruel, and to use those cluster ions in the doping
steps taught by Yeap. (Id. at 3-4.)
B. Findings of Fact
Findings of fact throughout this Opinion are supported by a
preponderance of the evidence of record.
1. Yeap describes methods of manufacturing submicron scale CMOS
circuits. (Yeap, col. 1, ll. 5-10.)
2. Yeap describes implanting an N-type dopant into a silicon substrate to
form shallow source and drain extension junctions 28 and 30. (Yeap, col. 3,
l. 66, to col. 4, l. 2; Figure 3.)
3. Yeap describes implanting a P-type dopant into the same silicon
substrate to form shallow source and drain extension junctions 48 and 50.
(Yeap, col. 4, ll. 42-45; Figure 10.)
4. Yeap notes that, for sub-100 nanometer devices, special measures are
necessary to produce sufficiently shallow extension junctions 48 and 50.
(Yeap, col. 6, ll. 10-15.)
5. Bruel describes methods for the “fast doping” of semiconductors.
(Bruel, col. 1, ll. 7-8.)
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6. According to Bruel, in one embodiment, the process of doping is
accomplished by doping with a beam of polyatomic clusters, “generally
known as ‘clusters.’” (Bruel, col. 3, ll. 12-14.)
7. In Bruel’s words, “[a]ccording to a third variant, the cluster beam is
obtained by a supersonic expansion of vapour through a nozzle in vacuo.”
(Bruel, col. 3, ll. 21-23.)
8. Bruel teaches that the described process of doping “may be used for
doping any type of semiconductors, using any type of dopant material,” and
that the quantities of dopants (“impurities”) introduced in the substrate may
be easily controlled. (Bruel, col. 3, ll. 34-38.)
9. Bruel notes that “the use of a cluster beam leads to doping at a
microscopic level (a few tens of Ångstroms to a few thousands of
Ångstroms).” (Bruel, col. 5, ll. 6-9.)
10. Bruel cites several articles in the technical literature for methods of
making cluster beams (Bruel, col. 5, ll. 40-50, and for ion collective
acceleration (Bruel, col. 6, ll. 17-25).
11. According to Saito, higher density dynamic random access memories
require MOS transistors having diffused junctions that are formed at
shallower and shallower depths. (Saito, col. 1, ll. 11-19.)
12. Saito states that shallow doping of impurities remains (in 1994) a
problem (Saito, col. 1, ll. 20-22 and ll. 32-33), and describes a method for
forming shallow junctions (id. at col. 3, ll. 23-35.)
13. Saito teaches that dopants may be provided by generating a plasma in
gases such as B2H6, BF3, PH3, PF5, AsH3, or the like, and accelerating the
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ions to implant them in the surface region of the semiconductor substrate.
(Saito, col. 2, ll. 46-52.)
C. Discussion
As the Appellant, Horsky bears the procedural burden of showing
harmful error in the Examiner’s rejections. See, e.g., 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”) (citation and internal quote omitted).
Horsky’s argument that the references themselves must suggest that
the teachings of the references be combined is without merit as it fails to
recognize that persons having ordinary skill in the art bring their knowledge
and ordinary creativity to solve problems before them. As the Supreme
Court explained the need for a teaching, suggestion, or motivation to
combine elements of the prior art, “our precedents make clear, . . . , the
analysis need not seek out precise teachings directed to the specific subject
matter of the challenged claim, for a court can take account of the inferences
and creative steps that a person of ordinary skill in the art would employ.”
KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007). Moreover,
Horsky’s insistence that the rejection must be reversed because neither
reference teaches or suggests that both N-type and P-type cluster ions be
implanted in the same substrate is misguided because it demands
anticipation.
The Examiner concluded that it would have been obvious to use the
cluster-ion method of doping substrates, taught by Bruel, to form the shallow
N-type and P-type source and drain extension junctions in the same
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substrate, as taught by Yeap. This is no more than concluding that it would
have been obvious to use another disclosed technique to perform steps in a
known process. Horsky has not explained any fault in the Examiner’s
reasoning. We note that Yeap,8 Bruel,9 and Saito10 each indicate a need for
shallow and small scale doping, further supporting the Examiner’s
conclusion. Nor has Horsky shown that it would have been beyond the skill
of the ordinary worker to adapt Bruel’s teachings to the process taught by
Yeap. Similarly, the Examiner relied on Saito as evidence that various gases
were known as sources of atoms for N-type and P-type doping. Horsky’s
complaint that Saito teaches away from cluster ions by teaching only single
ions is legally incorrect. To “teach away” from using or doing something, a
reference must state that it “should not” or “cannot” be so used. Cf. Para-
Ordnance Manufacturing, Inc. v. SGS Importers International, Inc., 73 F.3d
1085, 1090 (Fed. Cir. 1995). Under the correct test, Saito does not teach
away from using cluster ions. Moreover Horsky misses the point that the
Examiner concluded that it would have been obvious to use such gases in the
method of forming cluster ions taught by Bruel, and hence to use those
cluster ions in the process taught by Yeap. Moreover, Horsky has not
explained why one of ordinary skill in the art would not have been able to
adapt, with a reasonable expectation of success, Bruel’s methods of making
cluster ions for use with the gases disclosed by Saito.

8 Yeap, col. 6, ll. 10-15; FF 4.
9 Bruel, col. 5, ll. 6-9; FF 9.
10 Saito, col. 1, ll. 1, ll. 11-20 and col. 3, ll. 23-35; FF 12 and 13.
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Horsky has not directed our attention to any credible evidence in the
record that it would have been beyond the skill of the person having ordinary
skill in the relevant arts. Thus, the Examiner has established a prima facie
case of obviousness. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007)
(“If a person of ordinary skill can implement a predictable variation, § 103
likely bars its patentability.”). Moreover, Horsky did not, in its Principal
Brief on Appeal, come forward with arguments explaining why unexpected
results rebut the prima facie case of obviousness. We conclude that Horsky
has failed to demonstrate harmful error in the Examiner’s rejections.
D. Order
We AFFIRM the rejection of claim 118 under 35 U.S.C. § 103(a) in
view of the combined teachings of Yeap and Bruel.
We AFFIRM the rejection of claims 119-144 under
35 U.S.C. § 103(a) in view of the combined teachings of Yeap, Bruel, and
Saito.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED

Appeal 2009-001049
Application 10/251,491

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PL Initial:
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