Ex Parte Sato et al

Board of Patent Appeals and Interferences

Oct 27, 2009

11016997 (B.P.A.I. Oct. 27, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte HIDENORI SATO and DAISUKE HAYASHI
____________

Appeal 2009-008133
Application 11/016,997
Technology Center 1700
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Decided: October 27, 2009
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Before CATHERINE Q. TIMM, BEVERLY A. FRANKLIN, and
LINDA M. GAUDETTE, Administrative Patent Judges.

GAUDETTE, Administrative Patent Judge.

DECISION ON APPEAL

Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
decision finally rejecting claims 1-6, 13-15, 19, and 20 (Final Office Action
Appeal 2009-008133
Application 11/016,997

(“Final”), mailed Jan. 14, 2008, 1).1 We have jurisdiction under 35 U.S.C.
§ 6(b).
We REVERSE.
STATEMENT OF THE CASE
Independent claims 1 and 13 are illustrative of the subject matter on
appeal, and are reproduced from the Claims Appendix to the Appeal Brief
(“Br.”), filed Oct. 16, 2008:
1. A magnetron plasma processing apparatus comprising:

an airtight processing chamber for accommodating therein a substrate
to be processed;

a gas supply unit for supplying a processing gas into the processing
chamber;

a gas exhaust unit for exhausting an inside of the processing chamber
and setting the inside of the processing chamber in a vacuum state, the gas
exhaust unit having a gas exhaust port formed at a lower part of the
processing chamber;

an upper and a lower electrode facing each other while having
therebetween a processing space formed above the gas exhaust port inside
the processing chamber, the lower electrode serving as a mounting table for
mounting thereon the substrate to be processed;

an electric field forming unit for forming an electric field by applying
an electric power between the upper and the lower electrode, the electric
field exciting the processing gas in the processing space to convert same into
a plasma;

a baffle plate interposed between the processing space and the gas
exhaust port such that the plasma is confined in the processing space,
wherein the baffle plate includes a main body having multiple through holes

1 An oral hearing was held on October 21, 2009.
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Application 11/016,997

allowing the processing space and the gas exhaust port to communicate with
each other and a mounting portion for mounting the main body in the
processing chamber; and

a magnetic field forming unit for forming a magnetic field, wherein
the magnetic field includes central magnetic force lines running parallel to a
top surface of the substrate mounted on the mounting table and magnetic
force lines, which pass through the main body of the baffle plate and are
tilted with respect to the central magnetic force lines, and

wherein the main body of the baffle plate is disposed substantially
parallel to the magnetic force lines passing therethrough.

13. A baffle plate for use in a processing chamber of a magnetron
plasma processing apparatus, the baffle plate being interposed between a
processing space and a gas exhaust port of the apparatus, the baffle plate
comprising:

a truncated cone shaped main body tilted substantially parallel to
magnetic force lines of a magnetic field passing therethrough, the main body
having multiple through holes allowing the processing space and the gas
exhaust port to communicate with each other, the through holes being
formed substantially normal to a surface of the main body at which openings
of the through holes are formed;

an outer mounting portion for mounting the main body to the
processing chamber; and

an inner mounting portion for mounting the main body to the
mounting table.

The Examiner relies on the following evidence to establish
unpatentability (Examiner’s Answer (“Ans.”), mailed Nov. 28, 2008, 3):
Walko, II (Walko) US 6,051,100 Apr. 18, 2000
Kubota US 6,190,495 B1 Feb. 20, 2001
Cheng EP 0 272 142 Jun. 22, 1988
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Application 11/016,997

Applicants’ Admitted Prior Art (“AAPA”) – as disclosed in the
“Background of the Invention” section of the Specification

Appellants request review of the following grounds of rejection (Br.
5):
1. claims 1-5 and 19 under 35 U.S.C. § 103(a) as unpatentable
over Kubota in view of Walko;
2. claim 6 under 35 U.S.C. § 103(a) as unpatentable over Kubota
in view of Walko as applied to claim 1, and further in view of AAPA; and
3. claims 13-15 and 20 under 35 U.S.C. § 103(a) as unpatentable
over Kubota in view of Walko and Cheng.
Appellants’ arguments in support of patentability are based on
limitations found in independent claims 1 and 13. Appellants do not present
separate arguments as to any dependent claims.
ISSUE
Have Appellants shown reversible error in the Examiner’s
determination that, based on the teachings of Walko, it would have been a
matter of routine optimization for the ordinary artisan to adjust the tilt of
Kubota’s baffle plate to a position substantially parallel to magnetic force
lines passing through it, as recited in independent claims 1 and 13?
We answer this question in the affirmative.
FINDINGS OF FACT (“FF”)
1. Appellants and the Examiner disagree over whether the applied
prior art discloses or suggests the following claim limitations:
a magnetic field forming unit for forming a magnetic
field, wherein the magnetic field includes central magnetic
force lines running parallel to a top surface of the substrate
mounted on the mounting table and magnetic force lines, which
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Application 11/016,997

pass through the main body of the baffle plate and are tilted
with respect to the central magnetic force lines, and
wherein the main body of the baffle plate is disposed
substantially parallel to the magnetic force lines passing
therethrough.

(claim 1); and “the baffle plate comprising: a truncated cone shaped main
body tilted substantially parallel to magnetic force lines of a magnetic field
passing therethrough” (claim 13).
2. The Examiner concedes that “Kubota et al. does not expressly
teach that the main body of the baffle plate is disposed substantially parallel
to the tilted magnetic force lines passing therethrough.” (Ans. 4 and 8.)
However, the Examiner finds that “Walko teaches that a baffle plate 40 can
be tilted upwards in an outward radial direction, and can be of a truncated
cone shape. (Figure 1).” (Ans. 5 and 8.) The Examiner concludes that
[i]t would have been obvious to one of ordinary skill in the art,
through routine experimentation, to determine the placement of
the baffle plate taught by Kubota et al. as a result-effective
variable as taught by Walko (Column 8, Line 65 - Column 9,
Line 5) to have the baffle plate be tilted upwards in an outward
radial direction, and be of a truncated cone shape, so as to be
disposed substantially parallel to the tilted magnetic force lines
passing therethrough, in order to obtain the predictable result of
optimizing the boundary between where active plasma is
desired and where no active plasma is desired.

(Ans. 5 and 8-9.)
3. Appellants contend that the Examiner erred in determining that
it would have been obvious to optimize the tilt of Kubota’s baffle plate in
view of Walko’s disclosure, because the Examiner did not establish that
Walko recognizes the angle of a baffle plate with respect to a magnetic field
as a result-effective variable. (Br. 7.)
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4. In response, the Examiner asserts that the claimed relationship
between the magnetic force lines and baffle plate would naturally result from
modifying the position of Kubota’s baffle plate so as to optimize the
boundary between where active plasma is and is not desired as taught by
Walko. (Ans. 12.)
5. Figure 1 of Walko illustrates a reactive ion etch chamber in
which a containment structure is tilted upwards in an outward radial
direction, and appears to have a truncated cone shape. (See Fig. 1; Ans. 5
and 9.) Walko describes the containment structure as
a plate made of an electrically conductive material configured
to contain an electromagnetic field within a desired space in the
chamber by attenuating the field generated in the chamber
while maintaining high conductance across the plate. The plate
contains openings having surrounding conductive surfaces
therethrough for permitting gas flow within the chamber.

(Walko, col. 4, ll. 4-10.) Walko teaches that “a containment structure
40 is placed at the desired boundary between where the active plasma
is desired and where no active plasma is desired.” (Col. 8, l. 66-col. 9,
l. 2.) Walko describes angling the walls of the openings in the
containment structure such that “the surfaces [are] oriented in a
direction less than or substantially equal to 90º from the direction of
the electromagnetic field at the opening.” (Col. 4, ll. 12-15.)
According to Walko, [t]his causes the electromagnetic fields to fall off
very rapidly within the openings and become too weak to sustain a
plasma before they reach the other side of the plate.” (Col. 9, ll. 43-
46.)

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PRINCIPLES OF LAW
“[A] reasonable expectation of success, not absolute predictability”
supports a conclusion of obviousness. In re Longi, 759 F.2d 887, 897 (Fed.
Cir. 1985). However,
to have a reasonable expectation of success, one must be
motivated to do more than merely [] vary all parameters or
try each of [the] numerous possible choices until one
possibly arrive[s] at a successful result, where the prior art
gave either no indication of which parameters were critical or
no direction as to which of many possible choices is likely to
be successful.

Pfizer, Inc. v. Apotex, Inc., 480 F.3d 1348, 1365 (Fed. Cir. 2007) (quoting
Medichem, S.A. v. Rolabo, S.L., 437 F.3d 1157, 1165 (Fed. Cir. 2006)
(internal quotations omitted)); cf. In re Antonie, 559 F.2d 618, 620 (CCPA
1977) (explaining that a particular parameter must first be recognized as a
result-effective variable, i.e., a variable which achieves a recognized result,
before the determination of the optimum or workable ranges of said variable
might be characterized as routine experimentation).
ANALYSIS
Appellants have persuasively argued that the Examiner’s findings are
insufficient to establish that one of ordinary skill in the art, upon review of
Walko’s disclosure, would have recognized that optimization of the
boundary between where active plasma is desired and where no active
plasma is desired in Kubota’s reactive ion chamber could be achieved by
adjusting the tilt of the baffle plate to a position substantially parallel to
magnetic force lines passing through it. The Examiner has not directed us
to, nor do we find in Walko, any indication of criticality in the angle at
which the containment structure/baffle plate is positioned in the chamber.
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Rather, as argued by Appellants, Walko’s disclosure is clearly directed to
adjusting the angles of the through holes in the containment structure/baffle
relative the electric field direction. (Br. 7.)
CONCLUSION
Appellants have identified reversible error in the Examiner’s
obviousness determination as to independent claims 1 and 13. Therefore, we
reverse all three grounds of rejection.
REVERSED

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OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA, VA 22314
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