Naoki Matsumoto et al.

Patent Trials and Appeals Board

Nov 7, 2019

13542068 - (D) (P.T.A.B. Nov. 7, 2019)

UNITED STATES PATENT AND TRADEMARK OFFICE
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.
13/542,068 07/05/2012 Naoki MATSUMOTO BPL0181US 5572
23413 7590 11/07/2019
CANTOR COLBURN LLP
20 Church Street
22nd Floor
Hartford, CT 06103
EXAMINER
DHINGRA, RAKESH KUMAR
ART UNIT PAPER NUMBER
1716
NOTIFICATION DATE DELIVERY MODE
11/07/2019 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):
usptopatentmail@cantorcolburn.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte NAOKI MATSUMOTO and YASUHIRO OTSUKA
____________

Appeal 2018-004590
Application 13/542,068
Technology Center 1700
____________

Before MARK NAGUMO, KAREN M. HASTINGS, and
DONNA M. PRAISS, Administrative Patent Judges.

PRAISS, Administrative Patent Judge.

DECISION ON APPEAL
Appellant1 appeals under 35 U.S.C. § 134(a) from the Examiner’s
decision2 finally rejecting claims 1 and 3. We have jurisdiction under
35 U.S.C. § 6(b).
We AFFIRM.

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. Tokyo Electron Limited is identified as the real party in
interest. Appeal Brief, filed July 13, 2017 (“Appeal Br.”) 3.
2 Final Office Action, dated March 30, 2017 (“Final Act.”).
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STATEMENT OF THE CASE
Background
The subject matter on appeal relates to “a plasma processing apparatus
capable of preventing generation of an extraneous material.” Substitute
Specification, filed July 10, 2012 (“Spec.”) 2:5–6. According to the
Specification, an object to be processed is held by a holding member as a
focus ring surrounds an outer circumferential wall surface of the holding
member such that a gap equal to or less than 350 µm is defined between the
inner circumference of the focus ring and the outer circumferential wall
surface of the holding member. Id. at 2:7–15, 2:27–31. The Specification
discloses an equation for computing a Debye length, defined as “an order of
a length blocking the electric field.” Id. at 12:24–13:5. Under an electron
density of 6x109 cm-3 and an electron temperature of 1.5eV, the range of less
than 350 µm for the gap is correlated to less than three times the Debye
length. Id. at 13:13–16. The Specification explains that “an electrical
neutrality of plasma is not obtained in a space smaller than the Debye length
λD.” Id. at 13:5–6. In other words, a plasma cannot exist in such a small gap,
id. at 13:6–9, and if a gap is “equal to or less than two or three times the
Debye length λD, plasma is prevented from entering the gap.” Id. at 13:10–
11.
In addition to the structure of a particular gap size preventing plasma
from entering the gap, thereby preventing generation of minute particles, the
Specification discloses the gap being covered by the object to be processed
as also preventing plasma from entering the gap and thereby preventing
generation of minute particles. Id. at 2:27–31, 3:8–12.
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Of the appealed claims, claim 1 is independent. Claim 1 is
representative of the subject matter on appeal, and reproduced below
(disputed limitations italicized):
1. A plasma processing apparatus comprising:
a processing container which defines a processing space;
a gas supplying unit which supplies a processing gas to the
processing space;
an introducing unit which introduces energy for generating
plasma of the processing gas;
a holding member disposed in the processing space, having a
top surface on which an object to be processed can be held, and
comprising an electrode such that the object can be held by
using electrostatic force, the holding member having an outer
circumferential wall surface,
wherein the outer circumferential wall surface has a portion
which is substantially straight and a remainder is an
approximately circular shape when viewed from a top; and
a focus ring disposed around the holding member and having an
inner wall surface facing the outer circumferential wall surface
of the holding member, wherein, when viewed from a top, the
inner wall surface of the focus ring has substantially a same
shape as the outer circumferential wall surface of the holding
member, and the straight portion of the outer circumferential
wall surface and a straight portion of the inner wall surface is
parallel to each other,
wherein a first gap is defined between the straight portion of the
outer circumferential wall surface and the straight portion of the
inner wall surface, a second gap is defined between the
remainder of the outer circumferential wall surface and a
remainder of the inner wall surface, and each of the first gap
and the second gap has a size equal to or less than three times
of debye length (λD) presented by an equation below,

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wherein Te represents an electronic temperature and n0
represents an electronic density,
wherein the focus ring comprises an inner top surface
comprising an inner circumference, and an outer top surface
around the inner top surface,
wherein the inner top surface has a level substantially the same
as the top surface of the holding member such that the first gap,
the second gap and a portion of the inner top surface are
covered by the object without a vertical gap between the
portion of the inner top surface and the object for prevention of
accumulation or adherence of minute particles, and
wherein the outer top surface has a level higher than the top
surface of the holding member.
Appeal Br. 23 (Claims Appendix).

The References
Sato US 2011/0116207 A1 May 19, 2011
Huang US 6,117,349 Sept. 12, 2000
Morikage US 2003/0066484 A1 Apr. 10, 2003

The Rejection
The Examiner maintains the following rejection on appeal: Claims 1
and 3 are rejected under 35 U.S.C § 103(a) over Sato, Huang, and Morikage.
Final Act. 3–10.
OPINION
After having considered the evidence presented in this Appeal and
each of Appellant’s contentions, we are not persuaded the Examiner erred
harmfully.
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In rejecting claim 1, the Examiner finds that Sato teaches the elements
of claim 1 except Sato does not teach that the gap defined between the outer
circumferential wall surface and the inner wall surface of the focus ring has
a substantially straight portion with the remainder approximately circular
shape. Final Act. 3–5. The Examiner determines that it would have been
obvious to optimize the gaps between the holding member and the focus ring
to be equal to or less than a few Debye lengths as well as the vertical gap
between the object and the inner top surface of the focus ring in view of
Sato’s teaching that (1) gap C between the outer circumferential wall surface
and the inner wall surface of the focus ring has a size of 0.05mm to 0.4 mm
to prevent plasma from entering the gap and to prevent damage due to edge
contact between the holding member and the focus ring and (2) gap B
between the object W and inner top surface of the focus ring is optimized
(equal to or smaller than 0.4 mm) to prevent plasma from reaching the
surface of the holding member and arcing, and particle generation. Id. at 4
(citing Sato ¶¶ 59, 61: Fig. 2). The Examiner also finds that it would have
been obvious to optimize Sato’s gaps to be equal to or less than three times
the Debye length as required by claim 1 in view of Huang’s teaching gaps in
a process chamber that are larger than a few Debye lengths may either cause
a gas breakdown, or the plasma may be extracted into the sufficiently large
gaps. Id. at 6 (citing Huang 2:13–58).
The Examiner finds that although Sato in view of Huang discloses
optimizing gaps B and C, the combination does not explicitly teach the first
gap, the second gap, and a portion of the inner top surface are covered by the
object. Id. at 7. The Examiner determines it would have been obvious to
provide a holding member with outer circumferential wall surface having a
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substantially straight portion and the remainder approximately circular shape
in view of Morikage’s teaching that it is a known structure of a holding
member and surrounding focus ring in a plasma process apparatus. Id. at 8–9
(citing Morikage Figs. 4–6).
Appellant argues the rejection of claim 1 and points out that claim 3
depends from claim 1. Appeal Br. 21. Accordingly, claim 3 stands or falls
with claim 1. 37 C.F.R. § 41.37(c)(1)(iv).
Appellant asserts that the Examiner erred harmfully in combining the
teachings of Huang with Sato because Huang discloses an ideal or
theoretical solution of limiting gaps to less than several Debye lengths that is
not practically possible to maintain. Appeal Br. 13–14. Appellant contends
that because Huang recognizes it is not practically possible to main the
interval between the electrostatic chuck and the shadow ring as several
Debye lengths, Huang alternatively teaches contacting the end portion of the
wafer with the inner end portion of the shadow ring to isolate the upper and
lower portions of the chamber. Id. at 13. Appellant also contends that the
Examiner erred in combining Morikage with Sato or Huang because there is
no motivation to do so since the flat portions of the holding member and the
focus ring have no intended purpose to block plasma infiltration. Id. at 15.
According to Appellant, Morikage does not block plasma infiltration
because Morikage’s wafer does not touch a focus ring surface. Id. Appellant
also argues that the effect of the claimed invention is accomplished with the
simultaneous combination of claimed features (1) no vertical gap between
the object and the focus ring top surface, (2) a gap of three times the Debye
length or less between the holding member and the focus ring, and (3) a
straight portion in the holding member and the focus ring. Id. at 10, 15.
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In response to Appellant’s arguments, the Examiner finds that it is
Sato that teaches it is desirable for the gap between the end portion of the
wafer and the inner end portion of the focus ring to be equal to or smaller
than 0.4 mm, which includes no gap. Ans. 3 (citing Sato ¶ 58, Fig. 2). Sato’s
Figure 2 is reproduced below.

Figure 2 is a partial cross-sectional view of a substrate mounting table
depicting electrostatic chuck 23, focus ring 25, wafer W, and vertical gap B.
Sato ¶¶ 32, 57, 58.
The Examiner points out that due to realistic issues, namely, the
inevitable non-uniformity of the wafer’s bottom surface and the top surface,
which Appellant acknowledges exist, plasma is not perfectly blocked from
entering near the gaps. Ans. at 3–4 (citing Appeal Br. 12 “claimed feature 1
does not perfectly block the plasma from entering near gaps”). Appellant’s
annotated Figure 4 is shown below.
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Annotated Figure 4 is said to show why Appellant’s features 1 and 2 are
both required to be present together and not alone. Appeal Br. 12. The
Examiner finds that Sato teaches a value for gap “C” of 0.5 mm to 0.4 mm
to prevent plasma from entering gaps between the focus ring and the
electrostatic chuck. Id. at 3 (citing Sato 56–59, Fig. 2). The Examiner finds
that Sato’s gap value (50–400μm regardless of electron temperature and
electron density) overlaps Appellant’s example Debye length value of 117
micron times three (117 μm x3=351 μm). Id. at 6–7 (citing Sato ¶¶ 56–59;
Spec. 13:5). The Examiner also finds that Huang discloses calculating
Debye length (the relationship between Debye length, electron temperature,
and electron density) for limiting gaps (to less than several Debye lengths)
between the electrostatic chuck and a shadow ring. Id. at 3, 6–7 (citing
Huang 2:55–60). Regarding Morikage, the Examiner finds that Morikage
discloses a known structure of a holding member and surrounding focus ring
in a plasma processing apparatus that is used to obtain a proper fit of the
focus ring. Id. at 5.
The preponderance of the evidence cited in this Appeal record
supports the Examiner’s rejection of claim 1. In the Reply Brief, Appellant
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asserts that the Examiner relies upon Huang rather than Sato for the claimed
configurations of (1) the object covering the gap between the inner top
surface of the focus ring and the holding member and (2) the gap between
the holding member and the focus ring being three times Debye length or
less. Reply Br. 4. However, the Examiner relies on Sato’s disclosure for
disclosing the object covering the gap as well as for disclosing a gap range
encompassing the claimed range. Ans. 3. Appellant does not dispute the
Examiner’s finding that three times the Debye length disclosed in the
Specification is encompassed by Sato’s disclosed range of 0.05 mm to 0.4
mm. Sato ¶ 59; Fig. 2; gap C.
Appellant also does not dispute Huang discloses gaps surrounding the
holder should not exceed several Debye lengths. Huang 2:13–58. Instead,
Appellant argues that the gap length disclosed by Huang is not achieveable
in practice. Reply Br. 4–5; Appeal Br. 13–14. Specifically, Appellant
contends Huang’s statement, “ideal equipment conditions cannot be
achieved in a manufacturing environment” means that the reference
“recognizes that the minute adjustment . . . using the debye length is actually
NOT possible” and instead only covers the gap with the object. Reply Br. 4–
5.
The difficulty with Appellant’s argument is that in a determination of
obviousness, a reference may be relied upon for all that it would have
reasonably suggested to one having ordinary skill in the art. Merck & Co. v.
Biocraft Labs., 874 F.2d 804, 807 (Fed. Cir. 1989) (“That the [prior art]
patent discloses a multitude of effective combinations does not render any
particular formulation less obvious.”). Moreover, “a reference is not limited
to the disclosure of specific working examples.” In re Mills, 470 F.2d 649,
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651 (CCPA 1972) (citation omitted). Here, Huang describes the “ideal
situation” as one in which “plasma can be prevented from being generated in
the gaps or being extracted into the gaps,” which Appellant likewise
acknowledges is an ideal situation and not reality. Appeal Br. 12. Rather
than stating, that a gap size measured in Debye lengths cannot be achieved
in the apparatus as Appellant suggests, Huang states that “a quartz shadow
ring would only survive about one preventive maintenance cycle or about
2,000 wafers.” Huang 2:65–3:1. That is, in a manufacturing environment,
plasma is not completely prevented from being generated and affecting the
ring. Regarding both features of gap size and object covering the gap being
present in an apparatus, the Examiner relies on Sato for a processing
apparatus configuration that has both the object covering the gap as well as a
gap range that encompasses three Debye lengths or less. Ans. 3. The
Examiner’s findings are supported by the record. Sato ¶¶ 56–59; Fig. 2.
Finally, Appellant’s assertion that the Examiner’s modification of
Sato with the teachings of Morikage lacks a reason for combining and is
based on improper hindsight (Reply Br. 11; Appeal Br. 15) is not persuasive
of harmful error because the Examiner has provided a reason for replacing
Sato’s structure with Morikage’s holding member and focus ring having flat
portions. The Examiner finds not only that Morikage discloses a known
holding member and surrounding focus ring structure for use in a plasma
processing apparatus, but also that the flat portion of the structure allows for
proper fit of the focus ring. Final Act. 9; Ans. 5. Thus the Examiner has
provided “‘some articulated reasoning with some rational underpinning to
support the legal conclusion of obviousness’” over the combination of prior
art references. KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007)
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(quoting In re Kahn, 441 F.3d at 977, 988 (Fed. Cir. 2006)). Appellant does
not adequately rebut the Examiner’s findings. Appellant’s assertion that
Morikage’s flat portion configuration is not for the purpose of blocking
plasma filtration (Appeal Br. 15) does not negate the Examiner’s finding that
it is a known configuration for a holding member and surrounding focus ring
in a plasma processing apparatus. “‘The combination of familiar elements
according to known methods is likely to be obvious when it does no more
than yield predictable results.’” Leapfrog Enters., Inc. v. Fisher-Price, Inc.,
485 F.3d 1157, 1161 (Fed. Cir. 2007) (quoting KSR, 550 U.S. at 416). Nor
does Appellant’s argument address the Examiner’s finding that the flat
portion configuration taught by Morikage serves the purpose of obtaining
proper fit of the focus ring. “One of the ways in which a patent’s subject
matter can be proved obvious is by noting that there existed at the time of
invention a known problem for which there was an obvious solution
encompassed by the patent’s claims.” KSR, 550 U.S. at 419–20. The reason
for providing a flat portion to the holder member and surrounding focus ring
need not be for the same purpose as the inventors as Appellant argues. See In
re Kemps, 97 F.3d 1427, 1430 (Fed. Cir. 1996) (Archer) ("Although the
motivation to combine here differs from that of the applicant, the motivation
in the prior art to combine the references does not have to be identical to that
of the applicant to establish obviousness.")
Accordingly, we affirm the Examiner’s rejection of claims 1 and 3
under § 103(a) over Sato, Huang, and Morikage.
For these reasons and those the Examiner provides, we uphold the
Examiner’s rejections of claims 1 and 3 under 35 U.S.C. § 103 as obvious
over the cited prior art references.
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CONCLUSION
The Examiner’s rejection of claims 1 and 3 under 35 U.S.C. § 103(a)
is affirmed.

In summary:
Claim(s)
Rejected
35 U.S.C.
§ References/Basis Affirmed Reversed
1, 3 103(a) Sato, Huang, Morikage 1, 3

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

AFFIRMED