Ex Parte Fischer et al

Board of Patent Appeals and Interferences

Apr 26, 2010

10445146 (B.P.A.I. Apr. 26, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte ANDREAS FISCHER, WILLIAM S. KENNEDY,
PETER LOEWENHARDT, and DAVID TRUSSELL
____________________

Appeal 2009-013927
Application 10/445,146
Technology Center 1700
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Decided: April 26, 2010
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Before MICHAEL P. COLAIANNI, CATHERINE Q. TIMM, and
JEFFREY T. SMITH, Administrative Patent Judges.

TIMM, Administrative Patent Judge.

DECISION ON APPEAL
I. STATEMENT OF CASE
Appellants appeal under 35 U.S.C. § 134 from the Examiner’s
decision to reject claims 1-7, 10, 21, 23-25, and 35-38. We have jurisdiction
under 35 U.S.C. § 6(b).
We REVERSE.
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Appellants’ invention relates to a multi-part upper electrode for a
semiconductor plasma reactor in which a central portion of the electrode is
independently replaceable from an outer peripheral portion of the electrode
(Spec. ¶ [0022]). Claim 1 is illustrative:
1. A multi-part electrode for a plasma reaction
chamber comprising:
an electrode top plate; and
an electrode connected to the top plate, the electrode
including a central silicon element and a plurality of silicon
segments surrounding the central silicon element, the silicon
segments forming a step on a lower surface of the electrode,
wherein the central silicon element is removable from the top
plate independent of the silicon segments; and
sealing ring to prevent gas flow in an annulus between
the central silicon electrode and the silicon segments;
wherein the central silicon element has a maximum
thickness which is less than a maximum thickness of the silicon
segments.
The Examiner relies upon the following evidence:
First Named Inventor Document No. Issue or Pub. Date
Lenz
Foster
Strang
US 5,569,356
US 6,220,202 B1
US 6,806,653 B2
Oct. 29, 1996
Apr. 24, 2001
Oct. 19, 2004
Lilleland
Fischer
Urano1
US 2001/0031557 A1
US 2004/0074609 A1
JP 10-289881 A
Oct. 18, 2001
Apr. 22, 2004
Oct. 27, 1998

1 We refer to the English language Abstract and the computer-prepared
English language translation of Urano made of record in an Office
Communication mailed June 20, 2006.
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The Examiner maintains, and Appellants seek review of, the
following rejections:
1. The rejection of claims 1, 2, 5-7, 10, 21, 23-25, 35, and 36 under
35 U.S.C. § 103(a) as unpatentable over admitted prior art in view of
Urano, Strang, and Lenz;
2. The rejection of claims 3 and 4 under 35 U.S.C. § 103(a) as
unpatentable over admitted prior art in view of Urano, Strang, Lenz,
and Lilleland;
3. The rejection of claims 37 and 382 under 35 U.S.C. § 103(a) as
unpatentable over admitted prior art in view of Urano, Strang, Lenz,
and Foster.
II. DISPOSITIVE ISSUE
The issue raised by the contentions of Appellants and the Examiner is:
Did the Examiner provide a sufficient reason why one of ordinary skill in the
art would have modified electrode 10 of admitted prior art Figure 1 to obtain
the central silicon element and surrounding silicon segments required by
claim 1 based on the teachings of Urano? We answer this question in the
negative.
III. FINDINGS OF FACT
1. The admitted prior art Figure 1 includes an upper electrode 10 with a
step 14 ground into the electrode “to provide etch rate uniformity at the
edge of the chip” and a separate extension electrode 16 which is

2 The Examiner’s rejection is stated as the rejection of claims 36 and 37
(Ans. 3 and 12). However, as pointed out by Appellants, it appears that the
Examiner intended to reject claims 37 and 38 (Br. 17-18; Reply Br. 7). We
consider this misstatement harmless error.
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constructed of a plurality of silicon electrode segments (Spec. ¶¶ [0011]-
[0012]; Figure 1).
2. Urano teaches an assembly which has a central electrode portion 24 and
a peripheral edge portion 25, at least one of which are vertically movable
(Urano, English Language Abstract).
3. Figure 1 of Urano shows the central electrode portion 24 having a
thickness less than the peripheral edge portion 25 (Urano, Figure 1).
4. Urano teaches that the independently adjusted electrodes provide an
expanded field where the plasma is uniform (Urano, ¶ [0020]).
IV. PRINCIPLES OF LAW
Rejections based on § 103(a) must rest on a factual basis with these
facts being interpreted without hindsight reconstruction of the invention
from the prior art. In re Warner, 379 F.2d 1011, 1017 (CCPA 1967).
V. ANALYSIS
In the Examiner’s rejection of claim 1, the Examiner states that:
it would have been obvious to one of ordinary skill in the art at
the time of the invention to modify the extension segments 16
[of admitted prior art Figure 1 from Appellants’ Specification]
to extend to include the step 14 of the Admitted Prior Art so
that the central element has a maximum thickness which is less
than a maximum thickness of the segments as taught by Urano
since it is obvious to make a top electrode separable and the
thickness of the peripheral electrode surface affects the plasma
distribution on the surface of the wafer.
(Ans. 5.)
Appellants contend that the Office has not established that the
proposed modifications of the prior art assembly would have been obvious
to one of ordinary skill in the art because, among other things, the admitted
prior art includes an electrode extension that “is already separated from the
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electrode 10” and that “the APA [admitted prior art] electrode assembly
already includes a portion to affect the plasma distribution at the peripheral
edge of the wafer” (Reply Br. 4 and 5). We agree.
The Examiner has not provided a sufficiently reasonable rationale for
modifying the admitted prior art. The admitted prior art upper electrode was
already separated into a central section 10 and extension segments 16. Thus,
one of ordinary skill in the art would not have needed an alternative
separation between the electrode portions without a further articulated
reason to do so. Likewise, the admitted prior art already included a step 14
to address the uneven distribution of plasma at the edges of a chip. Thus,
one of ordinary skill in the art would not have raised or lowered the
respective electrode sections of the admitted prior art to address the same
problem addressed by step 14.
Accordingly, there is a reversible error in the Examiner’s reasoning
for combining the teachings of Urano and the admitted prior art.
The Examiner applied the teachings of Urano and the admitted prior
art in the same way for each of the independent and dependent claims.
Accordingly, we cannot sustain any of the Examiner’s rejections.
VI. CONCLUSION
On the record before us and for the reasons discussed above, we
cannot sustain the rejections maintained by the Examiner.
VII. DECISION
We reverse the Examiner’s decision.
REVERSED
cam

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