Ex Parte LI et al

Board of Patent Appeals and Interferences

Sep 26, 2007

10164986 (B.P.A.I. Sep. 26, 2007)

The opinion in support of the decision being entered today
is not binding precedent of the Board.

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte CHANG-JUNG LI, WEN-MING CHEN,
KUN-YEN FAN, and WEN-CHI WANG
____________

Appeal 2007-4189
Application 10/164,986
Technology Center 1700
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Decided: September 26, 2007
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Before BRADLEY R. GARRIS, CHUNG K. PAK, and
JEFFREY T. SMITH, Administrative Patent Judges.

SMITH, Administrative Patent Judge.

DECISION ON APPEAL
Statement of the Case
This is an appeal under 35 U.S.C. § 134 from a final rejection of
claims 1-9, 11, and 21-29. We have jurisdiction under 35 U.S.C. § 6.
Appeal 2007-4189
Application 10/164,986

Appellants’ invention relates to a composite shadow ring for use in a
plasma etch chamber that is constructed of an upper ring and a lower ring
assembled together with dowel pins. Claims 1 and 21 are illustrative:
1. A composite shadow ring comprising:
a first ring having a first outside diameter, a planar top surface and a
planar bottom surface parallel to the planar top surface, said planar bottom
surface having at least two blind holes therein;
a second ring having a second outside diameter substantially similar to
said first outside diameter, a planar top surface and a planar bottom surface
parallel to said planar top surface, said planar top surface having at least two
blind holes therein; and
at least two dowel pins connecting said first and second ring together
by frictionally engaging said at least two blind holes in said first ring and
said at least two blind holes in said second ring with said bottom planar
surface of the first ring abutting said top planar surface of the second ring
wherein said at least two dowel pins are each formed of injection molded
plastic.
21. A composite shadow ring comprising:
a first ring having a first outside diameter, a planar top surface and a
planar bottom surface parallel to the planar top surface, said planar bottom
surface having at least two blind holes therein;
a second ring having a second outside diameter substantially similar to
said first outside diameter, a planar top surface and a planar bottom surface
parallel to said planar top surface, said planar top surface having at least two
blind holes therein;
at least two dowel pins connecting said first and second ring together
by frictionally engaging said at least two blind holes in said first ring and
said at least two blind holes in said second ring with said bottom planar
surface of the first ring abutting said top planar surface of the second ring;
and
an insert ring situated inside and abutting an inside peripheral surface
of said first and second ring.
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Appeal 2007-4189
Application 10/164,986

The Examiner relies on the following references in rejecting the
appealed subject matter:
Harvey US 5,887,733 Mar. 30, 1999
Tolles US 6,036,587 Mar. 14, 2000
Clark US 6,088,985 Jul. 18, 2000
Flach US 6,537,625 B2 Mar. 25, 2003
Claims 1-9, 11, and 21-29 stand rejected under 35 U.S.C. § 103(a) as
follows:
I. Claims 1-7, and 11 stand rejected over Appellants' admitted prior art
(AAPA) in view of Tolles, Flach, and Clark.
II. Claims 8-9 stand rejected over AAPA, Tolles, Flach, Clark, and Harvey.
III. Claims 21-25 stand rejected over AAPA and Tolles.
IV. Claims 26-27 stand rejected over AAPA, Tolles, and Harvey.
V. Claims 28 and 29 stand rejected over AAPA in view of Tolles, Flach,
and Clark.
We REVERSE the rejections of claims 1-9 and 11. However, we
AFFIRM the rejections of 21-29.
Claims 1-9 and 111
Claim 1 specifies that dowel pins connecting said first and second ring
together are formed of injection molded plastic. The Examiner
acknowledges that AAPA and Tolles do not describe dowels formed from
injection molded plastic (Answer 4). The Examiner asserts that Flach and
Clark describe fiber reinforced plastic dowels. The Examiner concluded that
it would have been obvious to use fiber reinforced plastic dowels for their

1 We will limit our discussion to independent claim 1.
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Appeal 2007-4189
Application 10/164,986

strengths and good thermal insulation properties in the composite shadow
rings of the AAPA (Answer 4).
Appellants contend that there is no motivation to combine Tolles,
Flach, and Clark with the AAPA because there is no correlation between the
semiconductor fabrication equipment art and the construction industry art
(Br. 7-8). Accordingly, we determine that the issue presented is as follows:
Has the Examiner made sufficient factual findings such that it is reasonable
to conclude that one of ordinary skill in the art would have been led to
combine the teachings of the references in the manner claimed within the
meaning of 35 U.S.C. § 103? We answer this question in the negative. The
issue turns on whether the Flach and Clark references are analogous to the
semiconductor fabrication equipment art.
The Specification describes the AAPA as following:
In still another improved design of composite shadow ring,
shown in Figures 2 and 2A, the composite shadow ring 50,
shown in a cross-sectional view in Figure 2 and in a plane view
in Figure 2A, is constructed by an upper ring 54 and a lower ring
56. The advantage of this configuration of two flat, concentric
rings assembled together by locating pins 60 is that only the
upper ring 54 is exposed to the plasma ions in the etch chamber
and therefore, only the upper ring 54 is subjected to the etching
effect of the plasma. As a result, only the upper ring 54 needs to
be replaced after repeated usage of the composite shadow ring
50. For instance, a commercially available composite shadow
ring 50 is constructed by an upper ring 54 fabricated of silicon
and a lower ring 56 fabricated of silicon dioxide.
While the composite shadow ring 50 shown in Figure 2
presents the benefit that only the upper ring 54 is subjected to
plasma corrosion and therefore only the upper ring 54 needs to
be replaced, it presents a processing problem in that the lower
ring 56 is difficult to clean during a preventive maintenance
procedure. The locating pins 60 which are formed of quartz
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Appeal 2007-4189
Application 10/164,986

material integrally with or inserted into the lower ring 56 are
frequently subjected to breakage during the cleaning procedure.
When one or more of the locating pins 60 break off from the
lower ring 56, the lower ring can no longer engage the upper
ring 54 and must be scrapped. Broken locating pins 60
therefore leads to the complete replacement of the composite
shadow ring 50.
(Specification 9-10).
Tolles discloses a chemical mechanical polishing system using dowel
pins to abut two surfaces together. Tolles does not describe composite
shadow rings or the material from which the dowels are made.
Flach is directed to concentric finger joints for end joining two
segments of timber (Flach, col. 1, ll. 16-18). Flach discloses that fiber
reinforced plastic dowels can be used to join aligned cavities (Flach, col. 1,
ll. 43-45; col. 6, ll. 49-52).
Clark is directed to the field of precast concrete insulated sandwich
panels (Clark, col. 1, ll. 10-15). Clark discloses that fiber reinforced plastic
dowels can be used to replace steel (Clark, col. 1, ll. 56-63).
Harvey is directed to a modular tower tooling system that comprises
two or more bases that have been joined together (Harvey, col. 1, ll. 4-10).
Harvey discloses dual diameter dowels (See Fig. 6).
The Federal Circuit has delineated two criteria for indicating whether
prior art references are analogous: (1) whether the art is from the same field
of endeavor, regardless of the problem addressed, and (2) if the art is not
within the same field endeavor, whether it is reasonably pertinent to the
particular problem to be solved. In re Clay, 966 F.2d 656, 658-59,
23 USPQ2d 1058, 1060 (Fed. Cir. 1992); In re Deminski, 796 F.2d 436, 442,
230 USPQ 313, 315 (Fed. Cir. 1986); In re Wood, 599 F.2d 1032, 1036,
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Appeal 2007-4189
Application 10/164,986

202 USPQ 171, 174 (CCPA 1979). In the present case, the claimed
invention and the invention of the AAPA are directed to semiconductor etch
chamber equipment that employs shadow masks. Flach and Clark are
directed to the construction industry. Thus, Flach and Clark are not in the
same field of endeavor as the claimed invention and the AAPA.
Thus, we must now determine whether Flach and Clark are reasonably
pertinent to the particular problem to be solved. The issue turns on whether
Flach and Clark describe materials that would be suitable for use in
semiconductor etch chamber equipment.
The Specification describes the semiconductor fabrication equipment
that utilizes a shadow ring as follows:
In an etch chamber equipped with a plasma generating
device and an E-chuck, a shadow ring may be utilized as a seal
around the peripheral edge of the wafer. The shadow ring, also
known as a focus ring, is utilized for achieving a more uniform
plasma distribution over the entire surface of the wafer and for
restricting the distribution of the plasma cloud to only the wafer
surface area. The uniform distribution function may be further
enhanced by a RF bias voltage applied on the wafer during a
plasma etching process. Another function served by the
shadow ring is sealing at the wafer level the upper compartment
of the etch chamber which contains the plasma from the lower
compartment of the etch chamber which contains various
mechanical components for controlling the E-chuck. This is
important since it prevents the plasma from attacking the
hardware components contained in the lower compartment of
the etch chamber. In order to survive high temperature and
hostile environments, a shadow ring is frequently constructed of
a ceramic material such as quartz.
(Specification 3-4).

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Appeal 2007-4189
Application 10/164,986

Thus, materials that are employed in semiconductor etch chamber
equipment must be capable of surviving high temperature and hostile
environments. The Examiner has not identified, nor have we discovered, the
portions of Flach and Clark that indicate the dowel material described
therein would have been capable of withstanding the high temperature and
hostile environment employed in semiconductor etch chamber equipment.
Thus, we determine that Flach and Clark are not reasonably pertinent to the
particular problem to be solved.
For these reasons, and those presented by Appellants in the Brief, we
determine that there is an insufficient basis to combine the teachings of the
cited prior art. Therefore, we reverse the rejection of claims 1-9 and 11.
Claims 21-292
The subject matter of claim 21 is a different matter. Claim 21 does
not specify the materials from which the dowels are made. Appellants
contend that the structure of independent claim 21 is not described by the
AAPA. Specifically, Appellants contend that Figure 2A discloses only blind
holes formed in the first ring, and not in the second ring, and Tolles does not
describe blind holes in a first and second ring (Br. 10).
Appellants’ arguments are not persuasive because AAPA discloses
that the dowels can be inserted into the second ring. Although not depicted
in Figure 2A, the AAPA discloses “[t]he locating pins 60 which are formed
of quartz material integrally with or inserted into the lower ring 56”
(Specification 10, emphasis added). Thus, it can be reasonably inferred that

2 Appellants have not presented separate arguments for claims 22-29. The
arguments presented in the Brief are the same as the arguments presented for
claim 21 (See Br. 10-12). Thus, we will limit our discussion to claim 21.
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Appeal 2007-4189
Application 10/164,986

the lower ring taught by AAPA comprises blind holes. In other words, we
find that AAPA either teaches or would have suggested “at least two dowel
pins connecting said first and second ring together by frictionally engaging
said at least two blind holes in said first ring and said at least two blind holes
in said second ring” as required by claim 21.
Accordingly, we affirm the Examiner's rejections of claims 21-29.
ORDER
The Examiner's decision rejecting claims 1-9 and 11 is reversed. The
Examiner's decision rejecting claims 21-29 is affirmed. The decision of the
Examiner is affirmed-in-part.
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-IN-PART

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