Ex Parte Gelatos et al

Board of Patent Appeals and Interferences

Jun 30, 2009

10792054 (B.P.A.I. Jun. 30, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte AVGERINOS V. GELATOS, OLKAN CUVALCI, TONG
ZHANG, and CHEN-AN CHEN
____________

Appeal 2008-003319
Application 10/792,054
Technology Center 3700
____________

Decided:1 June 30, 2009
____________

Before JENNIFER D. BAHR, LINDA E. HORNER, and STEVEN D.A.
McCARTHY, Administrative Patent Judges.

BAHR, Administrative Patent Judge.

DECISION ON APPEAL

1 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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STATEMENT OF THE CASE
Avgerinos V. Gelatos et al. (Appellants) appeal under 35 U.S.C. § 134
from the Examiner's decision rejecting claims 1-24. Claims 25-31 have been
withdrawn. We have jurisdiction over this appeal under 35 U.S.C. § 6
(2002).
The Invention
Appellants' claimed invention is directed to a support for substrates in
a substrate processing chamber. For example, the substrate may be a
semiconductor fabricated in a semiconductor processing chamber using a
chemical vapor deposition (CVD) process. Specification 2:8-11. Substrate
support 20 is made of a ceramic block 28 with a top surface 22 having a
receiving pocket 24 that holds substrate 21 during processing. Specification
6:5-10. Because the various surfaces of ceramic block 28 are subject to
corrosion from gases present during processing (Specification 6:22-25), a
ceramic coating 40 is placed over block 28; coating 40 being made of a
different ceramic material than block 28 (Specification 7:1-5). The ceramic
coating 40 can be, for example, silicon nitride (Si3N4), or an amorphous Si-
N-H-O compound. Specification 9:1-2, 12-16.
Claim 1, reproduced below, is illustrative of the claimed invention.
1. A substrate support for a substrate processing
chamber, the substrate support comprising:
(a) a ceramic block having a substrate
receiving pocket that is sized to receive a substrate
therein, a peripheral ledge extending about the
substrate receiving pocket, and side surfaces;
(b) a ceramic coating covering the substrate
pocket and peripheral ledge of the ceramic block,
the ceramic coating comprising an amorphous Si-
H-N-O compound;
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(c) a resistance heater in the ceramic block;
and
(d) heater leads extending out of the ceramic
block to conduct electrical power to the resistance
heater.

The Rejections
The Examiner relies upon the following as evidence of
unpatentability:
Berkman US 4,090,851 May 23, 1978
Ishii US 5,851,298 Dec. 22, 1998
Chang US 5,916,370 Jun. 29, 1999
Hwang US 6,009,831 Jan. 4, 2000
Brown US 6,046,758 Apr. 4, 2000
Tachikawa US 6,376,808 B2 Apr. 23, 2002
Chen US 6,423,949 B1 Jul. 23, 2002
Burkhart US 6,469,283 B1 Oct. 22, 2002
Todd US 6,630,413 B2 Oct. 7, 2003

Appellants seek review of the Examiner's rejections under 35 U.S.C.
§ 103(a) of claims 1-5, 7, 8, 11-15, and 17 as unpatentable over Chen in
view of Chang or Berkman, and either Brown or Todd; claims 6, 9, and 16
as unpatentable over Chen in view of Chang or Berkman, Brown or Todd,
and Burkhart or Tachikawa; and claims 10 and 18-24 as unpatentable over
Chen in view of Chang or Berkman, Brown or Todd, and Ishii or Hwang2.

SUMMARY OF DECISION

2 The Examiner relies on alternative references in making these rejections.
However, we will focus our attention on Chen, Chang, and Todd in
reviewing these rejections.
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We AFFIRM.

ISSUE
In rejecting claims 1-5, 7, 8, 11-15, and 17, the Examiner concluded,
in relevant part, that it would have been obvious to take a ceramic block with
a resistive heater that holds substrates in a substrate processing chamber, as
described in Chen, and to coat the ceramic block with a protective barrier, as
described in Chang, the coating being a particular amorphous Si-H-N-O
compound, as described in Todd. Ans. 3-4.
Appellants argue that the subject matter of claims 1-5, 7, 8, 11-15, and
17 is not obvious in view of Chen, Chang, and Todd. Appellants first argue
that Chen, Chang, and Todd do not render obvious the subject matter of
claim 1. App. Br. 8-11. Specifically, Appellants argue that Chen does not
provide motivation for providing a protective coating for its ceramic block
(App. Br. 8); that Chang teaches away from using an amorphous Si-H-N-O
coating and does not disclose a resistance heater (App. Br. 9); and that Todd
does not provide motivation to apply its amorphous Si-H-N-O coating to the
ceramic block in Chen (App. Br. 10-11). Appellants do not present any
separate arguments for claims 2-5, 7, and 8. Appellants separately state that
Chen, Chang, and Todd do not render obvious the subject matter of claims
11-15 and 17, but rely on the same arguments as provided for claim 1 above.
App. Br. 11-13. Therefore, claims 2-5, 7, 8, 11-15, and 17 stand or fall with
claim 1. 37 C.F.R. § 41.37(c)(1)(vii).
Next, Appellants argue that the subject matter of claims 6, 9, and 16 is
not obvious in view of Chen, Chang, Todd, and Burkhart or Tachikawa.
However, Appellants' arguments are the same arguments as provided for
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claim 1 above, with the further assertion that Burkhart and Tachikawa do not
cure the alleged deficiencies of Chen, Chang, and Todd. App. Br. 13-15.
Finally, Appellants argue that the subject matter of claims 10 and 18-
24 is not obvious in view of Chen, Chang, Todd, and Ishii or Hwang.
However, Appellants' arguments are the same arguments as provided for
claim 1 above, with the further assertion that Ishii and Hwang do not cure
the alleged deficiencies of Chen, Chang, and Todd. App. Br. 15-19.
The dispositive issue presented in this appeal is whether Appellants
have demonstrated that the Examiner erred in rejecting claim 1 (and by
dependency, claims 2-24) as unpatentable under 35 U.S.C. § 103(a) by
concluding that Chen, Chang, and Todd, in combination, render obvious the
subject matter of claim 1 as a whole. In particular, the issue is whether the
Examiner has provided reasoning with rational underpinning for coating the
ceramic block described in Chen with a protective coating, as described in
Chang, the protective coating being Si-H-N-O, as described in Todd.

FACTS PERTINENT TO THE ISSUES
(FINDINGS-OF-FACT (FF))
FF1 Chen describes a support for a substrate in a chemical vapor
deposition (CVD) apparatus. Col. 5, ll. 57-63. A ceramic block
(susceptor 155) holds a substrate inside CVD chamber 145, and heats
the substrate with a plurality of resistance heaters 250 and 260 located
inside the ceramic block 155. Col. 6, ll. 26-29, 32-36, col. 7, ll. 48-50,
col. 8, ll. 34-39, fig. 1.
FF2 The Examiner found that Chen does not describe a ceramic coating
for the ceramic block 155. Ans. 3.
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FF3 Chang describes a diamond film 150 used to protect a ceramic block
(susceptor 144) from etchants within a semiconductor processing
chamber 102. Col. 2, ll. 46-52, col. 3, ll. 8-12.
FF4 The diamond film 150 described in Chang is substantially inert to
most etchants (col. 3, ll. 8-12), thereby protecting the underlying
ceramic block 144 from the corrosion caused by the etchants that are
used to clean the processing chamber 102 (col. 1, ll. 36-56).
FF5 Chang does not describe that the diamond film 150 is made of silicon
nitride or an amorphous Si-H-N-O compound.
FF6 Todd describes an amorphous silicon nitride compound that is useful
for preventing oxidation and diffusion, as well as useful as a hardmask
in etch process steps. Col. 12, ll. 34-43. Because etching is a process
in which areas of a substrate are selectively removed via corrosion,
the areas of the substrate that are not to be removed (corroded) must
be protected by a material resistant to corrosion from exposure to such
etchant, commonly known in the art as a mask or hardmask.
FF7 The Examiner found that Todd describes an amorphous silicon nitride
compound preferably made of (by approximate wt%): 40-99.5% Si,
0.25-40% N, 0-49.9% O, and <=20% H. Ans. 3-4, see also Todd,
table 1, and col. 4, ll. 39-43.
FF8 Chang describes silicon nitride to be a problem in reactor chambers.
When used in a high temperature nitride process (e.g. CVD), the
silicon nitride is deposited on the wall of the chamber in addition to its
intended target, such that the deposits can eventually build up and
flake off, contaminating the chamber. Col. 1, ll. 34-41.
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FF9 Todd describes the term "silicon nitride" as not a particular chemical
composition, but rather a general term indicating only that a particular
compound contains at least silicon and nitrogen. Col. 4, ll. 11-27. As
such "silicon nitride" refers to a broad array of different chemical
compositions.
FF10 The particular chemical composition of a "silicon nitride" compound
is adjustable to provide suitable resistance to the various corrosive
gases in a semiconductor manufacturing environment. Specification
9:14-16.

PRINCIPLES OF LAW
In obviousness determinations, all of the features of the secondary
reference need not be bodily incorporated into the primary reference. See In
re Keller, 642 F.2d 413, 425 (CCPA 1981). Moreover, the artisan is not
compelled to blindly follow the teaching of one prior art reference over the
other without the exercise of independent judgment. See Lear Siegler, Inc.
v. Aeroquip Corp., 733 F.2d 881, 889 (Fed. Cir. 1984).
While the requirement for a teaching, suggestion, or motivation (the
TSM test) to combine known elements in order to show that the combination
would have been obvious may be "a helpful insight," it cannot be used as a
rigid and mandatory formula. KSR Int’l. Co. v. Teleflex Inc., 550 U.S. 398,
418-19 (2007).
Rejections on obviousness grounds must be supported by "some
articulated reasoning with some rational underpinning" to combine the
known elements in the manner required in the claim at issue. Id. at 418.
However, "the analysis need not seek out precise teachings directed to the
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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." Id.
"[I]f a technique has been used to improve one device, and a person of
ordinary skill in the art would recognize that it would improve similar
devices in the same way, using the technique is obvious unless its actual
application is beyond his or her skill." Id. at 417.
The selection of a known material based upon its suitability for the
intended use is a design consideration within the skill of the art. In re
Leshin, 277 F.2d 197, 199 (CCPA 1960).
When there is a design need or market pressure to
solve a problem and there are a finite number of
identified, predictable solutions, a person of
ordinary skill has good reason to pursue the known
options within his or her technical grasp. If this
leads to the anticipated success, it is likely the
product not of innovation but of ordinary skill and
common sense. In that instance the fact that a
combination was obvious to try might show that it
was obvious under § 103.
KSR, 550 U.S. at 421.

ANALYSIS
The Examiner found that Chen describes each element of claim 1 (see
FF1), except for the amorphous Si-H-N-O compound used as a ceramic
coating for the ceramic support block (FF2). Ans. 3. Next, the Examiner
found that Chang describes the use of a protective coating for a ceramic
block (see FF3, FF4), but ostensibly not an amorphous Si-H-N-O compound
(see FF5). Ans. 3. However, the Examiner found that Todd describes the
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use of an amorphous Si-H-N-O compound with desirable protective
properties. Ans. 3-4; FF7, see FF6. Therefore, the Examiner concluded that
it would have been obvious to coat the ceramic block in Chen with a
protective coating, as described in Chang, the coating being a corrosion-
resistant compound, as described in Todd, to provide a mechanically and
chemically strong protective coating for the ceramic block. Ans. 4.
Appellants' first argument, that Chen does not provide motivation for
coating the ceramic block (App. Br. 8), is not found persuasive. The
Examiner need not establish motivation in order to demonstrate obviousness.
KSR, 550 U.S. at 418-19. In this case, the Examiner found in Chang, not
Chen, the rationale for using a protective coating on the block in Chen. See
Ans. 3-4.
Appellants' second argument, that Chang teaches away from using an
amorphous Si-H-N-O coating (App. Br. 9), is not found persuasive. Chang
does not teach away from using the amorphous Si-H-N-O coating. The
record indicates no passage in Chang that criticizes, discredits, or otherwise
discourages the use of an amorphous Si-H-N-O. See In re Fulton, 391 F.3d
1195, 1201 (Fed. Cir. 2004) ("[M]ere disclosure of alternative designs does
not teach away.").
Furthermore, while Chang does describe problems with silicon nitride
flaking in a processing chamber, Chang is talking about flakes forming from
the use of silicon nitride in a deposition context (such as CVD), not in the
present prophylactic context. See FF8. As such, Chang says nothing as to
the particular suitability of silicon nitride as a protective barrier for ceramic
blocks in semiconductor processing chambers. Given that the term "silicon
nitride" is generic to a genus of particular compounds (see FF9), with the
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particular chemical composition of "silicon nitride" having a great influence
on the ability of the "silicon nitride" to withstand particular corrosive
etchants (see FF10), it cannot be said that Chang's brief discussion of
depositing silicon nitride in a CVD process is relevant in any way to the
usage of silicon nitride as a barrier for ceramic blocks.
Appellants' third argument, that Chang does not disclose a resistance
heater (App. Br. 9), is not found persuasive. Chang was not used by the
Examiner to disclose a resistance heater; the Examiner found that feature in
Chen. See Ans. 3.
Appellants' final argument, that Todd does not provide a teaching or
motivation to apply its amorphous Si-H-N-O coating to the ceramic block in
Chen (App. Br. 10-11), is not found persuasive. Appellants state that the
disclosure of a type of coating does not teach the use of that coating in a
particular application. App. Br. 11. However, the selection of a known
material based upon its suitability for the intended use is a design
consideration within the skill of the art. In re Leshin, 277 F.2d 197, 199
(CCPA 1960). Todd describes that the disclosed Si-H-N-O materials are
suitable for use as masks to protect against chemical damage such as
oxidation and diffusion from etchants. FF6. The materials described by
Todd thus are known for their resistance to corrosion from etchants. Id. The
Examiner states that one of ordinary skill would use the amorphous
Si-H-N-O composition in Todd for its intended use: to chemically protect
the ceramic block in Chen. Ans. 4. Therefore, the selection of Todd's
composition is merely the selection of a known material, based upon its
suitability to solve the very same corrosion problem the material was known
to solve. The selection of such a composition, from among a finite number
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of identified, predictable compositions with suitable properties, involves
ordinary skill and common sense, not innovation. See KSR, 550 U.S. at 421.

CONCLUSIONS
Appellants have not demonstrated that the Examiner erred in rejecting
claim 1 as unpatentable under 35 U.S.C. § 103(a) by concluding that Chen,
Chang, and Todd, in combination, render obvious the subject matter of the
claim as a whole. In particular, the Examiner has provided reasoning with
rational underpinning for coating the ceramic block described in Chen with a
protective coating, as described in Chang, the protective coating being an
amorphous Si-H-N-O compound, as described in Todd.
Likewise, Appellants have not demonstrated error in the rejections of
claims 2-5, 7, 8, 11-15, and 17 as unpatentable over Chen, Chang or
Berkman, and Brown or Todd; claims 6, 9, and 16 as unpatentable over
Chen, Chang or Berkman, Brown or Todd, and Burkhart or Tachikawa; and
claims 10 and 18-24 as unpatentable over Chen, Chang or Berkman, Brown
or Todd, and Ishii or Hwang.

DECISION
The Examiner's decision is affirmed as to claims 1-24.

AFFIRMED

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