Ex Parte Ruelke et al

Board of Patent Appeals and Interferences

Oct 13, 2009

10835411 (B.P.A.I. Oct. 13, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte HARTMUT RUELKE, KATJA HUY,
and KARLA ROMERO
____________

Appeal 2008-004114
Application 10/835,411
Technology Center 1700
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Decided: October 13, 2009
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Before BRADLEY R. GARRIS, CHARLES F. WARREN, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.

GARRIS, Administrative Patent Judge.

DECISION ON APPEAL

Appellants appeal under 35 U.S.C. § 134 from the Examiner’s
decision rejecting claims 1-26. We have jurisdiction under 35 U.S.C. § 6.
We AFFIRM for the reasons expressed in the Answer and below.
Appeal 2008-004114
Application 10/835,411

Statement of the Case
Appellants claim a method of forming a layer, such as a silicon
dioxide cap layer (claim 1) or an anti-reflective layer (claim 12), comprising
forming an amorphous carbon layer and depositing silicon dioxide from
TEOS in a plasma atmosphere on the amorphous carbon layer at a
temperature of approximately 370°C or less.
Appellants’ claimed invention is adequately represented by
independent claims 1 and 12, which read as follows:
1. A method of forming a silicon dioxide cap layer, the method
comprising:

forming an amorphous carbon layer above a substrate; and

depositing silicon dioxide from TEOS in a plasma atmosphere on said
amorphous carbon layer at a temperature of approximately
370°C or less to form said cap layer with a thickness in the
range of approximately 5-50 nm, said amorphous carbon layer
and said cap layer cooperating to form an anti-reflective layer.

12. A method of forming an anti-reflective layer, the method
comprising:

forming a material layer to be patterned above a substrate;

forming an amorphous carbon layer of a first thickness above said
material layer;

forming a silicon dioxide layer of a second thickness at a temperature
of less than or equal to 370°C on said amorphous carbon layer;

wherein said first and second thicknesses are selected so as to generate
a reflectivity at a specified exposure wavelength that is
approximately 2% or less.

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Application 10/835,411

The references set forth below are relied upon by the Examiner as
evidence of obviousness:
Azuma 5,759,746 Jun. 2, 1998
Lim 6,406,975 B1 Jun. 18, 2002
Miyasaka 2002/0192885 A1 Dec. 19, 2002
Under 35 U.S.C. § 103(a), the Examiner rejects claims 12-14 and 17-
20 as being unpatentable over Azuma in view of Miyasaka and
correspondingly rejects claims 1-11, 15, 16, and 21-26 as being unpatentable
over these references and further in view of Lim.
Concerning the base rejection over Azuma and Miyasaka, the
Examiner concludes that
[i]t would have been obvious to one of ordinary skill in the
art at the time of the invention to modify Azuma . . . to
include depositing the silicon dioxide layer by TEOS plasma
at a temperature of 370°C or less as taught by Miyasaka in
order to create a silicon dioxide layer with excellent coverage

(Ans. 5).
Issue
Have Appellants shown error in the Examiner’s conclusion that it
would have been obvious to deposit the silicon dioxide layer desired by
Azuma via TEOS plasma at a temperature of 370°C or less as taught by
Miyasaka?
Findings of Fact
The Examiner finds that Azuma discloses a method of forming an
anti-reflective layer comprising forming an amorphous carbon layer and
forming a CVD silicon dioxide layer on the amorphous carbon layer (Ans.
para. bridging 4-5 and para. bridging 9-10; Azuma, col. 5, ll. 13-34, and col.
6, ll. 19-22).
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Application 10/835,411

The Examiner acknowledges that Azuma’s method does not deposit
the silicon dioxide layer by the technique of TEOS plasma at a temperature
of 370°C or less but finds that Miyasaka teaches depositing a silicon dioxide
layer via this technique in order to create a layer with excellent coverage
(Ans. 5, first full para.; Miyasaka, paras. [0156] and [0164]).
Appellants have not contested these findings with any reasonable
specificity in the record of this appeal.
Principles of Law
The question to be asked in assessing the obviousness of a claim to a
combination of prior art elements is whether the improvement obtained by
the claimed combination is more than the predictable use of prior art
elements according to their established functions. KSR Int’l Co. v. Teleflex
Inc., 550 U.S. 398, 417 (2007).
In assessing obviousness, it is erroneous to look only to the problem
an applicant was trying to solve since, under the correct analysis, any need
or problem known in the field of endeavor at the time of invention can
provide a reason for combining the elements in the manner claimed. Id. at
420.
Analysis
Appellants do not argue the dependent claims separately from
independent claims 1 and 12 (see Br. 5-9). Accordingly, the dependent
claims will stand or fall together with these independent claims.
Appellants argue that Azuma and Miyasaka provide no motivation or
reasonable expectation of success for combining their teachings in the
manner proposed by the Examiner (Br. 7-9). In this regard, Appellants
emphasize that neither of these references appreciates that a significant
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Appeal 2008-004114
Application 10/835,411

reduction in defect rate is achieved when forming an anti-reflective layer
with a silicon dioxide cap deposited via the claimed TEOS plasma technique
as compared to a silicon oxynitride cap (Br. 7 and 8, first full paras.; Spec.
paras. bridging 7-8 and 8-9, last para. at 18).
Appellants reveal no error by pointing out that the applied prior art
does not address the defect rate problem that Appellants were trying to
solve. This is because, under the correct analysis, any need or problem
known in the field of endeavor at the time of invention can provide a reason
for combining prior art elements (e.g., the method steps under consideration)
in the manner claimed. Furthermore, non-obviousness is not indicated by
Appellants’ determination that forming a silicon dioxide cap in an anti-
reflective layer as claimed solves the defect rate problem exhibited by a
silicon oxynitride cap. This is because Azuma, like Appellants, forms an
anti-reflective layer with a cap of silicon dioxide rather than silicon
oxynitride. For all we know, based on the record of this appeal, Azuma’s
method of forming an anti-reflective layer with a silicon dioxide cap yields
the same defect rate reduction (i.e., compared to a silicon oxynitride cap) as
Appellants’ claimed method.
Appellants also fail to reveal error by arguing that Azuma and
Miyasaka provide no motivation or reasonable expectation of success for
combining their teachings in the manner proposed by the Examiner.
Azuma’s method includes forming a silicon dioxide layer via a CVD
technique. Significantly, Miyasaka evinces that it was known in the prior art
that a silicon dioxide layer would be formed with excellent coverage via a
plasma-enhanced CVD technique using TEOS at temperatures within
Appellants’ claimed range. Based on the record of this appeal, forming the
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Application 10/835,411

silicon dioxide layer desired by Azuma via the prior art technique taught by
Miyasaka would have been nothing more than the predictable use of prior art
elements (e.g., Miyasaka’s silicon dioxide deposition technique) according
to their established functions.
Concerning the rejection of independent claim 1 over Azuma,
Miyasaka, and Lim, Appellants additionally argue that “there is no
motivation to combine Lin [sic, Lim] with Azuma” (Br. para. bridging 8-9).
However, this argument reveals no error on the Examiner’s part because it
does not address the Examiner’s position concerning these applied
references. Contrary to the implication of Appellants’ argument, the
Examiner does not propose to modify Azuma by combining it with Lim.
Instead, the Examiner relies on Lim solely to support the proposition that it
is technically accurate to characterize the silicon dioxide layer of Azuma as
a cap layer (Ans. 6, second and third full paras.). Significantly, this
proposition has not been contested by Appellants with any reasonable
specificity.
Conclusions of Law
Appellants have not shown error in the Examiner’s conclusion that it
would have been obvious to deposit the silicon dioxide layer desired by
Azuma via TEOS plasma at a temperature of 370°C or less as taught by
Miyasaka.
For this reason, we sustain the Examiner’s § 103 rejections of claims
12-14 and 17-20 over Azuma and Miyasaka and of claims 1-11, 15, 16, and
21-26 over Azuma, Miyasaka, and Lim.
Order
The decision of the Examiner is affirmed.
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Appeal 2008-004114
Application 10/835,411

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

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