Ex Parte Chuang et al

Board of Patent Appeals and Interferences

Jan 7, 2010

10708642 (B.P.A.I. Jan. 7, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte CHIN-CHUNG CHUANG, SHIN-JIEN KUO,
CHAO-YUN CHENG, and SHU-FENG WU
____________

Appeal 2009-006845
Application 10/708,642
Technology Center 1700
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Decided: January 07, 2010
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Before ALLEN R. MACDONALD, Chief Administrative Patent Judge,
EDWARD C. KIMLIN, and TERRY J. OWENS,
Administrative Patent Judges.

KIMLIN, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal from the final rejection of claims 1-5, 8-12, and 21.
We have jurisdiction under 35 U.S.C. § 6(b).
Claim 1 is illustrative:

Appeal 2009-006845
Application 10/708,642

1. A front-end array process for making a liquid crystal display
panel, comprising:

depositing a molybdenum-containing metal layer on a glass substrate,
wherein said molybdenum-containing metal layer is a dual-metal layer;

forming a patterned photoresist on said molybdenum-containing metal
layer, wherein said patterned photoresist defines a gate and word line array
pattern; and

using said patterned photoresist as an etching mask, uniformly etching
said molybdenum-containing metal layer to form said gate and word line
array pattern having substantially oblique sidewalls, wherein said etching of
said molybdenum-containing metal layer uses gas mixture, wherein said
etching of said molybdenum-containing metal layer is detected by an end-
point detection method.

The Examiner relies upon the following references as evidence of
obviousness (Ans. 4):
Przybysz 4,904,980 Feb. 27, 1990
Kim 4,981,816 Jan. 01, 1991
Cheung 5,354,417 Oct. 11, 1994
Hori 5,445,710 Aug. 29, 1995
Rioux 5,554,488 Sep. 10, 1996
Hong 6,429,057 B1 Aug. 06, 2002
Celii 2003/0143853 A1 Jul. 31, 2003
Nagata JP 05-067590A Mar. 19, 1993

Appellants’ claimed invention is directed to a process for making a
liquid crystal display panel. The process entails forming a photoresist
pattern defining a gate and word line array pattern on a molybdenum-
containing metal layer and photolithographically etching the pattern into the
metal layer wherein the pattern has substantially oblique sidewalls. The
etchant is a mixture of gases.
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Appeal 2009-006845
Application 10/708,642

The appealed claims stand rejected under 35 U.S.C. § 103(a) as
follows:
(a) claims 1 and 21 over Hong in view of Rioux and Kim,
(b) claim 2 over Hong, Rioux, Kim, and Przybysz,
(c) claims 3, and 9-12 over Hong, Rioux, Kim, and Hori,
(d) claim 4 over Hong, Rioux, Kim, and Cheung,
(e) claim 5 over Hong, Rioux, Kim, and Celii, and
(f) claim 8 over Hong, Rioux, Kim, and Nagata.
Appellants do not present separate arguments for any particular claim
on appeal, and only address the rejections of independent claims 1 and 21.
In addition, Appellants do not make a separate, substantive argument for
claim 21. Accordingly, all the appealed claims stand or fall together with
claim 1.
We have thoroughly reviewed each of Appellants’ arguments for
patentability. However, we are in complete agreement with the Examiner
that the claimed subject matter would have been obvious to one of ordinary
skill in the art within the meaning of § 103 in view of the applied prior art.
Accordingly, we will sustain the Examiner’s rejection for essentially those
reasons expressed in the Answer, and we add the following primarily for
emphasis.
Appellants do not dispute the Examiner’s factual determination that
Hong, like Appellants, discloses a front-end array process for making a
liquid crystal display panel comprising photolithographically etching a
molybdenum-containing metal gate layer with a gaseous etchant mixture.
As acknowledged by the Examiner, Hong is silent with respect to the etched
pattern having the presently claimed substantially oblique sidewalls.
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Appeal 2009-006845
Application 10/708,642

However, Appellants have not refuted the Examiner’s finding that it was
known in the art that photolithographic etching of metal patterns does not
produce a perfectly vertical sidewall but necessarily forms an oblique
sidewall. Furthermore, Rioux evidences that it was known in the art that the
controlled, gaseous photolithographic etching of metal layers to produce a
gate structure forms oblique sidewalls. This is clearly depicted in Figures 1
and 2 of Rioux which represent the prior art. Accordingly, we find no error
in the Examiner’s conclusion that it would have been obvious to one of
ordinary skill in the art that the etched metal pattern of Hong has oblique
sidewalls, particularly since “Rioux teaches it avoids undercutting, and etch
damage in subsequent process (ab), an [sic, a] known process improvement”
(Ans. 5, penultimate para.).
Appellants maintain that the tapered sidewalls of Rioux are “not
formed by etching but by deposition” (App. Br. 14, first para.). Appellants
contend that the deposition of the conductive layer 48 of Rioux is the
essential reason for forming the tapered gate structure 54 (Id. at second
para.). However, Appellants’ argument misses the thrust of the Examiner’s
rejection. The Examiner’s rejection is based upon the background section of
Rioux, which clearly teaches that it was known in the art to form oblique
sidewalls on metal gate patterns by photolithographically etching with a
gaseous mixture. Appellants’ argument focuses upon the deposition process
of Rioux but does not address the background disclosure of the reference
that is clearly illustrated in Figures 1 and 2.
As a final point, we note that Appellants base no argument upon
objective of non-obviousness, such as unexpected results.
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Appeal 2009-006845
Application 10/708,642

In conclusion, based on the foregoing, the Examiner’s decision
rejecting the appealed claims is affirmed.

No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a) (2008).

AFFIRMED

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