Ex Parte Chen et al

Patent Trial and Appeal Board

Sep 30, 2016

12372111 (P.T.A.B. Sep. 30, 2016)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
12/372,111 02/17/2009 Yu-Chung Chen JCLA28622 9076
23900 7590 09/30/2016
J C PATENTS
4 VENTURE, SUITE 250
IRVINE, CA 92618
EXAMINER
CATHEY JR, DAVID A
ART UNIT PAPER NUMBER
1713
MAIL DATE DELIVERY MODE
09/30/2016 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte ATSUSHI YUSA
____________

Appeal 2014-001510
Application 12/372,111
Technology Center 1700
____________

Before CHUNG PAK, GEORGE BEST, and KIMBERLY McGRAW,
Administrative Patent Judges.

McGRAW, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134(a) from a final rejection of
claims 1–14. We have jurisdiction under 35 U.S.C. § 6(b).
We affirm-in-part.
STATEMENT OF THE CASE
According to the Specification, the invention is directed to making
integrated circuits and controlling the critical dimensions (“CD”) of the
pattern of a second hard mask layer in order to use that layer as a mask for
etching a pattern onto a first hard mask layer having critical dimensions that
are equal to each other. See Spec. ¶¶ 2–3, 4, and 6. The Specification
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explains that the patterned second mask, which has first and second critical
dimensions that are different from each other (CD1≠CD2), is used as a mask
to pattern a first hard mask layer that has third and fourth critical dimensions
that are equal to each other (CD4=CD3). Id. at ¶ 6. Claims 1 and 8 are the
only independent claims on appeal and are reproduced below:
1. A patterning method comprising:
providing a substrate having a first region and a second
region;
successively forming a first hard mask layer and a
second hard mask layer on the substrate;
patterning the second hard mask layer so as to form a
pattern in the second hard mask layer, wherein a first critical
dimension of the pattern in the first region is different from a
second critical dimension of the pattern in the second region;
and
performing an etching process to pattern the first hard
mask layer by using the patterned second hard mask layer as
a mask, wherein the pattern is transferred into the first hard
mask layer with a third critical dimension in the first region
and a fourth critical dimension in the second region and the
third critical dimension is substantially equal to the fourth
critical dimension.

8. A patterning method for being applied over a substrate
having a first region and a second region, comprising:
forming a first hard mask layer over the substrate;
forming a second hard mask layer on the first hard
mask layer;
patterning the second hard mask layer by transferring a
pattern onto the second hard mask layer so that the patterned
second hard mask layer possesses a first critical dimension in
the first region and a second critical dimension in the second
region; and
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performing an etching process on the first hard mask
layer by using the patterned second hard mask layer as a mask
so as to transfer the pattern onto the first hard mask layer,
wherein
the portion of the pattern in the first hard mask layer in
the first region has a first sidewall profile with a first obliquity
and the portion of the pattern in the first hard mask layer in
the second region has a second sidewall profile with a second
obliquity and the first obliquity is different from the second
obliquity.
App. Br. 7–8 (Claims App’x).
REJECTIONS ON APPEAL
Claims 1, 3–8, and 10–14 stand rejected under 35 U.S.C. § 103(a)
over Kushibiki et al., (US 2005/0070111 A1) and Ohiwa et al., (SiO2
Tapered Etching Employing Magnetron Discharge of Fluorocarbon Gas,
Vol. 31 part 1, No. 2A Jpn J. Appl. Phys. 405–410(1992). Final Act. 3.
Claims 2 and 9 are rejected under 35 U.S.C. 103(a) as being
unpatentable over Kushibiki, Ohiwa, and Egbe et al., (US 2006/0293208
A1). Final Act. 11.
ISSUES
1. Does the principle of operation of Kushibiki require CD1=CD2
and therefore, it would not have been obvious to modify Kushibiki in any
way that would result in CD1≠CD2?
2. Did the Examiner err in rejecting claims 1–7 because the
Examiner has not identified a sufficient motivation to modify Kushibiki in
view of Ohiwa such that CD1≠CD2 and CD3=CD4, as required by
independent claim 1?
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ANALYSIS
We have reviewed the rejections of claims 1–14 in light of
Appellants’ arguments that the Examiner erred. In doing so, we have
evaluated only the arguments that Appellants actually make on appeal.
Arguments that Appellants could have made but declined to make are
waived. See 37 C.F.R. § 41.37(c)(1)(iv).
Appellants state claims 1‒7 should be treated as a group and claims 8‒
14 as another group. App. Br. 3. For the reasons explained below, we
reverse the Examiner’s rejection of claims 1–7 and affirm the Examiner’s
rejection of claims 8–14.
ISSUE 1
Appellants contend the Examiner erred in combining the deposition
and etching steps of Kushibiki into a single step, as taught by Ohiwa,
arguing the combination would change the “principle of operation” of
Kushibiki of providing a BARC layer (second hard mask) having a critical
dimension in a first region (CD1) equal to a critical dimension in a second
region (CD2). App. Br. 2, 4–5 (citing In re Ratti, 270 F.2d 810 (CCPA
1959). Specifically, Appellants contend that because “the technique of
‘depositing polymer on sidewalls and etching’ . . . was common knowledge
in the art,” “the operation principle of Kushibiki should be ‘depositing
polymer on sidewalls of the photoresist patterns (212) and etching to unify
the CD of the second hard mask (210) (CD2=CD1).’” Id. at 5 (emphases
removed). Appellants contend that Kushibiki’s “principle of making
‘CD2=CD1’” is diametrically opposed to “the principle of ‘CD2≠CD1’ of the
modification required for meeting the limitation in independent claims 1 &
8.” Id.
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This argument is not persuasive with respect to claim 8 because,
contrary to Appellants’ assertions, claim 8 does not require CD2≠CD1.
Appellants have not adequately explained how their arguments relating to
critical dimensions (CD) apply to the limitations of claim 8. Therefore,
Appellants’ arguments are not persuasive of Examiner error regarding the
rejection of claim 8 or claims 9–14 which depend therefrom.
Appellants also do not provide persuasive argument as to why the
“principle of operation” should be defined so narrowly so as to preclude any
modification to the critical dimensions (CD1=CD2) of the second mask layer.
The “principle of operation” referred to by Appellant relates to the “basic
principles” under which the prior art device was designed to operate. In
re Ratti, 270 F.2d 810, 813 (“This suggested combination of references
would require a substantial reconstruction and redesign of the elements
shown in [the primary reference] as well as a change in the basic principles
under which the [primary reference] construction was designed to operate.”
(emphasis added)). A “change in the basic principle” by which a prior art
method operates does not occur by any modification of that method.
Otherwise, even nominal modifications to prior art could be considered a
“change in the basic principles.”
The Examiner found that the desired end result of both Kushibiki and
Ohiwa is to achieve a finally desired circuit pattern. Final Act. 14–15. The
Examiner also found that the principles of operation of both references for
achieving the desired circuit pattern are polymer deposition from a CHF3
plasma on sidewalls and etching. Id. The Examiner further found that
because the principles of operation of polymer deposition on sidewalls and
etching are the same principles, and the end result is the same, the references
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are combinable and do not change the principles of operations. Id.
Appellants’ arguments (see App. Br. 4–5) are not persuasive of Examiner
error.
ISSUE 2
Appellants assert the Examiner erred in rejecting independent claim 1
because there is no suggestion or motivation to modify Kushibiki to provide
a method in which a patterned second hard mask, which has a first critical
dimension that is different than a second critical dimension (CD1≠ CD2), is
used in an etching process to pattern a first hard mask having a third critical
dimension that is equal to a fourth critical dimension (CD3=CD4). App. Br.
4–5. Appellants state that Kushibiki teaches a process in which a second
mask, having first and second critical dimensions that are equal to each other
(CD1=CD2), is used to pattern a first hard mask having third and fourth
critical dimensions that are also equal to each other (CD3=CD4). Appellants
state that there is no suggestion or motivation to modify Kushibiki such that
CD1≠ CD2 and CD3=CD4. Id.
We agree with Appellants. The Examiner admits that Kushibiki fails
to disclose a process in which CD1≠CD2, but states this is because Kushibiki
deposits the sidewall polymer in a separate step from etching the SiO2 mask
layer 208. Final Act. 6; Ans. 7. The Examiner contends that Ohiwa teaches
the deposition and etching steps can be combined into a single step and that
if the deposition and etching steps were combined, then CD1≠ CD2. Final
Act. 6; Ans. 7–8. The Examiner concludes that one of ordinary skill in the
art would have combined the deposition and etching steps so as to simplify
manufacturing, reduce costs, and increase productivity. Ans. 7–8, 16–17.
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However, the Examiner does not adequately explain why one of
ordinary skill would understand that modifying the method of Kushibiki
such that CD1≠CD2 would result in a first hard mask having a third and
fourth critical dimension equal to each other (CD3=CD4). The Examiner
states
Whereby the combination would have resulted in the first critical
dimension in the first region and second critical dimension in the
second region of the second hard mask 210 of modified
Kushibiki having different critical dimensions, specifically the
second critical dimension in the second region (reg 12) low
density region being smaller than the first critical dimension in
the first region (reg 11) high density region, because the polymer
deposition step of modified Kushibiki to provide uniform critical
dimensions (widths) in reg 12 and reg 11 would have occurred
after etching 210 with photomask 212 having smaller dimensions
in reg 12 than reg 11.
Ans. 8. However, these findings do not address whether the modification
would result in CD3=CD4.
The Examiner also states
The CD’s [sic] that Kushibiki is concerned with are the
dimensions of the etched target and CD3 = CD4 (the critical
dimensions /widths of the hardmask features 208) in order to
provide for uniform etched target dimensions, which were
achieved in both Kushibiki and Ohiwa modified Kushibiki. The
modification of the method of Kushibki provides the same
desired result of Kushibiki employing the same starting point of
Kushibiki but with a motivated modification of combining steps,
whereby Kushibiki and modified Kushibiki both employ the
disposable BARC of Kushibiki to provide suppression of light.
Ans. 17.
These findings also do not adequately explain how one of ordinary
skill in the art would understand that the modified method of Kushibiki,
where a second hard mask having CD1≠CD2 is used to pattern a first hard
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mask, would result in the first hard mask having a third and fourth critical
dimension equal to each other (CD3=CD4). See KSR Int’l Co. v. Teleflex
Inc., 550 U.S. 398, 418 (2007) (“[R]ejections on obviousness grounds
cannot be sustained by mere conclusory statements; instead, there must be
some articulated reasoning with some rational underpinning to support the
legal conclusion of obviousness.”). As such, we agree with Appellants that
the Examiner has not demonstrated the disputed limitation of claim 1 would
have been obvious to a skilled artisan at the time of invention.
In view of the forgoing, we find the Examiner erred in rejecting
independent claim 1 and claims 2–7 depending therefrom.
DECISION
The Examiner’s rejection of claims 1–7 under 35 U.S.C. § 103 is
reversed.
The Examiner’s rejection of claims 8–14 are 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). See 37 C.F.R.
§ 1.136(a)(1)(iv).
AFFIRMED-IN-PART