An-Ren Zi et al.

Patent Trials and Appeals Board

Jan 22, 2020

15019836 - (D) (P.T.A.B. Jan. 22, 2020)

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.
15/019,836 02/09/2016 An-Ren Zi P20151244US00/24061.3317U 6673
42717 7590 01/22/2020
HAYNES AND BOONE, LLP (24061)
IP Section
2323 Victory Avenue
Suite 700
Dallas, TX 75219
EXAMINER
CHU, JOHN S Y
ART UNIT PAPER NUMBER
1737
NOTIFICATION DATE DELIVERY MODE
01/22/2020 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
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PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte AN-REN ZI and CHING-YU CHANG

Appeal 2019-000108
Application 15/019,836
Technology Center 1700
____________

Before KAREN M. HASTINGS, RAE LYNN P. GUEST,
DONNA M. PRAISS, Administrative Patent Judges.

PRAISS, Administrative Patent Judge.

DECISION ON APPEAL1

Pursuant to 35 U.S.C. § 134(a), Appellant2 appeals from the
Examiner’s decision to reject claims 1–17 and 24–26. We have jurisdiction
under 35 U.S.C. § 6(b).
We AFFIRM.

1 In this Decision, we refer to the Specification filed Feb. 9, 2016 (“Spec.”),
the Final Office Action dated Sept. 27, 2017 (“Final Act.”), the Appeal Brief
filed Feb. 23, 2018 (“Appeal Br.”), the Examiner’s Answer dated Aug. 3,
2018 (“Ans.”), and the Reply Brief filed Oct. 2, 2018 (“Reply Br.”).
2 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. Taiwan Semiconductor Manufacturing Co., Ltd., is
identified as the real party in interest. Appeal Br. 3.
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Application 15/019,836

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STATEMENT OF THE CASE
The invention relates to a lithography method for manufacturing a
semiconductor device. Spec. ¶ 11. Claims 1 and 9, reproduced below, are
illustrative of the subject matter on appeal (disputed limitations italicized).
1. A method comprising:
forming a photoresist over a substrate, wherein the
photoresist includes an acid-labile group (ALG) bonded to a
polymer backbone and to a polar unit such that the polar unit is
acid-cleavable from the polymer backbone;
exposing the photoresist to a radiation beam;
baking the photoresist, wherein at least one of the
exposing and the baking cleaves the polar unit and the ALG
from the polymer backbone within an exposed portion of the
photoresist; and
performing a developing process to the photoresist.
9. A method comprising:
forming a photoresist over a substrate, wherein the
photoresist includes an acid-labile group (ALG) bonded to a
photoresist backbone and bonded to a polarity switch unit;
exposing the photoresist to a radiation beam to thereby
increase the polarity of the polarity switch unit;
baking the photoresist, whereby at least one of the
exposing and the baking separates the ALG and the polarity
switch unit from the photoresist backbone; and
performing a developing process to the photoresist.
Appeal Br. 13, 14 (Claims Appendix).

ANALYSIS
We review the appealed rejections for error based upon the issues
Appellant identifies, and in light of the arguments and evidence produced
thereon. Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010) (precedential)
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(cited with approval in In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011)
(“[I]t has long been the Board’s practice to require an applicant to identify
the alleged error in the examiner’s rejections.”). After considering the
argued claims and each of Appellant’s arguments, we are not persuaded of
reversible error in the appealed rejections.
The Examiner rejects claims 1–17 and 24–26 under 35 U.S.C. § 103
as unpatentable over Nishi.3 Final Act. 2–6.
Appellant separately argues the rejection of independent claims 1 and
9, and relies on arguments presented with respect to claim 1 for the rejection
of independent claim 24. Appeal Br. 9–11. Therefore, in view of the lack of
arguments directed to dependent claims 2–8, 10–17, and 24–26, claims 2–8
and 24–26 stand or fall with independent claim 1 and claims 10–17 stand or
fall with independent claim 9. 37 C.F.R. § 41.37(c)(1)(iv). We separately
address claims 1 and 9 below.

Claim 1
Appellant contends the Examiner erred in rejecting claim 1 over Nishi
because the Examiner fails to explain how the prior art is being applied to
the claim. Appeal Br. 8. Regarding the Examiner’s finding that, when R2 is,
for example, an isopropyl group in Nishi’s general formula (1) it forms an
acid labile portion bonded to a polar lactone group (Final Act. 4–5),
Appellant asserts that “Nishi does not disclose that the R2 group can
function as an ALG in the resin polymer.” Appeal Br. 9. Appellant argues
that even if Nishi’s R2 group could function as an ALG, Nishi “does not
teach or suggest that the polar lactone group is acid-cleavable from a

3 US 2003/0054289 A1, published Mar. 20, 2003.
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polymer backbone in any regard, much less that the photoresist includes an
acid-labile group (ALG) bonded to a polymer backbone and to a polar unit
such that the polar unit is acid-cleavable from the polymer backbone as
recited in independent claim 1.” Id. at 10.
The Examiner responds that the claim terms “acid-labile” and “acid-
cleavable” have essentially identical meanings and are synonymous with
“acid-dissociable,” “acid sensitive,” and “acid-decomposable.” Ans. 3. The
Examiner finds “acid-labile” and “acid-cleavable” mean these groups can be
cleaved or removed where the tertiary carbon bond attaches to the carboxylic
acid oxygen in the presence of an acid. Id. The Examiner finds that Nishi
discloses in formula (1) a group which may be acid-cleavable depending on
the definition of R2. Id. at 6. Specifically, the Examiner finds that one skilled
in the art would understand that when R2 is a straight, branched, or cyclic
alkyl group having 1 to 8 carbon atoms, as taught by Nishi as an option for
formula (1), the polar unit is acid-cleavable from the polymer backbone at
the tertiary carbon shown in formula (1). Id. at 4–5. The Examiner annotates
Nishi’s formula (1) as reproduced below in context with Nishi’s paragraphs
7–9.
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Nishi’s formula (1) above is annotated with bubble 1 pointing to an acid-
labile tertiary carbon group and bubble 2 pointing to a polar unit attached
through the acid-labile carbon tertiary group to the polymer backbone. Id. at
4–5.
The Examiner also directs us to Nishi’s paragraphs 18 and 19
annotated below. Id. at 5–6.
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Annotated paragraphs 18 and 19 depict general formula (2) highlighting the
location and definition of variable R6, also as optionally being “a straight,
branched or cyclic alkyl group,” that would render the attached carbon a
tertiary carbon. Thus, the Examiner finds the definition of R6 is similar to
that of R2 and in the same position as R2 in formula (1). Id. at 5. The
Examiner finds that Nishi discloses in paragraphs 18 and 19 an “acid-
decomposable protecting group containing an adamantine structure,”
therefore, this demonstrates that the tertiary carbon group (bubble 1)
attached to the carboxyl’s oxygen is known to be acid-labile and/or acid-
decomposible. Id. at 6.
Regarding claim 1’s requirement that the “acid-labile group (ALG)
[is] bonded to a polymer backbone and to a polar unit such that the polar unit
is acid cleavable from the polymer backbone,” the Examiner finds that Nishi
discloses the claimed structure regardless of whether the claim requires that
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the polar unit is on the same or a separate repeating unit on the polymer
backbone. Id. at 6–8. The Examiner annotates Nishi’s example polymer (1)
in two ways as shown below.

In each of the annotated polymer (1) structures, the Examiner identifies the
acid-labile group (ALG) with an “A” and the polar unit as “1.” Id. at 7–8.
In the Reply Brief, Appellant contends that the Examiner takes
Official Notice without documentary evidence as to whether a tertiary
carbon group is known to be acid-cleavable, acid-labile, acid-dissociable
and/or acid-decomposable. Reply Br. 7. Appellant asserts that this is not
common knowledge in the art. Id. Appellant argues that the assertion the
tertiary carbon bonded to R2 in Nishi’s general formula (1) itself being an
acid-cleavable group is not supported by the definition of R6 because “Nishi
appears to suggest that the portion of each of general formulae (2)–(4) that is
bonded to the carboxylic acid and that contains an adamantine structure––
rather than a particular carbon atom alone––functions as an acid-
decomposable protecting group.” Id. at 8. Because Nishi’s formula (1) does
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not disclose any adamantine group, Appellant asserts that “Nishi does not
explicitly disclose that general formula (1) includes any acid-decomposable
group.” Id. at 7.
Regarding the polar unit required by claim 1, Appellant does not
dispute the Examiner’s factual findings of a tertiary carbon and a polar
group taught by Nishi, but, rather, argues that, absent evidence to support a
tertiary carbon (when R2 is an alkyl group) is known to be acid-cleavable,
Nishi fails to teach or suggest a photoresist including an acid-labile group
(ALG) bonded to a polymer backbone and to a polar unit as required by
claim 1. Id. at 8–9.
Appellant’s arguments do not persuade us that the Examiner
reversibly erred in rejecting claim 1 as obvious over the teachings of Nishi.
Specifically, we are not persuaded that the Examiner erred in finding that
Nishi’s disclosure in paragraphs 18 and 19 teaches or suggests that the
structure of formula (2) is acid-decomposable due to the tertiary carbon
component of the structure, which is also present in general formula (1)
when R2 is a straight, branched, or cyclic alkyl group. Appellant’s assertion
(Reply Br. 7) that the rejection is in error because Nishi does not “explicitly
disclose that general formula (1) includes any acid-decomposable group” is
not persuasive of error because an obviousness analysis “need not seek out
precise teachings directed to the specific subject matter of the challenged
claim.” KSR Int’l Co. v. Teleflex, Inc., 440 U.S. 418 (2007). Moreover, Nishi
discloses that there are a variety of acid labile groups including tertiary alkyl
groups of 4 to 20 carbons. Nishi ¶ 35.4

4 Indeed, Appellant’s Specification identifies that an exemplary ALG “may
include a bulky unit with a tertiary carbon as a good leaving group.”
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Appellant’s argument (Reply Br. 8) that Nishi’s disclosure of an acid-
decomposable protecting group is limited to those containing an adamantine
structure as depicted in general formulae (2)–(4) is not persuasive of error
because Appellant does not adequately explain why one skilled in the art
would understand the adamantine structure rather than the tertiary carbon
itself being responsible for the acid-decomposable characteristic of general
formula (2). In a determination of obviousness, a reference may be relied
upon for all that it would have reasonably suggested to one having ordinary
skill in the art. Merck & Co. v. Biocraft Labs., 874 F.2d 804, 807 (Fed. Cir.
1989) (“That the [prior art] patent discloses a multitude of effective
combinations does not render any particular formulation less obvious.”).
Moreover, “a reference is not limited to the disclosure of specific working
examples.” In re Mills, 470 F.2d 649, 651 (CCPA 1972) (citation omitted).
The preponderance of the evidence in this appeal record therefore
supports the Examiner’s conclusion that the claimed subject matter would
have been obvious in view of Nishi. Accordingly, we affirm the Examiner’s
rejection of claim 1 under 35 U.S.C. § 103(a) over Nishi for the above
reasons and those provided by the Examiner.
Because we find Appellant’s arguments unpersuasive of error in the
Examiner’s rejection of claim 1 for the reasons discussed above, we likewise
affirm the Examiner’s rejection of claims 2–8 and 24–26 for the same
reasons.

Spec. ¶ 15. This is consistent with the teachings of Nishi and the Examiner’s
finding that a tertiary carbon in formula (1) would fall within the scope of
the clamed ALG.
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Claim 9
Appellant contends that the Examiner erred in rejecting claim 9
because Nishi does not disclose any of the components of general formula
(1) as a polarity switch unit. Appeal Br. 10–11.
The Examiner responds that Nishi discloses that the carbon bonded to
the carboxyl oxygen becomes a tertiary carbon when R2 is an alkyl group
from formula (1) and an acid-labile group. Ans. 9. Referring to Nishi’s
polymer (1), the Examiner finds that when the acid-labile group is cleaved
upon contact with an acid it leaves a carboxylic acid group and the polarity
has switched from a hydrophobic group to a polar group. Id. at 9–10.
In the Reply Brief, Appellant asserts that the Examiner’s finding is not
supported that when R2 is an alkyl group from formula (1), the carbon
bonded to the carboxyl oxygen becomes a tertiary carbon and an acid-labile
group (ALG). Reply Br. 10. Appellant also argues that the Examiner’s
annotated polymer (1) of Nishi identifying unit A as both the acid-labile
group (ALG) and the polarity switch group fails to disclose the recited “the
photoresist includes an acid-labile group (ALG) bonded to a photoresist
backbone and bonded to a polarity switch unit” that “separates the ALG and
the polarity switch unit from the polymer backbone.” Id.
Appellant’s arguments do not persuade us that the Examiner
reversibly erred in rejecting claim 9 over the cited prior art references.
Appellant does not dispute the Examiner’s interpretation (Ans. 3) of acid-
labile group. Nor does Appellant dispute the Examiner’s interpretation of
“acid-labile group (ALG) [being] bonded to [the] polymer backbone and to a
polar unit such that the polar unit is acid cleavable from the polymer
backbone.” Appeal Br. 9. As discussed above in connection with claim 1, we
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are not persuaded that Nishi fails to teach or suggest that when R2 is an alkyl
group from formula (1), the carbon bonded to the carboxyl oxygen becomes
a tertiary carbon and an acid-labile group (ALG). Appellant’s assertion that
the acid-labile group (ALG) and the polarity switch group cannot both be
located on unit A of Nishi’s annotated polymer (1) does not adequately rebut
the Examiner’s finding (Ans. 9–10) that when the acid-labile group is
cleaved upon contact with an acid it leaves a carboxylic acid group and the
polarity has switched from a hydrophobic group to a polar group.
Accordingly, we affirm the Examiner’s rejection of claim 9 under
35 U.S.C. § 103(a). Because we find Appellant’s arguments unpersuasive of
error in the Examiner’s rejection of claim 9 for the reasons discussed above,
we likewise affirm the Examiner’s rejection of claims 10–17 for the same
reasons.
CONCLUSION
For these reasons and those the Examiner provides, we uphold the
Examiner’s rejection of claims 1–17 and 24–26 under 35 U.S.C. § 103 as
obvious over the cited prior art.

DECISION SUMMARY
In summary:
Claim(s)
Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1–17, 24–26 103 Nishi 1–17, 24–26

Appeal 2019-000108
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TIME PERIOD FOR RESPONSE
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