Ex Parte Ko et al

Patent Trial and Appeal Board

Aug 28, 2017

13228011 (P.T.A.B. Aug. 28, 2017)

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.
13/228,011 09/08/2011 Chung-Chi Ko TSMl 1-0728 6677
43859 7590 08/30/2017
SLATER MATSIL, LLP/TSMC
17950 PRESTON ROAD, SUITE 1000
DALLAS, TX 75252
EXAMINER
PHAM, THANH V
ART UNIT PAPER NUMBER
2899
NOTIFICATION DATE DELIVERY MODE
08/30/2017 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):
docketing @ slatermatsil. com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte CHUNG-CHI KO, CHIA-CHENG CHOU,
SHING-CHYANG PAN, KENG-CHU LIN, and
SHWANG-MING JENG
Appeal 2016-008147
Application 13/228,0111
Technology Center 2800
Before DONNA M. PRAISS, N. WHITNEY WILSON, and
MERRELL C. CASHION, JRAdministrative Patent Judges.
PRAISS, Administrative Patent Judge.
DECISION ON APPEAL2
1 The real party in interest is identified as Taiwan Semiconductor
Manufacturing Co., Ltd. App. Br. 2.
2 This opinion makes reference to the Specification filed Sept. 8, 2011 as
amended Jan. 28, 2015 (“Spec.”), the Final Office Action dated Aug. 19,
2015 (“Final Act.”), the Appeal Brief filed Mar. 28, 2016 (“App. Br.”), the
Examiner’s Answer dated July 14, 2016 (“Ans.”), and the Reply Brief filed
Aug. 25, 2016 (“Reply Br.”).
Appeal 2016-008147
Application 13/228,011
STATEMENT OF THE CASE
This is an appeal under 35 U.S.C. § 134(a) from the Final Rejection of
claims 1—11, 13, and 21—26 under 35 U.S.C. § 103(a).3 App. Br. 11. We
have jurisdiction under 35 U.S.C. § 6.
The subject matter of this appeal relates to a plasma treated metal hard
mask. Abstract. Claim 1 is illustrative (disputed matter italicized):
1. A method comprising:
forming a metal hard mask over a low-k dielectric layer,
wherein the step of forming the metal hard mask comprises:
depositing a layer of the metal hard mask comprising
horizontal grains and vertical grains', and
performing a plasma treatment on the layer of the metal
hard mask, wherein after the plasma treatment, the metal hard
mask is substantially free from vertical grains',
patterning the metal hard mask to form an opening; and
etching the low-k dielectric layer to form a trench, wherein
the step of etching is performed using the metal hard mask as an
etching mask.
App. Br. 20 (Claims Appendix).
The Examiner maintains, and Appellants appeal, the rejection of
claims 1—11, 13, and 21—26 under 35 U.S.C. § 103(a) as unpatentable over
the combination of Mistkawi4 and Hytros5 alone or further in view of
RamachandraRao.6 Appellants argue the subject matter common to claims 1
3 The rejections of claims 5 and 27 for double patenting and lack of written
description presented in the Final Action stand withdrawn in view of the
Amendment filed Oct. 8, 2015 canceling claim 27 and amending claim 5.
Final Act. 2—3; Ans. 2. The Amendment was entered by the Examiner in the
Advisory Action dated October 20, 2015.
4 Mistkawi et al., US 2008/0318435 Al, published Dec. 25, 2008.
5 Hytros et al., US 2003/0124842 Al, published July 3, 2003.
6 RamachandraRao et al., US 8,080,475 B2, issued Dec. 20, 2011.
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Application 13/228,011
and 21 and rely on those same arguments for dependent claims 2—7 and 22—
26. App. Br. 17—18. Appellants separately argue claims 9—11. Id. at 17. In
accordance with 37 C.F.R. § 41.37(c)(l)(iv), and in the absence of argument
directed to the subsidiary rejection of claim 8, claims 2—8 and 21—26 will
stand or fall together with independent claim 1 and claim 13 will stand or
fall together with independent claim 9.7
OPINION
The dispositive issues for this appeal are:
1. Did the Examiner reversibly err in finding that the arrangement of
grains required by claim 1 is inherently formed in the deposited
layer of the combined teachings of the prior art?
2. Did the Examiner reversibly err in finding that the plasma
treatment layer of Hytros would produce the same result as the
plasma treatment step of claim 1 ?
3. Did the Examiner reversibly err in determining that it would have
been obvious to one of ordinary skill in the art to substitute boron
nitride (recited in claim 9) as an equivalent for titanium nitride
disclosed by Mistkawi in the titanium nitride sub-layers taught by
Hytros?
After review of the arguments and evidence presented by both
Appellants and the Examiner, we affirm the stated rejections.
7 We group claim 8 with claim 1 rather than with claim 9 because claim 8
depends from claim 1 and Appellants’ arguments concerning claim 9 are not
pertinent to the rejection of claim 8.
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Application 13/228,011
Claims 1 and 21
It is the Examiner’s position that the combination of Mistkawi and
Hytros suggests the subject matter of claims 1—7 and 21—26 for the reasons
stated on pages 3—7 of the Final Action.
In the Appeal Brief, Appellants argue that the Examiner erred in
finding that Mistkawi’s deposited metal hard mask would inherently
comprise both horizontal and vertical grains as required by claim 1 because
Mistkawi’s disclosed metal hard mask has the possibility of having an
amorphous structure, a crystalline structure with only one single grain, all
horizontal grains, or all vertical grains in addition to the possibility of having
both horizontal and vertical grains. App. Br. 12—13. Appellants also
contend that “Mistkawi fails to disclose the forming temperature, which is a
factor affecting the structure of a hard mask layer” whereas the hard mask
layer forming temperature disclosed in the Specification is between about
200°C and about 450°C. App. Br. 13—14; Spec. 19. Regarding the
combination of Mistkawi with Hytros’ plasma treatment, Appellants further
assert that a skilled artisan would not “be able to know that a metal hard
mask substantially free from vertical grains is advantageous, and hence
would not try to adjust the process conditions in a plasma treatment to make
the metal hard mask substantially free from vertical grains.” Id. at 15.
Appellants also argue that the bombardment effect of plasma treatment
requires that the level of kinetic energy is high enough to convert vertical
grains to horizontal grains, providing as an example of the concept hitting a
brick wall with a small rubber ball a million times versus a large lead ball
once or several times to knock bricks off from the brick wall. Id. at 15—16.
According to Appellants, “one of ordinary skill in the art will not recognize
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that the power of the treatment, the treatment time, and the temperature are
result-effective variable[s]” to find workable plasma treatment conditions
because Mistkawi and Hytros fail to teach the advantageous feature of a hard
mask having all horizontal grains. Id. at 16.
The Examiner responds that paragraph 13 of the Specification and
related Figure 2D disclose that all situations of grains being vertical,
horizontal, or slanted are present in the mask layer. Ans. 2. The Examiner
further responds that “[t]he only parameter of temperature mentioned by
appellants [with respect to the deposition of a hard mask having the claimed
structure comprising horizontal grains and vertical grains] is overlapped in
Hytros et al.” Id. at 3 (citing Hytros ^fl[ 47, 57). The Examiner finds that
Hytros discloses “many different variable parameters such as flow rate, RF
power density, chamber pressure and deposition rate in addition to ‘the
substrate [being] heated to a substrate temperature between about 400°C to
about 700°C.”’ Id. (quoting Hytros 1 57). Regarding the plasma treatment
of the deposited hard mask, the Examiner finds that Appellants’ disclosed
timing parameter for the plasma treatment “between about 1 second and
about 10 seconds” (Spec. 110) is overlapped by Hytros’ disclosure that
“[t]he titanium film (titanium nitride layer) may be plasma treated for a time
period between about 5 seconds and about 60 seconds,” Ans. 4 (citing
Hytros ^fl[ 50, 60).
In the Reply Brief, Appellants argue that because there are four other
possibilities in addition to both horizontal grains and vertical grains being
present in a hard mask, the presence of both horizontal grains and vertical
grains is merely a possibility and not a condition that is inherently present.
Reply Br. 4. Regarding the temperature overlap with the prior art deposition
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process, Appellants argue “even if the temperature is a result-effective
variable for [a] certain property of the hard mask, it still cannot be concluded
that the optimized temperature for that specific property will result[] in the
hard mask [having] both horizontal grains and vertical grains.” Id.
Regarding the plasma treatment, Appellants argue that “Hytros only teaches
the plasma treatment of titanium nitride layer using nitrogen-containing gas,
and fails to teach the power, the treatment time, and the temperature.
Accordingly, Hytros fails to realize the power, the treatment time, and the
temperature are result-effective variables and one of ordinary skill in the art
will not be motivated to adjust these parameters.” Id. at 5—6. Appellants
further argue that conversion of substantially all vertical grains into
horizontal grains would not conclusively result even if the parameters are
optimized. Id. at 6.
We are not persuaded that the Examiner erred in rejecting claims 1
and 21 over the combination of Mistkawi and Hytros for the reasons stated
by the Examiner. Final Act. 3—6; Ans. 2-4. We add the following primarily
for emphasis.
The problem with Appellants’ argument that a skilled artisan would
not have optimized the conditions of the deposition and plasma treatment of
the cited prior art references to achieve the effect on the vertical and
horizontal grains as claimed is that the cited prior art references disclose
operating conditions overlapping those of Appellants’. Appellants do not
dispute the Examiner’s findings that the cited prior art overlaps Appellants’
disclosed deposition temperature and plasma treatment time of the deposited
hard mask (Ans. 3—4). Nor do Appellants dispute that the only variable
parameter in forming (depositing) Appellants’ metal hard mask is the
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temperature of the wafer during deposition of between about 200°C and
about 450°C (Ans. 2—3). In addition, Appellants’ argument in the Reply
Brief that the presence of both horizontal and vertical grains is only a
possibility does not adequately rebut the Examiner’s finding that paragraph
13 of Appellants’ Specification and accompanying Figure 2D show that
vertical, horizontal, and slant grain situations all are present in the deposited
metal hard mask layer (Ans. 2).
Appellants’ argument that Hytros fails to disclose the “the power, the
treatment time, and the temperature are result-effective variables” for its
plasma process (Reply Br. 6) does not adequately rebut the Examiner’s
finding that Hytros discloses multiple conditions for its plasma treatment
including an overlapping time period between about 5 seconds and about 60
seconds (Ans. 4). The Examiner specifically finds that Hytros also discloses
an RF power density, a substrate temperature range, and a chamber pressure
in addition to its treatment time (Ans. 4, citing Hytros | 60). Appellants do
not direct us to any evidence that the conditions disclosed in Hytros would
not inherently produce the claimed horizontal and vertical grain
characteristics required by claims 1 and 21. Appellants’ reiteration in its
Reply Brief that the horizontal and vertical grains required by the claims are
not inherently present because four additional grain characteristics are
possible (Reply Br. 4) is unpersuasive given the lack of evidence in support
thereof. See In re Geisler, 116 F.3d 1465, 1471 (Fed. Cir. 1997) (argument
by counsel cannot take the place of evidence).
On this record, the Examiner provided a reasonable basis to establish
that the hard mask and the resulting product from the method of the
combined teachings of Mistkawi and Hytros would have the respective
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claimed characteristics of comprising horizontal and vertical grains and of
being substantially free from vertical grains. Thus, the burden of proof is on
Appellants to prove that the metal hard mask deposited and plasma treated
under the overlapping conditions of Hytros does not necessarily or
inherently possess the claimed horizontal and vertical grain characteristic.
See In re Best, 562 F.2d 1252, 1255 (CCPA 1977) (“[T]he PTO can require
an applicant to prove that the prior art products do not necessarily or
inherently possess the characteristics of his claimed product. . . . Whether
the rejection is based on ‘inherency’ under 35 U.S.C. § 102, on ‘prima facie
obviousness’ under 35 U.S.C. § 103, jointly or alternatively, the burden of
proof is the same, and its fairness is evidenced by the PTO's inability to
manufacture products or to obtain and compare prior art products.” (footnote
omitted)). No such proof has been provided by Appellants.
In sum, Appellants’ arguments are not persuasive of reversible error
in the rejection of claims 1—8, 13, and 21—26.
Claims 9—11
The Examiner finds that the combination of Mistkawi, Hytros, and
RamachandraRao suggests the subject matter of claims 9-11 for the reasons
stated on pages 7—10 of the Final Action.
Appellants argue that the Examiner’s rejection of claim 9 is in error
because none of the cited references “teaches or suggests using boron nitride
to form a metal hard mask, let alone the boron nitride comprises a plurality
of sub-layers.” App. Br. 17. Appellants additionally argue that claims 10
and 11, which depend directly or indirectly from claim 9 and require
converting vertical grains to horizontal grains, are allowable for “similar
reasons” presented with respect to claim 1. Id.
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The Examiner responds that it would have been obvious to one of
ordinary skill in the art at the time of the invention to substitute boron nitride
as an equivalent for titanium nitride or tantalum nitride in view of
Mistkawi’s teaching that “[t]he metal hard mask layer includes metals or
metallic compound such as Ti, Ta, TiN, or TaN, or the like.” Ans. 4.
Regarding claims 10 and 11, the Examiner’s response is the same as that
provided with respect to claim 1. Id. at 5.
In the Reply Brief, Appellants argue that Mistkawi’s teaching of
titanium nitride and the like would “at most” inform a skilled artisan to
replace titanium nitride with boron nitride. Reply Br. 7. Appellants contend
that the Examiner erred by failing to show “there is a teaching that the boron
nitride with distinguishable sub-layers is equivalent to titanium nitride with
distinguishable sub-layers.” Id.
We are not persuaded by Appellants’ arguments. Appellants do not
direct us to any evidence that a person having ordinary skill in the art would
not understand Mistkawi’s disclosure of equivalent mask materials to
include boron nitride. Moreover, Appellants do not argue any criticality
resulting from the use of boron nitride as a hard mask material. Further,
Appellants do not adequately explain or provide a technical rationale for
why a skilled artisan would not expect an otherwise equivalent metal hard
mask material to have equivalent sub-layers. We are not persuaded by
Appellants’ arguments that a person with ordinary skill in the art would not
have a reasonable expectation of success with substitutable materials in such
a structure. Accordingly, we are not persuaded of reversible error in the
rejection of claim 9.
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For the reasons discussed above in connection with claim 1, we also
are not persuaded by Appellants’ additional arguments regarding claims 10
and 11.
Conclusion
For the foregoing reasons, we affirm all of the Examiner’s rejections
under 35 U.S.C. § 103(a).
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(l)(v).
AFFIRMED
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