Ex Parte Varadarajan et al

Patent Trial and Appeal Board

Jan 10, 2018

12646830 (P.T.A.B. Jan. 10, 2018)

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.
12/646,830 12/23/2009 Bhadri Varadarajan NOVLP330/NVLS-3565 1835
83422 7590 01/12/2018
Weaver Austin Villeneuve & Sampson - LAMR/NOVL
P.O. BOX 70250
OAKLAND, CA 94612-0250
EXAMINER
TRAN, TONY
ART UNIT PAPER NUMBER
2894
NOTIFICATION DATE DELIVERY MODE
01/12/2018 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):
USPTO@wavsip.com
eofficeaction @ appcoll.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte BHADRI VARADARAJAN,
GEORGE A. ANTONELLI, and
BART VAN SCHRAVENDIJK
Appeal 2017-002912
Application 12/646,830
Technology Center 2800
Before KAREN M. HASTINGS, JULIA HEANEY, and
DEBRA L. DENNETT, Administrative Patent Judges.
DENNETT, Administrative Patent Judge.
DECISION ON APPEAL1
Appellants2 appeal under 35 U.S.C. § 134(a) from a rejection of
claims 22—24, 26—34, 36—39, 41, 42, and 45—59. We have jurisdiction under
35 U.S.C. § 6(b).
We AFFIRM-IN-PART.
1 In our Opinion, we refer to the Specification filed December 23, 2009
(“Spec.”); the Final Action mailed February 2, 2016 (“Final Act.”); the
Appeal Br. filed August 2, 2016 (“Appeal Br.”); the Examiner’s Answer
mailed October 28, 2016 (“Ans.”); and the Reply Brief filed December 28,
2016 (“Reply Br.”).
2 Appellants identify Novellus Systems, Inc. as the real party in interest.
Appeal Br. 3.
Appeal 2017-002912
Application 12/646,830
The subject matter on appeal relates to semiconductor processing
methods for treating carbon-containing low dielectric constant (low-k)
dielectric materials with a reducing agent and ultraviolet (UV) radiation for
repair of process-induced damage and removal (reduction) of metal oxide.
Spec. 19. Low-k materials are used to address reduced feature sizes and
high performance requirements in semiconductor devices. Id. 12. Low-k
materials are less dense than standard insulating materials such as SiCL,
which can result in difficulties in process integration and material
compatibility. Id. 1 5. Maintaining the integrity of low-k materials
undergoing processes including stripping, cleaning, and conditioning is
challenging. Id.
In a typical damascene process flow, prior to metal barrier deposition,
damage to a patterned low-k dielectric can occur as a result of a variety of
processes. Id. 17. In addition, excess metal deposited on the patterned
dielectric layer to fill vias and trenches must be removed via chemical
mechanical polishing, which damages the low-k dielectric. Id. Exposed
metal is subject to oxidation prior to the formation of a dielectric barrier of
subsequent layers on the wafer surface. Id. ^ 8. Oxides and other residue
are removed by cleaning processes such as reducing plasma, but plasmas
also affect the low-k dielectric. Id.
The methods of the invention are said to be particularly applicable in
the context of damascene processing to recover lost low-k properties of a
dielectric damaged during processing. Id. 19.
Claims 22 and 28, reproduced below with disputed limitations
italicized, are illustrative of the claimed subject matter:
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22. A method of forming a semiconductor device,
comprising:
receiving in a processing chamber a semiconductor
device substrate comprising a planarized surface having
conductive features in a dielectric layer; and
exposing the planarized surface to UV radiation and a
reducing agent, without exposing the planarized surface to a
plasma, wherein the reducing agent is a reducing gas selected
from the group consisting of NH3, NH2D, NHD2, ND3, H2,
N2H4, and combinations of these with one another and/or inert
gases;
whereby oxide on the conductive features is removed in a
UV-mediatedplasma-free process including exposure to a non­
oxidizing reducing environment.
28. A method of forming a semiconductor device,
comprising:
receiving in a processing chamber a semiconductor
device substrate comprising conductive features and a dielectric
layer having formed therein a feature; and
exposing the semiconductor device substrate to a
reducing agent and UV radiation, without exposing the device
substrate to a plasma, wherein the reducing agent is a reducing
gas selected from the group consisting of NH3, NH2D, NHD2,
ND3, H2, N2H4, and combinations of these with one another
and/or inert gases, such that oxide on the conductive features is
removed in a UV-mediated plasma-free process including
exposure to a non-oxidizing reducing environment.
Appeal Br. 32, 33 (Claims App’x).
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Application 12/646,830
REFERENCES
The Examiner relies on the follow prior art in rejecting the claims on
appeal:
Chen et al.
(“Chen”)
Dimitrakopoulos et al.
(“Dimitrako-poulos”)
Lai et al. (“Lai”)
Ramkumar et al.
(“Ramkumar”)
Singh et al.
(“Singh”)
US 2007/0161230 Al
US 2007/0228570 Al
US 2008/0026579 Al
US 2009/0243001 Al
US 2010/0018460 Al
July 12, 2007
Oct. 4, 2007
Jan. 31, 2008
Oct. 1, 2009
Jan. 28, 2010
REJECTIONS
The Examiner maintains the following grounds of rejection3:
1. Claims 58 and 59 stand rejected under 35 U.S.C. § 112, first
paragraph as failing to comply with the written description requirement.
Final Act. 2; Appeal Br. 8—9.
2. Claims 22—24, 26—34, 36, 39, 41, 42, 45—50, and 52—59 stand
rejected under 35 U.S.C. § 103(a) over Lai in view of Chen. Final Act. 3—14;
Appeal Br. 10-26.
3. Claim 37 stands rejected under 35 U.S.C. § 103(a) over Lai and
Chen, and further in view of Singh. Final Act. 14; Appeal Br. 26—28.
4. Claim 38 stands rejected under 35 U.S.C. § 103(a) over Lai and
Chen, and further in view of Dimitrakopoulos. Final Act. 15; Appeal Br.
28-29.
3 Because this application was filed before the March 16, 2013 effective date
of the America Invents Act, we refer to the pre-AIA version of the statutes.
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Application 12/646,830
5. Claim 51 stands rejected under 35 U.S.C. § 103(a) over Lai and
Chen, and further in view of Ramkumar. Final Act. 15—16; Appeal Br. 29—
30.
OPINION
Rejection 1: lack of written description
Claims 58 and 59 recite, inter alia, “a planarized surface having
conductive features in a porogen-free dielectric layer.” Appeal Br. 39
(Claims App’x). The Examiner finds the claims lack written description
because “porogen-free” is not found and supported in the Specification.
Final Act. 2.
Appellants argue that newly added claim limitations need not be
recited in haec verba in the original application, and that paragraph 6 of the
Specification describes the invention in sufficient detail to allow one skilled
in the art to reasonably conclude that the inventors had possession of the
claimed invention. Appeal Br. 8—9. In particular, Appellants argue that the
Specification explains that low-k dielectrics may be formed by introducing
porosity, and it is known in the art that porosity can be introduced by
removing a porogen from a dielectric material. Id. at 9. Paragraph 6 states
that “[introducing porosity . . . yield[s] a lower dielectric constant film.”
Spec. 1 6.
The Examiner acknowledges the statement in paragraph 6, but
responds that nothing in the original disclosure mentions a porogen-free
dielectric layer, and therefore the written description requirement is not met.
Ans. 3.
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The Specification’s disclosure that low-k dielectrics may be formed
by introducing porosity is insufficient written description support for the
limitation in claims 58 and 59 that the dielectric layer is porogen-free.
“Although the exact terms need not be used in haec verba, . . , the
specification must contain an equivalent description of the claimed subject
matter,” Lockwood v. American Airlines, Inc., 107 F.3d 1565, 1572 (Fed.
Cir. 1997). “It is not sufficient for purposes of the written description
requirement of § 112 that the disclosure, when combined with the
knowledge in the art, would lead one to speculate as to modifications that
the inventor might have envisioned, but failed to disclose.” Id. The
sufficiency of an application’s written description is a question of fact.
Ariad Pharms., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010)
(en banc). “Introducing porosity,” as stated in the Specification, is not
necessarily accomplished by removing porogens, and does not teach
removal of all porogens, which would be required in order to provide a
“porogen-free” dielectric layer. “[T]he test for sufficiency is whether the
disclosure of the application relied upon reasonably conveys to those skilled
in the art that the inventor had possession of the claimed subject matter as of
the filing date.” AriadPharm., Inc. v. EliLilly & Co., 598 F.3d 1336, 1351
(Fed. Cir. 2010) (en banc). Here, Appellants do not show possession of a
porogen-free dielectric layer.
We sustain the rejection of claims 58 and 59 as lacking written
description.
Rejection 2: obviousness over Lai in view of Chen
All of the pending claims require removal of oxide on the conductive
features of a semiconductor device substrate by a UV-mediated plasma-free
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process. Appeal Br. 32—39 (Claims App’x). Appellants argue that the
combination of Lai and Chen fails to teach this process for oxide removal.
Id. at 10—26.
Appellants argue that Lai teaches removing organic residuals left after
chemical mechanical polishing of a copper damascene structure alternatively
by a UV treatment, and removing impurities on the structure by a reduction
plasma treatment after the UV treatment. Appeal Br. 11. Appellants argue
that Chen teaches two UV treatments, one to decompose porogens in a low-k
dielectric, and a second to harden the dielectric by cross-linking. Id. at 12.
The Examiner finds that Lai and Chen both teach two-step processes.
Ans. 6. The Examiner finds that Chen teaches two consecutive UV
processes in the presence of the copper layer. Id. Chen discloses that a
copper layer is blanket deposited and planarized; the copper fills the dual
damascene trench and via opening. Chen 137. One of the irradiating steps
may include treating the dielectric layer with a carbon-repairing gas. Id. 1
38.
The Examiner finds that Lai teaches performing a UV treatment to
remove residuals generated in the copper damascene process and later a
reduction plasma treatment that can reduce copper oxide completely. Ans. 6
(citing Lai 142). The Examiner finds that Lai’s statement that reduction
plasma treatment can reduce copper oxide completely implies that some of
the copper oxide is removed by Lai’s earlier UV treatment. Id.
The Examiner finds that Lai’s UV treatment is equivalent to Chen’s
first UV treatment and Lai’s reduction plasma treatment is equivalent to
Chen’s second UV treatment. Id. at 7. The Examiner relies in part on
Chen’s teaching that “[a] plasma treatment. . . could improve hardness and
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modules” of a low-k dielectric material, and “lallternatively,. . . and most
preferably, a UV . . . treatment is used.” Id. (citing Chen 125).
Thus, the Examiner finds that one of ordinary skill in the art at the
time of the invention would have used a known technique to improve a
similar device to yield predictable results. The Examiner reasonably finds
that Lai’s UV treatment removes at least some amount of copper oxide,
based on Lai’s statement that the reduction plasma treatment after the UV
treatment can reduce copper oxide completely. See Ans. 6; Lai 142.
Chen’s UV treatments, applied in the presence of the copper layer that has
been planarized, also reasonably remove at least some small amount of
copper oxide. See Chen 137.
The claims do not require all of the oxide, or indeed, any specific
amount of oxide to be removed in a UV-mediated plasma-free process. See
Appeal Br. 32—39 (Claims App’x). Removal of even a minute amount will
satisfy the claims. The claims do not exclude additional steps using plasma,
as the transitional term “comprising” is used.
Lor the reasons above, we agree with the Examiner that the
combination of Lai and Chen teaches removal of oxide on the conductive
features of a semiconductor device substrate by a UV-mediated plasma-free
process.
Appellants separate the claims into the following groups in arguing
for patentability over Lai in view of Chen: (A) claims 22—24, 26, 27, 34, 36,
41, 42, and 53; (B) claims 28—33, 39, 45, 46, 52, and 54; (C) claim 58; (D)
claim 59; (E) claims 47—50; (L) claim 55; (G) claim 56; and (H) claim 57.
Appeal Br. 10, 19, 21—26. We address each group below.
Group A
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Application 12/646,830
Appellants argue patentability of claims 22—24, 26, 27, 34, 36, 41, 42,
and 53 based on the patentability of claim 22. Appeal Br. 17. We,
therefore, limit our discussion of this rejection to the rejection of claim 22.
37C.F.R. §41.37(c)(l)(iv).
Appellants argue that claim 22 is patentable because Lai and Chen do
not teach removal of oxide on the conductive features in a UV-mediated
plasma-free process, and one of ordinary skill in the art would not have had
a reasonable expectation of success in combining the references. See Appeal
Br. 10-18. Both of these issues are addressed supra. In addition, we note
that Appellants support patentability of claim 22 by disputing the
Examiner’s explanation of Lai’s disclosure and attacking the references
individually. One cannot show nonobviousness by attacking references
individually when the rejection is based on a combination of references. In
re Merck & Co., Inc., 800 F.2d 1091, 1097 (Fed. Cir. 1986). Each reference
cited by the Examiner must be read, not in isolation, but for what it fairly
teaches in combination with the prior art as a whole. Id.
Moreover, Appellants provide nothing other than attorney argument in
support of the understanding of one of ordinary skill in the art. See Appeal
Br. 17—18. What a reference would have meant to a person having ordinary
skill in the art is a question of fact. In re Beattie, 974 F.2d 1309, 1311 (Fed.
Cir. 1992) (“What a reference teaches is a question of fact.”). In the absence
of evidence, we accord little probative value to Appellants’ assertion of
“what would be understood by those skilled in the art.” Cf. InreMayne,
104 F.3d 1339, 1344 (Fed. Cir. 1997) (“Even were it obvious to a
practitioner of the art, applicants have the burden to provide the PTO with
evidence showing that such is the case.”).
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For the reason given above, claim 22 is obvious over the combination
of Lai and Chen, and we sustain the rejection. We also sustain the rejection
of claims 23, 24, 26, 27, 34, 36, 41, 42, and 53.
Group B
Appellants argue patentability of claims 28—33, 39, 45, 46, 52, and 54
based on the patentability of claim 28. Appeal Br. 21. Claim 28 is very
similar to claim 22, differing only as follows:
claim 22: receiving in a processing chamber a semiconductor device
substrate comprising a planarized surface having conductive features
in a dielectric layer; and
exposing the planarized surface to UV radiation and a reducing agent,
claim 28: receiving in a processing chamber a semiconductor device
substrate comprising conductive features and a dielectric layer having
formed therein a feature; and
exposing the semiconductor device substrate to a reducing agent and
UV radiation
Appeal Br. 32, 33 (Claims App’x). In other words, claim 22 requires the
semiconductor device substrate to comprise a planarized surface having
conductive features in a dielectric layer, while claim 28 does not require a
planarized surface, but requires the dielectric layer to have a feature formed
therein. Id.
Appellants’ arguments for patentability of claim 28 are essentially the
same as for patentability of claim 22. Therefore, we sustain the rejection of
claim 28 over Lai in view of Chen and also sustain the rejection of claims
29-33, 39, 45, 46, 52, and 54 over these references.
Groups C and D
Appellants separately argue for patentability of claim 58 and claim 59.
Appeal Br. 21—22. Claim 58 is identical to claim 22, with the exception that
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claim 58 requires “conductive features in aporogen-free dielectric layer.”
Id. at 21. Claim 59 has the same resemblance to claim 28. Id. at 22.
In addition to the arguments made for patentability of claims 22 and
28, Appellants contend that neither Lai nor Chen teaches the required
porogen-free dielectric layer.
The Examiner finds that Lai teaches dielectric layers comprising
carbon-doped oxide (CDO). Final Act. 11,12 (citing Lai 121). The
Examiner determines, therefore, that the dielectric layer may be porogen free
if it is carbon-doped oxide.4 Id.
Appellants’ arguments are not persuasive in light of the teaching in
the references. We sustain the rejections of claims 58 and 59.
Group E
Claims 47-50 depend directly or indirectly from claim 28. Claims 47—
50 each recite “wherein the reducing agent is NH3 gas, the exposure to the
reducing agent is conducted at a temperature of about 400-C for less than 1
minute, and the UV radiation exposure is conducted in an inert atmosphere.”
Appeal Br. 37 (Claims App’x).
The Examiner finds that Chen teach the reducing agent is NH3 gas, the
exposure to the reducing agent is conducted at 350-C for about 60 seconds,
and the UV radiation exposure is conducted using UV and H2, N2, NH3, etc.
Final Act. 9-10 (citing Chen || 28, 30).
4 In addition, in the event of further prosecution, we note that Chen teaches
“porous, low-k dielectric formation by degradation of a porogen,” the
dielectric constant of suitable examples of commercial low-k dielectrics
“after porogen removal,” and “[m]ost of the porogen is degraded” after
about 90 seconds of the first UV treatment. Chen || 20, 23, 27.
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Appellants argue that Chen describes performing the second UV
treatment at a temperature of about 350°C for about 60 seconds to perform
cross-linking and provides no guidance for selecting the specific reducing
gas and specific time recited in claims 47—50; Chen only suggests that any
one of the list of gases may be used in any one of the process steps of Figure
3, which includes many operations in addition to UV radiation exposure.
Appellants contend that nothing in Lai cures the deficiencies of Chen.
The Examiner responds that Chen’s teaching of a second UV
treatment at about 350-C for about 60 seconds reads on the claims’
requirements of about 400-C for less than 1 minute because “about 350-C
may be 380-C and about 400-C may be around 380-C.” Ans. 8.
A prima facie case of obviousness typically exists where a claimed
range overlaps a range disclosed in the prior art. In re Peterson, 315 F.3d
1325, 1329 (Fed. Cir. 2003). A prima facie case of obviousness also exists
when the claimed range and the prior art range do not overlap but are close
enough such that one skilled in the art would have expected them to have the
same properties. Titanium Metals Corp. v. Banner, 778 F.2d 775, 783 (Fed.
Cir. 1985) (concluding that a claim directed to an alloy containing “0.8%
nickel, 0.3% molybdenum, up to 0.1% iron and balance titanium” would
have been prima facie obvious in view of a reference disclosing alloys
containing 0.75% nickel, 0.25% molybdenum, balance titanium and 0.94%
nickel, 0.31% molybdenum, balance titanium). However, here, there are no
overlapping ranges. The Examiner’s conclusion that the claimed “about
350-C” “may be 380-C,” and Chen’s disclosure of “about 400-C may be
around 380-C” is unpersuasive at least because the 380-C temperature
appears arbitrarily chosen and based on improper hindsight. The Examiner
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has not provided any reasoning that about 400-C is close enough to about
350-C to expect the same result from a UV treatment at either temperature.
We do not sustain the rejection of claims 47—50.
Groups F and G
Claim 55 depends from claim 22 and claim 56 depends from claim 28,
and both recite “wherein the UV-mediated plasma-free process comprises
exposing the oxide to hydrogen radicals.” Appeal Br. 38 (Claims App’x).
The Examiner finds that Chen teaches exposing the oxide to hydrogen
radicals because Chen teaches use of NH3, therefore the hydrogen radical of
ammonia, and ions of hydrogen material existed in radical form, therefore
this feature is inherent in the process. Final Act. 10; Ans. 10.
Appellants argue that the word “radical” is found nowhere in Chen,
and Chen does not teach use of “the hydrogen radical of ammonia.” Appeal
Br. 24—25. Appellants contend that Chen’s recitation of NH3 among other
gases does not make obvious the presence of hydrogen radicals or exposing
an oxide on a conductive feature to hydrogen radicals.
A preponderance of the evidence supports Appellants’ position that
the Examiner has not shown claims 55 and 56 to be obvious over Lai in view
of Chen. We do not sustain the rejections.
Group H
Claim 57 depends from claim 22 and further requires “wherein the
dielectric layer is porous.” Appeal Br. 38 (Claims App’x).
The Examiner finds that Chen teaches a porous dielectric layer. Final
Act. 11 (citing Chen Title (“UV Curing of Low-K Dielectrics”), Fig. 2a, and
1125,27).
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Appellants argue that the dielectric layer in Chen only has pores after
exposure to UV radiation, but UV radiation is used to remove pores and
form a cross-linked dielectric and does not involve removing oxide on
conductive features.
The Examiner responds that Chen teaches that the dielectric layer
before treatment is porous. Ans. 10.
In Chen, UV radiation removes porogens, not pores. See Chen 125.
Chen teaches that the first UV treatment preferably decomposes the porogen
from within the low-k dielectric, thereby forming pores. Id. “Most of the
porogen is degraded and the pores suitably formed after about 90 seconds.”
Id. 128.
Appellants do not overcome the Examiner’s rejection of claim 57,
which we sustain.
Rejection 3: obviousness of claim 37 over Lai and Chen, and further
in view of Singh
Claim 37 depends from claim 22 and further requires “exposing the
dielectric to a silylating agent prior to or during the UV exposure.” Appeal
Br. 35 (“Claims App’x).
The Examiner finds that Singh teaches the additional requirement of
claim 37. Final Act. 14 (citing Singh || 50, 56, 64—65). The Examiner
concludes that it would have been obvious to one of ordinary skill in the art
at the time of the invention to include the teaching of Singh into the
combination of Lai and Chen to providing a photoexcitation and surface
treatment as taught by Singh. Id.
Appellants argue that Singh discloses a method for depositing films
using a UV source. Appeal Br. 27. Appellants contend that nothing in the
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paragraphs cited by the Examiner suggests that they teach exposing a
dielectric to a silylating agent prior to or during UV exposure. Id.
Appellants argue that one of ordinary skill in the art would have no
motivation to expose the substrate to a silylating agent prior to or during UV
exposure from the description in any of Chen, Lai, or Singh. Id.
The Examiner responds that it would have been obvious to include
Singh’s teaching in the combination of Lai and Chen to enhance cross-
linking between Si and N, which may cause Si—N bond distortion in the SiN
network, as taught by Singh. Ans. 11.
Singh discloses that intermediates of silane and NH3, NH2, and NH in
an excited state enhances cross-linking between Si and N, and the resulting
bond distortion in the Si—N network is desirable for increasing film tensile
stress. Singh | 65.
Appellants have not explained why the reason articulated by the
Examiner for combining the references is erroneous or unreasonable. See In
re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006).
We sustain the rejection of claim 37 over Lai and Chen in further
view of Singh.
Rejection 4: obviousness of claim 38 over Lai and Chen, and further
in view of Dimitrakopoulos
Claim 38 depends from clam 28 and further requires “wherein the UV
and reducing agent exposure reduces oxide created in a via silicide.” Appeal
Br. 35 (Claims App’x).
The Examiner depends on the earlier rejection of claim 28, and finds
that Dimitrakopoulos teaches that UV and reducing agent exposure reduces
oxides created in a via silicide such as metal silicide. Final Act. 15 (citing
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Dimitrakopoulos 145). The Examiner concludes that it would have been
obvious to one of ordinary skill in the art at the time of the invention to
include Dimitrakopoulos’ teaching for repairing CMP-induced damage in
the combination of Lai and Chen. Id.
Appellants argue that Dimitrakopoulos discloses a method of
improving fabrication of an interconnect structure using chemical
mechanical polishing and UV exposure to improve the reliability of a porous
ultralow-k dielectric of the SiCOH type. Appeal Br. 28 (citing
Dimitrakopoulos Abstract). Appellants argue that Dimitrakopoulous’s metal
silicide is an example of conductive material that the invention may be
performed on, and how a conductive material is deposited, but nothing in
Dimitrakopoulous describes exposure of an oxide created in a via silicide to
UV and a reducing agent. Id. at 28—29 (citing Dimitrakopoulous ]Hf 45 and
64). Instead, according to Appellants, Dimitrakopoulous teaches using UV
exposure to form a gradient layer which is a thin oxide-like layer on top of
an ultralow-k dielectric. Id. at 29 (citing Dimitrakopoulous 1 67).
The Examiner responds that one could have substituted the copper
(metal) material of Lai with the metal silicide material of Dimitrakopoulous,
and the UV radiation step by a chemical repair step, making it reasonable to
combine Lai and Dimitrakopoulos to yield a predictable result. Ans. 12—13.
Appellants contend that if one replaced Lai’s UV treatment with
Dimitrakopoulos’ chemical repair step, the combined process would not
result in a UV-mediated plasma-free process including exposure to a non­
oxidizing reducing environment. Reply Br. 6.
If, as the Examiner suggests, one substituted Lai’s copper material
with Dimitrakopoulos’ metal silicide material and the UV radiation step by a
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chemical repair step, the resulting process would not one that is UV-
mediated or plasma-free, and not meet the limitations of claim 38.
Therefore, we do not sustain the rejection of claim 38.
Rejection 5: obviousness of claim 51 over Lai and Chen, and further
in view of Ramkumar
Claim 51 depends from claim 28 and further requires “wherein the
reducing gas is selected from the group consisting of NH2D, NHD2, and
ND3.” Appeal Br. 38 (Claims App’x).
The Examiner depends on the earlier rejection of claim 28, and finds
that Ramkumar teaches the additional element in disclosing “an NH3 or ND3
atmosphere is provided at anneal operation 305 to reduce the silicon-rich
sites.” Final Act. 15 (citing Ramkumar 14).
Appellants suggest that the Examiner intended to cite 140 of
Ramkumar, which describes various ambients for an anneal process. Appeal
Br. 29. Appellants contend that nothing in 140 or elsewhere in Ramkumar
suggests using NH2D, NHD2, and ND3 as a reducing gas when exposing a
semiconductor device substrate to a reducing agent and UV radiation to
remove oxide on conductive features. Id. at 30.
The Examiner responds that ND3 is changed to NH3 because of its
unstable state, and it is therefore reasonable to combine Ramkumar with Lai
to provide another form of NH3 to use with UV treatment. Ans. 13.
“[Rejections 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.” KSRIntj Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007).
Here, the required articulated reasoning with rational underpinning is
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lacking in the combination of Ramkumar with Lai and Chen. We do not
sustain the rejection of claim 51.
DECISION
For the above reasons, the Examiner’s rejection of claims 22—24, 26—
34, 36—37, 39, 41, 42, 45, 46, 52—54, and 57—59 is affirmed. The
Examiner’s rejection of claims 38, 47—51, 55, 56 is reversed.
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)(iv) (2015).
AFFIRMED-IN-PART
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