Ex Parte LI et al

Patent Trials and Appeals Board

Apr 29, 2019

14884984 - (D) (P.T.A.B. Apr. 29, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
14/884,984 10/16/2015 YuzhuoLI
22850 7590 05/01/2019
OBLON, MCCLELLAND, MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA, VA 22314
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
ATTORNEY DOCKET NO. CONFIRMATION NO.
46l 638US99DIV 1068
EXAMINER
DUCLAIR, STEPHANIE P.
ART UNIT PAPER NUMBER
1713
NOTIFICATION DATE DELIVERY MODE
05/01/2019 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):
patentdocket@oblon.com
OBLONPAT@OBLON.COM
iahmadi@oblon.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte YUZHUO LI and KEW ANG
Appeal2018-007241
Application 14/884,984
Technology Center 1700
Before MICHAEL P. COLAIANNI, JEFFREY B. ROBERTSON, and
GEORGE C. BEST, Administrative Patent Judges.
ROBERTSON, Administrative Patent Judge.
DECISION ON APPEAL 1
STATEMENT OF THE CASE
Appellant2 appeals under 35 U.S.C. § 134(a) from the Examiner's
Final Rejection of claims 19, 21, 22, and 24--39. (Appeal Br. 1.) We have
jurisdiction pursuant to 35 U.S.C. § 6(b ).
We AFFIRM.
1 This Decision includes citations to the following documents: Specification
filed October 16, 2015 ("Spec."); Final Office Action dated June 26, 2017
("Final Act."); Appeal Brief filed December 20, 2017 ("Appeal Br."); and
Examiner's Answer dated May 4, 2018 ("Ans.").
2 Appellant is the Applicant, BASF SE, which is identified as the real party
in interest. (Appeal Br. 1.)
Appeal2018-007241
Application 14/884,984
THE INVENTION
Appellant states that the invention relates to chemical-mechanical
polishing compositions and methods. (Spec. 1, 1. 6.)
Claim 19 is representative and reproduced below from the Claims
Appendix to the Appeal Brief:
19. A method for the chemical-mechanical planarization of a
substrate comprising at least one copper layer, at least one
ruthenium layer, and at least one tantalum layer, wherein said
tantalum layer comprises tantalum or tantalum nitride, said
method comprising:
( 1) providing a chemical-mechanical polishing
composition comprising
(a) at least one type of abrasive particle;
(b) at least one persulfate oxidizing agent (b 1) and
at least one periodate oxidizing agent (b2), wherein the
persulfate oxidizing agent (b 1) increases the material
removal rate of a tantalum layer and the periodate
oxidizing agent (b2) reacts with a ruthenium layer, and
simultaneously forms a strong oxide film on a copper
surface;
( c) at least one pH adjusting agent;
( d) deionized water;
( e) optionally comprising at least one antioxidant;
(2) contacting the substrate surface to be polished with a
chemical-mechanical polishing composition and a
polishing pad; and
(3) chemically and mechanically polishing the substrate
surface by way of moving the polishing pad relative to
the substrate,
wherein the at least one copper layer and the at
least one ruthenium layer are in contact and at least one
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Application 14/884,984
tantalum layer is disposed between the at least one
ruthenium layer and at least one dielectric layer.
(Appeal Br. i, Claims Appendix.)
REJECTION
The Examiner rejected claims 19, 21, 22, and 24--39 under 35 U.S.C.
§ 103 as obvious over Brusic et al. (US 2008/0105652 Al, published May 8,
2008, "Brusic"), Small et al. (US 2008/0038995 Al, published February 14,
2008, "Small"), Wang et al. (US 6,316,365 Bl, issued November 3, 2001,
"Wang"), and Grumbine et al. (US 2008/0057715 Al, published March 6,
2008, "Grumbine").
Appellant presents arguments for claim I9's patentability. (See
Appeal Br. 4.) Accordingly, we select claim 19 as representative for
disposition of this appeal. 37 C.F.R. § 4I.37(c)(l)(iv).
ISSUE
The Examiner found that Brusic discloses a method for chemical-
mechanical planarization of a substrate comprising at least one copper layer,
at least one ruthenium layer, and at least one tantalum layer as recited in
claim 19. (Final Act. 2-3.) The Examiner found that Brusic discloses a
chemical-mechanical polishing composition as recited in claim 19 including
a persulfate oxidizing agent (b 1 ), but Brusic is silent as to a periodate
oxidizing agent (b2). (Id. at 3.)
The Examiner found that Small discloses a method for chemical
mechanical planarization of a substrate including a metal layer (including
copper), a noble metal layer (including ruthenium), and a barrier layer
(including tantalum) where Small identifies periodate oxidizing agent as
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Application 14/884,984
useful for polishing selected noble metals including ruthenium, as well as
the use of additional oxidizers including monopersulfates. (Id. at 3--4.) The
Examiner determined that it would have been obvious to have modified the
method of Brusic to include an additional oxidizing agent as a second
oxidizing agent, because Small discloses additional oxidizing agents may be
used in conjunction with periodic acid oxidizer such that one of ordinary
skill in the art would have had a reasonable expectation of success of
predictably achieving the desired polishing using Small's two oxidizers. (Id.
at 4.)
The Examiner found that Grumbine discloses a chemical planarization
method including periodate oxidizing agent and an additional persulfate
oxidizing agent, which is used to polish a combination of layers including
copper, ruthenium, and tantalum. (Id.) The Examiner found that Grumbine
further discloses including both oxidizing agents to increase the polishing
rate of both tantalum and ruthenium, which renders obvious the recitation
that the persulfate oxidizing agent increases the removal rate of the tantalum
layer. (Id.) The Examiner determined that it would have been obvious to
have modified Brusic' s method to include dual oxidizing agents where the
persulfate oxidizing agent increases the removal rate of a tantalum layer as
in Grumbine, because one of ordinary skill in the art would have had a
reasonable expectation of predictably achieving the desired polishing using
Grumbine's oxidizers. (Ans. 5.)
The Examiner found that Wang discloses a method of chemical
mechanical planarization comprising tantalum and a conductive metal
wherein the composition comprises a persulfate compound wherein the
conductive metal film can be copper, ruthenium, and any combination
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Application 14/884,984
thereof. (Id.) The Examiner determined that Brusic as modified by Small,
Grumbine, and Wang renders the claimed method utilizing the claimed
composition obvious. (Id.)
The Examiner found that although Brusic modified by Small,
Grumbine, and Wang does not explicitly disclose simultaneously forming a
strong oxide on a copper surface, the combined teachings render obvious
treating a substrate with a composition that renders obvious the claimed
method and composition, because a chemical composition and its properties
are inseparable. (Id. 5---6.) The Examiner additionally determined that
Small, Grumbine, and Wang disclose including adjusting the components of
the composition in order to attain the desired polished substrate and
polishing rates for each layer rendering obvious the limitation that the
persulfate oxidizing agent increases the removal rate of the tantalum layer
and the periodate oxidizing agent reacts with the ruthenium layer,
simultaneously forming a strong oxide film on a copper surface. (Id. at 5-
6.)
Appellant argues that the Examiner's rejection is not sustainable
because there would be no reasonable expectation of success in modifying
Brusic as proposed by the Examiner. (Appeal Br. 3--4, 7-8, and 10-13.) In
particular, Appellant argues that Brusic relates to a completely different
approach than Small and cannot be modified to include at least one periodate
oxidizing agent based on Small. (Id. at 5-7.) In addition, Appellant argues
that Small, Grumbine, and Wang do not disclose a substrate having all of the
layers in the substrate disclosed in claim 19, such the skilled artisan would
not be led to apply the combination of periodate and persulfate to the
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Application 14/884,984
combination of layers on the specific substrate of the present invention. (Id.
at 4--5 and 9-10.)
Appellant argues that, contrary to the Examiner's findings, Grumbine
does not disclose a periodate oxidizing agent; rather, Grumbine discloses a
halogen adduct resulting from the reaction of an oxidizing agent selected
from iodine or bromine in combination with a carbon acid, where periodate
salt is used to generate iodine in situ. (Id. at 8-9.) Appellant argues that
Grumbine does not disclose that the removal rate of tantalum is increased
through the inclusion of a persulfate oxidizing agent, but that with only one
exception, Grumbine discloses that the second oxidizing agent decreases the
tantalum polishing rate, which amounts to a teaching away from the use of
persulfate oxidizer. (Id. at 9, 13.)
Accordingly, the issue on appeal is:
Has Appellant identified reversible error in the Examiner's position
that the combination of persulfate oxidizing agent and periodate oxidizing
agent in the chemical-mechanical polishing composition recited in claim 19
would have been obvious over Brusic, Small, Wang, and Grumbine?
OPINION
We are not persuaded by Appellant's arguments that one of ordinary
skill in the art would have lacked a reasonable expectation of success in
combining persulfate oxidizing agent and periodate oxidizing agent in a
chemical-mechanical polishing composition as recited in claim 19. Rather,
we are of the view that the preponderance of the evidence supports the
Examiner's position that the recited combination of oxidizers would have
been obvious to one of ordinary skill in the art. Our reasoning follows.
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As the Examiner found, Brusic discloses the substrate arrangement
having the copper, ruthenium, and tantalum layers recited in claim 19.
(Brusic, ,r 43; Final Act. 2-3.) Brusic further discloses an oxidizing agent,
including a persulfate salt, the function of which "is to oxidize at least a part
of a substrate, such as a layer or layers comprising copper, ruthenium, and/or
tantalum." (Brusic, ,r 20.) Small discloses oxidizers, including
combinations of oxidizers, for use in chemical-mechanical polishing
compositions, and specifically discloses that iodates, including periodate
salts "are useful in polishing selected noble metals, including ruthenium."
(Small, ,r 72.) Small discloses that monopersulfates are also suitable in
combinations of oxidizers. (Small, ,r 73.) Wang discloses that persulfate is
included in "tantalum-selective polishing compositions." (Wang, col. 3, 11.
6-8, col. 4, 11. 58-63.) Thus, one of ordinary skill in the art would have
understood that combinations of oxidizers, including combinations of
periodates and monopersulfates, would be useful in chemical-mechanical
polishing compositions, and in particular in substrates including ruthenium
and tantalum.
As the Examiner determined, in view of the disclosures of the prior
art, it would have been obvious to have included a combination of periodate
and persulfate oxidizers, which would result in a strong oxide being formed
on a copper surface as recited in claim 19. (Final Act. 5-6.) Appellant has
not challenged this determination on the part of the Examiner.
We are not persuaded by Appellant's argument that Brusic discloses a
different approach such that combining the disclosure of Small with Brusic
would not create a reasonable expectation of success for one of ordinary
skill in the art. Initially, we agree with the Examiner that it is of no moment
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that Brusic does not mention Small throughout the course of its disclosure.
(Ans. 6, (citing In re Wright, 569 F.2d 1124, 1127 (CCPA 1977)).) A
person of ordinary skill in the art would have all prior art references
available to them as of the filing date of the application at issue. (See In re
Winslow, 365 F.2d 1017, 1020 (C.C.P.A. 1966) ("[P]icture the inventor as
working in his shop with the prior art references-which he is presumed to
know-hanging on the walls around him.").)
In addition, we are not persuaded by Appellant's argument that Brusic
is directed to a different approach by using an additional polishing
composition to remove the bulk of copper present. (Appeal Br. 7.) Brusic
discloses that most of the copper lying outside of the substrate features is
removed by a copper polishing composition, and the "inventive polishing
composition" is used to remove substantially all of the ruthenium and
tantalum as well as residual copper lying outside the substrate features to
expose the underlying dielectric material. (Brusic, ,r 46.) Claim 19's
method includes the transitional phrase "comprising," which would include
the presence of other steps such as the initial copper polishing step disclosed
in Brusic. Indeed, the Specification discloses that excess copper lying
outside the trenches and vias of the substrate is removed by "one or more
chemical-mechanical polishing processes." (Spec. 12, 11. 1-5.) Thus, claim
19 does not exclude an additional polishing step as disclosed in Brusic.
With respect to the discussion of Brusic in the Specification pointed to
by Appellant (Appeal Br. 6-7 (citing Spec. 4, 1. 8 to 5, 1. 5)), we agree with
the Examiner that such a discussion does not address the Examiner's
rejection as a whole, but rather focuses only on Brusic. (Ans. 5.) Although
Brusic itself discusses alternative approaches to controlling material removal
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rates, such approaches do not limit one of ordinary skill in the art from
considering any approaches available in the prior art. Again, we emphasize
that claim 19 is open to the inclusion of additional method steps and
additional components in the chemical-mechanical polishing composition.
Appellant's arguments focused on the disclosure of Small, Grumbine,
and Wang with respect to the specific substrates disclosed therein being
different than claim 19' s structure recited are also not persuasive. ( Appeal
Br. 4--5, 9, and 10.) As discussed above, the prior art provides guidance as
to oxidizers that are useful for removing specific layers of substrates, in
particular emphasizing the use and effectiveness of periodate for removal of
ruthenium and persulfate for tantalum removal. Although Appellant
contends throughout the Appeal Brief that CMP is a very sensitive process,
which depends on a number of variable such that there would be no
reasonable expectation in the Examiner's combination of references for the
recited oxidizers (see Appeal Br. 11-12), we are of the view that the
preponderance of the evidence weighs in favor of the Examiner's position.
That is, Appellant's arguments speak to the number of options
available to the skilled artisan in formulating and adjusting material removal
rates depending on the substrates to be polished, which does not in itself
translate to a lack of a reasonable expectation of success in combining the
prior art, and in view of the prior art teachings regarding periodate and
persulfate oxidizers discussed above, certainly does not amount to an
"arbitrary combination of components" as asserted by Appellant. (Appeal
Br. 12.)
We are also not persuaded by Appellant's argument that Small's
preferred embodiment that only one oxidizer is present in the CMP
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composition teaches away from the Examiner's combination (Appeal Br. 4--
5), because, as discussed above, Small clearly discloses embodiments
including combinations of oxidizers. A reference is not limited to the
disclosed preferred embodiments. See Merck & Co., Inc. v. Biocraft Labs.,
Inc., 874 F.2d 804, (Fed. Cir.).
We are not persuaded by Appellant's argument that Grumbine does
not teach an increase in tantalum removal rate by including persulfate
oxidizing agent, but rather teaches away from the use of persulfate. (Appeal
Br. 9-10.) Appellant focuses on the comparison of compositions containing
a single oxidizing agent in polishing system 4A versus those containing
combinations of oxidizing agents in Table 4 of Grumbine. (Id.; Grumbine,
Table 4.) However, as pointed out by the Examiner, Grumbine discloses
compositions including no oxidizing agent (polishing system 4I), which has
a lower tantalum removal rate compared to a composition containing a
combination of oxidizing agents including persulfate (polishing system 4C).
(Ans. 7-8; Grumbine Table 4, see also polishing system 4F including a
single oxidizing agent with a lower tantalum removal rate than polishing
system 4C.)
Although we agree with Appellant that Grumbine discloses periodate
as a source of iodine, rather than a periodate oxidizing agent (Appeal Br. 8-
9; Grumbine, ,r 21 ), as the Examiner points out, Grumbine is not relied upon
for the specific structure or combination as recited in the claims, but to show
that persulfate oxidizer can be added to adjust the polishing rate of tantalum.
(Ans. 7.) Such a finding is also supported by Wang, which discloses the use
of persulfate oxidizers in tantalum selective polishing compositions. (Final
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Act. 5 (citing Wang, col. 3, 11. 32-34, 43--47, 57----67; col. 4, 11. 5-10, 32-37,
and 58----67).)
Accordingly, we affirm the Examiner's rejection of claims 19, 21, 22,
and 24--39.
DECISION
We affirm the Examiner's decision rejecting claims 19, 21, 22, and
24--39.
TIME PERIOD
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 ).
AFFIRMED
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