Ex Parte Lin et al

Patent Trial and Appeal Board

Feb 27, 2018

13790850 (P.T.A.B. Feb. 27, 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.
13/790,850 03/08/2013 Bo-Jiun Lin TSM12-0748 7375
43859 7590 03/01/2018
SLATER MATSIL, LLP/TSMC
17950 PRESTON ROAD, SUITE 1000
DALLAS, TX 75252
EXAMINER
NGUYEN, SOPHIA T
ART UNIT PAPER NUMBER
2822
NOTIFICATION DATE DELIVERY MODE
03/01/2018 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):
docketing @ slatermatsil. com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte BO-JIUN LIN, HAI-CHING CHEN, and TIEN-I BAO
Appeal 2016-006741
Application 13/790,850
Technology Center 2800
Before DONNA M. PRAISS, WESLEY B. DERRICK, and
CHRISTOPHER L. OGDEN, Administrative Patent Judges.
OGDEN, Administrative Patent Judge.
DECISION ON APPEAL
Appellant1 appeals under 35 U.S.C. § 134(a) from the Examiner’s
final decision rejecting claims 1—3, 5—9, 12, 13, and 21—26 in the above-
identified application.2 We have authority pursuant to 35 U.S.C. § 6(b). For
substantially the reasons set forth by the Examiner in the Final Action,3 the
1 Appellant is Taiwan Semiconductor Manufacturing Company, LTD., which
according to the Appeal Brief, is the real party in interest. Appeal Brief 1,
Dec. 22, 2015 [hereinafter Appeal Br.].
2 See Appeal Br.; Reply Brief, June 27, 2016 [hereinafter Reply Br.].
3 Final Office Action, Apr. 24, 2015 [hereinafter Final Action],
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Application 13/790,850
Answer,4 and the Advisory Action,5 and additional reasons that we provide
below primarily for emphasis, we affirm.
BACKGROUND
Appellant’s Specification relates to “forming damascene structures in
integrated circuit manufacturing processes.” Spec.611. Figure 6,
reproduced below, illustrates certain aspects of the invention:
110.ESL 100 Carbon contained
Figure 6 depicts a damascene structure at a particular manufacturing stage.
Spec. 112. The structure includes substrate 15, above which there is
dielectric insulating layer 20, and etched into layer 20 is conductive member
30 electrically connecting to an underlying semiconductor device. Id. 113.
On top of layers 20 and 30 is etching stop layer 40. Id. Over etching stop
4 Examiner’s Answer, Apr. 27, 2016 [hereinafter Answer],
5 The Examiner incorporated the Advisory Action by reference into the
Answer. Advisory Action 17, July 14, 2015.
6 Specification, Mar. 8, 2013 [hereinafter Spec.].
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layer 40, there is dielectric insulating layer 50, id. 114, in which is formed
damascene opening 70 (including 70A and 70B), id. 117. Damascene
opening 70, which is filled with a copper conductive layer 90, id. 119, is
lined with diffusion barrier blanket 80 which “prevents copper from
diffusing into surrounding materials such as insulating layer 50,” id. 118
(boldface added). Above insulator 50 and the conductive layer 90 is carbon
containing metal-oxide layer 100, formed by a sol-gel process. Id. 121.
Finally, there is etch stop layer 110 above carbon containing metal-oxide
layer 100. Id. 123.
Representative claim 1 reads as follows:
1. A method for forming an interconnect structure,
comprising:
forming an insulating layer on a substrate;
forming a damascene opening through a thickness portion of
the insulating layer;
forming a diffusion barrier layer to line the damascene opening;
forming a conductive layer overlying the diffusion barrier layer
to fill the damascene opening;
forming a carbon-containing metal oxide layer on the
conductive layer and the insulating layer comprising
using a precursor formed by a sol-gel process, the sol-gel
process comprising:
mixing a metal-oxide source and a carbon source
to form a mixture,
adding water to the mixture,
after adding the water to the mixture, stirring the
water and the mixture, and
after stirring the water and the mixture, adding an
acid to the mixture to form the precursor,
and
forming an etch stop layer over the carbon-containing metal
oxide layer.
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Application 13/790,850
Appeal Br. 55 (emphasis of key limitations added). Independent claim 7
includes substantially similar limitations. Id. at 56—57. Independent claim
25 is similar to claim 1, and includes further details with respect to the sol-
gel process corresponding to the above-emphasized language in claim 1,
which reads as follows:
25. A method for forming a copper damascene, comprising:
... the sol-gel process comprising:
mixing a metal-oxide source and a chelating agent
having a carbon source to form a
homogenous solution, the metal-oxide
source comprising aluminum-sec-butoxide,
the carbon source comprising acetylacetone,
ethylacetoacetate, or a combination thereof,
adding water to the homogenous solution to form a
mixture,
after adding the water, stirring the mixture,
after stirring the mixture, adding nitric acid to the
mixture, and
after adding the nitric acid, aging the mixture for
about 24 hours to form the precursor;
Id. at 58—59.
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Application 13/790,850
The Examiner maintains the following rejections:7
1. Claims 1—3, 5—9, 12, 13, and 21—24 are rejected under
35 U.S.C. § 103(a) as being unpatentable over Yu8 in view of the teachings
of Makino,9 Yoldas,10 Huashi,* 11 and Nanao.12 See Final Action 3—11.
2. Claims 25 and 26 are rejected under 35 U.S.C. § 103(a) as
being unpatentable over Banerji13 in view of the teachings of Makino,
Yoldas, and Nanao. Id. at 12—16.
We summarize these rejections and Appellant’s arguments as follows:
Rejection 1
The Examiner finds that Yu discloses all the limitations of claim 1
except for the recited step of forming the precursor for the carbon-containing
metal oxide layer using a sol-gel process. Final Action 4—5; see also Answer
23. According to the Examiner, Makino discloses a sol-gel process for
making the precursor recited in claim 1, except that Makino does not
explicitly disclose, “after adding the water to the mixture, stirring the water
and the mixture, and after stirring the water and the mixture, adding an acid
7 The Examiner has withdrawn a rejection under 35 U.S.C. § 112, second
paragraph. See Advisory Action 2; see also Answer 2.
8 Yu et al., US 2010/0308463 A1 (published Dec. 9, 2010) [hereinafter Yu].
9 Makino et al., US 2011/0274878 Al (published Nov. 10, 2011) [hereinafter
Makino].
10 Bulent E. Yoldas, Alumina Sol Preparation fromAlkoxides, 54 Ceramic
Bull. 289 (1975) [hereinafter Yoldas].
11 Liu Huashi et al, Chemical Modification of Ethylacetoacetate with ASB in
Aqueous Medium, 24 J. Wuhan U. Tech.-Mater. Sci. Ed. 68 (2009)
[hereinafter Huashi],
12 Nanao et al., US 4,668,299 (issued May 26, 1987) [hereinafter Nanao].
13 Banerji et al., US 7,858,510 B1 (issued Dec. 28, 2010) [hereinafter
Banerji],
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to the mixture to form the precursor.” Final Action 5 (citing Makino ^fl[ 6, 9,
13,38,41,43,49-50).
Nevertheless, the Examiner finds that Makino generally teaches
adding water and acid to the mixture. See Final Action 17 (citing Makino
50-51). In addition, the Examiner finds that Makino teaches an
embodiment in which the solvent is an alcohol (rather than water), and
explicitly teaches adding acid after stirring the solvent with the mixture. Id.
at 5 (citing Makino 1120). The Examiner finds that “it is known in the art
that water is a suitable alternative solvent [to] alcohol in preparing alumina
sol using sol gel method.” Id.14
As additional support for the stirring and acid-adding steps, the
Examiner finds that Yoldas teaches that, in a sol-gel process for forming an
alumina precursor, “an acid is added to a mixture containing water and a
metal-oxide source [aluminum alkoxide] after stirring the mixture containing
water and a metal-oxide source.” Id. (citing Yoldas 289). The Examiner
likewise cites Huashi as teaching a sol-gel process for forming an aluminum
precursor that includes stirring water in the mixture (of metal-oxide source
and carbon source) and then adding diluted nitric acid to the mixture to form
the precursor. Id.
The Examiner determines that a person of ordinary skill in the art
would have been motivated to combine the teachings of Makino, Yoldas, and
Huashi into the disclosure of Yu “for the purpose of providing an alternative
method to form an aluminum oxide-containing precursor layer from a
14 See, e.g., Makino 152 (noting, after discussing hydrolysis in water, “An
organic solvent may be used as the solvent.... Examples of the organic
solvent include monohydric alcohols.”).
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solution.” Id. at 6. In particular, the Examiner determines that “the
alternative method has advantages such that. . . simple and nonexpensive
equipment can be employed, a large film can be prepared, a cheap product
can [be] provided because of high productivity and that a uniform film
having an excellent stoichiometric property can be prepared.” Id. (citing
Makino 1 6; Nanao 2:53—68, 3:1—14, 3:60-68, 4:1—5). The Examiner also
determines that “it would have been obvious to try one of the known
methods with a reasonable expectation of success.” Id.
Rejection 2
The Examiner finds that Banerji discloses all the limitations of claim
25 except for the recited step of forming the precursor for the carbon-
containing metal oxide layer using a sol-gel process. Final Action 12—14;
see also Answer 23. According to the Examiner, Yoldas discloses a sol-gel
process for forming an alumina precursor that includes mixing a metal-oxide
source (aluminum-sec-butoxide) and water, followed by stirring, and then
adding nitric acid and aging for sufficient time to form a precursor. Id. at 14
(citing Yoldas 289).
The Examiner also finds that Makino teaches a similar sol-gel process
that includes mixing the metal oxide source with a chelating agent having a
carbon source from a genus that would include acetylacetone. Id. (citing
Makino ^fl[ 42-44, 48—50). The Examiner then cites Nanao as teaching that
the chelating agent in a similar sol-gel process may specifically include
acetylacetone. Id. (citing Nanao col. 5). The Examiner finds that in view of
the teachings of Yoldas, the 24-hour aging limitation would have been
merely a matter of optimization. See id. at 14—15.
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The Examiner determines that a person of ordinary skill in the art
would have been motivated to combine the teachings of Yoldas, Makino, and
Nanao into the disclosure of Banerji “for the purpose of providing an
alternative method to form an aluminum oxide-containing precursor layer
from a solution.” Id. at 15. In particular, the Examiner determines that “the
alternative method has advantages such that. . . simple and nonexpensive
equipment can be employed, a large film can be prepared, a cheap product
can [be] provided because of high productivity and that a uniform film
having an excellent stoichiometric property can be prepared.” Id. (citing
Nanao 2:53—68, 3:1—14, 3:60-68, 4:1—5). The Examiner also determines
that “Applicant did not invent/modify the sol gel method. Applicant only
applies a known sol gel method. Therefore, it would be obvious to one of
ordinary skill in the art to use any well[-]known material/process step of the
sol gel method in the rejection.” Id.
Summary of Appellant’s Arguments
In the Appeal Brief, Appellant argues the claims as a group within
each rejection. See Appeal Br. 8—53. Therefore, consistent with 37 C.F.R.
§ 41.37(c)(l)(iv), we limit our discussion to independent claims 1 and 25.
Claims 2, 3, 5—9, and 12—13 fall with claim 1, and claim 26 falls with claim
25.
Regarding claims 1 and 25, Appellant argues (1) that the Examiner’s
proposed prior art combination represents a substantial reconstruction and
redesign of the elements disclosed by Yu or Banerji,15 respectively, see
15 In general, Appellant presents separate arguments for each of two
embodiments disclosed by Banerji for forming the carbon-containing metal
oxide layer. See Appeal Br. 36—37. In the “first embodiment,” an
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Appeal Br. 16—20, 38-41; (2) that the Examiner’s proposed prior art
combination removes or changes the principles of operation of Yu and
Banerji, respectively, see id. at 20-24, 38-43; (3) that Yu and Banerji,
respectively, teach away from the proposed art combination, see id. at 24—
28, 43 46; (4) that the Examiner’s modification of Yu or Banerji,
respectively, renders the process inoperable for its intended purpose, see id.
at 28—30, 47—51; and (5) that the Examiner has not provided a prima facie
case, see id. at 30—36, 51—53.
DISCUSSION
The Examiner’s Prima Facie Case of Unpatentability
According to the Supreme Court,
If a person of ordinary skill can implement a predictable varia­
tion, § 103 likely bars its patentability For the same reason, if a
technique has been used to improve one device, and a person of
ordinary skill in the art would recognize that it would improve
similar devices in the same way, using the technique is obvious
unless its actual application is beyond his or her skill.
KSRInt’l Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007). The Examiner’s
determination in rejecting claims 1 and 25 is that persons of ordinary skill in
the art, in view of the cited secondary references, would have recognized
organoaluminum reactant is contacted with the copper surface in a vacuum
to form an aluminum-containing layer, the top portion of this layer is
passivated, and the bottom portion of the layer is allowed to diffuse into the
copper. See id.', Banerji, Fig. 3B. The “second embodiment” is substantially
the same as the first, except that the entire aluminum-containing layer is
modified to form an immobile compound (the metal oxide layer, according
to the Examiner), and there is no diffusion into the copper. See Appeal Br.
37; Banerji, Fig. 3B.
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that they could use a known sol-gel process to obtain advantages over the
vacuum processing deposition step disclosed in Yu or Banerji. See Answer
17, 23; Final Action 5—6, 15.
The Examiner’s rejections establish a prima facie case of
unpatentability, because the rejections include “some articulated reasoning
with some rational underpinning to support the legal conclusion of
obviousness.” In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006). Appellant’s
arguments to the contrary are unpersuasive of reversible error for the reasons
stated by the Examiner. See Answer 19, 22—23; see generally Advisory
Action.
In particular, Appellant’s argument that “Yoldas describes a
completely different process” than Makino, and that “Huashi describes a
different process that arrives at a different result” from Makino or Yoldas,
see Appeal Br. 32; see also id. at 52; Reply Br. 7—8, is unpersuasive of
reversible error in the Examiner’s rejection. The Examiner cites each
secondary reference for its particular teachings with respect to a known,
“conventional sol-gel method for forming carbon contained metal oxide
layer.” Answer 23. “The test for obviousness is not whether the features of a
secondary reference may be bodily incorporated into the structure of the
primary reference .... Rather, the test is what the combined teachings of the
references would have suggested to those of ordinary skill in the art.” In re
Keller, 642 F.2d 413, 425 (CCPA 1981); see also KSR, 550 U.S. at 401
(“[T]he [obviousness] analysis need not seek out precise teachings directed
to the challenged claim’s specific subject matter, for a court can consider the
inferences and creative steps a person of ordinary skill in the art would
employ.”).
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Appellant’s argument that the Examiner failed to consider the
invention as a whole, see Appeal Br. 34—35, 53, is also unpersuasive of
reversible error. The Examiner’s rejection includes an explicit rationale that
addresses every claim limitation and articulates a rational explanation for
why a person of ordinary skill in the art would have been motivated to
substitute the known sol-gel process (with specific details found within the
teachings of Makino, Yoldas, Huashi, and Nanao) for the vacuum process in
either Yu or Banerji. See Final Action 5—6, 15. The Examiner has
established, on this record, a prima facie case of unpatentability that
considers claims 1 and 25 as a whole.
Teaching Away
The Supreme Court has held that “when the prior art teaches away
from combining certain known elements, discovery of a successful means of
combining them is more likely to be nonobvious.” KSR, 550 U.S. at 416.
Consistent with this, the Federal Circuit’s predecessor held in In re Ratti,
270 F.2d 810 (CCPA 1959), that it would not have been obvious to replace a
“cylindrical sheet metal reinforcing member” in a seal with “an annular set
of outwardly biased spring fingers,” because the prior art teaching “points
away from the addition of any spring element.” Id. at 812—13. In particular,
the court held that the substitution “would require a substantial
reconstruction and redesign of the elements shown in [the seal] as well as a
change in the basic principles under which the [seal’s] construction was
designed to operate.” Id. at 813.
Similarly, the Federal Circuit has stated that “[i]n cases involving
mechanical device or apparatus claims, we have held that ‘[i]f references
taken in combination would produce a “seemingly inoperative device,” . . .
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such references teach away from the combination and thus cannot serve as
predicates for a prima facie case of obviousness.’”). In re Urbanski, 809
F.3d 1237, 1234 (Fed. Cir. 2016) (quoting McGinleyv. Franklin Sports, Inc.,
262 F.3d 1339, 1354 (Fed. Cir. 2001)) (citing In re Gordon, 733 F.2d 900,
902 (Fed. Cir. 1984)).
Appellant argues that replacing the metal oxide layer deposition step
in Yu or Banerji16 amounts to a substantial reconstruction and redesign of the
method in Yu or Banerji, because the vacuum processing step represents
each primary reference’s sole contribution to the art. See Appeal Br. 16—20
(citing Ratti), 38—41. This argument is unpersuasive of reversible error.
Unlike the apparatus invention at issue in Ratti, claims 1 and 25 are method
claims. Whereas in Ratti, the prior art combination would have required a
substantial reconstruction and redesign of a prior art apparatus, here the prior
art combination would simply replace a vacuum processing step with a sol-
gel processing step for forming the same structure. We are not persuaded by
Appellants’ contention that because the vacuum steps were the sole
inventive contributions in Yu or Banerji, a skilled artisan would have been
dissuaded from making this substitution.
Appellant also argues that the Examiner’s proposed combination
removes or changes the basic principles upon which either Yu’s or
Banerji’s17 method operates. See id. at 20—24, 38-43. According to
Appellant, Yu’s process operates on the principle of introducing a free
16 This argument relates only to Banerji’s “first embodiment.”
Br. 38.
17 This argument relates only to Banerji’s “first embodiment.”
Br. 42.
See Appeal
See Appeal
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metallic atom (e.g., aluminum) onto a copper surface in order to “pin”
surface copper atoms, control electromigration, and promote adhesion. See
Appeal Br. 21—22. Appellant argues that Banerji’s basic principle of
operation is to cause a dopant to diffuse into copper in order to provide a
protective cap. See id. at 38-43.
Appellant interprets the principle of operation in Yu and Banerji too
narrowly. Yu’s and Banerji’s methods operate on the principle of “forming
layers of material on a partially fabricated integrated circuit.” Yu 2; Banerji
1:23—24. Although Yu and Banerji disclose particular details for the step of
forming a carbon-containing metal oxide layer, the Examiner’s rejection
wholly substitutes this step for a sol-gel process as taught by the secondary
references. Appellant does not persuasively show that a skilled artisan
would have been led away from making this substitution by relying on
teachings in Yu or Banerji made in the context of forming a carbon-
containing metal oxide layer using a vacuum processing step.
Appellant also argues that the Examiner’s rejection does not consider
the references “as a whole,” and if considered as a whole, Yu and Banerji
would have led a skilled artisan on a path that adopts the specific inventive
contributions of Yu and Banerji, and thus diverges from claims 1 and 25.
See id. at 25-28, 43^16, 49; Reply Br. A-6, 8-9, 11, 13, 14, 17, 20, 21.
These arguments are not persuasive of reversible error. While Yu and
Banerji teach benefits and goals applicable to a vacuum process,18 Appellant
18 For example, Appellant argues that with respect to Banerji’s “second
embodiment,” the reference “clearly states that... ‘it is highly important to
provide an oxide-free copper surface to prevent a reaction ... to prevent
aluminum oxide formation’ and that ‘immediate aluminum oxide formation
on copper surface is not desired.’” Appeal Br. 46 (citing Banerji 20:57—65),
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has not directed us to any teaching in either Yu or Banerji that disparages the
use of a sol-gel process, or would discourage a skilled artisan from replacing
the disclosed vacuum process with a sol-gel process.
Finally, Appellant argues that the prior art combination in the
Examiner’s rejections would render Yu and Banerji19 inoperable for its
intended purpose. See Appeal Br. 28—30, 47—51. Appellant argues that “the
intended purpose of Yu is the formation of an adhesion layer to achieve
increased adhesion and electromigration performance,” and that “the
intended purpose of Banerji’s first embodiment is the formation of a
protective cap for improved electromigration performance.” Id. at 28, 47.
Appellant regards “the reaction of a free metal atom M2 with copper oxide”
and “the controlled introduction of dopants in copper,” respectively, as
necessary parts of Yu’s and Banerji’s intended purposes. Id. at 28, 47.
Appellant interprets the intended purposes of Yu and Banerji’s
methods too narrowly. As applied in the Examiner’s rejections, Yu and
Banerji teach processes for forming Damascene interconnect structures on a
semiconductor. Yu^flf 50-51; Figs. 1A— IE; Banerji 8:31—54, 20:48—51, Figs
1 A—IE, 3B. Appellant has not directed us to persuasive evidence in this
appeal record that a person of ordinary skill in the art would have
understood, in light of the teachings of Yu or Banerji, that substituting a sol-
gel process for the disclosed vacuum process would have rendered the
process inoperable for forming a Damascene interconnect structure.
Appellant does not point to any evidence in this appeal record that a skilled
artisan would have considered this guidance applicable in the context of a
sol-gel process.
19 This argument only relates to Banerji’s “first embodiment.” See Appeal
Br. 47.
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For the above reasons and those stated by the Examiner, we affirm the
Examiner’s rejection of claims 1—3, 5—9, 12, 13, and 21—26.
DECISION
The Examiner’s decision is affirmed.
No time period for taking any subsequent action in connection with
this appeal maybe extended. See 37 C.F.R. § 1.136(a)(l)(iv) (2016).
AFFIRMED
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