Lone Star Silicon Innovations v. Iancu

Case: 19-1669 Document: 55 Page: 1 Filed: 03/25/2020
NOTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
LONE STAR SILICON INNOVATIONS LLC,
Appellant
v.
ANDREI IANCU, UNDER SECRETARY OF
COMMERCE FOR INTELLECTUAL PROPERTY
AND DIRECTOR OF THE UNITED STATES
PATENT AND TRADEMARK OFFICE,
Intervenor
______________________
2019-1669
______________________
Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. IPR2017-
01566.
______________________
Decided: March 25, 2020
______________________
TIMOTHY P. MALONEY, Fitch, Even, Tabin & Flannery,
Chicago, IL, argued for appellant. Also represented by
NICHOLAS T. PETERS, DAVID ALLEN GOSSE.
DANIEL KAZHDAN, Office of the Solicitor, United States
Patent and Trademark Office, Alexandria, VA, argued for
intervenor. Also represented by MAI-TRANG DUC DANG,
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2 LONE STAR SILICON INNOVATIONS v. IANCU
THOMAS W. KRAUSE, BRIAN RACILLA, FARHEENA YASMEEN
RASHEED, MEREDITH HOPE SCHOENFELD.
______________________
Before LOURIE, SCHALL, and CHEN, Circuit Judges.
LOURIE, Circuit Judge
Lone Star Silicon Innovations LLC (“Lone Star”) ap-
peals from the final written decision of the Patent Trial and
Appeal Board (“Board”) holding claims 2 and 7 of U.S. Pa-
tent 6,388,330 (the “’330 patent”) unpatentable as obvious.
For the reasons described below, we affirm.
BACKGROUND
Lone Star is the owner of the ’330 patent, which is di-
rected to semiconductor etch stop layers with low dielectric
constants. An etch stop layer is made of material that is
resistant to the process used to etch other layers of a semi-
conductor device and is deposited between two other layers
to allow those layers to be etched separately. The invention
of the ’330 patent reduces capacitive coupling between lay-
ers of metal interconnects by reducing the dielectric con-
stant of the etch stop layers to below 5.5, in contrast to the
prior art dielectric constants of 7.5 or higher.
Independent claims 1 and 6, which are not at issue in
this appeal, are directed to integrated circuits comprising
an “etch stop layer of silicon nitride . . . having a dielectric
constant below 5.5.” ’330 patent col. 6 ll. 62–64, col. 7 ll.
22–24, col. 8 ll. 4–6. Dependent claims 2 and 7, which are
at issue in this appeal, are directed to the integrated cir-
cuits of claims 1 and 6 respectively, wherein the silicon ni-
tride etch stop layer is a “multilayer structure.” Id. col. 7
ll. 3–4, col. 8 ll. 12–13.
Micron Technology, Inc. (“Micron”) petitioned for inter
partes review of claims 1, 2, 5, 6, 7, and 10. Micron asserted
a single ground in its petition, namely, that the challenged
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LONE STAR SILICON INNOVATIONS v. IANCU 3
claims were obvious over Watatani 1 in view of Tanaka. 2
The petition stated: “The Ground is explained below and is
supported by the Declaration of Dr. Richard B. Fair.”
J.A. 70.
Within that single ground, Micron asserted two sepa-
rate theories regarding the prior art’s teaching of the “mul-
tilayer structure” limitation in claims 2 and 7. In its first
theory, Micron contended that “Watatani expressly de-
scribes an etch stop layer that includes ‘three or more lay-
ers’ of silicon nitride.” J.A. 105 (citing Watatani col. 7 ll.
54–55). In its second theory, Micron contended that “[s]uch
multilayer silicon nitride layers were well known in the
prior art,” and Micron supported this second theory with
declaration testimony from its expert as well as prior art
references Watatani, SST 1987, 3 and Wang. 4 See J.A. 105–
07; see also J.A. 81–82 (“It Was Well Known In The Prior
Art To Form Multilayer Silicon Nitride Etch Stop Films”).
The Board instituted review of the challenged claims.
J.A. 209. For the “multilayer structure” of claims 2 and 7,
the Board rejected Micron’s first theory, i.e., the theory
based on the description in Watatani. J.A. 224 (“On this
record, we agree with Patent Owner that Watatani does
not describe an etch stop layer that includes three or more
layers of silicon nitride.”). But the Board expressly
1 U.S. Patent 6,153,511.
2 Masayuki Tanaka et al., Low-k SiN Film for Cu In-
terconnects Integration Fabricated by Ultra Low Tempera-
ture Thermal CVD, in 1999 SYMPOSIUM ON VLSI
TECHNOLOGY, DIGEST OF TECHNICAL PAPERS, 47–48 (Bus.
Center for Acad. Societies Japan, 1999).
3 Novellus Sys., Continuous Process CVD System, 30
SOLID STATE TECH., no. 10, Oct. 1987, at 49–50.
4 U.S. Patent 6,017,791.
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4 LONE STAR SILICON INNOVATIONS v. IANCU
acknowledged that Micron had asserted a second inde-
pendent theory for the “multilayer structure” limitation:
Petitioner’s contentions regarding claims 2 and 7
are not, however, based solely on Watatani’s disclo-
sure of multilayer etch stops. Petitioner also con-
tends that “multilayer silicon nitride layers were
well known in the prior art.”
J.A. 225. The Board found that Micron’s evidence—includ-
ing the teachings of SST 1987 and Wang—was “sufficient
to support its contention that multilayer silicon nitride lay-
ers were known in the art.” J.A. 226.
Lone Star filed a request for rehearing, arguing that
the Board exceeded its authority by instituting review of
claims 2 and 7 “based on a new ground not asserted in the
Petition.” J.A. 241. The Board denied Lone Star’s request,
finding that the institution decision relied on additional
prior art references “in the same way” that Micron’s peti-
tion did, namely, “as evidence of the knowledge of a person
of ordinary skill in the art.” J.A. 258. The Board noted
that Lone Star “cites no authority for the proposition that
a reference relied upon to show that a claim limitation is
within the knowledge of a [person of ordinary skill in the
art] must be expressly included in the list of references that
denominate the ground.” J.A. 259; see J.A. 258 (“Our reli-
ance on SST 1987, however, does not transform the insti-
tuted ground into a ‘new ground,’ as argued by Patent
Owner.”).
In its patent owner response, Lone Star again raised
its contention that the Board had exceeded its authority
and also addressed the merits of the obviousness challenge.
Micron argued in reply that the instituted ground based on
Watatani, Tanaka, and the knowledge of a person of ordi-
nary skill had been asserted in the petition. J.A. 378–80.
Micron also submitted a second declaration from its expert
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LONE STAR SILICON INNOVATIONS v. IANCU 5
declarant, Dr. Fair, who cited yet another reference, Yota, 5
to support his opinion that that multilayer silicon nitride
films were well-known in the art. See J.A. 890–94.
Lone Star believed that portions of Micron’s reply im-
properly relied on new evidence, particularly those por-
tions that relied on Dr. Fair’s citations to additional
exhibits, such as Yota, that were not previously submitted
with Micron’s petition. See J.A. 1483–85. The parties
jointly requested permission from the Board to submit ad-
ditional briefing, which the Board allowed. Id. Lone Star
thus had the opportunity to submit a sur-reply in which it
addressed Dr. Fair’s second declaration, including his reli-
ance on Yota. See J.A. 397–99.
In its final written decision, the Board held all of the
challenged claims, including claims 2 and 7, obvious over
Watatani in view of Tanaka. J.A. 2. The Board again re-
jected Lone Star’s argument that the Board had exceeded
its authority and again emphasized that its institution de-
cision and final written decision properly relied on addi-
tional references like SST 1987 “in the same way as it was
relied upon in the Petition: as evidence that multilayer sil-
icon nitride layers were known in the prior art.” J.A. 42.
On the merits, the Board held that Micron proved by a pre-
ponderance of the evidence that a person of ordinary skill
in the art would have been motivated to use a multilayer
silicon nitride structure when forming an etch stop layer
and would have had a reasonable expectation of success in
achieving the subject matter of claims 2 and 7. J.A. 38–39.
5 Jiro Yota et al., Comparison between HDP CVD
and PECVD Silicon Nitride for Advanced Interconnect Ap-
plications, in PROC. OF THE IEEE 2000 INT’L INTERCONNECT
TECH. CONFERENCE, 76–78 (IEEE Electron Devices Soc’y,
2000).
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6 LONE STAR SILICON INNOVATIONS v. IANCU
Lone Star appealed the Board’s final written decision
only with respect to claims 2 and 7. Micron declined to par-
ticipate in the appeal because it had already reached a set-
tlement with Lone Star. The Director of the United States
Patent and Trademark Office (“Director”) intervened pur-
suant to 35 U.S.C. § 143. We have jurisdiction under
28 U.S.C. § 1295(a)(4)(A).
DISCUSSION
Our review of a Board decision is limited. In re Baxter
Int’l, Inc., 678 F.3d 1357, 1361 (Fed. Cir. 2012). We review
the Board’s legal determinations de novo, In re Elsner, 381
F.3d 1125, 1127 (Fed. Cir. 2004), but we review the Board’s
factual findings underlying those determinations for sub-
stantial evidence, In re Gartside, 203 F.3d 1305, 1316 (Fed.
Cir. 2000). A finding is supported by substantial evidence
if a reasonable mind might accept the evidence as adequate
to support the finding. Consol. Edison Co. v. NLRB, 305
U.S. 197, 229 (1938). “Where there is adequate and sub-
stantial evidence to support either of two contrary findings
of fact, the one chosen by the board is binding on the court
regardless of how we might have decided the issue if it had
been raised de novo.” Mishara Constr. Co. v. United States,
230 Ct. Cl. 1008, 1009 (1982) (citing Koppers Co. v. United
States, 186 Ct. Cl. 142, 151 (1968), and Nat’l Concrete &
Found. Co. v. United States, 170 Ct. Cl. 470, 478 (1965)).
Lone Star raises two challenges on appeal. First, Lone
Star contends that the Board exceeded its authority when
it reviewed claims 2 and 7 and held them unpatentable
based on a ground of obviousness that was not asserted in
Micron’s petition for inter partes review. Second, Lone
Star contends that the Board’s obviousness conclusion for
claims 2 and 7 is not supported by substantial evidence.
We address Lone Star’s challenges in turn.
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LONE STAR SILICON INNOVATIONS v. IANCU 7
I
Lone Star argues that the petition set forth a single
ground of obviousness based solely on the combination of
Watatani and Tanaka, but the Board held the claims un-
patentable based on an unasserted ground that included a
combination of those two references with at least three ad-
ditional references—SST 1987, Wang, and Yota. According
to Lone Star, the Board exceeded its authority, as set forth
in 37 C.F.R. § 42.108(a), to authorize review to proceed on
“all or some of the grounds of unpatentability asserted for
each claim.” Appellant Br. 37 (quoting and adding empha-
sis to the regulation).
The Director responds that Lone Star is attempting to
challenge the Board’s institution decision, which is a non-
appealable issue pursuant to 35 U.S.C. § 314(d). The Di-
rector further argues that, even to the extent that Lone
Star’s challenge is appealable, the Board did not abuse its
discretion or exceed its authority in this case.
We agree with the Director that Lone Star’s challenge
is directed to the Board’s institution decision, which is not
appealable. The relevant statutory language is the “No Ap-
peal” clause in Section 314(d):
(d) No Appeal.—The determination by the Direc-
tor whether to institute an inter partes review un-
der this section shall be final and nonappealable.
In Cuozzo Speed Techs., LLC v. Lee, 136 S. Ct. 2131, 2141
(2016) (“Cuozzo III”), the Supreme Court held that “[t]he
text of the ‘No Appeal’ provision, along with its place in the
overall statutory scheme, its role alongside the Adminis-
trative Procedure Act, the prior interpretation of similar
patent statutes, and Congress’ purpose in crafting inter
partes review, all point in favor of precluding review of the
Patent Office’s institution decisions.”
We recently addressed a challenge similar to the one
presented here. See Koninklijke Philips N.V. v. Google
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8 LONE STAR SILICON INNOVATIONS v. IANCU
LLC, 948 F.3d 1330 (Fed. Cir. 2020). In that case, the pe-
tition presented a single obviousness ground based on the
SMIL reference but also relied on the Hua reference as ev-
idence of what was known in the art. Id. at 1333–34. Alt-
hough the petition asserted only one obviousness ground,
the Board instituted review on two obviousness grounds—
(1) SMIL in view of Hua and (2) SMIL “in light of the gen-
eral knowledge of the skilled artisan.” Id. at 1334. Regard-
ing the first instituted ground, we concluded that it was
error for the Board to institute review based on a ground of
obviousness over SMIL and Hua because that ground was
not presented in the petition. Id. at 1337. But regarding
the second instituted ground, we found no error in the
Board’s decision to institute review based on obviousness
over SMIL in view of the knowledge of a person of ordinary
skill. Id. at 1338. Notably, the evidence presented to sup-
port the knowledge of a person of skill relied in part on
other references, including Hua.
Here, like the second instituted ground in Koninklijke
Philips, the Board instituted inter partes review based on
the ground of obviousness that was presented in Micron’s
petition—Watatani in view of Tanaka. The petition undis-
putedly asserted only one obviousness ground. The Board
was not, however, obligated to “ignore the skilled artisan’s
knowledge when determining whether it would have been
obvious to modify the prior art.” Id. at 1337. Indeed, the
statutory definition of obviousness expressly depends on
what would have been known to a person having ordinary
skill in the art. 35 U.S.C. § 103.
Lone Star focuses entirely on the listed references.
Lone Star insists that the instituted ground was not actu-
ally presented in the petition because it relies on additional
references beyond Watatani and Tanaka that were not pre-
sented in the petition and the Board lacked authority to
sua sponte add its own ground of unpatentability. Lone
Star argues that the mere fact that the Board failed to ex-
plicitly acknowledge this as a “new ground” is insufficient
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LONE STAR SILICON INNOVATIONS v. IANCU 9
to distinguish this case from the first instituted ground in
Koninklijke Philips, which we found to be instituted in er-
ror. 948 F.3d at 1337. But here, the Board repeatedly
made clear that the instituted ground was based on Wa-
tatani and Tanaka, and that the additional references were
being relied on exclusively for their teachings about what
was well-known in the art. J.A. 225; see also J.A. 42, 258.
And the Board only did so after it expressly interpreted the
petition to have presented that argument. E.g. J.A. 225
(quoting “[p]etitioner’s contention[] . . . that ‘multilayer sil-
icon nitride layers were well known in the prior art.’” (em-
phasis added)); J.A. 226 (“Petitioner’s evidence is sufficient
to support its contention . . . .”). Under Section 314(d), the
Board’s decision to institute review based on its interpre-
tation of the petition is not appealable. See Cuozzo III, 136
S. Ct. at 2139 (holding that the Board’s interpretation of
the petition to have implicitly presented a challenge was
unreviewable).
Lone Star attempts to avoid the “No Appeal” clause by
arguing that its challenge in this case is not to the Board’s
institution decision, but rather to the scope of the Board’s
statutory and regulatory authority throughout the pro-
ceeding, which is reviewable. Lone Star relies heavily on
the Supreme Court’s acknowledgment that the petition is
“the centerpiece of the proceeding both before and after in-
stitution.” SAS Inst., Inc. v. Iancu, 138 S. Ct. 1348, 1358
(2018). Lone Star argues that the “No Appeal” clause in
Section 314(d) pertains only to the “preliminary patenta-
bility [decision]” based on the “patentability merits of par-
ticular claims,” and is thus inapplicable in this case. See
Reply Br. 6 (quoting Wi-Fi One, LLC v. Broadcom Corp.,
878 F.3d 1364, 1372 (Fed. Cir. 2018) (en banc)). According
to Lone Star, the controlling authority in this case is 37
C.F.R. § 42.108, which allows the Board to institute review
“on all or some of the grounds of unpatentability asserted.”
Lone Star also argues that 35 U.S.C. § 311(b) limits the
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10 LONE STAR SILICON INNOVATIONS v. IANCU
scope of the Board’s authority to a ground on which a peti-
tioner asks for review.
We disagree with Lone Star’s characterization of both
its challenge and the Board’s institution decision. In
Cuozzo III, the Supreme Court held that the “No Appeal”
clause applies to attacks that are “closely tied” to the
Board’s “decision to initiate inter partes review.” 136 S. Ct.
at 2141. We find that this is such a case. In order to grant
the relief that Lone Star requests, we would have to un-
wind the Board’s institution decision and compare it to the
particular language used in Micron’s petition regarding the
“multilayer structure” limitation, which is precisely the
kind of analysis the Supreme Court cautioned against. Id.
at 2139. In essence, Lone Star’s argument that a specific
theory was not within “the grounds of unpatentability as-
serted” under 37 C.F.R. § 42.108 “is little more than a chal-
lenge to the Patent Office’s conclusion, under § 314(a), that
the ‘information presented in the petition’ warranted re-
view.” Id. at 2142.
In an attempt to distinguish Cuozzo III, Lone Star
points to a number of cases in which this court has re-
viewed institution-stage issues. But in each such case the
reviewable issue was not closely tied to substantive patent-
ability requirements. See Arista Networks, Inc. v. Cisco
Sys., Inc., 908 F.3d 792, 799 (Fed. Cir. 2018) (reviewing as-
signor estoppel); Wi-Fi One, 878 F.3d 1364, 1374 (review-
ing time bar); see generally Applications in Internet Time,
LLC v. RPX Corp., 897 F.3d 1336 (Fed. Cir. 2018) (review-
ing the real party in interest requirement). And while the
Supreme Court itself acknowledged that the “No Appeal”
clause does not extend to appealable constitutional or stat-
utory violations, Cuozzo III, 136 S. Ct. at 2141–42, that
acknowledgement is not applicable here, where Lone Star’s
challenge is to the evidentiary basis underpinning the
Board’s interpretation of the petition in its institution de-
cision.
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LONE STAR SILICON INNOVATIONS v. IANCU 11
We also note that that this court has entertained chal-
lenges to the Board for exceeding its authority in violation
of the Administrative Procedure Act (“APA”) by, for exam-
ple, failing to give “notice of and a fair opportunity to meet
the grounds of rejection.” In re NuVasive, Inc., 841 F.3d
966, 971 (Fed. Cir. 2016) (quoting Belden Inc. v. Berk-Tek
LLC, 805 F.3d 1064, 1080 (Fed. Cir. 2015)). But, im-
portantly, Lone Star has not raised such a challenge under
the APA in this case. Indeed, the crux of Lone Star’s argu-
ment is that the Board exceeded its authority notwith-
standing the undisputed fact that Lone Star did have
notice of the full scope of the inter partes review and an
adequate opportunity to respond in its patent owner re-
sponse and its sur-reply. In the context of challenges under
the APA, we have found that the Board is within its au-
thority to institute review and consider even arguments
that were not asserted in the petition “after giving [the pa-
tent owner] a full opportunity to submit additional evi-
dence and arguments on that point.” NuVasive, 841 F.3d
at 975 (citing In re Kumar, 418 F.3d 1361, 1367–69 (Fed.
Cir. 2005)). All the more so here, where the Board put Lone
Star on notice of its finding that the “multilayer structure”
theory was presented in the petition, there is nothing in the
patent statute or the regulations that limits the Board’s
authority to include that theory within the scope of its re-
view. 6
6 Although not cited in the petition, Yota was not
needed for the petition to establish, on the basis of SST
1987 and Wang, that multilayer silicon nitride structures
were well known. To the extent that the Board relied on
Yota to rebut specific arguments made by Lone Star
against reasonable expectation of success, the Board was
within its authority to do so where Lone Star was given
ample opportunity to respond.
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12 LONE STAR SILICON INNOVATIONS v. IANCU
At bottom, the Board interpreted the petition to have
presented a specific theory for the “multilayer structure”
limitation. The Board instituted an inter partes review
that includes that theory. Lone Star asks us to review that
institution decision. Under the “No Appeal” clause, as in-
terpreted by the Supreme Court in Cuozzo III, that decision
is not reviewable.
II
We turn now to Lone Star’s challenge on the merits of
the Board’s obviousness conclusion for claims 2 and 7. Ob-
viousness is a question of law based on underlying facts,
including the scope and content of the prior art, differences
between the prior art and the claims at issue, the level of
ordinary skill, and relevant evidence of secondary consid-
erations. Graham v. John Deere Co., 383 U.S. 1, 17–18
(1966). Whether a skilled artisan would have been moti-
vated to combine prior art references is also a question of
fact. Wyers v. Master Lock Co., 616 F.3d 1231, 1238–39
(Fed. Cir. 2010).
Lone Star challenges a number of the facts underlying
the Board’s obviousness conclusion. Lone Star contends
that, even accepting that a multilayer structure of silicon
nitride was well-known in the art, the record is devoid of
evidence that such a multilayer structure was known to be
used as an etch stop layer, which is what claims 2 and 7
actually require. Lone Star also challenges the Board’s
conclusions regarding motivation to combine and reasona-
ble expectation of success. Lone Star argues that the two
alleged motivations to use a multilayer structure—layer
uniformity and avoiding pinholes—are divorced from the
overall context of the claims, which require that the etch
stop layer have a dielectric constant below 5.5. And Lone
Star argues that the evidence in the record demonstrates
that a person of skill would have expected a multilayer
structure to increase the dielectric constant of the etch stop
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LONE STAR SILICON INNOVATIONS v. IANCU 13
layer, which is the opposite of the claimed invention di-
rected to lower dielectric constants.
The Director responds that the multilayer structure
limitation of claims 2 and 7 adds no patentable significance
to the obvious integrated circuit of claims 1 and 6. Said
differently, the Director argues that claims 2 and 7 are di-
rected to nothing more than starting with an obvious inte-
grated circuit and adding a well-known multilayer
structure that has well-established benefits for integrated
circuits. The Director further argues that Lone Star’s mo-
tivation to combine argument is contrary to law, and that
substantial evidence from both parties’ experts and multi-
ple prior art references supports the Board’s findings re-
garding reasonable expectation of success.
We agree with the Director. The Supreme Court has
made clear that “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 appli-
cation is beyond his or her skill.” KSR Int’l Co. v. Teleflex
Inc., 550 U.S. 398, 417 (2007). For purposes of this appeal,
it is not disputed that multilayer structures were known to
improve integrated circuits by improving layer uniformity
and decreasing pinholes. And the record contains substan-
tial evidence that using the multilayer structure of silicon
nitride recited in claims 2 and 7 would improve the etch
stop layers in the integrated circuits of claims 1 and 6 in
the same way. Thus, the multilayer structure does not ren-
der nonobvious the otherwise obvious integrated circuits of
claims 1 and 6.
Furthermore, regarding a motivation to combine, we
reject Lone Star’s contention that the known advantages
that would have motivated a person of skill to use multi-
layer structures must be shown to directly impact the
claimed lower dielectric constant. On the contrary, the law
is clear that “the motivation to modify a prior art reference
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14 LONE STAR SILICON INNOVATIONS v. IANCU
to arrive at the claimed invention need not be the same mo-
tivation that the patentee had.” Monsanto Tech. LLC v.
E.I. DuPont de Nemours & Co., 878 F.3d 1336, 1347 (Fed.
Cir. 2018) (citation omitted, emphasis added). Here, there
is substantial evidence that a person of skill would have
been motivated to use a multilayer structure of silicon ni-
tride as an etch stop layer to improve layer uniformity and
avoid pinholes. And, having been motivated to use a mul-
tilayer structure, the person of skill would have thus ar-
rived at the claimed invention of claims 2 and 7.
Finally, regarding the reasonable expectation of suc-
cessfully achieving a low dielectric constant with a multi-
layer structure, the Board relied on the testimony of both
parties’ expert witnesses regarding the relationship be-
tween density and dielectric constants when stacking mul-
tiple thin layers to achieve thickness. J.A. 41–42 (citing
both Dr. Fair and Dr. Bottoms). And simply put, the
Tanaka prior art reference teaches a silicon nitride layer
with a dielectric constant that is below 5.5 as required by
the claims, see J.A. 41, and Micron’s expert, Dr. Fair,
pointed to multiple references to support his opinion that
the low dielectric constant could be maintained using a
multilayer structure. J.A. 893–94. Lone Star challenged
Dr. Fair’s opinions below with the same factual arguments
it now raises on appeal, but the Board rejected Lone Star’s
challenges based on the teachings of the prior art refer-
ences, the background of the ’330 patent itself, and incon-
sistencies within Lone Star’s positions. J.A. 47–48. We are
not in a position to second-guess the Board’s evaluation of
expert witnesses’ credibility or its reconciliation of per-
ceived inconsistencies in their testimony. Yorkey v. Diab,
601 F.3d 1279, 1284 (Fed. Cir. 2010) (“We defer to the
Board’s findings concerning the credibility of expert wit-
nesses.” (citing Velander v. Garner, 348 F.3d 1359, 1371
(Fed. Cir. 2003))). On this record, the Board’s finding that
a person of skill would have had a reasonable expectation
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LONE STAR SILICON INNOVATIONS v. IANCU 15
of successfully achieving the invention of claims 2 and 7 is
supported by substantial evidence.
CONCLUSION
We have considered Lone Star’s remaining arguments,
but we find them to be unpersuasive. Accordingly, the de-
cision of the Board holding unpatentable claims 2 and 7 of
the ’330 patent is affirmed.
AFFIRMED