Document ID: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-ca13-19-01669/USCOURTS-ca13-19-01669-0/pdf.json

Parties Involved:
Andrei Iancu
Intervenor
Lone Star Silicon Innovations LLC
Appellant
Micron Technology, Inc.
Appellee

Document Text:

NOTE: This disposition is nonprecedential.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”) appeals from the final written decision of the Patent Trial and 

Appeal Board (“Board”) holding claims 2 and 7 of U.S. Patent 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 directed 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 semiconductor 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 layers of metal interconnects by reducing the dielectric constant 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 circuits of claims 1 and 6 respectively, wherein the silicon nitride 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 Watatani1 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 separate theories regarding the prior art’s teaching of the “multilayer structure” limitation in claims 2 and 7. In its first 

theory, Micron contended that “Watatani expressly describes an etch stop layer that includes ‘three or more layers’ 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 Interconnects Integration Fabricated by Ultra Low Temperature 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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acknowledged that Micron had asserted a second independent theory for the “multilayer structure” limitation:

Petitioner’s contentions regarding claims 2 and 7 

are not, however, based solely on Watatani’s disclosure of multilayer etch stops. Petitioner also contends that “multilayer silicon nitride layers were 

well known in the prior art.”

J.A. 225. The Board found that Micron’s evidence—including the teachings of SST 1987 and Wang—was “sufficient 

to support its contention that multilayer silicon nitride layers 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 petition 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 reliance on SST 1987, however, does not transform the instituted 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 ordinary skill had been asserted in the petition. J.A. 378–80. 

Micron also submitted a second declaration from its expert 

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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 improperly relied on new evidence, particularly those portions 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 additional 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 reliance 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 rejected Lone Star’s argument that the Board had exceeded 

its authority and again emphasized that its institution decision and final written decision properly relied on additional references like SST 1987 “in the same way as it was 

relied upon in the Petition: as evidence that multilayer silicon nitride layers were known in the prior art.” J.A. 42. 

On the merits, the Board held that Micron proved by a preponderance 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 Applications, in PROC. OF THE IEEE 2000 INT’L INTERCONNECT 

TECH. CONFERENCE, 76–78 (IEEE Electron Devices Soc’y, 

2000).

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Lone Star appealed the Board’s final written decision 

only with respect to claims 2 and 7. Micron declined to participate in the appeal because it had already reached a settlement with Lone Star. The Director of the United States 

Patent and Trademark Office (“Director”) intervened pursuant 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 substantial 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 substantial 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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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 unpatentable based on an unasserted ground that included a 

combination of those two references with at least three additional 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 emphasis to the regulation).

The Director responds that Lone Star is attempting to 

challenge the Board’s institution decision, which is a nonappealable issue pursuant to 35 U.S.C. § 314(d). The Director 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 Appeal” clause in Section 314(d):

(d) No Appeal.—The determination by the Director whether to institute an inter partes review under 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 Administrative 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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LLC, 948 F.3d 1330 (Fed. Cir. 2020). In that case, the petition presented a single obviousness ground based on the 

SMIL reference but also relied on the Hua reference as evidence of what was known in the art. Id. at 1333–34. Although 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 general knowledge of the skilled artisan.” Id. at 1334. Regarding 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 support 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 undisputedly 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 actually presented in the petition because it relies on additional 

references beyond Watatani and Tanaka that were not presented 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 explicitly acknowledge this as a “new ground” is insufficient 

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to distinguish this case from the first instituted ground in 

Koninklijke Philips, which we found to be instituted in error. 948 F.3d at 1337. But here, the Board repeatedly 

made clear that the instituted ground was based on Watatani 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 silicon nitride layers were well known in the prior art.’” (emphasis 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 interpretation 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 proceeding, 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 institution.” 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 patentability [decision]” based on the “patentability merits of particular 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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scope of the Board’s authority to a ground on which a petitioner 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 unwind 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 asserted” under 37 C.F.R. § 42.108 “is little more than a challenge to the Patent Office’s conclusion, under § 314(a), that 

the ‘information presented in the petition’ warranted review.” Id. at 2142.

In an attempt to distinguish Cuozzo III, Lone Star 

points to a number of cases in which this court has reviewed institution-stage issues. But in each such case the 

reviewable issue was not closely tied to substantive patentability requirements. See Arista Networks, Inc. v. Cisco 

Sys., Inc., 908 F.3d 792, 799 (Fed. Cir. 2018) (reviewing assignor estoppel); Wi-Fi One, 878 F.3d 1364, 1374 (reviewing time bar); see generally Applications in Internet Time, 

LLC v. RPX Corp., 897 F.3d 1336 (Fed. Cir. 2018) (reviewing 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 statutory 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 decision.

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We also note that that this court has entertained challenges to the Board for exceeding its authority in violation 

of the Administrative Procedure Act (“APA”) by, for example, 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, importantly, Lone Star has not raised such a challenge under 

the APA in this case. Indeed, the crux of Lone Star’s argument is that the Board exceeded its authority notwithstanding 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 response and its sur-reply. In the context of challenges under 

the APA, we have found that the Board is within its authority to institute review and consider even arguments 

that were not asserted in the petition “after giving [the patent owner] a full opportunity to submit additional evidence 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 review. 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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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 interpreted 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. Obviousness 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 considerations. Graham v. John Deere Co., 383 U.S. 1, 17–18 

(1966). Whether a skilled artisan would have been motivated 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 reasonable 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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layer, which is the opposite of the claimed invention directed 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 directed to nothing more than starting with an obvious integrated circuit and adding a well-known multilayer 

structure that has well-established benefits for integrated 

circuits. The Director further argues that Lone Star’s motivation to combine argument is contrary to law, and that 

substantial evidence from both parties’ experts and multiple prior art references supports the Board’s findings regarding 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 application 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 substantial 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 render 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 multilayer 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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to arrive at the claimed invention need not be the same motivation 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 nitride as an etch stop layer to improve layer uniformity and 

avoid pinholes. And, having been motivated to use a multilayer structure, the person of skill would have thus arrived at the claimed invention of claims 2 and 7.

Finally, regarding the reasonable expectation of successfully achieving a low dielectric constant with a multilayer structure, the Board relied on the testimony of both

parties’ expert witnesses regarding the relationship between density and dielectric constants when stacking multiple 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 references, the background of the ’330 patent itself, and inconsistencies 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 perceived 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 witnesses.” (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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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 decision of the Board holding unpatentable claims 2 and 7 of 

the ’330 patent is affirmed.

AFFIRMED

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