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Lone Star Silicon Innovations LLC v. Iancu

United States Court of Appeals for the Federal Circuit

March 25, 2020, Decided

2019-1669

Opinion

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 [*2]  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 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 [*3]  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").

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2020 U.S. App. LEXIS 9342 *; 2020 U.S.P.Q.2D (BNA) 10239

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

Notice: THIS DECISION WAS ISSUED AS UNPUBLISHED OR NONPRECEDENTIAL AND MAY NOT BE CITED AS PRECEDENT. PLEASE REFER TO FEDERAL RULES OF APPELLATE PROCEDURE RULE 32.1 GOVERNING THE CITATION TO UNPUBLISHED OPINIONS.

Subsequent History: Related proceeding at Nanya Tech. Corp. v. Lone Star Silicon Innovations, LLC, 2020 U.S. App. LEXIS 9647 (Fed. Cir., Mar. 27, 2020)

Prior History:  [*1] Appeal from the United States Patent and Trademark Office, Patent Trial and Appeal Board in No. IPR2017-01566.

Disposition: Affirmed.

CORE TERMS

multilayer, layers, skill, silicon, etch, prior art, nitride, Patent, instituted, references, argues, dielectric constant, integrated circuits, inter partes, unpatentability, substantial evidence, challenges, exceeded, ordinary person, motivation, reasonable expectation, declaration, invention, teachings, grounds

Patent Law, Jurisdiction & Review, Standards of Review, De Novo Review, Substantial Evidence, US Patent & Trademark Office Proceedings, Appeals, Nonobviousness, Administrative Law, Judicial Review, Reviewability, Business & Corporate Compliance, Patent Law, US Patent & Trademark Office Proceedings, Nonobviousness, Evidence, Fact & Law Issues, Elements & Tests, Ordinary Skill Standard, Prior Art, Standards of Review