Samsung Electronics Co Ltd v. Acorn Semi LLC

1. Case Identification

• Case #: IPR2020-[Unassigned]
• Patent #: 10,090,395
• Filed: June 29, 2020
• Petitioner(s): Samsung Electronics Co., Ltd.
• Patent Owner(s): Acorn Semi, LLC
• Challenged Claims: 1-6, 8-12, and 14-16

2. Patent Overview

• Title: METHOD FOR DEPINNING THE FERMI LEVEL OF A SEMICONDUCTOR AT AN ELECTRICAL JUNCTION AND DEVICES INCORPORATING SUCH JUNCTIONS
• Brief Description: The ’395 patent describes methods and devices for creating improved metal-semiconductor electrical junctions. The invention involves placing a specific interface layer, comprising both a metal oxide and a semiconductor oxide, between the metal contact and the semiconductor region to "depin" the Fermi level, thereby controlling the junction's electrical properties and reducing contact resistance.

3. Grounds for Unpatentability

Ground 1: Anticipation over Grupp - Claims 1-6, 8-12, and 14-16 are anticipated by Grupp under 35 U.S.C. §102.

• Prior Art Relied Upon: Grupp (Patent 7,176,483)
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner’s argument hinges on establishing that Grupp is valid prior art. Petitioner contended that the challenged claims are not entitled to their purported August 12, 2002 priority date due to a lack of written description and enablement in the parent applications. Specifically, Petitioner argued that no parent application before February 7, 2011, provided written description for the generic "metal oxide" limitation, and no parent application enabled the full scope of claim 6’s "less than 10 Ω-µm²" resistivity limitation. With an effective priority date of 2011 or later, Grupp, which issued in 2007 and shares a common ancestor with the ’395 patent, qualifies as prior art under §102.
  • Prior Art Mapping: Petitioner asserted that Grupp anticipates every limitation of the challenged claims. For independent claim 1, Grupp allegedly discloses an electrical junction with an interface layer between a metal contact and a semiconductor substrate. Petitioner argued that Grupp’s disclosure of an interface layer containing a passivating material (a semiconductor oxide) and a separation layer (titanium dioxide, a metal oxide) meets the key claim limitation of an interface layer "comprising a metal oxide and a semiconductor oxide." For claim 6, Petitioner asserted that Grupp discloses achieving specific contact resistances of "less than or equal to approximately 10 Ω-µm²," thus teaching a point within the claimed range and anticipating the claim.

4. Key Claim Construction Positions

• Petitioner argued that the term "specific contact resistivity" in claim 6 should be construed to mean "specific contact resistance."
• This construction was asserted to be consistent with the interchangeable use of the terms by a person of ordinary skill in the art (POSITA) and is supported by the ’395 patent’s specification, which uses "specific contact resistance" but not "specific contact resistivity" when discussing the invention. This interpretation is central to mapping the disclosures of Grupp, which discusses "specific contact resistance," to the limitation in claim 6.

5. Key Technical Contentions (Beyond Claim Construction)

• Lack of Written Description for Generic "Metal Oxide": Petitioner’s primary technical contention was that the ’395 patent’s parent applications fail to provide adequate written description to support the generic claim term "metal oxide" and are therefore not entitled to a priority date earlier than February 7, 2011. The parent applications allegedly only disclose a single species, titanium dioxide (TiO2), as a potential interface layer metal oxide. Petitioner argued this single example is insufficient to support the entire genus because the operability of other metal oxides was unpredictable and some, like hafnium oxide, have vastly different barrier properties, meaning a POSITA could not visualize or recognize the full scope of the genus from the limited disclosure.
• Lack of Enablement for Claim 6’s Resistivity Range: Petitioner contended that claim 6 is not entitled to any priority date before the ’395 patent’s filing date (January 23, 2018) because its parent applications fail to enable the full, open-ended scope of the limitation "specific contact resistivity... of less than 10 Ω-µm²." Petitioner argued this language covers a range down to and including zero resistivity. However, the patent’s own disclosure (Fig. 8) shows a theoretical minimum specific contact resistance, implying that values below this minimum (including zero) are unachievable. Citing Magsil, Petitioner argued that because the specification does not teach how to achieve the full scope of the claimed range, the claim is not enabled by the parent applications.

6. Arguments Regarding Discretionary Denial

• Arguments against §325(d) Denial: Petitioner argued that institution is not barred by §325(d) because the U.S. Patent and Trademark Office never previously considered the same arguments. While Grupp was cited in information disclosure statements during prosecution, no examiner ever applied it against any claims of the ’395 patent or its parents. Critically, Petitioner asserted that the Office never considered the central priority date challenge presented in the petition, which is a new argument that reframes Grupp’s status as prior art.
• Arguments against §314(a) Fintiv Denial: Petitioner argued that the factors from Apple Inc. v. Fintiv, Inc. weigh in favor of institution despite a co-pending district court litigation (Acorn Semi, LLC v. Samsung).
  • The district court has a known practice of granting stays after IPR institution, even late in a case.
  • The trial date in the litigation was not fixed and could change, reducing the likelihood of it preceding a Final Written Decision (FWD).
  • Investment in the litigation was minimal as infringement contentions covering 108 claims across six patents had only recently been served.
  • Overlap would be minimized because Petitioner would cease asserting Grupp in the litigation if the IPR is instituted, and the IPR presents a strong, previously unaddressed priority challenge that is best resolved by the Board.

7. Relief Requested

• Petitioner requested that the Board institute an inter partes review and cancel claims 1-6, 8-12, and 14-16 of the ’395 patent as unpatentable.