PTAB

IPR2025-01129

GlobalFoundries Inc v. Oak IP LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Metal-Semiconductor Junctions with an Interface Layer
  • Brief Description: The ’880 patent relates to metal-semiconductor junctions that use an interface layer between a metal contact and a semiconductor. The interface layer is intended to control the junction's electrical properties, such as the Schottky barrier height, to achieve low specific contact resistivity.

3. Key Technical Contentions (Beyond Claim Construction)

  • Invalid Priority Claim for "Oxide of Titanium" Genus (Claims 1-22, 28): Petitioner argued that the challenged claims are not entitled to their asserted August 12, 2002 priority date. The parent applications allegedly fail to provide adequate written description for the broad genus of "oxide of titanium" as required by the claims. The specification discloses only a single species, titanium dioxide (TiO₂), which Petitioner contended is not representative of the entire genus. This genus, as interpreted by the Patent Owner in related litigation, includes numerous binary and ternary compounds (e.g., titanium silicon oxide, TiO, Ti₂O₃) with drastically different physical and electrical properties, ranging from insulators to conductors. Petitioner argued that disclosing a single species does not demonstrate possession of the entire, unpredictable genus. This lack of support allegedly resets the claims’ priority date to no earlier than February 19, 2016, making intervening art available.

  • Invalid Priority Claim for Contact Resistivity Ranges (Claims 26-28): Petitioner argued that the parent applications fail to enable the full scope of the claimed specific contact resistivity ranges, such as "less than 10 Ω-µm²" and "less than 1 Ω-µm²." Because these claim limitations are open-ended with no lower bound, they encompass resistivities down to approximately zero. Petitioner asserted that the patent’s own disclosure (Fig. 8) illustrates that a minimum specific contact resistance exists and that values approaching zero are unachievable. This alleged failure to enable the full claimed scope resets the priority date for these claims to the filing date of the ’880 patent itself (May 12, 2020), also making intervening art available.

4. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-22 and 26-28 over Grupp'483

  • Prior Art Relied Upon: Grupp’483 (Patent 7,176,483).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that because claims 1-22 and 26-28 are not entitled to their early priority date, Grupp’483 (issued in 2007) qualifies as prior art under 35 U.S.C. §102. Petitioner asserted that Grupp’483 discloses every limitation of the challenged claims. For independent claim 1, Grupp’483 allegedly discloses an electrical junction with an interface layer between a contact metal and a transistor's source/drain. This interface layer is described as comprising a spacer layer of titanium dioxide (TiO₂), which is an "oxide of titanium," and a semiconductor oxide passivation layer. Grupp’483 also allegedly discloses a passivation layer thickness of less than 1 nm. For claims 26-28, Petitioner contended that Grupp’483 explicitly discloses achieving specific contact resistivities of "even less than or equal to approximately 10 Ω-µm²," directly anticipating the claimed ranges.

Ground 2: Obviousness of Claims 23-25 over Jammy

  • Prior Art Relied Upon: Jammy (Patent 6,724,088), which incorporates by reference Bronner (Patent 5,792,703).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Jammy teaches incorporating a "quantum conductive barrier layer" into MOSFETs to improve device reliability and explicitly incorporates by reference transistor structures like those in Bronner. The combination of Jammy’s teachings with Bronner’s FET structure allegedly renders claim 23 obvious. Bronner discloses an FET with a metal silicide conductor and n-type silicon source/drain regions. Jammy discloses using materials like alumina or silicon oxynitride for its barrier layer, which Petitioner asserted would be understood by a person of ordinary skill in the art (POSITA) as forming a passivation layer of silicon oxide when deposited on Bronner's silicon substrate. The claimed thickness of "less than about 1 nm" was argued to be obvious due to its significant overlap with the "most preferred" range of 0.5-1.5 nm disclosed in Jammy.
    • Motivation to Combine: A POSITA would combine Jammy with Bronner because Jammy expressly suggests that its invention can be incorporated into various transistor structures, including those disclosed in Bronner, to improve device performance.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in applying Jammy's barrier layer to Bronner's conventional FET, as it involved the combination of known elements to achieve a predictable improvement in device reliability.

5. Key Claim Construction Positions

  • Petitioner referenced constructions from a Markman order in related litigation and from prior inter partes review (IPR) proceedings involving a patent from the same family.
  • "said interface layer comprising an oxide of titanium and an oxide of the semiconductor": Construed as "comprising a layer of an oxide of titanium and a distinct layer of an oxide of the semiconductor region." This construction is central to defining the claimed two-layer interface structure.
  • "passivating material": Construed as a "material capable of terminating dangling bonds at the surface of the semiconductor."
  • "specific contact resistivity": Noted as being construed by the Board in a prior IPR as interchangeable with "specific contact resistance."

6. Relief Requested

  • Petitioner requests institution of an IPR and cancellation of claims 1-28 of the ’880 patent as unpatentable.