PTAB

IPR2025-00889

GlobalFoundries Inc v. Oak IP LLC

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Metal-Semiconductor Junction with Interface Layer
  • Brief Description: The ’395 patent discloses metal-semiconductor junctions that include a thin interface layer between the metal contact and the semiconductor. The interface layer is intended to modify the junction's electrical properties, such as by "depinning" the Fermi level to control the Schottky barrier height and reduce specific contact resistance.

3. Grounds for Unpatentability

Ground 1: Claims 7, 11-14, and 17-28 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 primary argument was that the challenged claims requiring an "oxide of titanium" (claims 11-14, 17-28) or a "metal oxide" (claim 7) were not entitled to their asserted 2002 priority date. Petitioner contended that the specification's disclosure of a single species, titanium dioxide (TiO₂), failed to provide adequate written description support for the broad genus of "oxide of titanium," which encompasses numerous binary and ternary compounds with widely disparate electrical, structural, and optical properties. This lack of support allegedly pushes the effective priority date for these claims past the 2007 issue date of the ’483 patent, making it qualifying prior art. Once established as prior art, Petitioner argued Grupp anticipates the claims by disclosing all required elements, including an electrical junction with a semiconductor, a metal contact, and an interface layer comprising both a semiconductor oxide (passivation layer) and an oxide of titanium (a TiO₂ separation layer).
    • Key Aspects: The viability of this ground rests on successfully challenging the priority date of the asserted claims by arguing a lack of written description support for the claimed genus.

Ground 2: Claims 29 and 30 are obvious over Jammy under 35 U.S.C. §103.

  • Prior Art Relied Upon: Jammy (Patent 6,724,088).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Jammy discloses the core structure of a MOSFET transistor comprising the elements of claim 29: a source/drain region (semiconductor), a metal electrical contact (conductive studs), and an interface layer ("quantum conductive barrier layer") disposed between them. Jammy teaches using materials like silicon oxynitride or alumina for this barrier layer, which Petitioner argued a person of ordinary skill in the art (POSITA) would recognize as an "oxide of the semiconductor." Jammy also discloses a "most preferred" thickness for this layer of 0.5-1.5 nm, which significantly overlaps with the claimed limitation of "less than 1 nm." For claim 30, which adds the limitation that the metal contact comprises titanium, Petitioner pointed to Jammy's incorporation by reference of another patent (Cote, Patent 5,216,282) that explicitly discloses using titanium for diffusion contact studs.
    • Motivation to Combine: A POSITA would be motivated to use a thickness within Jammy's "most preferred" range (0.5-1.5 nm) to achieve the disclosed electrical conductivity. The significant overlap with the claimed range of "less than 1 nm" renders the specific claimed thickness obvious. A POSITA would also be motivated to use the disclosed titanium for the metal contact as it was a known and suitable material for such structures.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because Jammy teaches using known materials within a preferred thickness range to form the claimed junction. The use of titanium as a contact metal was also conventional.

4. Key Claim Construction Positions

  • Petitioner referenced a district court’s construction for the term "said interface layer comprising an oxide of titanium and an oxide of the semiconductor" (claims 17-28).
  • The court construed this term to mean "said interface layer comprising a layer of an oxide of titanium and a distinct layer of an oxide of the semiconductor region." This construction, requiring two distinct layers, was central to Petitioner's anticipation mapping under Ground 1, where Grupp was alleged to disclose a TiO₂ separation layer and a distinct semiconductor oxide passivation layer.

5. Key Technical Contentions (Beyond Claim Construction)

  • Petitioner’s central technical contention, which underpinned multiple grounds, was that the ’395 patent’s specification failed to provide adequate written description for the genus "oxide of titanium."
  • Petitioner argued that the disclosure of a single species (TiO₂), a semi-conductive material, was not representative of the entire claimed genus. The genus, as interpreted by the Patent Owner in related litigation, includes a vast array of binary and ternary compounds (e.g., TiO, Ti₂O₃, TiSiOx) that exhibit a wide and unpredictable range of properties, from metallic conductors to insulators. Petitioner asserted that the specification failed to describe common features that would allow a POSITA to visualize or recognize the full scope of the genus, thereby invalidating the claims' entitlement to an early priority date.

6. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial would be inappropriate because the grounds raised in the petition had not been previously considered by the Patent Trial and Appeal Board.
  • Petitioner distinguished its challenges from two prior IPRs filed by a different party (Samsung). It was noted that the first prior IPR did not challenge claims 7, 13, and 17-28 on the basis of Grupp, and the second prior IPR did not challenge claims 29 and 30 at all. Therefore, Petitioner contended the Board had not previously addressed the specific anticipation and obviousness grounds asserted in this petition for the challenged claims.

7. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 7, 11-14, and 17-30 of the ’395 patent as unpatentable.