PTAB

IPR2025-01450

SK Hynix Inc v. Advanced Memory Technologies LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Booster Circuit
  • Brief Description: The ’018 patent discloses a booster circuit, or charge pump, comprising two rows of boosting cells. The circuit uses at least one analog comparison circuit to compare potentials from the boosting cell rows and output a well bias potential to the deep N-well regions of the circuit's switching elements to improve performance.

3. Grounds for Unpatentability

Ground 1: Anticipation over Cordoba - Claims 1, 3, 4, and 7 are anticipated by Cordoba under 35 U.S.C. §102.

  • Prior Art Relied Upon: Cordoba (Patent 7,382,177).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Cordoba taught every element of the challenged claims. Cordoba’s "Vbb pump" was identified as the claimed "booster circuit," which included first and second stages corresponding to the two "boosting cell rows." Petitioner mapped Cordoba’s transistors M2, M21, M22, M4, M41, and M42 to the "analog comparison circuit" that compares input potentials (nodes N1 and N2) from each row. The comparison circuit outputs a well bias potential applied to a deep N-well ("first well region") containing a P-well ("second well region"), as claimed. For dependent claim 4, Petitioner asserted that Cordoba’s circuit was explicitly designed to output the lower ("more negative") of the two input potentials as the well bias.

Ground 2: Anticipation over Meng - Claims 1-3, 9, 10, and 12 are anticipated by Meng under 35 U.S.C. §102.

  • Prior Art Relied Upon: Meng (Patent 6,501,325).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Meng’s "cross-coupled high voltage charge pump" was a "booster circuit" with a two-row structure comprising multiple stages of boosting cells. Meng’s analog comparison circuit, comprising diode-connected transistors (208i, 210i), was shown to receive output potentials from each row and generate a well bias potential. Petitioner argued this bias potential was applied to a common deep N-well (the "first well region") shared by switching elements in both rows, meeting the limitations of claim 1. For dependent claim 3, Petitioner asserted Meng’s comparison circuit was configured to output the higher potential as the well bias. For claim 12, Petitioner pointed to Meng's disclosure of multiple boosting stages (N≥2, M≥2) and separate input potentials for each row.

Ground 3: Obviousness over Meng and Park - Claims 1-10 and 12 are obvious over Meng in view of Park.

  • Prior Art Relied Upon: Meng (Patent 6,501,325) and Park (Patent 6,914,791).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground was presented as an alternative to Ground 2. To the extent Meng was found not to explicitly teach applying the bias potential from the analog comparison circuit to the deep N-well of the switching elements themselves, Park supplied this teaching. Park disclosed a multi-stage charge pump using a triple-well structure where a well bias potential was explicitly applied to both the P-well and deep N-well of the charge transfer MOS device (switching element) to reduce the body effect.
    • Motivation to Combine: A POSITA would combine Meng with Park to realize the benefits described in both references. Meng stated that combining P-well and deep N-well biasing could reduce the body effect and minimize threshold voltage. Park provided an express solution for achieving this by teaching the application of a boosted voltage to the P-well and deep N-well of the switching device. The shared goals of improving efficiency and reducing silicon die area provided a strong motivation to integrate Park's specific biasing technique into Meng's two-row charge pump architecture.
    • Expectation of Success: Petitioner argued a POSITA would have a reasonable expectation of success because both references operated in the same technical field of charge pump design and used well-known, conventional circuit components. Integrating Park's straightforward well-biasing connection into Meng's architecture would have been a predictable modification.

4. Relief Requested

  • Petitioner requested institution of an inter partes review (IPR) and cancellation of claims 1-10 and 12 of the ’018 patent as unpatentable.