PTAB

IPR2014-00523

Intel Corp v. Zond LLC

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1. Case Identification

2. Patent Overview

  • Title: Method for Generating Strongly-Ionized Plasma
  • Brief Description: The ’716 patent relates to methods for generating plasma for applications like sputtering while reducing the probability of electrical arcing. The invention discloses a two-step process: first generating a "weakly-ionized plasma," then applying an electrical pulse to transform it into a "strongly-ionized plasma."

3. Grounds for Unpatentability

Ground 1: Obviousness over Mozgrin and Kudryavtsev - Claims 22-24 are obvious over Mozgrin in view of Kudryavtsev.

  • Prior Art Relied Upon: Mozgrin (a 1995 plasma physics article) and Kudryavtsev (a 1983 technical paper on plasma ionization).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued Mozgrin taught the core two-step method of claim 14, from which claims 22-24 depend. Mozgrin’s "pre-ionization stage" (Region 1) was identified as the claimed "weakly-ionized plasma," which it teaches reduces the probability of arcing. Applying a high-voltage pulse transitions this plasma to a "high-current magnetron discharge" (Region 2), which Petitioner mapped to the claimed "strongly-ionized plasma." The specific plasma densities disclosed in Mozgrin for these regions allegedly satisfy the limitations of dependent claims 23 and 24; Mozgrin's Region 1 density (10⁹–10¹¹ cm⁻³) is less than the 10¹² cm⁻³ threshold of claim 23, and its Region 2 density (exceeding 2x10¹³ cm⁻³) is greater than the 10¹² cm⁻³ threshold of claim 24.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Kudryavtsev with Mozgrin because Mozgrin explicitly cited Kudryavtsev’s research on ionization relaxation as foundational to its own experimental design. Kudryavtsev provided the underlying physics explaining how an electrical pulse excites atoms and leads to an "explosive increase" in plasma density through stepwise ionization. This directly explains the phenomenon Mozgrin observed when transitioning its plasma from the pre-ionization stage to the high-current discharge stage.
    • Expectation of Success: A POSITA would have a high expectation of success because Mozgrin already successfully incorporated Kudryavtsev's principles. Formally combining the references would predictably explain and allow for the optimization of the plasma generation process that Mozgrin described to achieve efficient, arc-free sputtering.

Ground 2: Obviousness over Mozgrin, Kudryavtsev, and Lantsman - Claims 19 and 20 are obvious over Mozgrin in view of Kudryavtsev and Lantsman.

  • Prior Art Relied Upon: Mozgrin, Kudryavtsev, and Lantsman (Patent 6,190,512).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built on the Mozgrin/Kudryavtsev combination to address claims 19 and 20, which add limitations for "supplying feed gas to the strongly-ionized plasma to transport [it] by a rapid volume exchange." Petitioner argued Lantsman taught this element, as it discloses sputtering systems that use a continuous gas flow throughout the entire process, including the main deposition phase where the strongly-ionized plasma exists. This continuous exchange of gas is notoriously well-known for maintaining stable pressure in a sputtering chamber.
    • Motivation to Combine: A POSITA would combine Lantsman's teaching of continuous gas flow with the Mozgrin/Kudryavtsev system because both Lantsman and Mozgrin address the same technical problem: achieving stable, arc-free sputtering using a two-stage plasma process. Incorporating a continuous gas feed as taught by Lantsman would be an obvious and routine modification to improve the practical stability and operation of the experimental setup described in Mozgrin.

Ground 3: Obviousness over Wang and Kudryavtsev - Claim 21 is obvious over Wang in view of Kudryavtsev.

  • Prior Art Relied Upon: Wang (Patent 6,413,382) and Kudryavtsev.

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner presented Wang as an alternative primary reference that disclosed the core invention in a commercial context. Wang teaches a sputtering device using a low "background power" to maintain a plasma between pulses (the "weakly-ionized plasma") and applying high "peak power" pulses to create a high-density plasma for sputtering (the "strongly-ionized plasma"), explicitly for the purpose of reducing arcing. To meet claim 21's "quasi-static electric field" limitation, Petitioner argued that Wang’s specified pulse duration of at least 50 µs is substantially greater than the calculated electron collision time (approximately 0.188 µs) in its operating pressure range, thereby meeting the definition of quasi-static.
    • Motivation to Combine: A POSITA would be motivated to consider Kudryavtsev's teachings when implementing Wang's system. Wang applies sudden voltage pulses to a weakly ionized gas, which is the exact physical scenario Kudryavtsev analyzes. Kudryavtsev provides the scientific explanation—multi-step ionization via excited atoms—for the rapid increase in plasma density that Wang achieves, thereby providing a known framework to understand and optimize the performance of Wang's device.
    • Expectation of Success: The combination was argued to be predictable. Applying the known ionization principles from Kudryavtsev to Wang’s established sputtering apparatus would predictably yield an efficient, arc-free process with an enhanced sputtering rate, as each element would function as expected.

  • Additional Grounds: Petitioner asserted further obviousness challenges, including combinations adding the Mozgrin Thesis to provide more detail on Mozgrin's pulse characteristics (Ground III), adding Lantsman to the Wang-based grounds (Ground V), and adding Mozgrin's teachings on plasma densities to the Wang-based grounds (Ground VI).

4. Key Claim Construction Positions

  • Petitioner proposed that "weakly-ionized plasma" should be construed as "a lower density plasma" and "strongly-ionized plasma" as "a higher density plasma." This construction was asserted to be consistent with the patent specification and was central to the obviousness arguments. It allowed Petitioner to map the lower-density "pre-ionization" or "background" plasmas of the prior art to the "weakly-ionized" limitation, and the subsequent higher-density "sputtering" or "peak power" plasmas to the "strongly-ionized" limitation.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 19-24 of Patent 7,604,716 as unpatentable.