PTAB

IPR2018-00732

Applied Materials Inc v. Cohen Uri

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Multiple Seed Layers for Metallic Interconnects
  • Brief Description: The ’445 patent describes a method for fabricating metallic interconnects on semiconductor substrates by depositing a composite seed layer structure comprising at least two distinct seed layers. The method aims to produce a continuous seed layer to facilitate void-free electrochemical filling of high-aspect-ratio openings.

3. Grounds for Unpatentability

Ground 1: Obviousness over Liu - Claims 3, 5, and 8-12 are obvious over Liu.

  • Prior Art Relied Upon: Liu (Patent 6,037,258).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Liu teaches all elements of the challenged claims. Liu describes a method for fabricating copper interconnects using a multi-step physical vapor deposition (PVD) process to deposit a first copper seed layer (5a) and a second copper seed layer (5b) within a cluster tool. Petitioner asserted that both of Liu's seed layers are inherently "continuous" as they are described as having a smooth topography and providing complete coverage, and both meet the claimed thickness requirements (e.g., >50 Å). The process in Liu, performed in situ within a cluster tool, inherently prevents exposure to air between deposition steps. Petitioner contended that using an automatic controller with recipe information to execute Liu’s multi-step PVD process would have been an obvious implementation to a person of ordinary skill in the art (POSITA) at the time. Dependent claims 3 (PVD technique), 5 (deposition order), 9 (seed layer material), 10-11 (deposition order), and 12 (barrier layer) were also argued to be fully disclosed or rendered obvious by Liu.

Ground 2: Obviousness over Liu and Gopalraja - Claims 8-12 are obvious over Liu in view of Gopalraja.

  • Prior Art Relied Upon: Liu (Patent 6,037,258) and Gopalraja (Patent 6,042,700).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground was presented to address the claim 8 limitation requiring that the second set of deposition parameters includes at least one parameter different from the first set. Petitioner argued that while Liu suggests this, Gopalraja explicitly teaches it. Gopalraja discloses a two-step sputter deposition process designed to improve layer uniformity and sidewall coverage. It achieves this by intentionally using different deposition parameters—specifically, different DC power levels applied to the sputtering target—between the first ("Center Thick Step") and second ("Edge Thick Step") deposition intervals.
    • Motivation to Combine: A POSITA would combine the teachings of Liu and Gopalraja because both references address the same field of improving PVD-deposited thin films. Liu discloses a two-step PVD seed layer process, and Gopalraja teaches a method to improve the uniformity and sidewall coverage of such PVD layers, a known problem that the ’445 patent also purports to solve. A POSITA would have been motivated to apply Gopalraja's technique of varying deposition parameters to Liu's method to improve the radial uniformity and continuity of the resulting copper seed layers.
    • Expectation of Success: The combination would predictably yield a seed layer with improved uniformity and sidewall coverage, as these were the stated benefits of Gopalraja's technique.

Ground 3: Obviousness over Liu and Nguyen - Claims 3, 5, and 8-12 are obvious over Liu in view of Nguyen.

  • Prior Art Relied Upon: Liu (Patent 6,037,258) and Nguyen (Patent 6,122,566).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground was presented to address the limitations requiring the configuration and operation of an "automatic controller" with "recipe information." While Petitioner argued Liu rendered these elements obvious, Nguyen was cited as explicitly teaching them. Nguyen describes a method and apparatus for controlling a multi-chamber semiconductor processing system (a cluster tool) using a controller that executes process recipes. The recipes in Nguyen contain detailed information including the deposition sequence, process parameters (e.g., control of valves, power supplies), and timing parameters for operating the various chambers.
    • Motivation to Combine: A POSITA would combine the references because it was well-known and standard practice to use an automatic controller, like that taught by Nguyen, to operate a multi-chamber cluster tool, like that used in Liu's process. A POSITA implementing Liu’s deposition method would have naturally and obviously used such a controller to automate the process, control deposition parameters, and ensure efficient, repeatable results.
    • Expectation of Success: Implementing Liu's process using Nguyen's controller would predictably result in the controlled and automated formation of PVD seed layers, which was the explicit purpose of controllers in this field.

4. Key Claim Construction Positions

  • "Seed Layer": Petitioner argued that should the Board require construction, the term "seed layer" should be interpreted according to its plain and ordinary meaning to a POSITA at the time of the invention. This meaning was proposed as "an electrically conductive layer that facilitates growth of a conductive material."

5. Arguments Regarding Discretionary Denial

  • Petitioner argued against discretionary denial under 35 U.S.C. §314(a) and §325(d). It asserted that the petition was not abusive under the General Plastics factors, as it was filed shortly after related IPR petitions challenging different claims of the ’445 patent. Furthermore, Petitioner contended that the grounds presented were not the same or substantially the same as those previously presented to the Board, as different claims were being challenged.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 3, 5, and 8-12 of the ’445 patent as unpatentable under 35 U.S.C. §103.