Micron Technology Inc v. Flamm Daniel

1. Case Identification

• Case #: IPR2017-00406
• Patent #: 5,711,849
• Filed: December 2, 2016
• Petitioner(s): Micron Technology, Inc., Intel Corporation, and GLOBALFOUNDRIES U.S., Inc.
• Patent Owner(s): Daniel L. Flamm
• Challenged Claims: 1-29

2. Patent Overview

• Title: Process Optimization In Gas Phase Dry Etching
• Brief Description: The ’849 patent discloses methods for optimizing semiconductor fabrication processes, particularly plasma etching. The core of the invention is a method for modeling gaseous diffusion and surface chemical reactions to predict etch rate uniformity by extracting a "surface reaction rate constant" from measured, non-uniform etch profile data, thereby avoiding costly trial-and-error reactor design and process development.

3. Grounds for Unpatentability

Ground 1: Claims 1-29 are obvious over Alkire in view of Galewski under 35 U.S.C. §103.

• Prior Art Relied Upon: Alkire (a 1985 journal article on plasma etching modeling) and Galewski (a 1991 journal article on chemical vapor deposition modeling).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Alkire and Galewski collectively teach every limitation of the challenged claims. Alkire disclosed a mathematical model for diffusion-limited plasma etching in a co-axial barrel reactor, which included key concepts from the ’849 patent, such as a first-order etching reaction, a non-uniform etch profile, and the use of a theoretical "etch rate constant" (k₂) to predict uniformity. However, Alkire’s model was purely theoretical and lacked experimental validation. Galewski remedied this deficiency by teaching a similar modeling approach for the analogous process of low-pressure chemical vapor deposition (LPCVD). Crucially, Galewski taught the steps of experimentally measuring non-uniform film deposition rates using a stylus profiler, using that empirical data to derive a surface-rate constant (ks') via a best-fit analysis, and then using that constant and the validated model to design or improve a reactor for device fabrication. Petitioner contended that combining Galewski’s method of empirical data collection and constant extraction with Alkire’s plasma etching model renders the claimed invention obvious.
  • Motivation to Combine: Petitioner asserted multiple motivations for a person of ordinary skill in the art (POSITA) to combine the references. The primary motivation was to improve Alkire’s purely theoretical model with Galewski's demonstrated method of using experimental data to validate and refine the model’s predictive accuracy. A POSITA would have recognized the known similarities between the plasma etching process of Alkire and the LPCVD process of Galewski, as both involve gas-phase diffusion and surface reactions in similar co-axial reactors. Alkire itself noted that a "similar analysis can be applied to LPCVD processes." Applying Galewski's proven validation technique to Alkire's model was argued to be a straightforward application of a known technique to a known problem (improving process models) to achieve a predictable result (a more accurate and useful model for reactor design and process optimization).
  • Expectation of Success: A POSITA would have had a reasonable expectation of success in combining the references because of the well-understood analogies between plasma etching and LPCVD. Since both processes are governed by similar principles of mass transport and surface reaction kinetics, a POSITA would expect that a method for empirically validating a model for one process (Galewski) would be successfully applicable to a similar model for the other (Alkire).

4. Key Claim Construction Positions

• "surface reaction rate constant" (all claims): Petitioner argued this term is central to all claims and proposed it be construed as "a temperature-dependent reaction rate constant for the chemical reaction between a gas phase etchant and the surface of an etchable material."
  • Petitioner also proposed an alternative, slightly narrower construction: "a reaction rate constant having a temperature dependence defined by an Arrhenius relationship for the chemical reaction between a gas phase etchant and the surface of an etchable material."
  • The petition asserted that the combination of Alkire and Galewski renders all challenged claims obvious under either proposed construction, as Galewski explicitly disclosed a surface-rate constant that follows an Arrhenius relationship.

5. Key Technical Contentions (Beyond Claim Construction)

• Analogous Nature of Etching and Deposition: A central technical contention underpinning the obviousness argument was that a POSITA would have viewed the plasma etching process in Alkire and the LPCVD process in Galewski as analogous arts that could be modeled using the same fundamental principles. Petitioner argued that both are diffusion-limited, first-order surface reactions occurring in similar reactors. This analogy provided the technical basis for why a skilled artisan would look to Galewski’s teachings on model validation to improve upon Alkire’s theoretical etching model.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-29 of Patent 5,711,849 as unpatentable.