Samsung Electronics Co Ltd v. Demaray LLC

1. Case Identification

• Case #: IPR2021-01091
• Patent #: 7,381,657
• Filed: June 11, 2021
• Petitioner(s): Samsung Electronics Co., Ltd.
• Patent Owner(s): Demaray LLC
• Challenged Claims: 1-21

2. Patent Overview

• Title: Sputtering Process Control
• Brief Description: The ’657 patent discloses a method and apparatus for depositing insulating films on a substrate within a plasma reactor. The system utilizes a pulsed-DC power supply coupled to a sputtering target via a filter and a separate RF power supply coupled to the substrate to provide bias, with the filter designed to prevent interference between the two supplies.

3. Grounds for Unpatentability

Ground 1: Obviousness over Barber and Hirose - Claims 2-4, 6, 8, 10-12, and 21 are obvious over Barber in view of Hirose.

• Prior Art Relied Upon: Barber (Patent 6,342,134) and Hirose (Patent 6,485,602).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Barber taught a reactive sputtering system for depositing insulating films (e.g., aluminum nitride) using a pulsed-DC power supply for the target and a separate RF supply to bias the substrate. Petitioner argued a person of ordinary skill in the art (POSITA) would understand that Barber’s pulsed-DC supply necessarily alternates between negative (sputtering) and positive (charge removal) voltages to deposit insulating films, thereby meeting that limitation. However, Barber did not expressly disclose the claimed “narrow band rejection filter” between the target and the DC supply. Hirose, addressing a similar plasma processing environment with two different frequency power supplies, explicitly taught using tunable band-rejection filters to isolate the supplies and prevent high-frequency current from one from damaging or interfering with the other.
  • Motivation to Combine: A POSITA implementing Barber's dual-supply system would have recognized the well-known problem of RF interference affecting the DC power supply's stability and longevity. To solve this predictable problem, a POSITA would combine Barber's system with the explicit filter solution from Hirose. This motivation was reinforced by guidance from manufacturers of commercial power supplies (like those identified in the ’657 patent), which consistently cautioned users to install an RF filter when using a DC supply in conjunction with an RF bias source.
  • Expectation of Success: The combination involved applying a known solution (Hirose's filter) to a known problem (RF interference in a dual-supply plasma system like Barber's). A POSITA would have had a high expectation of success as it involved the straightforward integration of known components according to established engineering principles to achieve a predictable result.

Ground 2: Obviousness over Barber, Hirose, and Sellers - Claim 1 is obvious over Barber, Hirose, and Sellers.

• Prior Art Relied Upon: Barber (Patent 6,342,134), Hirose (Patent 6,485,602), and Sellers (Patent 5,651,865).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground challenged independent claim 1, which added a limitation for "reconditioning the target" that includes sputtering in a metallic mode and then a poison mode. Petitioner asserted that the Barber-Hirose combination taught the base system, as described in Ground 1. Sellers was introduced to teach the reconditioning step. Sellers disclosed a target “conditioning” or "burn-in" process using pulsed DC sputtering to remove oxides and impurities from a target after its exposure to the atmosphere, a common occurrence during chamber maintenance.
  • Motivation to Combine: A POSITA would know that maintaining film quality, a key goal of Barber, required a clean target surface. After multiple deposition runs, the chamber would inevitably be vented for cleaning, exposing the target to atmospheric contaminants. To ensure subsequent depositions were not compromised, a POSITA would have been motivated to implement a standard decontamination process. Sellers provided an explicit teaching of such a "burn-in" process, making it an obvious modification to the Barber-Hirose system to ensure process repeatability and film quality.
  • Expectation of Success: Implementing a routine target cleaning procedure as taught by Sellers into the Barber-Hirose sputtering system was a standard, predictable step in semiconductor manufacturing, providing a high expectation of success.

Ground 3: Obviousness with the Addition of Belkind - Claims are obvious over prior art combinations including Belkind.

• Prior Art Relied Upon: Barber (Patent 6,342,134), Hirose (Patent 6,485,602), and Belkind (a 2000 technical article titled Pulsed-DC reactive sputtering of dielectrics).
• Core Argument for this Ground:
  • Prior Art Mapping: This line of argument (presented as Grounds 9-16) supplemented the primary combinations by adding Belkind. To the extent Barber was found not to teach a target voltage that alternates between positive and negative values, Belkind explicitly did. Belkind disclosed using pulsed-DC reactive sputtering where the voltage waveform clearly alternated between a negative "on-time" (for sputtering) and a positive "reverse time" (or "off-time").
  • Motivation to Combine: Belkind explained that this bipolar pulsing was essential to dissipate positive charge that accumulates on the insulating film being deposited on the target, thereby preventing arcing—a significant and well-known problem that degrades film quality. A POSITA seeking to optimize the Barber-Hirose system for depositing high-quality insulating films would have been motivated to incorporate Belkind's teachings to suppress arcing and improve process stability.
  • Expectation of Success: The use of bipolar pulsed-DC power supplies to mitigate arcing was a known and available technology at the time. A POSITA would have had the skill and a reasonable expectation of success in configuring the DC supply in the Barber-Hirose system to operate according to Belkind’s principles to achieve the predictable benefit of arc reduction.
• Additional Grounds: Petitioner asserted numerous additional obviousness challenges based on the Barber-Hirose and Barber-Hirose-Belkind combinations. These grounds added further references to teach specific dependent claim limitations, such as using a ceramic target (Dogheche), adjusting oxygen flow to control the refractive index (Safi), using a linear sweeping magnetron (Aokura), using an alloyed target (Segal), and setting the filter bandwidth (Sill).

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) was inappropriate. Although the Belkind reference was before the examiner in an Information Disclosure Statement, it was never substantively relied upon in a rejection or distinguished by the applicant. Petitioner contended its current presentation of Belkind, supported by expert testimony, provided a new perspective the examiner did not consider.
• Petitioner also argued against discretionary denial under Fintiv. It asserted that the co-pending district court litigation was in its infancy, with no trial date set and significant uncertainty in the schedule. Furthermore, Petitioner argued there was not a complete overlap between the invalidity grounds presented in the IPR and those likely to be litigated in district court, weighing in favor of institution.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-21 of Patent 7,381,657 as unpatentable.