Samsung Electronics Co Ltd v. SiOnyx LLC

1. Case Identification

• Case #: IPR2024-00164
• Patent #: 9,064,764
• Filed: November 29, 2024
• Petitioner(s): Samsung Electronics Co., Ltd.
• Patent Owner(s): SiOnyx, LLC
• Challenged Claims: 1-25

2. Patent Overview

• Title: Light Trapping for Image Sensors
• Brief Description: The ’764 patent discloses light trapping elements for image sensor pixels intended to provide enhanced light detection. The technology involves backside and peripheral light trapping materials, which can include multi-layer structures and optional textured regions to reflect light back toward the pixel.

3. Grounds for Unpatentability

Ground 1: Anticipation/Obviousness of Claims 8-15 over Hwang

• Prior Art Relied Upon: Hwang (Patent 7,675,099).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Hwang anticipates or, at a minimum, renders obvious all limitations of claims 8-15. Hwang was described as disclosing an image sensor with multi-layered reflection structures on the base and sidewalls of pixels to improve spectral sensitivity and minimize interference. Petitioner asserted that Hwang explicitly teaches a light-sensitive pixel (a photodiode within a semiconductor pattern) with a light incident surface and an opposite backside surface. Further, Hwang’s sidewall multi-layered reflection layer was argued to be a peripheral light trapping material covering a peripheral sidewall. The core "sandwiched" structure of claim 8[d]—a high refractive index material between two lower index materials—was allegedly met by Hwang’s alternating layers of silicon (refractive index ~4) and silicon oxide (refractive index ~1.46) in both its base and sidewall reflectors.
  • Motivation to Combine (for §103 grounds): This ground was primarily presented as anticipation. In the alternative for obviousness, the motivation would be inherent in using Hwang's disclosed structures for their stated purpose.
  • Expectation of Success (for §103 grounds): A POSITA would have expected success as Hwang's teachings are directly analogous and aimed at the same goal of improving image sensor performance.

Ground 2: Obviousness of Claims 16-25 over Hwang in view of Konno

• Prior Art Relied Upon: Hwang (Patent 7,675,099) and Konno (Patent 7,709,775).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground asserted that a POSITA would have modified the image sensor of Hwang with features taught by Konno. Claim 17 requires a "sloped surface," claim 21 requires a "textured layer," and claims 16, 20, and 25 require a "metal layer" for the light trapping material. Petitioner argued Konno teaches all these features to improve image quality. Konno was shown to disclose using a second reflecting layer that can be a thin film of metal (e.g., aluminum), can have an inclined (sloped) surface to increase sensitivity, and can be formed on a textured transparent layer to scatter light and increase the photon path length.
  • Motivation to Combine: A POSITA would combine Hwang and Konno to achieve the mutually recognized goal of maximizing light absorption efficiency. A POSITA would have been motivated to incorporate Konno's sloped or textured surfaces into Hwang's device to better redirect light toward the pixel's reflective sidewalls, a principle both patents endorse. Further, using Konno’s metal reflector was presented as an obvious design choice to substitute for Hwang’s multi-layer reflector, as Konno teaches that metal layers can also reduce external noise.
  • Expectation of Success: The proposed modifications involved well-known semiconductor manufacturing techniques, such as depositing metal layers or texturing surfaces via sputtering or microlithography. A POSITA would have expected predictable results from combining these known elements.

Ground 3: Obviousness of Claims 1-5 and 7 over Hwang in view of Mori

• Prior Art Relied Upon: Hwang (Patent 7,675,099) and Mori (Japanese Application # 2011-119558).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground addressed claim 1[e], which requires that one of the low refractive index materials be "doped with a dopant to create a surface field." While Hwang provides the basic pixel and multi-layer sidewall structure (a high-index silicon layer sandwiched between low-index silicon dioxide layers), Mori was argued to provide the teaching of doping. Mori addresses the problem of dark current caused by crystal defects in image sensors. Mori's solution is to use a Si/SiO2 partition between pixels and to dope the SiO2 side film with p-type impurities (such as boron, as required by claim 3) to prevent unwanted charge flow, which Petitioner equated to creating a surface field for electrical isolation as described in the ’764 patent.
  • Motivation to Combine: A POSITA would combine these references to solve a known problem. Both Hwang and Mori use similar Si/SiO2 multi-layer structures for pixel isolation. A POSITA, recognizing the potential for dark current in Hwang's device, would have been motivated to apply Mori's specific solution—doping the silicon dioxide layers—to Hwang's analogous structure to mitigate such defects and improve electrical isolation, a benefit explicitly mentioned in the ’764 patent itself.
  • Expectation of Success: Doping is a fundamental and predictable process in semiconductor fabrication. Given the structural similarities between the sidewall partitions in Hwang and Mori, a POSITA would have reasonably expected success in implementing Mori's doping technique into Hwang's process flow.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including grounds based on Yamada (Japanese Application # 2009-188316) as a primary reference, both alone and in combination with Konno, Mori, and Schubert (a textbook on light-emitting diodes). These grounds relied on similar principles of combining known image sensor features to achieve predictable improvements.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §314(a) is inappropriate. It was asserted that no other petitions have been filed, making General Plastic factors inapplicable. Citing the Vidal memorandum, Petitioner contended that a parallel ITC proceeding should not be a basis for denial. Furthermore, the parallel district court case has been stayed, and the petition presents compelling evidence of unpatentability, arguing that Fintiv factors should not be applied to deny institution.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-25 of Patent 9,064,764 as unpatentable.