PTAB

IPR2025-00811

Apple Inc v. SiOnyx LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Light Trapping Device for Image Sensors
  • Brief Description: The ’764 patent discloses a light trapping device for image sensors. The technology utilizes reflective layers with differing refractive indices on the backside and periphery of a pixel to reflect incident light back towards the pixel’s photosensitive area, thereby improving light collection efficiency.

3. Grounds for Unpatentability

Ground 1: Claims 1-5 and 7 are obvious over Hwang-099, Hwang-795, and Kaes.

  • Prior Art Relied Upon: Hwang-099 (Patent 7,675,099), Hwang-795 (Korean Publication No. 2003-0001795), and Kaes (Application # 2010/0275984).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hwang-099 disclosed the core elements of the challenged claims, including a light sensitive pixel with peripheral and backside "light trapping material." This material was described as a multi-layered reflection structure, such as a "low-high-low sandwich" of silicon oxide and silicon layers, that substantially covers the pixel's peripheral sidewall and backside surface to reflect light back into the pixel.
    • Motivation to Combine (for §103 grounds): A person of ordinary skill in the art (POSITA) would combine Hwang-099 with Hwang-795 and Kaes to address known problems in image sensors. Hwang-795 was cited for its teaching of doping a low refractive index material (silicon oxide) with boron to form a borosilicate glass (BSG) in a trench. Petitioner asserted this would create a surface field to reduce electrical crosstalk between pixels. Kaes was cited for teaching the doping of a silicon dioxide layer on the backside of a substrate to create a back surface field (BSF), which reduces electron-hole recombination. A POSITA would be motivated to incorporate these known techniques into Hwang-099’s device to predictably improve its performance by increasing photosensitivity and reducing dark current.
    • Expectation of Success (for §103 grounds): A POSITA would have a reasonable expectation of success because depositing doped silicon dioxide layers and creating surface fields were well-known and common techniques for improving image sensor performance.

Ground 2: Claims 1-5 and 7 are obvious over Hong, Yamashita, Hwang-584, Kaes, and Hwang-795.

  • Prior Art Relied Upon: Hong (Application # 2007/0108476), Yamashita (Application # 2011/0019050), Hwang-584 (Korean Patent No. 10-0688584), Kaes (Application # 2010/0275984), and Hwang-795 (Korean Publication No. 2003-0001795).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner presented an alternative combination starting with Hong as the primary reference. Hong was argued to disclose a base image sensor with a light sensitive pixel, a backside light trapping material (a Distributed Bragg Reflector), and a peripheral sidewall formed by a shallow trench isolation (STI) region filled with a dielectric material.
    • Motivation to Combine (for §103 grounds): Petitioner argued a POSITA would modify Hong in a stepwise manner to enhance its functionality. First, a POSITA would combine Hong with Yamashita, which teaches forming isolation trenches in a lattice shape to completely surround each pixel, to better reduce light leakage and crosstalk than Hong's partial isolation. Next, a POSITA would replace Hong’s singular dielectric material in the STI trench with the multi-layer reflective structure from Hwang-584 to improve light trapping and reflectivity at the pixel periphery. Finally, as in Ground 1, a POSITA would incorporate the teachings of Hwang-795 and Kaes to dope the low-refractive-index layers of the peripheral and backside materials, respectively, to create surface fields that further reduce crosstalk and backside recombination.
    • Expectation of Success (for §103 grounds): The combination involved the application of known solutions (complete peripheral isolation, multi-layer reflectors, surface fields) to solve known problems (crosstalk, light loss, recombination) in a base image sensor, leading to a predictable improvement in overall device performance.

  • Additional Grounds: Petitioner asserted numerous additional obviousness challenges based on variations of the Hwang-099 and Hong combinations. These grounds incorporated references such as Konno (to teach metal reflectors), Komuro (to teach specific silicon types like polycrystalline silicon), and Mouli and/or Nozaki (to teach sloped sidewalls and backside surfaces for improved light collection).

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §314(a) or §325(d) would be inappropriate. It contended that under the General Plastic factors, it is not a proxy for an earlier petitioner (Samsung), has a strong independent interest in challenging the patent, and presents materially different grounds and arguments. Petitioner further argued that under the Fintiv factors, the parallel district court litigation is at a very early stage, with discovery having just commenced and no trial date set, weighing heavily in favor of 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.