DCT

6:22-cv-00105

Greenthread LLC v. Intel Corp

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 6:22-cv-00105, W.D. Tex., 01/23/2023
  • Venue Allegations: Venue for Dell is based on its residence and established places of business within the district. Venue for the various Sony defendants is based on allegations that they have either committed acts of infringement in the district and are not U.S. residents, or that they maintain a regular and established place of business within the district.
  • Core Dispute: Plaintiff alleges that semiconductor components (including CPUs, flash memory, and image sensors) manufactured by or for Defendants, and the end-products that contain them (such as laptops, smartphones, and gaming consoles), infringe six patents related to the use of graded dopant regions to improve semiconductor performance.
  • Technical Context: The technology concerns the fabrication of semiconductor devices, where creating a non-uniform concentration of impurities (dopants) can generate internal electric fields that enhance device speed and efficiency.
  • Key Procedural History: The complaint alleges that Defendant Sony had pre-suit knowledge of the patented technology because a Greenthread patent application was cited as prior art during the prosecution of Sony's own U.S. patents. The patents-in-suit were assigned from the inventor, Dr. G.R. Mohan Rao, to Greenthread in 2015.

Case Timeline

Date Event
2004-09-03 Priority Date for all six asserted Greenthread Patents
2013-04-16 U.S. Patent No. 8,421,195 Issues
2015-04-27 Dr. Rao assigns the then-issued patents to Greenthread
2015-11-17 U.S. Patent No. 9,190,502 Issues
2019-12-17 U.S. Patent No. 10,510,842 Issues
2020-08-04 U.S. Patent No. 10,734,481 Issues
2021-09-14 U.S. Patent No. 11,121,222 Issues
2022-04-26 U.S. Patent No. 11,316,014 Issues
2023-01-23 Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,421,195 - “Semiconductor Devices with Graded Dopant Regions”

  • Issued: April 16, 2013. (Compl. ¶45).

The Invention Explained

  • Problem Addressed: The patent describes performance limitations in conventional semiconductor devices that use uniformly doped regions. In MOS devices, such as those used in DRAMs or image sensors, unwanted "spurious minority carriers" can be generated during operation, degrading performance by, for example, reducing memory refresh times or diminishing image quality. (’195 Patent, col. 2:58-col. 3:1).
  • The Patented Solution: The invention proposes creating a "graded dopant concentration" within the semiconductor substrate. This non-uniform doping creates a "drift field" designed to sweep the unwanted minority carriers away from the sensitive, active circuitry on the device surface and deep into the substrate, where they can be harmlessly recombined. (’195 Patent, Abstract; col. 4:29-34). Figure 5B of the patent illustrates this concept, showing a "Graded dopant region to pull minority carriers from surface." (’195 Patent, Fig. 5B).
  • Technical Importance: This approach provided a method to enhance the performance and reliability of high-density integrated circuits by managing unwanted electrical noise at a fundamental level of the device physics. (Compl. ¶1; ’195 Patent, Abstract).

Key Claims at a Glance

  • The complaint asserts infringement of one or more unspecified claims of the ’195 Patent. (Compl. ¶110). Independent claim 1 is representative of the core technology.
  • Essential elements of independent claim 1 include:
    • a surface layer;
    • a substrate;
    • an active region including a source and a drain;
    • a single drift layer between the surface layer and substrate, having a "graded concentration of dopants" that creates a "first static unidirectional electric drift field" to aid the movement of minority carriers from the surface layer to the substrate; and
    • at least one well region within the drift layer, also having a graded concentration of dopants creating a "second static unidirectional electric drift field."
  • The complaint reserves the right to assert other claims, including dependent claims. (Compl. ¶106).

U.S. Patent No. 9,190,502 - “Semiconductor Devices with Graded Dopant Regions”

  • Issued: November 17, 2015. (Compl. ¶46).

The Invention Explained

  • Problem Addressed: The patent addresses the same technical challenges as the parent ’195 patent, namely the performance degradation in various semiconductor devices caused by unwanted minority charge carriers and the operational speed limits imposed by uniform doping profiles. (’502 Patent, col. 2:62-col. 3:5).
  • The Patented Solution: The solution is also the use of intentionally non-uniform, or "graded," dopant concentrations to establish built-in electric fields. These fields are engineered to control the flow of charge carriers, either to accelerate desired carriers or to sweep away unwanted ones, thereby improving device metrics like operating frequency, refresh time in memory, or sensitivity in image sensors. (’502 Patent, Abstract; col. 4:1-17).
  • Technical Importance: This patent family applies a fundamental semiconductor physics principle to a wide array of commercially significant devices, including processors, memory, and sensors, aiming for broad performance improvements. (Compl. ¶¶1-2).

Key Claims at a Glance

  • The complaint asserts infringement of one or more unspecified claims of the ’502 Patent. (Compl. ¶117). Independent claim 7 is a representative device claim.
  • Essential elements of independent claim 7 include:
    • a surface layer;
    • a substrate;
    • an active region including a source and a drain;
    • a single drift layer between the surface layer and substrate, with a "graded concentration of dopants" creating a "first static unidirectional electric drift field" to move minority carriers from the surface layer to the substrate; and
    • at least one well region in the drift layer, with a graded concentration of dopants creating a "second static unidirectional electric drift field" to move minority carriers from the surface layer to the substrate.
  • The complaint reserves the right to assert other claims. (Compl. ¶113).

Multi-Patent Capsule: U.S. Patent No. 10,510,842

  • Patent Identification: U.S. Patent No. 10,510,842, “Semiconductor Devices with Graded Dopant Regions,” issued December 17, 2019. (Compl. ¶47).
  • Technology Synopsis: This patent continues to claim semiconductor devices with graded dopant concentrations. The technology aims to improve device performance across applications like logic, memory, and image sensors by creating internal electric fields to control charge carrier movement. (’842 Patent, Abstract).
  • Asserted Claims: At least one unspecified claim. (Compl. ¶122).
  • Accused Features: The complaint accuses Intel CPUs and flash memory, Sony transistors and image sensors, and Dell products incorporating these components. (Compl. ¶¶123-126).

Multi-Patent Capsule: U.S. Patent No. 10,734,481

  • Patent Identification: U.S. Patent No. 10,734,481, “Semiconductor Devices with Graded Dopant Regions,” issued August 4, 2020. (Compl. ¶48).
  • Technology Synopsis: As a continuation in the same family, this patent covers semiconductor structures employing graded dopant regions. The stated purpose is to enhance performance metrics such as operating frequency, memory refresh time, and image quality by managing charge carriers with engineered drift fields. (’481 Patent, Abstract).
  • Asserted Claims: At least one unspecified claim. (Compl. ¶131).
  • Accused Features: The accused features include Intel CPUs and flash memory, Sony transistors and image sensors, and the Dell and Sony end-products containing them. (Compl. ¶¶132-135).

Multi-Patent Capsule: U.S. Patent No. 11,121,222

  • Patent Identification: U.S. Patent No. 11,121,222, “Semiconductor Devices with Graded Dopant Regions,” issued September 14, 2021. (Compl. ¶49).
  • Technology Synopsis: This patent further covers semiconductor devices fabricated with graded dopant concentrations. The invention described is the creation of internal electric fields to improve device performance metrics across a range of applications, including digital logic, DRAM, and imaging ICs. (’222 Patent, Abstract).
  • Asserted Claims: At least one unspecified claim. (Compl. ¶140).
  • Accused Features: The complaint targets Intel CPUs and flash memory, Sony transistors and image sensors, and the downstream Dell and Sony products that incorporate them. (Compl. ¶¶141-144).

Multi-Patent Capsule: U.S. Patent No. 11,316,014

  • Patent Identification: U.S. Patent No. 11,316,014, “Semiconductor Devices with Graded Dopant Regions,” issued April 26, 2022. (Compl. ¶50).
  • Technology Synopsis: The most recent patent in the asserted family, it likewise claims semiconductor devices with graded dopant regions. The core technology involves engineering dopant profiles to create electric fields that improve the speed, efficiency, and quality of semiconductor components. (’014 Patent, Abstract).
  • Asserted Claims: At least one unspecified claim. (Compl. ¶149).
  • Accused Features: The infringement allegations cover Intel CPUs and flash memory, Sony transistors and image sensors, and the Dell and Sony products containing these components. (Compl. ¶¶150-153).

III. The Accused Instrumentality

Product Identification

  • The complaint targets a wide range of semiconductor components and the electronic devices that incorporate them. The accused instrumentalities are broadly defined as "Accused Products" and fall into several categories:
    • Intel Accused Products: CPUs (including 10th, 11th, and 12th generation families) and flash memory products (including SSDs, microSD/SD cards). (Compl. ¶¶65, 69).
    • Sony Accused Products: Transistors and image sensors, which are incorporated into end-products like televisions, smartphones, hearing aids, and gaming systems. (Compl. ¶¶76, 83).
    • Dell Accused Products: Downstream products that incorporate accused components from Intel, Sony, Micron, and Western Digital, such as Dell Alienware, Inspiron, and XPS laptops, and Dell UltraSharp webcams containing Sony image sensors. (Compl. ¶¶28, 87, 89, 95, 102).

Functionality and Market Context

  • The complaint alleges that the accused components are fabricated using processes that create the patented "regions with graded dopant concentrations." (Compl. ¶¶67, 73, 79). The complaint provides visual evidence from Dell's website identifying its "UltraSharp 4K Webcam" as containing "a large 4K Sony STARVIS™ CMOS sensor," directly linking a Dell product to an accused Sony component. (Compl. p. 25). The complaint also includes an optical photograph of a Micron flash memory die that it alleges was manufactured by Intel and bears Intel markings, linking Intel to accused flash memory products. (Compl. p. 15, Figure 1.1.2). These components are alleged to be fundamental to the operation of a vast array of modern electronics sold by the Defendants. (Compl. ¶1, ¶83).

IV. Analysis of Infringement Allegations

The complaint repeatedly references an "Exhibit 8" that purportedly contains detailed claim charts and analysis demonstrating how exemplary accused products meet the limitations of the patents-in-suit. (Compl. ¶¶30, 66, 70, 77). As this exhibit was not provided with the complaint, the infringement allegations are summarized below in prose based on the complaint's narrative.

The core of Greenthread's infringement theory is that the accused semiconductor components—such as Intel CPUs, Sony image sensors, and various flash memory chips—are manufactured with the specific "graded dopant" structures claimed in the patents. The complaint alleges, "on information and belief," that the accused products are fabricated using "substantially similar process steps, including process steps for creating regions with graded dopant concentrations." (Compl. ¶67, ¶79). It further alleges that these graded regions function as claimed to improve device performance. The complaint asserts that specific exemplary products, such as the Intel Core i7 11800H CPU and a Micron 16nm NAND flash memory chip, have been analyzed and found to "meet each and every element of at least one claim of the Greenthread Patents." (Compl. ¶66, ¶70). The infringement allegations against the broader product families rest on the assertion that they are "in relevant part substantially similar" to these analyzed exemplars. (Compl. ¶67). The complaint supports its allegations by presenting evidence of Dell marketing products, like the Precision and Alienware lines, as containing accused Micron SSDs. (Compl. p. 23).

  • Identified Points of Contention:
    • Evidentiary Questions: The complaint's infringement theory relies heavily on analysis within the unattached Exhibit 8 and on "information and belief" allegations. A central issue for the court will be whether discovery and reverse engineering of the accused products substantiate the claim that they actually contain the specific graded dopant structures, or if any observed variations in doping are incidental to the manufacturing process rather than the functional, engineered gradients described in the patents.
    • Functional Questions: Beyond proving the physical structure, the claims require that the graded dopant concentration creates a "static unidirectional electric drift field" that "aid[s] carrier movement." A key technical question will be whether the accused structures, if found to exist, actually perform this specific function for the purposes described in the patents.

V. Key Claim Terms for Construction

  • Term: "graded dopant concentration"
    • Context and Importance: This term is the central inventive concept of all asserted patents. Its construction will likely be dispositive, as it defines the boundary between a standard, uniformly-doped semiconductor and one that practices the invention. Practitioners may focus on this term because the dispute will likely turn on whether variations in dopant levels in the accused products are merely incidental manufacturing artifacts or are the specific, functional "graded" structures claimed.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification suggests the gradient can take multiple forms, including "linear, quasi linear, exponential or complimentary error function," which may support an argument that the precise profile is not limiting. (’195 Patent, col. 3:1-3). The patent also describes the invention's applicability to a very wide range of devices, potentially supporting a broad construction covering any functionally beneficial non-uniformity. (’195 Patent, col. 1:17-30).
      • Evidence for a Narrower Interpretation: The patents consistently describe the purpose of the gradient as creating a "suitable aiding drift electric field," which could support a narrower construction requiring a deliberately engineered and functionally significant gradient. (’195 Patent, col. 3:3-5). The figures depicting the invention, such as Figure 4, show a distinct, continuous gradient, which may be argued to limit the scope to structures that mirror this embodiment. (’195 Patent, Fig. 4).
  • Term: "static unidirectional electric drift field"
    • Context and Importance: This term defines the required function of the "graded dopant concentration." The infringement analysis will depend not just on the physical structure but on proving the existence of this field.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: A party could argue that any dopant gradient will inherently produce some form of electric field, and if that field has a net directional effect on carriers, it meets the "unidirectional" limitation. The term "static" could be argued to mean simply that the field is built-in, as opposed to externally applied.
      • Evidence for a Narrower Interpretation: A party could argue "static" and "unidirectional" require a persistent, non-fluctuating field that consistently points in a single direction to "aid" carrier movement. The patent's goal of sweeping unwanted carriers "from the active circuitry at the surface into the substrate" suggests a specific and constant directionality is intended. (’195 Patent, col. 4:32-34).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that Sony induces infringement by supplying its image sensors to third parties like Apple for inclusion in products such as the iPhone. (Compl. ¶83). It also alleges inducement more broadly, claiming that Intel and Sony induce infringement by their partners (like Dell) by providing the infringing components with knowledge and intent that they will be incorporated into downstream products. (Compl. ¶¶86, 125, 134, 143, 152).
  • Willful Infringement: Willfulness is alleged against Sony. (Compl. ¶¶75, 125, 134, 143, 152). The complaint alleges pre-suit knowledge based on the USPTO's citation of a Greenthread patent application as prior art during the prosecution of Sony's own patents. (Compl. ¶82). It also alleges knowledge based on Greenthread's infringement contentions served on Dell, which allegedly put Sony on notice of its infringement. (Compl. ¶84).

VII. Analyst’s Conclusion: Key Questions for the Case

  • A central issue will be one of proof and reverse engineering: Can Greenthread produce sufficient technical evidence from the accused products themselves to demonstrate that they contain the specific "graded dopant concentration" structures as claimed, or will the allegations remain generalized and based on "information and belief"? The case may depend on what is ultimately found inside the silicon of the accused chips.
  • The case will also turn on a question of definitional scope: How will the court construe the term "graded dopant concentration"? Will it encompass any non-uniform doping profile that results in a functional benefit, or will it be limited to a more specific, intentionally engineered gradient designed to create the claimed "static unidirectional electric drift field"? The outcome of this claim construction battle will be critical for the infringement analysis.
  • Finally, for the Sony defendants, a key question will be one of scienter: Does the citation of Plaintiff's patent application during the prosecution of Sony's own patents constitute the kind of pre-suit knowledge that can support a finding of willful infringement, potentially exposing Sony to enhanced damages?