Patents by Inventor Stephen K. Lam

Stephen K. Lam has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Scalable and low-voltage electroforming-free nanoscale vanadium dioxide threshold switch devices and relaxation oscillators with current controlled negative differential resistance
    Patent number: 10600961
    Abstract: A vanadium dioxide (VO2)-based threshold switch device exhibiting current-controlled negative differential resistance (S-type NDR), an electrical oscillator circuit based on the threshold switch device, a wafer including a plurality of said devices, and a method of manufacturing said device are provided. The VO2-based threshold switch device exhibits volatile resistance switching and current-controlled negative differential resistance from the first time a sweeping voltage or voltage pulse is applied across the device without being treated with an electroforming process. Furthermore, the device exhibits substantially identical switching characteristics over at least 103 switching operations between a high resistance state (HRS) and a low resistance state (LRS), and a plurality of threshold switch devices exhibits a threshold voltage VT spreading of less than about 25%.
    Type: Grant
    Filed: June 11, 2018
    Date of Patent: March 24, 2020
    Assignee: HRL Laboratories, LLC
    Inventors: Wei Yi, Kenneth K. Tsang, Stephen K. Lam, Xiwei Bai, Jack A. Crowell, Elias A. Flores
  • SCALABLE AND LOW-VOLTAGE ELECTROFORMING-FREE NANOSCALE VANADIUM DIOXIDE THRESHOLD SWITCH DEVICES AND RELAXATION OSCILLATORS WITH CURRENT CONTROLLED NEGATIVE DIFFERENTIAL RESISTANCE
    Publication number: 20190036023
    Abstract: A vanadium dioxide (VO2)-based threshold switch device exhibiting current-controlled negative differential resistance (S-type NDR), an electrical oscillator circuit based on the threshold switch device, a wafer including a plurality of said devices, and a method of manufacturing said device are provided. The VO2-based threshold switch device exhibits volatile resistance switching and current-controlled negative differential resistance from the first time a sweeping voltage or voltage pulse is applied across the device without being treated with an electroforming process. Furthermore, the device exhibits substantially identical switching characteristics over at least 103 switching operations between a high resistance state (HRS) and a low resistance state (LRS), and a plurality of threshold switch devices exhibits a threshold voltage VT spreading of less than about 25%.
    Type: Application
    Filed: June 11, 2018
    Publication date: January 31, 2019
    Inventors: Wei Yi, Kenneth K. Tsang, Stephen K. Lam, Xiwei Bai, Jack A. Crowell, Elias A. Flores