Patents by Inventor Lester Fuess Eastman

Lester Fuess Eastman 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).

  • Patent number: 8450774
    Abstract: In one example, we describe a new high performance AlGaN/GaN metal-insulator-semiconductor heterostructure field-effect transistor (MISHFET), which was fabricated using HfO2 as the surface passivation and gate insulator. The gate and drain leakage currents are drastically reduced to tens of nA, before breakdown. Without field plates, for 10 ?m of gate-drain spacing, the off-state breakdown voltage is 1035V with a specific on-resistance of 0.9 m?-cm2. In addition, there is no current slump observed from the pulse measurements. This is the best performance reported on GaN-based, fast power-switching devices on sapphire, up to now, which efficiently combines excellent device forward, reverse, and switching characteristics. Other variations, features, and examples are also mentioned here.
    Type: Grant
    Filed: July 12, 2010
    Date of Patent: May 28, 2013
    Assignee: Cornell University
    Inventors: Junxia Shi, Lester Fuess Eastman
  • Publication number: 20120097973
    Abstract: In one example, we describe a new high performance AlGaN/GaN metal-insulator-semiconductor heterostructure field-effect transistor (MISHFET), which was fabricated using HfO2 as the surface passivation and gate insulator. The gate and drain leakage currents are drastically reduced to tens of nA, before breakdown. Without field plates, for 10 ?m of gate-drain spacing, the off-state breakdown voltage is 1035V with a specific on-resistance of 0.9 m?-cm2. In addition, there is no current slump observed from the pulse measurements. This is the best performance reported on GaN-based, fast power-switching devices on sapphire, up to now, which efficiently combines excellent device forward, reverse, and switching characteristics. Other variations, features, and examples are also mentioned here.
    Type: Application
    Filed: July 12, 2010
    Publication date: April 26, 2012
    Inventors: Junxia Shi, Lester Fuess Eastman
  • Patent number: 6150680
    Abstract: A field effect semiconductor device including a substrate, a dipole barrier formed on the substrate, a channel layer formed on the dipole barrier, and source, gate and drain electrodes formed on the channel layer. The dipole barrier provides a potential barrier and a maximum electric field sufficient to confine electrons to the channel layer.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: November 21, 2000
    Assignee: Welch Allyn, Inc.
    Inventors: Lester Fuess Eastman, James Richard Shealy