Patents by Inventor Sten Johan Heikman

Sten Johan Heikman 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).

  • GaN/AlGaN/GaN dispersion-free high electron mobility transistors
    Patent number: 7700973
    Abstract: A dispersion-free high electron mobility transistor (HEMT), comprised of a substrate; a semi-insulating buffer layer, comprised of gallium nitride (GaN) or aluminum gallium nitride (AlGaN), deposited on the substrate, an AlGaN barrier layer, with an aluminum (Al) mole fraction larger than that of the semi-insulating buffer layer, deposited on the semi-insulating buffer layer, an n-type doped graded AlGaN layer deposited on the AlGaN barrier layer, wherein an Al mole fraction is decreased from a bottom of the n-type doped graded AlGaN layer to a top of the n-type doped graded AlGaN layer, and a cap layer, comprised of GaN or AlGaN with an Al mole fraction smaller than that of the AlGaN barrier layer, deposited on the n-type doped graded AlGaN layer.
    Type: Grant
    Filed: October 12, 2004
    Date of Patent: April 20, 2010
    Assignee: The Regents of the University of California
    Inventors: Likun Shen, Sten Johan Heikman, Umesh Kumar Mishra