Patents by Inventor Stewart E. Hooper

Stewart E. Hooper 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).

  • MBE growth of p-type nitride semiconductor materials
    Patent number: 7648577
    Abstract: A method of growing a p-type nitride semiconductor material by molecular beam epitaxy (MBE) uses bis(cyclopentadienyl)magnesium (Cp2Mg) as the source of magnesium dopant atoms. Ammonia gas is used as the nitrogen precursor for the MBE growth process. To grow p-type GaN, for example, by the method of the invention, gallium, ammonia and Cp2Mg are supplied to an MBE growth chamber; to grow p-type AlGaN, aluminum is additionally supplied to the growth chamber. The growth process of the invention produces a p-type carrier concentration, as measured by room temperature Hall effect measurements, of up to 2 1017 cm?3, without the need for any post-growth step of activating the dopant atoms.
    Type: Grant
    Filed: November 27, 2003
    Date of Patent: January 19, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Stewart E. Hooper, Katherine L. Johnson, Valerie Bousquet, Jonathan Heffernan