Patents Represented by Law Firm Cushman Darby & Cushman IP Group of Pillsburgy Madison & Sutro LLP
  • Light-emitting semiconductor device using group III nitrogen compound
    Patent number: 5587593
    Abstract: A light-emitting semiconductor device includes a sapphire substrate whose main surface orientation is tilted by 1 to 4 degrees from its axis "a" <1120>, and layers epitaxially formed thereon. Tilting the surface orientation of the sapphire substrate enables uniform doping of a p-type impurity into the layers epitaxially grown thereon. As a result, the luminous intensity of the light-emitting semiconductor device is improved.
    Type: Grant
    Filed: April 19, 1995
    Date of Patent: December 24, 1996
    Assignees: Toyoda Gosei Co., Ltd., Research Development Corporation of Japan
    Inventors: Norikatsu Koide, Shiro Yamazaki, Junichi Umezaki, Shinya Asami