Patents by Inventor Reiko Soejima

Reiko Soejima 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).

  • METHOD OF MANUFACTURING LIGHT EMITTING DIODE
    Publication number: 20090098676
    Abstract: A method of manufacturing a light emitting diode includes forming an active layer of a nitride semiconductor on a first conductive type of a nitride semiconductor layer, thermally treating the active layer at a first temperature, and forming a second conductive type of a nitride semiconductor layer on the active layer at a second temperature lower than the first temperature.
    Type: Application
    Filed: October 10, 2008
    Publication date: April 16, 2009
    Applicant: EUDYNA DEVICES INC.
    Inventors: Reiko SOEJIMA, Keiichi YUI, Kazuhiko HORINO
  • Optical semiconductor device having an epitaxial layer of III-V compound semiconductor material containing N as a group V element
    Patent number: 6984840
    Abstract: An optical semiconductor device includes an SiC substrate having an n-type conductivity, and an AlGaN buffer layer having an n-type conductivity formed on the SiC substrate with a composition represented as AlxGa1-xN, wherein the AlGaN buffer layer has a carrier density in the range between 3×1018–1×1020 cm?3, and the compositional parameter x is larger than 0 but smaller than 0.4 (0<x<0.4).
    Type: Grant
    Filed: May 18, 1999
    Date of Patent: January 10, 2006
    Assignee: Fujitsu Limited
    Inventors: Akito Kuramata, Shinichi Kubota, Kazuhiko Horino, Reiko Soejima
  • Semiconductor laser, semiconductor light emitting device, and methods of manufacturing the same
    Patent number: 6555403
    Abstract: There are provided a semiconductor laser, a semiconductor light emitting device, and methods of manufacturing the same wherein a threshold current density in a short wavelength semiconductor laser using a nitride compound semiconductor can be reduced. An active layer is composed of a single gain layer having a thickness of more than 3 nm, and optical guiding layers are provided between the active layer and cladding layers respectively.
    Type: Grant
    Filed: July 30, 1998
    Date of Patent: April 29, 2003
    Assignee: Fujitsu Limited
    Inventors: Kay Domen, Shinichi Kubota, Akito Kuramata, Reiko Soejima
  • OPTICAL SEMICONDUCTOR DEVICE HAVING AN EPITAXIAL LAYER OF III-V COMPOUND SEMICONDUCTOR MATERIAL CONTAINING N AS A GROUP V ELEMENT
    Publication number: 20020110945
    Abstract: An optical semiconductor device includes an SiC substrate having an n-type conductivity, and an AlGaN buffer layer having an n-type conductivity formed on the SiC substrate with a composition represented as AlxGa1−xN, wherein the AlGaN buffer layer has a carrier density in the range between 3×1018−1×1012cm−3, and the compositional parameter x is larger than 0 but smaller than 0.4 (0<x<0.4).
    Type: Application
    Filed: May 18, 1999
    Publication date: August 15, 2002
    Applicant: FUJITSU LIMITED OF KAWASAKI, JAPAN
    Inventors: AKITO KURAMATA, SHINICHI KUBOTA, KAZUHIKO HORINO, REIKO SOEJIMA