Patents by Inventor Zenkichi Shibata

Zenkichi Shibata 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).

  • Semiconductor laser device having clad and contact layers respectively doped with Mg and method for fabricating the same
    Patent number: 6009113
    Abstract: A semiconductor laser device having high performance, low operating voltage, and long service life, and a method for fabricating the same are provided. A semiconductor multilayer film including an active layer for use of laser beam oscillation is stacked on a substrate. Then a clad layer composed of p-type AlGaAs doped with a p-type impurity Mg, and a contact layer composed of p-type GaAs doped also with Mg are grown by an LPE growth process, and further a surface layer having a high-resistance portion present in the contact layer and low in carrier concentration is removed. The active layer for use of laser beam oscillation is arranged in a substantially center of an end surface from which the laser beam is emitted.
    Type: Grant
    Filed: December 15, 1998
    Date of Patent: December 28, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Taiji Morimoto, Zenkichi Shibata, Takashi Ishizumi, Keisuke Miyazaki, Toshio Hata, Yoshinori Ohitsu
  • Semiconductor laser device having clad and contact layers respectively doped with MG and method for fabricating the same
    Patent number: 5932004
    Abstract: A semiconductor laser device having high performance, low operating voltage, and long service life, and a method for fabricating the same are provided. A semiconductor multilayer film including an active layer for use of laser beam oscillation is stacked on a substrate. Then a clad layer composed of p-type AlGaAs doped with a p-type impurity Mg, and a contact layer composed of p-type GaAs doped also with Mg are grown by an LPE growth process, and further a surface layer having a high-resistance portion present in the contact layer and low in carrier concentration is removed. The active layer for use of laser beam oscillation is arranged in a substantially center of an end surface from which the laser beam is emitted.
    Type: Grant
    Filed: May 22, 1997
    Date of Patent: August 3, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Taiji Morimoto, Zenkichi Shibata, Takashi Ishizumi, Keisuke Miyazaki, Toshio Hata, Yoshinori Ohitsu