Patents by Inventor Takeshi Shiojima

Takeshi Shiojima 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 element, semiconductor etchant, and method of fabricating the semiconductor laser element
    Patent number: 6853664
    Abstract: The semiconductor laser element comprises, from bottom to top, the p-AlxGa1?xAs upper clad layer, p-AlyGa1?yAs resistance control layer, and p-GaAs cap layer (where x>y>0.2). A portion of only the resistance control layer and cap layer is selectively etched. The etchant used for this etching is a mixture of organic acid and hydrogen peroxide based mixture, has such a composition such that the ratio of dissolution rate of the upper clad layer to the cap layer is between 10 and 20, and pH is between 7.4 and 7.6.
    Type: Grant
    Filed: February 25, 2003
    Date of Patent: February 8, 2005
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Takeshi Shiojima, Keiichi Yabusaki, Michio Ohkubo
  • Semiconductor laser element, semiconductor etchant, and method of fabricating the semiconductor laser element
    Publication number: 20030152123
    Abstract: The semiconductor laser element comprises, from bottom to top, the p-AlxGa1−xAs upper clad layer, p-AlyGa1−yAs resistance control layer, and p-GaAs cap layer (where x>y>0.2). A portion of only the resistance control layer and cap layer is selectively etched. The etchant used for this etching is a mixture of organic acid and hydrogen peroxide based mixture, has such a composition such that the ratio of dissolution rate of the upper clad layer to the cap layer is between 10 and 20, and pH is between 7.4 and 7.6.
    Type: Application
    Filed: February 25, 2003
    Publication date: August 14, 2003
    Applicant: THE FURUKAWA ELECTRIC CO., LTD.
    Inventors: Takeshi Shiojima, Keiichi Yabusaki, Michio Ohkubo
  • Semiconductor laser element, semiconductor etchant, and method of fabricating the semiconductor laser element
    Patent number: 6549554
    Abstract: The semiconductor laser element comprises, from bottom to top, the p-AlxGa1-xAs upper clad layer, p-AlyGa1-yAs resistance control layer, and p-GaAs cap layer (where x>y>0.2). A portion of only the resistance control layer and cap layer is selectively etched. The etchant used for this etching is a mixture of organic acid and hydrogen peroxide based mixture, has such a composition such that the ratio of dissolution rate of the upper clad layer to the cap layer is between 10 and 20, and pH is between 7.4 and 7.6.
    Type: Grant
    Filed: May 11, 2001
    Date of Patent: April 15, 2003
    Assignee: The Furukawa Electric Co., LTD
    Inventors: Takeshi Shiojima, Keiichi Yabusaki, Michio Ohkubo
  • Semiconductor laser element, semiconductor etchant, and method of fabricating the semiconductor laser element
    Publication number: 20010038654
    Abstract: The semiconductor laser element comprises, from bottom to top, the p-AlxGa1−xAs upper clad layer, p-AlyGa1−yAs resistance control layer, and p-GaAs cap layer (where x>y>0.2). A portion of only the resistance control layer and cap layer is selectively etched. The etchant used for this etching is a mixture of organic acid and hydrogen peroxide based mixture, has such a composition such that the ratio of dissolution rate of the upper clad layer to the cap layer is between 10 and 20, and pH is between 7.4 and 7.6.
    Type: Application
    Filed: May 11, 2001
    Publication date: November 8, 2001
    Applicant: THE FURUKAWA ELECTRIC CO., LTD.
    Inventors: Takeshi Shiojima, Keiichi Yabusaki, Michio Ohkubo