Patents by Inventor Keiichi Yabusaki

Keiichi Yabusaki 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 devices, and methods of manufacture of the same
    Patent number: 6847055
    Abstract: The semiconductor laser device has the lower clad layer, active layer, upper clad layer, contact layer, the insulating film, and the positive electrode sequentially formed on the semiconductor substrate. The upper clad layer, the contact layer and the insulating film form the ridge. The positive electrode covers the upper and side faces of the ridge. The thickness of the positive electrode on the upper and side faces of the ridge is preferably substantially the same and it is not less than 150 nm.
    Type: Grant
    Filed: October 30, 2003
    Date of Patent: January 25, 2005
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Keiichi Yabusaki, Michio Ohkubo
  • Semiconductor devices, and methods of manufacture of the same
    Publication number: 20040084685
    Abstract: The semiconductor laser device has the lower clad layer, active layer, upper clad layer, contact layer, the insulating film, and the positive electrode sequentially formed on the semiconductor substrate. The upper clad layer, the contact layer and the insulating film form the ridge. The positive electrode covers the upper and side faces of the ridge. The thickness of the positive electrode on the upper and side faces of the ridge is preferably substantially the same and it is not less than 150 nm.
    Type: Application
    Filed: October 30, 2003
    Publication date: May 6, 2004
    Applicant: The Furukawa Electric Co., Ltd.
    Inventors: 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 device and method of manufacture of the semiconductor device
    Publication number: 20020117680
    Abstract: The semiconductor laser device has a lower clad layer, an active layer, an upper clad layer, a forward mesa forming layer, a contact layer and an insulating film, sequentially formed on the semiconductor substrate. The upper clad layer, the forward mesa forming layer, the contact layer and the insulating film form a ridge. The etching speed of the forward mesa forming layer is higher than that of the upper clad layer and lower than that of the contact layer. Because of such etching speeds, the ridge having a forward mesa structure is formed.
    Type: Application
    Filed: October 23, 2001
    Publication date: August 29, 2002
    Inventors: Keiichi Yabusaki, Michio Ohkubo
  • Semiconductor devices, and methods of manufacture of the same
    Publication number: 20020096685
    Abstract: The semiconductor laser device has the lower clad layer, active layer, upper clad layer, contact layer, the insulating film, and the positive electrode sequentially formed on the semiconductor substrate. The upper clad layer, the contact layer and the insulating film form the ridge. The positive electrode covers the upper and side faces of the ridge. The thickness of the positive electrode on the upper and side faces of the ridge is preferably substantially the same and it is not less than 150 nm.
    Type: Application
    Filed: October 23, 2001
    Publication date: July 25, 2002
    Inventors: Keiichi Yabusaki, Michio Ohkubo
  • Method for fabricating a semiconductor optical device having a ridge stripe
    Patent number: 6335216
    Abstract: A method for fabricating a semiconductor laser device includes the steps of patterning a first photoresist film on a top of a ridge stripe of a laser structure by using a second photoresist film as a mask. The first photoresist film is used for selectively etching an insulator film on the ridge stripe selectively from other portion on the side surfaces of the ridge stripe. The first photoresist film is of a negative image type having a viscosity of 50 centipoises.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: January 1, 2002
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Junji Yoshida, Keiichi Yabusaki, Naoki Tsukiji
  • 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