Patents by Inventor Shinichi Kohda

Shinichi Kohda 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).

  • Publication number: 20070114513
    Abstract: A back-surface-electrode type semiconductor laser of GaN-based compound has low electric resistance and high light emitting efficiency, and includes negative electrodes made of Al having a contact surface that contacts with the n-type GaN substrate. The back-surface-electrode type semiconductor laser has GaN-based compound layers laminated on an n-type GaN substrate with an area of reversal of polarity with low electric resistance and a negative electrode is disposed on the side opposite to the side of GaN-based compound layer of the GaN substrate so as to come in contact with the area of reversal of polarity.
    Type: Application
    Filed: November 17, 2006
    Publication date: May 24, 2007
    Applicant: ROHM CO., LTD.
    Inventors: Hiroaki Ohta, Shinichi Kohda
  • Publication number: 20070063215
    Abstract: Processed traces are formed on at least a part of intended cutting lines A along which a wafer (10) where a nitride semiconductor lamination portion (6) is formed on a GaN based substrate (1) is divided into chips, by irradiating with a laser beam LB having a wavelength which is longer than the band gap wavelength of the GaN based substrate 1 and an electrical field intensity which causes a multiple photons absorption, while adjusting the focal point to a constant depth d within the GaN based substrate (1) from the back surface of the wafer. After that, the wafer (10) is divided into chips along cutting starting points (12) which are formed in the vicinity of the processed traces by hitting with an impact. As a result, the wafer can be easily divided into chips, and in particular, end faces of a resonator can be formed with cleavage planes when an LD is formed.
    Type: Application
    Filed: September 15, 2006
    Publication date: March 22, 2007
    Applicant: ROHM CO., LTD.
    Inventor: Shinichi Kohda
  • Publication number: 20070026550
    Abstract: A method of manufacturing a semiconductor light emitting apparatus according to the invention includes: the mask layer forming step of forming two mask layers in descending order of etching rates from a side near a p-type semiconductor layer; the mask layer etching step; the semiconductor layer etching step; the side etching step of selectively etching a side surface of a mask layer having a high etching rate to form a groove portion in the p-type semiconductor layer; the insulating film forming step of forming an insulating film so as to cover the p-type semiconductor layer; the mask layer removing step; and the electrode layer forming step. A semiconductor light emitting apparatus according to the invention includes: a substrate; an n-type semiconductor layer; an active layer; a p-type semiconductor layer on which a mesa portion projecting above the active layer is formed; an insulating film which covers the mesa portion to expose an upper surface of the mesa portion; and an electrode layer.
    Type: Application
    Filed: July 6, 2006
    Publication date: February 1, 2007
    Inventors: Masahiro Murayama, Daisuke Nakagawa, Shinichi Kohda, Toshio Nishida
  • Publication number: 20060084245
    Abstract: A semiconductor device production method includes the steps of: forming a linear gallium nitride stripe pattern on a major surface of a substrate, the major surface of the substrate being offset from a predetermined crystal plane by offset angles of 0.1 degree to 0.5 degrees respectively defined with respect to a first crystal axis and a second crystal axis parallel to the predetermined crystal plane, the linear gallium nitride stripe pattern extending along the first crystal axis; and growing a gallium nitride compound semiconductor crystal along the predetermined crystal plane by selective lateral epitaxial growth to form a gallium nitride compound semiconductor layer on the major surface of the substrate formed with the gallium nitride stripe pattern. The first crystal axis and the second crystal axis may be perpendicular to each other. The substrate may be a sapphire substrate, a silicon carbide substrate, an aluminum nitride substrate or a gallium nitride substrate.
    Type: Application
    Filed: September 22, 2005
    Publication date: April 20, 2006
    Inventor: Shinichi Kohda
  • Publication number: 20050040407
    Abstract: Causing the growth of a GaN material with respect to a sapphire substrate using a conventional technique is inevitably followed by the occurrence of dislocations. Using a mask layer results in that the dislocations laterally flow. However, since the GaN crystal collides with a semiconductor layer that laterally grew from an adjacent region, perfect elimination of the dislocations is impossible. In view thereof, the invention is intended to provide a nitride compound-based semiconductor light emitting device which is based on using semiconductor layers that have been formed in a state of the dislocations' being less existent therein and which therefore has excellent property.
    Type: Application
    Filed: August 12, 2004
    Publication date: February 24, 2005
    Inventor: Shinichi Kohda