Patents by Inventor Tatsunori Toyota

Tatsunori Toyota 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: 20120256327
    Abstract: A semiconductor device and a manufacturing method therefor, wherein, during lift-off, no cracks due to internal stresses occur in the compound semiconductor layer. A method for manufacturing a semiconductor device having a structure in which a semiconductor layer is bonded on a supporting substrate, including: a device region formation step of forming a device region including the semiconductor layer on a growth substrate through a lift-off layer; a columnar member formation step of forming a columnar member on the growth substrate; a bonding step of bonding the tops of the semiconductor layer and the columnar member to a supporting substrate; a lift-off step of separating the bottom face of the semiconductor layer from the growth substrate by removing the lift-off layer, and not separating the columnar member from the growth substrate; and a step of separating the columnar member from the supporting substrate.
    Type: Application
    Filed: July 26, 2011
    Publication date: October 11, 2012
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yoshitaka Kadowaki, Tatsunori Toyota
  • Publication number: 20120248458
    Abstract: A method for manufacturing vertically structured Group III nitride semiconductor LED chips includes a step of forming a light emitting laminate on a growth substrate; a step of forming a plurality of separate light emitting structures by partially removing the light emitting laminate to partially expose the growth substrate; a step of forming a conductive support on the plurality of light emitting structures; a step of lifting off the growth substrate from the plurality of light emitting structures; and a step of cutting the conductive support thereby singulating a plurality of LED chips each having the light emitting structure. The step of partially removing the light emitting laminate is performed such that each of the plurality of light emitting structures has a top view shape of a circle or a 4n-gon en” is a positive integer) having rounded corners.
    Type: Application
    Filed: November 5, 2009
    Publication date: October 4, 2012
    Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., WAVESQUARE INC.
    Inventors: Meoung Whan Cho, Seog Woo Lee, Pil Guk Jang, Ryuichi Toba, Tatsunori Toyota, Yoshitaka Kadowaki
  • Publication number: 20120061683
    Abstract: An object of the present invention is to provide a Group III nitride semiconductor epitaxial substrate, a Group III nitride semiconductor element, and a Group III nitride semiconductor free-standing substrate, which have good crystallinity, with not only AlGaN, GaN, and GaInN the growth temperature of which is 1050° C. or less, but also with AlxGa1-xN having a high Al composition, the growth temperature of which is high; a Group III nitride semiconductor growth substrate used for producing these, and a method for efficiently producing those. The present invention provides a Group III nitride semiconductor growth substrate comprising a crystal growth substrate including a surface portion composed of a Group III nitride semiconductor which contains at least Al, and a scandium nitride film formed on the surface portion are provided.
    Type: Application
    Filed: March 25, 2010
    Publication date: March 15, 2012
    Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA HOLDINGS CO., LTD.
    Inventors: Ryuichi Toba, Masahito Miyashita, Tatsunori Toyota, Yoshitaka Kadowaki
  • Publication number: 20110254135
    Abstract: An object of the present invention is to address the problems described herein and to provide a III-nitride semiconductor epitaxial substrate, a III-nitride semiconductor element, and a III-nitride semiconductor freestanding substrate, which have good crystallinity, not only with AlGaN, GaN, or GaInN, the growth temperature of which is at or below 1050° C., but also with AlxGa1-xN, the growth temperature of which is high and which has a high Al composition, as well as a III-nitride semiconductor growth substrate for fabricating these and a method for efficiently fabricating these. The invention is characterized by being equipped with: a crystal growth substrate, at least the surface portion of which substrate includes a III-nitride semiconductor containing Al; and a single metallic layer formed on the surface portion, the single metallic layer being made from Zr or Hf.
    Type: Application
    Filed: December 25, 2009
    Publication date: October 20, 2011
    Applicants: DOWA HOLDINGS CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Ryuichi Toba, Masahito Miyashita, Tatsunori Toyota