Patents by Inventor Tokutaro OKABE

Tokutaro OKABE 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).

  • Patent number: 11101404
    Abstract: A method for manufacturing a semiconductor device includes: preparing a wafer including sapphire, the wafer having an upper surface that includes a first region and a second region, the second region surrounding the first region and located at a position at least 2 ?m higher or lower than the first region; and forming a semiconductor layer at the upper surface, the semiconductor layer including at least one layer that comprises AlzGa1?zN (0.03?z?0.15).
    Type: Grant
    Filed: March 14, 2019
    Date of Patent: August 24, 2021
    Assignee: NICHIA CORPORATION
    Inventors: Yoshinori Miyamoto, Tokutaro Okabe, Yuya Kagoshima, Keisuke Higashitani, Chiaki Ozaki
  • Patent number: 10686098
    Abstract: A nitride semiconductor light emitting element includes: an n-side layer; a p-side layer; an active layer disposed between the n-side layer and the p-side layer, the active layer comprising: a well layer containing Al, Ga, and N, and a barrier layer containing Al, Ga, and N, wherein an Al content of the barrier layer is higher than an Al content of the well layer; and an electron blocking structure layer between the active layer and the p-side layer, the electron blocking structure comprising: a first electron blocking layer disposed between the p-side layer and the active layer, a second electron blocking layer disposed between the p-side layer and the first electron blocking layer, and an intermediate layer disposed between the first electron blocking layer and the second electron blocking layer.
    Type: Grant
    Filed: August 20, 2019
    Date of Patent: June 16, 2020
    Assignee: NICHIA CORPORATION
    Inventors: Koji Asada, Tokutaro Okabe
  • Patent number: 10505074
    Abstract: A nitride semiconductor light emitting element includes: an n-side layer; a p-side layer; an active layer including: a well layer containing Al, Ga, and N, and a barrier layer containing Al, Ga, and N, wherein an Al content of the barrier layer is higher than that of the well layer; and an electron blocking structure layer between the active layer and the p-side layer and including: a first electron blocking layer disposed between the p-side layer and the active layer and having a bandgap larger than that of the barrier layer, a second electron blocking layer disposed between the p-side layer and the first electron blocking layer and having a bandgap larger than that of the barrier layer, but smaller than the bandgap of the first electron blocking layer, and an intermediate layer disposed therebetween and having a bandgap smaller than that of the second electron blocking layer.
    Type: Grant
    Filed: September 21, 2016
    Date of Patent: December 10, 2019
    Assignee: NICHIA CORPORATION
    Inventors: Koji Asada, Tokutaro Okabe
  • Publication number: 20190371968
    Abstract: A nitride semiconductor light emitting element includes: an n-side layer; a p-side layer; an active layer disposed between the n-side layer and the p-side layer, the active layer comprising: a well layer containing Al, Ga, and N, and a barrier layer containing Al, Ga, and N, wherein an Al content of the barrier layer is higher than an Al content of the well layer; and an electron blocking structure layer between the active layer and the p-side layer, the electron blocking structure comprising: a first electron blocking layer disposed between the p-side layer and the active layer, a second electron blocking layer disposed between the p-side layer and the first electron blocking layer, and an intermediate layer disposed between the first electron blocking layer and the second electron blocking layer.
    Type: Application
    Filed: August 20, 2019
    Publication date: December 5, 2019
    Applicant: NICHIA CORPORATION
    Inventors: Koji ASADA, Tokutaro OKABE
  • Patent number: 10453997
    Abstract: A nitride semiconductor light emitting element includes: an n-side layer; a p-side layer; an active layer including: a well layer containing Al, Ga, and N, and a barrier layer containing Al, Ga, and N, wherein an Al content of the barrier layer is higher than that of the well layer; and an electron blocking structure layer between the active layer and the p-side layer and including: a first electron blocking layer disposed between the p-side layer and the active layer and having a bandgap larger than that of the barrier layer, a second electron blocking layer disposed between the p-side layer and the first electron blocking layer and having a bandgap larger than that of the barrier layer, but smaller than the bandgap of the first electron blocking layer, and an intermediate layer disposed therebetween and having a bandgap smaller than that of the second electron blocking layer.
    Type: Grant
    Filed: September 21, 2016
    Date of Patent: October 22, 2019
    Assignee: NICHIA CORPORATION
    Inventors: Koji Asada, Tokutaro Okabe
  • Publication number: 20190296190
    Abstract: A method for manufacturing a semiconductor device includes: preparing a wafer including sapphire, the wafer having an upper surface that includes a first region and a second region, the second region surrounding the first region and located at a position at least 2 ?m higher or lower than the first region; and forming a semiconductor layer at the upper surface, the semiconductor layer including at least one layer that comprises AlzGa1-zN (0.03?z?0.15).
    Type: Application
    Filed: March 14, 2019
    Publication date: September 26, 2019
    Applicant: NICHIA CORPORATION
    Inventors: Yoshinori MIYAMOTO, Tokutaro OKABE, Yuya KAGOSHIMA, Keisuke HIGASHITANI, Chiaki OZAKI
  • Publication number: 20180287014
    Abstract: A nitride semiconductor light emitting element includes: an n-side layer; a p-side layer; an active layer including: a well layer containing Al, Ga, and N, and a barrier layer containing Al, Ga, and N, wherein an Al content of the barrier layer is higher than that of the well layer; and an electron blocking structure layer between the active layer and the p-side layer and including: a first electron blocking layer disposed between the p-side layer and the active layer and having a bandgap larger than that of the barrier layer, a second electron blocking layer disposed between the p-side layer and the first electron blocking layer and having a bandgap larger than that of the barrier layer, but smaller than the bandgap of the first electron blocking layer, and an intermediate layer disposed therebetween and having a bandgap smaller than that of the second electron blocking layer.
    Type: Application
    Filed: September 21, 2016
    Publication date: October 4, 2018
    Applicant: NICHIA CORPORATION
    Inventors: Koji ASADA, Tokutaro OKABE