Patents by Inventor Maki KUSHIMOTO

Maki KUSHIMOTO 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: 11909172
    Abstract: An object of the present invention is to provide a method for manufacturing an optical device having a laser diode, which method is suitable for mass production, and an optical device having a laser diode which allows accurate property evaluations thereof with small measurement errors. Specifically, the method includes: an etching process of etching a semiconductor lamination unit to form a mesa structure having a resonator end face, thereby forming a laser diode; and a reflecting layer forming process of forming a light reflecting layer such that the light reflecting layer covers entire side surfaces of the mesa structure, wherein the semiconductor lamination unit has a substate, a n-type clad layer including a nitride semiconductor layer having n-type conductivity, a light-emitting layer including at least one quantum well, and a p-type clad layer including a nitride semiconductor layer having p-type conductivity, laminated in this order.
    Type: Grant
    Filed: January 5, 2021
    Date of Patent: February 20, 2024
    Assignees: ASAHI KASEI KABUSHIKI KAISHA, National University Corporation Tokai National Higher Education and Research System
    Inventors: Ziyi Zhang, Maki Kushimoto, Hiroshi Amano
  • Publication number: 20220393073
    Abstract: A stacked body may include a support, a buffer layer, and an electrode layer, in this order, wherein the buffer layer may include one or more metals selected from the group consisting of Ga, Al, In, and Zn, and oxygen, the electrode layer comprises an oxide of magnesium and an oxide of zinc, and the electrode layer has a half width of a diffraction peak observed at 2?=34.8±0.5 deg in X-ray diffraction measurement of 0.43 deg or smaller.
    Type: Application
    Filed: November 2, 2020
    Publication date: December 8, 2022
    Applicants: IDEMITSU KOSAN CO.,LTD., NATIONAL UNIVERSITY CORPORATION TOKAI NATIONAL HIGHER EDUCATION AND RESEARCH SYSTEM, NIKKISO CO., LTD.
    Inventors: Shigekazu TOMAI, Yoshihiro UEOKA, Satoshi KATSUMATA, Maki KUSHIMOTO, Manato DEKI, Yoshio HONDA, Hiroshi AMANO
  • Publication number: 20220337035
    Abstract: A laser diode (1) includes an AlN single crystal substrate (11), an n-type cladding layer (12) formed on the substrate and including a nitride semiconductor layer having n-type conductivity, a light-emitting layer (14) formed on the n-type cladding layer and including one or more quantum wells, a p-type cladding layer (20) formed on the light-emitting layer and including a nitride semiconductor layer having p-type conductivity, and a p-type contact layer (18) formed on the p-type cladding layer and including a nitride semiconductor that includes GaN. The p-type cladding layer includes a p-type longitudinal conduction layer (16) that includes AlsGa1?sN (0.3?s?1), has a composition gradient such that the Al composition s decreases with increased distance from the substrate, and has a film thickness of less than 0.5 ?m, and a p-type transverse conduction layer (17) that includes AltGa1?tN (0<t?1).
    Type: Application
    Filed: September 25, 2020
    Publication date: October 20, 2022
    Applicants: ASAHI KASEI KABUSHIKI KAISHA, National University Corporation Tokai National Higher Education and Research System
    Inventors: Ziyi ZHANG, Maki KUSHIMOTO, Hiroshi AMANO
  • Publication number: 20220037561
    Abstract: A stacked body comprising: a semiconductor layer comprising a group III-V nitride semiconductor, and an electrode layer, wherein the electrode layer comprises magnesium oxide and zinc oxide, wherein the molar ratio of magnesium based on the sum of magnesium and zinc of the electrode layer [Mg/(Mg+Zn)] is 0.25 or more and 0.75 or less, and conductivity of the electrode layer is 1.0×10?2 S/cm or more.
    Type: Application
    Filed: September 26, 2019
    Publication date: February 3, 2022
    Applicants: IDEMITSU KOSAN CO.,LTD., NATIONAL UNIVERSITY CORPORATION TOKAI NATIONAL HIGHER EDUCATION AND RESEARCH SYSTEM, NIKKISO CO., LTD.
    Inventors: Yoshihiro UEOKA, Shigekazu TOMAI, Satoshi KATSUMATA, Maki KUSHIMOTO, Manato DEKI, Yoshio HONDA, Hiroshi AMANO
  • Publication number: 20210320477
    Abstract: A method of producing an ultraviolet laser diode with a low oscillation threshold current density includes stacking a first cladding layer, a light-emitting layer, and a second cladding layer on a substrate in this order to form a nitride semiconductor laminate (step S101), etching at least a portion of the nitride semiconductor laminate to form a mesa structure and setting the ratio between the length of the resonator end faces and the length of the side surfaces of the mesa structure in plan view between 1:5 and 1:500 (step S102), disposing first conductive material on a portion of a first area and applying heat treatment of 400° C. or higher to form a first electrode (step S103), and disposing a second conductive material in an area on the second cladding layer, at a distance of 5 um or more from the side surfaces, to form a second electrode (step S104).
    Type: Application
    Filed: April 14, 2021
    Publication date: October 14, 2021
    Applicants: ASAHI KASEI KABUSHIKI KAISHA, National University Corporation Tokai National Higher Education and Research System
    Inventors: Ziyi ZHANG, Maki KUSHIMOTO, Chiaki SASAOKA, Hiroshi AMANO
  • Publication number: 20210210924
    Abstract: An object of the present invention is to provide a method for manufacturing an optical device having a laser diode, which method is suitable for mass production, and an optical device having a laser diode which allows accurate property evaluations thereof with small measurement errors. Specifically, the method includes: an etching process of etching a semiconductor lamination unit to form a mesa structure having a resonator end face, thereby forming a laser diode; and a reflecting layer forming process of forming a light reflecting layer such that the light reflecting layer covers entire side surfaces of the mesa structure, wherein the semiconductor lamination unit has a substate, a n-type clad layer including a nitride semiconductor layer having n-type conductivity, a light-emitting layer including at least one quantum well, and a p-type clad layer including a nitride semiconductor layer having p-type conductivity, laminated in this order.
    Type: Application
    Filed: January 5, 2021
    Publication date: July 8, 2021
    Applicants: ASAHI KASEI KABUSHIKI KAISHA, National University Corporation Tokai National Higher Education and Research System
    Inventors: Ziyi ZHANG, Maki KUSHIMOTO, Hiroshi AMANO