Patents by Inventor Minoru Fujita

Minoru Fujita 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: 20240313129
    Abstract: Disclosed herein is a Schottky barrier diode that includes a semiconductor substrate made of gallium oxide, a drift layer made of gallium oxide and provided on the semiconductor substrate, an anode electrode brought into Schottky contact with the drift layer, and a cathode electrode brought into ohmic contact with the semiconductor substrate. The drift layer has a center trench filled with the anode electrode. A bottom surface of the center trench is covered with an insulating film without being in contact with the anode electrode. At least a part of a side surface of the center trench is brought into Schottky contact with the anode electrode.
    Type: Application
    Filed: May 28, 2024
    Publication date: September 19, 2024
    Inventors: Jun ARIMA, Minoru FUJITA, Katsumi KAWASAKI, Jun HIRABAYASHI
  • Publication number: 20240313130
    Abstract: Disclosed herein is a junction barrier Schottky diode includes a semiconductor substrate made of gallium oxide, a drift layer made of gallium oxide and provided on the semiconductor substrate, an anode electrode brought into Schottky contact with the drift layer, and a cathode electrode brought into ohmic contact with the semiconductor substrate. The drift layer has a center trench filled with the anode electrode and a semiconductor material having a conductivity type opposite to that of the drift layer. A bottom surface of the center trench contacts the semiconductor material without being in contact with the anode electrode. At least a part of a side surface of the center trench is brought into Schottky contact with the anode electrode.
    Type: Application
    Filed: May 28, 2024
    Publication date: September 19, 2024
    Inventors: Jun ARIMA, Minoru FUJITA, Katsumi KAWASAKI, Jun HIRABAYASHI
  • Publication number: 20240243933
    Abstract: A management system that manages content data corresponding to a hash value registered in a block of a blockchain. Content data selected by a user from among pieces of content data that are management targets, is provided to a provision destination of the selected content data. Information on the provision destination of the selected content data is registered in a block of the blockchain in association with an identification number for identifying the selected content data. When the management system receives content data that is a target of authenticity determination, an identification number for identifying the content data, and user information of the content data, authenticity of the received content data is determined. In the determination of the authenticity of the received content data, the received user information is compared with the provision destination information registered in the blockchain.
    Type: Application
    Filed: January 10, 2024
    Publication date: July 18, 2024
    Inventors: ATSUSHI FUJITA, KEIICHIRO KUBO, DAIYU UENO, NAOHIKO TSUCHIDA, KEISUKE TANAKA, MINORU SAKAIDA
  • Publication number: 20240170335
    Abstract: To divide a ?-type gallium oxide substrate having a (001) plane as a main surface satisfactorily. A method of diving a gallium oxide substrate includes: a step of forming a plurality of dividing grooves along the extending direction of the (100) plane of a ?-type gallium oxide substrate having the (001) plane as the main surface; a step of processing the ?-type gallium oxide substrate into strips by cutting the substrate in a direction perpendicular to the extending direction of the dividing grooves; and a step of cleaving the strip-shaped ?-type gallium oxide substrates 10 along the dividing grooves for singulation. Since the plurality of dividing grooves are thus formed along the cleavage planes, the substrate can be divided satisfactorily without causing flaky peeling on the cleavage surfaces by cleaving the substrate along the dividing grooves.
    Type: Application
    Filed: February 24, 2022
    Publication date: May 23, 2024
    Inventors: Minoru FUJITA, Jun ARIMA, Katsumi KAWASAKI, Jun HIRABAYASHI
  • Patent number: 11946155
    Abstract: A crucible for growing a single-crystal in which a raw material melt for growing the single-crystal is solidified while being accommodated includes a side wall part configured to surround the raw material melt and a bottom part configured to support the raw material melt while being continuous with the side wall part, in which the side wall part has circumferential length redundancy inside the side wall part in a cross-sectional view. The side wall part has a portion where the circumference length is redundant inside any portion in the cross-sectional view, and when the crucible for growing a single-crystal is cooled in a cooling process after the single-crystal growth, the portion where the circumference length is redundant inside in the cross-sectional view is expanded to an outside of the crucible for growing a single-crystal.
    Type: Grant
    Filed: December 3, 2019
    Date of Patent: April 2, 2024
    Assignee: TDK CORPORATION
    Inventors: Katsumi Kawasaki, Jun Hirabayashi, Minoru Fujita, Daisuke Inokuchi, Jun Arima, Makio Kondo
  • Publication number: 20240072179
    Abstract: To prevent dielectric breakdown of a Schottky barrier diode using gallium oxide. A Schottky barrier diode has a drift layer provided on a semiconductor substrate, an anode electrode, and a cathode electrode. A width W1 of an outer peripheral trench formed in the drift layer is larger than a width W2 of a center trench. An outer peripheral wall S1 of the outer peripheral trench is curved so as to approach vertical toward the outside, while an inner peripheral wall S2 thereof is closer to vertical than the outer peripheral wall S1. This relaxes an electric field which occurs at the outer peripheral bottom portion of the outer peripheral trench upon application of a backward voltage.
    Type: Application
    Filed: January 28, 2022
    Publication date: February 29, 2024
    Inventors: Jun ARIMA, Minoru FUJITA, Katsumi KAWASAKI, Jun HIRABAYASHI
  • Patent number: 11908955
    Abstract: A Schottky barrier diode 1 includes: a semiconductor substrate made of gallium oxide; a drift layer made of gallium oxide; an anode electrode brought into Schottky contact with an upper surface of the drift layer; and a cathode electrode brought into ohmic contact with a lower surface of the semiconductor substrate. A ring-shaped outer peripheral trench is formed in the upper surface of the drift layer, and the anode electrode is partly filled in the outer peripheral trench. A ring-shaped back surface trench is formed in the lower surface of the semiconductor substrate such that the bottom thereof reaches the drift layer. This limits a current path to the area surrounded by the back surface trench, thereby mitigating electric field concentration in the vicinity of the bottom of the outer peripheral trench.
    Type: Grant
    Filed: February 4, 2021
    Date of Patent: February 20, 2024
    Assignee: TDK CORPORATION
    Inventors: Jun Arima, Minoru Fujita, Jun Hirabayashi
  • Publication number: 20240055536
    Abstract: To prevent dielectric breakdown of a Schottky barrier diode using gallium oxide. A Schottky barrier diode has a drift layer provided on a semiconductor substrate, an anode electrode, and a cathode electrode. A part of the anode electrode is embedded in an outer peripheral trench and a center trench through an insulating film. The insulating film is formed such that the thickness thereof in the depth direction of the outer peripheral trench becomes larger toward the outside, whereby an outer peripheral wall S1 of the anode electrode embedded in the outer peripheral trench is curved so as to approach vertical toward the outside. This results in relaxation of an electric field which occurs at the outer peripheral bottom portion of the outer peripheral trench upon application of a backward voltage.
    Type: Application
    Filed: January 28, 2022
    Publication date: February 15, 2024
    Inventors: Jun ARIMA, Minoru FUJITA, Katsumi KAWASAKI, Jun HIRABAYASHI
  • Patent number: 11846037
    Abstract: In a crystal manufacturing method, first, a feedstock including a tapered tip portion is disposed above a crystal growth region. Then, a side surface of the tip portion is selectively heated and melted by radiant heat traveling diagonally upward while a shape of the tip portion is maintained, and the side surface of the tip portion is physically connected to an upper surface of the crystal growth region by a material melted from the side surface. In a crystal manufacturing apparatus, the radiant heat for melting the feedstock is radiated from an electric resistance heater.
    Type: Grant
    Filed: March 23, 2022
    Date of Patent: December 19, 2023
    Assignee: TDK CORPORATION
    Inventors: Katsumi Kawasaki, Jun Arima, Minoru Fujita, Jun Hirabayashi
  • Publication number: 20230352601
    Abstract: A Schottky barrier diode includes an anode electrode which is brought into Schottky contact with a drift layer, a cathode electrode which is brought into ohmic contact with a semiconductor substrate, an insulating film covering the inner wall of a trench formed in the drift layer, a metal film covering the inner wall of the trench through the insulating film and electrically connected to the anode electrode, and a field insulating layer. The field insulating layer includes a first part positioned between an upper surface of the drift layer and the anode electrode and a second part covering the inner wall of the trench through the metal film and insulating film. With this configuration, even when misalignment occurs between the trench and the field insulating layer, dielectric breakdown can be prevented.
    Type: Application
    Filed: October 5, 2020
    Publication date: November 2, 2023
    Inventors: Minoru FUJITA, Jun ARIMA, Katsumi KAWASAKI, Jun HIRABAYASHI
  • Patent number: 11699766
    Abstract: An object of the present invention is to provide a Schottky barrier diode which is less likely to cause dielectric breakdown due to concentration of an electric field. A Schottky barrier diode includes a semiconductor substrate 20 made of gallium oxide, a drift layer 30 made of gallium oxide and provided on the semiconductor substrate 20, an anode electrode 40 brought into Schottky contact with the drift layer 30, and a cathode electrode 50 brought into ohmic contact with the semiconductor substrate 20. The drift layer 30 has an outer peripheral trench 10 formed at a position surrounding the anode electrode 40 in a plan view. An electric field is dispersed by the presence of the outer peripheral trench 10 formed in the drift layer 30. This alleviates concentration of the electric field on the corner of the anode electrode 40, making it unlikely to cause dielectric breakdown.
    Type: Grant
    Filed: August 30, 2018
    Date of Patent: July 11, 2023
    Assignee: TDK CORPORATION
    Inventors: Jun Arima, Jun Hirabayashi, Minoru Fujita, Katsumi Kawasaki, Daisuke Inokuchi
  • Publication number: 20230113129
    Abstract: A Schottky barrier diode 1 includes: a semiconductor substrate made of gallium oxide; a drift layer made of gallium oxide; an anode electrode brought into Schottky contact with an upper surface of the drift layer; and a cathode electrode brought into ohmic contact with a lower surface of the semiconductor substrate. A ring-shaped outer peripheral trench is formed in the upper surface of the drift layer, and the anode electrode is partly filled in the outer peripheral trench. A ring-shaped back surface trench is formed in the lower surface of the semiconductor substrate such that the bottom thereof reaches the drift layer. This limits a current path to the area surrounded by the back surface trench, thereby mitigating electric field concentration in the vicinity of the bottom of the outer peripheral trench.
    Type: Application
    Filed: February 4, 2021
    Publication date: April 13, 2023
    Inventors: Jun ARIMA, Minoru FUJITA, Jun HIRABAYASHI
  • Patent number: 11626522
    Abstract: A Schottky barrier diode includes a semiconductor substrate made of gallium oxide, a drift layer made of gallium oxide and provided on the semiconductor substrate, an anode electrode brought into Schottky contact with the drift layer, and a cathode electrode brought into ohmic contact with the semiconductor substrate. The drift layer has a plurality of trenches formed in a position overlapping the anode electrode in a plan view. Among the plurality of trenches, a trench positioned at the end portion has a selectively increased width. Thus, the curvature radius of the bottom portion of the trench is increased, or an edge part constituted by the bottom portion as viewed in a cross section is divided into two parts. As a result, an electric field to be applied to the bottom portion of the trench positioned at the end portion is mitigated, making dielectric breakdown less likely to occur.
    Type: Grant
    Filed: September 26, 2018
    Date of Patent: April 11, 2023
    Assignees: TDK CORPORATION, TAMURA CORPORATION, NOVEL CRYSTAL TECHNOLOGY, INC.
    Inventors: Jun Arima, Jun Hirabayashi, Minoru Fujita, Kohei Sasaki
  • Patent number: 11621357
    Abstract: An object of the present invention is to provide a Schottky barrier diode less liable to cause dielectric breakdown due to concentration of an electric field. A Schottky barrier diode according to this disclosure includes a semiconductor substrate made of gallium oxide, a drift layer made of gallium oxide and provided on the semiconductor substrate, an anode electrode 40 brought into Schottky contact with the drift layer, a cathode electrode brought into ohmic contact with the semiconductor substrate, an insulating layer provided on the drift layer so as to surround the anode electrode in a plan view, and a semiconductor layer provided on a surface of a part of the drift layer that is positioned between the anode electrode and the insulating layer and on the insulating layer. The semiconductor layer has a conductivity type opposite to that of the drift layer.
    Type: Grant
    Filed: October 9, 2019
    Date of Patent: April 4, 2023
    Assignees: TDK CORPORATION, TAMURA CORPORATION, NOVEL CRYSTAL TECHNOLOGY, INC.
    Inventors: Jun Arima, Minoru Fujita, Jun Hirabayashi, Kohei Sasaki
  • Publication number: 20230039171
    Abstract: A Schottky barrier diode includes a semiconductor substrate made of gallium oxide, a drift layer made of gallium oxide and formed on the semiconductor substrate, an anode electrode brought into Schottky contact with the drift layer, a cathode electrode brought into ohmic contact with the semiconductor substrate, an insulating film covering the inner wall of a trench formed in the drift layer, and a protective film covering the anode electrode, wherein a part of the protective film is embedded in the trench. The part of the protective film is thus embedded in the trench, so that adhesion performance between the anode electrode and protective film is enhanced. This makes it possible to prevent peeling at the boundary between the anode electrode and the protective film.
    Type: Application
    Filed: October 5, 2020
    Publication date: February 9, 2023
    Inventors: Jun ARIMA, Minoru FUJITA, Katsumi KAWASAKI, Jun HIRABAYASHI
  • Patent number: 11557681
    Abstract: An object of the present invention is to provide a Schottky barrier diode less liable to cause dielectric breakdown due to concentration of an electric field. A Schottky barrier diode according to this disclosure includes a semiconductor substrate made of gallium oxide, a drift layer made of gallium oxide and provided on the semiconductor substrate, an anode electrode brought into Schottky contact with the drift layer, and a cathode electrode brought into ohmic contact with the semiconductor substrate. The drift layer has an outer peripheral trench surrounding the anode electrode in a plan view. The surface of the drift layer positioned between the anode electrode and the outer peripheral trench is covered with a semiconductor layer having a conductivity type opposite to that of the drift layer.
    Type: Grant
    Filed: October 9, 2019
    Date of Patent: January 17, 2023
    Assignees: TDK CORPORATION, TAMURA CORPORATION, NOVEL CRYSTAL TECHNOLOGY, INC.
    Inventors: Jun Arima, Minoru Fujita, Jun Hirabayashi, Kohei Sasaki
  • Patent number: 11492724
    Abstract: A die for EFG-based single crystal growth includes a lower surface to be immersed into a raw material melt with an impurity added, a rectangular upper surface facing a seed crystal and having a long side and a short side, and a plurality of slit sections extending from the lower surface to the upper surface and causing the raw material melt to ascend from the lower surface to the upper surface. Respective longitudinal directions of openings of the plurality of slit sections on the upper surface are parallel to one another and non-parallel to the long side of the upper surface.
    Type: Grant
    Filed: January 25, 2019
    Date of Patent: November 8, 2022
    Assignee: TDK CORPORATION
    Inventors: Katsumi Kawasaki, Jun Hirabayashi, Minoru Fujita, Daisuke Inokuchi, Jun Arima, Makio Kondo
  • Patent number: 11469334
    Abstract: An object of the present invention is to provide a Schottky barrier diode less apt to cause dielectric breakdown due to concentration of an electric field. A Schottky barrier diode includes a semiconductor substrate 20 made of gallium oxide, a drift layer 30 made of gallium oxide and provided on the semiconductor substrate 20, an anode electrode 40 brought into Schottky contact with the drift layer 30, and a cathode electrode 50 brought into ohmic contact with the semiconductor substrate 20. The drift layer 30 has an outer peripheral trench 10 that surrounds the anode electrode 40 in a plan view, and the outer peripheral trench 10 is filled with a semiconductor material 11 having a conductivity type opposite to that of the drift layer 30. An electric field is dispersed by the presence of the thus configured outer peripheral trench 10. This alleviates electric field concentration on the corner of the anode electrode 40, making it less apt to cause dielectric breakdown.
    Type: Grant
    Filed: March 11, 2019
    Date of Patent: October 11, 2022
    Assignees: TDK CORPORATION, TAMURA CORPORATION, NOVEL CRYSTAL TECHNOLOGY, INC.
    Inventors: Jun Arima, Minoru Fujita, Jun Hirabayashi, Kohei Sasaki
  • Publication number: 20220307157
    Abstract: In a crystal manufacturing method, first, a feedstock including a tapered tip portion is disposed above a crystal growth region. Then, a side surface of the tip portion is selectively heated and melted by radiant heat traveling diagonally upward while a shape of the tip portion is maintained, and the side surface of the tip portion is physically connected to an upper surface of the crystal growth region by a material melted from the side surface. In a crystal manufacturing apparatus, the radiant heat for melting the feedstock is radiated from an electric resistance heater.
    Type: Application
    Filed: March 23, 2022
    Publication date: September 29, 2022
    Applicant: TDK CORPORATION
    Inventors: Katsumi KAWASAKI, Jun ARIMA, Minoru FUJITA, Jun HIRABAYASHI
  • Patent number: 11456388
    Abstract: A trench MOS Schottky diode includes a first semiconductor layer including a Ga2O3-based single crystal, a second semiconductor layer that is a layer stacked on the first semiconductor layer, includes a Ga2O3-based single crystal, and includes a trench opened on a surface thereof opposite to the first semiconductor layer, an anode electrode formed on the surface of the second semiconductor layer, a cathode electrode formed on a surface of the first semiconductor layer, an insulating film covering the inner surface of the trench of the second semiconductor layer, and a trench electrode that is buried in the trench of the second semiconductor layer so as to be covered with the insulating film and is in contact with the anode electrode. The second semiconductor layer includes an insulating dry-etching-damaged layer with a thickness of not more than 0.8 ?m in a region including the inner surface of the trench.
    Type: Grant
    Filed: February 25, 2019
    Date of Patent: September 27, 2022
    Assignees: Tamura Corporation, Novel Crystal Technology, Inc., TDK Corporation
    Inventors: Kohei Sasaki, Minoru Fujita, Jun Hirabayashi, Jun Arima