Patents by Inventor Yohei YUDA

Yohei YUDA 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: 11728393
    Abstract: An object is to provide a technology that can enhance electrical characteristics of a semiconductor device. A semiconductor device is a semiconductor device provided with a semiconductor element. The semiconductor device includes: an n-type single-crystal gallium oxide layer including a first main surface; an electrode disposed on the first main surface of the n-type single-crystal gallium oxide layer or above the first main surface, the electrode being an electrode of the semiconductor element; a p-type oxide semiconductor layer disposed between the n-type single-crystal gallium oxide layer and the electrode; and an amorphous gallium oxide layer disposed between the n-type single-crystal gallium oxide layer and the p-type oxide semiconductor layer.
    Type: Grant
    Filed: March 13, 2019
    Date of Patent: August 15, 2023
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yohei Yuda, Tatsuro Watahiki
  • Patent number: 11251282
    Abstract: In order to provide a power semiconductor device reducing a leakage current due to a defect layer and having a small fluctuation in a threshold voltage, included are an n-type epitaxial film layer formed on a surface of the single crystal n-type semiconductor substrate and having a concave portion and a convex portion; an insulating film formed on a first region in a top portion of the convex portion; a p-type thin film layer formed on a surface of the insulating film and a surface of the n-type epitaxial film layer to form a pn junction between the p-type thin film layer and the n-type epitaxial film layer; and an anode electrode, at least part of which is formed on a surface of the p-type thin film layer and part of which passes through the p-type thin film layer and the insulating film.
    Type: Grant
    Filed: December 18, 2018
    Date of Patent: February 15, 2022
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Tatsuro Watahiki, Yohei Yuda
  • Patent number: 11239323
    Abstract: An object is to provide a technology for enabling prevention of deterioration of characteristics of an oxide semiconductor device. The oxide semiconductor device includes an n-type gallium oxide epitaxial layer, a p-type oxide semiconductor layer, and an oxide layer. The p-type oxide semiconductor layer is disposed above the n-type gallium oxide epitaxial layer, contains an element different from gallium as a main component, and has p-type conductivity. The oxide layer is disposed between the n-type gallium oxide epitaxial layer and the p-type oxide semiconductor layer, and is made of a material different from gallium oxide and different at least partly from a material of the p-type oxide semiconductor layer.
    Type: Grant
    Filed: August 8, 2019
    Date of Patent: February 1, 2022
    Assignees: MITSUBISHI ELECTRIC CORPORATION, TOKYO INSTITUTE OF TECHNOLOGY
    Inventors: Yohei Yuda, Tatsuro Watahiki, Shinsuke Miyajima, Yuki Takiguchi
  • Patent number: 11222985
    Abstract: An n-type semiconductor layer has a single-crystal structure and is made of a wide-gap semiconducting material. A p-type semiconductor layer is provided on the n-type semiconductor layer and made of a material different from the aforementioned wide-gap semiconducting material, and has either a microcrystalline structure or an amorphous structure. An electrode is provided on at least one of the n-type semiconductor layer and the p-type semiconductor layer.
    Type: Grant
    Filed: February 14, 2017
    Date of Patent: January 11, 2022
    Assignees: Mitsubishi Electric Corporation, Tokyo Institute of Technology
    Inventors: Tatsuro Watahiki, Yohei Yuda, Akihiko Furukawa, Shinsuke Miyajima, Yuki Takiguchi
  • Publication number: 20210391428
    Abstract: An object is to provide a technology that can enhance electrical characteristics of a semiconductor device. A semiconductor device is a semiconductor device provided with a semiconductor element. The semiconductor device includes: an n-type single-crystal gallium oxide layer including a first main surface; an electrode disposed on the first main surface of the n-type single-crystal gallium oxide layer or above the first main surface, the electrode being an electrode of the semiconductor element; a p-type oxide semiconductor layer disposed between the n-type single-crystal gallium oxide layer and the electrode; and an amorphous gallium oxide layer disposed between the n-type single-crystal gallium oxide layer and the p-type oxide semiconductor layer.
    Type: Application
    Filed: March 13, 2019
    Publication date: December 16, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yohei YUDA, Tatsuro WATAHIKI
  • Publication number: 20210234009
    Abstract: An object is to provide a technology for enabling prevention of deterioration of characteristics of an oxide semiconductor device. The oxide semiconductor device includes an n-type gallium oxide epitaxial layer, a p-type oxide semiconductor layer, and an oxide layer. The p-type oxide semiconductor layer is disposed above the n-type gallium oxide epitaxial layer, contains an element different from gallium as a main component, and has p-type conductivity. The oxide layer is disposed between the n-type gallium oxide epitaxial layer and the p-type oxide semiconductor layer, and is made of a material different from gallium oxide and different at least partly from a material of the p-type oxide semiconductor layer.
    Type: Application
    Filed: August 8, 2019
    Publication date: July 29, 2021
    Applicants: Mitsubishi Electric Corporation, Tokyo Institute of Technology
    Inventors: Yohei YUDA, Tatsuro WATAHIKI, Shinsuke MIYAJIMA, Yuki TAKIGUCHI
  • Patent number: 10971634
    Abstract: An oxide semiconductor device has an improved withstand voltage when an inverse voltage is applied, while suppressing diffusion of different types of materials to a Schottky interface. The oxide semiconductor device includes an n-type gallium oxide epitaxial layer, p-type oxide semiconductor layers of an oxide that is a different material from the material for the gallium oxide epitaxial layer, a dielectric layer formed to cover at least part of a side surface of the oxide semiconductor layer, an anode electrode, and a cathode electrode. Hetero pn junctions are formed between the lower surfaces of the oxide semiconductor layers and a gallium oxide substrate or between the lower surfaces of the oxide semiconductor layers and the gallium oxide epitaxial layer.
    Type: Grant
    Filed: June 8, 2018
    Date of Patent: April 6, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yohei Yuda, Tatsuro Watahiki, Akihiko Furukawa
  • Publication number: 20210074826
    Abstract: In order to provide a power semiconductor device reducing a leakage current due to a defect layer and having a small fluctuation in a threshold voltage, included are an n-type epitaxial film layer formed on a surface of the single crystal n-type semiconductor substrate and having a concave portion and a convex portion; an insulating film formed on a first region in a top portion of the convex portion; a p-type thin film layer formed on a surface of the insulating film and a surface of the n-type epitaxial film layer to form a pn junction between the p-type thin film layer and the n-type epitaxial film layer; and an anode electrode, at least part of which is formed on a surface of the p-type thin film layer and part of which passes through the p-type thin film layer and the insulating film.
    Type: Application
    Filed: December 18, 2018
    Publication date: March 11, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuro WATAHIKI, Yohei YUDA
  • Publication number: 20200295203
    Abstract: An n-type semiconductor layer has a single-crystal structure and is made of a wide-gap semiconducting material. A p-type semiconductor layer is provided on the n-type semiconductor layer and made of a material different from the aforementioned wide-gap semiconducting material, and has either a microcrystalline structure or an amorphous structure. An electrode is provided on at least one of the n-type semiconductor layer and the p-type semiconductor layer.
    Type: Application
    Filed: February 14, 2017
    Publication date: September 17, 2020
    Applicants: Mitsubishi Electric Corporation, Tokyo Institute of Technology
    Inventors: Tatsuro WATAHIKI, Yohei YUDA, Akihiko FURUKAWA, Shinsuke MIYAJIMA, Yuki TAKIGUCHI
  • Publication number: 20200185541
    Abstract: An oxide semiconductor device has an improved withstand voltage when an inverse voltage is applied, while suppressing diffusion of different types of materials to a Schottky interface. The oxide semiconductor device includes an n-type gallium oxide epitaxial layer, p-type oxide semiconductor layers of an oxide that is a different material from the material for the gallium oxide epitaxial layer, a dielectric layer formed to cover at least part of a side surface of the oxide semiconductor layer, an anode electrode, and a cathode electrode. Hetero pn junctions are formed between the lower surfaces of the oxide semiconductor layers and a gallium oxide substrate or between the lower surfaces of the oxide semiconductor layers and the gallium oxide epitaxial layer.
    Type: Application
    Filed: June 8, 2018
    Publication date: June 11, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yohei YUDA, Tatsuro WATAHIKI, Akihiko FURUKAWA
  • Patent number: 10483110
    Abstract: A p-type oxide semiconductor is prevented from being oxidized by oxygen in an n-type oxide semiconductor even if the p-type oxide semiconductor is provided as a termination structure in the n-type oxide semiconductor. A semiconductor device includes an n-type gallium oxide substrate, an anode electrode joined to the n-type gallium oxide substrate, and a cathode electrode provided on the n-type gallium oxide substrate. Current flows between the anode electrode and the cathode electrode via the n-type gallium oxide substrate provided between the anode electrode and the cathode electrode. The semiconductor device further includes a p-type oxide semiconductor layer provided adjacent to a junction between the anode electrode and the n-type gallium oxide substrate, and a nitride layer provided between the p-type oxide semiconductor layer and the n-type gallium oxide substrate.
    Type: Grant
    Filed: June 8, 2017
    Date of Patent: November 19, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yohei Yuda, Tatsuro Watahiki
  • Publication number: 20190267237
    Abstract: A p-type oxide semiconductor is prevented from being oxidized by oxygen in an n-type oxide semiconductor even if the p-type oxide semiconductor is provided as a termination structure in the n-type oxide semiconductor. A semiconductor device includes an n-type gallium oxide substrate, an anode electrode joined to the n-type gallium oxide substrate, and a cathode electrode provided on the n-type gallium oxide substrate. Current flows between the anode electrode and the cathode electrode via the n-type gallium oxide substrate provided between the anode electrode and the cathode electrode. The semiconductor device further includes a p-type oxide semiconductor layer provided adjacent to a junction between the anode electrode and the n-type gallium oxide substrate, and a nitride layer provided between the p-type oxide semiconductor layer and the n-type gallium oxide substrate.
    Type: Application
    Filed: June 8, 2017
    Publication date: August 29, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yohei YUDA, Tatsuro WATAHIKI
  • Publication number: 20150270419
    Abstract: A photoelectric conversion element includes: a photoelectric conversion layer; and first and second electrodes formed on surfaces of the photoelectric conversion layer, wherein at least one of the first and second electrodes includes a translucent conductive base layer made of a translucent conductive material, and a translucent conductive mesh layer selectively buried in the translucent conductive base layer, having electrical resistivity lower than electrical resistivity of the translucent conductive base layer, and formed in a translucent conductive film pattern.
    Type: Application
    Filed: March 13, 2015
    Publication date: September 24, 2015
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yohei YUDA, Takayuki MORIOKA, Tsutomu MATSUURA, Tatsuro WATAHIKI