Patents by Inventor Katsuaki Kawara

Katsuaki Kawara 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: 11804519
    Abstract: A crystalline multilayer structure having a high-quality crystalline layer and a semiconductor device employing such a crystalline multilayer structure are provided. A crystalline multilayer structure, including a first crystalline layer having a first crystal, and a second crystalline layer stacked on the first crystalline layer and having a second crystal, wherein the first crystal includes polycrystalline ?-Ga2O3 and the second crystal is a single crystal of a crystalline oxide.
    Type: Grant
    Filed: April 26, 2021
    Date of Patent: October 31, 2023
    Assignees: FLOSFIA INC., NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Yuichi Oshima, Katsuaki Kawara
  • Patent number: 11694894
    Abstract: A high-quality crystalline film having less impurity of Si and the like and useful in semiconductor devices is provided. A crystalline film containing a crystalline metallic oxide including gallium as a main component, wherein the crystalline film includes a Si in a content of 2×1015 cm?3 or less.
    Type: Grant
    Filed: April 26, 2021
    Date of Patent: July 4, 2023
    Assignee: FLOSFIA INC.
    Inventors: Yuichi Oshima, Katsuaki Kawara
  • Publication number: 20220406943
    Abstract: Provided is a semiconductor device, including at least: a semiconductor layer; and a gate electrode that is arranged directly or via another layer on the semiconductor layer, the semiconductor device being configured in such a manner as to cause a current to flow in the semiconductor layer at least in a first direction that is along with an interface between the semiconductor layer and the gate electrode, the semiconductor layer having a corundum structure, a direction of an m-axis in the semiconductor layer being the first direction.
    Type: Application
    Filed: August 18, 2022
    Publication date: December 22, 2022
    Inventor: Katsuaki KAWARA
  • Publication number: 20220189769
    Abstract: There is provided a crystalline film including, a crystalline metal oxide as a major component; a corundum structure; a dislocation density of 1×107 cm?2 or less; and a surface area of 10 mm2 or more. There is provided a method of producing a crystalline film comprising, forming a first lateral crystal growth layer on a substrate by first lateral crystal growth; placing a mask on the first lateral crystal growth layer; and forming a second lateral crystal growth layer by second lateral crystal growth.
    Type: Application
    Filed: March 2, 2022
    Publication date: June 16, 2022
    Inventors: Katsuaki KAWARA, Yuichi OSHIMA, Mitsuru OKIGAWA
  • Publication number: 20210335995
    Abstract: A crystalline multilayer structure having a high-quality crystalline layer and a semiconductor device employing such a crystalline multilayer structure are provided. A crystalline multilayer structure, including a first crystalline layer having a first crystal, and a second crystalline layer stacked on the first crystalline layer and having a second crystal, wherein the first crystal includes polycrystalline ?-Ga2O3 and the second crystal is a single crystal of a crystalline oxide.
    Type: Application
    Filed: April 26, 2021
    Publication date: October 28, 2021
    Inventors: Yuichi OSHIMA, Katsuaki KAWARA
  • Publication number: 20210335609
    Abstract: A high-quality crystalline film having less impurity of Si and the like and useful in semiconductor devices is provided. A crystalline film containing a crystalline metallic oxide including gallium as a main component, wherein the crystalline film includes a Si in a content of 2×1015 cm?3 or less.
    Type: Application
    Filed: April 26, 2021
    Publication date: October 28, 2021
    Inventors: Yuichi OSHIMA, Katsuaki KAWARA
  • Patent number: 10460934
    Abstract: According to an aspect of a present inventive subject matter, a crystalline film includes a crystalline metal oxide as a major component, the crystalline film includes a corundum structure, a surface area that is 9 ?m2 or more, and a dislocation density that is less than 5×106 cm?2.
    Type: Grant
    Filed: August 21, 2018
    Date of Patent: October 29, 2019
    Assignees: FLOSFIA INC., NATIONAL INSTITUTE FOR MATERIALS SCIENCE, KYOTO UNIVERSITY, SAGA UNIVERSITY
    Inventors: Yuichi Oshima, Shizuo Fujita, Kentaro Kaneko, Makoto Kasu, Katsuaki Kawara, Takashi Shinohe, Tokiyoshi Matsuda, Toshimi Hitora
  • Publication number: 20190055646
    Abstract: According to an aspect of a present inventive subject matter, a method for producing a crystalline film includes gasifying a metal source to turn the metal source into a metal-containing raw-material gas; supplying the metal-containing raw-material gas and an oxygen-containing raw-material gas into a reaction chamber onto a substrate; and supplying a reactive gas into the reaction chamber onto the substrate to form a crystalline film under a gas flow of the reactive gas.
    Type: Application
    Filed: August 21, 2018
    Publication date: February 21, 2019
    Inventors: Yuichi OSHIMA, Katsuaki KAWARA, Takashi SHINOHE, Tokiyoshi MATSUDA, Toshimi HITORA
  • Publication number: 20190057865
    Abstract: According to an aspect of a present inventive subject matter, a crystalline film includes a crystalline metal oxide as a major component, the crystalline film includes a corundum structure, a surface area that is 9 ?m2 or more, and a dislocation density that is less than 5×106cm?2.
    Type: Application
    Filed: August 21, 2018
    Publication date: February 21, 2019
    Inventors: Yuichi OSHIMA, Shizuo FUJITA, Kentaro KANEKO, Makoto KASU, Katsuaki KAWARA, Takashi SHINOHE, Tokiyoshi MATSUDA, Toshimi HITORA
  • Publication number: 20190057866
    Abstract: According to an aspect of a present inventive subject matter, a crystal includes: a corundum-structured oxide semiconductor as a major component, the corundum-structured oxide semiconductor including gallium and/or indium and doped with a dopant including germanium; a principal plane; a carrier concentration that is 1×1018/cm3 or more; and an electron mobility that is 20 cm2/Vs or more.
    Type: Application
    Filed: August 21, 2018
    Publication date: February 21, 2019
    Inventors: Yuichi OSHIMA, Shizuo FUJITA, Kentaro KANEKO, Makoto KASU, Katsuaki KAWARA, Takashi SHINOHE, Tokiyoshi MATSUDA, Toshimi HITORA
  • Publication number: 20190055667
    Abstract: According to an aspect of a present inventive subject matter, a method for producing a crystalline film includes; gasifying a metal source containing a metal to turn the metal source into a metal-containing raw-material gas; supplying the metal-containing raw-material gas and an oxygen-containing raw-material gas into a reaction chamber onto a substrate including a buffer layer; and supplying a reactive gas into the reaction chamber onto the substrate to form a crystalline film on the substrate under a gas flow of the reactive gas.
    Type: Application
    Filed: August 21, 2018
    Publication date: February 21, 2019
    Inventors: Yuichi OSHIMA, Shizuo FUJITA, Kentaro KANEKO, Makoto KASU, Katsuaki KAWARA, Takashi SHINOHE, Tokiyoshi MATSUDA, Toshimi HITORA
  • Publication number: 20190043961
    Abstract: A semiconductor device is provided that is excellent in semiconductor properties and Schottky characteristics. A semiconductor device includes: a semiconductor layer containing a crystalline oxide semiconductor with a corundum structure as a major component; and a Schottky electrode on the semiconductor layer, wherein the Schottky electrode is formed by containing a metal of Groups 4-9 of the periodic table, thereby manufacturing a semiconductor device excellent in semiconductor properties and Schottky characteristics without impairing the semiconductor properties to use the semiconductor device thus obtained for a power device and the like.
    Type: Application
    Filed: October 12, 2018
    Publication date: February 7, 2019
    Applicant: FLOSFIA INC.
    Inventors: Masaya Oda, Rie Tokuda, Hitoshi Kambara, Katsuaki Kawara, Toshimi Hitora
  • Patent number: 10128349
    Abstract: A semiconductor device is provided that is excellent in semiconductor properties and Schottky characteristics. A semiconductor device includes: a semiconductor layer containing a crystalline oxide semiconductor with a corundum structure as a major component; and a Schottky electrode on the semiconductor layer, wherein the Schottky electrode is formed by containing a metal of Groups 4-9 of the periodic table, thereby manufacturing a semiconductor device excellent in semiconductor properties and Schottky characteristics without impairing the semiconductor properties to use the semiconductor device thus obtained for a power device and the like.
    Type: Grant
    Filed: December 16, 2016
    Date of Patent: November 13, 2018
    Assignee: FLOSFIA INC.
    Inventors: Masaya Oda, Rie Tokuda, Hitoshi Kambara, Katsuaki Kawara, Toshimi Hitora
  • Publication number: 20180097073
    Abstract: In a first aspect of a present inventive subject matter, a semiconductor device includes a semiconductor layer including a crystalline oxide semiconductor that comprises gallium; and a Schottky electrode that is positioned on the semiconductor layer. The semiconductor layer includes a surface area that is 3 mm2 or less.
    Type: Application
    Filed: September 27, 2017
    Publication date: April 5, 2018
    Inventors: Masaya ODA, Rie TOKUDA, Hitoshi KAMBARA, Katsuaki KAWARA, Toshimi HITORA
  • Publication number: 20170179249
    Abstract: A semiconductor device is provided that is excellent in semiconductor properties and Schottky characteristics. A semiconductor device includes: a semiconductor layer containing a crystalline oxide semiconductor with a corundum structure as a major component; and a Schottky electrode on the semiconductor layer, wherein the Schottky electrode is formed by containing a metal of Groups 4-9 of the periodic table, thereby manufacturing a semiconductor device excellent in semiconductor properties and Schottky characteristics without impairing the semiconductor properties to use the semiconductor device thus obtained for a power device and the like.
    Type: Application
    Filed: December 16, 2016
    Publication date: June 22, 2017
    Applicant: FLOSFIA INC.
    Inventors: Masaya Oda, Rie Tokuda, Hitoshi Kambara, Katsuaki Kawara, Toshimi Hitora