Patents by Inventor Osamu Imafuji

Osamu Imafuji 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: 20230019414
    Abstract: A crystal that is useful for semiconductor element and a semiconductor element that has enhanced electrical properties are provided. A crystal, including: a corundum structured crystalline oxide, the crystalline oxide including gallium and/or indium, and the crystalline oxide further including a metal of Group 4 of the periodic table. The crystal is used to make a semiconductor element, and the obtained semiconductor element is used to make a semiconductor device such as a power card. Also, the semiconductor element and the semiconductor device are used to make a semiconductor system.
    Type: Application
    Filed: September 23, 2022
    Publication date: January 19, 2023
    Inventors: Ryohei KANNO, Osamu IMAFUJI, Kazuyoshi NORIMATSU, Yuji KATO
  • Publication number: 20220384663
    Abstract: Provided is a semiconductor element including: a multilayer structure including: a conductive substrate; and an oxide semiconductor film arranged directly on the conductive substrate or over the conductive substrate via a different layer, the oxide semiconductor film including an oxide, as a major component, having a corundum structure, the conductive substrate having a larger area than the oxide semiconductor film.
    Type: Application
    Filed: August 5, 2022
    Publication date: December 1, 2022
    Applicant: FLOSFIA INC.
    Inventors: Yusuke MATSUBARA, Osamu IMAFUJI, Hiroyuki ANDO, Hideki TAKEHARA, Takashi SHINOHE, Mitsuru OKIGAWA
  • Publication number: 20220376056
    Abstract: Provided is a semiconductor element including: a multilayer structure including: a conductive substrate; and an oxide semiconductor film arranged directly on the conductive substrate or over the conductive substrate via a different layer, the oxide semiconductor film including an oxide, as a major component, containing gallium, the conductive substrate having a larger area than the oxide semiconductor film.
    Type: Application
    Filed: August 5, 2022
    Publication date: November 24, 2022
    Inventors: Yusuke MATSUBARA, Osamu IMAFUJI, Hiroyuki ANDO, Hideki TAKEHARA, Takashi SHINOHE, Mitsuru OKIGAWA
  • Publication number: 20220310798
    Abstract: An electrically-conductive metal oxide film that is useful for semiconductor element and a semiconductor element that has enhanced electrical properties are provided. An electrically-conductive metal oxide film comprising: a metal oxide as a major component, wherein the metal oxide includes at least a first metal selected from a metal of Group 4 of the periodic table and a second metal selected from a metal of Group 13 of the periodic table. The electrically-conductive metal oxide film is used to make a semiconductor element, and the obtained semiconductor element is used to make a semiconductor device such as a power card. Also, the semiconductor element and the semiconductor device are used to make a semiconductor system.
    Type: Application
    Filed: June 14, 2022
    Publication date: September 29, 2022
    Inventors: Ryohei KANNO, Osamu IMAFUJI, Kazuyoshi NORIMATSU, Yuji KATO
  • Publication number: 20220231174
    Abstract: Provided is a semiconductor element including at least a multilayer structure including a semiconductor layer, a first metal layer, a second metal layer and a third metal layer, the semiconductor layer including an oxide semiconductor film, the first metal layer, the second metal layer and the third metal layer being arranged on the semiconductor layer, the first metal layer, the second metal layer and the third metal layer respectively including one or two or more different metals, the first metal layer being in ohmic contact with the semiconductor layer, the second metal layer being disposed between the first metal layer and the third metal layer, and the second metal layer containing Pt or/and Pd.
    Type: Application
    Filed: April 1, 2022
    Publication date: July 21, 2022
    Inventor: Osamu IMAFUJI
  • Publication number: 20220223682
    Abstract: Provided is a semiconductor element including; a semiconductor film; and a porous layer disposed on a first surface side of the semiconductor film or a second surface side opposite from the first surface side, a porosity of the porous layer being no more than 10%.
    Type: Application
    Filed: April 1, 2022
    Publication date: July 14, 2022
    Inventors: Osamu IMAFUJI, Yusuke MATSUBARA
  • Publication number: 20220158000
    Abstract: Provided is a semiconductor device in which crystal defects due to stress concentration in a semiconductor layer caused by an insulator film are prevented, the semiconductor device that is particularly useful for power devices. A semiconductor device including at least: a semiconductor layer; a Schottky electrode; and an insulator layer provided between a part of the semiconductor layer and the Schottky electrode, wherein the semiconductor layer contains a crystalline oxide semiconductor, and wherein the insulator layer has a taper angle of 10° or less.
    Type: Application
    Filed: January 14, 2022
    Publication date: May 19, 2022
    Inventors: Mitsuru OKIGAWA, Yasushi HIGUCHI, Yusuke MATSUBARA, Osamu IMAFUJI, Takashi SHINOHE
  • Publication number: 20220140145
    Abstract: Provided are a multilayer structure in which crystal defects due to stress concentration in a semiconductor layer caused by an insulator film are prevented and a semiconductor device using the multilayer structure, the multilayer structure and the semiconductor device that are particularly useful for power devices. A multilayer structure in which an insulator film is arranged on a part of a semiconductor film, wherein the semiconductor film has a corundum structure and contains a crystalline oxide semiconductor containing one or two or more metals selected from groups 9 and 13 of the periodic table, and wherein the insulator film has a taper angle of 20° or less.
    Type: Application
    Filed: January 14, 2022
    Publication date: May 5, 2022
    Inventors: Mitsuru OKIGAWA, Yasushi HIGUCHI, Yusuke MATSUBARA, Osamu IMAFUJI, Takashi SHINOHE
  • Publication number: 20210217854
    Abstract: The semiconductor element and the semiconductor device according to the disclosure is excellent in electrical characteristics are provided. A semiconductor element, including: an electrode, and the electrode having a corundum structure. The semiconductor element is used to make a semiconductor device such as a power card. Also, the semiconductor element and the semiconductor device are used to make a semiconductor system.
    Type: Application
    Filed: January 11, 2021
    Publication date: July 15, 2021
    Inventors: Ryohei KANNO, Osamu IMAFUJI, Kazuyoshi NORIMATSU, Yuji KATO
  • Publication number: 20210217869
    Abstract: A crystal that is useful for semiconductor element and a semiconductor element that has enhanced electrical properties are provided. A crystal, including: a corundum structured crystalline oxide, the crystalline oxide including gallium and/or indium, and the crystalline oxide further including a metal of Group 4 of the periodic table. The crystal is used to make a semiconductor element, and the obtained semiconductor element is used to make a semiconductor device such as a power card. Also, the semiconductor element and the semiconductor device are used to make a semiconductor system.
    Type: Application
    Filed: January 11, 2021
    Publication date: July 15, 2021
    Inventors: Ryohei KANNO, Osamu IMAFUJI, Kazuyoshi NORIMATSU, Yuji KATO
  • Patent number: 10892597
    Abstract: A nitride semiconductor laser includes: a first nitride semiconductor layer; a light-emitting layer formed on the first nitride semiconductor layer and including a nitride semiconductor; a second nitride semiconductor layer formed on the light-emitting layer and having a ridge portion; an electrode component formed on the second nitride semiconductor layer, and which is wider than the ridge portion; and a dielectric layer formed on side surfaces of the ridge portion and including SiO2. A space is present between the electrode component and the dielectric layer, and the electrode component is prevented from being in contact with the dielectric layer by the space, and is in contact with the upper surface of the ridge portion.
    Type: Grant
    Filed: June 28, 2017
    Date of Patent: January 12, 2021
    Assignee: PANASONIC CORPORATION
    Inventors: Hiroyuki Hagino, Osamu Imafuji, Shinichiro Nozaki
  • Publication number: 20190245322
    Abstract: A nitride semiconductor laser includes: a first nitride semiconductor layer; a light-emitting layer formed on the first nitride semiconductor layer and including a nitride semiconductor; a second nitride semiconductor layer formed on the light-emitting layer and having a ridge portion; an electrode component formed on the second nitride semiconductor layer, and which is wider than the ridge portion; and a dielectric layer formed on side surfaces of the ridge portion and including SiO2. A space is present between the electrode component and the dielectric layer, and the electrode component is prevented from being in contact with the dielectric layer by the space, and is in contact with the upper surface of the ridge portion.
    Type: Application
    Filed: June 28, 2017
    Publication date: August 8, 2019
    Inventors: Hiroyuki HAGINO, Osamu IMAFUJI, Shinichiro NOZAKI
  • Patent number: 10141720
    Abstract: A nitride semiconductor laser element includes an electron barrier layer between a p-side light guide layer and a p-type clad layer. The electron barrier layer has a bandgap energy larger than that of the p-type clad layer. The p-side light guide layer is made of AlxGa1?xN containing no Indium, where 0?x<1. A film thickness dn of the n-side light guide layer and a film thickness dp of the p-side light guide layer satisfy relationships dp?0.25 ?m and dn?dp.
    Type: Grant
    Filed: January 9, 2018
    Date of Patent: November 27, 2018
    Assignee: PANASONIC CORPORATION
    Inventors: Masao Kawaguchi, Osamu Imafuji, Shinichiro Nozaki, Hiroyuki Hagino
  • Publication number: 20180131161
    Abstract: A nitride semiconductor laser element includes an electron barrier layer between a p-side light guide layer and a p-type clad layer. The electron barrier layer has a bandgap energy larger than that of the p-type clad layer. The p-side light guide layer is made of AlxGa1?xN containing no Indium, where 0 ?x<1. A film thickness dn of the n-side light guide layer and a film thickness dp of the p-side light guide layer satisfy relationships dp?0.25 ?m and dn?dp.
    Type: Application
    Filed: January 9, 2018
    Publication date: May 10, 2018
    Inventors: MASAO KAWAGUCHI, Osamu Imafuji, Shinichiro Nozaki, Hiroyuki Hagino
  • Patent number: 7301979
    Abstract: A semiconductor laser device of the present invention includes: a first conductivity type cladding layer; an active layer; and a second conductivity type cladding layer, which are on a substrate. The semiconductor laser device further includes a stripe structure for injecting carriers therein. A width of the stripe is wider at a front end face of a resonator from which laser light is emitted than at a rear end face that is located on an opposite side of the front end face, and a reflectance of the front end face is lower than a reflectance of the rear end face. With this configuration, the injection of carriers into an active layer can be controlled in accordance with an optical intensity distribution along the resonator direction within the semiconductor laser, thus achieving a decrease in threshold current, an enhancement of a slope efficiency and an enhancement of a kink level.
    Type: Grant
    Filed: April 14, 2004
    Date of Patent: November 27, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keiji Ito, Isao Kidoguchi, Toru Takayama, Osamu Imafuji
  • Patent number: 6909733
    Abstract: A semiconductor laser device comprises, on top of an active layer, an n-type cladding layer of Alx1Ga1?x1As and a p-type cladding layer of (AlxGa1?x)yIn1?yP for defining a barrier height. The p-type cladding layer for defining a barrier height contains more component elements than the n-type cladding layer. The potential difference between the conduction band edges of the p-type cladding layer for defining a barrier height and the active layer is greater than the potential difference between the conduction band edges of the n-type cladding layer and the active layer. The carriers in the active layer are prevented from overflowing into the p-type cladding layer and a material having a high thermal conductivity is used for the n-type cladding layer to prevent the phenomenon of thermal saturation, thereby providing improved optical output.
    Type: Grant
    Filed: October 3, 2001
    Date of Patent: June 21, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Katsuya Samonji, Toru Takayama, Osamu Imafuji, Masaaki Yuri
  • Patent number: 6888870
    Abstract: A semiconductor laser has a first conduction-type cladding layer, an active layer, and a second conduction-type cladding layer formed on a first conduction-type semiconductor substrate. The second conduction-type cladding layer has a mesa-type stripe-shaped recessed portion in at least four spots, so as to form a central ridge portion, which constitutes a ridge-type current confinement portion, and two or more lateral ridge portions, which are positioned on both sides of the central ridge portion, have a height larger than to that of the central ridge portion, and include the second conduction-type cladding layer. An insulation film with a lower refractive index than the second conduction-type cladding layer is formed in a pair of stripes disposed respectively in the regions from the side surface of the second conduction-type cladding layer on both side surfaces of the central ridge portion toward the outside. The insulation film is not formed on the central ridge portion.
    Type: Grant
    Filed: July 31, 2002
    Date of Patent: May 3, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Koji Makita, Hideto Adachi, Toshiya Kawata, Hiroshi Asaka, Osamu Imafuji, Toshiya Fukuhisa, Akira Takamori
  • Publication number: 20050035359
    Abstract: A substrate includes: a crystalline substrate including a primary surface and a crystal plane provided within the primary surface so as to have a surface orientation different from a surface orientation of the primary surface; a semiconductor layered structure grown over the crystalline substrate; and an active region provided at a portion in the semiconductor layer structure above the crystal plane.
    Type: Application
    Filed: September 30, 2004
    Publication date: February 17, 2005
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Masahiro ISHIDA, Shinji NAKAMURA, Kenji ORITA, Osamu IMAFUJI, Masaaki YURI
  • Publication number: 20040233957
    Abstract: A semiconductor laser device of the present invention includes: a first conductivity type cladding layer; an active layer; and a second conductivity type cladding layer, which are on a substrate. The semiconductor laser device further includes a stripe structure for injecting carriers therein. A width of the stripe is wider at a front end face of a resonator from which laser light is emitted than at a rear end face that is located on an opposite side of the front end face, and a reflectance of the front end face is lower than a reflectance of the rear end face. With this configuration, the injection of carriers into an active layer can be controlled in accordance with an optical intensity distribution along the resonator direction within the semiconductor laser, thus achieving a decrease in threshold current, an enhancement of a slope efficiency and an enhancement of a kink level.
    Type: Application
    Filed: April 14, 2004
    Publication date: November 25, 2004
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Keiji Ito, Isao Kidoguchi, Toru Takayama, Osamu Imafuji
  • Patent number: 6821805
    Abstract: Disclosed is a semiconductor device which comprises a substrate in which surface is formed a depression having a closed figure when viewed from the substrate normal and a semiconductor layer which is formed on the surface of the substrate by crystal growth from at least an inside face of the depression.
    Type: Grant
    Filed: October 5, 2000
    Date of Patent: November 23, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shinji Nakamura, Masahiro Ishida, Kenji Orita, Osamu Imafuji, Masaaki Yuri