Patents by Inventor Shinya Asami

Shinya Asami 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: 20190237584
    Abstract: A semiconductor device includes a first oxide insulating layer over a first insulating layer, an oxide semiconductor layer over the first oxide insulating layer, a source electrode layer and a drain electrode layer over the oxide semiconductor layer, a second insulating layer over the source electrode layer and the drain electrode layer, a second oxide insulating layer over the oxide semiconductor layer, a gate insulating layer over the second oxide insulating layer, a gate electrode layer over the gate insulating layer, and a third insulating layer over the second insulating layer, the second oxide insulating layer, the gate insulating layer, and the gate electrode layer. A side surface portion of the second insulating layer is in contact with the second oxide insulating layer. The gate electrode layer includes a first region and a second region. The first region has a width larger than that of the second region.
    Type: Application
    Filed: April 9, 2019
    Publication date: August 1, 2019
    Inventors: Yoshinobu ASAMI, Yutaka OKAZAKI, Satoru OKAMOTO, Shinya SASAGAWA
  • Patent number: 7045809
    Abstract: A barrier layer made of AlxGa1?xN (0<x?0.18) is formed in a light-emitting semiconductor device using gallium nitride compound having a multi quantum-well (MQW) structure. By controlling a composition ratio x of aluminum (Al) or thickness of the barrier layer, luminous intensity of the device is improved. An n-cladding layer made of AlxGa1?xN (0<x?0.06) is formed in a light-emitting semiconductor device using gallium nitride compound. By controlling a composition ratio x of aluminum or thickness of the n-cladding layer, luminous intensity of the device is improved. A p-type layer and an n-type layer are formed in a light-emitting semiconductor device using gallium nitride compound having a double-hetero junction structure. By controlling a ratio of a hole concentration of the p-type layer and an electron concentration of the n-type layer approximates to 1, luminous intensity of the device is improved.
    Type: Grant
    Filed: August 6, 2003
    Date of Patent: May 16, 2006
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Hisaki Kato, Hiroshi Watanabe, Norikatsu Koide, Shinya Asami
  • Patent number: 7045829
    Abstract: A Group III nitride compound semiconductor includes a multiple layer structure having an emission layer between an n-type cladding layer and a p-type cladding layer. The n-type cladding layer may be below the emission layer, having been formed on another n-type layer which was formed over a buffer Layer and a sapphire substrate. The emission layer has a thickness which is wider than the diffusion length of holes within the emission layer. The n-type cladding layer is doped with a donor impurity and has a lattice constant Substantially equal to a lattice constant of the emission layer. The p-type cladding layer is doped with an acceptor impurity and has a forbidden band sufficiently wider than the forbidden band of the emission layer in ordor to confine electrons injected into the emission layer.
    Type: Grant
    Filed: July 23, 1996
    Date of Patent: May 16, 2006
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Masayoshi Koike, Shinya Asami
  • Patent number: 7030414
    Abstract: A Group III nitride compound semiconductor light-emitting device includes a multilayer having a quantum well structure containing an InGaN well layer and an AlGaN barrier layer. The film thickness, growth rate and growth temperature of the InGaN layer as the well layer and the film thickness of the AlGaN layer as the barrier layer are controlled to be optimized to thereby improve an output of the light-emitting device.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: April 18, 2006
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Shinya Asami, Hiroshi Watanabe, Jun Ito, Naoki Shibata
  • Patent number: 6982435
    Abstract: A group III nitride compound semiconductor device is produced according to the following manner. A separation layer made of a material which prevents group III nitride compound semiconductors from being grown thereon is formed on a substrate. Group III nitride compound semiconductors is grown on a surface of the substrate uncovered with the separation layer while keeping the uncovered substrate surface separated by the separation layer.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: January 3, 2006
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Naoki Shibata, Jun Ito, Toshiaki Chiyo, Shizuyo Asami, Hiroshi Watanabe, Shinya Asami
  • Patent number: 6939733
    Abstract: A first group III nitride compound layer, which is formed on a substrate by a method not using metal organic compounds as raw materials, is heated in an atmosphere of a mixture gas containing a hydrogen or nitrogen gas and an ammonia gas, so that the crystallinity of a second group III nitride compound semiconductor layer formed on the first group III nitride compound layer is improved. When the first group III nitride compound layer is formed on a substrate by a sputtering method, the thickness of the first group III nitride compound layer is set to be in a range of from 50 ? to 3000 ?.
    Type: Grant
    Filed: December 3, 2003
    Date of Patent: September 6, 2005
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Naoki Shibata, Jun Ito, Toshiaki Chiyo, Shizuyo Asami, Hiroshi Watanabe, Masanobu Senda, Shinya Asami
  • Patent number: 6918961
    Abstract: A group III nitride compound semiconductor device has a substrate and an AlN single crystal layer formed on the substrate. The AlN single crystal layer has a thickness of from 0.5 to 3 ?m and has a substantially flat surface. The half-value width of an X-ray rocking curve of the AlN single crystal layer is not longer than 50 sec. In another device, a group III nitride compound semiconductor layer having a thickness of from 0.01 to 3.2 ?m is grown at a temperature of from 1000 to 1180° C. on a sapphire substrate having a surface nitride layer having a thickness of not larger than 300 ?.
    Type: Grant
    Filed: April 24, 2003
    Date of Patent: July 19, 2005
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Toshiaki Chiyo, Naoki Shibata, Masanobu Senda, Jun Ito, Shizuyo Asami, Shinya Asami, Hiroshi Watanabe
  • Patent number: 6872965
    Abstract: An undercoat layer inclusive of a metal nitride layer is formed on a substrate. Group III nitride compound semiconductor layers are formed on the undercoat layer continuously.
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: March 29, 2005
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Jun Ito, Toshiaki Chiyo, Naoki Shibata, Hiroshi Watanabe, Shizuyo Asami, Shinya Asami
  • Patent number: 6853009
    Abstract: A barrier layer made of AlxGa1-xN (0<x?0.18) is formed in a light-emitting semiconductor device using gallium nitride compound having a multi quantum-well (MQW) structure. By controlling a composition ratio x of aluminum (Al) or thickness of the barrier layer, luminous intensity of the device is improved. An n-cladding layer made of AlxGa1-xN (0<x?0.06) is formed in a light-emitting semiconductor device using gallium nitride compound. By controlling a composition ratio x of aluminum or thickness of the n-cladding layer, luminous intensity of the device is improved. A p-type layer and an n-type layer are formed in a light-emitting semiconductor device using gallium nitride compound having a double-hetero junction structure. By controlling a ratio of a hole concentration of the p-type layer and an electron concentration of the n-type layer approximates to 1, luminous intensity of the device is improved.
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: February 8, 2005
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Hisaki Kato, Hiroshi Watanabe, Norikatsu Koide, Shinya Asami
  • Patent number: 6841808
    Abstract: An AlN layer having a surface of a texture structure is formed on a sapphire substrate. Then, a growth suppressing material layer is formed on the AlN layer so that the AlN layer is partially exposed to the outside. Then, group III nitride compound semiconductor layers are grown on the AlN layer and on the growth suppressing material layer by execution of an epitaxial lateral overgrowth method. Thus, a group III nitride compound semiconductor device is produced. An undercoat layer having convex portions each shaped like a truncated hexagonal pyramid is formed on a substrate. Group III nitride compound semiconductor layers having a device function are laminated successively on the undercoat layer.
    Type: Grant
    Filed: June 21, 2001
    Date of Patent: January 11, 2005
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Naoki Shibata, Toshiaki Chiyo, Masanobu Senda, Jun Ito, Hiroshi Watanabe, Shinya Asami, Shizuyo Asami
  • Patent number: 6838706
    Abstract: In a group III nitride compound semiconductor light-emitting device, a light-emitting layer having a portion where an InGaN layer is interposed between AlGaN layers on both sides thereof is employed. By controlling the thickness, growth rate and growth temperature of InGaN layer which is a well layer and the thickness of AlGaN layer which is a barrier layer so that they are optimized, the output of the light-emitting device is enhanced.
    Type: Grant
    Filed: July 3, 2001
    Date of Patent: January 4, 2005
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Hiroshi Watanabe, Jun Ito, Shinya Asami, Naoki Shibata
  • Patent number: 6821800
    Abstract: In a method of manufacturing a semiconductor light-emitting device involving the steps of: forming a first semiconductor layer; forming a light-emitting layer of superlattice structure by laminating a barrier layer being made of InY1Ga1-Y1N (Y1≧0) and a quantum well layer being made of InY2Ga1-Y2N (Y2>Y1 and Y2>0) on the first semiconductor layer; and forming a second semiconductor layer on the light-emitting layer, an uppermost barrier layer, which will become an uppermost layer of the light-emitting layer, is made thicker than the other barrier layers. Further, at the time of forming the second semiconductor layer, an upper surface of such uppermost barrier layer is caused to disappear so that the thickness of the uppermost barrier layer becomes substantially equal to those of the other barrier layers.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: November 23, 2004
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Norikatsu Koide, Shinya Asami, Junichi Umezaki, Masayoshi Koike, Shiro Yamasaki, Seiji Nagai
  • Publication number: 20040115917
    Abstract: A first group III nitride compound layer, which is formed on a substrate by a method not using metal organic compounds as raw materials, is heated in an atmosphere of a mixture gas containing a hydrogen or nitrogen gas and an ammonia gas, so that the crystallinity of a second group III nitride compound semiconductor layer formed on the first group III nitride compound layer is improved. When the first group III nitride compound layer is formed on a substrate by a sputtering method, the thickness of the first group III nitride compound layer is set to be in a range of from 50 Å to 3000 Å.
    Type: Application
    Filed: December 3, 2003
    Publication date: June 17, 2004
    Applicant: Toyoda Gosei Co., Ltd.
    Inventors: Naoki Shibata, Jun Ito, Toshiaki Chiyo, Shizuyo Asami, Hiroshi Watanabe, Masanobu Senda, Shinya Asami
  • Publication number: 20040113169
    Abstract: A Group III nitride compound semiconductor light-emitting device includes a multilayer having a quantum well structure containing an InGaN well layer and an AlGaN barrier layer. The film thickness, growth rate and growth temperature of the InGaN layer as the well layer and the film thickness of the AlGaN layer as the barrier layer are controlled to be optimized to thereby improve an output of the light-emitting device.
    Type: Application
    Filed: September 23, 2003
    Publication date: June 17, 2004
    Inventors: Shinya Asami, Hiroshi Watanabe, Jun Ito, Naoki Shibata
  • Patent number: 6713789
    Abstract: A first group III nitride compound layer, which is formed on a substrate by a method not using metal organic compounds as raw materials, is heated in an atmosphere of a mixture gas containing a hydrogen or nitrogen gas and an ammonia gas, so that the crystallinity of a second group III nitride compound semiconductor layer formed on the first group III nitride compound layer is improved. When the first group III nitride compound layer is formed on a substrate by a sputtering method, the thickness of the first group III nitride compound layer is set to be in a range of from 50 Å to 3000 Å.
    Type: Grant
    Filed: March 1, 2000
    Date of Patent: March 30, 2004
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Naoki Shibata, Jun Ito, Toshiaki Chiyo, Shizuyo Asami, Hiroshi Watanabe, Masanobu Senda, Shinya Asami
  • Publication number: 20040026705
    Abstract: A barrier layer made of AlxGa1-xN (0<x≦0.18) is formed in a light-emitting semiconductor device using gallium nitride compound having a multi quantum-well (MQW) structure. By controlling a composition ratio x of aluminum (Al) or thickness of the barrier layer, luminous intensity of the device is improved.
    Type: Application
    Filed: August 6, 2003
    Publication date: February 12, 2004
    Applicant: Toyoda Gosei Co., Ltd.
    Inventors: Hisaki Kato, Hiroshi Watanabe, Norikatsu Koide, Shinya Asami
  • Publication number: 20040018657
    Abstract: An emission layer (5) for a light source device is formed to have a multi-layer structure, doped with an acceptor and a donor impurity. The multi-layer structure may include a quantum well (QW) structure or a multi quantum well (MQW) structure (50). With such a structure, a peak wavelength of the light source can be controlled, because the distances between atoms of the acceptor and the donor impurities are widened. Several arrangements can be made by, e.g., altering the thickness of each composite layer of the multi-layer structure, altering their composition ratio, forming undoped layer 5 between the impurity doped layers, and so forth. Further, luminous intensity of ultra violet color can be improved, because doping the donor impurity and the acceptor impurity realizes a donor-acceptor emission mechanism and abundant carriers. Several arrangements can be made by, e.g.
    Type: Application
    Filed: July 14, 2003
    Publication date: January 29, 2004
    Applicant: Toyoda Gosei Co., Ltd.
    Inventors: Masayoshi Koike, Shinya Asami
  • Patent number: 6645785
    Abstract: An emission layer (5) for a light source device is formed to have a multi-layer structure, doped with an acceptor and a donor impurity. The multi-layer structure may include a quantum well (QW) structure or a multi quantum well (MQW) structure (50). With such a structure, a peak wavelength of the light source can be controlled, because the distances between atoms of the acceptor and the donor impurities are widened. Several arrangements can be made by, e.g., altering the thickness of each composite layer of the multi-layer structure, altering their composition ratio, forming undoped layer 5 between the impurity doped layers, and so forth. Further, luminous intensity of ultra violet color can be improved, because doping the donor impurity and the acceptor impurity realizes a donor-acceptor emission mechanism and abundant carriers. Several arrangements can be made by, e.g.
    Type: Grant
    Filed: July 23, 2001
    Date of Patent: November 11, 2003
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Masayoshi Koike, Shinya Asami
  • Publication number: 20030205195
    Abstract: A group III nitride compound semiconductor device has a substrate and an AlN single crystal layer formed on the substrate. The AlN single crystal layer has a thickness of from 0.5 to 3 &mgr;m and has a substantially flat surface. The half-value width of an X-ray rocking curve of the AlN single crystal layer is not longer than 50 sec. In another device, a group III nitride compound semiconductor layer having a thickness of from 0.01 to 3.2 &mgr;m is grown at a temperature of from 1000 to 1180° C. on a sapphire substrate having a surface nitride layer having a thickness of not larger than 300 Å.
    Type: Application
    Filed: April 24, 2003
    Publication date: November 6, 2003
    Applicant: TOYODA GOSEI CO., LTD.
    Inventors: Toshiaki Chiyo, Naoki Shibata, Masanobu Senda, Jun Ito, Shizuyo Asami, Shinya Asami, Hiroshi Watanabe
  • Publication number: 20030205718
    Abstract: A Group III nitride compound semiconductor includes a multiple layer structure having an emission layer between an n-type cladding layer and a p-type cladding layer. The n-type cladding layer may be below the emission layer, having been formed on another n-type layer which was formed over a buffer layer and a sapphire substrate. The emission layer has a thickness which is wider than the diffusion length of holes within the emission layer. The n-type cladding layer is doped with a donor impurity and has a lattice constant substantially equal to a lattice constant of the emission layer. The p-type cladding layer is doped with an acceptor impurity and has a forbidden band sufficiently wider than the forbidden band of the emission layer in order to confine electrons injected into the emission layer.
    Type: Application
    Filed: June 9, 2003
    Publication date: November 6, 2003
    Applicant: TOYODA GOSEI CO., LTD
    Inventors: Masayoshi Koike, Shinya Asami