Patents by Inventor Toyoharu Ohata

Toyoharu Ohata 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: 7319052
    Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.
    Type: Grant
    Filed: April 11, 2005
    Date of Patent: January 15, 2008
    Assignee: Sony Corporation
    Inventors: Katsuhiro Tomoda, Toyoharu Ohata
  • Patent number: 7049227
    Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.
    Type: Grant
    Filed: April 11, 2005
    Date of Patent: May 23, 2006
    Assignee: Sony Corporation
    Inventors: Katsuhiro Tomoda, Toyoharu Ohata
  • Patent number: 7011990
    Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.
    Type: Grant
    Filed: April 11, 2005
    Date of Patent: March 14, 2006
    Assignee: Sony Corporation
    Inventors: Katsuhiro Tomoda, Toyoharu Ohata
  • Patent number: 7008827
    Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.
    Type: Grant
    Filed: April 11, 2005
    Date of Patent: March 7, 2006
    Assignee: Sony Corporation
    Inventors: Katsuhiro Tomoda, Toyoharu Ohata
  • Publication number: 20050181603
    Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.
    Type: Application
    Filed: April 11, 2005
    Publication date: August 18, 2005
    Inventors: Katsuhiro Tomoda, Toyoharu Ohata
  • Publication number: 20050181602
    Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.
    Type: Application
    Filed: April 11, 2005
    Publication date: August 18, 2005
    Inventors: Katsuhiro Tomoda, Toyoharu Ohata
  • Publication number: 20050181601
    Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer, by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.
    Type: Application
    Filed: April 11, 2005
    Publication date: August 18, 2005
    Inventors: Katsuhiro Tomoda, Toyoharu Ohata
  • Publication number: 20050176190
    Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.
    Type: Application
    Filed: April 11, 2005
    Publication date: August 11, 2005
    Inventors: Katsuhiro Tomoda, Toyoharu Ohata
  • Patent number: 6878574
    Abstract: An alloying method includes steps of forming a metal layer on a semiconductor that is then transferred to a material having a low thermal conductivity. An interface between the semiconductor and the metal layer is formed into an alloy by irradiating the interface with a laser beam having a wavelength that is absorbable in at least one of the semiconductor and the metal layer. Preferably, the material having a low thermal conductivity is a resin or amorphous silicon. Because the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effects on the characteristics of the semiconductor device.
    Type: Grant
    Filed: January 14, 2003
    Date of Patent: April 12, 2005
    Assignee: Sony Corporation
    Inventors: Katsuhiro Tomoda, Toyoharu Ohata
  • Publication number: 20030170971
    Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.
    Type: Application
    Filed: January 14, 2003
    Publication date: September 11, 2003
    Inventors: Katsuhiro Tomoda, Toyoharu Ohata
  • Patent number: 5640409
    Abstract: A semiconductor light-emitting device capable of emitting blue to green light is disclosed. The device comprises a first cladding layer of the first conduction type stacked on a compound semiconductor substrate and made of ZnMgSSe compound semiconductor; an active layer stacked on the first cladding layer; a second cladding layer of the second conduction type stacked on the active layer and made of a ZnMgSSe compound semiconductor; and ZnSSe compound semiconductor layers provided on the second cladding layer and/or between the compound semiconductor substrate and the first cladding layer. The device has good optical confinement characteristics and carrier confinement characteristics, generates only a small amount of heat during its operation, and is fabricated easily.
    Type: Grant
    Filed: January 25, 1996
    Date of Patent: June 17, 1997
    Assignee: Sony Corporation
    Inventors: Satoshi Ito, Toyoharu Ohata, Akira Ishibashi, Norikazu Nakayama
  • Patent number: 5515393
    Abstract: A semiconductor laser using a II-VI compound semiconductor as the material for cladding layers, capable of emitting a blue to green light is disclosed. In an aspect of the semiconductor laser, an n-type ZnSe buffer layer, an n-type ZnMgSSe cladding layer, an active layer made of, for example, ZnCdSe, a p-type ZnMgSSe cladding layer and a p-type ZnSe contact layer are stacked in sequence on an n-type GaAs substrate. A p-side electrode such as an Au/Pd electrode is provided in contact with the p-type ZnSe contact layer. An n-side electrode such as an In electrode is provided on the back surface of the n-type GaAs substrate. In another aspect of the semiconductor laser, an n-type optical guiding layer made of ZnSSe, ZnMgSSe or ZnSe is provided between the n-type ZnMgSSe cladding layer and the active layer, and a p-type optical guiding layer made of ZnSSe, ZnMgSSe or ZnSe is provided between the p-type ZnMgSSe cladding layer and the active layer.
    Type: Grant
    Filed: August 4, 1993
    Date of Patent: May 7, 1996
    Assignee: Sony Corporation
    Inventors: Hiroyuki Okuyama, Katsuhiro Akimoto, Takao Miyajima, Masafumi Ozawa, Yuko Morinaga, Futoshi Hiei, Kazushi Nakano, Toyoharu Ohata
  • Patent number: 5481558
    Abstract: According to the present invention, a p-type ZnSe or p-type ZnSSe buffer layer is formed on a p-type GaAs substrate through at least single layer made of AlGaInP-based material and a II/VI-compound laser structure is formed on the p-type ZnSe or p-type ZnSSe buffer layer. Further, an AlGaAs-based buffer layer is provided between the substrate and the AlGaInP-based buffer layer. Further, the AlGaAs-based buffer layer has a composition expressed as Al.sub.0.5 Ga.sub.0.4 As and the AlGaInP-based buffer layer has a composition expressed as Al.sub.0.5 In.sub.0.5 P. Furthermore, a composition ratio x of Al in a buffer layer expressed as Al.sub.x Ga.sub.1-x As is modulated from 0 to 0.6 and a composition ratio y of Al in a buffer layer expressed as (Al.sub.y Ga.sub.1-y).sub.0.5 In.sub.0.5 P is modulated from 0 to 1. According to the present invention, an operation voltage of the II/VI-compound semiconductor laser can be reduced and the green or blue color semiconductor laser of low operation voltage can be obtained.
    Type: Grant
    Filed: June 14, 1994
    Date of Patent: January 2, 1996
    Assignee: Sony Corporation
    Inventors: Masao Ikeda, Toyoharu Ohata
  • Patent number: 5379314
    Abstract: A light emitting element comprises a substrate having a {100} crystal face having a ridge extending in a <001> crystal axis direction, a first cladding layer formed on the ridge, an active layer formed on the first cladding layer, a second cladding layer formed on the active layer, a first electrode being electrically connected to the substrate, and a second electrode being electrically connected to the second cladding layer.
    Type: Grant
    Filed: October 20, 1993
    Date of Patent: January 3, 1995
    Assignee: Sony Corporation
    Inventors: Kazuhiko Nemoto, Toyoharu Ohata, Masamichi Ogawa
  • Patent number: 5373173
    Abstract: A light emitting element having a semiconductor substrate having {100} crystal surface as a major surface, a light emitting element formed on the semiconductor substrate, a growth blocking layer formed on a resonator end face of the light emitting element, a regrown layer formed on the light emitting element, a reflection mirror opposed to the resonator end face, a first electrode in contact with said semiconductor substrate, and a second electrode formed on the regrown layer, in which the regrown layer is made of the same material as that of the reflection mirror and the reflection mirror is formed of a semiconductor formed of {110} crystal surface epitaxially grown.
    Type: Grant
    Filed: May 18, 1993
    Date of Patent: December 13, 1994
    Assignee: Sony Corporation
    Inventors: Toyoharu Ohata, Masamichi Ogawa, Kazuhiko Nemoto, Yoshifumi Mori
  • Patent number: 5331659
    Abstract: An optical semiconductor device in which both of positive input and negative input are possible is disclosed. In the optical semiconductor device, two heterojunction phototransistors are connected in parallel of each other to the cathode of a laser diode. An optical memory in which setting, i.e., writing and resetting, i.e., erasing by light are possible is also disclosed. In the optical memory, two heterojunction phototransistors are connected in parallel of each other to the cathode of a laser diode to make a memory cell.
    Type: Grant
    Filed: March 11, 1993
    Date of Patent: July 19, 1994
    Assignee: Sony Corporation
    Inventors: Toyoharu Ohata, Kazuhiko Nemoto, Masamichi Ogawa