Patents by Inventor Mitsuhiro Kushibe

Mitsuhiro Kushibe 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: 8039830
    Abstract: A semiconductor light emitting device includes a first layer made of at least one of n-type GaN and n-type AlGaN; a second layer made of Mg-containing p-type AlGaN; and a light emitting section provided between the first layer and the second layer. The light emitting section included a plurality of barrier layers made of Si-containing AlxGa1-x-yInyN (0?x, 0?y, x+y?1), and a well layer provided between each pair of the plurality of barrier layers and made of GaInN or AlGaInN. The plurality of barrier layers have a nearest barrier layer and a far barrier layer. The nearest barrier layer is nearest to the second layer among the plurality of barrier layers. The nearest barrier layer includes a first portion and a second portion. The first portion is made of Si-containing AlxGa1-x-yInyN (0?x, 0?y, x+y?1). The second portion is provided between the first portion and the second layer and is made of AlxGa1-x-yInyN (0?x, 0?y, x+y?1).
    Type: Grant
    Filed: July 17, 2009
    Date of Patent: October 18, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kei Kaneko, Yasuo Ohba, Hiroshi Katsuno, Mitsuhiro Kushibe
  • Publication number: 20110227033
    Abstract: According to one embodiment, a semiconductor light emitting device includes a first layer, a second layer, and a light emitting portion. The first layer includes at least one of n-type GaN and n-type AlGaN. The second layer includes p-type AlGaN. The light emitting portion has a single quantum well structure. The single quantum well structure includes a first barrier layer, a second barrier layer, and a well layer. The first barrier layer is provided between the first layer and the second layer and includes Alx1Ga1-x1-y1Iny1N (0<x1, 0?y1, x1+y1<1). The second barrier layer is provided between the first barrier layer and the second layer and includes Alx2Ga1-x2-y2Iny2N (0<x2, 0?y2, x2+y2<1). The well layer is provided between the first barrier layer and the second barrier layer, includes Alx0Ga1-x0-y0Iny0N (0?x0, 0<y0, x0+y0<1, y1<y0, y2<y0), and is configured to emit near ultraviolet light.
    Type: Application
    Filed: September 7, 2010
    Publication date: September 22, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Yasuo Ohba, Kei Kaneko, Hiroshi Katsuno, Shinji Yamada
  • Publication number: 20110220911
    Abstract: According to one embodiment, a semiconductor light-emitting device includes a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, a light-emitting layer, a third semiconductor layer and a first electrode. The light-emitting layer is provided between the first and second semiconductor layers. The third semiconductor layer is provided on opposite side of the first semiconductor layer from the light-emitting layer, has a lower impurity concentration than the first semiconductor layer, and includes an opening exposing part of the first semiconductor layer. The first electrode is in contact with the first semiconductor layer through the opening. The third semiconductor layer further includes a rough surface portion which is provided on opposite side from the first semiconductor layer and includes a surface asperity larger than wavelength in the third semiconductor layer of peak wavelength of emission light emitted from the light-emitting layer.
    Type: Application
    Filed: September 1, 2010
    Publication date: September 15, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Katsuno, Yasuo Ohba, Mitsuhiro Kushibe, Kei Kaneko, Shinji Yamada
  • Publication number: 20110220932
    Abstract: According to one embodiment, a semiconductor light-emitting device includes a first semiconductor layer, a second semiconductor layer, a light-emitting layer, a third semiconductor layer and a first electrode. The first semiconductor layer of a first conductivity type has a first major surface provided with a first surface asperity. The second semiconductor layer of a second conductivity type is provided on an opposite side of the first semiconductor layer from the first major surface. The light-emitting layer is provided between the first and second semiconductor layers. The first semiconductor layer is disposed between a third semiconductor layer and the light-emitting layer. The third semiconductor layer has an impurity concentration lower than an impurity concentration of the first semiconductor layer, and includes an opening exposing the first surface asperity.
    Type: Application
    Filed: September 1, 2010
    Publication date: September 15, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Katsuno, Yasuo Ohba, Mitsuhiro Kushibe, Kei Kaneko, Shinji Yamada
  • Publication number: 20110049550
    Abstract: A semiconductor light emitting element, includes: a laminated structure body including an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting layer; a p-side electrode provided in contact with the p-type semiconductor layer; an n-side electrode provided in contact with the n-type semiconductor layer; a highly reflective insulating layer provided in contact with the n-type semiconductor layer and having a higher reflectance than a reflectance of the n-side electrode; and an upper metal layer provided on at least a part of the n-side electrode and on at least a part of the highly reflective insulating layer and electrically connected to the n-side electrode. An area of a region of the n-side electrode in contact with the n-type semiconductor layer is smaller than an area of a region of the highly reflective insulating layer sandwiched between the n-type semiconductor layer and the upper metal layer.
    Type: Application
    Filed: March 5, 2010
    Publication date: March 3, 2011
    Inventors: Hiroshi Katsuno, Yasuo Ohba, Kei Kaneko, Mitsuhiro Kushibe
  • Publication number: 20110049541
    Abstract: A semiconductor light emitting device, includes: a stacked structural unit including a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, and a light emitting layer provided therebetween; and an electrode including a first and second metal layers, the first metal layer including silver or silver alloy and being provided on a side of the second semiconductor layer opposite to the light emitting layer, the second metal layer including at least one element selected from gold, platinum, palladium, rhodium, iridium, ruthenium, and osmium and being provided on a side of the first metal layer opposite to the second semiconductor layer. A concentration of the element in a region including an interface between the first and second semiconductor layers is higher than that of the element in a region of the first metal layer distal to the interface.
    Type: Application
    Filed: March 8, 2010
    Publication date: March 3, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroshi Katsuno, Yasuo Ohba, Kei Kaneko, Mitsuhiro Kushibe
  • Patent number: 7830937
    Abstract: It makes possible to inject a current into the current confinement region substantially uniformly. A surface emitting type optical semiconductor device includes a semiconductor active layer provided above a substrate; a first and second reflecting mirror layers sandwiching the semiconductor active layer to form an optical cavity in a direction perpendicular to the substrate; a plurality of current confinement regions provided in the second reflecting mirror layer so as to be separated by an impurity region having impurities; a semiconductor current diffusion layer provided on the second reflecting mirror layer so as to cover the current confinement regions; and an electrode portion which injects a current into the semiconductor active layer. The electrode portion comprising a first electrode provided on the semiconductor current diffusion layer so as to surround the current confinement regions and a second electrode provided on an opposite side of the substrate from the semiconductor active layer.
    Type: Grant
    Filed: August 13, 2008
    Date of Patent: November 9, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Mizunori Ezaki, Rei Hashimoto, Michihiko Nishigaki
  • Publication number: 20100059734
    Abstract: A semiconductor light emitting device includes a first layer made of at least one of n-type GaN and n-type AlGaN; a second layer made of Mg-containing p-type AlGaN; and a light emitting section provided between the first layer and the second layer. The light emitting section included a plurality of barrier layers made of Si-containing AlxGa1?x?yInyN (0?x, 0?y, x+y?1), and a well layer provided between each pair of the plurality of barrier layers and made of GaInN or AlGaInN. The plurality of barrier layers have a nearest barrier layer and a far barrier layer. The nearest barrier layer is nearest to the second layer among the plurality of barrier layers. The nearest barrier layer includes a first portion and a second portion. The first portion is made of Si-containing AlxGa1?x?yInyN (0?x, 0?y, x+y?1). The second portion is provided between the first portion and the second layer and is made of AlxGa1?x?yInyN (0?x, 0?y, x+y?1).
    Type: Application
    Filed: July 17, 2009
    Publication date: March 11, 2010
    Inventors: Kei KANEKO, Yasuo OHBA, Hiroshi KATSUNO, Mitsuhiro Kushibe
  • Publication number: 20100051994
    Abstract: A semiconductor light emitting device, includes: a stacked structure unit including a first semiconductor layer, a second semiconductor layer, and a light emitting layer provided between the first semiconductor layer and the second semiconductor layer; a first electrode provided on a first major surface of the stacked structure unit on the second semiconductor layer side to connect to the first semiconductor layer; and a second electrode provided on the first major surface of the stacked structure unit to connect to the second semiconductor layer. The second electrode includes: a first film provided on the second semiconductor layer; and a second film provided on a rim of the first film on the second semiconductor layer. The first film has a relatively low contact resistance with the second semiconductor layer. The second film has a relatively high contact resistance with the second semiconductor layer.
    Type: Application
    Filed: August 27, 2009
    Publication date: March 4, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroshi KATSUNO, Yasuo Ohba, Kei Kaneko, Mitsuhiro Kushibe
  • Publication number: 20100051995
    Abstract: A method for manufacturing a semiconductor light emitting apparatus includes causing a semiconductor light emitting device and a mounting member to face each other.
    Type: Application
    Filed: August 27, 2009
    Publication date: March 4, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroshi KATSUNO, Yasuo OHBA, Kei KANEKO, Mitsuhiro KUSHIBE
  • Publication number: 20100051987
    Abstract: A semiconductor light-emitting device includes: a laminated structure, a first electrode, a second electrode and a dielectric laminated film. The laminated structure includes, a first semiconductor layer, a second semiconductor layer, and a light-emitting layer provided between the first semiconductor layer and the second semiconductor layer, in which the second semiconductor layer and the light-emitting layer are selectively removed and a part of the first semiconductor layer is exposed to a first main surface on the side of the second semiconductor layer.
    Type: Application
    Filed: March 9, 2009
    Publication date: March 4, 2010
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Katsuno, Yasuo Ohba, Kei Kaneko, Mitsuhiro Kushibe
  • Publication number: 20100055819
    Abstract: A method for manufacturing a semiconductor light emitting device is provided. The device includes: an n-type semiconductor layer; a p-type semiconductor layer; and a light emitting unit provided between the n-type semiconductor layer and the p-type semiconductor layer. The method includes: forming a buffer layer made of a crystalline AlxGa1-xN (0.8?x?1) on a first substrate made of c-plane sapphire and forming a GaN layer on the buffer layer; stacking the n-type semiconductor layer, the light emitting unit, and the p-type semiconductor layer on the GaN layer; and separating the first substrate by irradiating the GaN layer with a laser having a wavelength shorter than a bandgap wavelength of GaN from the first substrate side through the first substrate and the buffer layer.
    Type: Application
    Filed: July 22, 2009
    Publication date: March 4, 2010
    Inventors: Yasuo OHBA, Kei Kaneko, Toru Gotoda, Hiroshi Katsuno, Mitsuhiro Kushibe
  • Publication number: 20100051978
    Abstract: A semiconductor light emitting device includes: a laminated structure body including an n-type semiconductor layer, a p-type semiconductor layer and a light emitting layer provided between the n-type semiconductor layer and the p-type semiconductor layer; a first electrode connected to the n-type semiconductor layer and containing at least one of silver and a silver alloy; and a second electrode connected to the p-type semiconductor layer.
    Type: Application
    Filed: March 9, 2009
    Publication date: March 4, 2010
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi KATSUNO, Yasuo Ohba, Kei Kaneko, Mitsuhiro Kushibe
  • Publication number: 20080317081
    Abstract: It makes possible to inject a current into the current confinement region substantially uniformly. A surface emitting type optical semiconductor device includes a semiconductor active layer provided above a substrate; a first and second reflecting mirror layers sandwiching the semiconductor active layer to form an optical cavity in a direction perpendicular to the substrate; a plurality of current confinement regions provided in the second reflecting mirror layer so as to be separated by an impurity region having impurities; a semiconductor current diffusion layer provided on the second reflecting mirror layer so as to cover the current confinement regions; and an electrode portion which injects a current into the semiconductor active layer. The electrode portion comprising a first electrode provided on the semiconductor current diffusion layer so as to surround the current confinement regions and a second electrode provided on an opposite side of the substrate from the semiconductor active layer.
    Type: Application
    Filed: August 13, 2008
    Publication date: December 25, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Mitsuhiro Kushibe, Mizunori Ezaki, Rei Hashimoto, Michihiko Nishigaki
  • Patent number: 7426228
    Abstract: It makes possible to inject a current into the current confinement region substantially uniformly. A surface emitting type optical semiconductor device includes a semiconductor active layer provided above a substrate; a first and second reflecting mirror layers sandwiching the semiconductor active layer to form an optical cavity in a direction perpendicular to the substrate; a plurality of current confinement regions provided in the second reflecting mirror layer so as to be separated by an impurity region having impurities; a semiconductor current diffusion layer provided on the second reflecting mirror layer so as to cover the current confinement regions; and an electrode portion which injects a current into the semiconductor active layer. The electrode portion comprising a first electrode provided on the semiconductor current diffusion layer so as to surround the current confinement regions and a second electrode provided on an opposite side of the substrate from the semiconductor active layer.
    Type: Grant
    Filed: March 23, 2006
    Date of Patent: September 16, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Mizunori Ezaki, Rei Hashimoto, Michihiko Nishigaki
  • Patent number: 7276735
    Abstract: A low-cost high-property optical semiconductor element for a long wavelength is provided, using a GaAs substrate. The optical semiconductor element comprises a substrate of GaAs having a first surface and a second surface opposite to each other, a buffer layer of InjGa1-jAs1-kNk (0?j?1, 0.002?k?0.05) formed on the first surface of the substrate, a first conductive type clad layer formed on the buffer layer, an active layer formed on the first conductive type clad layer and comprising a well layer of InzGa1-zAs (0?z?1), the well layer having a smaller bandgap than the first conductive type clad layer, the active layer having a thickness of more than its critical thickness for the substrate based upon equilibrium theories, and a second conductive type clad layer formed on the active layer and having a larger bandgap than the well layer.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: October 2, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Yasuo Ohba, Rei Hashimoto, Keiji Takaoka
  • Publication number: 20070047607
    Abstract: It makes possible to inject a current into the current confinement region substantially uniformly. A surface emitting type optical semiconductor device includes a semiconductor active layer provided above a substrate; a first and second reflecting mirror layers sandwiching the semiconductor active layer to form an optical cavity in a direction perpendicular to the substrate; a plurality of current confinement regions provided in the second reflecting mirror layer so as to be separated by an impurity region having impurities; a semiconductor current diffusion layer provided on the second reflecting mirror layer so as to cover the current confinement regions; and an electrode portion which injects a current into the semiconductor active layer. The electrode portion comprising a first electrode provided on the semiconductor current diffusion layer so as to surround the current confinement regions and a second electrode provided on an opposite side of the substrate from the semiconductor active layer.
    Type: Application
    Filed: March 23, 2006
    Publication date: March 1, 2007
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Mizunori Ezaki, Rei Hashimoto, Michihiko Nishigaki
  • Publication number: 20060187997
    Abstract: It is made possible to obtain high performance having high controllability in polarization mode even when a vertical cavity surface emitting laser diode is fabricated on an ordinary substrate with a plane orientation (100) plane or the like. A vertical cavity surface emitting laser diode includes: a substrate; a semiconductor active layer which is formed on the substrate and has a light emitting region; a first reflecting mirror and a second reflecting mirror sandwiching the semiconductor active layer; a first recess which has a first groove depth penetrating at least the semiconductor active layer from the outermost layer of the first reflecting mirror; a second recess having a second groove depth shallower than the first groove depth; a mesa portion which is surrounded by the first and second recesses; and an insulating film which is buried in the first recess.
    Type: Application
    Filed: January 13, 2006
    Publication date: August 24, 2006
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Mizunori Ezaki, Mitsuhiro Kushibe, Michihiko Nishigaki, Keiji Takaoka
  • Publication number: 20040245536
    Abstract: A low-cost high-property optical semiconductor element for a long wavelength is provided, using a GaAs substrate. The optical semiconductor element comprises a substrate of GaAs having a first surface and a second surface opposite to each other, a buffer layer of InjGa1-jAs1-kNk (0≦j≦1, 0.002≦k≦0.05) formed on the first surface of the substrate, a first conductive type clad layer formed on the buffer layer, an active layer formed on the first conductive type clad layer and comprising a well layer of InzGa1-zAs (0≦z≦1), the well layer having a smaller bandgap than the first conductive type clad layer, the active layer having a thickness of more than its critical thickness for the substrate based upon equilibrium theories, and a second conductive type clad layer formed on the active layer and having a larger bandgap than the well layer.
    Type: Application
    Filed: July 2, 2004
    Publication date: December 9, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Yasuo Ohba, Rei Hashimoto, Keiji Takaoka
  • Patent number: 6768137
    Abstract: A low-cost high-property optical semiconductor element for a long wavelength is provided, using a GaAs substrate. The optical semiconductor element comprises a substrate of GaAs having a first surface and a second surface opposite to each other, a buffer layer of InjGa1-jAs1-kNk (0≦j≦1, 0.002≦k≦0.05) formed on the first surface of the substrate, a first conductive type clad layer formed on the buffer layer, an active layer formed on the first conductive type clad layer and comprising a well layer of InzGa1-zAs (0≦z≦1), the well layer having a smaller bandgap than the first conductive type clad layer, the active layer having a thickness of more than its critical thickness for the substrate based upon equilibrium theories, and a second conductive type clad layer formed on the active layer and having a larger bandgap than the well layer.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: July 27, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Yasuo Ohba, Rei Hashimoto, Keiji Takaoka