Patents by Inventor Toshihide Izumiya

Toshihide Izumiya 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: 20110312117
    Abstract: According to one embodiment, a method is disclosed for manufacturing a semiconductor light emitting device. The method can include forming an active layer including indium (In) on a heated substrate. The method can include forming a multiple-layer film made of a nitride semiconductor on the active layer in a state of the substrate being heated to substantially the same temperature as a temperature of the forming of the active layer. In addition, the method can include cooling the substrate to room temperature after the forming of the multiple-layer film.
    Type: Application
    Filed: March 4, 2011
    Publication date: December 22, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Aya SUZUKI, Kazuhiro Akiyama, Toshihide Izumiya
  • Publication number: 20040227142
    Abstract: A light-emitting semiconductor device is made of a first reflection film, an active layer, a second reflection film, an electric current spreading layer, a contact layer, and a high resistance region in order. The first reflection film reflects light with a wavelength &lgr;. The active layer is injected with electric current to emit light with a wavelength of about &lgr;. The second reflection film reflects the light with the wavelength &lgr;. The second reflection film has a periodical structure alternately stacked with a first semiconductor layer and a second semiconductor layer. A reflectivity with respect to the light with the wavelength &lgr; of the second reflection film is lower than that of said first reflection film. The electric current spreading layer transmits the light with the wavelength &lgr;. The electric current spreading layer is the same electronic conduction type as the second reflection film and has not less than half of a thickness of the second reflection film.
    Type: Application
    Filed: March 12, 2004
    Publication date: November 18, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Toshihide Izumiya
  • Patent number: 5822349
    Abstract: This invention is a semiconductor device including a p-type InP substrate having a mesa stripe in which at least an active layer and an n-type cladding layer are formed, and a semiconductor layer so formed as to bury the side surfaces of the mesa stripe and having at least an n-type current blocking layer and a p-type current blocking layer, wherein the n-type current blocking layer contains approximately 8.times.10.sup.17 cm.sup.-3 or more of Se as an impurity and the n-type current blocking layer and the n-type cladding layer are not contacting each other.
    Type: Grant
    Filed: March 12, 1996
    Date of Patent: October 13, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Keiji Takaoka, Mitsuhiro Kushibe, Toshihide Izumiya, Yoshihiro Kokubun
  • Patent number: 5317167
    Abstract: A semiconductor light-emitting device comprises a light-emitting layer including a pn junction formed by a plurality of In.sub.x Ga.sub.y Al.sub.1-x-y P (0.ltoreq.x, y.ltoreq.1) layers, and a light-emitting-layer holding layer consisting of an indirect transition type Ga.sub.1-w Al.sub.w As (0.ltoreq.w.ltoreq.1) provided on an opposite side to a light-outputting side. The holding layer has a sufficiently small light absorption coefficient for the light from the light-emitting layer although its band gap is small and improves the light emission efficiency of the semiconductor light-emitting device.
    Type: Grant
    Filed: May 10, 1993
    Date of Patent: May 31, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshihide Izumiya, Yasuo Ohba, Ako Hatano
  • Patent number: 5273933
    Abstract: In a process of manufacturing a short-wavelength-light emitting element, n- and p-type GaInAlN films are formed on a substrate made of SiC, using an MOCVD method. (CH.sub.3).sub.3 SiN.sub.3 is used as raw material for nitrogen. The films are grown at a relatively low temperature and the amount of nitrogen doped in the films is increased.
    Type: Grant
    Filed: July 23, 1992
    Date of Patent: December 28, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ako Hatano, Toshihide Izumiya, Yasuo Ohba
  • Patent number: 5235194
    Abstract: A semiconductor light-emitting device comprises a light-emitting layer including a pn junction formed by a plurality of In.sub.x Ga.sub.y Al.sub.1-x-y P (0.ltoreq.x, y.ltoreq.1) layers, and a light-emitting-layer holding layer consisting of an indirect transition type Ga.sub.l-w Al.sub.w As (0.ltoreq.w.ltoreq.1) provided on an opposite side to a light-outputting side. The holding layer has a sufficiently small light absorption coefficient for the light from the light-emitting layer although its band gap is small and improves the light emission efficiency of the semiconductor light-emitting device.
    Type: Grant
    Filed: January 13, 1992
    Date of Patent: August 10, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshihide Izumiya, Yasuo Ohba, Ako Hatano
  • Patent number: 5103271
    Abstract: A semiconductor light-emitting device comprises a light-emitting layer including a pn junction formed by a plurality of In.sub.x Ga.sub.y Al.sub.l-x-y P (0.ltoreq.x, y.ltoreq.l) layers, and a light-emitting-layer holding layer consisting of an indirect transition type Ga.sub.l-w Al.sub.w As (0.ltoreq.w.ltoreq.l) provided on an opposite side to a light-outputting side. The holding layer has a sufficiently small light absorption coefficient for the light from the light-emitting layer even though its band gap is small and improves the light emission efficiency of the semiconductor light-emitting device.
    Type: Grant
    Filed: September 27, 1990
    Date of Patent: April 7, 1992
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshihide Izumiya, Yasuo Ohba, Ako Hatano
  • Patent number: 5079184
    Abstract: A magnesium-doped p-type III-V Group compound semiconductor layer can be formed by metal organic chemical vapor deposition, by reacting, in a vapor phase, at least one compound of a Group III element with at least one compound of a Group V element, in the presence of an adduct of an organic magnesium compound with another compound as a doping source of magnesium.
    Type: Grant
    Filed: June 15, 1990
    Date of Patent: January 7, 1992
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ako Hatano, Toshihide Izumiya, Yasuo Ohba
  • Patent number: 5076860
    Abstract: A compound semiconductor material includes Ga.sub.x Al.sub.1-x N (wherein 0.ltoreq.x.ltoreq.1) containing B and P and having a zinc blend type crystal structure. A compound semiconductor element includes Ga.sub.x Al.sub.1-x N (wherein 0.ltoreq.x.ltoreq.1) layer having a zinc blend type crystal structure. A method of manufacturing a compound semiconductor element includes the step of sequentially forming a BP layer and a Ga.sub.x Al.sub.1-x N (wherein 0.ltoreq.x.ltoreq.1) layer on a substrate so as to form a heterojunction by using a metal organic chemical vapor deposition apparatus having a plurality of reaction regions, and moving the substrate between the plurality of reaction regions.
    Type: Grant
    Filed: September 29, 1989
    Date of Patent: December 31, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuo Ohba, Toshihide Izumiya, Ako Hatano
  • Patent number: 5042043
    Abstract: A green light-emitting semiconductor laser using a superlattice layer wherein BP layers and Ga.sub.x Al.sub.1-x N (0.ltoreq.x.ltoreq.1) layers are alternately stacked and each of the Ga.sub.x Al.sub.1-x N (0.ltoreq.x.ltoreq.1) layers has a zinc blende type crystal structure, or a Ga.sub.x Al.sub.y B.sub.1-x-y N.sub.z P.sub.1-z (0.ltoreq.x, y, z.ltoreq.1) mixed crystal layers with a zinc blende type structure a first clad layer of a first conductivity type, an active layer, and a second clad layer of a second conductivity type, together constituting a double heterojunction.
    Type: Grant
    Filed: April 13, 1990
    Date of Patent: August 20, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ako Hatano, Toshihide Izumiya, Yasuo Ohba
  • Patent number: 5005057
    Abstract: A blue LED which includes a light-emitting layer having a p-n junction makes use of the superlattice structure being formed of a plurality of BP layers and Ga.sub.x Al.sub.1-x N (0.ltoreq.x.ltoreq.1) layers which are alternately stacked, with the Ga.sub.x Al.sub.1-x N (0.ltoreq.x.ltoreq.1) layers having a zinc blende type structure, or else makes use of a Ga.sub.x Al.sub.y B.sub.1-x-y N.sub.z P.sub.1-z (0.ltoreq.x, y, z.ltoreq.1 and x+y.ltoreq.1) mixed crystal layer having a zinc blende type crystal structure.
    Type: Grant
    Filed: April 13, 1990
    Date of Patent: April 2, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshihide Izumiya, Yasuo Ohba, Ako Hatano