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).
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Publication number: 20110312117Abstract: 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: ApplicationFiled: March 4, 2011Publication date: December 22, 2011Applicant: Kabushiki Kaisha ToshibaInventors: Aya SUZUKI, Kazuhiro Akiyama, Toshihide Izumiya
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Publication number: 20040227142Abstract: 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: ApplicationFiled: March 12, 2004Publication date: November 18, 2004Applicant: Kabushiki Kaisha ToshibaInventor: Toshihide Izumiya
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Patent number: 5822349Abstract: 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: GrantFiled: March 12, 1996Date of Patent: October 13, 1998Assignee: Kabushiki Kaisha ToshibaInventors: Keiji Takaoka, Mitsuhiro Kushibe, Toshihide Izumiya, Yoshihiro Kokubun
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Patent number: 5317167Abstract: 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: GrantFiled: May 10, 1993Date of Patent: May 31, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Toshihide Izumiya, Yasuo Ohba, Ako Hatano
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Patent number: 5273933Abstract: 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: GrantFiled: July 23, 1992Date of Patent: December 28, 1993Assignee: Kabushiki Kaisha ToshibaInventors: Ako Hatano, Toshihide Izumiya, Yasuo Ohba
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Patent number: 5235194Abstract: 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: GrantFiled: January 13, 1992Date of Patent: August 10, 1993Assignee: Kabushiki Kaisha ToshibaInventors: Toshihide Izumiya, Yasuo Ohba, Ako Hatano
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Patent number: 5103271Abstract: 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: GrantFiled: September 27, 1990Date of Patent: April 7, 1992Assignee: Kabushiki Kaisha ToshibaInventors: Toshihide Izumiya, Yasuo Ohba, Ako Hatano
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Patent number: 5079184Abstract: 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: GrantFiled: June 15, 1990Date of Patent: January 7, 1992Assignee: Kabushiki Kaisha ToshibaInventors: Ako Hatano, Toshihide Izumiya, Yasuo Ohba
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Patent number: 5076860Abstract: 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: GrantFiled: September 29, 1989Date of Patent: December 31, 1991Assignee: Kabushiki Kaisha ToshibaInventors: Yasuo Ohba, Toshihide Izumiya, Ako Hatano
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Patent number: 5042043Abstract: 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: GrantFiled: April 13, 1990Date of Patent: August 20, 1991Assignee: Kabushiki Kaisha ToshibaInventors: Ako Hatano, Toshihide Izumiya, Yasuo Ohba
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Patent number: 5005057Abstract: 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: GrantFiled: April 13, 1990Date of Patent: April 2, 1991Assignee: Kabushiki Kaisha ToshibaInventors: Toshihide Izumiya, Yasuo Ohba, Ako Hatano