Patents by Inventor Tokuhiko Matsunaga
Tokuhiko Matsunaga 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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Patent number: 9472713Abstract: An embodiment has an emission layer, a first electrode having a reflective metal layer, an insulating layer, first and second conductivity type layers, and a second electrode. The insulating layer is provided on the first electrode and has an opening where a portion of the first electrode is provided. The first conductivity type layer is provided between the insulating layer and the emission layer and has bandgap energy larger than that of the emission layer. The second conductivity type layer is provided on the emission layer and has a current diffusion layer and a second contact layer. The second contact layer is not superimposed on the opening of the insulating layer, and a thickness of the current diffusion layer is larger than that of the first contact layer. The second electrode has a pad portion and a thin portion extends from the pad portion onto the second contact layer.Type: GrantFiled: November 18, 2013Date of Patent: October 18, 2016Assignee: Kabushiki Kaisha ToshibaInventors: Koichi Genei, Tokuhiko Matsunaga, Katsufumi Kondo, Shinji Nunotani
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Publication number: 20140248729Abstract: According to one embodiment, a semiconductor device includes a substrate and a stacked body on the substrate via a joining metal layer. The stacked body includes a device portion and a peripheral portion. The device portion includes from a bottommost layer to a topmost layer included in the stacked body. The peripheral portion surrounding and provided around the device portion; the peripheral portion is a portion of the bottommost layer to the topmost layer included in the stacked body and includes a portion of a semiconductor layer in contact with the joining metal layer.Type: ApplicationFiled: May 15, 2014Publication date: September 4, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Akihiro Fujiwara, Takashi Hakuno, Tokuhiko Matsunaga, Kimitaka Yoshimura, Katsufumi Kondo
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Patent number: 8816378Abstract: According to one embodiment, a light emitting element, includes: a semiconductor stacked body including a light emitting layer; a first upper electrode being connected directly to the semiconductor stacked body; at least one second upper electrode extending from the first upper electrode, the at least one second upper electrode being connected to the semiconductor stacked body via a first contact layer; a lower electrode; a transparent conductive layer; an intermediate film containing oxygen provided between the semiconductor stacked body and the transparent conductive layer; a light reflecting layer; and a current-blocking layer, at least one slit being provided selectively in the current-blocking layer as viewed from a direction perpendicular to a major surface of the light emitting layer.Type: GrantFiled: June 27, 2013Date of Patent: August 26, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Shinji Nunotani, Yasuhiko Akaike, Kayo Inoue, Katsufumi Kondo, Tokuhiko Matsunaga
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Patent number: 8759852Abstract: According to one embodiment, a semiconductor device includes a substrate and a stacked body on the substrate via a joining metal layer. The stacked body includes a device portion and a peripheral portion. The device portion includes from a bottommost layer to a topmost layer included in the stacked body. The peripheral portion surrounding and provided around the device portion; the peripheral portion is a portion of the bottommost layer to the topmost layer included in the stacked body and includes a portion of a semiconductor layer in contact with the joining metal layer.Type: GrantFiled: March 3, 2011Date of Patent: June 24, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Akihiro Fujiwara, Takashi Hakuno, Tokuhiko Matsunaga, Kimitaka Yoshimura, Katsufumi Kondo
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Publication number: 20140077221Abstract: An embodiment has an emission layer, a first electrode having a reflective metal layer, an insulating layer, first and second conductivity type layers, and a second electrode. The insulating layer is provided on the first electrode and has an opening where a portion of the first electrode is provided. The first conductivity type layer is provided between the insulating layer and the emission layer and has bandgap energy larger than that of the emission layer. The second conductivity type layer is provided on the emission layer and has a current diffusion layer and a second contact layer. The second contact layer is not superimposed on the opening of the insulating layer, and a thickness of the current diffusion layer is larger than that of the first contact layer. The second electrode has a pad portion and a thin portion extends from the pad portion onto the second contact layer.Type: ApplicationFiled: November 18, 2013Publication date: March 20, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Koichi GENEI, Tokuhiko MATSUNAGA, Katsufumi KONDO, Shinji NUNOTANI
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Publication number: 20130292729Abstract: According to one embodiment, a light emitting element, includes: a semiconductor stacked body including a light emitting layer; a first upper electrode being connected directly to the semiconductor stacked body; at least one second upper electrode extending from the first upper electrode, the at least one second upper electrode being connected to the semiconductor stacked body via a first contact layer; a lower electrode; a transparent conductive layer; an intermediate film containing oxygen provided between the semiconductor stacked body and the transparent conductive layer; a light reflecting layer; and a current-blocking layer, at least one slit being provided selectively in the current-blocking layer as viewed from a direction perpendicular to a major surface of the light emitting layer.Type: ApplicationFiled: June 27, 2013Publication date: November 7, 2013Inventors: Shinji NUNOTANI, Yasuhiko AKAIKE, Kayo INOUE, Katsufumi KONDO, Tokuhiko MATSUNAGA
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Publication number: 20130221378Abstract: An LED manufacturing method includes the steps of forming a first insulator film on a semiconductor layer, forming a laminated body including a mask layer and an electrode on the first insulator film, forming a second insulator film to cover the laminated body and a first region of the first insulator film where a laminated body is not formed, anisotropic etching the second insulator film to expose the top surface of the mask layer and a second region of the first insulator film, exposing the surface of a semiconductor layer by removing the first insulator film while keeping the first insulator film between the laminated body and the semiconductor layer, removing the mask layer, and forming a clear conducting layer on top of the exposed surface of the semiconductor layer and the electrode.Type: ApplicationFiled: September 6, 2012Publication date: August 29, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tokuhiko MATSUNAGA, Katsufumi Kondo
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Patent number: 8395172Abstract: According to one embodiment, a light emitting device includes a light emitting layer, a first conductivity type layer, a first electrode, a second conductivity type layer, a current blocking layer and a second electrode. The first conductivity type layer is provided on the light emitting layer. The first electrode is provided on the first conductivity type layer. The second conductivity type layer is provided under the light emitting layer. The current blocking layer is provided in contact with a partial region of a surface of the second conductivity type layer, and has an outer edge protruding from an outer edge of the first electrode. The second electrode is in contact with a surface of the current blocking layer on opposite side from the second conductivity type layer and a region of the surface of the second conductivity type layer not in contact with the current blocking layer.Type: GrantFiled: December 6, 2010Date of Patent: March 12, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Akira Tanaka, Katsufumi Kondo, Tokuhiko Matsunaga
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Publication number: 20120018752Abstract: According to one embodiment, a semiconductor device includes a substrate and a stacked body on the substrate via a joining metal layer. The stacked body includes a device portion and a peripheral portion. The device portion includes from a bottommost layer to a topmost layer included in the stacked body. The peripheral portion surrounding and provided around the device portion; the peripheral portion is a portion of the bottommost layer to the topmost layer included in the stacked body and includes a portion of a semiconductor layer in contact with the joining metal layer.Type: ApplicationFiled: March 3, 2011Publication date: January 26, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Akihiro FUJIWARA, Takashi HAKUNO, Tokuhiko MATSUNAGA, Kimitaka YOSHIMURA, Katsufumi KONDO
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Publication number: 20110291133Abstract: According to one embodiment, a light emitting device includes a light emitting layer, a first conductivity type layer, a first electrode, a second conductivity type layer, a current blocking layer and a second electrode. The first conductivity type layer is provided on the light emitting layer. The first electrode is provided on the first conductivity type layer. The second conductivity type layer is provided under the light emitting layer. The current blocking layer is provided in contact with a partial region of a surface of the second conductivity type layer, and has an outer edge protruding from an outer edge of the first electrode. The second electrode is in contact with a surface of the current blocking layer on opposite side from the second conductivity type layer and a region of the surface of the second conductivity type layer not in contact with the current blocking layer.Type: ApplicationFiled: December 6, 2010Publication date: December 1, 2011Applicant: Kabushiki Kaisha ToshibaInventors: Akira TANAKA, Katsufumi Kondo, Tokuhiko Matsunaga
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Patent number: 6417020Abstract: An electrode of a metal, which is one of Group IV and VI elements, is deposited on an n-type InxAlyGa1−x−yN layer. Alternatively, after an electrode material of carbon, germanium), selenium, rhodium, tellurium, iridium, zirconium, hafnium, copper, titanium nitride, tungsten nitride, molybdenum or titanium silicide, is deposited on an n-type InxAlyGa1−x−yN layer or a p-type InxAlyGa1−x−yN layer, an impurity for increasing the carrier concentration of the semiconductor layer is ion-implanted, and the annealing is carried out. Thus, it is possible to provide a light emitting semiconductor device, which has a low contact resistance and a sufficient bond strength to the InxAlyGa1−x−yN layer while maintaining the crystallinity of the InxAlyGa1−x−yN layer.Type: GrantFiled: July 2, 2001Date of Patent: July 9, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Koichi Nitta, Haruhiko Okazaki, Tokuhiko Matsunaga
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Publication number: 20010038103Abstract: An electrode of a metal, which is one of Group IV and VI elements, is deposited on an n-type InxAlyGa1-x-yN layer. Alternatively, after an electrode material of carbon, germanium), selenium, rhodium, tellurium, iridium, zirconium, hafnium, copper, titanium nitride, tungsten nitride, molybdenum or titanium silicide, is deposited on an n-type InxAlyGa1-x-yN layer or a p-type InxAlyGa1-x-yN layer, an impurity for increasing the carrier concentration of the semiconductor layer is ion-implanted, and the annealing is carried out. Thus, it is possible to provide a light emitting semiconductor device, which has a low contact resistance and a sufficient bond strength to the InxAlyGa1-x-yN layer while maintaining the crystallinity of the InxAlyGa1-x-yN layer.Type: ApplicationFiled: July 2, 2001Publication date: November 8, 2001Applicant: Kabushiki Kaisha ToshibaInventors: Koichi Nitta, Haruhiko Okazaki, Tokuhiko Matsunaga
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Patent number: 6281526Abstract: An electrode of a metal, which is one of Group IV and VI elements, is deposited on an n-type InxAlyGa1−x−yN layer. Alternatively, after an electrode material of carbon, germanium), selenium, rhodium, tellurium, iridium, zirconium, hafnium, copper, titanium nitride, tungsten nitride, molybdenum or titanium silicide, is deposited on an n-type InxAlyGa1−x−yN layer or a p-type InxAlyGa1−x−yN layer, an impurity for increasing the carrier concentration of the semiconductor layer is ion-implanted, and the annealing is carried out. Thus, it is possible to provide a light emitting semiconductor device, which has a low contact resistance and a sufficient bond strength to the InxAlyGa1−x−yN layer while maintaining the crystallinity of the InxAlyGa1−x−yN layer.Type: GrantFiled: March 4, 1998Date of Patent: August 28, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Koichi Nitta, Haruhiko Okazaki, Tokuhiko Matsunaga