Patents by Inventor Osamu Imafuji
Osamu Imafuji 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: 20230019414Abstract: A crystal that is useful for semiconductor element and a semiconductor element that has enhanced electrical properties are provided. A crystal, including: a corundum structured crystalline oxide, the crystalline oxide including gallium and/or indium, and the crystalline oxide further including a metal of Group 4 of the periodic table. The crystal is used to make a semiconductor element, and the obtained semiconductor element is used to make a semiconductor device such as a power card. Also, the semiconductor element and the semiconductor device are used to make a semiconductor system.Type: ApplicationFiled: September 23, 2022Publication date: January 19, 2023Inventors: Ryohei KANNO, Osamu IMAFUJI, Kazuyoshi NORIMATSU, Yuji KATO
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Publication number: 20220384663Abstract: Provided is a semiconductor element including: a multilayer structure including: a conductive substrate; and an oxide semiconductor film arranged directly on the conductive substrate or over the conductive substrate via a different layer, the oxide semiconductor film including an oxide, as a major component, having a corundum structure, the conductive substrate having a larger area than the oxide semiconductor film.Type: ApplicationFiled: August 5, 2022Publication date: December 1, 2022Applicant: FLOSFIA INC.Inventors: Yusuke MATSUBARA, Osamu IMAFUJI, Hiroyuki ANDO, Hideki TAKEHARA, Takashi SHINOHE, Mitsuru OKIGAWA
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Publication number: 20220376056Abstract: Provided is a semiconductor element including: a multilayer structure including: a conductive substrate; and an oxide semiconductor film arranged directly on the conductive substrate or over the conductive substrate via a different layer, the oxide semiconductor film including an oxide, as a major component, containing gallium, the conductive substrate having a larger area than the oxide semiconductor film.Type: ApplicationFiled: August 5, 2022Publication date: November 24, 2022Inventors: Yusuke MATSUBARA, Osamu IMAFUJI, Hiroyuki ANDO, Hideki TAKEHARA, Takashi SHINOHE, Mitsuru OKIGAWA
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Publication number: 20220310798Abstract: An electrically-conductive metal oxide film that is useful for semiconductor element and a semiconductor element that has enhanced electrical properties are provided. An electrically-conductive metal oxide film comprising: a metal oxide as a major component, wherein the metal oxide includes at least a first metal selected from a metal of Group 4 of the periodic table and a second metal selected from a metal of Group 13 of the periodic table. The electrically-conductive metal oxide film is used to make a semiconductor element, and the obtained semiconductor element is used to make a semiconductor device such as a power card. Also, the semiconductor element and the semiconductor device are used to make a semiconductor system.Type: ApplicationFiled: June 14, 2022Publication date: September 29, 2022Inventors: Ryohei KANNO, Osamu IMAFUJI, Kazuyoshi NORIMATSU, Yuji KATO
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Publication number: 20220231174Abstract: Provided is a semiconductor element including at least a multilayer structure including a semiconductor layer, a first metal layer, a second metal layer and a third metal layer, the semiconductor layer including an oxide semiconductor film, the first metal layer, the second metal layer and the third metal layer being arranged on the semiconductor layer, the first metal layer, the second metal layer and the third metal layer respectively including one or two or more different metals, the first metal layer being in ohmic contact with the semiconductor layer, the second metal layer being disposed between the first metal layer and the third metal layer, and the second metal layer containing Pt or/and Pd.Type: ApplicationFiled: April 1, 2022Publication date: July 21, 2022Inventor: Osamu IMAFUJI
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Publication number: 20220223682Abstract: Provided is a semiconductor element including; a semiconductor film; and a porous layer disposed on a first surface side of the semiconductor film or a second surface side opposite from the first surface side, a porosity of the porous layer being no more than 10%.Type: ApplicationFiled: April 1, 2022Publication date: July 14, 2022Inventors: Osamu IMAFUJI, Yusuke MATSUBARA
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Publication number: 20220158000Abstract: Provided is a semiconductor device in which crystal defects due to stress concentration in a semiconductor layer caused by an insulator film are prevented, the semiconductor device that is particularly useful for power devices. A semiconductor device including at least: a semiconductor layer; a Schottky electrode; and an insulator layer provided between a part of the semiconductor layer and the Schottky electrode, wherein the semiconductor layer contains a crystalline oxide semiconductor, and wherein the insulator layer has a taper angle of 10° or less.Type: ApplicationFiled: January 14, 2022Publication date: May 19, 2022Inventors: Mitsuru OKIGAWA, Yasushi HIGUCHI, Yusuke MATSUBARA, Osamu IMAFUJI, Takashi SHINOHE
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Publication number: 20220140145Abstract: Provided are a multilayer structure in which crystal defects due to stress concentration in a semiconductor layer caused by an insulator film are prevented and a semiconductor device using the multilayer structure, the multilayer structure and the semiconductor device that are particularly useful for power devices. A multilayer structure in which an insulator film is arranged on a part of a semiconductor film, wherein the semiconductor film has a corundum structure and contains a crystalline oxide semiconductor containing one or two or more metals selected from groups 9 and 13 of the periodic table, and wherein the insulator film has a taper angle of 20° or less.Type: ApplicationFiled: January 14, 2022Publication date: May 5, 2022Inventors: Mitsuru OKIGAWA, Yasushi HIGUCHI, Yusuke MATSUBARA, Osamu IMAFUJI, Takashi SHINOHE
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Publication number: 20210217854Abstract: The semiconductor element and the semiconductor device according to the disclosure is excellent in electrical characteristics are provided. A semiconductor element, including: an electrode, and the electrode having a corundum structure. The semiconductor element is used to make a semiconductor device such as a power card. Also, the semiconductor element and the semiconductor device are used to make a semiconductor system.Type: ApplicationFiled: January 11, 2021Publication date: July 15, 2021Inventors: Ryohei KANNO, Osamu IMAFUJI, Kazuyoshi NORIMATSU, Yuji KATO
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Publication number: 20210217869Abstract: A crystal that is useful for semiconductor element and a semiconductor element that has enhanced electrical properties are provided. A crystal, including: a corundum structured crystalline oxide, the crystalline oxide including gallium and/or indium, and the crystalline oxide further including a metal of Group 4 of the periodic table. The crystal is used to make a semiconductor element, and the obtained semiconductor element is used to make a semiconductor device such as a power card. Also, the semiconductor element and the semiconductor device are used to make a semiconductor system.Type: ApplicationFiled: January 11, 2021Publication date: July 15, 2021Inventors: Ryohei KANNO, Osamu IMAFUJI, Kazuyoshi NORIMATSU, Yuji KATO
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Patent number: 10892597Abstract: A nitride semiconductor laser includes: a first nitride semiconductor layer; a light-emitting layer formed on the first nitride semiconductor layer and including a nitride semiconductor; a second nitride semiconductor layer formed on the light-emitting layer and having a ridge portion; an electrode component formed on the second nitride semiconductor layer, and which is wider than the ridge portion; and a dielectric layer formed on side surfaces of the ridge portion and including SiO2. A space is present between the electrode component and the dielectric layer, and the electrode component is prevented from being in contact with the dielectric layer by the space, and is in contact with the upper surface of the ridge portion.Type: GrantFiled: June 28, 2017Date of Patent: January 12, 2021Assignee: PANASONIC CORPORATIONInventors: Hiroyuki Hagino, Osamu Imafuji, Shinichiro Nozaki
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Publication number: 20190245322Abstract: A nitride semiconductor laser includes: a first nitride semiconductor layer; a light-emitting layer formed on the first nitride semiconductor layer and including a nitride semiconductor; a second nitride semiconductor layer formed on the light-emitting layer and having a ridge portion; an electrode component formed on the second nitride semiconductor layer, and which is wider than the ridge portion; and a dielectric layer formed on side surfaces of the ridge portion and including SiO2. A space is present between the electrode component and the dielectric layer, and the electrode component is prevented from being in contact with the dielectric layer by the space, and is in contact with the upper surface of the ridge portion.Type: ApplicationFiled: June 28, 2017Publication date: August 8, 2019Inventors: Hiroyuki HAGINO, Osamu IMAFUJI, Shinichiro NOZAKI
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Patent number: 10141720Abstract: A nitride semiconductor laser element includes an electron barrier layer between a p-side light guide layer and a p-type clad layer. The electron barrier layer has a bandgap energy larger than that of the p-type clad layer. The p-side light guide layer is made of AlxGa1?xN containing no Indium, where 0?x<1. A film thickness dn of the n-side light guide layer and a film thickness dp of the p-side light guide layer satisfy relationships dp?0.25 ?m and dn?dp.Type: GrantFiled: January 9, 2018Date of Patent: November 27, 2018Assignee: PANASONIC CORPORATIONInventors: Masao Kawaguchi, Osamu Imafuji, Shinichiro Nozaki, Hiroyuki Hagino
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Publication number: 20180131161Abstract: A nitride semiconductor laser element includes an electron barrier layer between a p-side light guide layer and a p-type clad layer. The electron barrier layer has a bandgap energy larger than that of the p-type clad layer. The p-side light guide layer is made of AlxGa1?xN containing no Indium, where 0 ?x<1. A film thickness dn of the n-side light guide layer and a film thickness dp of the p-side light guide layer satisfy relationships dp?0.25 ?m and dn?dp.Type: ApplicationFiled: January 9, 2018Publication date: May 10, 2018Inventors: MASAO KAWAGUCHI, Osamu Imafuji, Shinichiro Nozaki, Hiroyuki Hagino
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Patent number: 7301979Abstract: A semiconductor laser device of the present invention includes: a first conductivity type cladding layer; an active layer; and a second conductivity type cladding layer, which are on a substrate. The semiconductor laser device further includes a stripe structure for injecting carriers therein. A width of the stripe is wider at a front end face of a resonator from which laser light is emitted than at a rear end face that is located on an opposite side of the front end face, and a reflectance of the front end face is lower than a reflectance of the rear end face. With this configuration, the injection of carriers into an active layer can be controlled in accordance with an optical intensity distribution along the resonator direction within the semiconductor laser, thus achieving a decrease in threshold current, an enhancement of a slope efficiency and an enhancement of a kink level.Type: GrantFiled: April 14, 2004Date of Patent: November 27, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Keiji Ito, Isao Kidoguchi, Toru Takayama, Osamu Imafuji
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Patent number: 6909733Abstract: A semiconductor laser device comprises, on top of an active layer, an n-type cladding layer of Alx1Ga1?x1As and a p-type cladding layer of (AlxGa1?x)yIn1?yP for defining a barrier height. The p-type cladding layer for defining a barrier height contains more component elements than the n-type cladding layer. The potential difference between the conduction band edges of the p-type cladding layer for defining a barrier height and the active layer is greater than the potential difference between the conduction band edges of the n-type cladding layer and the active layer. The carriers in the active layer are prevented from overflowing into the p-type cladding layer and a material having a high thermal conductivity is used for the n-type cladding layer to prevent the phenomenon of thermal saturation, thereby providing improved optical output.Type: GrantFiled: October 3, 2001Date of Patent: June 21, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Katsuya Samonji, Toru Takayama, Osamu Imafuji, Masaaki Yuri
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Patent number: 6888870Abstract: A semiconductor laser has a first conduction-type cladding layer, an active layer, and a second conduction-type cladding layer formed on a first conduction-type semiconductor substrate. The second conduction-type cladding layer has a mesa-type stripe-shaped recessed portion in at least four spots, so as to form a central ridge portion, which constitutes a ridge-type current confinement portion, and two or more lateral ridge portions, which are positioned on both sides of the central ridge portion, have a height larger than to that of the central ridge portion, and include the second conduction-type cladding layer. An insulation film with a lower refractive index than the second conduction-type cladding layer is formed in a pair of stripes disposed respectively in the regions from the side surface of the second conduction-type cladding layer on both side surfaces of the central ridge portion toward the outside. The insulation film is not formed on the central ridge portion.Type: GrantFiled: July 31, 2002Date of Patent: May 3, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Koji Makita, Hideto Adachi, Toshiya Kawata, Hiroshi Asaka, Osamu Imafuji, Toshiya Fukuhisa, Akira Takamori
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Publication number: 20050035359Abstract: A substrate includes: a crystalline substrate including a primary surface and a crystal plane provided within the primary surface so as to have a surface orientation different from a surface orientation of the primary surface; a semiconductor layered structure grown over the crystalline substrate; and an active region provided at a portion in the semiconductor layer structure above the crystal plane.Type: ApplicationFiled: September 30, 2004Publication date: February 17, 2005Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Masahiro ISHIDA, Shinji NAKAMURA, Kenji ORITA, Osamu IMAFUJI, Masaaki YURI
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Publication number: 20040233957Abstract: A semiconductor laser device of the present invention includes: a first conductivity type cladding layer; an active layer; and a second conductivity type cladding layer, which are on a substrate. The semiconductor laser device further includes a stripe structure for injecting carriers therein. A width of the stripe is wider at a front end face of a resonator from which laser light is emitted than at a rear end face that is located on an opposite side of the front end face, and a reflectance of the front end face is lower than a reflectance of the rear end face. With this configuration, the injection of carriers into an active layer can be controlled in accordance with an optical intensity distribution along the resonator direction within the semiconductor laser, thus achieving a decrease in threshold current, an enhancement of a slope efficiency and an enhancement of a kink level.Type: ApplicationFiled: April 14, 2004Publication date: November 25, 2004Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Keiji Ito, Isao Kidoguchi, Toru Takayama, Osamu Imafuji
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Patent number: 6821805Abstract: Disclosed is a semiconductor device which comprises a substrate in which surface is formed a depression having a closed figure when viewed from the substrate normal and a semiconductor layer which is formed on the surface of the substrate by crystal growth from at least an inside face of the depression.Type: GrantFiled: October 5, 2000Date of Patent: November 23, 2004Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Shinji Nakamura, Masahiro Ishida, Kenji Orita, Osamu Imafuji, Masaaki Yuri