Patents by Inventor Yohei YUDA
Yohei YUDA 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: 20240352619Abstract: An object is to provide a technique capable of increasing device characteristics. A crystal lamination structure includes a Ga2O3 single-crystal substrate having a first main surface. The crystal lamination structure includes a Ga2O3 single-crystal layer as an epitaxial growth layer provided on the first main surface of the Ga2O3 single-crystal substrate and having a second main surface on a side opposite to the Ga2O3 single-crystal substrate. A plane direction of the first main surface of the Ga2O3 single-crystal substrate is plane. A plane direction of the second main surface of the Ga2O3 single-crystal layer is plane.Type: ApplicationFiled: September 3, 2021Publication date: October 24, 2024Applicant: Mitsubishi Electric CorporationInventors: Yohei YUDA, Tatsuro WATAHIKI, Yoshinao KUMAGAI, Ken GOTO
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Patent number: 11728393Abstract: An object is to provide a technology that can enhance electrical characteristics of a semiconductor device. A semiconductor device is a semiconductor device provided with a semiconductor element. The semiconductor device includes: an n-type single-crystal gallium oxide layer including a first main surface; an electrode disposed on the first main surface of the n-type single-crystal gallium oxide layer or above the first main surface, the electrode being an electrode of the semiconductor element; a p-type oxide semiconductor layer disposed between the n-type single-crystal gallium oxide layer and the electrode; and an amorphous gallium oxide layer disposed between the n-type single-crystal gallium oxide layer and the p-type oxide semiconductor layer.Type: GrantFiled: March 13, 2019Date of Patent: August 15, 2023Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Yohei Yuda, Tatsuro Watahiki
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Patent number: 11251282Abstract: In order to provide a power semiconductor device reducing a leakage current due to a defect layer and having a small fluctuation in a threshold voltage, included are an n-type epitaxial film layer formed on a surface of the single crystal n-type semiconductor substrate and having a concave portion and a convex portion; an insulating film formed on a first region in a top portion of the convex portion; a p-type thin film layer formed on a surface of the insulating film and a surface of the n-type epitaxial film layer to form a pn junction between the p-type thin film layer and the n-type epitaxial film layer; and an anode electrode, at least part of which is formed on a surface of the p-type thin film layer and part of which passes through the p-type thin film layer and the insulating film.Type: GrantFiled: December 18, 2018Date of Patent: February 15, 2022Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Tatsuro Watahiki, Yohei Yuda
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Patent number: 11239323Abstract: An object is to provide a technology for enabling prevention of deterioration of characteristics of an oxide semiconductor device. The oxide semiconductor device includes an n-type gallium oxide epitaxial layer, a p-type oxide semiconductor layer, and an oxide layer. The p-type oxide semiconductor layer is disposed above the n-type gallium oxide epitaxial layer, contains an element different from gallium as a main component, and has p-type conductivity. The oxide layer is disposed between the n-type gallium oxide epitaxial layer and the p-type oxide semiconductor layer, and is made of a material different from gallium oxide and different at least partly from a material of the p-type oxide semiconductor layer.Type: GrantFiled: August 8, 2019Date of Patent: February 1, 2022Assignees: MITSUBISHI ELECTRIC CORPORATION, TOKYO INSTITUTE OF TECHNOLOGYInventors: Yohei Yuda, Tatsuro Watahiki, Shinsuke Miyajima, Yuki Takiguchi
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Patent number: 11222985Abstract: An n-type semiconductor layer has a single-crystal structure and is made of a wide-gap semiconducting material. A p-type semiconductor layer is provided on the n-type semiconductor layer and made of a material different from the aforementioned wide-gap semiconducting material, and has either a microcrystalline structure or an amorphous structure. An electrode is provided on at least one of the n-type semiconductor layer and the p-type semiconductor layer.Type: GrantFiled: February 14, 2017Date of Patent: January 11, 2022Assignees: Mitsubishi Electric Corporation, Tokyo Institute of TechnologyInventors: Tatsuro Watahiki, Yohei Yuda, Akihiko Furukawa, Shinsuke Miyajima, Yuki Takiguchi
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Publication number: 20210391428Abstract: An object is to provide a technology that can enhance electrical characteristics of a semiconductor device. A semiconductor device is a semiconductor device provided with a semiconductor element. The semiconductor device includes: an n-type single-crystal gallium oxide layer including a first main surface; an electrode disposed on the first main surface of the n-type single-crystal gallium oxide layer or above the first main surface, the electrode being an electrode of the semiconductor element; a p-type oxide semiconductor layer disposed between the n-type single-crystal gallium oxide layer and the electrode; and an amorphous gallium oxide layer disposed between the n-type single-crystal gallium oxide layer and the p-type oxide semiconductor layer.Type: ApplicationFiled: March 13, 2019Publication date: December 16, 2021Applicant: Mitsubishi Electric CorporationInventors: Yohei YUDA, Tatsuro WATAHIKI
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Publication number: 20210234009Abstract: An object is to provide a technology for enabling prevention of deterioration of characteristics of an oxide semiconductor device. The oxide semiconductor device includes an n-type gallium oxide epitaxial layer, a p-type oxide semiconductor layer, and an oxide layer. The p-type oxide semiconductor layer is disposed above the n-type gallium oxide epitaxial layer, contains an element different from gallium as a main component, and has p-type conductivity. The oxide layer is disposed between the n-type gallium oxide epitaxial layer and the p-type oxide semiconductor layer, and is made of a material different from gallium oxide and different at least partly from a material of the p-type oxide semiconductor layer.Type: ApplicationFiled: August 8, 2019Publication date: July 29, 2021Applicants: Mitsubishi Electric Corporation, Tokyo Institute of TechnologyInventors: Yohei YUDA, Tatsuro WATAHIKI, Shinsuke MIYAJIMA, Yuki TAKIGUCHI
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Patent number: 10971634Abstract: An oxide semiconductor device has an improved withstand voltage when an inverse voltage is applied, while suppressing diffusion of different types of materials to a Schottky interface. The oxide semiconductor device includes an n-type gallium oxide epitaxial layer, p-type oxide semiconductor layers of an oxide that is a different material from the material for the gallium oxide epitaxial layer, a dielectric layer formed to cover at least part of a side surface of the oxide semiconductor layer, an anode electrode, and a cathode electrode. Hetero pn junctions are formed between the lower surfaces of the oxide semiconductor layers and a gallium oxide substrate or between the lower surfaces of the oxide semiconductor layers and the gallium oxide epitaxial layer.Type: GrantFiled: June 8, 2018Date of Patent: April 6, 2021Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Yohei Yuda, Tatsuro Watahiki, Akihiko Furukawa
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Publication number: 20210074826Abstract: In order to provide a power semiconductor device reducing a leakage current due to a defect layer and having a small fluctuation in a threshold voltage, included are an n-type epitaxial film layer formed on a surface of the single crystal n-type semiconductor substrate and having a concave portion and a convex portion; an insulating film formed on a first region in a top portion of the convex portion; a p-type thin film layer formed on a surface of the insulating film and a surface of the n-type epitaxial film layer to form a pn junction between the p-type thin film layer and the n-type epitaxial film layer; and an anode electrode, at least part of which is formed on a surface of the p-type thin film layer and part of which passes through the p-type thin film layer and the insulating film.Type: ApplicationFiled: December 18, 2018Publication date: March 11, 2021Applicant: Mitsubishi Electric CorporationInventors: Tatsuro WATAHIKI, Yohei YUDA
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Publication number: 20200295203Abstract: An n-type semiconductor layer has a single-crystal structure and is made of a wide-gap semiconducting material. A p-type semiconductor layer is provided on the n-type semiconductor layer and made of a material different from the aforementioned wide-gap semiconducting material, and has either a microcrystalline structure or an amorphous structure. An electrode is provided on at least one of the n-type semiconductor layer and the p-type semiconductor layer.Type: ApplicationFiled: February 14, 2017Publication date: September 17, 2020Applicants: Mitsubishi Electric Corporation, Tokyo Institute of TechnologyInventors: Tatsuro WATAHIKI, Yohei YUDA, Akihiko FURUKAWA, Shinsuke MIYAJIMA, Yuki TAKIGUCHI
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Publication number: 20200185541Abstract: An oxide semiconductor device has an improved withstand voltage when an inverse voltage is applied, while suppressing diffusion of different types of materials to a Schottky interface. The oxide semiconductor device includes an n-type gallium oxide epitaxial layer, p-type oxide semiconductor layers of an oxide that is a different material from the material for the gallium oxide epitaxial layer, a dielectric layer formed to cover at least part of a side surface of the oxide semiconductor layer, an anode electrode, and a cathode electrode. Hetero pn junctions are formed between the lower surfaces of the oxide semiconductor layers and a gallium oxide substrate or between the lower surfaces of the oxide semiconductor layers and the gallium oxide epitaxial layer.Type: ApplicationFiled: June 8, 2018Publication date: June 11, 2020Applicant: Mitsubishi Electric CorporationInventors: Yohei YUDA, Tatsuro WATAHIKI, Akihiko FURUKAWA
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Patent number: 10483110Abstract: A p-type oxide semiconductor is prevented from being oxidized by oxygen in an n-type oxide semiconductor even if the p-type oxide semiconductor is provided as a termination structure in the n-type oxide semiconductor. A semiconductor device includes an n-type gallium oxide substrate, an anode electrode joined to the n-type gallium oxide substrate, and a cathode electrode provided on the n-type gallium oxide substrate. Current flows between the anode electrode and the cathode electrode via the n-type gallium oxide substrate provided between the anode electrode and the cathode electrode. The semiconductor device further includes a p-type oxide semiconductor layer provided adjacent to a junction between the anode electrode and the n-type gallium oxide substrate, and a nitride layer provided between the p-type oxide semiconductor layer and the n-type gallium oxide substrate.Type: GrantFiled: June 8, 2017Date of Patent: November 19, 2019Assignee: Mitsubishi Electric CorporationInventors: Yohei Yuda, Tatsuro Watahiki
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Publication number: 20190267237Abstract: A p-type oxide semiconductor is prevented from being oxidized by oxygen in an n-type oxide semiconductor even if the p-type oxide semiconductor is provided as a termination structure in the n-type oxide semiconductor. A semiconductor device includes an n-type gallium oxide substrate, an anode electrode joined to the n-type gallium oxide substrate, and a cathode electrode provided on the n-type gallium oxide substrate. Current flows between the anode electrode and the cathode electrode via the n-type gallium oxide substrate provided between the anode electrode and the cathode electrode. The semiconductor device further includes a p-type oxide semiconductor layer provided adjacent to a junction between the anode electrode and the n-type gallium oxide substrate, and a nitride layer provided between the p-type oxide semiconductor layer and the n-type gallium oxide substrate.Type: ApplicationFiled: June 8, 2017Publication date: August 29, 2019Applicant: Mitsubishi Electric CorporationInventors: Yohei YUDA, Tatsuro WATAHIKI
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Publication number: 20150270419Abstract: A photoelectric conversion element includes: a photoelectric conversion layer; and first and second electrodes formed on surfaces of the photoelectric conversion layer, wherein at least one of the first and second electrodes includes a translucent conductive base layer made of a translucent conductive material, and a translucent conductive mesh layer selectively buried in the translucent conductive base layer, having electrical resistivity lower than electrical resistivity of the translucent conductive base layer, and formed in a translucent conductive film pattern.Type: ApplicationFiled: March 13, 2015Publication date: September 24, 2015Applicant: Mitsubishi Electric CorporationInventors: Yohei YUDA, Takayuki MORIOKA, Tsutomu MATSUURA, Tatsuro WATAHIKI