Patents by Inventor Daiki Wakimoto
Daiki Wakimoto 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: 11923464Abstract: A Schottky barrier diode includes a semiconductor layer including a Ga2O3-based single crystal, an anode electrode that forms a Schottky junction with the semiconductor layer and is configured so that a portion in contact with the semiconductor layer includes Mo or W, and a cathode electrode. A turn-on voltage thereof is not less than 0.3 V and not more than 0.5 V.Type: GrantFiled: June 12, 2018Date of Patent: March 5, 2024Assignees: Tamura Corporation, Novel Crystal Technology, Inc.Inventors: Kohei Sasaki, Daiki Wakimoto, Yuki Koishikawa, Quang Tu Thieu
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Publication number: 20230395731Abstract: A Schottky barrier diode includes an n-type semiconductor layer including a gallium oxide-based semiconductor, an insulating film including SiO2 and covering a portion of an upper surface of the n-type semiconductor layer, and an anode electrode which is connected to the upper surface of the n-type semiconductor layer to form a Schottky junction with the n-type semiconductor layer and at least a portion of an edge of which is located on the insulating film. The insulating film further includes a first layer in contact with the n-type semiconductor layer and a second layer on the first layer. A refractive index of the first layer is lower than a refractive index of the second layer. The n-type semiconductor layer further includes a guard ring surrounding a junction with the anode electrode.Type: ApplicationFiled: June 1, 2023Publication date: December 7, 2023Applicants: TAMURA CORPORATION, Novel Crystal Technology, Inc.Inventors: Shinya YAMAGUCHI, Yuki UCHIDA, Daiki WAKIMOTO, Akio TAKATSUKA
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Patent number: 11563092Abstract: A Ga2O3-based semiconductor device includes a Ga2O3-based crystal layer including a donor, and an N-doped region formed in at least a part of the Ga2O3-based crystal layer.Type: GrantFiled: April 26, 2018Date of Patent: January 24, 2023Assignees: National Institute of Information and Communications Technology, Tamura Corporation, Novel Crystal Technology, IncInventors: Masataka Higashiwaki, Yoshiaki Nakata, Takafumi Kamimura, Man Hoi Wong, Kohei Sasaki, Daiki Wakimoto
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Patent number: 11043602Abstract: Provided is a Schottky barrier diode which is configured from a Ga2O3-based semiconductor, and has a lower rising voltage than a conventional one. In one embodiment, the Schottky barrier diode 1 is provided which has: a semiconductor layer 10 configured from a Ga2O3-based single crystal; an anode electrode 11 which forms a Schottky junction with the semiconductor layer 10, and has a portion which contacts the semiconductor layer 10 and is composed of Fe or Cu; and a cathode electrode 12.Type: GrantFiled: February 19, 2018Date of Patent: June 22, 2021Assignees: Tamura Corporation, Novel Crystal Technology, Inc.Inventors: Kohei Sasaki, Daiki Wakimoto, Yuki Koishikawa, Quang Tu Thieu
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Publication number: 20210151611Abstract: A Schottky barrier diode includes a semiconductor layer including a Ga2O3-based single crystal, an anode electrode that forms a Schottky junction with the semiconductor layer and is configured so that a portion in contact with the semiconductor layer includes Mo or W, and a cathode electrode. A turn-on voltage thereof is not less than 0.3 V and not more than 0.5 V.Type: ApplicationFiled: June 12, 2018Publication date: May 20, 2021Applicants: TAMURA CORPORATION, Novel Crystal Technology, Inc.Inventors: Kohei SASAKI, Daiki WAKIMOTO, Yuki KOISHIKAWA, Quang Tu THIEU
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Patent number: 11011653Abstract: Provided is a Schottky barrier diode which is configured from a Ga2O3-based semiconductor, and has a lower rising voltage than a conventional one. In one embodiment, the Schottky barrier diode 1 is provided which has: a semiconductor layer 10 configured from a Ga2O3-based single crystal; an anode electrode 11 which forms a Schottky junction with the semiconductor layer 10, and has a portion which contacts the semiconductor layer 10 and is composed of Fe or Cu; and a cathode electrode 12.Type: GrantFiled: February 19, 2018Date of Patent: May 18, 2021Assignees: Tamura Corporation, Novel Crystal Technology, Inc.Inventors: Kohei Sasaki, Daiki Wakimoto, Yuki Koishikawa, Quang Tu Thieu
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Publication number: 20200144377Abstract: A Ga2O3-based semiconductor device includes a Ga2O3-based crystal layer including a donor, and an N-doped region formed in at least a part of the Ga2O3-based crystal layer.Type: ApplicationFiled: April 26, 2018Publication date: May 7, 2020Applicants: NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY, TAMURA CORPORATION, NOVEL CRYSTAL TECHNOLOGY, INC.Inventors: Masataka HIGASHIWAKI, Yoshiaki NAKATA, Takafumi KAMIMURA, Man Hoi WONG, Kohei SASAKI, Daiki WAKIMOTO
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Publication number: 20190363197Abstract: Provided is a Schottky barrier diode which is configured from a Ga2O3-based semiconductor, and has a lower rising voltage than a conventional one. In one embodiment, the Schottky barrier diode 1 is provided which has: a semiconductor layer 10 configured from a Ga2O3-based single crystal; an anode electrode 11 which forms a Schottky junction with the semiconductor layer 10, and has a portion which contacts the semiconductor layer 10 and is composed of Fe or Cu; and a cathode electrode 12.Type: ApplicationFiled: February 19, 2018Publication date: November 28, 2019Applicants: TAMURA CORPORATION, NOVEL CRYSTAL TECHNOLOGY, INC.Inventors: Kohei SASAKI, Daiki WAKIMOTO, Yuki KOISHIKAWA, Quang Tu THIEU
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Patent number: 10358742Abstract: A method of growing a conductive Ga2O3-based crystal film by MBE includes producing a Ga vapor and a Si-containing vapor and supplying the vapors as molecular beams onto a surface of a Ga2O3-based crystal substrate so as to grow the Ga2O3-based crystal film. The Ga2O3-based crystal film includes a Si-containing Ga2O3-based single crystal film. The Si-containing vapor is produced by heating Si or a Si compound and Ga while allowing the Si or a Si compound to contact with the Ga.Type: GrantFiled: June 2, 2017Date of Patent: July 23, 2019Assignees: TAMURA CORPORATION, Novel Crystal Technology, Inc.Inventors: Kohei Sasaki, Daiki Wakimoto
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Patent number: 9926646Abstract: A method for growing a ?-Ga2O3-based single crystal, can provide a plate-shaped ?-Ga2O3-based single crystal having high crystal quality. In one embodiment, a method for growing a ?-Ga2O3-based single crystal employing an EFG method is provided, the method including: bringing a plate-shaped seed crystal into contact with a Ga2O3-based melt, wherein the plate-shaped seed crystal includes a ?-Ga2O3-based single crystal having a defect density of not more than 5×105 /cm2 in the whole region; and pulling up the seed crystal to grow a ?-Ga2O3-based single crystal.Type: GrantFiled: October 9, 2013Date of Patent: March 27, 2018Assignees: TAMURA CORPORATION, KOHA CO., LTD.Inventors: Shinya Watanabe, Daiki Wakimoto, Kazuyuki Iizuka, Kimiyoshi Koshi, Takekazu Masui
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Patent number: 9903045Abstract: A method for growing a ?-Ga2O3-based single crystal, can provide a plate-shaped ?-Ga2O3-based single crystal having high crystal quality. In one embodiment, a method for growing a ?-Ga2O3-based single crystal employing an EFG method is provided, the method including: bringing a plate-shaped seed crystal into contact with a Ga2O3-based melt, wherein the plate-shaped seed crystal includes a ?-Ga2O3-based single crystal having a defect density of not more than 5×105 /cm2 in the whole region; and pulling up the seed crystal to grow a ?-Ga2O3-based single crystal.Type: GrantFiled: October 9, 2013Date of Patent: February 27, 2018Assignees: TAMURA CORPORATION, KOHA CO., LTD.Inventors: Shinya Watanabe, Daiki Wakimoto, Kazuyuki Iizuka, Kimiyoshi Koshi, Takekazu Masui
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Publication number: 20170350037Abstract: A method of growing a conductive Ga2O3-based crystal film by MBE includes producing a Ga vapor and a Si-containing vapor and supplying the vapors as molecular beams onto a surface of a Ga2O3-based crystal substrate so as to grow the Ga2O3-based crystal film. The Ga2O3-based crystal film includes a Si-containing Ga2O3-based single crystal film. The Si-containing vapor is produced by heating Si or a Si compound and Ga while allowing the Si or a Si compound to contact with the Ga.Type: ApplicationFiled: June 2, 2017Publication date: December 7, 2017Applicants: TAMURA CORPORATION, Novel Crystal Techonology, Inc.Inventors: Kohei SASAKI, Daiki WAKIMOTO
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Patent number: 9349915Abstract: A ?-Ga2O3-based single crystal substrate includes a ?-Ga2O3-based single crystal. The ?-Ga2O3-based single crystal includes a full width at half maximum of an x-ray rocking curve of less than 75 seconds.Type: GrantFiled: February 26, 2015Date of Patent: May 24, 2016Assignees: TAMURA CORPORATION, KOHA CO., LTD.Inventors: Kimiyoshi Koshi, Shinya Watanabe, Masaru Takizawa, Yu Yamaoka, Daiki Wakimoto, Makoto Watanabe
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Publication number: 20150308012Abstract: A method for growing a ?-Ga2O3-based single crystal, can provide a plate-shaped ?-Ga2O3-based single crystal having high crystal quality. In one embodiment, a method for growing a ?-Ga2O3-based single crystal employing an EFG method is provided, the method including: bringing a plate-shaped seed crystal into contact with a Ga2O3-based melt, wherein the plate-shaped seed crystal includes a ?-Ga2O3-based single crystal having a defect density of not more than 5×105/cm2 in the whole region; and pulling up the seed crystal to grow a ?-Ga2O3-based single crystal.Type: ApplicationFiled: October 9, 2013Publication date: October 29, 2015Inventors: Shinya WATANABE, Daiki WAKIMOTO, Kazuyuki IIZUKA, Kimiyoshi KOSHI, Takekazu MASUI
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Publication number: 20150249185Abstract: A ?-Ga2O3-based single crystal substrate includes a ?-Ga2O3-based single crystal. The ?-Ga2O3-based single crystal includes a full width at half maximum of an x-ray rocking curve of less than 75 seconds.Type: ApplicationFiled: February 26, 2015Publication date: September 3, 2015Inventors: Kimiyoshi KOSHI, Shinya Watanabe, Masaru Takizawa, Yu Yamaoka, Daiki Wakimoto, Makoto Watanabe
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Publication number: 20150155356Abstract: Provided is a semiconductor laminate structure including a Ga2O3 substrate and a nitride semiconductor layer with high crystal quality on the Ga2O3 substrate, and also provided is a semiconductor element including this semiconductor laminate structure. In one embodiment, this semiconductor laminate structure includes a ?-Ga2O3 substrate including ?-Ga2O3 crystal and a principal surface inclined from a (?201) surface to a [102] direction nd a nitride semiconductor layer including AlxGayInzN (0?x?1, 0?y?1, 0?z?1, x+y+z=1) crystal formed by epitaxial crystal growth on the principal surface of the ?-Ga2O3 substrate.Type: ApplicationFiled: May 27, 2013Publication date: June 4, 2015Applicants: TAMURA CORPORATIO9N, KOHA CO., LTDInventors: Kazuyuki Iizuka, Shinya Watanabe, Kimiyoshi Koshi, Daiki Wakimoto, Yoshihiro Yamashita, Shinkuro Sato