Patents by Inventor Akinori Koukitu
Akinori Koukitu 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).
-
Patent number: 11982016Abstract: As one embodiment, the present invention provides a method for growing a ?-Ga2O3-based single crystal film by using HYPE method. The method includes a step of exposing a Ga2O3-based substrate to a gallium chloride-based gas and an oxygen-including gas, and growing a ?-Ga2O3-based single crystal film on a principal surface of the Ga2O3-based substrate at a growth temperature of not lower than 900° C.Type: GrantFiled: September 10, 2021Date of Patent: May 14, 2024Assignees: Tamura Corporation, National University Corporation Tokyo University of Agriculture and TechnologyInventors: Ken Goto, Kohei Sasaki, Akinori Koukitu, Yoshinao Kumagai, Hisashi Murakami
-
Patent number: 11499247Abstract: This disclosure provides a vapor-liquid reaction device including a vapor-liquid reaction chamber and a projecting member. The vapor-liquid reaction chamber holds a molten metal in a lower portion of an internal space of the vapor-liquid reaction chamber.Type: GrantFiled: May 17, 2018Date of Patent: November 15, 2022Assignees: National University Corporation Tokyo University of Agriculture and Technology, Taiyo Nippon Sanso Corporation, Taiyo Nippon Sanso CSE CorporationInventors: Akinori Koukitu, Hisashi Murakami, Akira Yamaguchi, Kazushige Shiina, Hayato Shimamura
-
Patent number: 11371140Abstract: A method for producing a GaN crystal that includes: (i) a seed crystal preparation step of preparing a GaN seed crystal having one or more facets selected from a {10-10} facet and a {10-1-1} facet; and (ii) a growth step of growing GaN from vapor phase on a surface comprising the one or more facets of the GaN seed crystal using GaCl3 and NH3 as raw materials.Type: GrantFiled: February 18, 2021Date of Patent: June 28, 2022Assignees: MITSUBISHI CHEMICAL CORPORATION, NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGYInventors: Kenji Iso, Akinori Koukitu, Hisashi Murakami
-
Publication number: 20210404086Abstract: As one embodiment, the present invention provides a method for growing a ?-Ga2O3-based single crystal film by using HYPE method. The method includes a step of exposing a Ga2O3-based substrate to a gallium chloride-based gas and an oxygen-including gas, and growing a ?-Ga2O3-based single crystal film on a principal surface of the Ga2O3-based substrate at a growth temperature of not lower than 900° C.Type: ApplicationFiled: September 10, 2021Publication date: December 30, 2021Applicants: TAMURA CORPORATION, NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGYInventors: Ken GOTO, Kohei SASAKI, Akinori KOUKITU, Yoshinao KUMAGAI, Hisashi MURAKAMI
-
Patent number: 11047067Abstract: [Problem] To provide a crystal laminate structure having a ?-Ga2O3 based single crystal film in which a dopant is included throughout the crystal and the concentration of the dopant can be set across a broad range. [Solution] In one embodiment of the present invention, provided is a crystal laminate structure 1 which includes: a Ga2O3 based substrate 10; and a ?-Ga2O3 based single crystal film 12 formed by epitaxial crystal growth on a primary face 11 of the Ga2O3 based substrate 10 and including Cl and a dopant doped in parallel with the crystal growth at a concentration of 1×1013 to 5.0×1020 atoms/cm3.Type: GrantFiled: December 3, 2019Date of Patent: June 29, 2021Assignees: TAMURA CORPORATION, NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGYInventors: Ken Goto, Akinori Koukitu, Yoshinao Kumagai, Hisashi Murakami
-
Publication number: 20210172061Abstract: A method for producing a GaN crystal that includes: (i) a seed crystal preparation step of preparing a GaN seed crystal having one or more facets selected from a {10-10} facet and a {10-1-1} facet; and (ii) a growth step of growing GaN from vapor phase on a surface comprising the one or more facets of the GaN seed crystal using GaCl3 and NH3 as raw materials.Type: ApplicationFiled: February 18, 2021Publication date: June 10, 2021Applicants: MITSUBISHI CHEMICAL CORPORATION, NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGYInventors: Kenji ISO, Akinori KOUKITU, Hisashi MURAKAMI
-
Patent number: 10961619Abstract: The present invention provides a novel method for producing a GaN crystal, the method including growing GaN from vapor phase on a semi-polar or non-polar GaN surface using GaCl3 and NH3 as raw materials. Provided herein is an invention of a method for producing a GaN crystal, including the steps of: (i) preparing a GaN seed crystal having a non-polar or semi-polar surface whose normal direction forms an angle of 85° or more and less than 170° with a [0001] direction of the GaN seed crystal; and (ii) growing GaN from vapor phase on a surface including the non-polar or semi-polar surface of the GaN seed crystal using GaCl3 and NH3 as raw materials.Type: GrantFiled: September 13, 2018Date of Patent: March 30, 2021Assignees: MITSUBISHI CHEMICAL CORPORATION, NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGYInventors: Kenji Iso, Akinori Koukitu, Hisashi Murakami
-
Patent number: 10861945Abstract: A semiconductor element includes a high-resistivity substrate that includes a ?-Ga2O3-based single crystal including an acceptor impurity, a buffer layer on the high-resistivity substrate, the buffer layer including a ?-Ga2O3-based single crystal, and a channel layer on the buffer layer, the channel layer including a ?-Ga2O3-based single crystal including a donor impurity. A crystalline laminate structure includes a high-resistivity substrate that includes a ?-Ga2O3-based single crystal including an acceptor impurity, a buffer layer on the high-resistivity substrate, the buffer layer including a ?-Ga2O3-based single crystal, and a donor impurity-containing layer on the buffer layer, the donor impurity-containing layer including a ?-Ga2O3-based single crystal including a donor impurity.Type: GrantFiled: August 18, 2015Date of Patent: December 8, 2020Assignees: TAMURA CORPORATION, NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY, NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGYInventors: Kohei Sasaki, Ken Goto, Masataka Higashiwaki, Man Hoi Wong, Akinori Koukitu, Yoshinao Kumagai, Hisashi Murakami
-
Publication number: 20200255974Abstract: A method of manufacturing a crystalline gallium nitride film, including: a growth step in which a GaCl3 gas, a halogen gas, an NH3 gas, and a carrier gas consisting of one or more inert gases are supplied onto a substrate, thereby growing a crystalline gallium nitride film on the substrate, wherein a partial pressure ratio [PHalogen/PGaCl3] is defined as a ratio of a partial pressure of the halogen gas with respect to a partial pressure of the GaCl3 gas on the substrate in the growth step, and the partial pressure ratio [PHalogen/PGaCl3] is 0.20 or more.Type: ApplicationFiled: September 13, 2018Publication date: August 13, 2020Applicants: National University Corporation Tokyo University of Agriculture and Technology, Taiyo Nippon Sanso CorporationInventors: Akinori Koukitu, Hisashi Murakami, Akira Yamaguchi
-
Patent number: 10676841Abstract: A semiconductor substrate for being used as a base substrate for epitaxial crystal growth by HVPE method includes a ?-Ga2O3-based single crystal, and a principal surface that is a plane parallel to a [010] axis of the ?-Ga2O3-based single crystal. An epitaxial wafer includes the semiconductor substrate, and an epitaxial layer that includes a ?-Ga2O3-based single crystal and is formed on the principal surface of the semiconductor substrate by epitaxial crystal growth using the HVPE method. A method for manufacturing the epitaxial wafer includes forming the epitaxial layer by epitaxial crystal growth using the HVPE method on the semiconductor substrate.Type: GrantFiled: May 11, 2015Date of Patent: June 9, 2020Assignees: TAMURA CORPORATION, NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGYInventors: Ken Goto, Akinori Koukitu, Yoshinao Kumagai, Hisashi Murakami
-
Publication number: 20200102667Abstract: [Problem] To provide a crystal laminate structure having a ?-Ga2O3 based single crystal film in which a dopant is included throughout the crystal and the concentration of the dopant can be set across a broad range. [Solution] In one embodiment of the present invention, provided is a crystal laminate structure 1 which includes: a Ga2O3 based substrate 10; and a ?-Ga2O3 based single crystal film 12 formed by epitaxial crystal growth on a primary face 11 of the Ga2O3 based substrate 10 and including Cl and a dopant doped in parallel with the crystal growth at a concentration of 1×1013 to 5.0×1020 atoms/cm3.Type: ApplicationFiled: December 3, 2019Publication date: April 2, 2020Applicants: TAMURA CORPORATION, NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGYInventors: Ken GOTO, Akinori KOUKITU, Yoshinao KUMAGAI, Hisashi MURAKAMI
-
Publication number: 20200071848Abstract: This disclosure provides a vapor-liquid reaction device including a vapor-liquid reaction chamber and a projecting member. The vapor-liquid reaction chamber holds a molten metal in a lower portion of an internal space of the vapor-liquid reaction chamber.Type: ApplicationFiled: May 17, 2018Publication date: March 5, 2020Applicants: National University Corporation Tokyo University of Agriculture and Technology, Taiyo Nippon Sanso Corporation, Taiyo Nippon Sanso CSE CorporationInventors: Akinori Koukitu, Hisashi Murakami, Akira Yamaguchi, Kazushige Shiina, Hayato Shimamura
-
Patent number: 10538862Abstract: A crystal laminate structure includes a Ga2O3-based substrate, and a ?-Ga2O3-based single crystal film formed by epitaxial crystal growth on a principal surface of the Ga2O3-based substrate. The ?-Ga2O3-based single crystal film includes Cl and a dopant doped in parallel with the crystal growth at a concentration of not less than 1×1013 atoms/cm3 and not more than 5.0×1020 atoms/cm3.Type: GrantFiled: February 17, 2016Date of Patent: January 21, 2020Assignees: TAMURA CORPORATION, NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGYInventors: Ken Goto, Akinori Koukitu, Yoshinao Kumagai, Hisashi Murakami
-
Patent number: 10199512Abstract: A high withstand voltage Schottky barrier diode includes a first layer that includes a first Ga2O3-based single crystal including a first Group IV element and Cl at a concentration of not more than 5×1016 cm?3 and that has an effective donor concentration of not less than 1×1013 and not more than 6.0×1017 cm?3, a second layer that includes a second Ga2O3-based single crystal including a second Group IV element and that has a higher effective donor concentration than the first layer and is laminated on the first layer, an anode electrode formed on the first layer, and a cathode electrode formed on the second layer.Type: GrantFiled: March 9, 2016Date of Patent: February 5, 2019Assignees: TAMURA CORPORATION, NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY, NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGYInventors: Kohei Sasaki, Ken Goto, Masataka Higashiwaki, Akinori Koukitu, Yoshinao Kumagai, Hisashi Murakami
-
Publication number: 20190010605Abstract: The present invention provides a novel method for producing a GaN crystal, the method including growing GaN from vapor phase on a semi-polar or non-polar GaN surface using GaCl3 and NH3 as raw materials. Provided herein is an invention of a method for producing a GaN crystal, including the steps of: (i) preparing a GaN seed crystal having a non-polar or semi-polar surface whose normal direction forms an angle of 85° or more and less than 170° with a [0001] direction of the GaN seed crystal; and (ii) growing GaN from vapor phase on a surface including the non-polar or semi-polar surface of the GaN seed crystal using GaCl3 and NH3 as raw materials.Type: ApplicationFiled: September 13, 2018Publication date: January 10, 2019Applicants: MITSUBISHI CHEMICAL CORPORATION, NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGYInventors: Kenji ISO, Akinori KOUKITU, Hisashi MURAKAMI
-
Patent number: 10125433Abstract: A nitride semiconductor crystal has a diameter of four inches or more and is warped to have a curvature radius of 100 m or more, and has an impurity concentration of 1×1017/cm3 or lower. A manufacturing method for a nitride semiconductor crystal includes providing a substrate, feeding a gallium trihalide gas having a partial pressure of 9.0×10?3 atm or higher onto the substrate, and growing a GaN crystal in the ?C-axis direction on the substrate, where a growth temperature for the GaN crystal is 1200° C. or higher, or a manufacturing method for a nitride semiconductor crystal includes providing a substrate, feeding an aluminum trihalide gas having a partial pressure of 9.0×10?3 atm or higher onto the substrate, and growing an AlN crystal in the ?C-axis direction on the substrate, where a growth temperature for the AlN crystal is 1400° C. or higher.Type: GrantFiled: March 8, 2016Date of Patent: November 13, 2018Assignees: National University Corporation Tokyo, University of Agriculture and TechnologyInventors: Akinori Koukitu, Yoshinao Kumagai, Hisashi Murakami
-
Publication number: 20180269351Abstract: InGaN-based light-emitting devices fabricated on an InGaN template layer are disclosed.Type: ApplicationFiled: May 22, 2018Publication date: September 20, 2018Inventors: Michael R. Krames, Mark P. D'Evelyn, Akinori Koukitu, Yoshinao Kumagai, Hisashi Murakami
-
Publication number: 20180254355Abstract: A high withstand voltage Schottky barrier diode includes a first layer that includes a first Ga2O3-based single crystal including a first Group IV element and Cl at a concentration of not more than 5×1016 cm?3 and that has an effective donor concentration of not less than 1×1013 and not more than 6.0×1017 cm?3, a second layer that includes a second Ga2O3-based single crystal including a second Group IV element and that has a higher effective donor concentration than the first layer and is laminated on the first layer, an anode electrode formed on the first layer, and a cathode electrode formed on the second layer.Type: ApplicationFiled: March 9, 2016Publication date: September 6, 2018Applicants: TAMURA CORPORATION, National Institute of Information and Communications Technology, National University Corporation Tokyo University of Agriculture and TechnologyInventors: Kohei SASAKI, Ken GOTO, Masataka HIGASHIWAKI, Akinori KOUKITU, Yoshinao KUMAGAI, Hisashi MURAKAMI
-
Patent number: 10011921Abstract: To provide a method for producing a Group III element nitride crystal by growing it on a plane on the ?c-plane side as a crystal growth plane. The present invention is a method for producing a Group III element nitride crystal, including a vapor phase growth step of growing a Group III element nitride crystal 12 on a crystal growth plane of a Group III element nitride seed crystal 11 by vapor deposition. The vapor phase growth step is a step of causing a Group III metal, an oxidant, and a nitrogen-containing gas to react with one another to grow the Group III element nitride crystal 12 or includes: a reduced product gas generation step of causing a Group III element oxide and a reducing gas to react with each other to generate a gas of a reduced product of the Group III element oxide; and a crystal generation step of causing the gas of the reduced product and a nitrogen-containing gas to react with each other to generate the Group III element nitride crystal 12.Type: GrantFiled: October 28, 2015Date of Patent: July 3, 2018Assignees: Osaka University, Itochu Plastics Inc., National University Corporation Tokyo University of Agriculture and TechnologyInventors: Yusuke Mori, Masashi Yoshimura, Mamoru Imade, Masashi Isemura, Akinori Koukitu
-
Patent number: 9978904Abstract: InGaN-based light-emitting devices fabricated on an InGaN template layer are disclosed.Type: GrantFiled: October 15, 2013Date of Patent: May 22, 2018Assignee: Soraa, Inc.Inventors: Michael R. Krames, Mark P. D'Evelyn, Akinori Koukitu, Yoshinao Kumagai, Hisashi Murakami