Patents by Inventor Seiji Nakahata
Seiji Nakahata 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: 11094537Abstract: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. A group III nitride composite substrate includes a group III nitride film and a support substrate formed from a material different in chemical composition from the group III nitride film. The group III nitride film is joined to the support substrate in one of a direct manner and an indirect manner. The group III nitride film has a thickness of 10 ?m or more. A sheet resistance of a group III-nitride-film-side main surface is 200 ?/sq or less.Type: GrantFiled: February 11, 2020Date of Patent: August 17, 2021Assignee: Sumitomo Electric Industries, Ltd.Inventors: Keiji Ishibashi, Akihiro Hachigo, Yuki Hiromura, Naoki Matsumoto, Seiji Nakahata, Fumitake Nakanishi, Takuya Yanagisawa, Koji Uematsu, Yuki Seki, Yoshiyuki Yamamoto, Yusuke Yoshizumi, Hidenori Mikami
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Patent number: 10837124Abstract: A gallium nitride substrate has a surface with a diameter of not less than 100 mm, a difference being not less than 0.1 cm?1 and not more than 2 cm?1 between maximum and minimum values of wave numbers at a maximum peak of peaks corresponding to an E2H phonon mode in micro-Raman scattering mapping measurement at each of square regions having sides each having a length of 2 mm, the square regions being located at a total of five locations including a central location and four circumferential edge locations on the surface of the gallium nitride substrate, a difference being not more than 2 cm?1 between maximum and minimum values of the wave numbers at the maximum peak of the peaks corresponding to the E2H phonon mode at all of measurement points in the five locations.Type: GrantFiled: September 16, 2019Date of Patent: November 17, 2020Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Makoto Kiyama, Ryu Hirota, Seiji Nakahata
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Publication number: 20200176305Abstract: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. A group III nitride composite substrate includes a group III nitride film and a support substrate formed from a material different in chemical composition from the group III nitride film. The group III nitride film is joined to the support substrate in one of a direct manner and an indirect manner. The group III nitride film has a thickness of 10 ?m or more. A sheet resistance of a group III-nitride-film-side main surface is 200 ?/sq or less.Type: ApplicationFiled: February 11, 2020Publication date: June 4, 2020Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Keiji ISHIBASHI, Akihiro HACHIGO, Yuki HIROMURA, Naoki MATSUMOTO, Seiji NAKAHATA, Fumitake NAKANISHI, Takuya YANAGISAWA, Koji UEMATSU, Yuki SEKI, Yoshiyuki YAMAMOTO, Yusuke YOSHIZUMI, Hidenori MIKAMI
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Patent number: 10600676Abstract: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. A group III nitride composite substrate includes a group III nitride film and a support substrate formed from a material different in chemical composition from the group III nitride film. The group III nitride film is joined to the support substrate in one of a direct manner and an indirect manner. The group III nitride film has a thickness of 10 ?m or more. A sheet resistance of a group III-nitride-film-side main surface is 200 ?/sq or less.Type: GrantFiled: January 24, 2018Date of Patent: March 24, 2020Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Keiji Ishibashi, Akihiro Hachigo, Yuki Hiromura, Naoki Matsumoto, Seiji Nakahata, Fumitake Nakanishi, Takuya Yanagisawa, Koji Uematsu, Yuki Seki, Yoshiyuki Yamamoto, Yusuke Yoshizumi, Hidenori Mikami
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Publication number: 20200032419Abstract: A gallium nitride substrate has a surface with a diameter of not less than 100 mm, a difference being not less than 0.1 cm?1 and not more than 2 cm?1 between maximum and minimum values of wave numbers at a maximum peak of peaks corresponding to an E2H phonon mode in micro-Raman scattering mapping measurement at each of square regions having sides each having a length of 2 mm, the square regions being located at a total of five locations including a central location and four circumferential edge locations on the surface of the gallium nitride substrate, a difference being not more than 2 cm?1 between maximum and minimum values of the wave numbers at the maximum peak of the peaks corresponding to the E2H phonon mode at all of measurement points in the five locations.Type: ApplicationFiled: September 16, 2019Publication date: January 30, 2020Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Makoto KIYAMA, Ryu HIROTA, Seiji NAKAHATA
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Patent number: 10458043Abstract: A gallium nitride substrate has a surface with a diameter of not less than 100 mm, a difference being not less than 0.1 cm?1 and not more than 2 cm?1 between maximum and minimum values of wave numbers at a maximum peak of peaks corresponding to an E2H phonon mode in micro-Raman scattering mapping measurement at each of square regions having sides each having a length of 2 mm, the square regions being located at a total of five locations including a central location and four circumferential edge locations on the surface of the gallium nitride substrate, a difference being not more than 2 cm?1 between maximum and minimum values of the wave numbers at the maximum peak of the peaks corresponding to the E2H phonon mode at all of measurement points in the five locations.Type: GrantFiled: April 10, 2015Date of Patent: October 29, 2019Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Makoto Kiyama, Ryu Hirota, Seiji Nakahata
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Patent number: 10443151Abstract: There is provided a gallium nitride substrate having a C plane as a surface with a diameter of not less than 100 mm, the gallium nitride substrate including first regions and second regions having different average values of band-edge emission intensities in a micro photoluminescence mapping at 25° C. in a square region located in the C plane and having sides each having a length of 2 mm, an average value Ibe1a of the band-edge emission intensities of the first regions and an average value Ibe2a of the band-edge emission intensities of the second regions satisfying the following relational expressions (I) and (II): Ibe1a>Ibe2a . . . (I) and 2.1?Ibe1a/Ibe2a?9.4 . . . (II).Type: GrantFiled: April 20, 2018Date of Patent: October 15, 2019Assignee: Sumitomo Electric Industries, Ltd.Inventors: Makoto Kiyama, Ryu Hirota, Seiji Nakahata
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Patent number: 10078059Abstract: A nitride crystal is characterized in that, in connection with plane spacing of arbitrary specific parallel crystal lattice planes of the nitride crystal obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of the crystal while X-ray diffraction conditions of the specific parallel crystal lattice planes are satisfied, a uniform distortion at a surface layer of the crystal represented by a value of |d1?d2|/d2 obtained from the plane spacing d1 at the X-ray penetration depth of 0.3 ?m and the plane spacing d2 at the X-ray penetration depth of 5 ?m is equal to or lower than 2.1×10?3.Type: GrantFiled: January 4, 2017Date of Patent: September 18, 2018Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Keiji Ishibashi, Tokiko Kaji, Seiji Nakahata, Takayuki Nishiura
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Publication number: 20180237946Abstract: There is provided a gallium nitride substrate having a C plane as a surface with a diameter of not less than 100 mm, the gallium nitride substrate including first regions and second regions having different average values of band-edge emission intensities in a micro photoluminescence mapping at 25° C. in a square region located in the C plane and having sides each having a length of 2 mm, an average value Ibe1a of the band-edge emission intensities of the first regions and an average value Ibe2a of the band-edge emission intensities of the second regions satisfying the following relational expressions (I) and (II): Ibe1a>Ibe2a . . . (I) and 2.1?Ibe1a/Ibe2a?9.4 . . . (II).Type: ApplicationFiled: April 20, 2018Publication date: August 23, 2018Applicant: Sumitomo Electric Industries, Ltd.Inventors: Makoto KIYAMA, Ryu HIROTA, Seiji NAKAHATA
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Patent number: 10006147Abstract: There is provided a gallium nitride substrate having a C plane as a surface with a diameter of not less than 100 mm, the gallium nitride substrate including first regions and second regions having different average values of band-edge emission intensities in a micro photoluminescence mapping at 25° C. in a square region located in the C plane and having sides each having a length of 2 mm, an average value Ibe1a of the band-edge emission intensities of the first regions and an average value Ibe2a of the band-edge emission intensities of the second regions satisfying the following relational expressions (I) and (II): Ibe1a>Ibe2a??(I) and 2.1?Ibe1a/Ibe2a?9.4??(II).Type: GrantFiled: April 16, 2015Date of Patent: June 26, 2018Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Makoto Kiyama, Ryu Hirota, Seiji Nakahata
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Publication number: 20180166325Abstract: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. A group III nitride composite substrate includes a group III nitride film and a support substrate formed from a material different in chemical composition from the group III nitride film. The group III nitride film is joined to the support substrate in one of a direct manner and an indirect manner. The group III nitride film has a thickness of 10 ?m or more. A sheet resistance of a group III-nitride-film-side main surface is 200 ?/sq or less.Type: ApplicationFiled: January 24, 2018Publication date: June 14, 2018Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Keiji ISHIBASHI, Akihiro HACHIGO, Yuki HIROMURA, Naoki MATSUMOTO, Seiji NAKAHATA, Fumitake NAKANISHI, Takuya YANAGISAWA, Koji UEMATSU, Yuki SEKI, Yoshiyuki YAMAMOTO, Yusuke YOSHIZUMI, Hidenori MIKAMI
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Patent number: 9917004Abstract: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. A group III nitride composite substrate includes a group III nitride film and a support substrate formed from a material different in chemical composition from the group III nitride film. The group III nitride film is joined to the support substrate in one of a direct manner and an indirect manner. The group III nitride film has a thickness of 10 ?m or more. A sheet resistance of a group III-nitride-film-side main surface is 200 ?/sq or less.Type: GrantFiled: September 4, 2013Date of Patent: March 13, 2018Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Keiji Ishibashi, Akihiro Hachigo, Yuki Hiromura, Naoki Matsumoto, Seiji Nakahata, Fumitake Nakanishi, Takuya Yanagisawa, Koji Uematsu, Yuki Seki, Yoshiyuki Yamamoto, Yusuke Yoshizumi, Hidenori Mikami
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Publication number: 20170137966Abstract: A gallium nitride substrate has a surface with a diameter of not less than 100 mm, a difference being not less than 0.1 cm?1 and not more than 2 cm?1 between maximum and minimum values of wave numbers at a maximum peak of peaks corresponding to an E2H phonon mode in micro-Raman scattering mapping measurement at each of square regions having sides each having a length of 2 mm, the square regions being located at a total of five locations including a central location and four circumferential edge locations on the surface of the gallium nitride substrate, a difference being not more than 2 cm?1 between maximum and minimum values of the wave numbers at the maximum peak of the peaks corresponding to the E2H phonon mode at all of measurement points in the five locations.Type: ApplicationFiled: April 10, 2015Publication date: May 18, 2017Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Makoto KIYAMA, Ryu HIROTA, Seiji NAKAHATA
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Publication number: 20170115239Abstract: A nitride crystal is characterized in that, in connection with plane spacing of arbitrary specific parallel crystal lattice planes of the nitride crystal obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of the crystal while X-ray diffraction conditions of the specific parallel crystal lattice planes are satisfied, a uniform distortion at a surface layer of the crystal represented by a value of |d1?d2|/d2 obtained from the plane spacing d1 at the X-ray penetration depth of 0.3 ?m and the plane spacing d2 at the X-ray penetration depth of 5 ?m is equal to or lower than 2.1×10?3.Type: ApplicationFiled: January 4, 2017Publication date: April 27, 2017Inventors: Keiji ISHIBASHI, Tokiko KAJI, Seiji NAKAHATA, Takayuki NISHIURA
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Publication number: 20170101724Abstract: There is provided a gallium nitride substrate having a C plane as a surface with a diameter of not less than 100 mm, the gallium nitride substrate including first regions and second regions having different average values of band-edge emission intensities in a micro photoluminescence mapping at 25° C. in a square region located in the C plane and having sides each having a length of 2 mm, an average value Ibe1a of the band-edge emission intensities of the first regions and an average value Ibe2a of the band-edge emission intensities of the second regions satisfying the following relational expressions (I) and (II): Ibe1a>Ibe2a . . . (I) and 2.1?Ibe1a/Ibe2a?9.4 . . . (II).Type: ApplicationFiled: April 16, 2015Publication date: April 13, 2017Applicant: Sumitomo Electric Industries, Ltd.Inventors: Makoto KIYAMA, Ryu HIROTA, Seiji NAKAHATA
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Patent number: 9570540Abstract: A nitride crystal is characterized in that, in connection with plane spacing of arbitrary specific parallel crystal lattice planes of the nitride crystal obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of the crystal while X-ray diffraction conditions of the specific parallel crystal lattice planes are satisfied, a uniform distortion at a surface layer of the crystal represented by a value of |d1?d2|/d2 obtained from the plane spacing d1 at the X-ray penetration depth of 0.3 ?m and the plane spacing d2 at the X-ray penetration depth of 5 ?m is equal to or lower than 2.1×10?3.Type: GrantFiled: August 8, 2014Date of Patent: February 14, 2017Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Keiji Ishibashi, Tokiko Kaji, Seiji Nakahata, Takayuki Nishiura
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Patent number: 9368568Abstract: Group III nitride crystal produced by cutting, from III nitride bulk crystal, a plurality of Group III nitride crystal substrates with major-surface plane orientation misoriented five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20-21}, {20-2-1}, {22-41}, and {22-4-1}, transversely arranging the substrates adjacent to each other such that their major surfaces are parallel to each other and such that their [0001] directions coincide with each other, and growing a Group III nitride crystal on the major surfaces. The Group III nitride crystal substrates are further characterized by satisfying at least either an oxygen-atom concentration of 1×1016 cm?3 to 4×1019 cm?3 or a silicon-atom concentration of 6×1014 cm?3 to 5×1018 cm?3, and by having a carrier concentration of 1×1016 cm?3 to 6×1019 cm?3.Type: GrantFiled: August 27, 2014Date of Patent: June 14, 2016Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Koji Uematsu, Hideki Osada, Seiji Nakahata, Shinsuke Fujiwara
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Patent number: 9252207Abstract: An epitaxial-deposition composite substrate, of more than about 50 mm diameter, in which a nitride-compound semiconductor first substrate is bonded together with a second substrate of either identical or different material. The first substrate is ion-implanted, and on its nitrogen-face side is coated with a special film of thickness within a predetermined range. On a bonding side of the second substrate a special coating of thickness within the predetermined range is formed. The join created by the coated nitrogen-face side of the first substrate being bonded to the coated bonding side of the second substrate occupies at least 90% of the surface area where the two substrates meet.Type: GrantFiled: December 18, 2013Date of Patent: February 2, 2016Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yoko Maeda, Fumitaka Sato, Akihiro Hachigo, Seiji Nakahata
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Patent number: 9136337Abstract: A group III nitride composite substrate includes a support substrate and a group III nitride film. A ratio st/mt of a standard deviation st of the thickness of the group III nitride film, to a mean value mt of the thickness thereof is 0.001 or more and 0.2 or less, and a ratio so/mo of a standard deviation so of an absolute value of an off angle between a main surface of the group III nitride film and a plane of a predetermined plane orientation, to a mean value mo of the absolute value of the off angle thereof is 0.005 or more and 0.6 or less. Accordingly, there is provided a low-cost and large-diameter group III nitride composite substrate including a group III nitride film having a large thickness, a small thickness variation, and a high crystal quality.Type: GrantFiled: September 18, 2013Date of Patent: September 15, 2015Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Keiji Ishibashi, Akihiro Hachigo, Yuki Hiromura, Naoki Matsumoto, Seiji Nakahata, Fumitake Nakanishi, Yusuke Yoshizumi, Hidenori Mikami
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Publication number: 20150194442Abstract: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. A group III nitride composite substrate includes a group III nitride film and a support substrate formed from a material different in chemical composition from the group III nitride film. The group III nitride film is joined to the support substrate in one of a direct manner and an indirect manner. The group III nitride film has a thickness of 10 ?m or more. A sheet resistance of a group III-nitride-film-side main surface is 200 ?/sq or less.Type: ApplicationFiled: September 4, 2013Publication date: July 9, 2015Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTDInventors: Keiji Ishibashi, Akihiro Hachigo, Yuki Hiromura, Naoki Matsumoto, Seiji Nakahata, Fumitake Nakanishi, Takuya Yanagisawa, Koji Uematsu, Yuki Seki, Yoshiyuki Yamamoto, Yusuke Yoshizumi, Hidenori Mikami