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).

  • Patent number: 11094537
    Abstract: 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: Grant
    Filed: February 11, 2020
    Date of Patent: August 17, 2021
    Assignee: 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
  • Patent number: 10837124
    Abstract: 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: Grant
    Filed: September 16, 2019
    Date of Patent: November 17, 2020
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Makoto Kiyama, Ryu Hirota, Seiji Nakahata
  • Publication number: 20200176305
    Abstract: 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: Application
    Filed: February 11, 2020
    Publication date: June 4, 2020
    Applicant: 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
  • Patent number: 10600676
    Abstract: 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: Grant
    Filed: January 24, 2018
    Date of Patent: March 24, 2020
    Assignee: 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
  • Publication number: 20200032419
    Abstract: 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: Application
    Filed: September 16, 2019
    Publication date: January 30, 2020
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Makoto KIYAMA, Ryu HIROTA, Seiji NAKAHATA
  • Patent number: 10458043
    Abstract: 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: Grant
    Filed: April 10, 2015
    Date of Patent: October 29, 2019
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Makoto Kiyama, Ryu Hirota, Seiji Nakahata
  • Patent number: 10443151
    Abstract: 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: Grant
    Filed: April 20, 2018
    Date of Patent: October 15, 2019
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Makoto Kiyama, Ryu Hirota, Seiji Nakahata
  • Patent number: 10078059
    Abstract: 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: Grant
    Filed: January 4, 2017
    Date of Patent: September 18, 2018
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Keiji Ishibashi, Tokiko Kaji, Seiji Nakahata, Takayuki Nishiura
  • Publication number: 20180237946
    Abstract: 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: Application
    Filed: April 20, 2018
    Publication date: August 23, 2018
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Makoto KIYAMA, Ryu HIROTA, Seiji NAKAHATA
  • Patent number: 10006147
    Abstract: 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: Grant
    Filed: April 16, 2015
    Date of Patent: June 26, 2018
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Makoto Kiyama, Ryu Hirota, Seiji Nakahata
  • Publication number: 20180166325
    Abstract: 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: Application
    Filed: January 24, 2018
    Publication date: June 14, 2018
    Applicant: 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
  • Patent number: 9917004
    Abstract: 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: Grant
    Filed: September 4, 2013
    Date of Patent: March 13, 2018
    Assignee: 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
  • Publication number: 20170137966
    Abstract: 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: Application
    Filed: April 10, 2015
    Publication date: May 18, 2017
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Makoto KIYAMA, Ryu HIROTA, Seiji NAKAHATA
  • Publication number: 20170115239
    Abstract: 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: Application
    Filed: January 4, 2017
    Publication date: April 27, 2017
    Inventors: Keiji ISHIBASHI, Tokiko KAJI, Seiji NAKAHATA, Takayuki NISHIURA
  • Publication number: 20170101724
    Abstract: 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: Application
    Filed: April 16, 2015
    Publication date: April 13, 2017
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Makoto KIYAMA, Ryu HIROTA, Seiji NAKAHATA
  • Patent number: 9570540
    Abstract: 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: Grant
    Filed: August 8, 2014
    Date of Patent: February 14, 2017
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Keiji Ishibashi, Tokiko Kaji, Seiji Nakahata, Takayuki Nishiura
  • Patent number: 9368568
    Abstract: 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: Grant
    Filed: August 27, 2014
    Date of Patent: June 14, 2016
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Koji Uematsu, Hideki Osada, Seiji Nakahata, Shinsuke Fujiwara
  • Patent number: 9252207
    Abstract: 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: Grant
    Filed: December 18, 2013
    Date of Patent: February 2, 2016
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Yoko Maeda, Fumitaka Sato, Akihiro Hachigo, Seiji Nakahata
  • Patent number: 9136337
    Abstract: 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: Grant
    Filed: September 18, 2013
    Date of Patent: September 15, 2015
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Keiji Ishibashi, Akihiro Hachigo, Yuki Hiromura, Naoki Matsumoto, Seiji Nakahata, Fumitake Nakanishi, Yusuke Yoshizumi, Hidenori Mikami
  • Publication number: 20150194442
    Abstract: 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: Application
    Filed: September 4, 2013
    Publication date: July 9, 2015
    Applicant: 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