Patents by Inventor Takamichi Sumitomo

Takamichi Sumitomo 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: 10938181
    Abstract: A vertical cavity surface emitting laser includes: an active layer including a quantum well structure including one or more well layers including a III-V compound semiconductor containing indium as a group III constituent element; an upper laminated region containing a carbon dopant; and a substrate for mounting a post including the active layer and the upper laminated region, in which the active layer is provided between the upper laminated region and the substrate, the quantum well structure has a carbon concentration of 2×1016 cm?3 or less, and the upper laminated region includes a pile-up layer of indium at a position away from the active layer.
    Type: Grant
    Filed: August 29, 2019
    Date of Patent: March 2, 2021
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Kei Fujii, Takamichi Sumitomo, Suguru Arikata
  • Patent number: 10594110
    Abstract: A vertical cavity surface emitting laser includes: a supporting base having a principal surface including III-V compound semiconductor containing gallium and arsenic as constituent elements; and a post disposed on the principal surface. The post has a lower spacer region including a III-V compound semiconductor containing gallium and arsenic as group-III elements, and an active layer having a quantum well structure disposed on the lower spacer region. The quantum well structure has a concentration of carbon in a range of 2×1016 cm?3 or more to 5×1016 cm?3 or less. The quantum well structure includes a well layer and a barrier layer. The well layer includes a III-V compound semiconductor containing indium as a group-III element, and the barrier layer includes a III-V compound semiconductor containing indium and aluminum as group-III elements. The lower spacer region is disposed between the supporting base and the active layer.
    Type: Grant
    Filed: November 13, 2018
    Date of Patent: March 17, 2020
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Kei Fujii, Toshiyuki Tanahashi, Takashi Ishizuka, Susumu Yoshimoto, Takamichi Sumitomo, Koji Nishizuka, Suguru Arikata
  • Publication number: 20200076161
    Abstract: A vertical cavity surface emitting laser includes: an active layer including a quantum well structure including one or more well layers including a III-V compound semiconductor containing indium as a group III constituent element; an upper laminated region containing a carbon dopant; and a substrate for mounting a post including the active layer and the upper laminated region, in which the active layer is provided between the upper laminated region and the substrate, the quantum well structure has a carbon concentration of 2×1016 cm?3 or less, and the upper laminated region includes a pile-up layer of indium at a position away from the active layer.
    Type: Application
    Filed: August 29, 2019
    Publication date: March 5, 2020
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Kei FUJII, Takamichi Sumitomo, Suguru Arikata
  • Publication number: 20200028328
    Abstract: A vertical cavity surface emitting laser includes an active layer having a quantum well structure, a first laminate for a first distributed Bragg reflector, and a first spacer region provided between the active layer and the first laminate. A barrier layer of the quantum well structure includes a first compound semiconductor containing aluminum as a group m constituent element. The first spacer region includes a second compound semiconductor having a larger aluminum composition than the first compound semiconductor. A concentration of first dopant in the first laminate is larger than a concentration of the first dopant in the first portion of the first spacer region. The concentration of the first dopant in the first portion of the first spacer region is larger than a concentration of the first dopant in the second portion of the first spacer region.
    Type: Application
    Filed: July 18, 2019
    Publication date: January 23, 2020
    Applicant: Sumitomo Electric Industries, LTD.
    Inventors: Suguru ARIKATA, Susumu YOSHIMOTO, Takamichi SUMITOMO, Kei FUJII
  • Publication number: 20190148914
    Abstract: A vertical cavity surface emitting laser includes: a supporting base having a principal surface including III-V compound semiconductor containing gallium and arsenic as constituent elements; and a post disposed on the principal surface. The post has a lower spacer region including a III-V compound semiconductor containing gallium and arsenic as group-III elements, and an active layer having a quantum well structure disposed on the lower spacer region. The quantum well structure has a concentration of carbon in a range of 2×1016 cm?3 or more to 5×1016 cm?3 or less. The quantum well structure includes a well layer and a barrier layer. The well layer includes a III-V compound semiconductor containing indium as a group-III element, and the barrier layer includes a III-V compound semiconductor containing indium and aluminum as group-III elements. The lower spacer region is disposed between the supporting base and the active layer.
    Type: Application
    Filed: November 13, 2018
    Publication date: May 16, 2019
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Kei Fujii, Toshiyuki Tanahashi, Takashi Ishizuka, Susumu Yoshimoto, Takamichi Sumitomo, Koji Nishizuka, Suguru Arikata
  • Publication number: 20190044306
    Abstract: A vertical cavity surface emitting laser includes: an active layer; a first laminate for a first distributed Bragg reflector; and a first intermediate layer disposed between the active layer and the first laminate. The first intermediate layer has first and second portions. The first laminate, the first and second portions of the first intermediate layer, and the active layer are arranged along a direction of a first axis. The first laminate and the first portion of the first intermediate layer each include a first dopant. The active layer has a first-dopant concentration of less than 1×1016 cm?3. The first portion of the first intermediate layer has a first-dopant concentration smaller than that of the first laminate. The second portion of the first intermediate layer has a first-dopant concentration smaller than that of the first portion of the first intermediate layer.
    Type: Application
    Filed: July 30, 2018
    Publication date: February 7, 2019
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Toshiyuki TANAHASHI, Takashi ISHIZUKA, Susumu YOSHIMOTO, Takamichi SUMITOMO, Koji NISHIZUKA, Kei FUJI, Suguru ARIKATA
  • Patent number: 9231370
    Abstract: A group III nitride semiconductor laser device includes a laser structure, an insulating layer, an electrode and dielectric multilayers. The laser structure includes a semiconductor region on a semi-polar primary surface of a hexagonal group III nitride semiconductor support base. The dielectric multilayers are on first and second end-faces for the laser cavity. The c-axis of the group III nitride tilts by an angle ALPHA from the normal axis of the primary surface in the waveguide axis direction from the first end-face to the second end-faces. A pad electrode has first to third portions provided on the first to third regions of the semiconductor regions, respectively. An ohmic electrode is in contact with the third region through an opening of the insulating layer. The first portion has a first arm, which extends to the first end-face edge. The third portion is away from the first end-face edge.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: January 5, 2016
    Assignees: Sumitomo Electric Industries, Ltd., SONY CORPORATION
    Inventors: Takamichi Sumitomo, Takashi Kyono, Masaki Ueno, Yusuke Yoshizumi, Yohei Enya, Masahiro Adachi, Shimpei Takagi, Katsunori Yanashima
  • Patent number: 8953656
    Abstract: A Group III nitride semiconductor laser device includes a laser structure including a support substrate with a semipolar primary surface of a hexagonal Group III nitride semiconductor, and a semiconductor region thereon, and an electrode, provided on the semiconductor region, extending in a direction of a waveguide axis in the laser device. The c-axis of the nitride semiconductor is inclined at an angle ALPHA relative to a normal axis to the semipolar surface toward the waveguide axis direction. The laser structure includes first and second fractured faces intersecting with the waveguide axis. A laser cavity of the laser device includes the first and second fractured faces extending from edges of first and second faces. The first fractured face includes a step provided at an end face of an InGaN layer of the semiconductor region and extending in a direction from one side face to the other of the laser device.
    Type: Grant
    Filed: January 19, 2012
    Date of Patent: February 10, 2015
    Assignees: Sumitomo Electric Industries, Ltd., Sony Corporation
    Inventors: Takashi Kyono, Shimpei Takagi, Takamichi Sumitomo, Yusuke Yoshizumi, Yohei Enya, Masaki Ueno, Katsunori Yanashima
  • Patent number: 8927962
    Abstract: A group III nitride semiconductor optical device 11a has a group III nitride semiconductor substrate 13 having a main surface 13a forming a finite angle with a reference plane Sc orthogonal to a reference axis Cx extending in a c-axis direction of the group III nitride semiconductor and an active layer 17 of a quantum-well structure, disposed on the main surface 13a of the group III nitride semiconductor substrate 13, including a well layer 28 made of a group III nitride semiconductor and a plurality of barrier layers 29 made of a group III nitride semiconductor. The main surface 13a exhibits semipolarity. The active layer 17 has an oxygen content of at least 1×1017 cm?3 but not exceeding 8×1017 cm?3. The plurality of barrier layers 29 contain an n-type impurity other than oxygen by at least 1×1017 cm?3 but not exceeding 1×1019 cm?3 in an upper near-interface area 29u in contact with a lower interface 28Sd of the well layer 28 on the group III nitride semiconductor substrate side.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: January 6, 2015
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Masaki Ueno, Yusuke Yoshizumi, Yohei Enya, Takashi Kyono, Katsushi Akita, Takamichi Sumitomo, Masahiro Adachi, Shinji Tokuyama
  • Patent number: 8923354
    Abstract: A nitride semiconductor laser comprises a conductive support base having a primary surface of gallium nitride based semiconductor, an active layer on the primary surface, and a p-type cladding region on the primary surface. The primary surface is tilted to a reference plane perpendicular to a reference axis extending in the c-axis direction of the gallium nitride based semiconductor. The p-type cladding region comprises a first p-type group III nitride semiconductor layer of an AlGaN layer anisotropically-strained, and a second p-type group III nitride semiconductor layer of material different from the AlGaN layer. The first p-type group III nitride semiconductor layer is provided between the second p-type group III nitride semiconductor layer and the active layer. The AlGaN layer has the largest bandgap in the p-type cladding region. The second p-type group III nitride semiconductor layer has a resistivity lower than the first p-type group III nitride semiconductor layer.
    Type: Grant
    Filed: October 4, 2012
    Date of Patent: December 30, 2014
    Inventors: Takashi Kyono, Yohei Enya, Takamichi Sumitomo, Yusuke Yoshizumi, Masaki Ueno, Katsunori Yanashima, Kunihiko Tasai, Hiroshi Nakajima
  • Patent number: 8809868
    Abstract: Provided is a Group III nitride semiconductor device, which comprises an electrically conductive substrate including a primary surface comprised of a first gallium nitride based semiconductor, and a Group III nitride semiconductor region including a first p-type gallium nitride based semiconductor layer and provided on the primary surface. The primary surface of the substrate is inclined at an angle in the range of not less than 50 degrees, and less than 130 degrees from a plane perpendicular to a reference axis extending along the c-axis of the first gallium nitride based semiconductor, an oxygen concentration Noxg of the first p-type gallium nitride based semiconductor layer is not more than 5×1017 cm?3, and a ratio (Noxg/Npd) of the oxygen concentration Noxg to a p-type dopant concentration Npd of the first p-type gallium nitride based semiconductor layer is not more than 1/10.
    Type: Grant
    Filed: November 4, 2011
    Date of Patent: August 19, 2014
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yohei Enya, Takashi Kyono, Takamichi Sumitomo, Yusuke Yoshizumi, Koji Nishizuka
  • Patent number: 8803274
    Abstract: A nitride-based semiconductor light-emitting element LE1 or LD1 has: a gallium nitride substrate 11 having a principal surface 11a which makes an angle ?, in the range 40° to 50° or in the range more than 90° to 130°, with the reference plane Sc perpendicular to the reference axis Cx extending in the c axis direction; an n-type gallium nitride-based semiconductor layer 13; a second gallium nitride-based semiconductor layer 17; and a light-emitting layer 15 including a plurality of well layers of InGaN and a plurality of barrier layers 23 of a GaN-based semiconductor, wherein the direction of piezoelectric polarization of the plurality of well layers 21 is the direction from the n-type gallium nitride-based semiconductor layer 13 toward the second gallium nitride-based semiconductor layer 17.
    Type: Grant
    Filed: June 18, 2010
    Date of Patent: August 12, 2014
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takashi Kyono, Yohei Enya, Yusuke Yoshizumi, Katsushi Akita, Masaki Ueno, Takamichi Sumitomo, Masahiro Adachi, Shinji Tokuyama
  • Patent number: 8748868
    Abstract: For a nitride semiconductor light emitting device, a c-axis vector of hexagonal GaN of a support substrate is inclined to an X-axis direction with respect to a normal axis Nx normal to a primary surface. In a semiconductor region an active layer, a first gallium nitride-based semiconductor layer, an electron block layer, and a second gallium nitride-based semiconductor layer are arranged along the normal axis on the primary surface of the support substrate. A p-type cladding layer is comprised of AlGaN, and the electron block layer is comprised of AlGaN. The electron block layer is subject to tensile strain in the X-axis direction. The first gallium nitride-based semiconductor layer is subject to compressive strain in the X-axis direction. The misfit dislocation density at an interface is smaller than that at an interface. A barrier to electrons at the interface is raised by piezoelectric polarization.
    Type: Grant
    Filed: November 10, 2011
    Date of Patent: June 10, 2014
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takashi Kyono, Yohei Enya, Katsushi Akita, Masaki Ueno, Yusuke Yoshizumi, Takamichi Sumitomo
  • Patent number: 8741674
    Abstract: Provided is a group-III nitride semiconductor laser device with a laser cavity of high lasing yield, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface. In a laser structure, a first surface is opposite to a second surface. The first and second fractured faces extend from an edge of the first surface to an edge of the second surface. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.
    Type: Grant
    Filed: December 22, 2011
    Date of Patent: June 3, 2014
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yusuke Yoshizumi, Shimpei Takagi, Yohei Enya, Takashi Kyono, Masahiro Adachi, Masaki Ueno, Takamichi Sumitomo, Shinji Tokuyama, Koji Katayama, Takao Nakamura, Takatoshi Ikegami
  • Patent number: 8718110
    Abstract: A nitride semiconductor laser includes an electrically conductive support substrate with a primary surface of a gallium nitride based semiconductor, an active layer provided above the primary surface, and a p-type cladding region provided above the primary surface. The primary surface is inclined relative to a reference plane perpendicular to a reference axis extending in a direction of the c-axis of the gallium nitride based semiconductor. The p-type cladding region includes first and second p-type Group III nitride semiconductor layers. The first p-type semiconductor layer comprises an InAlGaN layer including built-in anisotropic strain. The second p-type semiconductor layer comprises semiconductor different from material of the InAlGaN layer. The first nitride semiconductor layer is provided between the second p-type semiconductor layer and the active layer. The second p-type semiconductor layer has a resistivity lower than that of the first p-type semiconductor layer.
    Type: Grant
    Filed: February 6, 2012
    Date of Patent: May 6, 2014
    Assignees: Sumitomo Electric Industries, Ltd., Sony Corporation
    Inventors: Takashi Kyono, Yohei Enya, Takamichi Sumitomo, Yusuke Yoshizumi, Masaki Ueno, Katsunori Yanashima, Kunihiko Tasai, Hiroshi Nakajima
  • Patent number: 8693515
    Abstract: Provided is a group-III nitride semiconductor laser device with a laser cavity allowing for a low threshold current, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces 27, 29 to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device 11 has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface 17a. For this reason, it is feasible to make use of emission by a band transition enabling the low threshold current. In a laser structure 13, a first surface 13a is opposite to a second surface 13b. The first and second fractured faces 27, 29 extend from an edge 13c of the first surface 13a to an edge 13d of the second surface 13b. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.
    Type: Grant
    Filed: March 17, 2011
    Date of Patent: April 8, 2014
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yusuke Yoshizumi, Yohei Enya, Takashi Kyono, Masahiro Adachi, Katsushi Akita, Masaki Ueno, Takamichi Sumitomo, Shinji Tokuyama, Koji Katayama, Takao Nakamura, Takatoshi Ikegami
  • Patent number: 8653621
    Abstract: A nitride-based semiconductor light-emitting element LE1 or LD1 has: a gallium nitride substrate 11 having a principal surface 11a which makes an angle ?, in the range 40° to 50° or in the range more than 90° to 130°, with the reference plane Sc perpendicular to the reference axis Cx extending in the c axis direction; an n-type gallium nitride-based semiconductor layer 13; a second gallium nitride-based semiconductor layer 17; and a light-emitting layer 15 including a plurality of well layers of InGaN and a plurality of barrier layers 23 of a GaN-based semiconductor, wherein the direction of piezoelectric polarization of the plurality of well layers 21 is the direction from the n-type gallium nitride-based semiconductor layer 13 toward the second gallium nitride-based semiconductor layer 17.
    Type: Grant
    Filed: June 18, 2010
    Date of Patent: February 18, 2014
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takashi Kyono, Yohei Enya, Yusuke Yoshizumi, Katsushi Akita, Masaki Ueno, Takamichi Sumitomo, Masahiro Adachi, Shinji Tokuyama
  • Patent number: 8619828
    Abstract: A group III nitride substrate has a semi-polar primary surface. A first cladding layer has a first conductivity type, and comprises aluminum-containing group III nitride. The first cladding layer is provided on the substrate. An active layer is provided on the first cladding layer. A second cladding layer has a second conductivity type, and comprises aluminum-containing group III nitride. The second cladding layer is provided on the active layer. An optical guiding layer is provided between the first cladding layer and the active layer and/or between the second cladding layer and the active layer. The optical guiding layer comprises a first layer comprising Inx1Ga1-x1N (0?x1<1) and a second layer comprising Inx2Ga1-x2N (x1<x2<1). The second layer is provided between the first layer and the active layer. The total thickness of the first layer and the second layer is greater than 0.1 ?m. The wavelength of laser light is in a range of 480 nm to 550 nm.
    Type: Grant
    Filed: July 14, 2010
    Date of Patent: December 31, 2013
    Assignee: Sumitomo Electronic Industries, Ltd.
    Inventors: Katsushi Akita, Yohei Enya, Takashi Kyono, Masahiro Adachi, Shinji Tokuyama, Yusuke Yoshizumi, Takamichi Sumitomo, Masaki Ueno
  • Publication number: 20130295704
    Abstract: Provided is a group-III nitride semiconductor laser device with a laser cavity of high lasing yield, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface. In a laser structure, a first surface is opposite to a second surface. The first and second fractured faces extend from an edge of the first surface to an edge of the second surface. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.
    Type: Application
    Filed: December 22, 2011
    Publication date: November 7, 2013
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Yusuke YOSHIZUMI, Shimpei TAKAGI, Yohei ENYA, Takashi KYONO, Masahiro ADACHI, Masaki UENO, Takamichi SUMITOMO, Shinji TOKUYAMA, Koji KATAYAMA, Takao NAKAMURA, Takatoshi IKEGAMI
  • Publication number: 20130285066
    Abstract: Provided is a method of fabricating a gallium nitride semiconductor which enables activation of a p-type dopant with a heat treatment performed for a relatively short period of time. The fabricating method comprises the step of performing, in a vacuum, a heat treatment of a group III nitride semiconductor region, the group III nitride semiconductor region comprising a gallium nitride semiconductor, the gallium nitride semiconductor including a p-type dopant, the a group III nitride semiconductor region having a group III nitride semiconductor surface inclined with respect to a reference plane perpendicular to a reference axis, and the reference axis extending in a direction of a c-axis of the gallium nitride semiconductor.
    Type: Application
    Filed: April 26, 2013
    Publication date: October 31, 2013
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Takamichi SUMITOMO, Masaki UENO, Yusuke YOSHIZUMI, Yohei ENYA