Patents by Inventor Yusuke Yoshizumi

Yusuke Yoshizumi 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).

  • Publication number: 20130051417
    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: Application
    Filed: April 23, 2012
    Publication date: February 28, 2013
    Applicants: SONY CORPORATION, SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Takamichi SUMITOMO, Takashi KYONO, Masaki UENO, Yusuke YOSHIZUMI, Yohei ENYA, Masahiro ADACHI, Shimpei TAKAGI, Katsunori YANASHIMA
  • Publication number: 20130051418
    Abstract: A group-III nitride semiconductor laser device includes an n-type nitride semiconductor region, an active layer provided over the n-type nitride semiconductor region, a first p-type nitride semiconductor region provided over the active layer, a current confinement layer which is provided over the first p-type nitride semiconductor region and has an opening extending in a optical cavity direction, and a second p-type nitride semiconductor region re-grown on the first nitride semiconductor region and the current confinement layer after the formation of the opening of the current confinement layer. The interface between the first p-type nitride semiconductor region and the second p-type nitride semiconductor region includes a semi-polar plane. At least one of the first or second p-type semiconductor regions includes a highly doped p-type semiconductor layer forming an interface with the first and second p-type semiconductor regions and have a p-type impurity level of 1×1020 cm?3 or greater.
    Type: Application
    Filed: July 24, 2012
    Publication date: February 28, 2013
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Takamichi SUMITOMO, Masaki UENO, Yusuke YOSHIZUMI, Takahisa YOSHIDA, Masahiro ADACHI
  • Patent number: 8361885
    Abstract: A method of fabricating group-III nitride semiconductor laser device includes: preparing a substrate comprising a hexagonal group-III nitride semiconductor and having a semipolar principal surface; forming a substrate product having a laser structure, an anode electrode, and a cathode electrode, where the laser structure includes a semiconductor region and the substrate, where the semiconductor region is formed on the semipolar principal surface; scribing a first surface of the substrate product in a direction of an a-axis of the hexagonal group-III nitride semiconductor to form first and second scribed grooves; and carrying out breakup of the substrate product by press against a second surface of the substrate product, to form another substrate product and a laser bar.
    Type: Grant
    Filed: November 18, 2011
    Date of Patent: January 29, 2013
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yusuke Yoshizumi, Shimpei Takagi, Takatoshi Ikegami, Masaki Ueno, Koji Katayama
  • Patent number: 8357946
    Abstract: Provided is a nitride semiconductor light emitting device including a light emitting layer above a GaN support base with a semipolar surface and allowing for suppression of reduction in luminous efficiency due to misfit dislocations. A nitride semiconductor light emitting device 11 has a support base 13 comprised of a hexagonal gallium nitride, an n-type gallium nitride-based semiconductor layer 15 including an InX1AlY1Ga1-X1-Y1N (0<X1<1, 0<Y1<1, X1+Y1<1) layer 21, a light emitting layer 17, and a p-type gallium nitride-based semiconductor layer 19. This InAlGaN layer 21 is provided between a semipolar primary surface 13a and the light emitting layer 17. Since the bandgap E of the InAlGaN layer 21 is not less than the bandgap E of gallium nitride, a confinement effect of carriers and light in the light emitting layer 17 is provided.
    Type: Grant
    Filed: July 22, 2011
    Date of Patent: January 22, 2013
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takashi Kyono, Yusuke Yoshizumi, Yohei Enya, Katsushi Akita, Masaki Ueno, Takamichi Sumitomo
  • Patent number: 8357558
    Abstract: A method of making a semiconductor light-emitting device involves the steps of selecting at least one tilt angle for a primary surface of a substrate to evaluate the direction of piezoelectric polarization in a light-emitting layer, the substrate comprising a group III nitride semiconductor; preparing a substrate having the primary surface, the primary surface having the selected tilt angle, and the primary surface comprising the group III nitride semiconductor; forming a quantum well structure and p- and n-type gallium nitride semiconductor layers for the light-emitting layer at the selected tilt angle to prepare a substrate product; measuring photoluminescence of the substrate product while applying a bias to the substrate product, to determine bias dependence of the photoluminescence; evaluating the direction of the piezoelectric polarization in the light-emitting layer at the selected tilt angle on the primary surface of the substrate by the determined bias dependence; determining which of the primary sur
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: January 22, 2013
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takashi Kyono, Yohei Enya, Yusuke Yoshizumi, Katsushi Akita, Masaki Ueno, Takamichi Sumitomo, Masahiro Adachi, Shinji Tokuyama
  • Publication number: 20130009202
    Abstract: A group-III nitride semiconductor device includes a light emitting layer emitting light of a wavelength in the range of 480 to 600 nm; a first contact layer over the light emitting layer; a second contact layer in direct contact with the first contact layer; and a metal electrode in direct contact with the second contact layer. The first and second contact layers comprise a p-type gallium nitride-based semiconductor. The p-type dopant concentration of the first contact layer is lower than that of the second contact layer. The light emitting layer comprises a gallium nitride-based semiconductor. The interface between the first and second contact layers tilts at an angle of not less than 50 degrees and smaller than 130 degrees from a plane orthogonal to a reference axis extending along the c-axis. The second contact layer has a thickness within the range of 1 to 50 nm.
    Type: Application
    Filed: June 29, 2012
    Publication date: January 10, 2013
    Applicants: SONY CORPORATION, SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Yohei ENYA, Yusuke YOSHIZUMI, Takashi KYONO, Takamichi SUMITOMO, Masaki UENO, Katsunori YANASHIMA, Kunihiko TASAI, Hiroshi NAKAJIMA
  • Publication number: 20120327967
    Abstract: A nitride semiconductor laser device includes a p-type cladding layer, an active layer and an n-type cladding layer. The p-type cladding layer and the n-type cladding layer comprise indium and aluminum as group-III constituent. The n-type cladding layer, active layer and p-type cladding layer are arranged along the normal of a semi-polar semiconductor surface of a substrate. This surface tilts toward the m-axis of the hexagonal nitride by an angle of 63 degrees or more and smaller than 80 degrees from a plane orthogonal to a reference axis extending along the c-axis thereof. The active layer generates light having a peak wavelength in the range of 480 to 600 nm. The refractive indices of the n-type cladding layer and p-type cladding layer are smaller than that of GaN. The n-type cladding layer has a thickness of 2 ?m or more while the p-type cladding layer has a thickness of 500 nm or more.
    Type: Application
    Filed: May 24, 2012
    Publication date: December 27, 2012
    Applicants: SONY CORPORATION, SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Yohei ENYA, Yusuke YOSHIZUMI, Takashi KYONO, Takamichi SUMITOMO, Masaki UENO, Katsunori YANASHIMA, Kunihiko TASAI, Hiroshi NAKAJIMA
  • Publication number: 20120299010
    Abstract: A III-nitride semiconductor device has a support base comprised of a III-nitride semiconductor and having a primary surface extending along a first reference plane perpendicular to a reference axis inclined at a predetermined angle with respect to a c-axis of the III-nitride semiconductor, and an epitaxial semiconductor region provided on the primary surface of the support base. The epitaxial semiconductor region includes GaN-based semiconductor layers. The reference axis is inclined at a first angle from the c-axis of the III-nitride semiconductor toward a first crystal axis, either the m-axis or a-axis. The reference axis is inclined at a second angle from the c-axis of the III-nitride semiconductor toward a second crystal axis, the other of the m-axis and a-axis. Morphology of an outermost surface of the epitaxial semiconductor region includes a plurality of pits. A pit density of the pits is not more than 5×104 cm?2.
    Type: Application
    Filed: May 31, 2012
    Publication date: November 29, 2012
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Yohei ENYA, Yusuke Yoshizumi, Takashi Kyono, Takamichi Sumitomo, Katsushi Akita, Masaki Ueno, Takao Nakamura
  • Patent number: 8304269
    Abstract: A group III nitride semiconductor device having a gallium nitride based semiconductor film with an excellent surface morphology is provided. A group III nitride optical semiconductor device 11a includes a group III nitride semiconductor supporting base 13, a GaN based semiconductor region 15, an active layer active layer 17, and a GaN semiconductor region 19. The primary surface 13a of the group III nitride semiconductor supporting base 13 is not any polar plane, and forms a finite angle with a reference plane Sc that is orthogonal to a reference axis Cx extending in the direction of a c-axis of the group III nitride semiconductor. The GaN based semiconductor region 15 is grown on the semipolar primary surface 13a. A GaN based semiconductor layer 21 of the GaN based semiconductor region 15 is, for example, an n-type GaN based semiconductor, and the n-type GaN based semiconductor is doped with silicon.
    Type: Grant
    Filed: May 20, 2011
    Date of Patent: November 6, 2012
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takashi Kyono, Yusuke Yoshizumi, Yohei Enya, Katsushi Akita, Masaki Ueno, Takamichi Sumitomo, Takao Nakamura
  • Patent number: 8306082
    Abstract: A group-III nitride semiconductor laser device comprises a laser structure including a support base and a semiconductor region, and an electrode provided on the semiconductor region of the laser structure. The support base comprises a hexagonal group-III nitride semiconductor and has a semipolar primary surface, and the semiconductor region is provided on the semipolar primary surface of the support base. The semiconductor region includes a first cladding layer of a first conductivity type gallium nitride-based semiconductor, a second cladding layer of a second conductivity type gallium nitride-based semiconductor, and an active layer. The first cladding layer, the second cladding layer, and the active layer are arranged along a normal axis to the semipolar primary surface. The active layer comprises a gallium nitride-based semiconductor layer.
    Type: Grant
    Filed: July 29, 2010
    Date of Patent: November 6, 2012
    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: 8304793
    Abstract: A III-nitride semiconductor optical device has a support base comprised of a III-nitride semiconductor, an n-type gallium nitride based semiconductor layer, a p-type gallium nitride based semiconductor layer, and an active layer. The support base has a primary surface at an angle with respect to a reference plane perpendicular to a reference axis extending in a c-axis direction of the III-nitride semiconductor. The n-type gallium nitride based semiconductor layer is provided over the primary surface of the support base. The p-type gallium nitride based semiconductor layer is doped with magnesium and is provided over the primary surface of the support base. The active layer is provided between the n-type gallium nitride based semiconductor layer and the p-type gallium nitride based semiconductor layer over the primary surface of the support base. The angle is in the range of not less than 40° and not more than 140°. The primary surface demonstrates either one of semipolar nature and nonpolar nature.
    Type: Grant
    Filed: July 14, 2010
    Date of Patent: November 6, 2012
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yusuke Yoshizumi, Yohei Enya, Katsushi Akita, Masaki Ueno, Takashi Kyono, Takao Nakamura
  • Publication number: 20120267606
    Abstract: A group III nitride crystal substrate is provided, wherein, a uniform distortion at a surface layer of the crystal substrate is equal to or lower than 1.7×10?3, and wherein a plane orientation of the main surface has an inclination angle equal to or greater than ?10° and equal to or smaller than 10° in a [0001] direction with respect to a plane including a c axis of the crystal substrate. A group III nitride crystal substrate suitable for manufacturing a light emitting device with a blue shift of an emission suppressed, an epilayer-containing group III nitride crystal substrate, a semiconductor device and a method of manufacturing the same can thereby be provided.
    Type: Application
    Filed: June 18, 2012
    Publication date: October 25, 2012
    Inventors: Keiji ISHIBASHI, Yusuke Yoshizumi, Shugo Minobe
  • Publication number: 20120269222
    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: Application
    Filed: February 6, 2012
    Publication date: October 25, 2012
    Applicants: SONY CORPORATION, SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Takashi KYONO, Yohei ENYA, Takamichi SUMITOMO, Yusuke YOSHIZUMI, Masaki UENO, Katsunori YANASHIMA, Kunihiko TASAI, Hiroshi NAKAJIMA
  • Publication number: 20120269220
    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: Application
    Filed: January 19, 2012
    Publication date: October 25, 2012
    Applicants: SONY CORPORATION, SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Takashi KYONO, Shimpei TAKAGI, Takamichi SUMITOMO, Yusuke YOSHIZUMI, Yohei ENYA, Masaki UENO, Katsunori YANASHIMA
  • Publication number: 20120258557
    Abstract: A III-nitride semiconductor laser device is provided with a laser structure and an electrode. The laser structure includes a support base which includes a hexagonal III-nitride semiconductor and a semipolar primary surface, and a semiconductor region provided on the semipolar primary surface. The electrode is provided on the semiconductor region. The semiconductor region includes a first cladding layer of a first conductivity type GaN-based semiconductor, a second cladding layer of a second conductivity type GaN-based semiconductor, and an active layer provided between the first cladding layer and the second cladding layer.
    Type: Application
    Filed: April 10, 2012
    Publication date: October 11, 2012
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Yusuke Yoshizumi, Yohei Enya, Takashi Kyono, Takamichi Sumitomo, Nobuhiro Saga, Masahiro Adachi, Kazuhide Sumiyoshi, Shinji Tokuyama, Shimpei Takagi, Takatoshi Ikegami, Masaki Ueno, Koji Katayama
  • Patent number: 8284811
    Abstract: Provided is a III-nitride semiconductor laser diode capable of lasing to emit light of not less than 500 nm with use of a semipolar plane. Since an active layer 29 is provided so as to generate light at the wavelength of not less than 500 nm, the wavelength of light to be confined into a core semiconductor region 19 is a long wavelength. A first optical guide layer 27 is provided with a two-layer structure, and a second optical guide layer 31 is provided with a two-layer structure.
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: October 9, 2012
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takamichi Sumitomo, Yohei Enya, Yusuke Yoshizumi, Masaki Ueno, Katsushi Akita, Takashi Kyono
  • Patent number: 8265113
    Abstract: In a III-nitride semiconductor laser device, a laser structure includes a support base comprised of a hexagonal III-nitride semiconductor and having a semipolar primary surface, and a semiconductor region provided on the semipolar primary surface of the support base. An electrode is provided on the semiconductor region of the laser structure.
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: September 11, 2012
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yusuke Yoshizumi, Shimpei Takagi, Takatoshi Ikegami, Masaki Ueno, Koji Katayama
  • Publication number: 20120223417
    Abstract: A group III nitride crystal substrate is provided wherein, a uniform distortion at a surface layer of the crystal substrate is equal to or lower than 1.9×10?3, and wherein the main surface has a plane orientation inclined in a <11-20> direction at an angle equal to or greater than 10° and equal to or smaller than 81° with respect to one of (0001) and (000-1) planes of the crystal substrate. A group III nitride crystal substrate suitable for manufacturing a light emitting device with a blue shift of an emission suppressed, an epilayer-containing group III nitride crystal substrate, a semiconductor device and a method of manufacturing the same can thereby be provided.
    Type: Application
    Filed: May 11, 2012
    Publication date: September 6, 2012
    Inventors: Keiji Ishibashi, Yusuke Yoshizumi
  • Publication number: 20120214268
    Abstract: A method of fabricating a III-nitride semiconductor laser device includes: preparing a substrate product, where the substrate product has a laser structure, the laser structure includes a semiconductor region and a substrate of a hexagonal III-nitride semiconductor, the substrate has a semipolar primary surface, and the semiconductor region is formed on the semipolar primary surface; scribing a first surface of the substrate product to form a scribed mark, the scribed mark extending in a direction of an a-axis of the hexagonal III-nitride semiconductor; and after forming the scribed mark, carrying out breakup of the substrate product by press against a second region of the substrate product while supporting a first region of the substrate product but not supporting the second region thereof, to form another substrate product and a laser bar.
    Type: Application
    Filed: February 24, 2012
    Publication date: August 23, 2012
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Shimpei TAKAGI, Yusuke Yoshizumi, Koji Katayama, Masaki Ueno, Takatoshi Ikegami
  • Publication number: 20120202304
    Abstract: A method of fabricating a III-nitride semiconductor laser device includes: preparing a substrate with a semipolar primary surface, the semipolar primary surface including a hexagonal III-nitride semiconductor; forming a substrate product having a laser structure, an anode electrode, and a cathode electrode, the laser structure including a substrate and a semiconductor region, and the semiconductor region being formed on the semipolar primary surface; after forming the substrate product, forming first and second end faces; and forming first and second dielectric multilayer films for an optical cavity of the nitride semiconductor laser device on the first and second end faces, respectively.
    Type: Application
    Filed: March 9, 2012
    Publication date: August 9, 2012
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Yusuke YOSHIZUMI, Yohei ENYA, Takashi KYONO, Masahiro ADACHI, Shinji TOKUYAMA, Takamichi SUMITOMO, Masaki UENO, Takatoshi IKEGAMI, Koji KATAYAMA, Takao NAKAMURA