Patents by Inventor Masahiro Adachi

Masahiro Adachi 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: 20120184057
    Abstract: A method of fabricating a III-nitride semiconductor laser device includes: preparing a substrate with a semipolar primary surface, where the semipolar primary surface includes a hexagonal III-nitride semiconductor; forming a substrate product having a laser structure, an anode electrode, and a cathode electrode, where the laser structure includes a substrate and a semiconductor region, and the semiconductor region is 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: February 6, 2012
    Publication date: July 19, 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
  • Publication number: 20120142130
    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: June 7, 2012
    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: 20120128016
    Abstract: Provided is a III-nitride semiconductor laser diode which is capable of lasing at a low threshold. A support base has a semipolar or nonpolar primary surface. The c-axis Cx of a III-nitride is inclined relative to the primary surface. An n-type cladding region and a p-type cladding region are provided above the primary surface of the support base. A core semiconductor region is provided between the n-type cladding region and the p-type cladding region. The core semiconductor region includes a first optical guide layer, an active layer, and a second optical guide layer. The active layer is provided between the first optical guide layer and the second optical guide layer. The thickness of the core semiconductor region is not less than 0.5 ?m. This structure allows the confinement of light into the core semiconductor region without leakage of light into the support base, and therefore enables reduction in threshold current.
    Type: Application
    Filed: December 16, 2011
    Publication date: May 24, 2012
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Masahiro ADACHI, Shinji TOKUYAMA, Yohei ENYA, Takashi KYONO, Yusuke YOSHIZUMI, Katsushi AKITA, Masaki UENO, Koji KATAYAMA, Takatoshi IKEGAMI, Takao NAKAMURA
  • Publication number: 20120088326
    Abstract: A method of fabricating a group-III nitride semiconductor laser device includes: preparing a substrate of a hexagonal group-III nitride semiconductor, where the substrate has a semipolar primary surface; forming a substrate product having a laser structure, an anode electrode and a cathode electrode, where the laser structure includes the substrate and a semiconductor region, and where the semiconductor region is formed on the semipolar primary surface; scribing a first surface of the substrate product in part in a direction of the a-axis of the hexagonal group-III nitride semiconductor; 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: Application
    Filed: October 20, 2011
    Publication date: April 12, 2012
    Applicant: 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
  • Publication number: 20120058583
    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. 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 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: Application
    Filed: September 22, 2011
    Publication date: March 8, 2012
    Applicant: 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
  • Publication number: 20110310072
    Abstract: A display part (1) for detecting an external input by means of a photo sensor (8) includes an active matrix substrate (4) including the photo sensor (8), an opposite substrate (6) facing the active matrix substrate (4), a liquid crystal layer (5) interposed between the active matrix substrate (4) and the opposite substrate (6), and a protective plate (3) that covers the surface of the opposite substrate (6) on the side opposite to the surface thereof adjacent to the liquid crystal layer (5). A non-flat portion (7) is formed on the protective plate (3) in a region that is a part of the surface on the side opposite to the surface contacting with the opposite substrate (6) and that faces the photo sensor (8), whereby a position on which contact is made from outside can be recognized more clearly.
    Type: Application
    Filed: October 16, 2009
    Publication date: December 22, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Kei Oyobe, Masahiro Adachi
  • Publication number: 20110291673
    Abstract: Provided is a chemical sensor requiring no ion-sensitive film. Specifically provided is a chemical sensor (1) for detecting a sample base material (19) to be detected in a sample, the chemical sensor (1) including: a sensor TFT (7) of sensor TFTs (7) each of which has a glass substrate (8) and, on the glass substrate (8), a gate electrode (10), a gate oxide film (11), a silicon layer (12), a source electrode (14), and a drain electrode (15), the silicon layer (12) having a channel region (18) at an opening portion between the source electrode (14) and the drain electrode (15); and extracting signal lines PAS1 to PASn and a sensor signal amplifying and extracting circuit (24) that extract a leak current that is generated in the channel region (18).
    Type: Application
    Filed: February 8, 2010
    Publication date: December 1, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Yoshinori Shibata, Masahiro Adachi
  • Publication number: 20110241016
    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: Application
    Filed: June 18, 2010
    Publication date: October 6, 2011
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Takashi Kyono, Yohei Enya, Yusuke Yoshizumi, Katsushi Akita, Masaki Ueno, Takamichi Sumitomo, Masahiro Adachi, Shinji Tokuyama
  • Publication number: 20110228804
    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 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: Application
    Filed: July 14, 2010
    Publication date: September 22, 2011
    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: 20110221707
    Abstract: A plurality of pixel circuits are provided on a TFT-side substrate 11, light blocking layers 15 and light blocking layer openings 16 are provided between the pixel circuits, and optical sensors 17 are arranged at positions where the light blocking layers 15 are provided. Light blocking layers 18 are also provided at opposing portions of the opposite substrate 12, and light reflecting units 19 are provided correspondingly to the optical sensors 17. In the normal state, backlight BL that has passed through the TFT-side substrate 11 is reflected by the light reflecting unit 19 and falls on the optical sensor 17. When the front surface of the liquid crystal panel is pressed, the two substrates come close to each other, the light reflection direction in the light reflecting unit 19 changes, and the intensity of light detected by the optical sensor 17 changes.
    Type: Application
    Filed: June 25, 2009
    Publication date: September 15, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Kei Oyobe, Masahiro Adachi
  • Publication number: 20110175201
    Abstract: A Group III nitride semiconductor device has a semiconductor region, a metal electrode, and a transition layer. The semiconductor region has a surface comprised of a Group III nitride crystal. The semiconductor region is doped with a p-type dopant. The surface is one of a semipolar surface and a nonpolar surface. The metal electrode is provided on the surface. The transition layer is formed between the Group III nitride crystal of the semiconductor region and the metal electrode. The transition layer is made by interdiffusion of a metal of the metal electrode and a Group III nitride of the semiconductor region.
    Type: Application
    Filed: July 13, 2010
    Publication date: July 21, 2011
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shinji Tokuyama, Masaki Ueno, Masahiro Adachi, Takashi Kyono, Takamichi Sumitomo, Koji Katayama, Yoshihiro Saito
  • Publication number: 20110175103
    Abstract: A semiconductor device has a satisfactory ohmic contact on a p-type principal surface tilting from a c-plane. The principal surface 13a of a p-type semiconductor region 13 extends along a plane tilting from a c-axis (axis <0001>) of hexagonal group-III nitride. A metal layer 15 is deposited on the principal surface 13a of the p-type semiconductor region 13. The metal layer 15 and the p-type semiconductor region 13 are separated by an interface 17 such that the metal layer functions as a non-alloy electrode. Since the hexagonal group-III nitride contains gallium as a group-III element, the principal surface 13a comprising the hexagonal group-III nitride is more susceptible to oxidation compared to the c-plane of the hexagonal group-III nitride. The interface 17 avoids an increase in amount of oxide after the formation of the metal layer 15 for the electrode.
    Type: Application
    Filed: July 14, 2010
    Publication date: July 21, 2011
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shinji TOKUYAMA, Masahiro ADACHI, Takashi KYONO, Yoshihiro SAITO
  • Publication number: 20110164637
    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: Application
    Filed: March 17, 2011
    Publication date: July 7, 2011
    Applicant: 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
  • Publication number: 20110158277
    Abstract: A III-nitride semiconductor laser device is provided with a laser structure and an electrode. The laser structure includes a support base which comprises a hexagonal III-nitride semiconductor and has 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. The laser structure includes first and second fractured faces intersecting with an m-n plane defined by the m-axis of the hexagonal III-nitride semiconductor and an axis normal to the semipolar primary surface. A laser cavity of the III-nitride semiconductor laser device includes the first and second fractured faces.
    Type: Application
    Filed: July 16, 2010
    Publication date: June 30, 2011
    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: 7960918
    Abstract: An electronic device, and a corresponding light emission control method for the electronic device, emit light by utilizing recombination of electrons and holes the device and method input a pulse-shaped driving signal having a duty ratio higher than or equal to 0.7 and lower than 1.0 and thereby causing light to be emitted intermittently. When an electron density is denoted by n, a hole density by p, a thermal velocity of electrons by Vth:n, a thermal velocity of holes by Vth:p, an electron capture cross section of a defect level by ?n, a hole capture cross section of a defect level by ?p, and a pulse width of the driving signal by W, the input driving signal has a pulse width W that satisfies W<1/{n·vth:n·?n·p·vth:p·?p/(n·vth:n·?n+p·vth:p·?p)}.
    Type: Grant
    Filed: February 4, 2008
    Date of Patent: June 14, 2011
    Assignee: Tottori University
    Inventors: Masahiro Adachi, Yutaka Hashimoto, Katsuhisa Kanzaki, Tomoki Abe, Hirofumi Kasada, Koshi Ando
  • Publication number: 20110121265
    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: Application
    Filed: February 26, 2010
    Publication date: May 26, 2011
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Masaki Ueno, Yusuke Yoshizumi, Yohei Enya, Takashi Kyono, Katsushi Akita, Takamichi Sumitomo, Masahiro Adachi, Shinji Tokuyama
  • Publication number: 20110108853
    Abstract: A compound semiconductor device having reduced contact resistance to an electrode is provided. The compound semiconductor device includes an n-substrate 3 comprising a hexagonal compound semiconductor GaN and having surfaces S1 and S2; an n-electrode 13 formed on the surface S1 of the n-substrate 3; a layered product having an n-cladding layer 5, an active layer 7, a p-cladding layer 9, and a contact layer 11 formed on the surface S2 of the n-substrate 3; and a p-electrode 15 formed on the p-cladding layer 9. The number of N atoms contained on the surface S1 of the n-substrate 3 is more than the number of Ga atoms contained on the surface S1. The electrode formed on the surface S1 is an n-electrode 13. The surface S1 has an oxygen concentration of not more than 5 atomic percent. The number of Ga atoms contained on the surface S3 of the contact layer 11 is more than the number of N atoms contained on the surface S3. The electrode formed on the surface S3 is a p-electrode 15.
    Type: Application
    Filed: July 13, 2010
    Publication date: May 12, 2011
    Applicant: Sumitomo Electric Industires, Ltd.
    Inventors: Masahiro ADACHI, Shinji Tokuyama, Koji Katayama
  • Patent number: 7933303
    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: July 27, 2010
    Date of Patent: April 26, 2011
    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
  • Publication number: 20110075694
    Abstract: In a III-nitride semiconductor laser device, a laser structure includes a support base with a semipolar primary surface comprised of a III-nitride semiconductor, and a semiconductor region provided on the semipolar primary surface of the support base. First and second dielectric multilayer films for an optical cavity of the nitride semiconductor laser device are provided on first and second end faces of the semiconductor region, respectively. 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 provided between the first cladding layer and the second cladding layer. The first cladding layer, the second cladding layer, and the active layer are arranged in an axis normal to the semipolar primary surface.
    Type: Application
    Filed: July 7, 2010
    Publication date: March 31, 2011
    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
  • Publication number: 20110075695
    Abstract: In a III-nitride semiconductor laser device, a laser structure includes a support base with a semipolar primary surface comprised of a III-nitride semiconductor, and a semiconductor region provided on the semipolar primary surface of the support base. First and second dielectric multilayer films for an optical cavity of the nitride semiconductor laser device are provided on first and second end faces of the semiconductor region, respectively. 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 provided between the first cladding layer and the second cladding layer. The first cladding layer, the second cladding layer, and the active layer are arranged in an axis normal to the semipolar primary surface.
    Type: Application
    Filed: July 7, 2010
    Publication date: March 31, 2011
    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