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).
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Publication number: 20150212138Abstract: An open-circuit fault in an electric power distribution line is detected using metering devices each having a communication function and each placed on a power consumer's circuit connected to an electric power distribution system, and a location of the open circuit is identified. An electric power distribution facilities management system obtains, from the power distribution system to which are connected consumers each including a sensor provided with a communication function, meter-reading data within each of the sensors having a communication function, via a communication system.Type: ApplicationFiled: July 22, 2013Publication date: July 30, 2015Inventors: Kazutoshi Tsuchiya, Kenichiro Yamane, Masahiro Adachi, Mitsugu Daino
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Publication number: 20150200521Abstract: A nitride semiconductor light emitting element includes a support base and an epitaxial layer. A p-type dopant is added to a p-side cladding layer of the epitaxial layer, to which a p-side electrode is bonded. The p-type dopant is Mg. An X-ray absorption fine structure spectrum of the p-side cladding layer includes a peak P1 and a peak P2. The peak P1 is a first peak on the high energy side from a K absorption edge of incident X-rays, and the peak P2 is next to the peak P1 on the high energy side and is a second peak on the high energy side from the K absorption edge of the incidence X-rays. A ratio of a value of the peak P1 to a value of the peak P2 is in a range of 70[%] or more and 200[%] or less.Type: ApplicationFiled: March 26, 2014Publication date: July 16, 2015Inventors: Masahiro Adachi, Takumi Yonemura
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Publication number: 20150050768Abstract: A laser diode device includes: a semiconductor substrate including a semi-polar surface, the semiconductor substrate being formed of a hexagonal III-nitride semiconductor; an epitaxial layer including a light emitting layer, the epitaxial layer being formed on the semi-polar surface of the semiconductor substrate, and the epitaxial layer including a ridge section; a first electrode formed on a top surface of the ridge section; an insulating layer covering the epitaxial layer in an adjacent region of the ridge section and a side surface of the ridge section, the insulating layer covering part or all of side surfaces of the first electrode continuously from the epitaxial layer; a pad electrode formed to cover a top surface of the first electrode and the insulating layer, the pad electrode being electrically connected to the first electrode; and a second electrode formed on a surface, of the semiconductor substrate, opposite to the semi-polar surface.Type: ApplicationFiled: September 26, 2014Publication date: February 19, 2015Inventors: Noriyuki FUTAGAWA, Hiroshi NAKAJIMA, Katsunori YANASHIMA, Takashi KYONO, Masahiro ADACHI
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Patent number: 8927962Abstract: 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: GrantFiled: February 26, 2010Date of Patent: January 6, 2015Assignee: Sumitomo Electric Industries, Ltd.Inventors: Masaki Ueno, Yusuke Yoshizumi, Yohei Enya, Takashi Kyono, Katsushi Akita, Takamichi Sumitomo, Masahiro Adachi, Shinji Tokuyama
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Patent number: 8917750Abstract: 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: GrantFiled: December 16, 2011Date of Patent: December 23, 2014Assignee: 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
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Patent number: 8891568Abstract: A laser diode device includes: a semiconductor substrate including a semi-polar surface, the semiconductor substrate being formed of a hexagonal III-nitride semiconductor; an epitaxial layer including a light emitting layer, the epitaxial layer being formed on the semi-polar surface of the semiconductor substrate, and the epitaxial layer including a ridge section; a first electrode formed on a top surface of the ridge section; an insulating layer covering the epitaxial layer in an adjacent region of the ridge section and a side surface of the ridge section, the insulating layer covering part or all of side surfaces of the first electrode continuously from the epitaxial layer; a pad electrode formed to cover a top surface of the first electrode and the insulating layer, the pad electrode being electrically connected to the first electrode; and a second electrode formed on a surface, of the semiconductor substrate, opposite to the semi-polar surface.Type: GrantFiled: December 7, 2012Date of Patent: November 18, 2014Assignees: Sony Corporation, Sumitomo Electric Industries, Inc.Inventors: Noriyuki Futagawa, Hiroshi Nakajima, Katsunori Yanashima, Takashi Kyono, Masahiro Adachi
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Patent number: 8803274Abstract: 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: GrantFiled: June 18, 2010Date of Patent: August 12, 2014Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takashi Kyono, Yohei Enya, Yusuke Yoshizumi, Katsushi Akita, Masaki Ueno, Takamichi Sumitomo, Masahiro Adachi, Shinji Tokuyama
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Publication number: 20140200729Abstract: A power state of any point of a power system is estimated with high accuracy to appropriately perform monitoring of the state of the entire power system. A power system state estimation device is provided which includes a power system data database which holds node information indicative of positions in the power system and facility information including sensors in association with each other, a sensor data database which holds the output of the sensors, an estimation environment setting unit which determines a sensor to be used when a power state at a particular node is estimated, using the information of the power system data database, and a state estimation unit which in correspondence to the sensor used at the particular node determined by the estimation environment setting unit, obtains the output of the sensor from the sensor data database and performs state estimation for the entire power system.Type: ApplicationFiled: August 7, 2012Publication date: July 17, 2014Applicants: THE KANSAI ELECTRIC POWER CO., INC., HITACHI, LTD.Inventors: Kenichiro Yamane, Masahiro Watanabe, Masahiro Adachi, Masahiro Minami, Yasuo Matsuura, Tomohiko Morita
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Patent number: 8741674Abstract: 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: GrantFiled: December 22, 2011Date of Patent: June 3, 2014Assignee: 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
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Patent number: 8693515Abstract: 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: GrantFiled: March 17, 2011Date of Patent: April 8, 2014Assignee: 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
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Patent number: 8653621Abstract: 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: GrantFiled: June 18, 2010Date of Patent: February 18, 2014Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takashi Kyono, Yohei Enya, Yusuke Yoshizumi, Katsushi Akita, Masaki Ueno, Takamichi Sumitomo, Masahiro Adachi, Shinji Tokuyama
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Patent number: 8619828Abstract: 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: GrantFiled: July 14, 2010Date of Patent: December 31, 2013Assignee: Sumitomo Electronic Industries, Ltd.Inventors: Katsushi Akita, Yohei Enya, Takashi Kyono, Masahiro Adachi, Shinji Tokuyama, Yusuke Yoshizumi, Takamichi Sumitomo, Masaki Ueno
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Patent number: 8581296Abstract: 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: GrantFiled: July 13, 2010Date of Patent: November 12, 2013Assignee: Sumitomo Electric Industries, Ltd.Inventors: Masahiro Adachi, Shinji Tokuyama, Koji Katayama
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Publication number: 20130295704Abstract: 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: ApplicationFiled: December 22, 2011Publication date: November 7, 2013Applicant: 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
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Patent number: 8546163Abstract: 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: GrantFiled: September 22, 2011Date of Patent: October 1, 2013Assignee: 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
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Patent number: 8541253Abstract: 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: GrantFiled: March 9, 2012Date of Patent: September 24, 2013Assignee: 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
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Patent number: 8507305Abstract: 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: GrantFiled: April 10, 2012Date of Patent: August 13, 2013Assignee: 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
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Patent number: 8415707Abstract: 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: GrantFiled: July 13, 2010Date of Patent: April 9, 2013Assignee: Sumitomo Electric Industries, Ltd.Inventors: Shinji Tokuyama, Masaki Ueno, Masahiro Adachi, Takashi Kyono, Takamichi Sumitomo, Koji Katayama, Yoshihiro Saito
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Publication number: 20130051417Abstract: 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: ApplicationFiled: April 23, 2012Publication date: February 28, 2013Applicants: SONY CORPORATION, SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Takamichi SUMITOMO, Takashi KYONO, Masaki UENO, Yusuke YOSHIZUMI, Yohei ENYA, Masahiro ADACHI, Shimpei TAKAGI, Katsunori YANASHIMA
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Publication number: 20130051418Abstract: 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: ApplicationFiled: July 24, 2012Publication date: February 28, 2013Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Takamichi SUMITOMO, Masaki UENO, Yusuke YOSHIZUMI, Takahisa YOSHIDA, Masahiro ADACHI