Patents by Inventor Yasuhiko Nomura

Yasuhiko Nomura 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: 20060011946
    Abstract: A nitride semiconductor laser element capable of controlling the lateral confinement of light with a good reproducibility, the nitride semiconductor element comprising an n-type cladding layer (3), an MQW light emitting layer (4) formed on the cladding layer (3), a p-type cladding layer (5) and a p-type contact layer (6) formed on the light emitting layer (4), and an ion implantation light absorbing layer (7) formed, by introducing carbon, in regions other than a current passing region (8) in the cladding layer (5) and the contact layer (6).
    Type: Application
    Filed: February 28, 2003
    Publication date: January 19, 2006
    Inventors: Tadao Toda, Tsutomu Yamaguchi, Masayuki Hata, Yasuhiko Nomura, Masayuki Shouno, Yuuji Hishida, Keiichi Yodoshi, Daijiro Inoue, Takashi Kano, Nobuhiko Hayashi
  • Patent number: 6977953
    Abstract: A nitride-based semiconductor light-emitting device capable of stabilizing transverse light confinement is obtained. This nitride-based semiconductor light-emitting device comprises an emission layer, a cladding layer, formed on the emission layer, including a first nitride-based semiconductor layer and having a current path portion and a current blocking layer, formed to cover the side surfaces of the current path portion, including a second nitride-based semiconductor layer, while the current blocking layer is formed in the vicinity of the current path portion and a region having no current blocking layer is included in a region not in the vicinity of the current path portion. Thus, the width of the current blocking layer is reduced, whereby strain applied to the current blocking layer is relaxed. Consequently, the thickness of the current blocking layer can be increased, thereby stabilizing transverse light confinement.
    Type: Grant
    Filed: July 24, 2002
    Date of Patent: December 20, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masayuki Hata, Yasuhiko Nomura, Daijiro Inoue
  • Patent number: 6967985
    Abstract: A surface emission semiconductor laser device capable of substantially completely controlling the plane of polarization is obtained. This surface emission semiconductor laser device comprises a first multi-layer reflector, an emission layer formed on the first multi-layer reflector and a second multi-layer reflector formed on the emission layer, and at least either the first multi-layer reflector or the second multi-layer reflector includes a striped part worked in a striped manner in a prescribed period.
    Type: Grant
    Filed: February 11, 2003
    Date of Patent: November 22, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Koji Tominaga, Kazushi Mori, Atsushi Tajiri, Yasuhiko Nomura, Ryoji Hiroyama
  • Publication number: 20050232327
    Abstract: Improving the lifetime of an integrated semiconductor laser diode module into which a GaN semiconductor laser diode and a GaP semiconductor laser diode are integrated, and the lasing properties of the laser diodes. Prior to a joining step of an LD 1 wafer that is made of a nitride semiconductor structure formed on a GaN substrate and an LD 2 wafer that is made of an aluminum gallium indium phosphide semiconductor structure, a facet of a resonator of the nitride semiconductor structure is formed by etching A facet of a resonator of the aluminum gallium indium phosphide semiconductor structure is formed, after the joining step, by cleaving. The wafers are joined so that the facets of the resonators of the nitride semiconductor structure and aluminum gallium indium phosphide semiconductor structure are out of alignment in a lengthwise direction of the resonators.
    Type: Application
    Filed: February 28, 2005
    Publication date: October 20, 2005
    Inventors: Yasuhiko Nomura, Yasuyuki Bessho, Masayuki Hata, Tsutomu Yamaguchi
  • Publication number: 20050232321
    Abstract: A semiconductor laser apparatus comprises a first semiconductor laser device that emits a blue-violet laser beam, a second semiconductor laser device that emits a red laser beam, and a conductive package body. The first semiconductor laser device has a p-side pad electrode and an n-side electrode. The p-side pad electrode and n-side electrode of the first semiconductor laser device are electrically isolated from the package body. The p-side pad electrode of the first semiconductor laser device is connected with a drive circuit that generates a positive potential, while the n-side electrode thereof is connected with a dc power supply that generates a negative potential.
    Type: Application
    Filed: March 14, 2005
    Publication date: October 20, 2005
    Inventors: Daijiro Inoue, Yasuyuki Bessho, Masayuki Hata, Yasuhiko Nomura
  • Patent number: 6956884
    Abstract: A second cladding layer composed of p-AlGaN and a second contact layer composed of p-GaN are formed in this order on a light emitting layer composed of a nitride based semiconductor. A predetermined region of the second cladding layer and the second contact layer is removed, to form a ridge portion. A high-resistive current blocking layer, to which impurities have been added, is formed on an upper surface of a flat portion of the second cladding layer, which remains without being removed, and on both sidewalls of the ridge portion.
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: October 18, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yasuhiko Nomura, Nobuhiko Hayashi, Masayuki Shono
  • Publication number: 20050224835
    Abstract: A nitride-based semiconductor laser device capable of elongating the life thereof is obtained. This nitride-based semiconductor laser device comprises a first cladding layer consisting of a first conductivity type nitride-based semiconductor, an emission layer, formed on the first cladding layer, consisting of a nitride-based semiconductor and a second cladding layer, formed on the emission layer, consisting of a second conductivity type nitride-based semiconductor, while the emission layer includes an active layer emitting light, a light guiding layer for confining light and a carrier blocking layer, arranged between the active layer and the light guiding layer, having a larger band gap than the light guiding layer.
    Type: Application
    Filed: June 8, 2005
    Publication date: October 13, 2005
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Yasuhiko Nomura, Takashi Kano
  • Patent number: 6954478
    Abstract: A nitride-based semiconductor laser device capable of elongating the life thereof is obtained. This nitride-based semiconductor laser device comprises a first cladding layer consisting of a first conductivity type nitride-based semiconductor, an emission layer, formed on the first cladding layer, consisting of a nitride-based semiconductor and a second cladding layer, formed on the emission layer, consisting of a second conductivity type nitride-based semiconductor, while the emission layer includes an active layer emitting light, a light guiding layer for confining light and a carrier blocking layer, arranged between the active layer and the light guiding layer, having a larger band gap than the light guiding layer.
    Type: Grant
    Filed: February 3, 2003
    Date of Patent: October 11, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yasuhiko Nomura, Takashi Kano
  • Publication number: 20050221590
    Abstract: Provided is a manufacturing method of a nitride semiconductor device having a nitride semiconductor substrate (e.g. GaN substrate) in which dislocation concentrated regions align in stripe formation, the dislocation concentrated regions extending from a front surface to a back surface of the substrate, the manufacturing method being for stacking each of a plurality of nitride semiconductor layers on the front surface of the substrate in a constant film thickness. Grooves are formed on the nitride semiconductor substrate in the immediate areas of dislocation concentrated regions. Each of the nitride semiconductor layers is formed as a crystal growth layer on the main surface of the nitride semiconductor substrate to which the grooves have been formed.
    Type: Application
    Filed: March 16, 2005
    Publication date: October 6, 2005
    Inventors: Takashi Kano, Tsutomu Yamaguchi, Hiroaki Izu, Masayuki Hata, Yasuhiko Nomura
  • Publication number: 20050191775
    Abstract: A method of fabricating a nitride-based semiconductor device capable of reducing contact resistance between a nitrogen face of a nitride-based semiconductor substrate or the like and an electrode is provided. This method of fabricating a nitride-based semiconductor device comprises steps of etching the back surface of a first semiconductor layer consisting of either an n-type nitride-based semiconductor layer or a nitride-based semiconductor substrate having a wurtzite structure and thereafter forming an n-side electrode on the etched back surface of the first semiconductor layer.
    Type: Application
    Filed: April 26, 2005
    Publication date: September 1, 2005
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Tadao Toda, Tsutomu Yamaguchi, Masayuki Hata, Yasuhiko Nomura
  • Patent number: 6928096
    Abstract: A nitride-based semiconductor laser device capable of preventing deterioration in the vicinity of a facet is obtained. This nitride-based semiconductor laser device comprises a first conductivity type first cladding layer consisting of a nitride-based semiconductor formed on a substrate, an active layer formed on the first cladding layer, a second conductivity type second cladding layer consisting of a nitride-based semiconductor formed on the active layer and a high-resistance region formed at least portions of the active layer and the second cladding layer in the vicinity of the facet. The high-resistance region has higher resistance than the remaining regions, whereby a current hardly flows to the high-resistance region. Thus, temperature increase is suppressed in the vicinity of the facet, whereby deterioration can be prevented in the vicinity of the facet.
    Type: Grant
    Filed: April 3, 2002
    Date of Patent: August 9, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yasuhiko Nomura, Tatsuya Kunisato
  • Patent number: 6914922
    Abstract: A semiconductor laser device is constructed by stacking a buffer layer, an undoped GaN layer, an n-GaN contact layer, an n-InGaN crack preventing layer, an n-AlGaN cladding layer, a light emitting layer, a p-AlGaN cladding layer, and a p-GaN contact layer in this order. A ridge portion comprising the p-GaN contact layer and the p-AlGaN cladding layer is formed, and the thickness of the p-AlGaN cladding layer in the ridge portion is less than 0.3 ?m.
    Type: Grant
    Filed: July 5, 2001
    Date of Patent: July 5, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Nobuhiko Hayashi, Takenori Goto, Takashi Kano, Yasuhiko Nomura
  • Patent number: 6891872
    Abstract: A semiconductor laser device is characterized in that an angle ? of inclination formed by the side surfaces of a ridge portion and a lower part of the ridge portion is at least 70° and not more than 117°, a p-type cladding layer is made of AlX1Ga1-X1As, a first current blocking layer is made of AlX2Ga1-X2As, the distance between an emission layer and the first current blocking layer satisfies the relation of t?0.275/(1?(X2?X1)) assuming that t represents the distance, and a lower width W of the ridge portion is at least 2 ?m and not more than 5 ?m.
    Type: Grant
    Filed: September 25, 2000
    Date of Patent: May 10, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Ryouji Hiroyama, Yasuhiko Nomura, Koutarou Furusawa, Kunio Takeuchi, Shigeyuki Okamoto
  • Patent number: 6891871
    Abstract: An SiNx film is formed on partial side surfaces and an electrode forming surface excluding an n-side electrode of a first contact layer, the side surfaces of each layer, the upper surface of a second cladding layer and the side surfaces of a ridge portion. An SiOy film is formed on the SiNx film. The SiNx film and the SiOy film form a dielectric film.
    Type: Grant
    Filed: September 21, 2000
    Date of Patent: May 10, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yasuhiko Nomura, Nobuhiko Hayashi, Masayuki Hata, Masayuki Shono
  • Patent number: 6890779
    Abstract: A method of fabricating a nitride-based semiconductor device capable of reducing contact resistance between a nitrogen face of a nitride-based semiconductor substrate or the like and an electrode is provided. This method of fabricating a nitride-based semiconductor device comprises steps of etching the back surface of a first semiconductor layer consisting of either an n-type nitride-based semiconductor layer or a nitride-based semiconductor substrate having a wurtzite structure and thereafter forming an n-side electrode on the etched back surface of the first semiconductor layer.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: May 10, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tadao Toda, Tsutomu Yamaguchi, Masayuki Hata, Yasuhiko Nomura
  • Publication number: 20050029539
    Abstract: A method of fabricating a nitride-based semiconductor device capable of reducing contact resistance between a nitrogen face of a nitride-based semiconductor substrate or the like and an electrode is provided. This method of fabricating a nitride-based semiconductor device comprises steps of etching the back surface of a first semiconductor layer consisting of either an n-type nitride-based semiconductor layer or a nitride-based semiconductor substrate having a wurtzite structure and thereafter forming an n-side electrode on the etched back surface of the first semiconductor layer.
    Type: Application
    Filed: September 9, 2004
    Publication date: February 10, 2005
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Tadao Toda, Tsutomu Yamaguchi, Masayuki Hata, Yasuhiko Nomura
  • Publication number: 20040245540
    Abstract: A semiconductor device capable of stabilizing operations thereof is provided. This semiconductor device comprises a substrate provided with a region having concentrated dislocations at least on part of the back surface thereof, a semiconductor element layer formed on the front surface of the substrate, an insulator film formed on the region of the back surface of the substrate having concentrated dislocations and a back electrode formed to be in contact with a region of the back surface of the substrate other than the region having concentrated dislocations.
    Type: Application
    Filed: January 29, 2004
    Publication date: December 9, 2004
    Inventors: Masayuki Hata, Tadao Toda, Shigeyuki Okamoto, Daijiro Inoue, Yasuyuki Bessho, Yasuhiko Nomura, Tsutomu Yamaguchi
  • Patent number: 6791120
    Abstract: A method of fabricating a nitride-based semiconductor device capable of reducing contact resistance between a nitrogen face of a nitride-based semiconductor substrate or the like and an electrode is provided. This method of fabricating a nitride-based semiconductor device comprises steps of etching the back surface of a first semiconductor layer consisting of either an n-type nitride-based semiconductor layer or a nitride-based semiconductor substrate having a wurtzite structure and thereafter forming an n-side electrode on the etched back surface of the first semiconductor layer.
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: September 14, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tadao Toda, Tsutomu Yamaguchi, Masayuki Hata, Yasuhiko Nomura
  • Patent number: 6778575
    Abstract: A semiconductor laser device having a real refractive index guided structure capable of obtaining a high kink light output and a high maximum light output also when a vertical beam divergence angle is at a small level of at least 12.5° and not more than 20.0° is provided. This semiconductor laser device comprises an n-type cladding layer of AlGaInP formed on an n-type GaAs substrate, an active layer having an AlGaInP layer formed on the n-type cladding layer, a p-type cladding layer of AlGaInP formed on the active layer and a light confinement layer formed to partially cover the p-type cladding layer, and a vertical beam divergence angle is at least 12.5° and not more than 20.0°. Thus, a higher kink light output and a higher maximum light output can be obtained as compared with a conventional semiconductor laser device having a vertical beam divergence angle exceeding 20.0°.
    Type: Grant
    Filed: March 20, 2002
    Date of Patent: August 17, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Ryoji Hiroyama, Daijiro Inoue, Yasuhiko Nomura, Kunio Takeuchi
  • Patent number: 6771676
    Abstract: A semiconductor laser device capable of improving reliability is obtained in a structure formed by mounting a semiconductor laser element on a submount (base) in a junction-down system. This semiconductor laser device comprises a first electrode layer formed on the surface of a semiconductor element including an emission layer to have a shape comprising recess portions and projection portions, a base mounted with the semiconductor element, and a plurality of low melting point metal layers provided between the first electrode layer formed on the surface of the semiconductor element and the base for bonding the first electrode layer formed on the surface of the semiconductor element and the base to each other. Thus, the plurality of low melting point metal layers easily embed clearances resulting from the shape comprising recess portions and projection portions of the surface of the semiconductor element dissimilarly to a case of employing a single low melting point metal layer.
    Type: Grant
    Filed: September 5, 2002
    Date of Patent: August 3, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Kunio Takeuchi, Shigeyuki Okamoto, Ryoji Hiroyama, Yasuhiko Nomura, Daijiro Inoue