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: 20080067541
    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: October 30, 2007
    Publication date: March 20, 2008
    Inventors: Tadao Toda, Tsutomu Yamaguchi, Masayuki Hata, Yasuhiko Nomura
  • Publication number: 20080069162
    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: October 30, 2007
    Publication date: March 20, 2008
    Inventors: Tadao Toda, Tsutomu Yamaguchi, Masayuki Hata, Yasuhiko Nomura
  • Publication number: 20070292979
    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: March 20, 2007
    Publication date: December 20, 2007
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Masayuki Hata, Tadao Toda, Shigeyuki Okamoto, Daijiro Inoue, Yasuyuki Bessho, Yasuhiko Nomura, Tsutomu Yamaguchi
  • Publication number: 20070235750
    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: June 4, 2007
    Publication date: October 11, 2007
    Inventors: Tadao Toda, Tsutomu Yamaguchi, Masayuki Hata, Yasuhiko Nomura
  • Publication number: 20070221932
    Abstract: A method of fabricating a nitride-based semiconductor light-emitting device capable of suppressing reduction of characteristics and a yield is obtained. This method of fabricating a nitride-based semiconductor light-emitting device comprises steps of forming a groove portion on a nitride-based semiconductor substrate by selectively removing a prescribed region of a second region of the nitride-based semiconductor substrate other than a first region corresponding to a light-emitting portion of a nitride-based semiconductor layer up to a prescribed depth and forming the nitride-based semiconductor layer having a different composition from the nitride-based semiconductor substrate on the first region and the groove portion of the nitride-based semiconductor substrate.
    Type: Application
    Filed: September 20, 2006
    Publication date: September 27, 2007
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Takashi Kano, Masayuki Hata, Yasuhiko Nomura
  • Publication number: 20070223548
    Abstract: In a semiconductor laser device including a package for airtight sealing, and a semiconductor laser element provided in the package, a moisture concentration inside the package is 2500 ppm or less and arithmetic mean roughness in at least one portion of an inner surface of the package is 0.3 ?m or less.
    Type: Application
    Filed: March 21, 2007
    Publication date: September 27, 2007
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Hiroki Ohbo, Yasuyuki Bessho, Kazushi Mori, Yasuhiko Nomura
  • Publication number: 20070170442
    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: Application
    Filed: March 22, 2007
    Publication date: July 26, 2007
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Masayuki Hata, Yasuhiko Nomura, Daijiro Inoue
  • Publication number: 20070147448
    Abstract: A nitride semiconductor laser device 20 has nitride semiconductor laser element 5 with dielectric layer 5b composed of AlN formed on light emitting face 5a. The nitride semiconductor laser element 5 is air-tightly sealed within package 1. The atmosphere within the package contains nitrogen with less than 5000 ppm water and more than 5% nitrogen. By controlling the atmosphere within package 1, less deterioration of output and less deterioration of reliability is achieved due to changes in the dielectric layer, which is composed of nitride formed at a facet of the semiconductor laser.
    Type: Application
    Filed: December 21, 2006
    Publication date: June 28, 2007
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Yasuyuki Bessho, Yasuhiko Nomura
  • Publication number: 20070147449
    Abstract: A nitride semiconductor laser device 20 has nitride semiconductor laser element 5 with dielectric layer 5b composed of SiO2 formed on light emitting face 5a. The nitride semiconductor laser element 5 is air-tightly sealed within package 1. The atmosphere within the package contains oxygen with less than 5000 ppm water and more than 5% oxygen. By controlling the atmosphere within package 1, less deterioration of outputs and less deterioration of reliability is achieved due to changes in the dielectric layer formed at a facet of the semiconductor laser.
    Type: Application
    Filed: December 21, 2006
    Publication date: June 28, 2007
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Yasuyuki Bessho, Yasuhiko Nomura
  • Patent number: 7209505
    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: September 14, 2006
    Date of Patent: April 24, 2007
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masayuki Hata, Yasuhiko Nomura, Daijiro Inoue
  • Publication number: 20070077669
    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: December 4, 2006
    Publication date: April 5, 2007
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Tadao Toda, Tsutomu Yamaguchi, Masayuki Hata, Yasuhiko Nomura
  • Publication number: 20070057337
    Abstract: A semiconductor device includes a semiconductor substrate formed of at least two kinds of group III elements and nitrogen, an active layer formed on the semiconductor substrate, and a nitride semiconductor layer formed on a surface of the semiconductor substrate and formed between the semiconductor substrate and the active layer. The nitride semiconductor layer is formed of the same constituent elements of the semiconductor substrate. A composition ratio of the lightest element among the group III elements of the nitride semiconductor layer is higher than a composition ratio of the corresponding element of the semiconductor substrate.
    Type: Application
    Filed: September 11, 2006
    Publication date: March 15, 2007
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Takashi Kano, Masayuki Hata, Yasuhiko Nomura
  • Publication number: 20070012929
    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: Application
    Filed: September 14, 2006
    Publication date: January 18, 2007
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Masayuki Hata, Yasuhiko Nomura, Daijiro Inoue
  • Publication number: 20060251138
    Abstract: A blue-violet emission point, an infrared emission point, and a red emission point in a semiconductor laser apparatus are arranged so as to be arranged in this order on a substantially straight line along a first direction. A blue-violet laser beam emitted from the blue-violet emission point and a red laser beam emitted from the red emission point are incident on an optical disk by an optical system comprising a polarizing beam splitter, a collimator lens, a beam expander, a ?/4 plate, an objective lens, a cylindrical lens, and an optical disk, is returned from the optical disk, and is introduced into an photodetector. The infrared laser beam emitted from the infrared emission point is incident on the optical disk by the optical system, is returned from the optical disk, and is introduced into the photodetector.
    Type: Application
    Filed: March 23, 2006
    Publication date: November 9, 2006
    Inventors: Masayuki Hata, Yasuyuki Bessho, Yasuhiko Nomura, Masayuki Shono, Seiji Kajiyama, Yoichi Tsuchiya
  • Publication number: 20060227838
    Abstract: A monolithic red/infrared semiconductor laser device is joined to a blue-violet semiconductor laser device. The distance between a blue-violet emission point in the blue-violet semiconductor laser device and an infrared emission point in an infrared semiconductor laser device is significantly shorter than the distance between a red emission point in a red semiconductor laser device and the infrared emission point. A blue-violet laser beam, a red laser beam, and an infrared laser beam respectively emitted from the blue-violet emission point, the red emission point, and the infrared emission point are introduced into a photodetector after being incident on an optical disk by an optical system comprising a polarizing beam splitter, a collimator lens, a beam expander, a ?/4 plate, an objective lens, a cylindrical lens, and an optical axis correction element.
    Type: Application
    Filed: March 28, 2006
    Publication date: October 12, 2006
    Inventors: Masayuki Hata, Yasuyuki Bessho, Yasuhiko Nomura, Masayuki Shono, Kenji Nagatomi, Yoichi Tsuchiya
  • Publication number: 20060222036
    Abstract: A semiconductor laser device capable of reducing the threshold current and improving luminous efficiency and a method of fabricating the same are obtained. This semiconductor laser device comprises a semiconductor substrate having a principal surface and a semiconductor element layer, formed on the principal surface of the semiconductor substrate, having a principal surface substantially inclined with respect to the principal surface of the semiconductor substrate and including an emission layer.
    Type: Application
    Filed: March 31, 2006
    Publication date: October 5, 2006
    Inventors: Tsutomu Yamaguchi, Masayuki Hata, Takashi Kano, Masayuki Shono, Hiroki Ohbo, Yasuhiko Nomura, Hiroaki Izu
  • Patent number: 7116693
    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: September 23, 2005
    Date of Patent: October 3, 2006
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masayuki Hata, Yasuhiko Nomura, Daijiro Inoue
  • Patent number: 7088755
    Abstract: A nitride-based semiconductor laser device capable of attaining stabilization of a laser beam and inhibiting a threshold current and an operating current from increase is provided. This nitride-based semiconductor laser device comprises a substrate consisting of either a nitride-based semiconductor doped with an impurity or a boride-based material, an n-type cladding layer formed on the substrate, an active layer consisting of a nitride-based semiconductor formed on the n-type cladding layer, a p-type cladding layer formed on the active layer and a light guide layer formed only between the active layer and the p-type cladding layer in the interspaces between the active layer and the n- and p-type cladding layers.
    Type: Grant
    Filed: September 17, 2003
    Date of Patent: August 8, 2006
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yasuhiko Nomura, Daijiro Inoue, Masayuki Hata, Takashi Kano
  • Publication number: 20060045156
    Abstract: A one-chip semiconductor laser device for use in a semiconductor laser apparatus has a structure in which a red semiconductor laser device and an infrared semiconductor laser device are stacked on a blue-violet semiconductor laser device. The blue-violet semiconductor laser device is manufactured by forming semiconductor layers on a GaN substrate. Each of the red semiconductor laser device and the infrared semiconductor laser device is manufactured by forming semiconductor layers on a GaAs substrate. The modulus of elasticity of GaAs is smaller than the modulus of elasticity of GaN. The length of each of the red semiconductor laser device and the infrared semiconductor laser device is longer than the length of the blue-violet semiconductor laser device.
    Type: Application
    Filed: August 31, 2005
    Publication date: March 2, 2006
    Inventors: Masayuki Hata, Yasuyuki Bessho, Yasuhiko Nomura, Masayuki Shono
  • Publication number: 20060018353
    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: Application
    Filed: September 23, 2005
    Publication date: January 26, 2006
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Masayuki Hata, Yasuhiko Nomura, Daijiro Inoue