Patents by Inventor Munetaka Watanabe

Munetaka Watanabe 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).

  • Patent number: 8569735
    Abstract: A semiconductor light-emitting element including a substrate, a laminated semiconductor layer including a light-emitting layer formed over the substrate, one electrode (111) formed over the upper face of the laminated semiconductor layer, and an other electrode formed over the exposed surface of the semiconductor layer, from which the laminated semiconductor layer is partially cut off. The one electrode (111) includes a junction layer (110) and a bonding pad electrode (120) formed to cover the junction layer. The bonding pad electrode has a maximum thickness larger than that of the junction layer, and is composed of one or two or more layers. Slopes (110c), (117c) and (119c), which are made gradually thinner toward the outer circumference, are formed in the outer circumference portions (110d) and (120d) of the junction layer and the bonding pad electrode. Also disclosed is a method for manufacturing the element and a lamp.
    Type: Grant
    Filed: June 16, 2009
    Date of Patent: October 29, 2013
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Daisuke Hiraiwa, Takehiko Okabe, Remi Ohba, Munetaka Watanabe
  • Patent number: 8188495
    Abstract: An object of the present invention is to provide a gallium nitride-based compound semiconductor light emitting device having excellent light extraction efficiency and a high emission output in which a planar shape is a rectangular shape with vertical and longitudinal sides each having a different length. The present light emitting device comprises a substrate and a gallium nitride-based compound semiconductor layer formed on the substrate, wherein a planar shape is a rectangular shape with vertical and longitudinal sides each having a different length, and a side surface of the gallium nitride-based compound semiconductor layer is not vertical to a principal surface of the substrate.
    Type: Grant
    Filed: June 8, 2007
    Date of Patent: May 29, 2012
    Assignee: Showa Denko K.K.
    Inventors: Noritaka Muraki, Munetaka Watanabe
  • Patent number: 8115212
    Abstract: An object of the present invention is to provide a transparent positive electrode for use in a face-up-type chip which can emit intense light even using a low drive voltage. The inventive positive electrode for a semiconductor light-emitting device comprises a transparent electrode formed on a semiconductor layer and a bonding pad electrode formed on the transparent electrode, wherein the bonding pad electrode has a reflecting layer that is in contact with at least the transparent electrode.
    Type: Grant
    Filed: July 28, 2005
    Date of Patent: February 14, 2012
    Assignee: Showa Denko K.K.
    Inventors: Hisayuki Miki, Noritaka Muraki, Munetaka Watanabe
  • Patent number: 8049243
    Abstract: This gallium nitride-based compound semiconductor light emitting device includes an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer that are composed of gallium nitride-based compound semiconductors and are deposited in that order on a substrate, and further includes a negative electrode and a positive electrode that are in contact with the n-type semiconductor layer and the p-type semiconductor layer, respectively, wherein the positive electrode has a translucent electrode composed of a three-layer structure including a contact metal layer that contacts at least the p-type semiconductor layer, a current diffusion layer provided on the contact metal layer and having conductivity greater than that of the contact metal layer, and a bonding pad layer provided on the current diffusion layer, and a mixed positive electrode-metal layer including a metal that forms the contact metal layer is present in a positive electrode side surface of the p-type semiconductor layer.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: November 1, 2011
    Assignee: Showa Denko K.K.
    Inventors: Koji Kamei, Munetaka Watanabe, Noritaka Muraki, Yasushi Ohno
  • Publication number: 20110089401
    Abstract: A semiconductor light-emitting element including a substrate, a laminated semiconductor layer including a light-emitting layer formed over the substrate, one electrode (111) formed over the upper face of the laminated semiconductor layer, and an other electrode formed over the exposed surface of the semiconductor layer, from which the laminated semiconductor layer is partially cut off. The one electrode (111) includes a junction layer (110) and a bonding pad electrode (120) formed to cover the junction layer. The bonding pad electrode has a maximum thickness larger than that of the junction layer, and is composed of one or two or more layers. Slopes (110c), (117c) and (119c), which are made gradually thinner toward the outer circumference, are formed in the outer circumference portions (110d) and (120d) of the junction layer and the bonding pad electrode. Also disclosed is a method for manufacturing the element and a lamp.
    Type: Application
    Filed: June 16, 2009
    Publication date: April 21, 2011
    Applicant: Showa Denko K.K.
    Inventors: Daisuke Hiraiwa, Takehiko Okabe, Remi Ohba, Munetaka Watanabe
  • Patent number: 7875896
    Abstract: An object of the present invention is to provide a positive electrode having high transparency, low contact resistance and excellent current diffusibility and not requiring electron beam irradiation, high-temperature annealing or heat treatment, for alloying, in an oxygen atmosphere. The inventive transparent positive electrode for gallium nitride-based compound semiconductor light-emitting devices comprises a contact metal layer in contact with a p-type semiconductor layer, a current diffusing layer on the contact metal layer, the current diffusing layer having an electrical conductivity larger than that of the contact metal layer, and a bonding pad layer on the current diffusing layer.
    Type: Grant
    Filed: April 28, 2005
    Date of Patent: January 25, 2011
    Assignee: Showa Denko K.K.
    Inventors: Munetaka Watanabe, Noritaka Muraki, Koji Kamei, Yasushi Ohno
  • Publication number: 20090212319
    Abstract: An object of the present invention is to provide a gallium nitride-based compound semiconductor light emitting device having excellent light extraction efficiency and a high emission output in which a planar shape is a rectangular shape with vertical and longitudinal sides each having a different length. The present light emitting device comprises a substrate and a gallium nitride-based compound semiconductor layer formed on the substrate, wherein a planar shape is a rectangular shape with vertical and longitudinal sides each having a different length, and a side surface of the gallium nitride-based compound semiconductor layer is not vertical to a principal surface of the substrate.
    Type: Application
    Filed: June 8, 2007
    Publication date: August 27, 2009
    Applicant: SHOWA DENKO K.K.
    Inventors: Noritaka Muraki, Munetaka Watanabe
  • Publication number: 20090184329
    Abstract: An object of the present invention is to provide a transparent positive electrode for use in a face-up-type chip which can emit intense light even using a low drive voltage. The inventive positive electrode for a semiconductor light-emitting device comprises a transparent electrode formed on a semiconductor layer and a bonding pad electrode formed on the transparent electrode, wherein the bonding pad electrode has a reflecting layer that is in contact with at least the transparent electrode.
    Type: Application
    Filed: July 28, 2005
    Publication date: July 23, 2009
    Applicant: SHOWA DENKO K.K.
    Inventors: Hisayuki Miki, Noritaka Muraki, Munetaka Watanabe
  • Patent number: 7498611
    Abstract: A transparent electrode for a gallium nitride-based compound semiconductor light-emitting device includes a p-type semiconductor layer (5), a contact metal layer (1) formed by ohmic contact on the p-type semiconductor layer, an current diffusion layer (12) formed on the contact metal layer and having a lower magnitude of resistivity on the plane of the transparent electrode than the contact metal, and a bonding pad (13) formed on the current diffusion layer. The transparent electrode is at an advantage in widening the surface of light emission in the p-type semiconductor layer, decreasing the operation voltage in the forward direction, and enabling the bonding pad to provide excellent adhesive strength.
    Type: Grant
    Filed: July 27, 2005
    Date of Patent: March 3, 2009
    Assignee: Showa Denko K.K.
    Inventors: Nobuo Eitoh, Noritaka Muraki, Hisayuki Miki, Munetaka Watanabe
  • Publication number: 20080315237
    Abstract: This gallium nitride-based compound semiconductor light emitting device includes an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer that are composed of gallium nitride-based compound semiconductors and are deposited in that order on a substrate, and further includes a negative electrode and a positive electrode that are in contact with the n-type semiconductor layer and the p-type semiconductor layer, respectively, wherein the positive electrode has a translucent electrode composed of a three-layer structure including a contact metal layer that contacts at least the p-type semiconductor layer, a current diffusion layer provided on the contact metal layer and having conductivity greater than that of the contact metal layer, and a bonding pad layer provided on the current diffusion layer, and a mixed positive electrode-metal layer including a metal that forms the contact metal layer is present in a positive electrode side surface of the p-type semiconductor layer.
    Type: Application
    Filed: May 19, 2005
    Publication date: December 25, 2008
    Inventors: Koji Kamei, Munetaka Watanabe, Noritaka Muraki, Yasushi Ohno
  • Patent number: 7402830
    Abstract: The inventive gallium nitride compound semiconductor light-emitting device comprises a substrate; an n-type semiconductor layer, a light-emitting layer, a p-type semiconductor layer, the layers being successively provided atop the substrate and being formed of a gallium nitride compound semiconductor; a negative electrode provided on the n-type semiconductor layer at a certain portion thereof, the portion being exposed by partial, depthwise removal of the light-emitting layer and the p-type semiconductor layer altogether through reactive ion etching; and a positive electrode provided on the remaining p-type semiconductor layer, wherein the gallium nitride compound semiconductor light-emitting device is produced through reactive ion etching by use of silicon tetrachloride as the sole etching gas.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: July 22, 2008
    Assignee: Show a Denko K.K.
    Inventors: Munetaka Watanabe, Noritaka Muraki, Yasushi Ohno
  • Patent number: 7399994
    Abstract: A transparent electrode for use in a gallium nitride-based compound semiconductor light-emitting device having an emission wavelength of 440 nm or less, includes a metal layer disposed in contiguity to a p-type semiconductor layer and a current diffusion layer disposed on the metal layer. The transparent electrode contains substantially no Au in the whole region thereof. The metal layer contains any one element selected from the group consisting of Pt, Ir, Ru and Rh as a main component. The current diffusion layer contains any one element selected from the group consisting of Pt, Ir, Ru and Rh as a main component except for the case where the metal layer and the current diffusion layer have the same composition. It is possible to provide a white light-emitting device provided with the transparent electrode, a white light-emitting lamp using the white light-emitting device and a lighting fixture using the white light-emitting lamp.
    Type: Grant
    Filed: February 7, 2006
    Date of Patent: July 15, 2008
    Assignee: Showa Denka K.K.
    Inventors: Noritaka Muraki, Munetaka Watanabe, Yasushi Ohono, Hisayuki Miki
  • Publication number: 20080048172
    Abstract: A gallium nitride compound semiconductor light-emitting device includes a crystalline substrate (10), a light-emiting layer (15) of a quantum well structure which is formed of a gallium nitride compound semiconductor barrier layer and a gallium nitride compound semiconductor well layer, which light-emitting layer is provided on a second side of the crystalline substrate, a contact layer (17) formed of a Group III-V compound semiconductor for providing an Ohmic electrode for supplying device operation current to the light-emitting layer, and an Ohmic electrode (18) which is provided on the contact layer and has an aperture through which a portion of the contact layer is exposed. The Ohmic electrode exhibits light permeability with respect to light emitted from the light-emitting layer. The well layer contains a thick portion having a large thickness and a thin portion having a small thickness.
    Type: Application
    Filed: January 28, 2005
    Publication date: February 28, 2008
    Applicant: SHOWA DENKO K.K.
    Inventors: Noritaka Muraki, Munetaka Watanabe, Hisayuki Miki, Yasushi Ohno
  • Publication number: 20080042159
    Abstract: A transparent electrode for a gallium nitride-based compound semiconductor light-emitting device includes a p-type semiconductor layer (5), a contact metal layer (1) formed by ohmic contact on the p-type semiconductor layer, an current diffusion layer (12) formed on the contact metal layer and having a lower magnitude of resistivity on the plane of the transparent electrode than the contact metal, and a bonding pad (13) formed on the current diffusion layer. The transparent electrode is at an advantage in widening the surface of light emission in the p-type semiconductor layer, decreasing the operation voltage in the forward direction, and enabling the bonding pad to provide excellent adhesive strength.
    Type: Application
    Filed: July 27, 2005
    Publication date: February 21, 2008
    Applicant: SHOWA DENKO K.K
    Inventors: Nobuo Eitoh, Noritaka Muraki, Hisayuki Miki, Munetaka Watanabe
  • Publication number: 20070200129
    Abstract: An object of the present invention is to provide a positive electrode having high transparency, low contact resistance and excellent current diffusibility and not requiring electron beam irradiation, high-temperature annealing or heat treatment, for alloying, in an oxygen atmosphere. The inventive transparent positive electrode for gallium nitride-based compound semiconductor light-emitting devices comprises a contact metal layer in contact with a p-type semiconductor layer, a current diffusing layer on the contact metal layer, the current diffusing layer having an electrical conductivity larger than that of the contact metal layer, and a bonding pad layer on the current diffusing layer.
    Type: Application
    Filed: April 28, 2005
    Publication date: August 30, 2007
    Applicant: SHOWA DENKO K.K.
    Inventors: Munetaka Watanabe, Noritaka Muraki, Koji Kamei, Yasushi Ohno
  • Publication number: 20070187666
    Abstract: An object of the present invention is to provide a gallium nitride compound semiconductor light-emitting device having excellent heat resistance, which device is resistive to an increase in the forward operation voltage (VF) caused by mild heating performed after formation of the light-emitting device (e.g., heating to about 300° C. during mounting of the light-emitting device).
    Type: Application
    Filed: March 15, 2005
    Publication date: August 16, 2007
    Applicant: SHOWA DENKO K.K.
    Inventors: Munetaka Watanabe, Noritaka Muraki, Yasushi Ohno
  • Publication number: 20070126008
    Abstract: An object of the present invention is to provide a flip-chip-type gallium nitride compound semiconductor light-emitting device exhibiting excellent ohmic characteristics, excellent bonding characteristics, and high emission output. The inventive flip-chip-type gallium nitride compound semiconductor light-emitting device comprises a positive electrode which has a three-layer structure comprising an ohmic electrode layer composed of rhodium which is in contact with the p-type semiconductor layer, an adhesion layer composed of titanium which is provided on the ohmic electrode layer and has a thickness of 10 ? or more, and a bonding pad layer provided on the adhesion layer and being composed of a metal selected from the group consisting of gold, aluminum, nickel, and copper, or composed of an alloy containing at least one of these metals.
    Type: Application
    Filed: October 13, 2004
    Publication date: June 7, 2007
    Inventor: Munetaka Watanabe
  • Publication number: 20070080365
    Abstract: An object of the present invention is to provide a flip-chip-type gallium nitride compound semiconductor light-emitting device exhibiting excellent ohmic characteristics, excellent bonding characteristics, and high emission output.
    Type: Application
    Filed: October 13, 2004
    Publication date: April 12, 2007
    Applicant: SHOWA DENKO K.K.
    Inventor: Munetaka Watanabe
  • Publication number: 20060175682
    Abstract: A transparent electrode for use in a gallium nitride-based compound semiconductor light-emitting device having an emission wavelength of 440 nm or less, includes a metal layer disposed in contiguity to a p-type semiconductor layer and a current diffusion layer disposed on the metal layer. The transparent electrode contains substantially no Au in the whole region thereof. The metal layer contains any one element selected from the group consisting of Pt, Ir, Ru and Rh as a main component. The current diffusion layer contains any one element selected from the group consisting of Pt, Ir, Ru and Rh as a main component except for the case where the metal layer and the current diffusion layer have the same composition. It is possible to provide a white light-emitting device provided with the transparent electrode, a white light-emitting lamp using the white light-emitting device and a lighting fixture using the white light-emitting lamp.
    Type: Application
    Filed: February 7, 2006
    Publication date: August 10, 2006
    Inventors: Noritaka Muraki, Munetaka Watanabe, Yasushi Ohono, Hisayuki Miki