Patents by Inventor Mikio Tazima

Mikio Tazima 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: 7897497
    Abstract: A light-generating semiconductor region is grown by epitaxy on a silicon substrate. The light-generating semiconductor region is a lamination of layers of semiconducting nitrides containing a Group III element or elements. The silicon substrate has a p-type impurity-diffused layer formed therein by thermal diffusion of the Group III element or elements from the light-generating semiconductor region as a secondary product of the epitaxial growth of this region on the substrate. The p-type impurity-diffused layer is utilized as a part of overvoltage protector diodes which are serially interconnected with each other and in parallel with the LED section of the device between a pair of electrodes.
    Type: Grant
    Filed: July 28, 2008
    Date of Patent: March 1, 2011
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Yasuhiro Kamii, Arei Niwa, Junji Sato, Mikio Tazima
  • Patent number: 7893450
    Abstract: An aspect of the present invention inheres in a semiconductor light-emitting element includes a light-emitting functional stacked body including a light-emitting region having a light-emitting function, and including a light extraction surface for extracting light emitted from the light-emitting region, and an upward convex lens disposed on the light extraction surface.
    Type: Grant
    Filed: July 9, 2008
    Date of Patent: February 22, 2011
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Mikio Tazima, Yoshiki Tada, Tetsuji Matsuo
  • Patent number: 7723732
    Abstract: A semiconductor light-emitting device includes a substrate having two main surfaces; and an active layer forming part, which is made of a compound semiconductor material, formed on one of the main surfaces, and includes an active layer. A plurality of holes, which pass through the active layer, are formed from the upper surface of the active layer forming part; a plurality of hollow parts, each of which corresponds to each hole, are provided between the active layer and the substrate; and the area of each hollow part is larger than that of the corresponding hole in plan view, and spreads on the lower surface of the active layer forming part, so as to expose a part of the lower surface of the active layer forming part, which overlaps the hollow part in plan view.
    Type: Grant
    Filed: November 7, 2007
    Date of Patent: May 25, 2010
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Mikio Tazima, Yoshiki Tada
  • Patent number: 7687323
    Abstract: The method is disclosed as applied to roughening the light-emitting surface of an LED wafer for reduction of the internal total reflection of the light generated. A masking film of silver is first deposited on the surface of a wafer to be diced into LED chips. Then the masking film is heated to cause its coagulation into discrete particles. Then, using the silver particles as a mask, the wafer surface is dry etched to create pits therein. The deposition of silver on the wafer surface and its thermal coagulation into particles may be either successive or concurrent.
    Type: Grant
    Filed: April 16, 2008
    Date of Patent: March 30, 2010
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Tetsuji Matsuo, Mikio Tazima, Takashi Kato
  • Publication number: 20090026476
    Abstract: An aspect of the present invention inheres in a semiconductor light-emitting element includes a light-emitting functional stacked body including a light-emitting region having a light-emitting function, and including a light extraction surface for extracting light emitted from the light-emitting region, and an upward convex lens disposed on the light extraction surface.
    Type: Application
    Filed: July 9, 2008
    Publication date: January 29, 2009
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Mikio Tazima, Yoshiki Tada, Tetsuji Matsuo
  • Publication number: 20080308823
    Abstract: A light-generating semiconductor region is grown by epitaxy on a silicon substrate. The light-generating semiconductor region is a lamination of layers of semiconducting nitrides containing a Group III element or elements. The silicon substrate has a p-type impurity-diffused layer formed therein by thermal diffusion of the Group III element or elements from the light-generating semiconductor region as a secondary product of the epitaxial growth of this region on the substrate. The p-type impurity-diffused layer is utilized as a part of overvoltage protector diodes which are serially interconnected with each other and in parallel with the LED section of the device between a pair of electrodes.
    Type: Application
    Filed: July 28, 2008
    Publication date: December 18, 2008
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Yasuhiro Kamii, Arei Niwa, Junji Sato, Mikio Tazima
  • Patent number: 7449727
    Abstract: An LED incorporating an overvoltage protector with a minimum of space requirement. The LED itself comprises a p-type semiconductor substrate, a light-generating semiconductor region grown epitaxially thereon, a first electrode on the light-generating semiconductor region, and a second electrode on the underside of the substrate. The standard method of LED fabrication is such that the substrate is notionally divisible into a main portion in register with the overlying light-generating semiconductor region and, surrounding the main portion, a tubular marginal portion needed for dicing the wafer into individual squares or dice. The overvoltage protector comprises an n-type semiconductor film formed on the marginal portion of the substrate and held against the side surfaces of the light-generating semiconductor region via an insulating film.
    Type: Grant
    Filed: January 31, 2006
    Date of Patent: November 11, 2008
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Junji Sato, Mikio Tazima, Tetsuji Moku, Arei Niwa, Yasuhiro Kamii
  • Patent number: 7446342
    Abstract: There is provided a semiconductor light emitting diode and a method of manufacturing the same that enable voltage in the forward direction to be decreased while allowing light extraction efficiency to be improved. This semiconductor light emitting diode is formed by a substrate, a light emitting portion that is disposed on one main surface of the substrate, a first electrode that is disposed on the light emitting portion, a pad electrode that is disposed on the first electrode, concave portions that are formed on at least a portion of the one main surface of the substrate, and a conductive layer that is formed from a conductive material that is disposed in the concave portions and reflects light emitted from the light emitting portion.
    Type: Grant
    Filed: February 8, 2006
    Date of Patent: November 4, 2008
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Mikio Tazima, Tetsuji Moku, Junji Sato, Yasuhiro Kamii, Arei Niwa
  • Publication number: 20080261340
    Abstract: The method is disclosed as applied to roughening the light-emitting surface of an LED wafer for reduction of the internal total reflection of the light generated. A masking film of silver is first deposited on the surface of a wafer to be diced into LED chips. Then the masking film is heated to cause its coagulation into discrete particles. Then, using the silver particles as a mask, the wafer surface is dry etched to create pits therein. The deposition of silver on the wafer surface and its thermal coagulation into particles may be either successive or concurrent.
    Type: Application
    Filed: April 16, 2008
    Publication date: October 23, 2008
    Applicant: SANKEN ELECTRIC CO., LTD.
    Inventors: Tetsuji Matsuo, Mikio Tazima, Takashi Kato
  • Publication number: 20080128716
    Abstract: A semiconductor light-emitting device includes a substrate having two main surfaces; and an active layer forming part, which is made of a compound semiconductor material, formed on one of the main surfaces, and includes an active layer. A plurality of holes, which pass through the active layer, are formed from the upper surface of the active layer forming part; a plurality of hollow parts, each of which corresponds to each hole, are provided between the active layer and the substrate; and the area of each hollow part is larger than that of the corresponding hole in plan view, and spreads on the lower surface of the active layer forming part, so as to expose a part of the lower surface of the active layer forming part, which overlaps the hollow part in plan view.
    Type: Application
    Filed: November 7, 2007
    Publication date: June 5, 2008
    Applicant: SANKEN ELECTRIC CO., LTD.
    Inventors: Mikio Tazima, Yoshiki Tada
  • Publication number: 20080048202
    Abstract: A semiconductor device may include, but is not limited to, a substrate, a compound semiconductor epitaxial layer, and a first reflecting layer. The substrate may have a main face. The substrate may have at least one cavity that is adjacent to the main face. The compound semiconductor epitaxial layer may have first and second faces adjacent to each other. The first face may contact with the main face. The second face may face toward the at least one cavity. The compound semiconductor epitaxial layer may include, but is not limited to, at least one light emitting layer that emits light. The first reflecting layer may be in the at least one cavity. The first reflecting layer may contact with the second face. The first reflecting layer may be higher in light-reflectivity than the substrate.
    Type: Application
    Filed: July 24, 2007
    Publication date: February 28, 2008
    Applicant: SANKEN ELECTRIC CO., LTD.
    Inventors: Mikio Tazima, Yoshiki Tada, Yasuhiro Kamii
  • Publication number: 20070114515
    Abstract: An LED is disclosed which comprises a nitride-made main semiconductor region formed on a substrate for generating light, and an electrode formed on the main semiconductor region to a thickness sufficiently small to transmit the light from the main semiconductor region. The electrode is made from a silver-base alloy, rather than from silver only, that contains an additive or additives selected to protect the electrode against oxidation and/or sulfurization and to enhance the chemical stability of the electrode without loss in contact ohmicity.
    Type: Application
    Filed: January 15, 2007
    Publication date: May 24, 2007
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Hidekazu Aoyagi, Tetsuji Matsuo, Tetsuji Moku, Mikio Tazima
  • Patent number: 7199401
    Abstract: An LED includes a semiconductor region having an active layer sandwiched between two confining layers of opposite conductivity types for generating heat. A cathode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. Attached to the other major surface of the semiconductor region, via an ohmic contact layer, is a reflective metal layer for reflecting the light that has traversed the ohmic contact layer, back toward the semiconductor region. A transparent antidiffusion layer is interposed between the ohmic contact layer and the reflective layer in order to prevent the ohmic contact layer and the reflective layer from thermally diffusing from one into the other to the impairment of the reflectivity of the reflective layer.
    Type: Grant
    Filed: February 16, 2005
    Date of Patent: April 3, 2007
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Mikio Tazima, Masahiro Sato, Hidekazu Aoyagi, Tetsuji Matsuo
  • Publication number: 20060193355
    Abstract: There is provided a semiconductor light emitting diode and a method of manufacturing the same that enable voltage in the forward direction to be decreased while allowing light extraction efficiency to be improved. This semiconductor light emitting diode is formed by a substrate, a light emitting portion that is disposed on one main surface of the substrate, a first electrode that is disposed on the light emitting portion, a pad electrode that is disposed on the first electrode, concave portions that are formed on at least a portion of the one main surface of the substrate, and a conductive layer that is formed from a conductive material that is disposed in the concave portions and reflects light emitted from the light emitting portion.
    Type: Application
    Filed: February 8, 2006
    Publication date: August 31, 2006
    Applicant: Sanken Electric Co., LTD.
    Inventors: Mikio Tazima, Tetsuji Moku, Junji Sato, Yasuhiro Kamii, Arei Niwa
  • Publication number: 20060181828
    Abstract: An LED incorporating an overvoltage protector with a minimum of space requirement. The LED itself comprises a p-type semiconductor substrate, a light-generating semiconductor region grown epitaxially thereon, a first electrode on the light-generating semiconductor region, and a second electrode on the underside of the substrate. The standard method of LED fabrication is such that the substrate is notionally divisible into a main portion in register with the overlying light-generating semiconductor region and, surrounding the main portion, a tubular marginal portion needed for dicing the wafer into individual squares or dice. The overvoltage protector comprises an n-type semiconductor film formed on the marginal portion of the substrate and held against the side surfaces of the light-generating semiconductor region via an insulating film.
    Type: Application
    Filed: January 31, 2006
    Publication date: August 17, 2006
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Junji Sato, Mikio Tazima, Tetsuji Moku, Arei Niwa, Yasuhiro Kamii
  • Publication number: 20050184300
    Abstract: An LED includes a semiconductor region having an active layer sandwiched between two confining layers of opposite conductivity types for generating heat. A cathode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. Attached to the other major surface of the semiconductor region, via an ohmic contact layer, is a reflective metal layer for reflecting the light that has traversed the ohmic contact layer, back toward the semiconductor region. A transparent antidiffusion layer is interposed between the ohmic contact layer and the reflective layer in order to prevent the ohmic contact layer and the reflective layer from thermally diffusing from one into the other to the impairment of the reflectivity of the reflective layer.
    Type: Application
    Filed: February 16, 2005
    Publication date: August 25, 2005
    Inventors: Mikio Tazima, Masahiro Sato, Hidekazu Aoyagi, Tetsuji Matsuo