Patents by Inventor Isao Obu

Isao Obu 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: 20170243939
    Abstract: A high-performance HBT that is unlikely to decrease the process controllability and to increase the manufacturing cost is implemented. A heterojunction bipolar transistor includes an emitter layer, a base layer, and a collector layer on a GaAs substrate. The emitter layer is formed of InGaP. The base layer is formed of GaAsPBi having a composition that substantially lattice-matches GaAs.
    Type: Application
    Filed: May 8, 2017
    Publication date: August 24, 2017
    Applicant: MURATA MANUFACTURING CO., LTD.
    Inventors: Isao OBU, Shigeru YOSHIDA
  • Publication number: 20170236796
    Abstract: A bump-equipped electronic component includes a circuit substrate and first and second bumps which are disposed on a principal surface of the circuit substrate and have different cross-sectional areas in a direction parallel or substantially parallel to the principal surface. One of the first and second bumps having a smaller cross-sectional area includes a height adjustment layer disposed in a direction perpendicular or substantially perpendicular to the principal surface.
    Type: Application
    Filed: May 5, 2017
    Publication date: August 17, 2017
    Inventors: Isao OBU, Shinya OSAKABE
  • Patent number: 9679860
    Abstract: A bump-equipped electronic component includes a circuit substrate and first and second bumps which are disposed on a principal surface of the circuit substrate and have different cross-sectional areas in a direction parallel or substantially parallel to the principal surface. One of the first and second bumps having a smaller cross-sectional area includes a height adjustment layer disposed in a direction perpendicular or substantially perpendicular to the principal surface.
    Type: Grant
    Filed: March 15, 2016
    Date of Patent: June 13, 2017
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Isao Obu, Shinya Osakabe
  • Patent number: 9397204
    Abstract: A heterojunction bipolar transistor includes a collector layer composed of a semiconductor containing GaAs as a main component; a base layer including a first base layer and a second base layer the first base layer forming a heterojunction with the collector layer and being composed of a semiconductor containing a material as a main component, the material being lattice-mismatched to the main component of the collector layer, the first base layer having a film thickness less than a critical thickness at which a misfit dislocation is introduced, the second base layer being joined to the first base layer and composed of a semiconductor containing a material as a main component, and the material being lattice-matched to the main component of the collector layer; and an emitter layer that forms a heterojunction with the second base layer.
    Type: Grant
    Filed: September 8, 2015
    Date of Patent: July 19, 2016
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Isao Obu, Yasunari Umemoto, Atsushi Kurokawa
  • Publication number: 20160197052
    Abstract: A bump-equipped electronic component includes a circuit substrate and first and second bumps which are disposed on a principal surface of the circuit substrate and have different cross-sectional areas in a direction parallel or substantially parallel to the principal surface. One of the first and second bumps having a smaller cross-sectional area includes a height adjustment layer disposed in a direction perpendicular or substantially perpendicular to the principal surface.
    Type: Application
    Filed: March 15, 2016
    Publication date: July 7, 2016
    Inventors: Isao OBU, Shinya OSAKABE
  • Patent number: 9343360
    Abstract: A bump-equipped electronic component includes a circuit substrate and first and second bumps which are disposed on a principal surface of the circuit substrate and have different cross-sectional areas in a direction parallel or substantially parallel to the principal surface. One of the first and second bumps having a smaller cross-sectional area includes a height adjustment layer disposed in a direction perpendicular or substantially perpendicular to the principal surface.
    Type: Grant
    Filed: December 4, 2013
    Date of Patent: May 17, 2016
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Isao Obu, Shinya Osakabe
  • Publication number: 20160005841
    Abstract: A heterojunction bipolar transistor includes a collector layer composed of a semiconductor containing GaAs as a main component; a base layer including a first base layer and a second base layer the first base layer forming a heterojunction with the collector layer and being composed of a semiconductor containing a material as a main component, the material being lattice-mismatched to the main component of the collector layer, the first base layer having a film thickness less than a critical thickness at which a misfit dislocation is introduced, the second base layer being joined to the first base layer and composed of a semiconductor containing a material as a main component, and the material being lattice-matched to the main component of the collector layer; and an emitter layer that forms a heterojunction with the second base layer.
    Type: Application
    Filed: September 8, 2015
    Publication date: January 7, 2016
    Applicant: MURATA MANUFACTURING CO., LTD.
    Inventors: Isao OBU, Yasunari UMEMOTO, Atsushi KUROKAWA
  • Patent number: 9130004
    Abstract: A heterojunction bipolar transistor includes a ballast resistor layer of which resistance increases with an increase in temperature. The ballast resistor layer includes a first ballast resistor sub-layer having a positive temperature coefficient of resistivity in a first temperature range and a second temperature range and a second ballast resistor sub-layer having a negative temperature coefficient of resistivity in the first temperature range and a positive temperature coefficient of resistivity in the second temperature range.
    Type: Grant
    Filed: November 25, 2013
    Date of Patent: September 8, 2015
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Isao Obu, Yasunari Umemoto, Atsushi Kurokawa
  • Publication number: 20140167115
    Abstract: A heterojunction bipolar transistor includes a ballast resistor layer of which resistance increases with an increase in temperature. The ballast resistor layer includes a first ballast resistor sub-layer having a positive temperature coefficient of resistivity in a first temperature range and a second temperature range and a second ballast resistor sub-layer having a negative temperature coefficient of resistivity in the first temperature range and a positive temperature coefficient of resistivity in the second temperature range.
    Type: Application
    Filed: November 25, 2013
    Publication date: June 19, 2014
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Isao OBU, Yasunari UMEMOTO, Atsushi KUROKAWA
  • Publication number: 20140151874
    Abstract: A bump-equipped electronic component includes a circuit substrate and first and second bumps which are disposed on a principal surface of the circuit substrate and have different cross-sectional areas in a direction parallel or substantially parallel to the principal surface. One of the first and second bumps having a smaller cross-sectional area includes a height adjustment layer disposed in a direction perpendicular or substantially perpendicular to the principal surface.
    Type: Application
    Filed: December 4, 2013
    Publication date: June 5, 2014
    Applicant: MURATA MANUFACTURING CO., LTD.
    Inventors: Isao OBU, Shinya OSAKABE
  • Patent number: 7723753
    Abstract: In a GaAs substrate as a semi-insulating substrate, a heterojunction bipolar transistor (HBT) is formed in an element formation region, while an isolation region is formed in an insulating region. The isolation region formed in the insulating region is formed by introducing helium into the same semiconductor layers as the sub-collector semiconductor layer and collector semiconductor layer of the HBT. In an outer peripheral region, a conductive layer is formed to be exposed from protective films and coupled to a back surface electrode. Because a GND potential is supplied to the back surface electrode, the conductive layer is fixed to the GND potential. The conductive layer is formed of the same semiconductor layers as the sub-collector semiconductor layer and collector semiconductor layer of the HBT.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: May 25, 2010
    Assignee: Renesas Technology Corp.
    Inventors: Kenji Sasaki, Ikuro Akazawa, Yoshinori Imamura, Atsushi Kurokawa, Tatsuhiko Ikeda, Hiroshi Inagawa, Yasunari Umemoto, Isao Obu
  • Publication number: 20090085162
    Abstract: The present invention provides a semiconductor device that includes a plurality of transistor cells and makes it possible to achieve higher degree of integration and lower cost of an integrated semiconductor circuit device as the first object, and provide an integrated semiconductor circuit device of high density integration and compact construction at a low cost.
    Type: Application
    Filed: September 25, 2008
    Publication date: April 2, 2009
    Inventors: Atsushi Kurokawa, Kenji Sasaki, Isao Obu, Satoshi Suzuki
  • Publication number: 20080224174
    Abstract: A technology which allows an improvement in the moisture resistance of a semiconductor device is provided. In a GaAs substrate as a semi-insulating substrate, a HBT is formed in an element formation region, while an isolation region is formed in an insulating region. The isolation region formed in the insulating region is formed by introducing helium into the same semiconductor layers as the sub-collector semiconductor layer and collector semiconductor layer of the HBT. In an outer peripheral region, a conductive layer is formed to be exposed from protective films and coupled to a back surface electrode. Because a GND potential is supplied to the back surface electrode, the conductive layer is fixed to the GND potential. The conductive layer is formed of the same semiconductor layers as the sub-collector semiconductor layer and collector semiconductor layer of the HBT.
    Type: Application
    Filed: December 21, 2007
    Publication date: September 18, 2008
    Inventors: Kenji SASAKI, Ikuro Akazawa, Yoshinori Imamura, Atsushi Kurokawa, Tatsuhiko Ikeda, Hiroshi Inagawa, Yasunari Umemoto, Isao Obu