Patents by Inventor Yoshibumi Nakajima

Yoshibumi Nakajima 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: 7005688
    Abstract: A semiconductor switching device includes a plurality of metal layers. At least one of the metal layers forming a Schottky junction with a semi-insulating substrate or an insulating layer on a substrate. The device also includes an impurity diffusion region, and a high-concentration impurity region formed between two of the metal layers or between one of the metal layers and the impurity diffusion region so as to suppress expansion of a depletion layer from the corresponding metal layer.
    Type: Grant
    Filed: October 14, 2003
    Date of Patent: February 28, 2006
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Yoshibumi Nakajima, Hidetoshi Ishihara
  • Publication number: 20050179106
    Abstract: A Schottky barrier diode has a Schottky electrode formed on an operation region of a GaAs substrate and an ohmic electrode surrounding the Schottky electrode. The ohmic electrode is disposed directly on an impurity-implanted region formed on the substrate. A nitride film insulates the ohmic electrode from a wiring layer connected to the Schottky electrode crossing over the ohmic electrode. The planar configuration of this device does not include the conventional polyimide layer, and thus has a better high frequency characteristics than conventional devices.
    Type: Application
    Filed: April 12, 2005
    Publication date: August 18, 2005
    Applicant: Sanyo Electric Company, Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onoda, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Patent number: 6914280
    Abstract: Since a 5 GHz-band broadband has a frequency twice that of 2.4 GHz, the parasitic capacitance greatly influences deterioration in isolation of a switching device used in this frequency region. Therefore, to improve isolation, a shunt FET is added to the device. The switching device also includes a protecting element that has a first n+-type region, an insulating region and a second n+-type region. This protecting element is connected in parallel between two electrodes of the shunt FET. Since electrostatic charges are discharged between the first and second n+-type regions, the electrostatic energy reaching an operation region of the shunt FET can be reduced without an increase in parasitic capacitance.
    Type: Grant
    Filed: October 17, 2003
    Date of Patent: July 5, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Yoshibumi Nakajima, Hidetoshi Ishihara
  • Publication number: 20040211990
    Abstract: A semiconductor switching device includes a plurality of metal layers. At least one of the metal layers forming a Schottky junction with a semi-insulating substrate or an insulating layer on a substrate. The device also includes an impurity diffusion region, and a high-concentration impurity region formed between two of the metal layers or between one of the metal layers and the impurity diffusion region so as to suppress expansion of a depletion layer from the corresponding metal layer.
    Type: Application
    Filed: October 14, 2003
    Publication date: October 28, 2004
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Yoshibumi Nakajima, Hidetoshi Ishihara
  • Patent number: 6787871
    Abstract: An integrated Schottky barrier diode chip includes a compound semiconductor substrate, a plurality of Schottky barrier diodes formed on the substrate and an insulating region formed on the substrate by an on implantation. The insulating region electrically separates a portion of a diode at a cathode voltage from a portion of the diode at an anode voltage. Because of the absence of a polyimide layer and trench structures, this planar device configuration results in simpler manufacturing method and improved device characteristics.
    Type: Grant
    Filed: October 30, 2002
    Date of Patent: September 7, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onoda, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Patent number: 6777277
    Abstract: A Schottky barrier diode has a Schottky contact region formed in an n epitaxial layer disposed on a GaAs substrate and an ohmic electrode surrounding the Schottky contact region. The ohmic electrode is disposed directly on an impurity-implanted region formed on the substrate. An insulating region is formed through the n epitaxial layer so that an anode bonding pad is isolated form other elements of the device at a cathode voltage. The planar configuration of this device does not include the conventional polyimide layer, and thus has a better high frequency characteristics than conventional devices.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: August 17, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onoda, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Publication number: 20040130380
    Abstract: Since a 5 GHz-band broadband has a frequency twice that of 2.4 GHz, the parasitic capacitance greatly influences deterioration in isolation of a switching device used in this frequency region. Therefore, to improve isolation, a shunt FET is added to the device. The switching device also includes a protecting element that has a first n+-type region, an insulating region and a second n+-type region. This protecting element is connected in parallel between two electrodes of the shunt FET. Since electrostatic charges are discharged between the first and second n+-type regions, the electrostatic energy reaching an operation region of the shunt FET can be reduced without an increase in parasitic capacitance.
    Type: Application
    Filed: October 17, 2003
    Publication date: July 8, 2004
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Yoshibumi Nakajima, Hidetoshi Ishihara
  • Patent number: 6682968
    Abstract: A Schottky barrier diode has a Schottky electrode formed on an operation region of a GaAs substrate and an ohmic electrode surrounding the Schottky electrode. The ohmic electrode is disposed directly on an impurity-implanted region formed on the substrate. A nitride film insulates the ohmic electrode from a wiring layer connected to the Schottky electrode crossing over the ohmic electrode. The planar configuration of this device does not include the conventional polyimide layer, and thus has a better high frequency characteristics than conventional devices.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: January 27, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onoda, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Patent number: 6627967
    Abstract: A Schottky barrier diode has a Schottky contact region formed in an n epitaxial layer disposed on a GaAs substrate and an ohmic electrode surrounding the Schottky contact region. The ohmic electrode is disposed directly on an impurity-implanted region formed on the substrate. An insulating region is formed through the n epitaxial layer so that an anode bonding pad is isolated form other elements of the device at a cathode voltage. The planar configuration of this device does not include the conventional polyimide layer, and thus has a better high frequency characteristics than conventional devices.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: September 30, 2003
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onada, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Publication number: 20030094668
    Abstract: An integrated Schottky barrier diode chip includes a compound semiconductor substrate, a plurality of Schottky barrier diodes formed on the substrate and an insulating region formed on the substrate by an on implantation. The insulating region electrically separates a portion of a diode at a cathode voltage from a portion of the diode at an anode voltage. Because of the absence of a polyimide layer and trench structures, this planar device configuration results in simpler manufacturing method and improved device characteristics.
    Type: Application
    Filed: October 30, 2002
    Publication date: May 22, 2003
    Inventors: Tetsuro Asano, Katsuaki Onoda, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Publication number: 20030089959
    Abstract: A Schottky barrier diode has a Schottky contact region formed in an n epitaxial layer disposed on a GaAs substrate and an ohmic electrode surrounding the Schottky contact region. The ohmic electrode is disposed directly on an impurity-implanted region formed on the substrate. An insulating region is formed through the n epitaxial layer so that an anode bonding pad is isolated form other elements of the device at a cathode voltage. The planar configuration of this device does not include the conventional polyimide layer, and thus has a better high frequency characteristics than conventional devices.
    Type: Application
    Filed: July 26, 2002
    Publication date: May 15, 2003
    Applicant: Sanyo Electric Company, Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onada, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Publication number: 20030060031
    Abstract: A Schottky barrier diode has a Schottky contact region formed in an n epitaxial layer disposed on a GaAs substrate and an ohmic electrode surrounding the Schottky contact region. The ohmic electrode is disposed directly on an impurity-implanted region formed on the substrate. An insulating region is formed through the n epitaxial layer so that an anode bonding pad is isolated form other elements of the device at a cathode voltage. The planar configuration of this device does not include the conventional polyimide layer, and thus has a better high frequency characteristics than conventional devices.
    Type: Application
    Filed: July 26, 2002
    Publication date: March 27, 2003
    Applicant: Sanyo Electric Company, Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onada, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Publication number: 20030036252
    Abstract: A Schottky barrier diode has a Schottky electrode formed on an operation region of a GaAs substrate and an ohmic electrode surrounding the Schottky electrode. The ohmic electrode is disposed directly on an impurity-implanted region formed on the substrate. A nitride film insulates the ohmic electrode from a wiring layer connected to the Schottky electrode crossing over the ohmic electrode. The planar configuration of this device does not include the conventional polyimide layer, and thus has a better high frequency characteristics than conventional devices.
    Type: Application
    Filed: July 26, 2002
    Publication date: February 20, 2003
    Applicant: Sanyo Electric Company, Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onoda, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Publication number: 20030025175
    Abstract: A Schottky barrier diode has a Schottky electrode formed on an operation region of a GaAs substrate and an ohmic electrode surrounding the Schottky electrode. The ohmic electrode is disposed directly on an impurity-implanted region formed on the substrate. A nitride film insulates the ohmic electrode from a wiring layer connected to the Schottky electrode crossing over the ohmic electrode. The planar configuration of this device does not include the conventional polyimide layer, and thus has a better high frequency characteristics than conventional devices.
    Type: Application
    Filed: July 26, 2002
    Publication date: February 6, 2003
    Applicant: Sanyo Electric Company, Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onoda, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara