Patents by Inventor Masakatsu Takashita

Masakatsu Takashita 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: 8907420
    Abstract: A power semiconductor device includes: a first semiconductor layer of a first conductivity type; a second semiconductor layer of the first conductivity type and a third semiconductor layer of a second conductivity type formed on the first semiconductor layer and alternately arranged along at least one direction parallel to a surface of the first semiconductor layer; a first main electrode; a fourth semiconductor layer of the second conductivity type selectively formed in a surface of the second semiconductor layer and a surface of the third semiconductor layer; a fifth semiconductor layer of the first conductivity type selectively formed in a surface of the fourth semiconductor layer; a second main electrode; and a control electrode. At least one of the second and the third semiconductor layers has a dopant concentration profile along the one direction, the dopant concentration profile having a local minimum at a position except both ends thereof.
    Type: Grant
    Filed: May 27, 2010
    Date of Patent: December 9, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wataru Saito, Syotaro Ono, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta
  • Patent number: 8283720
    Abstract: A power semiconductor device includes: a first semiconductor layer; a second semiconductor layer and a third semiconductor layer provided in an upper portion of the first semiconductor layer and alternately arranged parallel to an upper surface of the first semiconductor layer; a plurality of fourth semiconductor layers provided on the third semiconductor layer; a fifth semiconductor layer selectively formed in an upper surface of each of the fourth semiconductor layers; a control electrode; a gate insulating film; a first main electrode provided on a lower surface of the first semiconductor layer; and a second main electrode provided on the fourth and the fifth semiconductor layers.
    Type: Grant
    Filed: March 18, 2008
    Date of Patent: October 9, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wataru Saito, Syotaro Ono, Masakatsu Takashita, Yauto Sumi, Masaru Izumisawa, Wataru Sekine, Hiroshi Ohta, Shoichiro Kurushima
  • Patent number: 8227854
    Abstract: A semiconductor device includes: a drift layer having a superjunction structure; a semiconductor base layer selectively formed in a part of one surface of the drift layer; a first RESURF layer formed around a region having the semiconductor base layer formed thereon; a second semiconductor RESURF layer of a conductivity type which is opposite to a conductivity type of the first semiconductor RESURF layer; a first main electrode connected to a first surface of the drift layer; and a second main electrode connected to a second surface of the drift layer. The first RESURF layer is connected to the semiconductor base layer. The second semiconductor RESURF layer is in contact with the first semiconductor RESURF layer.
    Type: Grant
    Filed: November 7, 2007
    Date of Patent: July 24, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Syotaro Ono, Wataru Saito, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta
  • Patent number: 8013360
    Abstract: A semiconductor device includes: a semiconductor layer of a first conductivity type; a first semiconductor pillar region of the first conductivity type provided on a major surface of the semiconductor layer; a second semiconductor pillar region of a second conductivity type provided adjacent to the first semiconductor pillar region on the major surface of the semiconductor layer, the second semiconductor pillar region forming a periodic arrangement structure substantially parallel to the major surface of the semiconductor layer together with the first semiconductor pillar region; a first main electrode; a first semiconductor region of the second conductivity type; a second semiconductor region of the first conductivity type; a second main electrode; a control electrode; and a high-resistance semiconductor layer provided on the semiconductor layer in an edge termination section surrounding the first semiconductor pillar region and the second semiconductor pillar region.
    Type: Grant
    Filed: April 21, 2010
    Date of Patent: September 6, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wataru Saito, Syotaro Ono, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta, Wataru Sekine
  • Publication number: 20100230750
    Abstract: A power semiconductor device includes: a first semiconductor layer of a first conductivity type; a second semiconductor layer of the first conductivity type and a third semiconductor layer of a second conductivity type formed on the first semiconductor layer and alternately arranged along at least one direction parallel to a surface of the first semiconductor layer; a first main electrode; a fourth semiconductor layer of the second conductivity type selectively formed in a surface of the second semiconductor layer and a surface of the third semiconductor layer; a fifth semiconductor layer of the first conductivity type selectively formed in a surface of the fourth semiconductor layer; a second main electrode; and a control electrode. At least one of the second and the third semiconductor layers has a dopant concentration profile along the one direction, the dopant concentration profile having a local minimum at a position except both ends thereof.
    Type: Application
    Filed: May 27, 2010
    Publication date: September 16, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Wataru SAITO, Syotaro Ono, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta
  • Publication number: 20100200936
    Abstract: A semiconductor device includes: a semiconductor layer of a first conductivity type; a first semiconductor pillar region of the first conductivity type provided on a major surface of the semiconductor layer; a second semiconductor pillar region of a second conductivity type provided adjacent to the first semiconductor pillar region on the major surface of the semiconductor layer, the second semiconductor pillar region forming a periodic arrangement structure substantially parallel to the major surface of the semiconductor layer together with the first semiconductor pillar region; a first main electrode; a first semiconductor region of the second conductivity type; a second semiconductor region of the first conductivity type; a second main electrode; a control electrode; and a high-resistance semiconductor layer provided on the semiconductor layer in an edge termination section surrounding the first semiconductor pillar region and the second semiconductor pillar region.
    Type: Application
    Filed: April 21, 2010
    Publication date: August 12, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Wataru SAITO, Syotaro Ono, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta, Wataru Sekine
  • Patent number: 7759732
    Abstract: A power semiconductor device includes: a first semiconductor layer of a first conductivity type; a second semiconductor layer of the first conductivity type and a third semiconductor layer of a second conductivity type formed on the first semiconductor layer and alternately arranged along at least one direction parallel to a surface of the first semiconductor layer; a first main electrode; a fourth semiconductor layer of the second conductivity type selectively formed in a surface of the second semiconductor layer and a surface of the third semiconductor layer; a fifth semiconductor layer of the first conductivity type selectively formed in a surface of the fourth semiconductor layer; a second main electrode; and a control electrode. At least one of the second and the third semiconductor layers has a dopant concentration profile along the one direction, the dopant concentration profile having a local minimum at a position except both ends thereof.
    Type: Grant
    Filed: March 1, 2007
    Date of Patent: July 20, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wataru Saito, Syotaro Ono, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta
  • Patent number: 7737469
    Abstract: A semiconductor device includes: a semiconductor layer of a first conductivity type; a first semiconductor pillar region of the first conductivity type provided on a major surface of the semiconductor layer; a second semiconductor pillar region of a second conductivity type provided adjacent to the first semiconductor pillar region on the major surface of the semiconductor layer, the second semiconductor pillar region forming a periodic arrangement structure substantially parallel to the major surface of the semiconductor layer together with the first semiconductor pillar region; a first main electrode; a first semiconductor region of the second conductivity type; a second semiconductor region of the first conductivity type; a second main electrode; a control electrode; and a high-resistance semiconductor layer provided on the semiconductor layer in an edge termination section surrounding the first semiconductor pillar region and the second semiconductor pillar region.
    Type: Grant
    Filed: May 15, 2007
    Date of Patent: June 15, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wataru Saito, Syotaro Ono, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta, Wataru Sekine
  • Publication number: 20090302376
    Abstract: A semiconductor device includes: a first semiconductor layer of a first conductivity type having a first surface and a second surface opposite to the first surface, a cell region, and a terminal region surrounding the cell region, the cell region being configured to allow a current to flow between the first surface and the second surface; a first guard ring layer of a second conductivity type selectively formed in a surface portion of the first semiconductor layer in the terminal region, the first guard ring layer having a bottom surface thereof and internal and external side surfaces thereof; and a second guard ring layer of the second conductivity type selectively formed in the surface portion of the first semiconductor layer in the terminal region so as to cover a portion of the first guard ring layer at which the bottom surface and the external side surface intersect.
    Type: Application
    Filed: May 28, 2009
    Publication date: December 10, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Naoyuki INOUE, Wataru SAITO, Satoshi AIDA, Masakatsu TAKASHITA, Koichi ARATANI
  • Patent number: 7622771
    Abstract: A semiconductor apparatus includes a first semiconductor layer, a second semiconductor layer provided on a major surface of the first semiconductor layer, a third semiconductor layer provided on the major surface and being adjacent to the second semiconductor layer, a termination semiconductor layer provided on the major surface of the first semiconductor layer in a termination region outside the device region, a channel stop layer, and a channel stop electrode. The channel stop layer is provided in contact with the termination semiconductor layer on the major surface of the first semiconductor layer in an outermost peripheral portion outside the termination semiconductor layer and has a higher impurity concentration than the termination semiconductor layer. The channel stop electrode is provided on at least part of a surface of the channel stop layer and projects toward the termination semiconductor layer beyond at least a superficial portion of the channel stop layer.
    Type: Grant
    Filed: May 19, 2008
    Date of Patent: November 24, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Syotaro Ono, Wataru Saito, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta, Wataru Sekine
  • Publication number: 20090273031
    Abstract: A semiconductor device includes: a first semiconductor layer of a first conductivity type; a second semiconductor layer of the first conductivity type provided on a major surface of the first semiconductor layer; a third semiconductor layer of a second conductivity type provided on the major surface of the first semiconductor layer, the third semiconductor layer forming a structure of periodical arrangement with the second semiconductor layer; a fourth semiconductor layer of the second conductivity type provided above the third semiconductor layer; a fifth semiconductor layer of the first conductivity type selectively provided on a surface of the fourth semiconductor layer; a first main electrode electrically connected to the first semiconductor layer; a second main electrode provided to contact a surface of the fifth semiconductor layer and a surface of the fourth semiconductor layer; and a control electrode provided above the fifth semiconductor layer, the fourth semiconductor layer, and the second semicond
    Type: Application
    Filed: March 20, 2009
    Publication date: November 5, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Wataru SAITO, Syotaro ONO, Nana HATANO, Masakatsu TAKASHITA, Hiroshi OHTA, Miho WATANABE
  • Patent number: 7605426
    Abstract: A power semiconductor device includes: a semiconductor substrate; a gate insulating film; a control electrode insulated from the semiconductor substrate by the gate insulating film; a first main electrode provided on a lower surface side of the semiconductor substrate; and a second main electrode provided on an upper surface side of the semiconductor substrate.
    Type: Grant
    Filed: November 1, 2007
    Date of Patent: October 20, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wataru Saito, Syotaro Ono, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta
  • Publication number: 20080315297
    Abstract: There is provided a semiconductor device having a drift layer with a pillar structure including first semiconductor layer portions of the first conduction type and second semiconductor layer portions of the second conduction type formed in pillars alternately and periodically on a semiconductor substrate. A device region includes a plurality of arrayed transistors composed of the first semiconductor layer portions and the second semiconductor layer portions. A terminal region is formed at the periphery of the device region without the transistors formed therein. The drift layer in the terminal region has a carrier lifetime lower than ? the carrier lifetime in the drift layer in the device region.
    Type: Application
    Filed: June 24, 2008
    Publication date: December 25, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masakatsu TAKASHITA, Yasuto SUMI, Masaru IZUMISAWA, Hiroshi OHTA, Wataru SAITO, Syotaro ONO
  • Publication number: 20080290403
    Abstract: A semiconductor apparatus includes a first semiconductor layer, a second semiconductor layer provided on a major surface of the first semiconductor layer, a third semiconductor layer provided on the major surface and being adjacent to the second semiconductor layer, a termination semiconductor layer provided on the major surface of the first semiconductor layer in a termination region outside the device region, a channel stop layer, and a channel stop electrode. The channel stop layer is provided in contact with the termination semiconductor layer on the major surface of the first semiconductor layer in an outermost peripheral portion outside the termination semiconductor layer and has a higher impurity concentration than the termination semiconductor layer. The channel stop electrode is provided on at least part of a surface of the channel stop layer and projects toward the termination semiconductor layer beyond at least a superficial portion of the channel stop layer.
    Type: Application
    Filed: May 19, 2008
    Publication date: November 27, 2008
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Syotaro ONO, Wataru Saito, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta, Wataru Sekine
  • Publication number: 20080246079
    Abstract: A power semiconductor device includes: a first semiconductor layer; a second semiconductor layer and a third semiconductor layer provided in an upper portion of the first semiconductor layer and alternately arranged parallel to an upper surface of the first semiconductor layer; a plurality of fourth semiconductor layers provided on the third semiconductor layer; a fifth semiconductor layer selectively formed in an upper surface of each of the fourth semiconductor layers; a control electrode; a gate insulating film; a first main electrode provided on a lower surface of the first semiconductor layer; and a second main electrode provided on the fourth and the fifth semiconductor layers.
    Type: Application
    Filed: March 18, 2008
    Publication date: October 9, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Wataru Saito, Syotaro Ono, Masakatsu Takashita, Yauto Sumi, Masaru Izumisawa, Wataru Sekine, Hiroshi Ohta, Shoichiro Kurushima
  • Publication number: 20080135929
    Abstract: A power semiconductor device includes: a semiconductor substrate; a gate insulating film; a control electrode insulated from the semiconductor substrate by the gate insulating film; a first main electrode provided on a lower surface side of the semiconductor substrate; and a second main electrode provided on an upper surface side of the semiconductor substrate.
    Type: Application
    Filed: November 1, 2007
    Publication date: June 12, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Wataru SAITO, Syotaro Ono, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta
  • Publication number: 20080135926
    Abstract: A semiconductor device includes: a drift layer having a superjunction structure; a semiconductor base layer selectively formed in a part of one surface of the drift layer; a first RESURF layer formed around a region having the semiconductor base layer formed thereon; a second semiconductor RESURF layer of a conductivity type which is opposite to a conductivity type of the first semiconductor RESURF layer; a first main electrode connected to a first surface of the drift layer; and a second main electrode connected to a second surface of the drift layer. The first RESURF layer is connected to the semiconductor base layer. The second semiconductor RESURF layer is in contact with the first semiconductor RESURF layer.
    Type: Application
    Filed: November 7, 2007
    Publication date: June 12, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Syotaro Ono, Wataru Saito, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta
  • Publication number: 20070272979
    Abstract: A semiconductor device includes: a semiconductor layer of a first conductivity type; a first semiconductor pillar region of the first conductivity type provided on a major surface of the semiconductor layer; a second semiconductor pillar region of a second conductivity type provided adjacent to the first semiconductor pillar region on the major surface of the semiconductor layer, the second semiconductor pillar region forming a periodic arrangement structure substantially parallel to the major surface of the semiconductor layer together with the first semiconductor pillar region; a first main electrode; a first semiconductor region of the second conductivity type; a second semiconductor region of the first conductivity type; a second main electrode; a control electrode; and a high-resistance semiconductor layer provided on the semiconductor layer in an edge termination section surrounding the first semiconductor pillar region and the second semiconductor pillar region.
    Type: Application
    Filed: May 15, 2007
    Publication date: November 29, 2007
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Wataru SAITO, Syotaro Ono, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta, Wataru Sekine
  • Publication number: 20070272977
    Abstract: A power semiconductor device includes: a first semiconductor layer of a first conductivity type; a second semiconductor layer of the first conductivity type and a third semiconductor layer of a second conductivity type formed on the first semiconductor layer and alternately arranged along at least one direction parallel to a surface of the first semiconductor layer; a first main electrode; a fourth semiconductor layer of the second conductivity type selectively formed in a surface of the second semiconductor layer and a surface of the third semiconductor layer; a fifth semiconductor layer of the first conductivity type selectively formed in a surface of the fourth semiconductor layer; a second main electrode; and a control electrode. At least one of the second and the third semiconductor layers has a dopant concentration profile along the one direction, the dopant concentration profile having a local minimum at a position except both ends thereof.
    Type: Application
    Filed: March 1, 2007
    Publication date: November 29, 2007
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Wataru Saito, Syotaro Ono, Masakatsu Takashita, Yasuto Sumi, Masaru Izumisawa, Hiroshi Ohta
  • Publication number: 20070267664
    Abstract: A semiconductor device according to the present invention comprises a first semiconductor layer of the first conductivity type. A pillar layer includes first semiconductor pillars of the first conductivity type and second semiconductor pillars of the second conductivity type arranged periodically and alternately on the first semiconductor layer. The first and second semiconductor pillar layer have a cross section in the shape of stripes in a planar direction. There is a semiconductor base layer of the second conductivity type selectively formed in a surface of the second semiconductor pillar, and a semiconductor diffusion layer of the first conductivity type selectively formed in a surface of the semiconductor base layer. The longitudinal direction of the shape of stripes is made almost same as the direction of pattern shift caused in the first semiconductor layer.
    Type: Application
    Filed: May 21, 2007
    Publication date: November 22, 2007
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yasuto SUMI, Masakatsu Takashita, Masaru Izumisawa, Hiroshi Ohta, Wataru Saito, Syotaro Ono