Patents by Inventor Makoto Koshimizu

Makoto Koshimizu 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: 9349827
    Abstract: In an IGBT, defects generated by ion implantation for introduction of the P-type collector region or N-type buffer region into the N?-type drift region near the N-type buffer region remain to improve the switching speed, however the leak current increases by bringing a depletion layer into contact with the crystal defects at the off time. To avoid this, an IGBT is provided which includes an N-type buffer region having a higher concentration than that of an N?-type drift region and being in contact with a P-type on its backside, and a defect remaining region provided near the boundary between the N-type buffer region and the N?-type drift region. The N?-type drift region located on the front surface side with respect to the defect remaining region is provided with an N-type field stopping region having a higher concentration than that of the N?-type drift region.
    Type: Grant
    Filed: May 21, 2015
    Date of Patent: May 24, 2016
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Hitoshi Matsuura, Makoto Koshimizu, Yoshito Nakazawa
  • Publication number: 20150255572
    Abstract: In an IGBT, defects generated by ion implantation for introduction of the P-type collector region or N-type buffer region into the N?-type drift region near the N-type buffer region remain to improve the switching speed, however the leak current increases by bringing a depletion layer into contact with the crystal defects at the off time. To avoid this, an IGBT is provided which includes an N-type buffer region having a higher concentration than that of an N?-type drift region and being in contact with a P-type on its backside, and a defect remaining region provided near the boundary between the N-type buffer region and the N?-type drift region. The N?-type drift region located on the front surface side with respect to the defect remaining region is provided with an N-type field stopping region having a higher concentration than that of the N?-type drift region.
    Type: Application
    Filed: May 21, 2015
    Publication date: September 10, 2015
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Hitoshi MATSUURA, Makoto KOSHIMIZU, Yoshito NAKAZAWA
  • Patent number: 9064839
    Abstract: In an IGBT, defects generated by ion implantation for introduction of the P-type collector region or N-type buffer region into the N?-type drift region near the N-type buffer region remain to improve the switching speed, however the leak current increases by bringing a depletion layer into contact with the crystal defects at the off time. To avoid this, an IGBT is provided which includes an N-type buffer region having a higher concentration than that of an N?-type drift region and being in contact with a P-type on its backside, and a defect remaining region provided near the boundary between the N-type buffer region and the N?-type drift region. The N?-type drift region located on the front surface side with respect to the defect remaining region is provided with an N-type field stopping region having a higher concentration than that of the N?-type drift region.
    Type: Grant
    Filed: May 14, 2012
    Date of Patent: June 23, 2015
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Hitoshi Matsuura, Makoto Koshimizu, Yoshito Nakazawa
  • Publication number: 20130087828
    Abstract: A terrace insulating film (SL) to be overridden by a gate electrode (G) of an nLDMOS device is configured by LOCOS, and a device isolation portion (SS) is configured by STI. Furthermore, on an outermost periphery of an active region where a plurality of nLDMOS devices are formed, a guard ring having the same potential as that of a drain region (D) is provided. And, via this guard ring, the device isolation portion (SS) is formed in a periphery of the active region, thereby not connecting but isolating the terrace insulating film (SL) and the device isolation portion (SS) from each other.
    Type: Application
    Filed: June 21, 2010
    Publication date: April 11, 2013
    Inventors: Makoto Koshimizu, Hideki Niwayama, Kazuyuki Umezu, Hiroki Soeda, Atsushi Tachigami, Takeshi Iijima
  • Publication number: 20120313139
    Abstract: In an IGBT, defects generated by ion implantation for introduction of the P-type collector region or N-type buffer region into the N?-type drift region near the N-type buffer region remain to improve the switching speed, however the leak current increases by bringing a depletion layer into contact with the crystal defects at the off time. To avoid this, an IGBT is provided which includes an N-type buffer region having a higher concentration than that of an N?-type drift region and being in contact with a P-type on its backside, and a defect remaining region provided near the boundary between the N-type buffer region and the N?-type drift region. The N?-type drift region located on the front surface side with respect to the defect remaining region is provided with an N-type field stopping region having a higher concentration than that of the N?-type drift region.
    Type: Application
    Filed: May 14, 2012
    Publication date: December 13, 2012
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Hitoshi MATSUURA, Makoto KOSHIMIZU, Yoshito NAKAZAWA
  • Publication number: 20070087501
    Abstract: A sidewall-insulation film 9 is provided on a side surface of a first opening portion 8a formed in a base extraction electrode 5B of a hetero-junction bipolar transistor, and a portion of the sidewall-insulation film 9 extends so as to protrude from a surface opposite to a semiconductor substrate 1 toward a main surface of the semiconductor substrate 1 in the base extraction electrode 5B, and protruded length thereof is set to be equal to or smaller than one half of thickness of the insulation film 4 interposed between the main surface of the semiconductor substrate 1 and a lower surface of the base extraction electrode 5B.
    Type: Application
    Filed: December 11, 2006
    Publication date: April 19, 2007
    Inventors: Makoto Koshimizu, Yasuaki Kagotoshi, Nobuo Machida
  • Patent number: 7151035
    Abstract: A sidewall-insulation film 9 is provided on a side surface of a first opening portion 8a formed in a base extraction electrode 5B of a hetero-junction bipolar transistor, and a portion of the sidewall-insulation film 9 extends so as to protrude from a surface opposite to a semiconductor substrate 1 toward a main surface of the semiconductor substrate 1 in the base extraction electrode 5B, and protruded length thereof is set to be equal to or smaller than one half of thickness of the insulation film 4 interposed between the main surface of the semiconductor substrate 1 and a lower surface of the base extraction electrode 5B.
    Type: Grant
    Filed: April 16, 2002
    Date of Patent: December 19, 2006
    Assignee: Renesas Technology Corp.
    Inventors: Makoto Koshimizu, Yasuaki Kagotoshi, Nobuo Machida
  • Publication number: 20050181569
    Abstract: A sidewall-insulation film 9 is provided on a side surface of a first opening portion 8a formed in a base extraction electrode 5B of a hetero-junction bipolar transistor, and a portion of the sidewall-insulation film 9 extends so as to protrude from a surface opposite to a semiconductor substrate 1 toward a main surface of the semiconductor substrate 1 in the base extraction electrode 5B, and protruded length thereof is set to be equal to or smaller than one half of thickness of the insulation film 4 interposed between the main surface of the semiconductor substrate 1 and a lower surface of the base extraction electrode 5B.
    Type: Application
    Filed: April 16, 2002
    Publication date: August 18, 2005
    Inventors: Makoto Koshimizu, Yasuaki Kagotoshi, Nobuo Machida