Patents by Inventor Shinsuke Harada

Shinsuke Harada 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: 20150171169
    Abstract: In the present invention, a p-type pillar layer constituting a super junction is formed separately into an upper layer in contact with a base layer and an underlying lower layer. The upper layer has a higher impurity concentration than the lower layer. An interface between the upper layer and the lower layer of the pillar layer and a contact point between the interface and a drift layer are located below the bottom of a trench groove. This allows depletion in an upper portion of an n-type pillar to occur at a lower voltage than in a lower portion thereof in the blocking state. Thus, the application of an electric field to an oxide film can be suppressed without sacrificing the other characteristics, and the device is successfully prevented from being broken.
    Type: Application
    Filed: April 23, 2013
    Publication date: June 18, 2015
    Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventor: Shinsuke Harada
  • Publication number: 20150108501
    Abstract: In an active region, p+ regions are selectively disposed in a surface layer of an n? drift layer on an n+ semiconductor substrate. A p-base layer is disposed on surfaces of the n? drift layer and the P+ regions, and an MOS structure is disposed on the p-base layer. In another portion of the active region, a p+ region is disposed to be in contact with the source electrode on the p+ regions. In a breakdown voltage structure region (100), a JTE structure having at least a P? region is disposed separately from the P+ regions and the p-base layer, to surround the active region. The P? region is electrically in contact with the P+ region in a portion in which the MOS structure is not formed, in the vicinity of the boundary between the active region and the breakdown voltage structure region.
    Type: Application
    Filed: March 18, 2013
    Publication date: April 23, 2015
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Noriyuki Iwamuro, Yasuyuki Hoshi, Yuichi Harada, Shinsuke Harada
  • Publication number: 20150102363
    Abstract: A silicon carbide semiconductor device has a first-conductivity-type semiconductor layer having a lower impurity concentration and formed on a first-conductivity-type semiconductor substrate, a second-conductivity-type semiconductor layer having a higher impurity concentration and selectively formed in the first-conductivity-type semiconductor layer, a second-conductivity-type base layer having a lower impurity concentration formed on a surface of the second-conductivity-type semiconductor layer, a first-conductivity-type source region selectively formed in a surface layer of the base layer, a first-conductivity-type well region formed to penetrate the base layer from a surface to the first-conductivity-type semiconductor layer, and a gate electrode formed via a gate insulation film on a surface of the base layer interposed between the source region and the well region.
    Type: Application
    Filed: March 18, 2013
    Publication date: April 16, 2015
    Applicants: NATIONAL INSTIUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, FUJI ELECTRIC CO., LTD.
    Inventors: Atsushi Tanaka, Noriyuki Iwamuro, Shinsuke Harada
  • Publication number: 20150076521
    Abstract: To provide a vertical SIC-MOSFET and IGBT capable of having low ON-resistance without destruction of gate oxide films or degradation of reliability even when a high voltage is applied, and a fabrication method thereof, a vertical mosfet has a semiconductor layer and a base layer joined instead of a well region 6 so as to include, as a joining portion, a point that is farthest and equidistant from centers of all the source regions facing each other and that is closest and equidistant from end portions farthest from the centers of the source regions in a planar view.
    Type: Application
    Filed: March 14, 2013
    Publication date: March 19, 2015
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Atsushi Tanaka, Noriyuki Iwamuro, Shinsuke Harada
  • Publication number: 20150076519
    Abstract: A silicon carbide vertical MOSFET includes an N-counter layer of a first conductivity type formed in a surface layer other than a second semiconductor layer base layer selectively formed in a low concentration layer on a surface of the substrate, a gate electrode layer formed through a gate insulating film in at least a portion of an exposed portion of a surface of a third semiconductor layer of a second conductivity type between a source region of the first conductivity type and the N-counter layer of the first conductivity type, and a source electrode in contact commonly with surfaces of the source region and the third semiconductor layer. Portions of the second conductivity type semiconductor layer are connected with each other in a region beneath the N-counter layer.
    Type: Application
    Filed: March 29, 2013
    Publication date: March 19, 2015
    Applicants: FUJI ELECTRIC CO., LTD., NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Noriyuki Iwamuro, Shinsuke Harada, Yasuyuki Hoshi, Yuichi Harada
  • Publication number: 20150069415
    Abstract: An n-type SiC layer is formed on a front face of an n+-type SiC substrate and plural p-type regions are selectively formed inside the n-type SiC layer. A p-type SiC layer is formed covering the surfaces of the n-type SiC layer and the p-type regions. An n-type region is formed inside the p-type SiC layer to be connected to the n-type SiC layer. An n+-type source region and a p+-type contact region are formed inside the p-type SiC layer, positioned away from the n-type region and in contact with each other. The n-type region in the p-type SiC layer is formed such that the width LJFET of the n-type region is within a range from 0.8 ?m to 3.0 ?m and the impurity concentration of the n-type region is greater than 1.0×1016 cm?3 and less than or equal to 5.0×1016 cm?3.
    Type: Application
    Filed: March 18, 2013
    Publication date: March 12, 2015
    Applicants: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, FUJI ELECTRIC CO., LTD.
    Inventors: Shinsuke Harada, Noriyuki Iwamuro, Yasuyuki Hoshi, Yuichi Harada
  • Publication number: 20150053998
    Abstract: A base layer is used that has an N-type SiC layer formed in a surface layer on the front surface side of an N-type SiC substrate, and a P-type region is formed on a surface of the N-type SiC layer with an N-type source region selectively formed in a surface layer of the P-type region. A source electrode is formed on a surface of the N-type source region and a drain electrode is formed on the back surface side of the N-type SiC substrate. Additionally, the gate electrode is formed via a gate insulation film only on a surface of the P-type region. In this way, high electric field is no longer applied to the gate insulation film on the surface of the N-type SiC layer due to stoppage of voltage application to the gate electrode.
    Type: Application
    Filed: March 18, 2013
    Publication date: February 26, 2015
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yuichi Harada, Noriyuki Iwamuro, Yasuyuki Hoshi, Shinsuke Harada
  • Patent number: 8952391
    Abstract: A silicon carbide vertical MOSFET having low ON-resistance and high blocking voltage. A first deposition film of low concentration silicon carbide of a first conductivity type is formed on the surface of a high concentration silicon carbide substrate of a first conductivity type. Formed on the first deposition film is a second deposition film that includes a high concentration gate region of a second conductivity type, with a first region removed selectively. A third deposition film is formed on the second deposition film, which includes a second region that is wider than the selectively removed first region, a high concentration source region of a first conductivity type, and a low concentration gate region of a second conductivity type. A low concentration base region of a first conductivity type is formed in contact with the first deposition film in the first and second regions.
    Type: Grant
    Filed: October 3, 2003
    Date of Patent: February 10, 2015
    Assignees: National Institute of Advanced Industrial Science and Technology, Sanyo Electric Co., Ltd.
    Inventors: Shinsuke Harada, Tsutomu Yatsuo, Kenji Fukuda, Mitsuo Okamoto, Kazuhiro Adachi, Seiji Suzuki
  • Publication number: 20140113421
    Abstract: A silicon carbide vertical MOSFET having low ON-resistance and high blocking voltage is provided. For this, a first deposition film (2) of low concentration silicon carbide of a first conductivity type is formed on the surface of a high concentration silicon carbide substrate (1) of a first conductivity type. Formed on the first deposition film (2) is a second deposition film (31) that comprises a high concentration gate region of a second conductivity type, with a first region removed selectively. A third deposition film (32) formed on the second deposition film, which comprises a second region that is wider than the selectively removed first region, a high concentration source region (5) of a first conductivity type and a low concentration gate region (11) of a second conductivity type. A low concentration base region (4) of a first conductivity type is formed in contact with the first deposition film (2) in the first and second regions.
    Type: Application
    Filed: December 31, 2013
    Publication date: April 24, 2014
    Applicants: SANYO ELECTRIC CO., LTD., NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Shinsuke HARADA, Tsutomu Yatsuo, Kenji Fukuda, Mitsuo Okamoto, Kazuhiro Adachi, Seiji Suzuki
  • Publication number: 20140040462
    Abstract: A device management system manages an electronic device and a lighting device via a network and includes an acquiring section configured to acquire, from the first device, first operating history information relating to an operating history of the first device and acquire, from a monitor connected to the second device, second operating history information relating to an operating history of the second device, the second operating history information being of a type different from that of the first operating history information; a first generating section configured to generate first management information based on the first operating history information; and a second generating section configured to generate second management information of a type identical to that of the first management information based on the second operating history information.
    Type: Application
    Filed: August 2, 2013
    Publication date: February 6, 2014
    Applicant: RICOH COMPANY, LIMITED
    Inventor: Shinsuke Harada
  • Publication number: 20140008666
    Abstract: A silicon carbide vertical field effect transistor includes a first-conductive-type silicon carbide substrate; a low-concentration first-conductive-type silicon carbide layer formed on a surface of the first-conductive-type silicon carbide substrate; second-conductive-type regions selectively formed on a surface of the first-conductive-type silicon carbide layer; first-conductive-type source regions formed in the second-conductive-type regions; a high-concentration second-conductive-type region formed between the first-conductive-type source regions in the second-conductive-type region; a source electrode electrically connected to the high-concentration second-conductive-type region and a first-conductive-type source region; a gate insulating film formed from the first-conductive-type source regions formed in adjacent second-conductive-type regions, onto the second-conductive-type regions and the first-conductive-type silicon carbide layer; a gate electrode formed on the gate insulating film; and a drain elec
    Type: Application
    Filed: April 6, 2012
    Publication date: January 9, 2014
    Applicants: National Instituteof Advanced Industrial Science and Technology, FUJI ELECTRIC CO., LTD.
    Inventors: Yuichi Harada, Shinsuke Harada, Yasuyuki Hoshi, Noriyuki Iwamuro
  • Patent number: 8003991
    Abstract: This invention has a cell incorporating a built-in Schottky diode region disposed in at least part of an elementary cell that constitutes an SiC vertical MOSFET provided in a low-density p-type deposit film with a channel region and a base region inverted to an n-type by ion implantation. This built-in Schottky diode region has built therein a Schottky diode of low on-resistance that is formed of a second deficient pan disposed in a high-density gate layer, a second n-type base layer penetrating a low-density p-type deposit layer formed thereon, reaching an n-type drift layer of the second deficient part and attaining its own formation in consequence of inversion of the p-type deposit layer into an n-type by the ion implantation of an n-type impurity from the surface, and a source electrode connected in the manner of forming a Schottky barrier to the surface-exposed part of the second n-type base layer.
    Type: Grant
    Filed: December 27, 2006
    Date of Patent: August 23, 2011
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Tsutomu Yatsuo, Shinsuke Harada, Kenji Fukuda, Mitsuo Okamoto
  • Publication number: 20110121316
    Abstract: The area of each body region is minimized, and the gate oxide films at the bottoms of the trenches are more effectively protected by depletion layers extending from the body regions. According to the present invention, an n?-type drift layer and a p-type base region are stacked on an n+-type silicon carbide substrate, and an n+-type source region is formed in a predetermined region of a surface portion in the base region. A gate trench is formed in a trench groove that reaches the drift layer. A p-type body region is formed at a deeper location than the gate trench. The p-type body region is adjacent to the gate trench but is not in contact with the gate trench. When viewed from above, the gate trench having a hexagonal shape surrounds the p-type body region. The side faces of the gate trench are formed only by {11-20} planes of silicon carbide.
    Type: Application
    Filed: October 29, 2010
    Publication date: May 26, 2011
    Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventor: Shinsuke Harada
  • Patent number: 7935628
    Abstract: A low on-resistance silicon carbide semiconductor device is provided to include an ohmic electrode of low contact resistance and high adhesion strength formed on a lower surface of silicon carbide. Specifically, the silicon carbide semiconductor device includes at least an insulating film, formed on an upper surface of a silicon carbide substrate, and includes at least an ohmic electrode, formed of an alloy comprising nickel and titanium, or formed of a silicide comprising nickel and titanium, and which is formed on the lower surface of the silicon carbide substrate.
    Type: Grant
    Filed: August 1, 2007
    Date of Patent: May 3, 2011
    Assignee: National Institute for Advanced Industrial Science and Technology
    Inventors: Shinsuke Harada, Makoto Katou, Kenji Fukuda, Tsutomu Yatsuo
  • Patent number: 7880173
    Abstract: A semiconductor device and a method of manufacturing the device using a (000-1)-faced silicon carbide substrate are provided. A SiC semiconductor device having a high blocking voltage and high channel mobility is manufactured by optimizing the heat-treatment method used following the gate oxidation. The method of manufacturing a semiconductor device includes the steps of forming a gate insulation layer on a semiconductor region formed of silicon carbide having a (000-1) face orientation, forming a gate electrode on the gate insulation layer, forming an electrode on the semiconductor region, cleaning the semiconductor region surface. The gate insulation layer is formed in an atmosphere containing 1% or more H2O (water) vapor at a temperature of from 800° C. to 1150° C. to reduce the interface trap density of the interface between the gate insulation layer and the semiconductor region.
    Type: Grant
    Filed: February 4, 2008
    Date of Patent: February 1, 2011
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Kenji Fukuda, Junji Senzaki, Shinsuke Harada, Makoto Kato, Tsutomu Yatsuo, Mitsuo Okamoto
  • Patent number: 7811874
    Abstract: The object is to provide a method for the fabrication of a semiconductor device having undergone an anneal treatment for the purpose of forming such ohmic contact as enables decrease of ohmic contact resistance and being provided on the (000-1) plane of silicon carbide with an insulating film and provide the semiconductor device. The method for the fabrication of a silicon carbide semiconductor device includes the steps of performing thermal oxidation on the (000-1) plane of a silicon carbide semiconductor in a gas containing at least oxygen and moisture, thereby forming an insulating film in such a manner as to contact the (000-1) plane of the silicon carbide semiconductor, removing part of the insulating film, thereby forming an opening part therein, depositing contact metal on at least part of the opening part, and performing a heat treatment, thereby forming a reaction layer of the contact metal and silicon carbide, wherein the heat treatment is implemented in a mixed gas of an inert gas and hydrogen.
    Type: Grant
    Filed: January 16, 2007
    Date of Patent: October 12, 2010
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Shinsuke Harada, Makoto Katou, Kenji Fukuda, Tsutomu Yatsuo
  • Patent number: 7728336
    Abstract: In an SiC vertical MOSFET comprising a channel region and an n-type inverted electron guide path formed through ion implantation in a low-concentration p-type deposition film, the width of the channel region may be partly narrowed owing to implantation mask positioning failure, and the withstand voltage of the device may lower, and therefore, the device could hardly satisfy both low on-resistance and high withstand voltage. In the invention, second inverted layers (41, 42) are provided at the same distance on the right and left sides from the inverted layer (40) to be the electron guide path in the device, and the inverted layers are formed through simultaneous ion implantation using the same mask, and accordingly, the length of all the channel regions in the device is made uniform, thereby solving the problem.
    Type: Grant
    Filed: September 13, 2007
    Date of Patent: June 1, 2010
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Tsutomu Yatsuo, Shinsuke Harada, Mitsuo Okamoto, Kenji Fukuda, Makoto Kato
  • Publication number: 20100012951
    Abstract: In an SiC vertical MOSFET comprising a channel region and an n-type inverted electron guide path formed through ion implantation in a low-concentration p-type deposition film, the width of the channel region may be partly narrowed owing to implantation mask positioning failure, and the withstand voltage of the device may lower, and therefore, the device could hardly satisfy both low on-resistance and high withstand voltage. In the invention, second inverted layers (41, 42) are provided at the same distance on the right and left sides from the inverted layer (40) to be the electron guide path in the device, and the inverted layers are formed through simultaneous ion implantation using the same mask, and accordingly, the length of all the channel regions in the device is made uniform, thereby solving the problem.
    Type: Application
    Filed: September 13, 2007
    Publication date: January 21, 2010
    Inventors: Tsutomu Yatsuo, Shinsuke Harada, Mitsuo Okamoto, Kenji Fukuda, Makoto Kato
  • Publication number: 20090321746
    Abstract: A low on-resistance silicon carbide semiconductor device is provided that includes an ohmic electrode of low contact resistance and high adhesion strength formed on a lower surface of silicon carbide. The silicon carbide semiconductor device includes: at least an insulating film 7, formed on an upper surface of silicon carbide; and at least an ohmic electrode 12, formed of an alloy comprising nickel and titanium, or a silicide comprising nickel and titanium, and which is formed on the lower surface of the silicon carbide.
    Type: Application
    Filed: August 1, 2007
    Publication date: December 31, 2009
    Inventors: Shinsuke Harada, Makoto Katou, Kenji Fukuda, Tsutomu Yatsuo
  • Publication number: 20090173949
    Abstract: This invention has a cell incorporating a built-in Schottky diode region disposed in at least part of an elementary cell that constitutes an SiC vertical MOSFET provided in a low-density p-type deposit film with a channel region and a base region inverted to an n-type by ion implantation. This built-in Schottky diode region has built therein a Schottky diode of low on-resistance that is formed of a second deficient pan disposed in a high-density gate layer, a second n-type base layer penetrating a low-density p-type deposit layer formed thereon, reaching an n-type drift layer of the second deficient part and attaining its own formation in consequence of inversion of the p-type deposit layer into an n-type by the ion implantation of an n-type impurity from the surface, and a source electrode connected in the manner of forming a Schottky barrier to the surface-exposed part of the second n-type base layer.
    Type: Application
    Filed: December 27, 2006
    Publication date: July 9, 2009
    Applicant: National Institute of Adv. Industrial Sci. & Tech.
    Inventors: Tsutomu Yatsuo, Shinsuke Harada, Kenji Fukuda, Mitsuo Okamoto