Patents by Inventor Keiichiro Numakura

Keiichiro Numakura 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: 11973108
    Abstract: A semiconductor device includes: a drift region that is arranged on a main surface of a substrate, and has a higher impurity concentration than the substrate; a first well region that is connected to the drift region; and a second well region that is arranged adjacent to the first well region and faces the drift region. The second well region has a higher impurity concentration than the first well region. A distance between the source region that faces the drift region via the first well region and the drift region is greater than a distance between the second well region and the drift region, in a direction parallel to the main surface of the substrate. A depletion layer extending from the second well region reaches the drift region.
    Type: Grant
    Filed: December 1, 2020
    Date of Patent: April 30, 2024
    Assignees: NISSAN MOTOR CO., LTD., RENAULT S.A.S.
    Inventors: Wei Ni, Tetsuya Hayashi, Keiichiro Numakura, Toshiharu Marui, Ryouta Tanaka, Yuichi Iwasaki
  • Patent number: 11916469
    Abstract: A resonant power conversion device includes: a main circuit provided with a semiconductor switch, a capacitor and an inductor connected in series or parallel to the semiconductor switch; and a drive circuit configured to drive the switching element. The switching element enters an off-state or an on-state depending on a control voltage input to a gate terminal, and the drive circuit includes two or more types of control voltages, as a control voltage at which the switching element enters an off-state.
    Type: Grant
    Filed: November 6, 2020
    Date of Patent: February 27, 2024
    Assignees: Nissan Motor Co., Ltd., RENAULT S.A.S.
    Inventors: Taku Shimomura, Keiichiro Numakura, Akinori Okubo
  • Publication number: 20240055475
    Abstract: A semiconductor device includes: a drift region that is arranged on a main surface of a substrate, and has a higher impurity concentration than the substrate; a first well region that is connected to the drift region; and a second well region that is arranged adjacent to the first well region and faces the drift region. The second well region has a higher impurity concentration than the first well region. A distance between the source region that faces the drift region via the first well region and the drift region is greater than a distance between the second well region and the drift region, in a direction parallel to the main surface of the substrate. A depletion layer extending from the second well region reaches the drift region.
    Type: Application
    Filed: December 1, 2020
    Publication date: February 15, 2024
    Applicants: NISSAN MOTOR CO., LTD., RENAULT s.a.s.
    Inventors: Wei NI, Tetsuya HAYASHI, Keiichiro NUMAKURA, Toshiharu MARUI, Ryouta TANAKA, Yuichi IWASAKI
  • Patent number: 11881526
    Abstract: A semiconductor device includes: a substrate; a source region formed on a main surface of the substrate; a well region electrically connected to the source region; a drift region in contact with the well region; a drain region in contact with the drift region; a first electrode electrically connected to the source region; a second electrode electrically connected to the drain region; a third electrode formed in contact with the source region, the well region, and the drift region through an insulating film; and a parasitic capacitance reduction region formed in contact with the source region and in contact with the third electrode through the insulating film and having a higher resistance value than that of the source region.
    Type: Grant
    Filed: November 9, 2020
    Date of Patent: January 23, 2024
    Assignees: Nissan Motor Co., Ltd., RENAULT S.A.S.
    Inventors: Toshiharu Marui, Tetsuya Hayashi, Keiichiro Numakura, Wei Ni, Ryota Tanaka, Yuichi Iwasaki
  • Publication number: 20230411516
    Abstract: A semiconductor device includes: a substrate; a source region formed on a main surface of the substrate; a well region electrically connected to the source region; a drift region in contact with the well region; a drain region in contact with the drift region; a first electrode electrically connected to the source region; a second electrode electrically connected to the drain region; a third electrode formed in contact with the source region, the well region, and the drift region through an insulating film; and a parasitic capacitance reduction region formed in contact with the source region and in contact with the third electrode through the insulating film and having a higher resistance value than that of the source region.
    Type: Application
    Filed: November 9, 2020
    Publication date: December 21, 2023
    Applicants: Nissan Motor Co., Ltd., RENAULT S.A.S.
    Inventors: Toshiharu Marui, Tetsuya Hayashi, Keiichiro Numakura, Wei Ni, Ryota Tanaka, Yuichi Iwasaki
  • Publication number: 20230412062
    Abstract: A resonant power conversion device includes: a main circuit provided with a semiconductor switch, a capacitor and an inductor connected in series or parallel to the semiconductor switch; and a drive circuit configured to drive the switching element. The switching element enters an off-state or an on-state depending on a control voltage input to a gate terminal, and the drive circuit includes two or more types of control voltages, as a control voltage at which the switching element enters an off-state.
    Type: Application
    Filed: November 6, 2020
    Publication date: December 21, 2023
    Applicants: Nissan Motor Co., Ltd., RENAULT S.A.S.
    Inventors: Taku Shimomura, Keiichiro Numakura, Akinori Okubo
  • Patent number: 11756994
    Abstract: A semiconductor device includes a semiconductor base body, and a first main electrode and a second main electrode provided on the semiconductor base body. The semiconductor base body includes a drift region of a first conductivity type through which a main current flows, a column region of a second conductivity type arranged adjacent to the drift region in parallel to a current passage of the main current, a second electrode-connection region of the first conductivity type electrically connected to the second main electrode, and a low-density electric-field relaxation region of the first conductivity type having a lower impurity concentration than the drift region and arranged between the second electrode-connection region and the column region.
    Type: Grant
    Filed: September 14, 2022
    Date of Patent: September 12, 2023
    Assignees: NISSAN MOTOR CO., LTD., RENAULT S.A.S.
    Inventors: Toshiharu Marui, Tetsuya Hayashi, Keiichiro Numakura, Wei Ni, Ryota Tanaka, Keisuke Takemoto
  • Publication number: 20230253512
    Abstract: A method for manufacturing a semiconductor device includes forming a trench on a first main surface of a conductive semiconductor substrate. The method includes laminating conductive layers, each of which is a first or a second conductive layer, along a surface normal direction of a side surface of the trench, while forming dielectric layers between a conductive layer closest to the side surface of the trench and the side surface of the trench, and between the corresponding conductive layers; and removing the first conductive layer and the dielectric layer, which are formed on a bottom portion of the trench, to electrically connect the second conductive layer to the semiconductor substrate at the bottom portion of the trench. After a portion of the first main surface, the portion being outside of the trench, is covered with an insulating protective film, the first conductive layer and the dielectric layer are removed.
    Type: Application
    Filed: April 17, 2023
    Publication date: August 10, 2023
    Applicants: NISSAN MOTOR CO., LTD., RENAULT S.A.S.
    Inventors: Toshiharu MARUI, Tetsuya HAYASHI, Keiichiro NUMAKURA, Wei NI, Ryota TANAKA
  • Patent number: 11664466
    Abstract: A semiconductor device includes: a conductive semiconductor substrate in which a trench is formed on the first main surface; a plurality of conductive layers, each of which is either a first conductive layer or a second conductive layer, which are laminated on one another along a surface normal direction of a side surface of the trench; and dielectric layers arranged between a conductive layer closest to the side surface of the trench among the plurality of conductive layers and the side surface of the trench, and between the plurality of corresponding conductive layers. The first conductive layer is electrically insulated from the semiconductor substrate, and the semiconductor substrate that electrically connects to the second conductive layer inside the trench electrically connects to the second electrode.
    Type: Grant
    Filed: August 1, 2018
    Date of Patent: May 30, 2023
    Assignees: NISSAN MOTOR CO., LTD., RENAULT S.A.S.
    Inventors: Toshiharu Marui, Tetsuya Hayashi, Keiichiro Numakura, Wei Ni, Ryota Tanaka
  • Publication number: 20230074093
    Abstract: A semiconductor device includes a semiconductor base body, and a first main electrode and a second main electrode provided on the semiconductor base body. The semiconductor base body includes a drift region of a first conductivity type through which a main current flows, a column region of a second conductivity type arranged adjacent to the drift region in parallel to a current passage of the main current, a second electrode-connection region of the first conductivity type electrically connected to the second main electrode, and a low-density electric-field relaxation region of the first conductivity type having a lower impurity concentration than the drift region and arranged between the second electrode-connection region and the column region.
    Type: Application
    Filed: September 14, 2022
    Publication date: March 9, 2023
    Applicants: NISSAN MOTOR CO., LTD., RENAULT s.a.s.
    Inventors: Toshiharu MARUI, Tetsuya HAYASHI, Keiichiro NUMAKURA, Wei NI, Ryota TANAKA, Keisuke TAKEMOTO
  • Publication number: 20230013819
    Abstract: A semiconductor device includes a semiconductor base body, and a first main electrode and a second main electrode provided on the semiconductor base body. The semiconductor base body includes a drift region of a first conductivity type through which a main current flows, a column region of a second conductivity type arranged adjacent to the drift region in parallel to a current passage of the main current, a second electrode-connection region of the first conductivity type electrically connected to the second main electrode, and a low-density electric-field relaxation region of the first conductivity type having a lower impurity concentration than the drift region and arranged between the second electrode-connection region and the column region.
    Type: Application
    Filed: September 14, 2022
    Publication date: January 19, 2023
    Applicants: NISSAN MOTOR CO., LTD., RENAULT s.a.s.
    Inventors: Toshiharu MARUI, Tetsuya HAYASHI, Keiichiro NUMAKURA, Wei NI, Ryota TANAKA, Keisuke TAKEMOTO
  • Patent number: 11557674
    Abstract: A semiconductor device includes: a substrate (10); a semiconductor layer (20) disposed on a main surface of this substrate (10); and a first main electrode (30) and a second main electrode (40), which are disposed on the substrate (10) separately from each other with the semiconductor layer (20) sandwiched therebetween and are individually end portions of a current path of a main current flowing in an on-state. The semiconductor layer (20) includes: a first conductivity-type drift region (21) through which a main current flows; a second conductivity-type column region (22) that is disposed inside the drift region (21) and extends in parallel to a current path; and an electric field relaxation region (23) that is disposed in at least a part between the drift region (21) and the column region (22) and is either a low-concentration region in which an impurity concentration is lower than in the same conductivity-type adjacent region or a non-doped region.
    Type: Grant
    Filed: July 27, 2018
    Date of Patent: January 17, 2023
    Assignees: NISSAN MOTOR CO., LTD., RENAULT s.a.s.
    Inventors: Toshiharu Marui, Tetsuya Hayashi, Keiichiro Numakura, Wei Ni, Ryota Tanaka, Keisuke Takemoto
  • Patent number: 11557647
    Abstract: A semiconductor device includes: a drift region of a first conductive type including a contact section and extension sections extending along the main surface of a substrate; column regions of a second conductive type which alternate with the extension sections in a perpendicular direction to the extension direction of the extension sections and each includes an end connecting to the contact section; a well region of a second conductive type which connects to the other end of each column region and tips of the extension sections; and electric field relaxing electrodes which are provided above at least some of residual pn junctions with an insulating film interposed therebetween. Herein, the residual pn junctions are pn junctions other than voltage holding pn junctions formed in interfaces between the extension sections and the column regions.
    Type: Grant
    Filed: April 19, 2018
    Date of Patent: January 17, 2023
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Toshiharu Marui, Tetsuya Hayashi, Keiichiro Numakura, Wei Ni, Ryota Tanaka, Keisuke Takemoto
  • Patent number: 11476326
    Abstract: A semiconductor device includes a semiconductor base body, and a first main electrode and a second main electrode provided on the semiconductor base body. The semiconductor base body includes a drift region of a first conductivity type through which a main current flows, a column region of a second conductivity type arranged adjacent to the drift region in parallel to a current passage of the main current, a second electrode-connection region of the first conductivity type electrically connected to the second main electrode, and a low-density electric-field relaxation region of the first conductivity type having a lower impurity concentration than the drift region and arranged between the second electrode-connection region and the column region.
    Type: Grant
    Filed: January 21, 2019
    Date of Patent: October 18, 2022
    Assignees: NISSAN MOTOR CO., LTD., RENAULT s.a.s.
    Inventors: Toshiharu Marui, Tetsuya Hayashi, Keiichiro Numakura, Wei Ni, Ryota Tanaka, Keisuke Takemoto
  • Publication number: 20220085157
    Abstract: A semiconductor device includes a semiconductor base body, and a first main electrode and a second main electrode provided on the semiconductor base body. The semiconductor base body includes a drift region of a first conductivity type through which a main current flows, a column region of a second conductivity type arranged adjacent to the drift region in parallel to a current passage of the main current, a second electrode-connection region of the first conductivity type electrically connected to the second main electrode, and a low-density electric-field relaxation region of the first conductivity type having a lower impurity concentration than the drift region and arranged between the second electrode-connection region and the column region.
    Type: Application
    Filed: January 21, 2019
    Publication date: March 17, 2022
    Applicants: NISSAN MOTOR CO., LTD., RENAULT s.a.s.
    Inventors: Toshiharu MARUI, Tetsuya HAYASHI, Keiichiro NUMAKURA, Wei NI, Ryota TANAKA, Keisuke TAKEMOTO
  • Patent number: 11251300
    Abstract: A semiconductor device includes: a substrate; a drift region disposed on a principal surface of the substrate; a first well region extending from a second principal surface of the drift region in a direction perpendicular to the second principal surface and having a bottom portion; a second well region being in contact with the bottom portion and disposed at a portion inside the substrate located below the bottom portion; and a source region extending in a perpendicular direction from a region of the second principal surface provided with the first well region, and reaching the second well region. In a direction parallel to the second principal surface and oriented from a source electrode to a drain electrode, a distance of the second well region in contact with a gate insulating film is shorter than a distance of the first well region in contact with the gate insulating film.
    Type: Grant
    Filed: April 19, 2018
    Date of Patent: February 15, 2022
    Assignees: NISSAN MOTOR CO., LTD., RENAULT S.A.S.
    Inventors: Wei Ni, Toshiharu Marui, Ryota Tanaka, Tetsuya Hayashi, Shigeharu Yamagami, Keiichiro Numakura, Keisuke Takemoto, Yasuaki Hayami
  • Publication number: 20210367070
    Abstract: A semiconductor device includes: a substrate having a groove formed on a main surface; a drift region of a first conductivity type, the drift region having a portion disposed at a bottom part; a well region of a second conductivity type, the well region being disposed in one sidewall to be connected to the drift region; a first semiconductor region of the first conductivity type, the first semiconductor region being disposed on a surface of the well region in the sidewall to be away from the drift region; a second semiconductor region of the first conductivity type, the second semiconductor region being disposed to be opposed to the well region via the drift region; and a gate electrode opposed to the well region, the gate electrode being disposed in a gate trench that has an opening extending over the upper surfaces of the well region and the first semiconductor region.
    Type: Application
    Filed: March 26, 2018
    Publication date: November 25, 2021
    Applicants: NISSAN MOTOR CO., LTD., RENAULT S.A.S.
    Inventors: Toshiharu MARUI, Tetsuya HAYASHI, Keiichiro NUMAKURA, Wei NI, Ryota TANAKA, Keisuke TAKEMOTO
  • Publication number: 20210313466
    Abstract: A semiconductor device includes: a substrate; a semiconductor layer disposed on a main surface of the substrate; and a first main electrode and a second main electrode, which are disposed on the substrate separately from each other with the semiconductor layer sandwiched therebetween and are individually end portions of a current path of a main current flowing in an on-state. The semiconductor layer includes: a first conductivity-type drift region through which a main current flows; a second conductivity-type column region that is disposed inside the drift region and extends in parallel to a current path; and an electric field relaxation region that is disposed in at least a part between the drift region and the column region and is either a low-concentration region in which an impurity concentration is lower than in the same conductivity-type adjacent region or a non-doped region.
    Type: Application
    Filed: July 27, 2018
    Publication date: October 7, 2021
    Applicants: NISSAN MOTOR CO., LTD., RENAULT S.A.S.
    Inventors: Toshiharu MARUI, Tetsuya HAYASHI, Keiichiro NUMAKURA, Wei NI, Ryota TANAKA, Keisuke TAKEMOTO
  • Publication number: 20210296308
    Abstract: A semiconductor device includes: a conductive semiconductor substrate in which a trench is formed on the first main surface; a plurality of conductive layers, each of which is either a first conductive layer or a second conductive layer, which are laminated on one another along a surface normal direction of a side surface of the trench; and dielectric layers arranged between a conductive layer closest to the side surface of the trench among the plurality of conductive layers and the side surface of the trench, and between the plurality of corresponding conductive layers. The first conductive layer is electrically insulated from the semiconductor substrate, and the semiconductor substrate that electrically connects to the second conductive layer inside the trench electrically connects to the second electrode.
    Type: Application
    Filed: August 1, 2018
    Publication date: September 23, 2021
    Applicants: NISSAN MOTOR CO., LTD., RENAULT S.A.S.
    Inventors: Toshiharu MARUI, Tetsuya HAYASHI, Keiichiro NUMAKURA, Wei NI, Ryota TANAKA
  • Publication number: 20210183726
    Abstract: There are included: a metal member having a groove formed on a front side surface thereof; a thermally conductive member provided in an inside of the groove and having a thermal conductivity in an X-axial direction on the front side surface higher than a thermal conductivity in a Y-axial direction orthogonal to the X-axial direction on the front side surface; and a semiconductor element provided on the front side surface of the metal member, and at least a part of which is in contact with the thermally conductive member.
    Type: Application
    Filed: October 27, 2017
    Publication date: June 17, 2021
    Applicant: NISSAN MOTOR CO., LTD.
    Inventors: Yosuke TOMITA, Tetsuya HAYASHI, Shigeharu YAMAGAMI, Keiichiro NUMAKURA, Yasuaki HAYAMI, Yuichi IWASAKI