Patents by Inventor Nao Nagata

Nao Nagata 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: 20240162353
    Abstract: A semiconductor device according to the present disclosure includes a semiconductor substrate having a first surface and a second surface opposite to the first surface, and a diode formed in the semiconductor substrate. The diode includes a drift layer of a first conductivity type on a side provided with the first surface, an anode layer of a second conductivity type opposite in conductivity type to the first conductivity type on the drift layer, and a trench. A bottom surface of the anode layer is located in a region deeper than a bottom surface of the trench with reference to the first surface.
    Type: Application
    Filed: October 13, 2023
    Publication date: May 16, 2024
    Inventor: Nao NAGATA
  • Publication number: 20240145586
    Abstract: An IGBT includes first and second trenches arranged side by side on a front surface of a semiconductor substrate, a collector region formed on a back surface side of the semiconductor substrate, a body region and an emitter region provided between the first and second trenches, a first trench gate electrode provided in the first trench, a second trench gate electrode provided in the second trench, a third trench gate electrode provided below the first trench gate electrode in the first trench, a fourth trench gate electrode provided below the second trench gate electrode in the second trench, and a floating region formed in the semiconductor substrate with the first and second trenches interposed therebetween.
    Type: Application
    Filed: September 20, 2023
    Publication date: May 2, 2024
    Inventor: Nao NAGATA
  • Publication number: 20230335590
    Abstract: A semiconductor device includes first and second active cell regions and an inactive cell region between the first and second active cell regions, wherein each of the first and second active cell regions comprises: a trench gate; a first trench emitter; a first hole barrier layer of a first conductivity type formed between the trench gate and the first trench emitter; a base layer of a second conductivity type formed on upper portion of the first hole barrier layer; an emitter layer of the first conductivity type formed on upper portion of the base layer; a latch-up prevention layer of the second conductivity type formed on upper portion of the first hole barrier layer, wherein the inactive cell region comprises: a second trench emitter; a first floating layer of the second conductivity type formed between the trench gate of the first active cell region and the second trench emitter.
    Type: Application
    Filed: April 14, 2022
    Publication date: October 19, 2023
    Inventor: Nao NAGATA
  • Patent number: 11776955
    Abstract: A semiconductor device includes a semiconductor substrate having first and second surfaces, an insulated gate bipolar transistor (IGBT) and a diode formed on the semiconductor substrate, wherein the diode comprises a drift layer of a first conductivity type formed so as to have a first region on the first surface of the semiconductor substrate, a first body layer of a second conductivity type formed so as to have a second region adjacent to the first region at an upper portion of the drift layer, a first floating layer of the second conductivity type formed so as to have a third region adjacent to the first region at an upper portion of the drift layer, a first trench electrode formed in a region adjacent to the first floating layer at an upper portion of the drift layer, and a first control gate formed on top of the first region.
    Type: Grant
    Filed: April 15, 2021
    Date of Patent: October 3, 2023
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Nao Nagata
  • Publication number: 20230155013
    Abstract: A semiconductor device includes a semiconductor substrate, a plurality of IGBTs (Insulated Gate Bipolar Transistors) formed on the semiconductor substrate), a gate electrode, a plurality of gate wires coupled to the gates of the IGBTs, and a gate resistor coupled to the gate electrode and the plurality of gate wires, wherein the gate resistor comprises a resistive element, a first contact that couples the gate electrode and the resistive element, and a plurality of second contacts each of which corresponds to each of the plurality of gate wires and couples to the resistive element and the corresponding gate wire, respectively, and wherein each of the plurality of second contacts is formed at a different distance from the first contact.
    Type: Application
    Filed: November 18, 2021
    Publication date: May 18, 2023
    Inventor: Nao NAGATA
  • Publication number: 20220336447
    Abstract: A semiconductor device includes a semiconductor substrate having first and second surfaces, an insulated gate bipolar transistor (IGBT) and a diode formed on the semiconductor substrate, wherein the diode comprises a drift layer of a first conductivity type formed so as to have a first region on the first surface of the semiconductor substrate, a first body layer of a second conductivity type formed so as to have a second region adjacent to the first region at an upper portion of the drift layer, a first floating layer of the second conductivity type formed so as to have a third region adjacent to the first region at an upper portion of the drift layer, a first trench electrode formed in a region adjacent to the first floating layer at an upper portion of the drift layer, and a first control gate formed on top of the first region.
    Type: Application
    Filed: April 15, 2021
    Publication date: October 20, 2022
    Inventor: Nao NAGATA
  • Patent number: 11444186
    Abstract: A semiconductor device includes a semiconductor substrate, first and second trench electrodes formed on the semiconductor substrate, a floating layer of a first conductivity type formed around the first and second trench electrodes, a floating separation layer of a second conductivity type formed between the first and second trench electrodes and contacted with the floating layer of the first conductivity type and a floating layer control gate disposed on the floating separation layer of the second conductivity type.
    Type: Grant
    Filed: October 28, 2020
    Date of Patent: September 13, 2022
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Nao Nagata
  • Patent number: 11342450
    Abstract: A semiconductor device having an IE-type IGBT structure comprises a stripe-shaped trench gate and a stripe-shaped trench emitter arranged to face the trench gate formed in a semiconductor substrate. The semiconductor device further comprises an N-type emitter layer and a P-type base layer both surrounded by the trench gate and the trench emitter formed in the semiconductor substrate. The semiconductor device also comprises a P-type base contact layer arranged on one side of the trench emitter and formed in the semiconductor substrate. The p-type base contact layer, the emitter layer, and the trench emitter are commonly connected with an emitter electrode. The trench emitter is formed deeper than the trench gate in a thickness direction of the semiconductor substrate.
    Type: Grant
    Filed: December 3, 2019
    Date of Patent: May 24, 2022
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Nao Nagata
  • Patent number: 11183589
    Abstract: To enhance the performance of a semiconductor device. Gate electrodes extending in a Y direction and applied with a gate potential, and emitter regions and base regions both applied with an emitter potential are formed in an active cell area. The plural emitter regions are formed so as to be separated from each other in the Y direction by the base regions. A plurality of hole discharge cell areas having a ring-shaped gate electrode applied with an emitter potential are formed within an inactive cell area. The hole discharge cell areas are arranged to be separated from each other along the Y direction. Thus, an input capacitance of an IGBT is reduced, and a switching loss at turn on of the IGBT is improved.
    Type: Grant
    Filed: April 27, 2020
    Date of Patent: November 23, 2021
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Nao Nagata
  • Patent number: 11183569
    Abstract: A semiconductor device and a method of manufacturing a semiconductor device capable of suppressing breakdown due to current concentration while suppressing an increase in chip size are provided. According to one embodiment, a semiconductor device has a gate resistance on a main surface side of a semiconductor substrate, a first contact and a second contact connected to an upper surface of the gate resistance, and a carrier discharging portion that discharges the carrier formed in the semiconductor substrate below the gate resistance, the gate resistance having a first contacting portion to which a first contact is connected, a second contacting portion to which a second contact is connected, and a plurality of extending portions with one end connected to the first contacting portion and the other end connected to the second contacting portion. The gate resistance forms an opening between adjacent extending portions and the carrier discharge portion is formed in the opening.
    Type: Grant
    Filed: October 17, 2019
    Date of Patent: November 23, 2021
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Nao Nagata
  • Publication number: 20210151588
    Abstract: A semiconductor device includes a semiconductor substrate, first and second trench electrodes formed on the semiconductor substrate, a floating layer of a first conductivity type formed around the first and second trench electrodes, a floating separation layer of a second conductivity type formed between the first and second trench. electrodes and contacted with. the floating layer of the first conductivity type and a floating layer control gate disposed on the floating separation layer of the second conductivity type.
    Type: Application
    Filed: October 28, 2020
    Publication date: May 20, 2021
    Inventor: Nao NAGATA
  • Patent number: 10998432
    Abstract: A semiconductor device including an IE-type trench gate IGBT requires to be improved in IE effect to reduce on voltage. The semiconductor device includes a trench gate electrode or a trench emitter electrode between an active cell region and an inactive cell region. The trench gate electrode and the trench emitter electrode are provided across the inactive cell region.
    Type: Grant
    Filed: November 4, 2019
    Date of Patent: May 4, 2021
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Nao Nagata
  • Patent number: 10937899
    Abstract: A semiconductor device include a semiconductor substrate, a first trench electrode formed in the semiconductor substrate and having a first portion, a second trench electrode formed in the semiconductor substrate having a second portion facing the first portion, a floating layer of a first conductivity type formed around the first and second trench electrodes, a drift layer of a second conductivity type connected to the floating layer of the first conductivity type and formed between the first and second trench electrodes, an impurity layer of the first conductivity type connected to the drift layer of the second conductivity type and formed between the first and second trench electrodes, and a floating layer control gate having a portion located at least above the impurity layer of the first conductivity type.
    Type: Grant
    Filed: February 7, 2020
    Date of Patent: March 2, 2021
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Nao Nagata
  • Patent number: 10930771
    Abstract: Performance of a semiconductor device is improved. An active cell region has a first gate electrode that extends in a Y direction and receives a gate potential, and a second gate electrode that extends in the Y direction and receives an emitter potential. A hybrid cell region including a p-type base region and an n-type emitter region is disposed in the active cell region. An n-type isolation region adjacent to the hybrid cell region in the Y direction is formed in the active cell region excluding the hybrid cell region. Hence, even if the p-type base region or a p-type floating region is formed in the active cell region excluding the hybrid cell region, such a p-type region is isolated from the base region in the hybrid cell region by the isolation region.
    Type: Grant
    Filed: October 8, 2018
    Date of Patent: February 23, 2021
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Nao Nagata
  • Publication number: 20200259005
    Abstract: To enhance the performance of a semiconductor device. Gate electrodes extending in a Y direction and applied with a gate potential, and emitter regions and base regions both applied with an emitter potential are formed in an active cell area. The plural emitter regions are formed so as to be separated from each other in the Y direction by the base regions. A plurality of hole discharge cell areas having a ring-shaped gate electrode applied with an emitter potential are formed within an inactive cell area. The hole discharge cell areas are arranged to be separated from each other along the Y direction. Thus, an input capacitance of an IGBT is reduced, and a switching loss at turn on of the IGBT is improved.
    Type: Application
    Filed: April 27, 2020
    Publication date: August 13, 2020
    Inventor: Nao NAGATA
  • Publication number: 20200212209
    Abstract: A semiconductor device having an IE-type IGBT structure is disclosed. Concretely, the semiconductor device comprises a stripe-shaped trench gate, a stripe-shaped trench emitter arranged to face the trench gate, an N-type emitter layer and a P-type base layer surrounded by the trench gate and the trench emitter, and a P-type base contact layer arranged on one side of the trench emitter, formed in a semiconductor substrate. The p-type base contact layer, the emitter layer, and the trench emitter are commonly connected with an emitter electrodes, and the trench emitter is formed deeper than the trench gate in a thickness direction of the semiconductor substrate.
    Type: Application
    Filed: December 3, 2019
    Publication date: July 2, 2020
    Inventor: Nao NAGATA
  • Publication number: 20200185500
    Abstract: A semiconductor device and a method of manufacturing a semiconductor device capable of suppressing breakdown due to current concentration while suppressing an increase in chip size are provided. According to one embodiment, a semiconductor device has a gate resistance on a main surface side of a semiconductor substrate, a first contact and a second contact connected to an upper surface of the gate resistance, and a carrier discharging portion that discharges the carrier formed in the semiconductor substrate below the gate resistance, the gate resistance having a first contacting portion to which a first contact is connected, a second contacting portion to which a second contact is connected, and a plurality of extending portions with one end connected to the first contacting portion and the other end connected to the second contacting portion. The gate resistance forms an opening between adjacent extending portions and the carrier discharge portion is formed in the opening.
    Type: Application
    Filed: October 17, 2019
    Publication date: June 11, 2020
    Inventor: Nao NAGATA
  • Patent number: 10672897
    Abstract: To enhance the performance of a semiconductor device. Gate electrodes extending in a Y direction and applied with a gate potential, and emitter regions and base regions both applied with an emitter potential are formed in an active cell area. The plural emitter regions are formed so as to be separated from each other in the Y direction by the base regions. A plurality of hole discharge cell areas having a ring-shaped gate electrode applied with an emitter potential are formed within an inactive cell area. The hole discharge cell areas are arranged to be separated from each other along the Y direction. Thus, an input capacitance of an IGBT is reduced, and a switching loss at turn on of the IGBT is improved.
    Type: Grant
    Filed: October 30, 2018
    Date of Patent: June 2, 2020
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Nao Nagata
  • Publication number: 20200066888
    Abstract: A semiconductor device including an IE-type trench gate IGBT requires to be improved in IE effect to reduce on voltage. The semiconductor device includes a trench gate electrode or a trench emitter electrode between an active cell region and an inactive cell region. The trench gate electrode and the trench emitter electrode are provided across the inactive cell region.
    Type: Application
    Filed: November 4, 2019
    Publication date: February 27, 2020
    Inventor: Nao NAGATA
  • Patent number: 10505029
    Abstract: A semiconductor device including an IE-type trench gate IGBT requires to be improved in IE effect to reduce on voltage. The semiconductor device includes a trench gate electrode or a trench emitter electrode between an active cell region and an inactive cell region. The trench gate electrode and the trench emitter electrode are provided across the inactive cell region.
    Type: Grant
    Filed: June 27, 2018
    Date of Patent: December 10, 2019
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Nao Nagata