Patents by Inventor Takashi Shiigi

Takashi Shiigi 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: 11749675
    Abstract: Between a source electrode (25) of a main device (24) and a current sensing electrode (22) of a current detection device (21), a resistor for detecting current is connected. Dielectric withstand voltage of gate insulator (36) is larger than a product of the resistor and maximal current flowing through the current detection device (21) with reverse bias. A diffusion length of a p-body region (32) of the main device (24) is shorter than that of a p-body (31) of the current detection device (21). A curvature radius at an end portion of the p-body region (32) of the main device (24) is smaller than that of the p-body (31) of the current detection device (21). As a result, at the inverse bias, electric field at the end portion of the p-body region (32) of the main device (24) becomes stronger than that of the p-body region (31) of the current detection device (21). Consequently, avalanche breakdown tends to occur earlier in the main device 24 than the current detection device (21).
    Type: Grant
    Filed: January 7, 2021
    Date of Patent: September 5, 2023
    Assignees: FUJI ELECTRIC CO., LTD., DENSO CORPORATION
    Inventors: Seiji Momota, Hitoshi Abe, Takashi Shiigi, Takeshi Fujii, Koh Yoshikawa, Tetsutaro Imagawa, Masaki Koyama, Makoto Asai
  • Publication number: 20230067428
    Abstract: Provided is a test method of a semiconductor device under test, the test method comprising: controlling the semiconductor device under test to an on state by inputting a control signal to the semiconductor device under test; and observing the semiconductor device under test at a time of controlling the semiconductor device under test in the on state to an off state and evaluating the semiconductor device under test, wherein the semiconductor device under test includes one semiconductor device under test or a plurality of semiconductor devices under test, and in the controlling to the on state, a length of an on-time for which the one semiconductor device under test or the plurality of semiconductor devices under test are set to the on state is adjusted based on a magnitude of a variation in a delay time of the control signal.
    Type: Application
    Filed: July 13, 2022
    Publication date: March 2, 2023
    Inventors: Kenichi ISHII, Atsushi YOSHIDA, Tomonori MORI, Takashi SHIIGI
  • Patent number: 11456359
    Abstract: A semiconductor device, including a substrate, and a deposit layer and a semiconductor layer formed sequentially on the substrate. The semiconductor layer has selectively disposed therein a first region, a second region and a contact region. A gate electrode is disposed on the first region and the semiconductor layer via a gate insulating film. A source electrode is formed in contact with the contact region and the second region. A drain electrode is disposed on the back surface of the substrate. The source electrode has a first titanium (Ti) film, and a titanium nitride (TiN) film, a second Ti film, and a metal film containing aluminum (Al) sequentially formed on the first Ti film. The source electrode may further include another TiN film, on which the first Ti film is formed.
    Type: Grant
    Filed: August 29, 2016
    Date of Patent: September 27, 2022
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki Hoshi, Yuichi Harada, Takashi Shiigi
  • Publication number: 20210134789
    Abstract: Between a source electrode (25) of a main device (24) and a current sensing electrode (22) of a current detection device (21), a resistor for detecting current is connected. Dielectric withstand voltage of gate insulator (36) is larger than a product of the resistor and maximal current flowing through the current detection device (21) with reverse bias. A diffusion length of a p-body region (32) of the main device (24) is shorter than that of a p-body (31) of the current detection device (21). A curvature radius at an end portion of the p-body region (32) of the main device (24) is smaller than that of the p-body (31) of the current detection device (21). As a result, at the inverse bias, electric field at the end portion of the p-body region (32) of the main device (24) becomes stronger than that of the p-body region (31) of the current detection device (21). Consequently, avalanche breakdown tends to occur earlier in the main device 24 than the current detection device (21).
    Type: Application
    Filed: January 7, 2021
    Publication date: May 6, 2021
    Applicants: FUJI ELECTRIC CO., LTD., DENSO CORPORATION
    Inventors: Seiji Momota, Hitoshi Abe, Takashi Shiigi, Takeshi Fujii, Koh Yoshikawa, Tetsutaro Imagawa, Masaki Koyama, Makoto Asai
  • Patent number: 10916541
    Abstract: Between a source electrode (25) of a main device (24) and a current sensing electrode (22) of a current detection device (21), a resistor for detecting current is connected. Dielectric withstand voltage of gate insulator (36) is larger than a product of the resistor and maximal current flowing through the current detection device (21) with reverse bias. A diffusion length of a p-body region (32) of the main device (24) is shorter than that of a p-body (31) of the current detection device (21). A curvature radius at an end portion of the p-body region (32) of the main device (24) is smaller than that of the p-body (31) of the current detection device (21). As a result, at the inverse bias, electric field at the end portion of the p-body region (32) of the main device (24) becomes stronger than that of the p-body region (31) of the current detection device (21). Consequently, avalanche breakdown tends to occur earlier in the main device 24 than the current detection device (21).
    Type: Grant
    Filed: September 2, 2016
    Date of Patent: February 9, 2021
    Assignees: FUJI ELECTRIC CO., LTD., DENSO CORPORATION
    Inventors: Seiji Momota, Hitoshi Abe, Takashi Shiigi, Takeshi Fujii, Koh Yoshikawa, Tetsutaro Imagawa, Masaki Koyama, Makoto Asai
  • Patent number: 10784256
    Abstract: A semiconductor device includes a plurality of semiconductor switching elements disposed on a single semiconductor substrate comprising a semiconductor having a bandgap that is wider than that of silicon; and a plurality of electrode pads that are disposed in a predetermined planar layout on a front surface of the semiconductor substrate, the plurality of electrode pads each being electrically connected to the plurality of semiconductor switching elements. A plurality of terminal pins to externally carry out voltage of the electrode pads is bonded through a plated film to all of the plurality of electrode pads by solder.
    Type: Grant
    Filed: September 30, 2016
    Date of Patent: September 22, 2020
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Takashi Shiigi, Shoji Yamada, Yuichi Harada, Yasuyuki Hoshi
  • Patent number: 10504785
    Abstract: A main semiconductor element and a temperature sensing part are arranged on a single silicon carbide base. The main semiconductor element is a vertical MOSFET and the temperature sensing part is a horizontal diode. An anode region of the temperature sensing part and an n+-type source region and a p+-type contact region of the main semiconductor element are connected by wiring by an anode electrode on a front surface of the silicon carbide base. The temperature sensing part, when the main semiconductor element is ON, is forward biased by drift current flowing in the main semiconductor element. The temperature sensing part, for example, is a poly-silicon diode constituted by a p-type poly-silicon layer and an n-type poly-silicon layer arranged on the front surface of the silicon carbide base. With such configuration, a semiconductor device having high reliability may be provided.
    Type: Grant
    Filed: May 25, 2018
    Date of Patent: December 10, 2019
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Shoji Yamada, Takashi Shiigi, Yasuyuki Hoshi
  • Patent number: 10497784
    Abstract: A current sensing part that detects overcurrent of a main semiconductor element is arranged on a same silicon carbide base as the main semiconductor element. An isolating part is arranged between the main semiconductor element and the current sensing part. The isolating part has a function of suppressing interference of the main semiconductor element and the current sensing part at the silicon carbide base. The isolating part is constituted by a trench provided a predetermined depth from a front surface of the silicon carbide base. An insulating film is provided in the trench, along inner walls of the trench. A poly-silicon layer is provided on the insulating film. With such a configuration, decreases in breakdown voltage of the current sensing part may be prevented.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: December 3, 2019
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki Hoshi, Takashi Shiigi, Shoji Yamada
  • Patent number: 10490625
    Abstract: A silicon carbide semiconductor device includes a silicon carbide semiconductor substrate, a first semiconductor layer, a first semiconductor region, a second semiconductor layer, a second semiconductor region, a third semiconductor region, a fourth semiconductor sub-region, a first electrode, a gate insulating film, a gate electrode, and second electrode. At a corner part of an active region in which a main current flows, a fifth semiconductor sub-region is provided. An impurity concentration of the fifth semiconductor sub-region is higher than an impurity concentration of the second semiconductor layer.
    Type: Grant
    Filed: March 30, 2018
    Date of Patent: November 26, 2019
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Shin'ichi Nakamata, Takashi Shiigi, Yasuyuki Hoshi, Yuichi Harada
  • Patent number: 10276666
    Abstract: On a front surface of an n+-type SiC substrate becoming a drain region, an n?-type drift layer, a p-type base layer, and an n+-type source layer are sequentially formed by epitaxial growth. In the n+-type source layer, the p+-type contact region is selectively provided. A trench is provided penetrating the n+-type source layer and the p-type base layer in the depth direction and reaching the n?-type drift layer. In the trench, a gate electrode is provided via a gate insulating film. A width between adjacent trenches is, for example, 1 ?m or less. A depth of the trench is, for example, 1 ?m or less. The width is narrow whereby substantially the entire p-type base layer forms a channel. A cell includes a FinFET structure in which one channel is sandwiched between MOS gates on both side. Thus, ON resistance may be reduced and decreased reliability may be prevented.
    Type: Grant
    Filed: August 30, 2017
    Date of Patent: April 30, 2019
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki Hoshi, Masahito Otsuki, Shoji Yamada, Takashi Shiigi
  • Publication number: 20180350900
    Abstract: A silicon carbide semiconductor device includes a silicon carbide semiconductor substrate, a first semiconductor layer, a first semiconductor region, a second semiconductor layer, a second semiconductor region, a third semiconductor region, a fourth semiconductor sub-region, a first electrode, a gate insulating film, a gate electrode, and second electrode. At a corner part of an active region in which a main current flows, a fifth semiconductor sub-region is provided. An impurity concentration of the fifth semiconductor sub-region is higher than an impurity concentration of the second semiconductor layer.
    Type: Application
    Filed: March 30, 2018
    Publication date: December 6, 2018
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Shin'ichi NAKAMATA, Takashi SHIIGI, Yasuyuki HOSHI, Yuichi HARADA
  • Patent number: 10147792
    Abstract: A semiconductor device, including a substrate, a deposition layer deposited on the substrate, a semiconductor region selectively provided in the deposition layer, a semiconductor layer provided on the deposition layer and the semiconductor region, a first region and a second region selectively provided in the semiconductor layer, a gate electrode provided on the second region and the semiconductor layer via a gate insulating film, a source electrode in contact with the semiconductor layer and the second region, an interlayer insulating film covering the gate electrode, a drain electrode provided on the substrate, a plating film selectively provided on the source electrode at portions thereof on which the protective film is not provided, and a pin-shaped electrode connected to the plating film via solder. The second region is not formed directly beneath a portion where the plating film, the protective film and the source electrode are in contact with one another.
    Type: Grant
    Filed: August 31, 2017
    Date of Patent: December 4, 2018
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki Hoshi, Yuichi Harada, Takashi Shiigi
  • Patent number: 10103229
    Abstract: A semiconductor device includes a wide-bandgap semiconductor substrate of a first conductivity type, a wide-bandgap semiconductor deposition layer of the first conductivity type, semiconductor regions of a second conductivity type, a wide-bandgap semiconductor layer of the second conductivity type, first regions of the first conductivity type, and second regions of the first conductivity type. The width w of a plating film formed on a source electrode of the semiconductor device is greater than or equal to 10 ?m. Beneath the plating film, the wide-bandgap semiconductor layer is formed on the surface of one of the semiconductor regions of the second conductivity type.
    Type: Grant
    Filed: October 12, 2016
    Date of Patent: October 16, 2018
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki Hoshi, Yuichi Harada, Takashi Shiigi
  • Publication number: 20180277437
    Abstract: A main semiconductor element and a temperature sensing part are arranged on a single silicon carbide base. The main semiconductor element is a vertical MOSFET and the temperature sensing part is a horizontal diode. An anode region of the temperature sensing part and an n+-type source region and a p+-type contact region of the main semiconductor element are connected by wiring by an anode electrode on a front surface of the silicon carbide base. The temperature sensing part, when the main semiconductor element is ON, is forward biased by drift current flowing in the main semiconductor element. The temperature sensing part, for example, is a poly-silicon diode constituted by a p-type poly-silicon layer and an n-type poly-silicon layer arranged on the front surface of the silicon carbide base. With such configuration, a semiconductor device having high reliability may be provided.
    Type: Application
    Filed: May 25, 2018
    Publication date: September 27, 2018
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Shoji YAMADA, Takashi SHIIGI, Yasuyuki HOSHI
  • Publication number: 20180277638
    Abstract: A current sensing part that detects overcurrent of a main semiconductor element is arranged on a same silicon carbide base as the main semiconductor element. An isolating part is arranged between the main semiconductor element and the current sensing part. The isolating part has a function of suppressing interference of the main semiconductor element and the current sensing part at the silicon carbide base. The isolating part is constituted by a trench provided a predetermined depth from a front surface of the silicon carbide base. An insulating film is provided in the trench, along inner walls of the trench. A poly-silicon layer is provided on the insulating film. With such a configuration, decreases in breakdown voltage of the current sensing part may be prevented.
    Type: Application
    Filed: May 24, 2018
    Publication date: September 27, 2018
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki HOSHI, Takashi SHIIGI, Shoji YAMADA
  • Patent number: 9997603
    Abstract: In a semiconductor device, an interlayer insulating film electrically insulating a gate electrode and a source electrode has a structure in which a BPSG film and a NSG film are sequentially stacked. Further, the interlayer insulating film has a structure in which the BPSG film, the NSG film, and a SiN film are sequentially stacked, or a structure in which the BPSG film, the SiN film, and the NSG film are sequentially stacked. Such a structure enables the reliability of the semiconductor device in which a pin-shaped electrode is bonded by solder to be improved.
    Type: Grant
    Filed: August 25, 2017
    Date of Patent: June 12, 2018
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki Hoshi, Yuichi Harada, Takashi Shiigi
  • Publication number: 20180006122
    Abstract: A semiconductor device, including a substrate, a deposition layer deposited on the substrate, a semiconductor region selectively provided in the deposition layer, a semiconductor layer provided on the deposition layer and the semiconductor region, a first region and a second region selectively provided in the semiconductor layer, a gate electrode provided on the second region and the semiconductor layer via a gate insulating film, a source electrode in contact with the semiconductor layer and the second region, an interlayer insulating film covering the gate electrode, a drain electrode provided on the substrate, a plating film selectively provided on the source electrode at portions thereof on which the protective film is not provided, and a pin-shaped electrode connected to the plating film via solder. The second region is not formed directly beneath a portion where the plating film, the protective film and the source electrode are in contact with one another.
    Type: Application
    Filed: August 31, 2017
    Publication date: January 4, 2018
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki HOSHI, Yuichi HARADA, Takashi SHIIGI
  • Publication number: 20170365665
    Abstract: On a front surface of an n+-type SiC substrate becoming a drain region, an n?-type drift layer, a p-type base layer, and an n+-type source layer are sequentially formed by epitaxial growth. In the n+-type source layer, the p+-type contact region is selectively provided. A trench is provided penetrating the n+-type source layer and the p-type base layer in the depth direction and reaching the n?-type drift layer. In the trench, a gate electrode is provided via a gate insulating film. A width between adjacent trenches is, for example, 1 ?m or less. A depth of the trench is, for example, 1 ?m or less. The width is narrow whereby substantially the entire p-type base layer forms a channel. A cell includes a FinFET structure in which one channel is sandwiched between MOS gates on both side. Thus, ON resistance may be reduced and decreased reliability may be prevented.
    Type: Application
    Filed: August 30, 2017
    Publication date: December 21, 2017
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki HOSHI, Masahito OTSUKI, Shoji YAMADA, Takashi SHIIGI
  • Publication number: 20170352733
    Abstract: In a semiconductor device, an interlayer insulating film electrically insulating a gate electrode and a source electrode has a structure in which a BPSG film and a NSG film are sequentially stacked. Further, the interlayer insulating film has a structure in which the BPSG film, the NSG film, and a SiN film are sequentially stacked, or a structure in which the BPSG film, the SiN film, and the NSG film are sequentially stacked. Such a structure enables the reliability of the semiconductor device in which a pin-shaped electrode is bonded by solder to be improved.
    Type: Application
    Filed: August 25, 2017
    Publication date: December 7, 2017
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yasuyuki HOSHI, Yuichi HARADA, Takashi SHIIGI
  • Publication number: 20170110544
    Abstract: A semiconductor device includes a wide-bandgap semiconductor substrate of a first conductivity type, a wide-bandgap semiconductor deposition layer of the first conductivity type, semiconductor regions of a second conductivity type, a wide-bandgap semiconductor layer of the second conductivity type, first regions of the first conductivity type, and second regions of the first conductivity type. The width w of a plating film formed on a source electrode of the semiconductor device is greater than or equal to 10 ?m. Beneath the plating film, the wide-bandgap semiconductor layer is formed on the surface of one of the semiconductor regions of the second conductivity type.
    Type: Application
    Filed: October 12, 2016
    Publication date: April 20, 2017
    Applicant: Fuji Electric Co., Ltd.
    Inventors: Yasuyuki HOSHI, Yuichi HARADA, Takashi SHIIGI