Patents by Inventor Mitsuhiro KAKEFU

Mitsuhiro KAKEFU 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: 20230282622
    Abstract: A semiconductor device including a semiconductor unit that has a first arm part, which includes: first and second semiconductor chips having first and second control electrodes on their front surfaces, a first circuit pattern where the first and second semiconductor chips are disposed, a second circuit pattern to which the first and second control electrodes are connected, and a first control wire electrically connecting the first and second control electrodes and the second circuit pattern sequentially in a direction; and a second arm part, which includes third and fourth semiconductor chips having third and fourth control electrodes on their front surfaces, a third circuit pattern where the third and fourth semiconductor chips are disposed, a fourth circuit pattern to which the third and fourth control electrodes are connected, and a second control wire electrically connecting the third and fourth control electrodes and the fourth circuit pattern sequentially in the direction.
    Type: Application
    Filed: May 12, 2023
    Publication date: September 7, 2023
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Mitsuhiro KAKEFU, Hiroaki ICHIKAWA
  • Patent number: 11688722
    Abstract: A semiconductor device, having a first semiconductor chip including a first side portion at a front surface thereof and a first control electrode formed in the first side portion, a second semiconductor chip including a second side portion at a front surface thereof and a second control electrode formed in the second side portion, a first circuit pattern, on which the first semiconductor chip and the second semiconductor chip are disposed, a second circuit pattern, and a first control wire electrically connecting the first control electrode, the second control electrode, and the second circuit pattern. The first side portion and the second side portion are aligned. The first control electrode and the second control electrode are aligned. The second circuit pattern are aligned with the first control electrode and the second control electrode.
    Type: Grant
    Filed: January 21, 2021
    Date of Patent: June 27, 2023
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Mitsuhiro Kakefu, Hiroaki Ichikawa
  • Patent number: 11515292
    Abstract: A semiconductor device, having a first semiconductor chip including a first side portion at a front surface thereof and a first control electrode formed in the first side portion, a second semiconductor chip including a second side portion at a front surface thereof and a second control electrode formed in the second side portion, a first circuit pattern, on which the first semiconductor chip and the second semiconductor chip are disposed, a second circuit pattern, and a first control wire electrically connecting the first control electrode, the second control electrode, and the second circuit pattern. The first side portion and the second side portion are aligned. The first control electrode and the second control electrode are aligned. The second circuit pattern are aligned with the first control electrode and the second control electrode.
    Type: Grant
    Filed: August 27, 2020
    Date of Patent: November 29, 2022
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Mitsuhiro Kakefu, Hiroaki Ichikawa
  • Publication number: 20210143132
    Abstract: A semiconductor device, having a first semiconductor chip including a first side portion at a front surface thereof and a first control electrode formed in the first side portion, a second semiconductor chip including a second side portion at a front surface thereof and a second control electrode formed in the second side portion, a first circuit pattern, on which the first semiconductor chip and the second semiconductor chip are disposed, a second circuit pattern, and a first control wire electrically connecting the first control electrode, the second control electrode, and the second circuit pattern. The first side portion and the second side portion are aligned. The first control electrode and the second control electrode are aligned. The second circuit pattern are aligned with the first control electrode and the second control electrode.
    Type: Application
    Filed: January 21, 2021
    Publication date: May 13, 2021
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Mitsuhiro KAKEFU, Hiroaki ICHIKAWA
  • Publication number: 20200395343
    Abstract: A semiconductor device, having a first semiconductor chip including a first side portion at a front surface thereof and a first control electrode formed in the first side portion, a second semiconductor chip including a second side portion at a front surface thereof and a second control electrode formed in the second side portion, a first circuit pattern, on which the first semiconductor chip and the second semiconductor chip are disposed, a second circuit pattern, and a first control wire electrically connecting the first control electrode, the second control electrode, and the second circuit pattern. The first side portion and the second side portion are aligned. The first control electrode and the second control electrode are aligned. The second circuit pattern are aligned with the first control electrode and the second control electrode.
    Type: Application
    Filed: August 27, 2020
    Publication date: December 17, 2020
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Mitsuhiro KAKEFU, Hiroaki ICHIKAWA
  • Patent number: 10535729
    Abstract: In a semiconductor device including a low lifetime region of a depth within a range on both sides sandwiching a p-n junction of a p-type semiconductor region bottom portion, the low lifetime region includes a central region that has a portion coinciding with the semiconductor region as seen from one main surface side and is selectively formed as far as the position of a contact end portion of a region of the coinciding portion with which the semiconductor region and a metal electrode are in contact, a peripheral region wherein the central region extends as far as the position of an outer peripheral end of the semiconductor region, and an expanded end portion region wherein the peripheral region extends as far as an outer peripheral end of the innermost of guard rings. Because of this, it is possible to reduce leakage current while maintaining high reverse recovery current resistance.
    Type: Grant
    Filed: April 24, 2018
    Date of Patent: January 14, 2020
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventor: Mitsuhiro Kakefu
  • Publication number: 20180240866
    Abstract: In a semiconductor device including a low lifetime region of a depth within a range on both sides sandwiching a p-n junction of a p-type semiconductor region bottom portion, the low lifetime region includes a central region that has a portion coinciding with the semiconductor region as seen from one main surface side and is selectively formed as far as the position of a contact end portion of a region of the coinciding portion with which the semiconductor region and a metal electrode are in contact, a peripheral region wherein the central region extends as far as the position of an outer peripheral end of the semiconductor region, and an expanded end portion region wherein the peripheral region extends as far as an outer peripheral end of the innermost of guard rings. Because of this, it is possible to reduce leakage current while maintaining high reverse recovery current resistance.
    Type: Application
    Filed: April 24, 2018
    Publication date: August 23, 2018
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventor: Mitsuhiro Kakefu
  • Patent number: 10056501
    Abstract: Provided is a device with improved reverse-recovery immunity of a diode element. The device includes: a first conductivity-type drift layer; a second conductivity-type anode region provided in an upper portion of the drift layer; a second conductivity-type extraction region in contact with and surrounding the anode region; and a second conductivity-type field limiting ring region surrounding and separated from the extraction region at the upper portion of the drift layer, wherein the extraction region has a greater depth than the anode region and the field limiting ring region.
    Type: Grant
    Filed: December 27, 2016
    Date of Patent: August 21, 2018
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventor: Mitsuhiro Kakefu
  • Patent number: 9985090
    Abstract: In a semiconductor device including a low lifetime region of a depth within a range on both sides sandwiching a p-n junction of a p-type semiconductor region bottom portion, the low lifetime region includes a central region that has a portion coinciding with the semiconductor region as seen from one main surface side and is selectively formed as far as the position of a contact end portion of a region of the coinciding portion with which the semiconductor region and a metal electrode are in contact, a peripheral region wherein the central region extends as far as the position of an outer peripheral end of the semiconductor region, and an expanded end portion region wherein the peripheral region extends as far as an outer peripheral end of the innermost of guard rings. Because of this, it is possible to reduce leakage current while maintaining high reverse recovery current resistance.
    Type: Grant
    Filed: December 11, 2013
    Date of Patent: May 29, 2018
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventor: Mitsuhiro Kakefu
  • Publication number: 20170110596
    Abstract: Provided is a device with improved reverse-recovery immunity of a diode element. The device includes: a first conductivity-type drift layer; a second conductivity-type anode region provided in an upper portion of the drift layer; a second conductivity-type extraction region in contact with and surrounding the anode region; and a second conductivity-type field limiting ring region surrounding and separated from the extraction region at the upper portion of the drift layer, wherein the extraction region has a greater depth than the anode region and the field limiting ring region.
    Type: Application
    Filed: December 27, 2016
    Publication date: April 20, 2017
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventor: Mitsuhiro KAKEFU
  • Patent number: 9040362
    Abstract: A method of manufacturing a MOS type semiconductor device, includes, before forming a semiconductor functional structure including a necessary MOS gate structure on one principal surface of a silicon semiconductor substrate, in the order recited, a first step of heating the silicon semiconductor substrate in an oxygen-containing atmosphere under heat treatment conditions including a heat treatment temperature of higher than 1,280° C. and a heat treatment time necessary for introducing oxygen up to a solid solution limit concentration in the silicon semiconductor substrate as a whole body; and a second step of holding the silicon semiconductor substrate at a specified temperature in a range from 1,000° C. to 1,200° C. The method achieves small turn-off loss and little variation of ON voltages without controlling a collector layer to a lower concentration than the conventional technology.
    Type: Grant
    Filed: October 10, 2014
    Date of Patent: May 26, 2015
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventor: Mitsuhiro Kakefu
  • Publication number: 20150126000
    Abstract: A method of manufacturing a MOS type semiconductor device, includes, before forming a semiconductor functional structure including a necessary MOS gate structure on one principal surface of a silicon semiconductor substrate, in the order recited, a first step of heating the silicon semiconductor substrate in an oxygen-containing atmosphere under heat treatment conditions including a heat treatment temperature of higher than 1,280° C. and a heat treatment time necessary for introducing oxygen up to a solid solution limit concentration in the silicon semiconductor substrate as a whole body; and a second step of holding the silicon semiconductor substrate at a specified temperature in a range from 1,000° C. to 1,200° C. The method achieves small turn-off loss and little variation of ON voltages without controlling a collector layer to a lower concentration than the conventional technology.
    Type: Application
    Filed: October 10, 2014
    Publication date: May 7, 2015
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventor: Mitsuhiro KAKEFU
  • Publication number: 20150108539
    Abstract: A fabrication method of a semiconductor device includes forming a mask insulating film having a specified thickness on the top surface of an n-type semiconductor substrate, forming an opening at a specified position in the mask insulating film, carrying out ion implantation with p-type impurity ions onto the top surface, removing a layer portion formed in the mask insulating film with the p-type impurities included by the ion implantation, and carrying out heat treatment to diffuse the p-type impurities implanted into the n-type semiconductor substrate from the opening to a depth, thereby forming the p-type isolation region.
    Type: Application
    Filed: September 12, 2014
    Publication date: April 23, 2015
    Inventor: Mitsuhiro KAKEFU
  • Publication number: 20140159192
    Abstract: In a semiconductor device including a low lifetime region of a depth within a range on both sides sandwiching a p-n junction of a p-type semiconductor region bottom portion, the low lifetime region includes a central region that has a portion coinciding with the semiconductor region as seen from one main surface side and is selectively formed as far as the position of a contact end portion of a region of the coinciding portion with which the semiconductor region and a metal electrode are in contact, a peripheral region wherein the central region extends as far as the position of an outer peripheral end of the semiconductor region, and an expanded end portion region wherein the peripheral region extends as far as an outer peripheral end of the innermost of guard rings. Because of this, it is possible to reduce leakage current while maintaining high reverse recovery current resistance.
    Type: Application
    Filed: December 11, 2013
    Publication date: June 12, 2014
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventor: Mitsuhiro KAKEFU
  • Publication number: 20140117406
    Abstract: A reverse blocking IGBT is disclosed in which a lifetime control region formed by helium ion irradiation is selectively provided in a region within a range approximately corresponding to the planar pattern of a p-type base region in the direction along the principal surface of a silicon semiconductor substrate of n-type and within a range from the upward vicinity to the downward vicinity of the p-n junction on the bottom of the p-type base region in the direction of the depth of the silicon semiconductor substrate. This can provide a reverse blocking MOS semiconductor device capable of further decreasing a reverse leakage current less than the current in a previous device while making the influence on an on-state current small.
    Type: Application
    Filed: October 16, 2013
    Publication date: May 1, 2014
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventor: Mitsuhiro KAKEFU
  • Patent number: D884662
    Type: Grant
    Filed: November 7, 2018
    Date of Patent: May 19, 2020
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Taichi Itoh, Hiroaki Ichikawa, Mitsuhiro Kakefu, Akio Yamano, Takuya Yamamoto