Patents by Inventor Tatsuo Harada

Tatsuo 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).

  • Patent number: 11824014
    Abstract: According to one aspect, a semiconductor device includes: a buffer layer disposed on a front surface of a second semiconductor layer, and having at least one opening in plan view; and an electrode disposed over the second semiconductor layer and the buffer layer, and being in contact with the second semiconductor layer through the at least one opening, wherein the buffer layer has a higher Vickers hardness than the electrode, and a width w of each of the at least one opening satisfies w<Wth, where s is a thickness of the buffer layer, t is a thickness of the electrode, and Wth=2×(s×t?s2)0.5 holds true.
    Type: Grant
    Filed: January 21, 2021
    Date of Patent: November 21, 2023
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akito Nishii, Tatsuo Harada, Katsumi Uryu, Noritsugu Nomura, Sho Tanaka
  • Patent number: 11810970
    Abstract: A semiconductor device includes a substrate, a drift layer provided on an upper surface side of the substrate, a base layer provided on the upper surface side of the drift layer, an upper semiconductor layer provided on the upper surface side of the base layer, a first electrode provided on the upper surface of the substrate, a second electrode provided on a rear surface of the substrate, a trench extending to the drift layer from the upper surface of the substrate and a gate electrode provided inside the trench, wherein an inner side surface of the trench has a first surface and a second surface provided below the first surface, the second surface tilts inward of the trench with respect to the first surface, and an intersection point of the first surface and the second surface is provided below the base layer.
    Type: Grant
    Filed: August 10, 2021
    Date of Patent: November 7, 2023
    Assignee: Mitsubishi Electric Corporation
    Inventor: Tatsuo Harada
  • Publication number: 20230170404
    Abstract: Peak concentration of the carrier accumulation layer is equal to or higher than 1.0E16/cm3. A bottom part of the trench is positioned inside the n-type carrier accumulation layer. When a concentration ratio is a result of division of a concentration of the carrier accumulation layer by a concentration of the drift layer at a depth of the bottom part of the trench, the depth of the bottom part of the trench is a position at which the concentration ratio is larger than one and equal to or smaller than 10.
    Type: Application
    Filed: July 6, 2022
    Publication date: June 1, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventor: Tatsuo HARADA
  • Publication number: 20220254908
    Abstract: A semiconductor device includes a substrate, a drift layer provided on an upper surface side of the substrate, a base layer provided on the upper surface side of the drift layer, an upper semiconductor layer provided on the upper surface side of the base layer, a first electrode provided on the upper surface of the substrate, a second electrode provided on a rear surface of the substrate, a trench extending to the drift layer from the upper surface of the substrate and a gate electrode provided inside the trench, wherein an inner side surface of the trench has a first surface and a second surface provided below the first surface, the second surface tilts inward of the trench with respect to the first surface, and an intersection point of the first surface and the second surface is provided below the base layer.
    Type: Application
    Filed: August 10, 2021
    Publication date: August 11, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventor: Tatsuo HARADA
  • Publication number: 20220140748
    Abstract: An inverter device includes first and second input terminals, a series circuit having a plurality of switch elements coupled between the first and second input terminals. Each of the switch elements is coupled in parallel with a series circuit having a diode and an inductor.
    Type: Application
    Filed: November 5, 2020
    Publication date: May 5, 2022
    Inventors: Tetsu TODA, Tatsuo HARADA, Daisuke IIJIMA, Syuuichi KIKUCHI, Kotaro KURODA
  • Publication number: 20210305174
    Abstract: According to one aspect, a semiconductor device includes: a buffer layer disposed on a front surface of a second semiconductor layer, and having at least one opening in plan view; and an electrode disposed over the second semiconductor layer and the buffer layer, and being in contact with the second semiconductor layer through the at least one opening, wherein the buffer layer has a higher Vickers hardness than the electrode, and a width w of each of the at least one opening satisfies w<Wth, where s is a thickness of the buffer layer, t is a thickness of the electrode, and Wth=2×(s×t?s2)0.5 holds true.
    Type: Application
    Filed: January 21, 2021
    Publication date: September 30, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akito NISHII, Tatsuo HARADA, Katsumi URYU, Noritsugu NOMURA, Sho TANAKA
  • Patent number: 11004964
    Abstract: A semiconductor device includes: a second semiconductor layer in a surface layer of a first semiconductor layer; a third semiconductor layer in a surface layer of the second semiconductor layer; a first trench penetrating the second semiconductor layer and the third semiconductor layer to reach an inside of the first semiconductor layer; a second trench penetrating, from an upper surface of the first semiconductor layer, the third semiconductor layer to reach an inside of the second semiconductor layer; and a fourth semiconductor layer in contact with a bottom of the second trench.
    Type: Grant
    Filed: October 3, 2019
    Date of Patent: May 11, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventor: Tatsuo Harada
  • Publication number: 20200194574
    Abstract: A semiconductor device includes: a second semiconductor layer in a surface layer of a first semiconductor layer; a third semiconductor layer in a surface layer of the second semiconductor layer; a first trench penetrating the second semiconductor layer and the third semiconductor layer to reach an inside of the first semiconductor layer; a second trench penetrating, from an upper surface of the first semiconductor layer, the third semiconductor layer to reach an inside of the second semiconductor layer, and a fourth semiconductor layer in contact with a bottom of the second trench.
    Type: Application
    Filed: October 3, 2019
    Publication date: June 18, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventor: Tatsuo HARADA
  • Patent number: 10411093
    Abstract: An active cell region, an edge termination region surrounding the active cell region and an intermediate region located at an intermediate position between these regions are provided, the active cell region has a trench gate type MOS structure on a top side, and a vertical structure on a bottom side includes a p-collector layer, an n-buffer layer on the p-collector layer, and an n-drift layer on the n-buffer layer, the n-buffer layer has a first buffer portion provided on the p-collector layer side, and a second buffer portion provided on the n-drift layer side, the peak impurity concentration of the first buffer portion is higher than the peak impurity concentration of the second buffer portion, and the impurity concentration gradient on the n-drift layer side of the second buffer portion is gentler than the impurity concentration gradient on the n-drift layer side of the first buffer portion.
    Type: Grant
    Filed: December 28, 2015
    Date of Patent: September 10, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Katsumi Nakamura, Tatsuo Harada, Noritsugu Nomura
  • Publication number: 20190109026
    Abstract: Provided is a technique for detaching a semiconductor chip from a mount tape without failures in the semiconductor chip, such as cracking and chipping. A semiconductor pick-up apparatus includes the following components: a pick-up stage above which a semiconductor chip is to be placed through a mount tape attached to the lower surface of the semiconductor chip; an expander holding and expanding the mount tape; a push-up needle projecting from the upper surface of the pick-up stage, and capable of pushing up the semiconductor chip through the mount tape; and a mechanism pushing up the push-up needle while operating the push-up needle so as to form a spiral shape.
    Type: Application
    Filed: August 6, 2018
    Publication date: April 11, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kinya YAMASHITA, Masaki UENO, Tatsuo HARADA, Noritsugu NOMURA
  • Publication number: 20180248003
    Abstract: An active cell region, an edge termination region surrounding the active cell region and an intermediate region located at an intermediate position between these regions are provided, the active cell region has a trench gate type MOS structure on a top side, and a vertical structure on a bottom side includes a p-collector layer, an n-buffer layer on the p-collector layer, and an n-drift layer on the n-buffer layer, the n-buffer layer has a first buffer portion provided on the p-collector layer side, and a second buffer portion provided on the n-drift layer side, the peak impurity concentration of the first buffer portion is higher than the peak impurity concentration of the second buffer portion, and the impurity concentration gradient on the n-drift layer side of the second buffer portion is gentler than the impurity concentration gradient on the n-drift layer side of the first buffer portion.
    Type: Application
    Filed: December 28, 2015
    Publication date: August 30, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Katsumi NAKAMURA, Tatsuo HARADA, Noritsugu NOMURA
  • Publication number: 20170154955
    Abstract: A semiconductor device includes: a semiconductor substrate; a device region on the semiconductor substrate; a planar edge termination region on the semiconductor substrate to surround the device region; and a passivation film covering the edge termination region, wherein the passivation film includes a semi-insulating film directly contacting the semiconductor substrate.
    Type: Application
    Filed: June 6, 2016
    Publication date: June 1, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuo HARADA, Shigeto HONDA, Akito NISHII, Ze CHEN
  • Publication number: 20140199823
    Abstract: An SOT substrate (6), in which a silicon layer (5) is provided on a silicon substrate (3) via a silicon oxide film (4), is formed. Next, a plurality of semiconductor elements (8) is formed on a surface of the silicon layer (5). Next, wiring (11) is formed on a surface of an insulating substrate (10). Next, the SOI substrate (6) and the insulating substrate (10) are pasted together so that the plurality of semiconductor elements (8) and the wiring (11) are electrically connected together. Next, at least one of hydrogen ions and rare gas ions are injected into the silicon substrate (3) to form a brittle layer (12). Next, part of the silicon substrate (3) is peeled away from the brittle layer (12) as a boundary.
    Type: Application
    Filed: June 10, 2011
    Publication date: July 17, 2014
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Noritsugu Nomura, Akira Okada, Tatsuo Harada
  • Patent number: 8112980
    Abstract: A finish for synthetic filament yarn which decreases broken filaments and ends down in friction false-twist texturing includes 40 to 98 wt % of a polyether compound, and essentially comprises components (A) and (B); wherein the component (A) is at least one member selected from the group consisting of (A1) a C1-C10 fatty acid, (A2) a C1-C10 hydroxyfatty acid, (A3) a sarcosine derivative, and salts thereof, and the amount of the component (A) in the finish ranges from 0.05 to 5 wt %; and wherein the component (B) is an alkylphosphate salt and the amount of the component (B) in the finish ranges from 0.01 to 3 wt %.
    Type: Grant
    Filed: September 2, 2008
    Date of Patent: February 14, 2012
    Assignee: Matsumoto Yushi-Seiyaku Co., Ltd.
    Inventors: Shinichi Tatemoto, Tatsuo Harada, Kaori Kimoto
  • Publication number: 20100199624
    Abstract: The present invention aims to provide a finish for synthetic filament yarn processed in friction false-twist texturing, which decreases broken filaments and ends down in false-twist texturing with a synthetic filament yarn applied with the finish, finish-application emulsion of the finish, synthetic filament yarn applied with the emulsion, manufacturing process of the synthetic filament yarn, and resultant yarns. The finish for synthetic filament yarn processed in friction false-twist texturing of the present invention comprises 40 to 98 wt % of a polyether compound, and essentially comprises components (A) and (B); wherein the component (A) is at least one member selected from the group consisting of (A1) a C1-C10 fatty acid, (A2) a C1-C10 hydroxyfatty acid, (A3) a sarcosine derivative, and salts thereof, and the amount of the component (A) in the finish ranges from 0.05 to 5 wt %; and wherein the component (B) is an alkylphosphate salt and the amount of the component (B) in the finish ranges from 0.
    Type: Application
    Filed: September 2, 2008
    Publication date: August 12, 2010
    Applicant: MATSUMOTO YUSHI-SEIYAKU CO., LTD.
    Inventors: Shinichi Tatemoto, Tatsuo Harada, Kaori Kimoto
  • Patent number: 7750438
    Abstract: An n-type buffer region 6 is arranged between an n? drift region 1 and a p-type collector region 7, and has a higher impurity concentration than n? drift region 1 Assuming that ? represents the ratio (WTA/WTB) between WTA expressed as: WTA = 2 ? ? s ? ? 0 ? V qNd and the thickness WTB of the drift region held between the base region and the buffer region, the ratio (DC/DB) of the net dose DC of the collector region with respect to the net dose DB of the buffer region is at least ?. Thus, a semiconductor device capable of ensuring a proper margin of SCSOA resistance can be obtained.
    Type: Grant
    Filed: January 21, 2009
    Date of Patent: July 6, 2010
    Assignee: Mitsubishi Electric Corporation
    Inventor: Tatsuo Harada
  • Publication number: 20100052011
    Abstract: An n-type buffer region 6 is arranged between an n? drift region 1 and a p-type collector region 7, and has a higher impurity concentration than n? drift region 1 Assuming that ? represents the ratio (WTA/WTB) between WTA expressed as: WTA = 2 ? ? s ? ? 0 ? V qNd and the thickness WTB of the drift region held between the base region and the buffer region, the ratio (DC/DB) of the net dose DC of the collector region with respect to the net dose DB of the buffer region is at least ?. Thus, a semiconductor device capable of ensuring a proper margin of SCSOA resistance can be obtained.
    Type: Application
    Filed: January 21, 2009
    Publication date: March 4, 2010
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventor: Tatsuo HARADA
  • Patent number: 7615846
    Abstract: An emitter layer is provided in stripes in a direction orthogonal to an effective gate trench region connected to a gate electrode and a dummy trench region isolated from the gate electrode. A width of the emitter layer is determined to satisfy a predetermined relational expression so as not to cause latch-up in an underlying P base layer. In the predetermined relational expression, an upper limit value of the width W of the emitter layer is (3500/Rspb)·Wso·exp(decimation ratio), where Rspb is a sheet resistance of the P base layer immediately below the emitter layer, Wso is an interval between the trenches, and the decimation ratio is a ratio of the number of the effective gate trench region to the total number of the trench regions. Variations in saturation current in a trench IGBT can be suppressed, and a tolerance of an Reverse Bias Safe Operation Area can be improved.
    Type: Grant
    Filed: December 31, 2007
    Date of Patent: November 10, 2009
    Assignee: Mitsubishi Electric Corporation
    Inventor: Tatsuo Harada
  • Publication number: 20090020852
    Abstract: An emitter layer is provided in stripes in a direction orthogonal to an effective gate trench region connected to a gate electrode and a dummy trench region isolated from the gate electrode. A width of the emitter layer is determined to satisfy a predetermined relational expression so as not to cause latch-up in an underlying P base layer. In the predetermined relational expression, an upper limit value of the width W of the emitter layer is (3500/Rspb)·Wso·exp(decimation ratio), where Rspb is a sheet resistance of the P base layer immediately below the emitter layer, Wso is an interval between the trenches, and the decimation ratio is a ratio of the number of the effective gate trench region to the total number of the trench regions. Variations in saturation current in a trench IGBT can be suppressed, and a tolerance of an Reverse Bias Safe Operation Area can be improved.
    Type: Application
    Filed: December 31, 2007
    Publication date: January 22, 2009
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventor: Tatsuo HARADA
  • Patent number: 7358565
    Abstract: An n-type first base layer is formed on a semiconductor substrate 1 having a first major surface and a second major surface, and a p-type second base layer is formed thereon. Between the first base layer and the second base layer, a carrier stored layer is formed. The carrier stored layer has a high-concentration impurity layer and a low concentration impurity layer, and the high-concentration impurity layer has a thickness of 1.5 ?m or more and an impurity concentration therethrough is made to be 1.0×1016 cm?3 or more throughout the layer.
    Type: Grant
    Filed: September 5, 2006
    Date of Patent: April 15, 2008
    Assignee: Mitsubishi Electric Corporation
    Inventor: Tatsuo Harada