Patents by Inventor Takahiro Tamura

Takahiro Tamura 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: 10304928
    Abstract: Provided is a semiconductor device including a semiconductor substrate doped with impurities, a front surface-side electrode provided on a front surface side of the semiconductor substrate, a back surface-side electrode provided on a back surface side of the semiconductor substrate, wherein the semiconductor substrate has a peak region arranged on the back surface side of the semiconductor substrate and having one or more peaks of impurity concentration, a high concentration region arranged closer to the front surface than the peak region and having a gentler impurity concentration than the one or more peaks, and a low concentration region arranged closer to the front surface than the high concentration region and having a lower impurity concentration than the high concentration region.
    Type: Grant
    Filed: May 30, 2017
    Date of Patent: May 28, 2019
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Takahiro Tamura, Yuichi Onozawa, Takashi Yoshimura, Hiroshi Takishita, Akio Yamano
  • Publication number: 20190113588
    Abstract: A magnetic resonance imaging apparatus according to the present embodiment includes sequence control circuitry. The sequence control circuitry collect first MR data in a first cardiac cycle by excitation of a first region including a first slice, and collects reference data used for phase correction of second MR data on a second slice not included in the first region before and after the collection of the first MR data in the first cardiac cycle.
    Type: Application
    Filed: October 1, 2018
    Publication date: April 18, 2019
    Applicant: Canon Medical Systems Corporation
    Inventors: Takahiro TAMURA, Hiroshi TAKAI, Nobuyuki KONUMA
  • Publication number: 20190001338
    Abstract: The media-circulation type pulverizer comprising: an agitating member disposed in a lower region of a pulverization chamber and having a rotary shaft substantially coaxial with a central axis of the pulverization chamber; an annular partition wall disposed to extend upwardly from a position surrounding an outer periphery of the agitating member or a position radially away from the outer periphery by a given distance, so as to radially divide an internal space of the pulverization chamber to form an inner region of a pulverization chamber and an annular outer region of a pulverization chamber; a media guide member provided on a central area of a lower surface of the end plate to extend downwardly and configured to turn a mixture of a raw material slurry and pulverizing media being moved upwardly through the outer region of the pulverization chamber by an action of the agitating member, to a downward flow so as to direct the mixture toward the inner region of the pulverization chamber; a media separation member
    Type: Application
    Filed: April 11, 2017
    Publication date: January 3, 2019
    Inventors: Tsuyoshi ISHIKAWA, Yasuhiro MITSUHASHI, Takahiro TAMURA, Tsubasa NAKAJIMA
  • Patent number: 10158011
    Abstract: A trench gate type MOS gate structure is provided in an active region on a substrate front surface side, and a floating p-type region is provided in a mesa region between trenches. A groove is provided distanced from the trench in a surface layer on the substrate front surface side of the floating p-type region. A second gate electrode is provided across an insulation layer in the interior portion of the groove. The second gate electrode covers the surface on the substrate front surface side of the floating p-type region. Thus, the second gate electrode is embedded in a surface layer on the substrate front surface side of the floating p-type region between the floating p-type region and an interlayer dielectric, whereby the substrate front surface is flattened. Controllability of turn-on di/dt is high, mirror capacitance is low, and an element structure having an intricate pattern can be formed.
    Type: Grant
    Filed: March 15, 2016
    Date of Patent: December 18, 2018
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Yuichi Onozawa, Takahiro Tamura
  • Publication number: 20180284212
    Abstract: According to one embodiment, an MRI apparatus includes sequence control circuitry that performs first scanning and second scanning along mutually opposite radial directions in k-space, crossing over a k-space origin, and performs third scanning, and processing circuitry that generates first and second projection images by respectively applying a one-dimensional Fourier transform for the directions to first and second MR signals respectively acquired by the first and second scanning, determines correction coefficients related to transient response characteristics of a readout gradient magnetic field by a calculating process to reduce a difference between the first and second projection images, and generates a corrected image in which the transient response characteristics are corrected using the correction coefficients and MR signals acquired by the third scanning.
    Type: Application
    Filed: March 29, 2018
    Publication date: October 4, 2018
    Applicant: Canon Medical Systems Corporation
    Inventors: Daiki TAMADA, Takahiro TAMURA
  • Publication number: 20180233554
    Abstract: A semiconductor device is provided, including: a semiconductor substrate having an active area and an edge termination region; an upper electrode; an insulating film provided between the semiconductor substrate and the upper electrode and having a contact hole; a first conductivity-type drift region; a second conductivity-type base region; a second conductivity-type well region; and a second conductivity-type extension region formed extending in a direction toward the well region from the base region and separated from the upper electrode by the insulating film, wherein a sum of a first distance from an end portion of the contact hole closer to the well region to an end portion of the extension region closer to the well region and a second distance from the end portion of the extension region closer to the well region to the well region is smaller than a thickness of the semiconductor substrate in the active area.
    Type: Application
    Filed: February 15, 2018
    Publication date: August 16, 2018
    Inventors: Kaname Mitsuzuka, Yuichi Onozawa, Takahiro Tamura
  • Publication number: 20180166279
    Abstract: A semiconductor device is provided. The semiconductor device includes: a first region formed on a front surface side of a semiconductor substrate; a drift region formed closer to a rear surface of the semiconductor substrate than the first region is; a buffer region that: is formed closer to the rear surface of the semiconductor substrate than the drift region is; and has one or more peaks of an impurity concentration that are higher than an impurity concentration of the drift region; and a lifetime killer that: is arranged on a rear surface side of the semiconductor substrate; and shortens a carrier lifetime, wherein a peak of a concentration of the lifetime killer is arranged between: a peak that is closest to a front surface of the semiconductor substrate among the peaks of the impurity concentration in the buffer region; and the rear surface of the semiconductor substrate.
    Type: Application
    Filed: January 24, 2018
    Publication date: June 14, 2018
    Inventors: Takahiro TAMURA, Yuichi ONOZAWA, Misaki TAKAHASHI
  • Patent number: 9954078
    Abstract: A method of manufacturing a super junction MOSFET, which includes a parallel pn layer including a plurality of pn junctions and in which an n-type drift region and a p-type partition region interposed between the pn junctions are alternately arranged and contact each other, a MOS gate structure on the surface of the parallel pn layer, and an n-type buffer layer in contact with an opposite main surface. The impurity concentration of the buffer layer is equal to or less than that of the n-type drift region. At least one of the p-type partition regions in the parallel pn layer is replaced with an n? region with a lower impurity concentration than the n-type drift region.
    Type: Grant
    Filed: June 19, 2017
    Date of Patent: April 24, 2018
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Takahiro Tamura, Yasuhiko Onishi
  • Publication number: 20180061935
    Abstract: To prevent an intermediate region from contacting a cathode electrode even if a cathode region is partially defective. There is provided a semiconductor device with a semiconductor substrate that has a field stop region where first impurities of a first conduction type are implanted, an intermediate region that is formed on a back surface side of the field stop region and where second impurities of a second conduction type are implanted, and a cathode region of the first conduction type that is formed on a back surface side of the intermediate region. In a back surface of the semiconductor substrate, a concentration of the first impurities is higher than a concentration of the second impurities.
    Type: Application
    Filed: October 24, 2017
    Publication date: March 1, 2018
    Inventors: Hiroki WAKIMOTO, Yuichi ONOZAWA, Takahiro TAMURA, Eri OGAWA
  • Publication number: 20180005829
    Abstract: Provided is a semiconductor device including: a semiconductor substrate doped with an impurity; a front-surface-side electrode provided at a side of a front surface of the semiconductor substrate; and a back-surface-side electrode provided at a side of a back surface of the semiconductor substrate; wherein the semiconductor substrate includes: a peak region arranged at the side of the back surface of the semiconductor substrate and having one or more peaks of an impurity concentration; a high concentration region arranged closer to the front surface than the peak region and having an impurity concentration more gently sloped than the one or more peaks; and a low concentration region arranged closer to the front surface than the high concentration region and having an impurity concentration lower than the impurity concentration of the high concentration region and a substrate concentration of the semiconductor substrate.
    Type: Application
    Filed: August 29, 2017
    Publication date: January 4, 2018
    Inventors: Hiroshi TAKISHITA, Takashi YOSHIMURA, Takahiro TAMURA, Yuichi ONOZAWA, Akio YAMANO
  • Publication number: 20170294521
    Abstract: A method of manufacturing a super junction MOSFET, which includes a parallel pn layer including a plurality of pn junctions and in which an n-type drift region and a p-type partition region interposed between the pn junctions are alternately arranged and contact each other, a MOS gate structure on the surface of the parallel pn layer, and an n-type buffer layer in contact with an opposite main surface. The impurity concentration of the buffer layer is equal to or less than that of the n-type drift region. At least one of the p-type partition regions in the parallel pn layer is replaced with an n? region with a lower impurity concentration than the n-type drift region.
    Type: Application
    Filed: June 19, 2017
    Publication date: October 12, 2017
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Takahiro TAMURA, Yasuhiko ONISHI
  • Publication number: 20170271447
    Abstract: Provided is a semiconductor device including a semiconductor substrate doped with impurities, a front surface-side electrode provided on a front surface side of the semiconductor substrate, a back surface-side electrode provided on a back surface side of the semiconductor substrate, wherein the semiconductor substrate has a peak region arranged on the back surface side of the semiconductor substrate and having one or more peaks of impurity concentration, a high concentration region arranged closer to the front surface than the peak region and having a gentler impurity concentration than the one or more peaks, and a low concentration region arranged closer to the front surface than the high concentration region and having a lower impurity concentration than the high concentration region.
    Type: Application
    Filed: May 30, 2017
    Publication date: September 21, 2017
    Inventors: Takahiro TAMURA, Yuichi ONOZAWA, Takashi YOSHIMURA, Hiroshi TAKISHITA, Akio YAMANO
  • Patent number: 9711634
    Abstract: A super junction MOSFET includes a parallel pn layer including a plurality of pn junctions and in which an n-type drift region and a p-type partition region interposed between the pn junctions are alternately arranged and contact each other, a MOS gate structure on the surface of the parallel pn layer, and an n-type buffer layer in contact with an opposite main surface. The impurity concentration of the buffer layer is equal to or less than that of the n-type drift region. At least one of the p-type partition regions in the parallel pn layer is replaced with an n? region with a lower impurity concentration than the n-type drift region. With this structure, it is possible to provide a super junction MOSFET which prevents a sharp rise in hard recovery waveform during a reverse recovery operation.
    Type: Grant
    Filed: October 13, 2015
    Date of Patent: July 18, 2017
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Takahiro Tamura, Yasuhiko Onishi
  • Publication number: 20160276446
    Abstract: A semiconductor device comprises: an n-type semiconductor substrate; a p-type anode region formed in the semiconductor substrate on its front surface side; an n-type field stop region formed in the semiconductor substrate on its rear surface side with protons as a donor; and an n-type cathode region formed in the semiconductor substrate to be closer to its rear surface than the field stop region is, wherein a concentration distribution of the donor in the field stop region in its depth direction has a first peak, and a second peak that is closer to the rear surface of the semiconductor substrate than the first peak is, and has a concentration lower than that of the first peak, and a carrier lifetime in at least a partial region between the anode region and the cathode region is longer than carrier lifetimes in the anode region.
    Type: Application
    Filed: June 1, 2016
    Publication date: September 22, 2016
    Inventors: Hiroki WAKIMOTO, Hiroshi TAKISHITA, Takashi YOSHIMURA, Takahiro TAMURA, Yuichi ONOZAWA
  • Publication number: 20160197171
    Abstract: A trench gate type MOS gate structure is provided in an active region on a substrate front surface side, and a floating p-type region is provided in a mesa region between trenches. A groove is provided distanced from the trench in a surface layer on the substrate front surface side of the floating p-type region. A second gate electrode is provided across an insulation layer in the interior portion of the groove. The second gate electrode covers the surface on the substrate front surface side of the floating p-type region. Thus, the second gate electrode is embedded in a surface layer on the substrate front surface side of the floating p-type region between the floating p-type region and an interlayer dielectric, whereby the substrate front surface is flattened. Controllability of turn-on di/dt is high, mirror capacitance is low, and an element structure having an intricate pattern can be formed.
    Type: Application
    Filed: March 15, 2016
    Publication date: July 7, 2016
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yuichi ONOZAWA, Takahiro TAMURA
  • Publication number: 20160035881
    Abstract: A super junction MOSFET includes a parallel pn layer including a plurality of pn junctions and in which an n-type drift region and a p-type partition region interposed between the pn junctions are alternately arranged and contact each other, a MOS gate structure on the surface of the parallel pn layer, and an n-type buffer layer in contact with an opposite main surface. The impurity concentration of the buffer layer is equal to or less than that of the n-type drift region. At least one of the p-type partition regions in the parallel pn layer is replaced with an n? region with a lower impurity concentration than the n-type drift region. With this structure, it is possible to provide a super junction MOSFET which prevents a sharp rise in hard recovery waveform during a reverse recovery operation, and a method for manufacturing the same.
    Type: Application
    Filed: October 13, 2015
    Publication date: February 4, 2016
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Takahiro TAMURA, Yasuhiko ONISHI
  • Patent number: 9219141
    Abstract: A super junction MOSFET is disclosed. The super junction MOSFET includes a plurality of mutually parallel pn junctions extending in a vertical direction on a first principal surface of an n-type semiconductor substrate; a parallel pn layer in which n-type drift regions and p-type partition regions, each sandwiched between the adjacent pn junctions, are disposed alternately in contact with each other; and an MOS gate structure on the first principal surface side of the parallel pn layer, wherein an n-type first buffer layer and second buffer layer are in contact in that order on the opposite principal surface side, and the impurity concentration of the first buffer layer is a concentration that is equal to or less than the same level as that of the impurity concentration of the n-type drift region.
    Type: Grant
    Filed: July 8, 2014
    Date of Patent: December 22, 2015
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Takahiro Tamura, Yasuhiko Onishi
  • Patent number: 9196899
    Abstract: An anode active material for use in a lithium secondary battery including a mixture of graphite I that has, according to X-ray powder diffraction, d002 of not smaller than 0.3354 nm and not greater than 0.337 nm, Lc(004) of smaller than 100 nm, La(110) of not smaller than 100 nm, and a half width of the peak of a plane (101) at a diffraction angle (2?) of 44 degrees to 45 degrees of not smaller than 0.65 degree and another graphite so as to have, according to X-ray powder diffraction, d002 of not smaller than 0.3354 nm and not greater than 0.337 nm, Lc(004) of not smaller than 80 nm, La(110) of not smaller than 100 nm, and a half width of the peak of a plane (101) at a diffraction angle (2?) of 44 degrees to 45 degrees of not smaller than 0.5 degree.
    Type: Grant
    Filed: August 5, 2011
    Date of Patent: November 24, 2015
    Assignee: SHOWA DENKO K.K.
    Inventors: Chiaki Sotowa, Takahiro Tamura
  • Patent number: 9123561
    Abstract: A superjunction semiconductor device is disclosed in which the trade-off relationship between breakdown voltage characteristics and voltage drop characteristics is considerably improved, and it is possible to greatly improve the charge resistance of an element peripheral portion and long-term breakdown voltage reliability. It includes parallel pn layers of n-type drift regions and p-type partition regions in superjunction structure. PN layers are depleted when off-state voltage is applied. Repeating pitch of the second parallel pn layer in a ring-like element peripheral portion encircling the element active portion is smaller than repeating pitch of the first parallel pn layer in the element active portion. Element peripheral portion includes low concentration n-type region on the surface of the second parallel pn layer. The depth of p-type partition region of an outer peripheral portion in the element peripheral portion is smaller than the depth of p-type partition region of an inner peripheral portion.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: September 1, 2015
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Takahiro Tamura, Yasuhiko Onishi, Mutsumi Kitamura
  • Patent number: 9089846
    Abstract: A media-agitation pulverizer is capable of creating a uniformized, stable helicoidal flow in a mixture of pulverizing media and a raw material slurry, thereby performing pulverization/dispersion uniformly with satisfactory energy efficiency. The media-agitation pulverizer includes a guide ring installed to radially divide a lower region of a pulverization chamber into an inner section and an annular outer section, whereby a flow of a mixture of a raw material slurry and pulverizing media is formed as a helicoidal flow including a secondary flow flowing through a circulation flow path with respect to the guide ring; and rotational-flow suppressing device is provided within the pulverization chamber and adapted to strengthen the secondary flow of the helicoidal flow, thereby stabilizing the helicoidal flow.
    Type: Grant
    Filed: July 23, 2012
    Date of Patent: July 28, 2015
    Assignee: ASHIZAWA FINETECH LTD.
    Inventors: Tsuyoshi Ishikawa, Shogo Iwasawa, Takahiro Tamura