Patents by Inventor Yohei Fujikawa

Yohei Fujikawa 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: 11459669
    Abstract: A SiC ingot includes a core portion; and a surface layer that is formed on a plane of the core portion in a growing direction, and a coefficient of linear thermal expansion of the surface layer is smaller than a coefficient of linear thermal expansion of the core portion.
    Type: Grant
    Filed: December 18, 2018
    Date of Patent: October 4, 2022
    Assignee: SHOWA DENKO K.K.
    Inventors: Rimpei Kindaichi, Yohei Fujikawa, Yoshishige Okuno
  • Patent number: 11454599
    Abstract: A thermal conductivity measuring device includes a sample container that has a plurality of storage sections; a drive unit that is configured to move the plurality of storage sections of the sample container; and a radiation thermometer that is configured to measure the temperature of a predetermined position of the sample container.
    Type: Grant
    Filed: September 4, 2019
    Date of Patent: September 27, 2022
    Assignee: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Patent number: 11453958
    Abstract: The present invention provides a heat-insulating shield member, wherein the heat-insulating shield member is arranged and used between a SiC source housing (3) and a substrate support (4) in a single crystal manufacturing apparatus (10), wherein the single crystal manufacturing apparatus (10) comprises a crystal growth container (2) and a heating member (5) arranged on an outer periphery of the crystal growth container (2), wherein the crystal growth container (2) includes the SiC source housing (3) disposed at a lower portion of the apparatus, and the substrate support (4) which is arranged above the SiC source housing (3) and supports a substrate (S) used for crystal growth so as to face the SiC source housing (3), and wherein the single crystal manufacturing apparatus (10) is configured to grow a single crystal (W) from a SiC source (M) on the substrate (S) by sublimating the SiC source (M) from the SiC source housing (3).
    Type: Grant
    Filed: April 19, 2019
    Date of Patent: September 27, 2022
    Assignee: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Patent number: 11453959
    Abstract: A crystal growth apparatus according to the present embodiment includes a crucible, a heater which is installed on an outward side of the crucible and surrounds the crucible, and a coil which is installed on an outward side of the heater and surrounds the heater, in which an inner surface of the heater on the crucible side includes a first region, and a second region which is further away from an outer side surface of the crucible than the first region is.
    Type: Grant
    Filed: October 16, 2020
    Date of Patent: September 27, 2022
    Assignee: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Patent number: 11427927
    Abstract: A SiC single crystal manufacturing apparatus of the present invention includes a growth container having a growth space in which a SiC single crystal is grown in a first direction and a heat insulating material which covers the growth container and includes a plurality of units, and the plurality of units include a first unit and a second unit having at least a thermal conductivity different from that of the first unit, and the first unit includes a container made of at least one of graphite and a metal carbide and a filler filled into the container in a replaceable manner.
    Type: Grant
    Filed: December 12, 2019
    Date of Patent: August 30, 2022
    Assignee: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Patent number: 11408841
    Abstract: A thermal conductivity measuring device includes a sample container that has a plurality of storage sections; a drive unit that is configured to move the plurality of storage sections of the sample container; and a radiation thermometer that is configured to measure the temperature of a predetermined position of the sample container.
    Type: Grant
    Filed: September 4, 2019
    Date of Patent: August 9, 2022
    Assignee: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Patent number: 11326274
    Abstract: Provided is a single crystal growth crucible including a first housing and a second housing, in which a fitting portion between the first housing and the second housing has a first protruding portion, which is provided by protruding inner wall side of the first housing toward the second housing, and a second protruding portion, which is provided by protruding outer wall side of the second housing toward the first housing and covers an outer circumferential surface of the first protruding portion, the first protruding portion is formed such that an outer diameter of a tip portion thereof is larger than that of a base portion thereof in the protruding direction, and the second protruding portion is formed such that an inner diameter of a tip portion thereof is smaller than that of a base portion thereof in the protruding direction, the outer diameter of the tip portion of the first protruding portion is equal to or smaller than the inner diameter of the tip portion of the second protruding portion at room tempe
    Type: Grant
    Filed: June 24, 2020
    Date of Patent: May 10, 2022
    Assignee: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Patent number: 11306412
    Abstract: A SiC single crystal manufacturing apparatus of the present invention is a SiC single crystal manufacturing apparatus that manufactures a SiC single crystal by performing crystal growth on a growth surface of a seed crystal disposed inside a crucible, and the crucible 1 is able to accommodate a raw material M for a SiC single crystal therein, and includes a crucible lower portion 1A and a crucible upper portion 1B, the crucible lower portion including a bottom portion 1Aa and a side portion 1Ab, and the crucible upper portion including a top portion 1Ba provided with a seed crystal installation portion 1Bc for installing a seed crystal SD and a side portion 1Bb.
    Type: Grant
    Filed: November 12, 2019
    Date of Patent: April 19, 2022
    Assignee: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Patent number: 11261541
    Abstract: A shielding member placed between a SiC source loading portion and a crystal installation portion in an apparatus for single crystal growth, including a crystal growth container including the loading portion which accommodates a SiC source in an inner bottom portion; a crystal installation portion facing the loading portion, and a heating unit configured to heat the crystal growth container. The device grows a single crystal of the SiC source on a crystal installed on the crystal installation portion by sublimating the SiC source from the loading portion. The shielding member includes a plurality of shielding plates, wherein each area of the plurality of shielding plates is 40% or less of a base area of the crystal growth container. When the SiC source loading portion is filled with a SiC source, a shielding ratio provided by a projection surface of the plurality of shielding plates is 0.5 or more.
    Type: Grant
    Filed: August 6, 2019
    Date of Patent: March 1, 2022
    Assignee: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Patent number: 11111599
    Abstract: The present invention provides a single crystal growth method capable of suppressing the recrystallization of the raw material gas subjected to sublimation on the surface of the raw material, and suppressing the generation of different polytypes in the crystal growing single crystal. The single crystal growth method is carried out in a crucible comprising an inner bottom for providing a raw material and a crystal mounting part facing the inner bottom. The method comprises in the following order: providing the raw material in the inner bottom; covering at least a part of a surface of the raw material with a metal carbide powder in a plan view from the crystal mounting part; and growing a single crystal disposed in the crystal mounting part by sublimating the raw material by heating.
    Type: Grant
    Filed: September 4, 2019
    Date of Patent: September 7, 2021
    Assignee: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Publication number: 20210246572
    Abstract: A SiC single crystal, wherein difference between the curving amount of the atomic arrangement surface on the cut surface cut along the <1-100> direction through the center in plan view and the curving amount of the atomic arrangement surface on the cut surface cut along the <11-20> direction that passes through the center of view and is perpendicular to the <1-100> direction is 60 ?m or less.
    Type: Application
    Filed: August 13, 2019
    Publication date: August 12, 2021
    Applicants: SHOWA DENKO K.K., DENSO CORPORATION
    Inventors: Shunsuke NOGUCHI, Yohei FUJIKAWA, Hidetaka TAKABA
  • Patent number: 11078598
    Abstract: A silicon carbide single crystal is grown by a method comprising: a single crystal growth step of growing a silicon carbide single crystal so as to not close a gap between a side surface of the silicon carbide single crystal growing on a silicon carbide seed crystal, and an inner-side surface of a guide member and a crystal deposited on the inner-side surface of the guide member; a crystal growth termination step of terminating crystal growth by temperature lowering; and a gap enlargement step, performed between the single crystal growth step and the crystal growth termination step, of enlarging the gap by maintaining a difference, Pin?Pout, between partial pressure Pin of Si2C in a source gas in the vicinity of an inlet of the gap and partial pressure Pout of Si2C in a source gas in the vicinity of an outlet of the gap at 0.18 torr or less.
    Type: Grant
    Filed: December 15, 2017
    Date of Patent: August 3, 2021
    Assignee: SHOWA DENKO K.K.
    Inventors: Yohei Fujikawa, Hidetaka Takaba
  • Publication number: 20210230768
    Abstract: A method for producing a silicon carbide single crystal according to the present invention is a method for producing a silicon carbide single crystal in which a single crystal of silicon carbide is grown on a silicon carbide seed crystal by using a guide member, the method comprising: a single crystal growth step of growing a silicon carbide single crystal in a manner so as to not close a gap between a side surface of the silicon carbide single crystal growing on the silicon carbide seed crystal, and an inner-side surface of the guide member and a crystal deposited on the inner-side surface of the guide member; a crystal growth termination step of terminating crystal growth by lowering the temperature; and a gap enlargement step, performed between the single crystal growth step and the crystal growth termination step, of enlarging the gap by maintaining a difference, Pin-Pout, between a partial pressure Pin of Si2C in a source gas in the vicinity of an inlet of the gap and a partial pressure Pout of Si2C in a
    Type: Application
    Filed: December 15, 2017
    Publication date: July 29, 2021
    Applicant: SHOWA DENKO K.K.
    Inventors: Yohei FUJIKAWA, Hidetaka TAKABA
  • Publication number: 20210189596
    Abstract: A SiC single crystal, wherein an atomic arrangement surface on the cut surface cut along the <1-100> direction through the center in plan view and an atomic arrangement surface on the cut surface cut along the <11-20> direction that passes through the center of the plan view and is perpendicular to the <1-100> direction are curved in the same direction.
    Type: Application
    Filed: August 13, 2019
    Publication date: June 24, 2021
    Applicant: SHOWA DENKO K.K.
    Inventors: Shunsuke NOGUCHI, Yohei FUJIKAWA, Hidetaka TAKABA
  • Patent number: 11041257
    Abstract: A shielding member includes a plurality of shielding plates, in which the plurality of shielding plates are arranged without gaps therebetween in a plan view from a crystal installation part, and the shielding member is disposed between a source material accommodation part and the crystal installation part, in an apparatus for growing single crystals, wherein the apparatus includes a container for crystal growth that has the source material accommodation part at an inner bottom part, and has the crystal installation part that faces the source material accommodation part, and includes a heating part that is configured to heat the container for crystal growth, in which a single crystal of the source material is grown on a crystal installed in the crystal installation part by subliming the source material from the source material accommodation part.
    Type: Grant
    Filed: April 23, 2019
    Date of Patent: June 22, 2021
    Assignee: SHOWA DENKO K.K.
    Inventors: Yoshiteru Hosaka, Yohei Fujikawa
  • Patent number: 11008670
    Abstract: A manufacturing method of a SiC ingot includes a crystal growth step of growing a crystal on a principal plane having an offset angle with respect to a {0001} plane, in which, at least in a latter half growth step of the crystal growth step, after the crystal in the crystal growth step grows 7 mm or more from the principal plane, and in which, the crystal is grown by setting an acute angle, between the {0001} plane and an inclined plane which is perpendicular to a cut section cut along an offset direction and passes through both a center of a crystal growth surface and an offset downstream end portion of the crystal growth surface, to be equal to or more than an angle smaller than an offset angle by 2° and equal to or less than 8.6°.
    Type: Grant
    Filed: December 22, 2017
    Date of Patent: May 18, 2021
    Assignee: SHOWA DENKO K.K.
    Inventors: Yohei Fujikawa, Hideyuki Uehigashi
  • Publication number: 20210130981
    Abstract: A crystal growth apparatus according to the present embodiment includes a crucible, a heater which is installed on an outward side of the crucible and surrounds the crucible, and a coil which is installed on an outward side of the heater and surrounds the heater, in which an inner surface of the heater on the crucible side includes a first region, and a second region which is further away from an outer side surface of the crucible than the first region is.
    Type: Application
    Filed: October 16, 2020
    Publication date: May 6, 2021
    Applicant: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Patent number: 10995418
    Abstract: A shielding member, wherein the shielding member is formed of at least one of structure which has a non-flat plate shape having an inclined surface, and the inclined surface is located on a side of a substrate support part when the shielding member is disposed in a single crystal growth device, wherein the single crystal growth device comprising: a crystal growth container; a source storage part that is positioned at a lower inner part of the crystal growth container; the substrate support part, wherein the support part is disposed above the source storage part and supports a substrate to make the substrate face the source storage part; and a heating device that is disposed on an outer circumference of the crystal growth container, wherein the shielding member is disposed between the source storage part and the substrate support part, and wherein a single crystal of a source is grown on the substrate by sublimating the source from the source storage part.
    Type: Grant
    Filed: May 8, 2019
    Date of Patent: May 4, 2021
    Assignee: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Patent number: 10907272
    Abstract: The present invention provides a method including: a temperature raising step of raising a temperature in a crystal growing furnace with a silicon carbide raw material and a silicon carbide seed crystal arranged therein to a crystal growing temperature; a single crystal growing step of maintaining the crystal growing temperature and causing a silicon carbide single crystal to grow on the silicon carbide seed crystal; and a temperature lowering step of lowering the temperature in the crystal growing furnace from the crystal growing temperature to stop growth of the silicon carbide single crystal, in which the method further comprises, between the single crystal growing step and the temperature lowering step, a temperature lowering preparation step of maintaining the temperature in the crystal growing furnace at the crystal growing temperature and causing concentration of nitrogen gas in the crystal growing furnace to increase to be higher than concentration of nitrogen gas in the temperature raising step and i
    Type: Grant
    Filed: December 17, 2018
    Date of Patent: February 2, 2021
    Assignee: SHOWA DENKO K.K.
    Inventor: Yohei Fujikawa
  • Publication number: 20200407872
    Abstract: Provided is a single crystal growth crucible including a first housing and a second housing, in which a fitting portion between the first housing and the second housing has a first protruding portion, which is provided by protruding inner wall side of the first housing toward the second housing, and a second protruding portion, which is provided by protruding outer wall side of the second housing toward the first housing and covers an outer circumferential surface of the first protruding portion, the first protruding portion is formed such that an outer diameter of a tip portion thereof is larger than that of a base portion thereof in the protruding direction, and the second protruding portion is formed such that an inner diameter of a tip portion thereof is smaller than that of a base portion thereof in the protruding direction, the outer diameter of the tip portion of the first protruding portion is equal to or smaller than the inner diameter of the tip portion of the second protruding portion at room tempe
    Type: Application
    Filed: June 24, 2020
    Publication date: December 31, 2020
    Applicant: SHOWA DENKO K.K.
    Inventor: Yohei FUJIKAWA