Patents by Inventor Tomohiro Shonai

Tomohiro Shonai 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: 10988857
    Abstract: A SiC single crystal growth apparatus of an embodiment includes a seed crystal installation part in which a seed crystal is installable at a position thereof which faces a raw material; a guide member which extends from a periphery of the seed crystal installation part toward the raw material and guides crystal growth performed inside the guide member; and a heat-insulating material which is movable along an extension direction of the guide member on the outside of the guide member.
    Type: Grant
    Filed: April 19, 2019
    Date of Patent: April 27, 2021
    Assignee: SHOWA DENKO K.K.
    Inventors: Rimpei Kindaichi, Yoshishige Okuno, Tomohiro Shonai
  • Publication number: 20200318254
    Abstract: A SiC single crystal, including: a seed crystal; a first growth portion formed in a direction that is substantially orthogonal to a <0001> direction; a second growth portion formed in a direction that is substantially orthogonal to the <0001> direction and substantially orthogonal to the direction in which the first growth portion is formed; a third growth portion that is formed on a surface of the seed crystal opposite the first growth portion; and a fourth growth portion that is formed on a surface of the seed crystal opposite the second growth portion.
    Type: Application
    Filed: June 18, 2020
    Publication date: October 8, 2020
    Applicant: SHOWA DENKO K.K.
    Inventors: Tomohiro SHONAI, Masakazu Kobayashi, Masanori Yamada
  • Patent number: 10724152
    Abstract: This method for producing a SiC single crystal includes a first growth step of growing a crystal from a seed crystal in a direction that is substantially orthogonal to the <0001> direction, a second growth step of growing the crystal in a direction that is substantially orthogonal to the <0001> direction and substantially orthogonal to the direction of crystal growth in the first growth step, a third growth step of growing the crystal along the direction of crystal growth in the first growth step but in the opposite orientation to the orientation of crystal growth in the first growth step, and a fourth growth step of growing the crystal along the direction of crystal growth in the second growth step but in the opposite orientation to the orientation of crystal growth in the second growth step.
    Type: Grant
    Filed: November 29, 2016
    Date of Patent: July 28, 2020
    Assignee: SHOWA DENKO K.K.
    Inventors: Tomohiro Shonai, Masakazu Kobayashi, Masanori Yamada
  • Publication number: 20200181797
    Abstract: A crystal growing apparatus includes: a crucible which includes a main body portion, and a first portion having a radiation rate different from that of the main body portion, and is capable of controlling a temperature of a specific region inside during heating to a higher or lower temperature than that of the other regions; and a heating unit which is positioned on the outside of the crucible and is configured to heat the crucible by radiant heat, and the first portion is at a position where the crucible and a line segment connecting a heating center of the heating unit and the specific region intersect with each other.
    Type: Application
    Filed: December 4, 2019
    Publication date: June 11, 2020
    Applicant: SHOWA DENKO K.K.
    Inventors: Rimpei KINDAICHI, Yoshishige OKUNO, Tomohiro SHONAI
  • Publication number: 20200181796
    Abstract: A crystal growing apparatus includes: a crucible including a main body portion and a low radiation portion having a radiation rate lower than that of the main body portion; and a heating unit which is positioned on the outside of the crucible and is configured to heat the crucible by radiant heat, and the low radiation portion is provided on an outer surface of a first point which is a heating center, in a case where the crucible does not include the low radiation portion.
    Type: Application
    Filed: December 4, 2019
    Publication date: June 11, 2020
    Applicant: SHOWA DENKO K.K.
    Inventors: Rimpei KINDAICHI, Yoshishige OKUNO, Tomohiro SHONAI
  • Publication number: 20190330761
    Abstract: A SiC single crystal growth apparatus of an embodiment includes a seed crystal installation part in which a seed crystal is installable at a position thereof which faces a raw material; a guide member which extends from a periphery of the seed crystal installation part toward the raw material and guides crystal growth performed inside the guide member; and a heat-insulating material which is movable along an extension direction of the guide member on the outside of the guide member.
    Type: Application
    Filed: April 19, 2019
    Publication date: October 31, 2019
    Applicant: SHOWA DENKO K.K.
    Inventors: Rimpei KINDAICHI, Yoshishige OKUNO, Tomohiro SHONAI
  • Patent number: 10236338
    Abstract: A SiC single crystal seed of the present invention has a main surface with an offset angle of at least 2° but not more than 20° relative to the {0001} plane, and at least one sub-growth surface, wherein the sub-growth surface includes an initial facet formation surface that is on the offset upstream side of the main surface and has an inclination angle ? relative to the {0001} plane with an absolute value of less than 2° in any direction, and the initial facet formation surface has a screw dislocation starting point.
    Type: Grant
    Filed: April 20, 2016
    Date of Patent: March 19, 2019
    Assignee: SHOWA DENKO K.K.
    Inventors: Yuuki Furuya, Tomohiro Shonai, Yasushi Urakami, Itaru Gunjishima
  • Publication number: 20180355511
    Abstract: This method for producing a SiC single crystal includes a first growth step of growing a crystal from a seed crystal in a direction that is substantially orthogonal to the <0001> direction, a second growth step of growing the crystal in a direction that is substantially orthogonal to the <0001> direction and substantially orthogonal to the direction of crystal growth in the first growth step, a third growth step of growing the crystal along the direction of crystal growth in the first growth step but in the opposite orientation to the orientation of crystal growth in the first growth step, and a fourth growth step of growing the crystal along the direction of crystal growth in the second growth step but in the opposite orientation to the orientation of crystal growth in the second growth step.
    Type: Application
    Filed: November 29, 2016
    Publication date: December 13, 2018
    Applicant: SHOWA DENKO K.K.
    Inventors: Tomohiro SHONAI, Masakazu KOBAYASHI, Masanori YAMADA
  • Publication number: 20180130872
    Abstract: A SiC single crystal seed of the present invention has a main surface with an offset angle of at least 2° but not more than 20° relative to the {0001} plane, and at least one sub-growth surface, wherein the sub-growth surface includes an initial facet formation surface that is on the offset upstream side of the main surface and has an inclination angle ? relative to the {0001} plane with an absolute value of less than 2° in any direction, and the initial facet formation surface has a screw dislocation starting point.
    Type: Application
    Filed: April 20, 2016
    Publication date: May 10, 2018
    Applicant: SHOWA DENKO K.K.
    Inventors: Yuuki FURUYA, Tomohiro SHONAI, Yasushi URAKAMI, Itaru GUNJISHIMA
  • Publication number: 20120015799
    Abstract: A method for producing a sapphire single crystal, which includes: performing a sapphire single crystal growth step wherein a sapphire ingot, which is an ingot of sapphire single crystal, is produced (step 101); performing a subsequent ingot heating step wherein the sapphire ingot obtained in the sapphire single crystal growth step is heated (step 102); and performing a subsequent ingot processing step wherein the heated sapphire ingot is machined (step 103). In the ingot heating step, the sapphire ingot is heated in an atmosphere in which the oxygen concentration is increased to be equal to or higher than that in the air. Consequently, crystal defects in the ingot of sapphire single crystal produced by crystal growth are removed and the occurrence of cracks in the sapphire ingot during machining of the sapphire ingot is suppressed, thereby improving the yield of sapphire products obtained from the ingot.
    Type: Application
    Filed: June 25, 2010
    Publication date: January 19, 2012
    Applicant: SHOWA DENKO K.K.
    Inventor: Tomohiro Shonai
  • Publication number: 20110253031
    Abstract: Following steps are implemented: a melting step in which aluminum oxide within a crucible is melted to obtain an aluminum melt; a shoulder-portion formation step in which a seed crystal brought into contact with the aluminum melt is pulled up to thereby form a shoulder portion below the seed crystal; a body-portion formation step in which single-crystal sapphire is pulled up from the melt to form a body portion; and a tail-portion formation step in which a mixed gas including oxygen and an inert gas and having an oxygen concentration set at not less than 1.0 vol % nor more than 5.0 vol % is supplied while the single-crystal sapphire is pulled away from the melt to form a tail portion. Thus, when single-crystal sapphire is obtained by growth from a melt of aluminum oxide, formation of a protrusion in the tail portion of the single-crystal sapphire is more effectively inhibited.
    Type: Application
    Filed: December 16, 2009
    Publication date: October 20, 2011
    Applicant: SHOWA DENKO K.K.
    Inventor: Tomohiro Shonai
  • Publication number: 20110247547
    Abstract: Following steps are implemented: a melting step in which aluminum oxide within a crucible placed in a chamber is melted to obtain an aluminum melt; a shoulder-portion formation step in which a seed crystal brought into contact with the aluminum melt is pulled up to thereby form a shoulder portion below the seed crystal; and a body-portion formation step in which a mixed gas including oxygen and an inert gas and having an oxygen concentration set at not less than 0.6 vol % nor more than 3.0 vol % is supplied to the inside of the chamber while single-crystal sapphire is pulled up from the melt, thereby forming a body portion. Thus, when single-crystal sapphire is obtained by crystal growth from a melt of aluminum oxide, air bubbles are more effectively inhibited from coming into the single-crystal sapphire.
    Type: Application
    Filed: December 16, 2009
    Publication date: October 13, 2011
    Inventor: Tomohiro Shonai
  • Publication number: 20100028240
    Abstract: A method for producing an SiC single crystal comprises providing a low temperature region and a high temperature region in a crystal growth crucible (6); disposing a seed crystal substrate formed of an SiC single crystal in the low temperature region of the crystal growth crucible; disposing an SiC raw material in the high temperature region; and depositing a sublimation gas that sublimes from the SiC raw material on the seed crystal substrate to grow the SiC single crystal. A material used in the crucible member where the seed crystal is disposed is a material having a room-temperature linear expansion coefficient that differs from that of SiC by 1.0×10?6/K or less, and the crucible member where the seed crystal is disposed is made of Sic.
    Type: Application
    Filed: October 4, 2007
    Publication date: February 4, 2010
    Inventors: Tomohiro Shonai, Hisao Kogoi, Yasuyuki Sakaguchi
  • Patent number: 6937630
    Abstract: To provide a laser oscillation method and a laser device, which use a laser medium such as an Nd:GdVO4 crystal to which neodymium is doped in high concentration exceeding 1% in atomicity ratio, the laser medium comprised of the gadolinium-vanadate crystal to which neodymium as laser active ion is doped by a floating zone method such that concentration becomes exceeding 1% in atomicity ratio.
    Type: Grant
    Filed: September 10, 2002
    Date of Patent: August 30, 2005
    Assignees: Riken, NEC Tokin Corporation, Megaopto Co., Ltd.
    Inventors: Satoshi Wada, Takayo Ogawa, Hideo Tashiro, Hiroshi Machida, Mikio Higuchi, Kohei Kodaira, Tomohiro Shonai
  • Publication number: 20030147444
    Abstract: To provide a laser oscillation method and a laser device, which use a laser medium such as an Nd:GdVO4 crystal to which neodymium is doped in high concentration exceeding 1% in atomicity ratio, the laser medium comprised of the gadolinium-vanadate crystal to which neodymium as laser active ion is doped by a floating zone method such that concentration becomes exceeding 1% in atomicity ratio.
    Type: Application
    Filed: September 10, 2002
    Publication date: August 7, 2003
    Inventors: Satoshi Wada, Takayo Ogawa, Hideo Tashiro, Hiroshi Machida, Mikio Higuchi, Kohei Kodaira, Tomohiro Shonai