Patents by Inventor Shunsaku UETA

Shunsaku UETA 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: 20230357957
    Abstract: A silicon carbide substrate has a first main surface and a second main surface opposite to the first main surface. The silicon carbide substrate includes screw dislocations and pits having a maximum diameter of 1 ?m or more and 10 ?m or less in a direction parallel to the first main surface. When the screw dislocations and the pits are observed in the first main surface, a percentage obtained by dividing a number of the pits by a number of the screw dislocations is 1% or less. A concentration of magnesium in the first main surface is less than 1×1011 atoms/cm2.
    Type: Application
    Filed: November 10, 2020
    Publication date: November 9, 2023
    Inventors: Kyoko OKITA, Tsubasa HONKE, Shunsaku UETA
  • Patent number: 11781246
    Abstract: In a case where a detector is positioned in a [11-20] direction, and where a first measurement region including a center of a main surface is irradiated with an X ray in a direction within ±15° relative to a [?1-120] direction, a ratio of a maximum intensity of a first intensity profile is more than or equal to 1500. In a case where the detector is positioned in a direction parallel to a [?1100] direction, and where the first measurement region is irradiated with an X ray in a direction within ±6° relative to a [1-100] direction, a ratio of a maximum intensity of a second intensity profile is more than or equal to 1500. An absolute value of a difference between maximum value and minimum value of energy at which the first intensity profile indicates a maximum value is less than or equal to 0.06 keV.
    Type: Grant
    Filed: November 23, 2022
    Date of Patent: October 10, 2023
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kyoko Okita, Takashi Sakurada, Eiryo Takasuka, Shunsaku Ueta, Sho Sasaki, Naoki Kaji, Hidehiko Mishima, Hirokazu Eguchi
  • Publication number: 20230081506
    Abstract: In a case where a detector is positioned in a [11-20] direction, and where a first measurement region including a center of a main surface is irradiated with an X ray in a direction within ±15° relative to a [?1-120] direction, a ratio of a maximum intensity of a first intensity profile is more than or equal to 1500. In a case where the detector is positioned in a direction parallel to a [?1100] direction, and where the first measurement region is irradiated with an X ray in a direction within ±6° relative to a [1-100] direction, a ratio of a maximum intensity of a second intensity profile is more than or equal to 1500. An absolute value of a difference between maximum value and minimum value of energy at which the first intensity profile indicates a maximum value is less than or equal to 0.06 keV.
    Type: Application
    Filed: November 23, 2022
    Publication date: March 16, 2023
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Kyoko OKITA, Takashi SAKURADA, Eiryo TAKASUKA, Shunsaku UETA, Sho SASAKI, Naoki KAJI, Hidehiko MISHIMA, Hirokazu EGUCHI
  • Patent number: 11535953
    Abstract: In a case where a detector is positioned in a [11-20] direction, and where a first measurement region including a center of a main surface is irradiated with an X ray in a direction within ±15° relative to a [?1-120] direction, a ratio of a maximum intensity of a first intensity profile is more than or equal to 1500. In a case where the detector is positioned in a direction parallel to a [?1100] direction, and where the first measurement region is irradiated with an X ray in a direction within ±6° relative to a [1-100] direction, a ratio of a maximum intensity of a second intensity profile is more than or equal to 1500. An absolute value of a difference between maximum value and minimum value of energy at which the first intensity profile indicates a maximum value is less than or equal to 0.06 keV.
    Type: Grant
    Filed: January 30, 2017
    Date of Patent: December 27, 2022
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kyoko Okita, Takashi Sakurada, Eiryo Takasuka, Shunsaku Ueta, Sho Sasaki, Naoki Kaji, Hidehiko Mishima, Hirokazu Eguchi
  • Publication number: 20220403550
    Abstract: A ratio obtained by dividing a number of pits by a number of screw dislocations is equal to or smaller than 1%. The first main surface has a surface roughness equal to or smaller than 0.15 nm. An absolute value of a difference between the first wave number and the second wave number is equal to or smaller than 0.2 cm?1, and an absolute value of a difference between the first full width at half maximum and the second full width at half maximum is equal to or smaller than 0.25 cm?1.
    Type: Application
    Filed: November 12, 2020
    Publication date: December 22, 2022
    Inventors: Kyoko OKITA, Tsubasa HONKE, Shunsaku UETA
  • Publication number: 20210054529
    Abstract: In a case where a detector is positioned in a [11-20] direction, and where a first measurement region including a center of a main surface is irradiated with an X ray in a direction within ±15° relative to a [?1-120] direction, a ratio of a maximum intensity of a first intensity profile is more than or equal to 1500. In a case where the detector is positioned in a direction parallel to a [?1100] direction, and where the first measurement region is irradiated with an X ray in a direction within ±6° relative to a [1-100] direction, a ratio of a maximum intensity of a second intensity profile is more than or equal to 1500. An absolute value of a difference between maximum value and minimum value of energy at which the first intensity profile indicates a maximum value is less than or equal to 0.06 keV.
    Type: Application
    Filed: January 30, 2017
    Publication date: February 25, 2021
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Kyoko OKITA, Takashi SAKURADA, Eiryo TAKASUKA, Shunsaku UETA, Sho SASAKI, Naoki KAJI, Hidehiko MISHIMA, Hirokazu EGUCHI
  • Patent number: 10361273
    Abstract: A silicon carbide substrate whose majority carrier density is 1×1017 cm?3 or greater is such that a standard deviation of minority carrier lifetime as obtained by ?-PCD analysis is 0.7 ns or less in an area other than an area within a distance of 5 mm from an outer perimeter of a main surface.
    Type: Grant
    Filed: October 12, 2016
    Date of Patent: July 23, 2019
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Naoki Kaji, Shunsaku Ueta, Tsutomu Hori, Shin Harada
  • Patent number: 10319821
    Abstract: A silicon carbide substrate includes a carbon-surface-side principal surface and a silicon-surface-side principal surface. The silicon carbide substrate has a diameter of 100 mm or greater and a thickness of 300 ?m or greater. An off angle of the carbon-surface-side principal surface and the silicon-surface-side principal surface relative to a {0001} plane is smaller than or equal to 4°. A nitrogen concentration in the carbon-surface-side principal surface is higher than a nitrogen concentration in the silicon-surface-side principal surface, and a difference in Raman peak shift between the carbon-surface-side principal surface and the silicon-surface-side principal surface is smaller than or equal to 0.2 cm?1.
    Type: Grant
    Filed: July 21, 2016
    Date of Patent: June 11, 2019
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shunsaku Ueta, Kyoko Okita, Shin Harada
  • Patent number: 10184191
    Abstract: Provided is a method for manufacturing a silicon carbide single crystal capable of easily separating a silicon carbide single crystal from a pedestal. The method includes the step of fixing a seed substrate to a pedestal with a stress buffer layer being interposed therebetween, the step of growing a silicon carbide single crystal on the seed substrate, the step of separating the silicon carbide single crystal from the pedestal at the stress buffer layer, and the step of removing a residue of the stress buffer layer adhering to the silicon carbide single crystal subjected to the step of separating.
    Type: Grant
    Filed: November 21, 2014
    Date of Patent: January 22, 2019
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Tsutomu Hori, Shunsaku Ueta, Akira Matsushima
  • Publication number: 20180254323
    Abstract: A silicon carbide substrate includes a carbon-surface-side principal surface and a silicon-surface-side principal surface. The silicon carbide substrate has a diameter of 100 mm or greater and a thickness of 300 ?m or greater. An off angle of the carbon-surface-side principal surface and the silicon-surface-side principal surface relative to a {0001} plane is smaller than or equal to 4°. A nitrogen concentration in the carbon-surface-side principal surface is higher than a nitrogen concentration in the silicon-surface-side principal surface, and a difference in Raman peak shift between the carbon-surface-side principal surface and the silicon-surface-side principal surface is smaller than or equal to 0.2 cm?1.
    Type: Application
    Filed: July 21, 2016
    Publication date: September 6, 2018
    Inventors: Shunsaku UETA, Kyoko OKITA, Shin HARADA
  • Publication number: 20180254324
    Abstract: A silicon carbide substrate whose majority carrier density is 1×1017 cm?3 or greater is such that a standard deviation of minority carrier lifetime as obtained by ?-PCD analysis is 0.7 ns or less in an area other than an area within a distance of 5 mm from an outer perimeter of a main surface.
    Type: Application
    Filed: October 12, 2016
    Publication date: September 6, 2018
    Inventors: Naoki KAJI, Shunsaku UETA, Tsutomu HORI, Shin HARADA
  • Patent number: 9777401
    Abstract: A method for producing a single crystal includes a step of placing a source material powder and a seed crystal within a crucible; and a step of growing a single crystal on the seed crystal. The crucible includes a peripheral wall part and a bottom part and a lid part that are connected to the peripheral wall part to close the openings of the peripheral wall part. In the step of growing the single crystal on the seed crystal, the crucible is disposed on a spacer so as to form a space starting directly below an outer surface of the bottom part, and the peripheral wall part and an auxiliary heating member that is placed so as to face the outer surface of the bottom part with the space therebetween are heated by induction heating to sublime the source material powder to cause recrystallization on the seed crystal.
    Type: Grant
    Filed: August 5, 2015
    Date of Patent: October 3, 2017
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shunsaku Ueta, Tsutomu Hori, Akira Matsushima
  • Patent number: 9777400
    Abstract: A method for producing a single crystal includes a step of placing a source material powder and a seed crystal within a crucible, and a step of growing a single crystal on the seed crystal. The crucible includes a peripheral wall part and a bottom part and a lid part that are connected to the peripheral wall part to close the openings of the peripheral wall part, the lid part having a holder that holds the seed crystal. The bottom part has a connection region connected to the peripheral wall part and a thick region that is thicker than the connection region and that surrounds a central axis passing through a center of gravity of orthogonal projection of the bottom part, the orthogonal projection being formed on a plane perpendicular to a growth direction of the single crystal, the central axis extending in the growth direction of the single crystal.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: October 3, 2017
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shunsaku Ueta, Tsutomu Hori, Akira Matsushima
  • Publication number: 20170152609
    Abstract: A method of manufacturing a silicon carbide substrate has the following steps. A silicon carbide source material is partially sublimated. After partially sublimating the silicon carbide source material, a seed substrate having a main surface is placed in a growth container. By sublimating the remainder of the silicon carbide source material in the growth container, a silicon carbide crystal grows on the main surface of the seed substrate. In this way, an increase of dislocations in the main surface of the seed substrate can be suppressed, thereby providing a method of manufacturing a silicon carbide substrate having few dislocations.
    Type: Application
    Filed: February 14, 2017
    Publication date: June 1, 2017
    Inventors: Shinsuke FUJIWARA, Taro NISHIGUCHI, Tsutomu HORI, Naoki OOI, Shunsaku UETA
  • Patent number: 9631296
    Abstract: A method of manufacturing a silicon carbide substrate has the following steps. A silicon carbide source material is partially sublimated. After partially sublimating the silicon carbide source material, a seed substrate having a main surface is placed in a growth container. By sublimating the remainder of the silicon carbide source material in the growth container, a silicon carbide crystal grows on the main surface of the seed substrate. In this way, an increase of dislocations in the main surface of the seed substrate can be suppressed, thereby providing a method of manufacturing a silicon carbide substrate having few dislocations.
    Type: Grant
    Filed: June 11, 2013
    Date of Patent: April 25, 2017
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Shinsuke Fujiwara, Taro Nishiguchi, Tsutomu Hori, Naoki Ooi, Shunsaku Ueta
  • Publication number: 20160340796
    Abstract: Provided is a method for manufacturing a silicon carbide single crystal capable of easily separating a silicon carbide single crystal from a pedestal. The method includes the step of fixing a seed substrate to a pedestal with a stress buffer layer being interposed therebetween, the step of growing a silicon carbide single crystal on the seed substrate, the step of separating the silicon carbide single crystal from the pedestal at the stress buffer layer, and the step of removing a residue of the stress buffer layer adhering to the silicon carbide single crystal subjected to the step of separating.
    Type: Application
    Filed: November 21, 2014
    Publication date: November 24, 2016
    Inventors: Tsutomu HORI, Shunsaku UETA, Akira MATSUSHIMA
  • Publication number: 20160040317
    Abstract: A method for producing a single crystal includes a step of placing a source material powder and a seed crystal within a crucible; and a step of growing a single crystal on the seed crystal. The crucible includes a peripheral wall part and a bottom part and a lid part that are connected to the peripheral wall part to close the openings of the peripheral wall part. In the step of growing the single crystal on the seed crystal, the crucible is disposed on a spacer so as to form a space starting directly below an outer surface of the bottom part, and the peripheral wall part and an auxiliary heating member that is placed so as to face the outer surface of the bottom part with the space therebetween are heated by induction heating to sublime the source material powder to cause recrystallization on the seed crystal.
    Type: Application
    Filed: August 5, 2015
    Publication date: February 11, 2016
    Inventors: Shunsaku UETA, Tsutomu HORI, Akira MATSUSHIMA
  • Publication number: 20160032487
    Abstract: A method for producing a single crystal includes a step of placing a source material powder and a seed crystal within a crucible, and a step of growing a single crystal on the seed crystal. The crucible includes a peripheral wall part and a bottom part and a lid part that are connected to the peripheral wall part to close the openings of the peripheral wall part, the lid part having a holder that holds the seed crystal. The bottom part has a connection region connected to the peripheral wall part and a thick region that is thicker than the connection region and that surrounds a central axis passing through a center of gravity of orthogonal projection of the bottom part, the orthogonal projection being formed on a plane perpendicular to a growth direction of the single crystal, the central axis extending in the growth direction of the single crystal.
    Type: Application
    Filed: July 24, 2015
    Publication date: February 4, 2016
    Inventors: Shunsaku UETA, Tsutomu HORI, Akira MATSUSHIMA
  • Publication number: 20160002820
    Abstract: A crucible has a bottom and a cylindrical side surface. In the crucible, a source material is sublimated to grow a single crystal. The crucible includes a third region configured to receive a source material, a second region extending from the third region in a direction away from the bottom, and a first region extending from the second region in a direction away from the bottom. The crucible includes a first wall and a second wall inside the side surface. The first wall surrounds the first region, the second wall surrounds the second region. The crucible includes a first chamber between the first wall and the side surface and a second chamber between the second wall and the side surface. The distance between horizontal opposite portions on the first wall is constant or increases as the horizontal opposite portions approach the bottom.
    Type: Application
    Filed: July 1, 2015
    Publication date: January 7, 2016
    Inventors: Tsutomu HORI, Shunsaku UETA, Akira MATSUSHIMA
  • Publication number: 20150225873
    Abstract: A method of manufacturing a silicon carbide substrate has the following steps. A silicon carbide source material is partially sublimated. After partially sublimating the silicon carbide source material, a seed substrate having a main surface is placed in a growth container. By sublimating the remainder of the silicon carbide source material in the growth container, a silicon carbide crystal grows on the main surface of the seed substrate. In this way, an increase of dislocations in the main surface of the seed substrate can be suppressed, thereby providing a method of manufacturing a silicon carbide substrate having few dislocations.
    Type: Application
    Filed: June 11, 2013
    Publication date: August 13, 2015
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shinsuke FUJIWARA, Taro NISHIGUCHI, Tsutomu HORI, Naoki OOI, Shunsaku UETA