Patents by Inventor Hidetaka TAKABA

Hidetaka TAKABA 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: 20210047750
    Abstract: A seed crystal for single crystal 4H-SiC growth of the present invention is a disk-shaped seed crystal for single crystal 4H-SiC growth having a diameter of more than 150 mm and having a thickness within a range of more than or equal to 1 mm and less than or equal to 0.03 times of the diameter, in which one surface on which the single crystal 4H-SiC is grown is a mirror surface and an Ra of the other surface is more than 10 nm, and an absolute value of magnitude of waviness in a state where the seed crystal is freely deformed so that an internal stress distribution is reduced is less than or equal to 12 ?m.
    Type: Application
    Filed: December 21, 2018
    Publication date: February 18, 2021
    Applicants: SHOWA DENKO K.K., DENSO CORPORATION
    Inventors: Takanori KIDO, Masatake NAGAYA, Hidetaka TAKABA
  • Publication number: 20200020777
    Abstract: In a SiC wafer, a difference between a threading dislocation density of threading dislocations exposed on a first surface and a threading dislocation density of threading dislocations exposed on a second surface is 10% or less of the threading dislocation density of the surface with a higher threading dislocation density among the first surface and the second surface, and 90% or more of the threading dislocations exposed on the surface with a higher threading dislocation density among the first surface and the second surface extend to the surface with a lower threading dislocation density.
    Type: Application
    Filed: December 22, 2017
    Publication date: January 16, 2020
    Applicants: SHOWA DENKO K.K., DENSO CORPORATION
    Inventors: Yohei FUJIKAWA, Hidetaka TAKABA
  • Publication number: 20190301051
    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: Application
    Filed: December 15, 2017
    Publication date: October 3, 2019
    Applicant: SHOWA DENKO K.K.
    Inventors: Yohei FUJIKAWA, Hidetaka TAKABA