Patents by Inventor Kimiyoshi Koshi

Kimiyoshi Koshi 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: 10196756
    Abstract: A ?-Ga2O3-based single-crystal substrate includes a ?-Ga2O3-based single crystal, and a principal surface being a plane parallel to a b-axis of the ?-Ga2O3-based single crystal. A maximum value of ?? on an arbitrary straight line on the principal surface that passes through a center of the principal surface is not more than 0.7264. The ?? is a difference between a maximum value and a minimum value of values obtained by subtracting ?a from ?s at each of measurement positions, where ?s represents an angle defined by an X-ray incident direction and the principal surface at a peak position of an X-ray rocking curve on the straight line and ?a represents an angle on an approximated straight line obtained by using least-squares method to linearly approximate a curve representing a relationship between the ?s and the measurement positions thereof.
    Type: Grant
    Filed: June 29, 2015
    Date of Patent: February 5, 2019
    Assignees: TAMURA CORPORATION, KOHA CO., LTD.
    Inventors: Shinya Watanabe, Kimiyoshi Koshi, Yu Yamaoka, Kazuyuki Iizuka, Masaru Takizawa, Takekazu Masui
  • Patent number: 9926646
    Abstract: A method for growing a ?-Ga2O3-based single crystal, can provide a plate-shaped ?-Ga2O3-based single crystal having high crystal quality. In one embodiment, a method for growing a ?-Ga2O3-based single crystal employing an EFG method is provided, the method including: bringing a plate-shaped seed crystal into contact with a Ga2O3-based melt, wherein the plate-shaped seed crystal includes a ?-Ga2O3-based single crystal having a defect density of not more than 5×105 /cm2 in the whole region; and pulling up the seed crystal to grow a ?-Ga2O3-based single crystal.
    Type: Grant
    Filed: October 9, 2013
    Date of Patent: March 27, 2018
    Assignees: TAMURA CORPORATION, KOHA CO., LTD.
    Inventors: Shinya Watanabe, Daiki Wakimoto, Kazuyuki Iizuka, Kimiyoshi Koshi, Takekazu Masui
  • Patent number: 9915009
    Abstract: Provided is one embodiment which is a method for growing a ?-Ga2O3-based single crystal including contacting a flat plate-shaped seed crystal with a Ga2O3-based melt, and pulling up the seed crystal such that a flat plate-shaped ?-Ga2O3-based single crystal having a principal surface which intersects a surface is grown without inheriting a crystal information of a vaporized material of the Ga2O3-based melt adhered to the principal surface of the seed crystal, wherein when growing the ?-Ga2O3-based single crystal, a shoulder of the ?-Ga2O3-based single crystal is widened in a thickness direction (t) thereof.
    Type: Grant
    Filed: May 2, 2014
    Date of Patent: March 13, 2018
    Assignees: TAMURA CORPORATION, KOHA CO., LTD.
    Inventors: Kimiyoshi Koshi, Shinya Watanabe
  • Patent number: 9915010
    Abstract: Provided is one embodiment which is a method for growing a ?-Ga2O3-based single crystal which uses the EFG method and includes raising a Ga2O3 melt inside a crucible up to a die opening via a die slit such that a seed crystal is contacted with the Ga2O3-based melt in the opening of the die with a horizontal position of the seed crystal shifted in a width direction (W) from a center in the width direction (W) of the die, and pulling up the seed crystal contacting the Ga2O3-based melt so as to grown a ?-Ga2O3 single crystal.
    Type: Grant
    Filed: May 2, 2014
    Date of Patent: March 13, 2018
    Assignees: TAMURA CORPORATION, KOHA CO., LTD.
    Inventors: Kimiyoshi Koshi, Takekazu Masui, Masaru Takizawa
  • Patent number: 9903045
    Abstract: A method for growing a ?-Ga2O3-based single crystal, can provide a plate-shaped ?-Ga2O3-based single crystal having high crystal quality. In one embodiment, a method for growing a ?-Ga2O3-based single crystal employing an EFG method is provided, the method including: bringing a plate-shaped seed crystal into contact with a Ga2O3-based melt, wherein the plate-shaped seed crystal includes a ?-Ga2O3-based single crystal having a defect density of not more than 5×105 /cm2 in the whole region; and pulling up the seed crystal to grow a ?-Ga2O3-based single crystal.
    Type: Grant
    Filed: October 9, 2013
    Date of Patent: February 27, 2018
    Assignees: TAMURA CORPORATION, KOHA CO., LTD.
    Inventors: Shinya Watanabe, Daiki Wakimoto, Kazuyuki Iizuka, Kimiyoshi Koshi, Takekazu Masui
  • Publication number: 20170152610
    Abstract: A ?-Ga2O3-based single-crystal substrate includes a ?-Ga2O3-based single crystal, and a principal surface being a plane parallel to a b-axis of the ?-Ga2O3-based single crystal. A maximum value of ?? on an arbitrary straight line on the principal surface that passes through a center of the principal surface is not more than 0.7264. The ?? is a difference between a maximum value and a minimum value of values obtained by subtracting ?a from ?s at each of measurement positions, where ?s represents an angle defined by an X-ray incident direction and the principal surface at a peak position of an X-ray rocking curve on the straight line and ?a represents an angle on an approximated straight line obtained by using least-squares method to linearly approximate a curve representing a relationship between the ?s and the measurement positions thereof.
    Type: Application
    Filed: June 29, 2015
    Publication date: June 1, 2017
    Applicants: TAMURA CORPORATION, KOHA CO., LTD.
    Inventors: Shinya WATANABE, Kimiyoshi KOSHI, Yu YAMAOKA, Kazuyuki IIZUKA, Masaru TAKIZAWA, Takekazu MASUI
  • Publication number: 20170137965
    Abstract: Provided is a gallium oxide substrate which has less linear pits. Obtained is a gallium oxide substrate wherein the average density of linear pits in a single crystal surface is 1,000 pits/cm2 or less.
    Type: Application
    Filed: July 1, 2015
    Publication date: May 18, 2017
    Applicants: TAMURA CORPORATION, KOHA CO., LTD.
    Inventors: Kimiyoshi KOSHI, Shinya WATANABE, Yu YAMAOKA, Makoto WATANABE
  • Patent number: 9431489
    Abstract: A ?-Ga2O3-based single crystal substrate includes an average dislocation density of less than 7.31×104 cm?2. The average dislocation density may be not more than 6.14×104 cm?2. The substrate may further include a main surface including a plane orientation of (?201), (101) or (001). The substrate may be free from any twinned crystal.
    Type: Grant
    Filed: February 27, 2015
    Date of Patent: August 30, 2016
    Assignees: TAMURA CORPORATION, KOHA CO., LTD.
    Inventors: Kimiyoshi Koshi, Shinya Watanabe, Masaru Takizawa, Yu Yamaoka, Makoto Watanabe, Takekazu Masui
  • Patent number: 9349915
    Abstract: A ?-Ga2O3-based single crystal substrate includes a ?-Ga2O3-based single crystal. The ?-Ga2O3-based single crystal includes a full width at half maximum of an x-ray rocking curve of less than 75 seconds.
    Type: Grant
    Filed: February 26, 2015
    Date of Patent: May 24, 2016
    Assignees: TAMURA CORPORATION, KOHA CO., LTD.
    Inventors: Kimiyoshi Koshi, Shinya Watanabe, Masaru Takizawa, Yu Yamaoka, Daiki Wakimoto, Makoto Watanabe
  • Publication number: 20160122899
    Abstract: Provided is one embodiment which is a method for growing a ?-Ga2O3-based single crystal including contacting a flat plate-shaped seed crystal with a Ga2O3-based melt, and pulling up the seed crystal such that a flat plate-shaped ?-Ga2O3-based single crystal having a principal surface which intersects a surface is grown without inheriting a crystal information of a vaporized material of the Ga2O3-based melt adhered to the principal surface of the seed crystal, wherein when growing the ?-Ga2O3-based single crystal, a shoulder of the ?-Ga2O3-based single crystal is widened in a thickness direction (t) thereof.
    Type: Application
    Filed: May 2, 2014
    Publication date: May 5, 2016
    Applicants: KOHA CO., LTD., TAMURA CORPORATION
    Inventors: Kimiyoshi KOSHI, Shinya WATANABE
  • Publication number: 20160115621
    Abstract: Provided is one embodiment which is a method for growing a ?-Ga2O3-based single crystal which uses the EFG method and includes raising a Ga2O3 melt inside a crucible up to a die opening via a die slit such that a seed crystal is contacted with the Ga2O3-based melt in the opening of the die with a horizontal position of the seed crystal shifted in a width direction (W) from a center in the width direction (W) of the die, and pulling up the seed crystal contacting the Ga2O3-based melt so as to grown a ?-Ga2O3 single crystal.
    Type: Application
    Filed: May 2, 2014
    Publication date: April 28, 2016
    Applicants: TAMURA CORPORATION, KOHA CO., LTD.
    Inventors: Kimiyoshi KOSHI, Takekazu MASUI, Masaru TAKIZAWA
  • Publication number: 20150380500
    Abstract: A Ga2O3-based single crystal substrate includes a main surface including BOW of not less than ?13 ?m and not more than 0 ?m. The main surface may further include WARP of not more than 25 ?m. The main surface may further include TTV of not more than 10 ?m.
    Type: Application
    Filed: February 27, 2015
    Publication date: December 31, 2015
    Inventors: Takekazu MASUI, Kimiyoshi KOSHI, Kei DOIOKA, Yu YAMAOKA
  • Publication number: 20150380501
    Abstract: A ?-Ga2O3-based single crystal substrate includes an average dislocation density of less than 7.31×104 cm?2. The average dislocation density may be not more than 6.14×104 cm?2. The substrate may further include a main surface including a plane orientation of (?201), (101) or (001). The substrate may be free from any twinned crystal.
    Type: Application
    Filed: February 27, 2015
    Publication date: December 31, 2015
    Inventors: Kimiyoshi KOSHI, Shinya Watanabe, Masaru Takizawa, Yu Yamaoka, Makoto Watanabe, Takekazu Masui
  • Publication number: 20150308012
    Abstract: A method for growing a ?-Ga2O3-based single crystal, can provide a plate-shaped ?-Ga2O3-based single crystal having high crystal quality. In one embodiment, a method for growing a ?-Ga2O3-based single crystal employing an EFG method is provided, the method including: bringing a plate-shaped seed crystal into contact with a Ga2O3-based melt, wherein the plate-shaped seed crystal includes a ?-Ga2O3-based single crystal having a defect density of not more than 5×105/cm2 in the whole region; and pulling up the seed crystal to grow a ?-Ga2O3-based single crystal.
    Type: Application
    Filed: October 9, 2013
    Publication date: October 29, 2015
    Inventors: Shinya WATANABE, Daiki WAKIMOTO, Kazuyuki IIZUKA, Kimiyoshi KOSHI, Takekazu MASUI
  • Publication number: 20150249185
    Abstract: A ?-Ga2O3-based single crystal substrate includes a ?-Ga2O3-based single crystal. The ?-Ga2O3-based single crystal includes a full width at half maximum of an x-ray rocking curve of less than 75 seconds.
    Type: Application
    Filed: February 26, 2015
    Publication date: September 3, 2015
    Inventors: Kimiyoshi KOSHI, Shinya Watanabe, Masaru Takizawa, Yu Yamaoka, Daiki Wakimoto, Makoto Watanabe
  • Publication number: 20150155356
    Abstract: Provided is a semiconductor laminate structure including a Ga2O3 substrate and a nitride semiconductor layer with high crystal quality on the Ga2O3 substrate, and also provided is a semiconductor element including this semiconductor laminate structure. In one embodiment, this semiconductor laminate structure includes a ?-Ga2O3 substrate including ?-Ga2O3 crystal and a principal surface inclined from a (?201) surface to a [102] direction nd a nitride semiconductor layer including AlxGayInzN (0?x?1, 0?y?1, 0?z?1, x+y+z=1) crystal formed by epitaxial crystal growth on the principal surface of the ?-Ga2O3 substrate.
    Type: Application
    Filed: May 27, 2013
    Publication date: June 4, 2015
    Applicants: TAMURA CORPORATIO9N, KOHA CO., LTD
    Inventors: Kazuyuki Iizuka, Shinya Watanabe, Kimiyoshi Koshi, Daiki Wakimoto, Yoshihiro Yamashita, Shinkuro Sato
  • Publication number: 20140352604
    Abstract: A method for growing a ?-Ga2O3 single crystal, which is capable of effectively suppressing twinning of the using an Edge-defined film-fed growth (EFG) method, includes: a seed crystal brought into contact with a Ga2O3 melt; and the seed crystal is pulled and a ?-Ga2O3 single crystal is grown without performing a necking process. In the method for growing a ?-Ga2O3 single crystal, the widths of the ?-Ga2O3 single crystal are 110% or less of the widths of the seed crystal in all directions.
    Type: Application
    Filed: November 12, 2012
    Publication date: December 4, 2014
    Inventors: Kimiyoshi Koshi, Haruka Matsubara, Shinya Watanabe