Patents by Inventor Shinsuke Fujiwara

Shinsuke Fujiwara 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: 11242618
    Abstract: A silicon carbide substrate capable of stably forming a device of excellent performance, and a method of manufacturing the same are provided. A silicon carbide substrate is made of a single crystal of silicon carbide, and has a width of not less than 100 mm, a micropipe density of not more than 7 cm?2, a threading screw dislocation density of not more than 1×104 cm?2, a threading edge dislocation density of not more than 1×104 cm?2, a basal plane dislocation density of not more than 1×104 cm?2, a stacking fault density of not more than 0.1 cm?1, a conductive impurity concentration of not less than 1×1018 cm?3, a residual impurity concentration of not more than 1×1016 cm?3, and a secondary phase inclusion density of not more than 1 cm?3.
    Type: Grant
    Filed: December 22, 2015
    Date of Patent: February 8, 2022
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Shin Harada, Shinsuke Fujiwara, Taro Nishiguchi
  • 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
  • Patent number: 9583571
    Abstract: A semiconductor substrate has a main surface and formed of single crystal silicon carbide. The main surface includes a central area, which is an area other than the area within 5 mm from the outer circumference. When the central area is divided into square areas of 1 mm×1 mm, in any square area, density of dislocations of which Burgers vector is parallel to <0001> direction is at most 1×105 cm?2. Thus, a silicon carbide semiconductor substrate enabling improved yield of semiconductor devices can be provided.
    Type: Grant
    Filed: October 2, 2015
    Date of Patent: February 28, 2017
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Taro Nishiguchi, Shin Harada, Shinsuke Fujiwara
  • Patent number: 9450054
    Abstract: A semiconductor substrate has a main surface and formed of single crystal silicon carbide. The main surface includes a central area, which is an area other than the area within 5 mm from the outer circumference. When the central area is divided into square areas of 1 mm×1 mm, in any square area, density of dislocations of which Burgers vector is parallel to <0001> direction is at most 1×105 cm?2. Thus, a silicon carbide semiconductor substrate enabling improved yield of semiconductor devices can be provided.
    Type: Grant
    Filed: November 7, 2014
    Date of Patent: September 20, 2016
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Taro Nishiguchi, Shin Harada, Shinsuke Fujiwara
  • Patent number: 9368568
    Abstract: Group III nitride crystal produced by cutting, from III nitride bulk crystal, a plurality of Group III nitride crystal substrates with major-surface plane orientation misoriented five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20-21}, {20-2-1}, {22-41}, and {22-4-1}, transversely arranging the substrates adjacent to each other such that their major surfaces are parallel to each other and such that their [0001] directions coincide with each other, and growing a Group III nitride crystal on the major surfaces. The Group III nitride crystal substrates are further characterized by satisfying at least either an oxygen-atom concentration of 1×1016 cm?3 to 4×1019 cm?3 or a silicon-atom concentration of 6×1014 cm?3 to 5×1018 cm?3, and by having a carrier concentration of 1×1016 cm?3 to 6×1019 cm?3.
    Type: Grant
    Filed: August 27, 2014
    Date of Patent: June 14, 2016
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Koji Uematsu, Hideki Osada, Seiji Nakahata, Shinsuke Fujiwara
  • Publication number: 20160108553
    Abstract: A silicon carbide substrate capable of stably forming a device of excellent performance, and a method of manufacturing the same are provided. A silicon carbide substrate is made of a single crystal of silicon carbide, and has a width of not less than 100 mm, a micropipe density of not more than 7 cm?2, a threading screw dislocation density of not more than 1×104 cm?2, a threading edge dislocation density of not more than 1×104 cm?2, a basal plane dislocation density of not more than 1×104 cm 2, a stacking fault density of not more than 0.1 cm?1, a conductive impurity concentration of not less than 1×1018 cm 3, a residual impurity concentration of not more than 1×1016 cm?3, and a secondary phase inclusion density of not more than 1 cm?3.
    Type: Application
    Filed: December 22, 2015
    Publication date: April 21, 2016
    Inventors: Shin HARADA, Shinsuke FUJIWARA, Taro NISHIGUCHI
  • Patent number: 9279194
    Abstract: Affords a method of growing, across the entirety of a major surface of a first III-nitride crystal, a second III-nitride crystal by HVPE, in an ambient temperature higher than 1100° C. The present III-nitride crystal growth method comprises: a step of preparing a first III-nitride crystal (10) having an alkali-metal atom concentration of less than 1.0×1018 cm?3; and a step of growing a second III-nitride crystal (20) onto a major surface (10m) of the first III-nitride crystal (10) by HVPE, in an ambient temperature higher than 1100° C.
    Type: Grant
    Filed: December 3, 2009
    Date of Patent: March 8, 2016
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Hiroaki Yoshida, Shinsuke Fujiwara, Koji Uematsu, Masanori Morishita
  • Patent number: 9255344
    Abstract: A silicon carbide substrate capable of stably forming a device of excellent performance, and a method of manufacturing the same are provided. A silicon carbide substrate is made of a single crystal of silicon carbide, and has a width of not less than 100 mm, a micropipe density of not more than 7 cm?2, a threading screw dislocation density of not more than 1×104 cm?2, a threading edge dislocation density of not more than 1×104 cm?2, a basal plane dislocation density of not more than 1×104 cm?2, a stacking fault density of not more than 0.1 cm?1, a conductive impurity concentration of not less than 1×1018 cm?3, a residual impurity concentration of not more than 1×1016 cm?3, and a secondary phase inclusion density of not more than 1 cm?3.
    Type: Grant
    Filed: September 6, 2012
    Date of Patent: February 9, 2016
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Shin Harada, Shinsuke Fujiwara, Taro Nishiguchi
  • Publication number: 20160027879
    Abstract: A semiconductor substrate has a main surface and formed of single crystal silicon carbide. The main surface includes a central area, which is an area other than the area within 5 mm from the outer circumference. When the central area is divided into square areas of 1 mm×1 mm, in any square area, density of dislocations of which Burgers vector is parallel to <0001> direction is at most 1×105 cm?2. Thus, a silicon carbide semiconductor substrate enabling improved yield of semiconductor devices can be provided.
    Type: Application
    Filed: October 2, 2015
    Publication date: January 28, 2016
    Inventors: Taro NISHIGUCHI, Shin HARADA, Shinsuke FUJIWARA
  • Patent number: 9184239
    Abstract: A semiconductor substrate has a main surface and formed of single crystal silicon carbide. The main surface includes a central area, which is an area other than the area within 5 mm from the outer circumference. When the central area is divided into square areas of 1 mm×1 mm, in any square area, density of dislocations of which Burgers vector is parallel to <0001> direction is at most 1×105 cm?2. Thus, a silicon carbide semiconductor substrate enabling improved yield of semiconductor devices can be provided.
    Type: Grant
    Filed: November 7, 2014
    Date of Patent: November 10, 2015
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Taro Nishiguchi, Shin Harada, Shinsuke Fujiwara
  • Patent number: 9153742
    Abstract: A GaN-crystal free-standing substrate obtained from a GaN crystal grown by HVPE with a (0001) plane serving as a crystal growth plane and at least one plane of a {10-11} plane and a {11-22} plane serving as a crystal growth plane that constitutes a facet crystal region, except for the side surface of the crystal, wherein the (0001)-plane-growth crystal region has a carbon concentration of 5×1016 atoms/cm3 or less, a silicon concentration of 5×1017 atoms/cm3 or more and 2×1018 atoms/cm3 or less, and an oxygen concentration of 1×1017 atoms/cm3 or less; and the facet crystal region has a carbon concentration of 3×1016 atoms/cm3 or less, a silicon concentration of 5×1017 atoms/cm3 or less, and an oxygen concentration of 5×1017 atoms/cm3 or more and 5×1018 atoms/cm3 or less.
    Type: Grant
    Filed: July 2, 2013
    Date of Patent: October 6, 2015
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shinsuke Fujiwara, Koji Uematsu, Hitoshi Kasai, Takuji Okahisa
  • 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
  • Publication number: 20150118830
    Abstract: The present method of manufacturing a GaN-based film includes the steps of preparing a composite substrate (10) including a support substrate (11) dissoluble in hydrofluoric acid and a single crystal film (13) arranged on a side of a main surface (11m) of the support substrate (11), a coefficient of thermal expansion in the main surface (11m) of the support substrate (11) being more than 0.8 time and less than 1.2 times as high as a coefficient of thermal expansion of GaN crystal, forming a GaN-based film (20) on a main surface (13m) of the single crystal film (13) arranged on the side of the main surface (11m) of the support substrate (11), and removing the support substrate (11) by dissolving the support substrate (11) in hydrofluoric acid. Thus, the method of manufacturing a GaN-based film capable of efficiently obtaining a GaN-based film having a large main surface area, less warpage, and good crystallinity, as well as a composite substrate used therefor are provided.
    Type: Application
    Filed: January 5, 2015
    Publication date: April 30, 2015
    Inventors: Issei SATOH, Yuki SEKI, Koji UEMATSU, Yoshiyuki YAMAMOTO, Hideki MATSUBARA, Shinsuke FUJIWARA, Masashi YOSHIMURA
  • Patent number: 9005362
    Abstract: The present invention is to provide a method for growing a group III nitride crystal that has a large size and has a small number of pits formed in the main surface of the crystal by using a plurality of tile substrates. A method for growing a group III nitride crystal includes a step of preparing a plurality of tile substrates 10 including main surfaces 10m having a shape of a triangle or a convex quadrangle that allows two-dimensional close packing of the plurality of tile substrates; a step of arranging the plurality of tile substrates 10 so as to be two-dimensionally closely packed such that, at any point across which vertexes of the plurality of tile substrates 10 oppose one another, 3 or less of the vertexes oppose one another; and a step of growing a group III nitride crystal 20 on the main surfaces 10m of the plurality of tile substrates arranged.
    Type: Grant
    Filed: May 25, 2011
    Date of Patent: April 14, 2015
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yuki Hiromura, Koji Uematsu, Hiroaki Yoshida, Shinsuke Fujiwara
  • Publication number: 20150060886
    Abstract: A semiconductor substrate has a main surface and formed of single crystal silicon carbide. The main surface includes a central area, which is an area other than the area within 5 mm from the outer circumference. When the central area is divided into square areas of 1 mm×1 mm, in any square area, density of dislocations of which Burgers vector is parallel to <0001> direction is at most 1×105 cm?2. Thus, a silicon carbide semiconductor substrate enabling improved yield of semiconductor devices can be provided.
    Type: Application
    Filed: November 7, 2014
    Publication date: March 5, 2015
    Inventors: Taro NISHIGUCHI, Shin HARADA, Shinsuke FUJIWARA
  • Patent number: 8963166
    Abstract: Toward making available III nitride crystal substrates advantageously employed in light-emitting devices, and light-emitting devices incorporating the substrates, a III nitride crystal substrate has a major face whose surface area is not less than 10 cm2 and is characterized by: edge dislocations in the crystal being concentrated along propagation lines forming an angle of some 0° to 5° with a given {0001} plane of the crystal; screw dislocations in the crystal being concentrated along propagation lines forming an angle of some 45° to 60° with the given {0001} plane; and in a major-face principal region excluding the peripheral margin of the major face from its outer periphery to a 5 mm separation from its outer periphery, the total dislocation density being between 1×104 cm?2 to 3×106 cm?2 inclusive, and the ratio of screw-dislocation density to the total dislocation density being 0.5 or greater.
    Type: Grant
    Filed: August 27, 2013
    Date of Patent: February 24, 2015
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Shinsuke Fujiwara, Hiroaki Yoshida
  • Patent number: 8962365
    Abstract: The present method of manufacturing a GaN-based film includes the steps of preparing a composite substrate including a support substrate dissoluble in hydrofluoric acid and a single crystal film arranged on a side of a main surface of the support substrate, a coefficient of thermal expansion in the main surface of the support substrate being more than 0.8 time and less than 1.2 times as high as a coefficient of thermal expansion of GaN crystal, forming a GaN-based film on a main surface of the single crystal film arranged on the side of the main surface of the support substrate, and removing the support substrate by dissolving the support substrate in hydrofluoric acid. Thus, the method of manufacturing a GaN-based film capable of efficiently obtaining a GaN-based film having a large main surface area, less warpage, and good crystallinity, as well as a composite substrate used therefor are provided.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: February 24, 2015
    Assignee: Sumitomo Electric Industies, Ltd.
    Inventors: Issei Satoh, Yuki Seki, Koji Uematsu, Yoshiyuki Yamamoto, Hideki Matsubara, Shinsuke Fujiwara, Masashi Yoshimura
  • Patent number: 8937339
    Abstract: Si(1-v-w-x)CwAlxNv crystals in a mixed crystal state are formed. A method for manufacturing an easily processable Si(1-v-w-x)CwAlxNv substrate, a method for manufacturing an epitaxial wafer, a Si(1-v-w-x)CwAlxNv substrate, and an epitaxial wafer are provided. A method for manufacturing a Si(1-v-w-x)CwAlxNv substrate 10a includes the following steps. First, a Si substrate 11 is prepared. A Si(1-v-w-x)CwAlxNv layer 12 (0<v<1, 0?w<1, 0<x<1, and 0<v+w+x<1) is then grown on the Si substrate 11 by a pulsed laser deposition method.
    Type: Grant
    Filed: December 14, 2012
    Date of Patent: January 20, 2015
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Issei Satoh, Michimasa Miyanaga, Shinsuke Fujiwara, Hideaki Nakahata
  • Publication number: 20140369920
    Abstract: Group III nitride crystal produced by cutting, from III nitride bulk crystal, a plurality of Group III nitride crystal substrates with major-surface plane orientation misoriented five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20-21}, {20-2-1}, {22-41}, and {22-4-1}, transversely arranging the substrates adjacent to each other such that their major surfaces are parallel to each other and such that their [0001] directions coincide with each other, and growing a Group III nitride crystal on the major surfaces. The Group III nitride crystal substrates are further characterized by satisfying at least either an oxygen-atom concentration of 1×1016 cm?3 to 4×1019 cm?3 or a silicon-atom concentration of 6×1014 cm?3 to 5×1018 cm?3, and by having a carrier concentration of 1×1016 cm?3 to 6×1019 cm?3.
    Type: Application
    Filed: August 27, 2014
    Publication date: December 18, 2014
    Inventors: Koji Uematsu, Hideki Osada, Seiji Nakahata, Shinsuke Fujiwara