Patents by Inventor Noboru Ohtani

Noboru Ohtani 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: 20100289033
    Abstract: The present invention provides a single-crystal silicon carbide ingot capable of providing a good-quality substrate low in dislocation defects, and a substrate and epitaxial wafer obtained therefrom. It is a single-crystal silicon carbide ingot comprising single-crystal silicon carbide which contains donor-type impurity at a concentration of 2×1018 cm?3 to 6×1020 cm3 and acceptor-type impurity at a concentration of 1×1018 cm?3 to 5.99×1020 cm?3 and wherein the concentration of the donor-type impurity is greater than the concentration of the acceptor-type impurity and the difference is 1×1018 cm?3 to 5.99×1020 cm?3, and a substrate and epitaxial wafer obtained therefrom.
    Type: Application
    Filed: January 14, 2009
    Publication date: November 18, 2010
    Inventors: Noboru Ohtani, Masakazu Katsuno, Hiroshi Tsuge, Masashi Nakabayashi, Tatsuo Fujimoto
  • Patent number: 7799305
    Abstract: The present invention provides a semi-insulating silicon carbide single crystal characterized by having an electrical resistivity at room temperature of 1×105 ?cm or more, and a semi-insulating silicon carbide single crystal characterized by having an electrical resistivity at room temperature of 1×105 ?cm or more and vacancy pairs (bivacancies), and an semi-insulating silicon carbide single crystal characterized by having an electrical resistivity at room temperature of 1×105 ?cm or more and containing a crystal region where a position average lifetime becomes a lifetime longer than 155 ps in measurement of position lifetime at a liquid nitrogen boiling point temperature (77K) or less, and wafer obtained therefrom.
    Type: Grant
    Filed: June 15, 2005
    Date of Patent: September 21, 2010
    Assignee: Nippon Steel Corporation
    Inventors: Mitsuru Sawamura, Tatsuo Fujimoto, Noboru Ohtani, Masashi Nakabayashi
  • Patent number: 7794842
    Abstract: The present invention provides a high resistivity, high quality, large size SiC single crystal, SiC single crystal wafer, and method of production of the same, that is, a silicon carbide single crystal containing uncompensated impurities in an atomic number density of 1 ×1015/cm3 or more and containing vanadium in an amount less than said uncompensated impurity concentration, silicon carbide single crystal wafer obtained by processing and polishing the silicon carbide single crystal and having an electrical resistivity at room temperature of 5×103 ?cm or more, and a method of production of a silicon carbide single crystal.
    Type: Grant
    Filed: December 27, 2004
    Date of Patent: September 14, 2010
    Assignee: Nippon Steel Corporation
    Inventors: Masashi Nakabayashi, Tatsuo Fujimoto, Mitsuru Sawamura, Noboru Ohtani
  • Publication number: 20100147578
    Abstract: Disclosed is a light-transmitting electromagnetic-shielding laminate, which is characterized in that two or more layers including an electromagnetic-shielding layer are arranged in layers using a (meth)acrylate adhesive composition which contains a (meth)acrylate monomer, a (meth)acrylate oligomer and at least one member selected from the group consisting of acrylic amide derivatives, silane compounds and organophosphorus compounds. Also disclosed is a light-transmitting radio wave absorber which is characterized in that a resistive layer, a dielectric spacer and a reflective layer are arranged in layers using a (meth)acrylate adhesive composition which contains a (meth)acrylate monomer, a (meth)acrylate oligomer and at least one member selected from the group consisting of acrylic amide derivatives, silane compounds and organophosphorus compounds.
    Type: Application
    Filed: March 11, 2008
    Publication date: June 17, 2010
    Inventors: Takatoshi Matsumura, Noboru Ohtani, Yoshiyuki Masuda, Masahiko Ishikawa, Yoshiya Kimura, Kyoko Nishizaki, Yoshitaka Masuda
  • Publication number: 20100147212
    Abstract: Provided is a monocrystalline silicon carbide ingot containing a dopant element, wherein a maximum concentration of the dopant element is less than 5×1017 atoms/cm3 and the maximum concentration is 50 times or less than that of a minimum concentration of the dopant element. Also provided is a monocrystalline silicon carbide wafer made by cutting and polishing the monocrystalline silicon carbide ingot, wherein a electric resistivity at room temperature of the wafer is 5×103 ?cm or more. Further provided is a method for manufacturing the monocrystalline silicon carbide including growing the monocrystalline silicon carbide on a seed crystal from a sublimation material by a sublimation method. The sublimation material includes a solid material containing a dopant element, and the specific surface of the solid material containing the dopant element is 0.5 m2/g or less.
    Type: Application
    Filed: February 18, 2010
    Publication date: June 17, 2010
    Inventors: Masashi NAKABAYASHI, Tatsuo FUJIMOTO, Mitsuru SAWAMURA, Noboru OHTANI
  • Publication number: 20100089311
    Abstract: The present invention relates to a seed crystal consisting of a silicon carbide single crystal suitable for producing a substrate (wafer) for an electric power device, a high-frequency device or the like, and a method for producing an ingot using the same. A single crystal growing face of a seed crystal consisting of a silicon carbide single crystal is inclined at an angle ranging from 3 degrees or more to 60 degrees or less with respect to the (11-20) face to a direction inclined at an angle ranging from ?45 degrees or more to 45 degrees or less from a <0001> direction to the [1-100] direction. By performing crystal growth using such a seed crystal, a high quality silicon carbide single crystal ingot can be obtained. According to the present invention, it is possible to obtain material consisting of a silicon carbide single crystal of favorable quality, which has few crystal defects such as micropipe defects and stacking faults, and the diameter is suitable for practical application.
    Type: Application
    Filed: December 10, 2009
    Publication date: April 15, 2010
    Applicant: Nippon Steel Corporation
    Inventors: Noboru Ohtani, Masakazu Katsuno, Tatsuo Fujimoto
  • Publication number: 20100083897
    Abstract: The present invention relates to a seed crystal consisting of a silicon carbide single crystal suitable for producing a substrate (wafer) for an electric power device, a high-frequency device or the like, and a method for producing an ingot using the same. A single crystal growing face of a seed crystal consisting of a silicon carbide single crystal is inclined at an angle ranging from 3 degrees or more to 60 degrees or less with respect to the (11-20) face to a direction inclined at an angle ranging from ?45 degrees or more to 45 degrees or less from a <0001> direction to the [1-100] direction. By performing crystal growth using such a seed crystal, a high quality silicon carbide single crystal ingot can be obtained. According to the present invention, it is possible to obtain material consisting of a silicon carbide single crystal of favorable quality, which has few crystal defects such as micropipe defects and stacking faults, and the diameter is suitable for practical application.
    Type: Application
    Filed: December 2, 2009
    Publication date: April 8, 2010
    Applicant: Nippon Steel Corporation
    Inventors: Noboru Ohtani, Masakazu Katsuno, Tatsuo Fujimoto
  • Publication number: 20100080956
    Abstract: The invention provides a low resistivity silicon carbide single crystal wafer for fabricating semiconductor devices having excellent characteristics. The low resistivity silicon carbide single crystal wafer has a specific volume resistance of 0.001 ?cm to 0.012 ?cm and 90% or greater of the entire wafer surface area is covered by an SiC single crystal surface of a roughness (Ra) of 1.0 nm or less.
    Type: Application
    Filed: December 1, 2009
    Publication date: April 1, 2010
    Inventors: Tatsuo Fujimoto, Noboru Ohtani, Masakazu Katsuno, Masashi Nakabayashi, Hirokatsu Yashiro
  • Publication number: 20090255458
    Abstract: The present invention provides a high resistivity, high quality, large size SiC single crystal, SiC single crystal wafer, and method of production of the same, that is, a silicon carbide single crystal containing uncompensated impurities in an atomic number density of 1×1015/cm3 or more and containing vanadium in an amount less than said uncompensated impurity concentration, silicon carbide single crystal wafer obtained by processing and polishing the silicon carbide single crystal and having an electrical resistivity at room temperature of 5×103 ?cm or more, and a method of production of a silicon carbide single crystal.
    Type: Application
    Filed: May 29, 2009
    Publication date: October 15, 2009
    Applicant: Nippon Steel Corporation
    Inventors: Masashi Nakabayashi, Tatsuo Fujimoto, Mitsuru Sawamura, Noboru Ohtani
  • Publication number: 20090205565
    Abstract: The invention provides an apparatus for manufacturing good quality single-crystal silicon carbide stably without formation of cracks and the like, which apparatus comprises: at least a crucible for accommodating silicon carbide feedstock powder and seed crystal; heat insulation material installed around the crucible; and a heating device for heating the crucible, wherein the outer profile of the crucible includes at least one region of narrower diameter than a vertically adjacent region, insulation material is also installed in the space left by the diameter difference, and thickness of the insulation material at the narrower diameter region is greater than that of the insulation material at the vertically adjacent region. The apparatus for manufacturing single-crystal silicon carbide enables precise control of the temperature gradient inside the crucible, thereby enabling manufacture of good quality single-crystal silicon carbide.
    Type: Application
    Filed: April 1, 2009
    Publication date: August 20, 2009
    Inventors: Masashi Nakabayashi, Tatsuo Fujimoto, Hiroshi Tsuge, Masakazu Katsuno, Noboru Ohtani
  • Publication number: 20080302981
    Abstract: The present invention provides a light-transmitting electromagnetic wave-shielding material for use in displays or in-vehicle panels each having a polarizing plate or a retardation plate, wherein the light-transmitting electromagnetic wave-shielding material undergoes no generation of light interference fringes and is satisfactory in visibility even through sunglasses, goggles, glare-proof panels or glare-proof window materials having polarizing capability. By using unstretched light-transmitting organic polymer materials low in molecular orientation or small in molecular orientation unevenness as the base substrate of an electromagnetic wave-shielding layer, the light-transmitting electromagnetic wave-shielding material excellent in light interference fringe prevention capability can be obtained.
    Type: Application
    Filed: June 3, 2008
    Publication date: December 11, 2008
    Inventors: Takatoshi Matsumura, Masahiko Ishikawa, Yoshitaka Masuda, Noboru Ohtani, Yoshiya Kimura, Yoshiyuki Masuda, Noriyuki Kato
  • Publication number: 20080220232
    Abstract: The present invention provides a high resistivity, high quality, large size SiC single crystal, SiC single crystal wafer, and method of production of the same, that is, a silicon carbide single crystal containing uncompensated impurities in an atomic number density of 1×1015/cm3 or more and containing vanadium in an amount less than said uncompensated impurity concentration, silicon carbide single crystal wafer obtained by processing and polishing the silicon carbide single crystal and having an electrical resistivity at room temperature of 5×103 ?cm or more, and a method of production of a silicon carbide single crystal.
    Type: Application
    Filed: December 27, 2004
    Publication date: September 11, 2008
    Inventors: Masashi Nakabayashi, Tatsuo Fujimoto, Mitsuru Sawamura, Noboru Ohtani
  • Publication number: 20080038531
    Abstract: The present invention provides a semi-insulating silicon carbide single crystal characterized by having an electrical resistivity at room temperature of 1×105 ?cm or more, and a semi-insulating silicon carbide single crystal characterized by having an electrical resistivity at room temperature of 1×105 ?cm or more and vacancy pairs (bivacancies), and an semi-insulating silicon carbide single crystal characterized by having an electrical resistivity at room temperature of 1×105 ?cm or more and containing a crystal region where a position average lifetime becomes a lifetime longer than 155 ps in measurement of position lifetime at a liquid nitrogen boiling point temperature (77K) or less, and wafer obtained therefrom.
    Type: Application
    Filed: June 15, 2005
    Publication date: February 14, 2008
    Inventors: Mitsuru Sawamura, Tatsuo Fujimoto, Noboru Ohtani, Masashi Nakabayashi
  • Publication number: 20080020212
    Abstract: The present invention relates to a seed crystal consisting of a silicon carbide single crystal suitable for producing a substrate (wafer) for an electric power device, a high-frequency device or the like, and a method for producing an ingot using the same. A single crystal growing face of a seed crystal consisting of a silicon carbide single crystal is inclined at an angle ranging from 3 degrees or more to 60 degrees or less with respect to the (11-20) face to a direction inclined at an angle ranging from ?45 degrees or more to 45 degrees or less from a <0001> direction to the [1-100] direction. By performing crystal growth using such a seed crystal, a high quality silicon carbide single crystal ingot can be obtained. According to the present invention, it is possible to obtain material consisting of a silicon carbide single crystal of favorable quality, which has few crystal defects such as micropipe defects and stacking faults, and the diameter is suitable for practical application.
    Type: Application
    Filed: September 13, 2007
    Publication date: January 24, 2008
    Applicant: Nippon Steel Corporation
    Inventors: Noboru Ohtani, Masakazu Katsuno, Tatsuo Fujimoto
  • Publication number: 20070262322
    Abstract: Provided is a monocrystalline silicon carbide ingot containing a dopant element, wherein a maximum concentration of the dopant element is less than 5×1017 atoms/cm3 and the maximum concentration is 50 times or less than that of a minimum concentration of the dopant element. Also provided is a monocrystalline silicon carbide wafer made by cutting and polishing the monocrystalline silicon carbide ingot, wherein a electric resistivity at room temperature of the wafer is 5×103 ?cm or more. Further provided is a method for manufacturing the monocrystalline silicon carbide including growing the monocrystalline silicon carbide on a seed crystal from a sublimation material by a sublimation method. The sublimation material includes a solid material containing a dopant element, and the specific surface of the solid material containing the dopant element is 0.5 m2/g or less.
    Type: Application
    Filed: October 5, 2005
    Publication date: November 15, 2007
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Masashi Nakabayashi, Tatsuo Fujimoto, Mitsuru Sawamura, Noboru Ohtani
  • Publication number: 20050160965
    Abstract: The present invention relates to a seed crystal consisting of a silicon carbide single crystal suitable for producing a substrate (wafer) for an electric power device, a high-frequency device or the like, and a method for producing an ingot using the same. A single crystal growing face of a seed crystal consisting of a silicon carbide single crystal is inclined at an angle ranging from 3 degrees or more to 60 degrees or less with respect to the (11-20) face to a direction inclined at an angle ranging from ?45 degrees or more to 45 degrees or less from a <0001> direction to the [1-100] direction. By performing crystal growth using such a seed crystal, a high quality silicon carbide single crystal ingot can be obtained. According to the present invention, it is possible to obtain material consisting of a silicon carbide single crystal of favorable quality, which has few crystal defects such as micropipe defects and stacking faults, and the diameter is suitable for practical application.
    Type: Application
    Filed: March 31, 2003
    Publication date: July 28, 2005
    Applicant: Nippon Steel Corporation
    Inventors: Noboru Ohtani, Masakazu Katsuno, Tatsuo Fujimoto
  • Patent number: 6305910
    Abstract: A multi-stage pump device includes a plurality of pump devices, each of the pump devices having a pump portion feeding working fluid under pressure, and a connecting portion provided between at least two of the pump devices, through which working fluid pumped by the respective pump devices passes. The connecting portion is expandable in a direction of the length thereof and is provided with a sealing structure to prevent a leakage of the working fluid. The connecting portion may be two telescopically arranged pipes or a bellows.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: October 23, 2001
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Atsuyuki Miura, Yoshihiro Naito, Noboru Ohtani, Koichi Nakayama
  • Patent number: 5958132
    Abstract: A method for the growth of a SiC single crystal comprisingintroducing a seed crystal of SiC single crystal having an exposed face deviating from the {0001} plane by an angle .alpha..sub.1 of about 60.degree. to about 120.degree., typically about 90.degree. and SiC powder as a raw material into a graphite crucible,elevating the temperature of the SiC powder in an atmosphere of inert gas to a level sufficient for sublimation, meanwhileelevating the temperature of the exposed face of the seed crystal to a level slightly lower than the temperature of the SiC powder, andkeeping the SiC powder and the seed crystal at the specific temperatures for a period enough for a SiC single crystal of the same polytype as the seed crystal to grow to a desired height on the exposed face of the seed crystal.
    Type: Grant
    Filed: May 14, 1997
    Date of Patent: September 28, 1999
    Assignee: Nippon Steel Corporation
    Inventors: Jun Takahashi, Masatoshi Kanaya, Yuichiro Fujiwara, Noboru Ohtani
  • Patent number: 5907470
    Abstract: The present invention provides a dielectric thin film capacitor element in which leak current may be suppressed from increasing over time while energizing at high temperature and which has excellent insulating quality and reliability and a manufacturing method thereof. The dielectric thin film capacitor element is constructed by forming a lower electrode, a dielectric thin film and an upper electrode one after another on a substrate, wherein the dielectric thin film capacitor element is characterized in that the dielectric thin film is made of an oxide material composed of at least titanium and strontium and containing erbium.
    Type: Grant
    Filed: June 6, 1997
    Date of Patent: May 25, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Ryusuke Kita, Yoshiyuki Masuda, Yoshiyuki Matsu, Noboru Ohtani, Seiki Yano
  • Patent number: 5856242
    Abstract: A method for preparing an oxide dielectric thin film, for use in a dielectric thin film device, is described. Briefly, a film forming chamber is heated, and a thin film of dielectric, about 200 nm thick, is formed by sputtering or another deposition method. After the film is formed, evacuation of the film forming chamber is suspended, and oxygen gas is introduced into the chamber. The film is oxidized after its formation by maintaining the film in the oxygen atmosphere for a period of time, which can include cooling steps. The resulting dielectric thin film has excellent dielectric properties, such as a high dielectric constant and great dielectric strength.
    Type: Grant
    Filed: June 27, 1996
    Date of Patent: January 5, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hisako Arai, Ryusuke Kita, Yoshiyuki Masuda, Noboru Ohtani, Yoshiyuki Matsu, Masayoshi Koba