Patents by Inventor Shigekazu Tomai

Shigekazu Tomai 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: 10636914
    Abstract: A crystalline oxide semiconductor thin film that is composed mainly of indium oxide and comprises surface crystal grains having a single crystal orientation.
    Type: Grant
    Filed: July 29, 2016
    Date of Patent: April 28, 2020
    Assignee: IDEMITSU KOSAN CO., LTD.
    Inventors: Kazuyoshi Inoue, Futoshi Utsuno, Yuki Tsuruma, Shigekazu Tomai, Kazuaki Ebata
  • Patent number: 10374045
    Abstract: A semiconductor device 1 which comprises a pair of an ohmic electrode 20 and a Schottky electrode 10 separated from each other, and a semiconductor layer 30 in contact with the ohmic electrode 20 and the Schottky electrode 10, and which satisfies the following formula (I): n < ? ? ? V e qL 2 ( I ) in which n is a carrier concentration (cm?3) of the semiconductor layer, ? is a dielectric constant (F/cm) of the semiconductor layer, Ve is a forward effective voltage (V) between the ohmic electrode and the Schottky electrode, q is an elementary charge (C), and L is a distance (cm) between the ohmic electrode and the Schottky electrode.
    Type: Grant
    Filed: December 21, 2016
    Date of Patent: August 6, 2019
    Assignee: IDEMITSU KOSAN CO., LTD.
    Inventors: Yuki Tsuruma, Takashi Sekiya, Shigekazu Tomai, Emi Kawashima, Yoshihiro Ueoka
  • Publication number: 20190218145
    Abstract: An oxide sintered body includes a bixbyite phase represented by In2O3, and a garnet phase represented by Y3In2Ga3O12.
    Type: Application
    Filed: June 16, 2017
    Publication date: July 18, 2019
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventors: Kazuyoshi INOUE, Shigekazu TOMAI, Masatoshi SHIBATA, Motohiro TAKESHIMA
  • Patent number: 10340356
    Abstract: A laminated body comprising a substrate, an ohmic electrode layer, a metal oxide semiconductor layer, a Schottky electrode layer and a buffer electrode layer in this order, wherein a reduction suppressing layer is provided between the Schottky electrode layer and the buffer electrode layer.
    Type: Grant
    Filed: December 26, 2016
    Date of Patent: July 2, 2019
    Assignee: IDEMITSU KOSAN CO., LTD.
    Inventors: Emi Kawashima, Takashi Sekiya, Yuki Tsuruma, Yoshihiro Ueoka, Shigekazu Tomai, Motohiro Takeshima
  • Publication number: 20190177176
    Abstract: A garnet compound represented by a general formula (I): Ln3In2Ga3-XAlXO12 (I) (in the formula, Ln represents one or more metal elements selected from La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; and X satisfies an expression 0?X<3).
    Type: Application
    Filed: August 25, 2017
    Publication date: June 13, 2019
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventors: Kazuyoshi INOUE, Shigekazu TOMAI, Masatoshi SHIBATA
  • Publication number: 20190013389
    Abstract: A laminated body comprising a substrate, an ohmic electrode layer, a metal oxide semiconductor layer, a Schottky electrode layer and a buffer electrode layer in this order, wherein a reduction suppressing layer is provided between the Schottky electrode layer and the buffer electrode layer.
    Type: Application
    Filed: December 26, 2016
    Publication date: January 10, 2019
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventors: Emi KAWASHIMA, Takashi SEKIYA, Yuki TSURUMA, Yoshihiro UEOKA, Shigekazu TOMAI, Motohiro TAKESHIMA
  • Publication number: 20190006473
    Abstract: A semiconductor device 1 which comprises a pair of an ohmic electrode 20 and a Schottky electrode 10 separated from each other, and a semiconductor layer 30 in contact with the ohmic electrode 20 and the Schottky electrode 10, and which satisfies the following formula (I): n < ? ? ? V e qL 2 ( I ) in which n is a carrier concentration (cm?3) of the semiconductor layer, ? is a dielectric constant (F/cm) of the semiconductor layer, Ve is a forward effective voltage (V) between the ohmic electrode and the Schottky electrode, q is an elementary charge (C), and L is a distance (cm) between the ohmic electrode and the Schottky electrode.
    Type: Application
    Filed: December 21, 2016
    Publication date: January 3, 2019
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventors: Yuki TSURUMA, Takashi SEKIYA, Shigekazu TOMAI, Emi KAWASHIMA, Yoshihiro UEOKA
  • Publication number: 20180219098
    Abstract: A crystalline oxide semiconductor thin film that is composed mainly of indium oxide and comprises surface crystal grains having a single crystal orientation.
    Type: Application
    Filed: July 29, 2016
    Publication date: August 2, 2018
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventors: Kazuyoshi INOUE, Futoshi UTSUNO, Yuki TSURUMA, Shigekazu TOMAI, Kazuaki EBATA
  • Patent number: 9767998
    Abstract: A sputtering target including a sintered body: the sintered body including: indium oxide doped with Ga or indium oxide doped with Al, and a positive tetravalent metal in an amount of exceeding 100 at. ppm and 1100 at. ppm or less relative to the total of Ga and indium, or Al and indium, the crystal structure of the sintered body substantially including a bixbyite structure of indium oxide.
    Type: Grant
    Filed: September 6, 2012
    Date of Patent: September 19, 2017
    Assignee: IDEMITSU KOSAN CO., LTD.
    Inventors: Kazuaki Ebata, Shigekazu Tomai, Shigeo Matsuzaki, Yuki Tsuruma
  • Publication number: 20170263786
    Abstract: A schottky barrier diode element having a silicon (Si) substrate, an oxide semiconductor layer and a schottky electrode layer, wherein the oxide semiconductor layer includes a polycrystalline and/or amorphous oxide semiconductor having a band gap of 3.0 eV or more and 5.6 eV or less.
    Type: Application
    Filed: May 25, 2017
    Publication date: September 14, 2017
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventors: Shigekazu TOMAI, Masatoshi SHIBATA, Emi KAWASHIMA, Koki YANO, Hiromi HAYASAKA
  • Patent number: 9691910
    Abstract: A schottky barrier diode element having a silicon (Si) substrate, an oxide semiconductor layer and a schottky electrode layer, wherein the oxide semiconductor layer includes a polycrystalline and/or amorphous oxide semiconductor having a band gap of 3.0 eV or more and 5.6 eV or less.
    Type: Grant
    Filed: August 8, 2014
    Date of Patent: June 27, 2017
    Assignee: IDEMITSU KOSAN CO., LTD.
    Inventors: Shigekazu Tomai, Masatoshi Shibata, Emi Kawashima, Koki Yano, Hiromi Hayasaka
  • Publication number: 20170141240
    Abstract: A Schottky barrier diode element includes an n-type or p-type silicon (Si) substrate, an oxide semiconductor layer, and a Schottky electrode layer, the oxide semiconductor layer including either or both of a polycrystalline oxide that includes gallium (Ga) as the main component and an amorphous oxide that includes gallium (Ga) as the main component.
    Type: Application
    Filed: December 28, 2016
    Publication date: May 18, 2017
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventors: Shigekazu TOMAI, Masatoshi SHIBATA, Emi KAWASHIMA, Koki YANO, Hiromi HAYASAKA
  • Patent number: 9570631
    Abstract: A Schottky barrier diode element includes an n-type or p-type silicon (Si) substrate, an oxide semiconductor layer, and a Schottky electrode layer, the oxide semiconductor layer including either or both of a polycrystalline oxide that includes gallium (Ga) as the main component and an amorphous oxide that includes gallium (Ga) as the main component.
    Type: Grant
    Filed: August 8, 2014
    Date of Patent: February 14, 2017
    Assignee: IDEMITSU KOSAN CO., LTD.
    Inventors: Shigekazu Tomai, Masatoshi Shibata, Emi Kawashima, Koki Yano, Hiromi Hayasaka
  • Publication number: 20160343554
    Abstract: An oxide sintered body comprising a bixbyite phase composed of In2O3 and an A3B5O12 phase (wherein A is one or more elements selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and B is one or more elements selected from the group consisting of Al and Ga).
    Type: Application
    Filed: December 18, 2014
    Publication date: November 24, 2016
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventors: Shigekazu TOMAI, Kazuyoshi INOUE, Kazuaki EBATA, Masatoshi SHIBATA, Futoshi UTSUNO, Yuki TSURUMA, Yu ISHIHARA
  • Publication number: 20160211386
    Abstract: A Schottky barrier diode element includes an n-type or p-type silicon (Si) substrate, an oxide semiconductor layer, and a Schottky electrode layer, the oxide semiconductor layer including either or both of a polycrystalline oxide that includes gallium (Ga) as the main component and an amorphous oxide that includes gallium (Ga) as the main component.
    Type: Application
    Filed: August 8, 2014
    Publication date: July 21, 2016
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventors: Shigekazu TOMAI, Masatoshi SHIBATA, Emi KAWASHIMA, Koki YANO, Hiromi HAYASAKA
  • Publication number: 20160197202
    Abstract: A schottky barrier diode element having a silicon (Si) substrate, an oxide semiconductor layer and a schottky electrode layer, wherein the oxide semiconductor layer includes a polycrystalline and/or amorphous oxide semiconductor having a band gap of 3.0 eV or more and 5.6 eV or less.
    Type: Application
    Filed: August 8, 2014
    Publication date: July 7, 2016
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventors: Shigekazu TOMAI, Masatoshi SHIBATA, Emi KAWASHIMA, Koki YANO, Hiromi HAYASAKA
  • Patent number: 9269573
    Abstract: To provide a thin film transistor having an indium oxide-based semiconductor film which allows only a thin metal film on the semiconductor film to be selectively etched. A thin film transistor having a crystalline indium oxide semiconductor film which is composed mainly of indium oxide and contains a positive trivalent metal oxide.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: February 23, 2016
    Assignee: IDEMITSU KOSAN CO., LTD.
    Inventors: Kazuyoshi Inoue, Koki Yano, Shigekazu Tomai, Futoshi Utsuno, Masashi Kasami, Kenji Goto, Hirokazu Kawashima
  • Patent number: 9243318
    Abstract: A sintered body which includes at least indium oxide and gallium oxide and comprises voids each having a volume of 14000 ?m3 or more in an amount of 0.03 vol % or less.
    Type: Grant
    Filed: March 26, 2012
    Date of Patent: January 26, 2016
    Assignee: IDEMITSU KOSAN CO., LTD.
    Inventors: Shigekazu Tomai, Shigeo Matsuzaki, Koki Yano, Makoto Ando, Kazuaki Ebata, Masayuki Itose
  • Patent number: 9178076
    Abstract: A thin film transistor (1) includes a source electrode (50), a drain electrode (60), a gate electrode (20), a gate insulating film (30), and a channel layer (40) that is formed of an oxide semiconductor, the channel layer (40) having an average carrier concentration of 1×1016/cm3 to 5×1019/cm3, and including a high carrier concentration region (42) that is situated on the side of the gate insulating film (30) and has a carrier concentration higher than the average carrier concentration, and the channel layer (40) having a substantially homogenous composition.
    Type: Grant
    Filed: August 8, 2012
    Date of Patent: November 3, 2015
    Assignee: IDEMITSU KOSAN CO., LTD.
    Inventors: Yuki Tsuruma, Kazuaki Ebata, Shigekazu Tomai, Shigeo Matsuzaki
  • Patent number: 9153438
    Abstract: An oxide sintered body including an oxide of indium and aluminum and having an atomic ratio Al/(Al+In) of 0.01 to 0.08.
    Type: Grant
    Filed: May 24, 2011
    Date of Patent: October 6, 2015
    Assignee: IDEMITSU KOSAN CO., LTD.
    Inventors: Kazuaki Ebata, Shigekazu Tomai, Koki Yano, Kazuyoshi Inoue