Patents by Inventor Hidefumi Hiura

Hidefumi Hiura 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: 20040121567
    Abstract: A doping method includes the step of attaching molecules or clusters to the surface of a semiconductor substrate to enable charge transfer from the molecules or clusters to the substrate surface, thereby inducing carriers underneath the substrate surface. A semiconductor device is fabricated through attachment of molecules or clusters to the surface of a semiconductor substrate. The attachment enables charge transfer from the molecules or clusters to the substrate surface to induce carriers underneath the substrate surface.
    Type: Application
    Filed: September 5, 2003
    Publication date: June 24, 2004
    Applicants: Nat'l Inst. of Advan. Industrial Science and Tech., NEC Corporation
    Inventors: Toshihiko Kanayama, Takehide Miyazaki, Hidefumi Hiura
  • Patent number: 6680411
    Abstract: A carborane supercluster consisting of carborane (C2B10H12) as its constituent unit expressed as a molecular formula C2mB10mH12m-x, where x is a positive integer (i.e., x=1, 2, 3, . . . ) and m is an integer greater than unity (i.e., m=2, 3, . . . ). The parameter x represents the count of removed or detached hydrogen atoms. The parameter a represents the count of the clusters linked together. To produce the supercluster, carborane (C2B10H12) is ionized in a reaction chamber to generate carborane ions and then, the carborane ions thus generated are successively reacted with the remaining neutral (i.e., non-ionized) carborane (C2B10H12), thereby generating the carborane supercluster. Preferably, the cluster of the carborane consists of at least two of o-carborane, m-carborane, and p-carborane.
    Type: Grant
    Filed: May 23, 2002
    Date of Patent: January 20, 2004
    Assignees: Agency of Industrial Science and Technology, NEC Corporation
    Inventors: Toshihiko Kanayama, Hidefumi Hiura
  • Patent number: 6540972
    Abstract: A graphite having geometrically shaped holes limited to the top atomic layer such as circles, polygons and combinations thereof, and a method of preparing a graphite having geometrically shaped holes such as circles, polygons and combinations thereof where the geometrically shaped holes are limited to the top atomic layer.
    Type: Grant
    Filed: November 3, 1999
    Date of Patent: April 1, 2003
    Assignee: NEC Corporation
    Inventor: Hidefumi Hiura
  • Publication number: 20030023118
    Abstract: A carborane supercluster consisting of carborane (C2B10H12) as its constituent unit expressed as a molecular formula C2mB10mH12m-x, where x is a positive integer (i.e., x=1, 2, 3, . . . ) and m is an integer greater than unity (i.e., m=2, 3, . . . ). The parameter x represents the count of removed or detached hydrogen atoms. The parameter a represents the count of the clusters linked together. To produce the supercluster, carborane (C2B10H12) is ionized in a reaction chamber to generate carborane ions and then, the carborane ions thus generated are successively reacted with the remaining neutral (i.e., non-ionized) carborane (C2B10H12), thereby generating the carborane supercluster. Preferably, the cluster of the carborane consists of at least two of o-carborane, m-carborane, and p-carborane.
    Type: Application
    Filed: May 23, 2002
    Publication date: January 30, 2003
    Inventors: Toshihiko Kanayama, Hidefumi Hiura
  • Patent number: 6083624
    Abstract: A graphite having geometrically shaped holes limited to the top atomic layer such as circles, polygons and combinations thereof, and a method of preparing a graphite having geometrically shaped holes such as circles, polygons and combinations thereof where the geometrically shaped holes are limited to the top atomic layer.
    Type: Grant
    Filed: November 12, 1997
    Date of Patent: July 4, 2000
    Assignee: NEC Corporation
    Inventor: Hidefumi Hiura
  • Patent number: 5925465
    Abstract: A novel carbon material is obtained by bending at least one carbon atom layer of graphite in at least one selected region along either, or both, of lines I and II in FIG. 1. The bending can be accomplished by scanningly picking the carbon atom layer(s) with a probe of an atomic force microscope or another scanning microscope. The obtained carbon material has at least one round bend having a width of 0.1-10 nm and at least one flap region having a triangular, rectangular or still differently polygonal shape in plan view. When the carbon atom layer(s) is bent with very small radii of curvature, a finely striped ridge-and-groove structure appears in the round bend. The physical properties of the obtained carbon material are uniquely determined by the direction(s) of bending, width of each bend, shape and size of each flap region and the stripe pitch of the ridge-and-groove structure.
    Type: Grant
    Filed: January 17, 1997
    Date of Patent: July 20, 1999
    Assignee: NEC Corporation
    Inventors: Thomas Ebbesen, Hidefumi Hiura, Katsumi Tanigaki
  • Patent number: 5698175
    Abstract: Disclosed is a process for purifying carbon nanotubes which has steps of 1) mixing carbon nanotubes which accompany carbon impurities with a reagent selected from a group consisting of oxidation agents, nitration agents and sulfonation agents in liquid phase, 2) reacting the carbon nanotubes with the reagent at a predetermined temperature in the liquid phase, wherein the carbon impurities except carbon nanotubes are selectively reacted to dissolve in the liquid phase, and 3) separating carbon nanotubes from which the impurities were released from the liquid phase then washing and drying it. A process for uncapping carbon nanotubes and a process for chemically modifying carbon nanotubes are also disclosed.
    Type: Grant
    Filed: July 3, 1995
    Date of Patent: December 16, 1997
    Assignee: NEC Corporation
    Inventors: Hidefumi Hiura, Thomas Ebbesen
  • Patent number: 5641466
    Abstract: A mixture of carbon nanotubes and impurity carbon materials, which include carbon nanoparticles and may possibly include amorphous carbon, is purified into carbon nanotubes of high purity by utilizing a significant difference in oxidizability between the nanotubes and the nanoparticles. The mixture is pulverized and heated in the presence of an oxidizing agent at a temperature in the range from 600.degree. to 1000.degree. C. until the impurity carbon materials are oxidized and dissipated into gas phase. The nanotubes remain almost unoxidized except for loss of some lengths from the tube tips. It is suitable to perform the heating in air or oxygen.
    Type: Grant
    Filed: June 2, 1994
    Date of Patent: June 24, 1997
    Assignee: NEC Corporation
    Inventors: Thomas Ebbesen, Pulickel M. Ajayan, Hidefumi Hiura
  • Patent number: 5626812
    Abstract: A novel carbon material is obtained by bending at least one carbon atom layer of graphite in at least one selected region along either, or both, of lines I and II in FIG. 1. The bending can be accomplished by scanningly picking the carbon atom layer(s) with a probe of an atomic force microscope or another scanning microscope. The obtained carbon material has at least one round bend having a width of 0.1-10 nm and at least one flap region having a triangular, rectangular or still differently polygonal shape in plan view. When the carbon atom layer(s) is bent with very small radii of curvature, a finely striped ridge-and-groove structure appears in the round bend. The physical properties of the obtained carbon material are uniquely determined by the direction(s) of bending, width of each bend, shape and size of each flap region and the stripe pitch of the ridge-and-groove structure.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: May 6, 1997
    Assignee: NEC Corporation
    Inventors: Thomas Ebbesen, Hidefumi Hiura, Katsumi Tanigaki