Patents by Inventor Kouzi Takahata

Kouzi Takahata 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: 5949078
    Abstract: An electron gun for emitting an electron beam traveling along a beam axis includes a cathode having a tip, the tip having substantially a circular conic shape and a tip surface substantially at the beam axis, the cathode being applied with a first voltage, an anode having a first aperture substantially on the beam axis and being applied with a second voltage higher than the first voltage, a control electrode having a second aperture substantially on the beam axis and being applied with a voltage lower that the first voltage to control a current of the cathode, the second aperture being larger than the tip surface, a guide electrode having a third aperture substantially on the beam axis, being arranged between the cathode and the anode, and being applied with a voltage higher than the first voltage and lower than the second voltage, the third aperture being smaller than the tip surface, and a lens electrode having a fourth aperture substantially on the beam axis, being arranged between the guide electrode and
    Type: Grant
    Filed: August 7, 1998
    Date of Patent: September 7, 1999
    Assignee: Fujitsu Limited
    Inventors: Yoshihisa Ooaeh, Tomohiko Abe, Akio Yamada, Hiroshi Yasuda, Kenj Kudoh, Kouzi Takahata
  • Patent number: 5895924
    Abstract: A charged particle beam exposure method is adapted to an exposure apparatus which includes a plurality of exposure systems that simultaneously expose the same pattern. The method includes the steps of (a) generating, by a pattern generating unit in each exposure system, data related to patterns which are to be exposed, (b) deflecting, by a column unit in each exposure system, a charged particle beam onto an object which is mounted on a stage by deflecting the charged particle beam based on the data generated by the pattern generating unit in a corresponding exposure system, and (c) detecting an abnormality in the exposure apparatus during operation of the exposure apparatus based on data which are obtained from corresponding parts of the exposure systems.
    Type: Grant
    Filed: February 16, 1996
    Date of Patent: April 20, 1999
    Assignee: Fujitsu Limited
    Inventors: Hiroshi Yasuda, Akio Yamada, Kazushi Ishida, Tohru Ikeda, Kouzi Takahata
  • Patent number: 5872366
    Abstract: An electron gun for emitting an electron beam traveling along a beam axis includes a cathode having a tip, the tip having substantially a circular conic shape and a tip surface substantially at the beam axis, the cathode being applied with a first voltage, an anode having a first aperture substantially on the beam axis and being applied with a second voltage higher than the first voltage, a control electrode having a second aperture substantially on the beam axis and being applied with a voltage lower than the first voltage to control a current of the cathode, the second aperture being larger than the tip surface, a guide electrode having a third aperture substantially on the beam axis, being arranged between the cathode and the anode, and being applied with a voltage higher than the first voltage and lower than the second voltage, the third aperture being smaller than the tip surface, and a lens electrode having a fourth aperture substantially on the beam axis, being arranged between the guide electrode and
    Type: Grant
    Filed: August 8, 1997
    Date of Patent: February 16, 1999
    Assignee: Fujitsu Limited
    Inventors: Yoshihisa Ooaeh, Tomohiko Abe, Akio Yamada, Hiroshi Yasuda, Kenj Kudoh, Kouzi Takahata