Patents by Inventor Shigeru Kokubo

Shigeru Kokubo 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: 8772735
    Abstract: A charged particle beam apparatus includes a field emission electron source, electrodes for applying an electric field to the field emission electron source, and a vacuum exhaust unit for keeping the pressure around the field emission electron source at 1×10?8 Pa or less. The apparatus uses electron beams emitted to have an electron-beam-center radiation angle of 1×10?2 sr or less, and uses the electric current thereof, the second order differentiation of which is negative or zero with respect to time, and which reduces at a rate of 10% or less per hour. A heating unit is provided for the field emission electron source, and a detection unit is provided for the electric current of the electron beam. The field emission electron source is repeatedly heated to keep the electric current of the electron beam to be emitted, at a predetermined value or higher.
    Type: Grant
    Filed: November 1, 2012
    Date of Patent: July 8, 2014
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Keigo Kasuya, Takashi Ohshima, Souichi Katagiri, Shigeru Kokubo, Hideo Todokoro
  • Patent number: 8766542
    Abstract: The disclosed charged particle beam apparatus includes a field-emission electron source including <310> single crystal of tungsten; a vacuum chamber having the electron source therein; an exhausting system for exhausting the vacuum chamber; a filament connected to the electron source to let flow a current through the electron source and thereby heat the electron source; a power supply for letting a current flow through the filament; an ammeter for measuring a total current emitted from the electron source; and a controlling unit for exercising control to cause the power supply to let a current flow through the filament when the total current measured periodically has become a predetermined ratio or less as compared with a total current from the electron source found immediately after first electron beam emission, or a total current from the electron beam found immediately after a current is let flow through the filament.
    Type: Grant
    Filed: January 19, 2011
    Date of Patent: July 1, 2014
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Boklae Cho, Shigeru Kokubo, Hisaya Murakoshi, Hisao Nitta
  • Publication number: 20130200788
    Abstract: The disclosed charged particle beam apparatus includes a field-emission electron source including <310> single crystal of tungsten; a vacuum chamber having the electron source therein; an exhausting system for exhausting the vacuum chamber; a filament connected to the electron source to let flow a current through the electron source and thereby heat the electron source; a power supply for letting a current flow through the filament; an ammeter for measuring a total current emitted from the electron source; and a controlling unit for exercising control to cause the power supply to let a current flow through the filament when the total current measured periodically has become a predetermined ratio or less as compared with a total current from the electron source found immediately after first electron beam emission, or a total current from the electron beam found immediately after a current is let flow through the filament.
    Type: Application
    Filed: January 19, 2011
    Publication date: August 8, 2013
    Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION
    Inventors: Boklae Cho, Shigeru Kokubo, Hisaya Murakoshi, Hisao Nitta
  • Publication number: 20130063029
    Abstract: Provided is a charged particle beam apparatus, which can emit a stable electron beam, having high brightness and a narrow energy width. The charged particle beam apparatus comprises a field emission electron source, electrodes for applying an electric field to the field emission electron source, and a vacuum exhaust unit for keeping the pressure around the field emission electron source at 1×10?8 Pa or less. The apparatus is so constituted as to use such one of the electron beams emitted as has an electron-beam-center radiation angle of 1×10?2sr or less, and to use the electric current thereof, the second order differentiation of which is negative or zero with respect to the time, and which reduces at a rate of 10% or less per hour. The charged particle beam apparatus further comprises a heating unit for the field emission electron source, and a detection unit for the electric current of the electron beam.
    Type: Application
    Filed: November 1, 2012
    Publication date: March 14, 2013
    Inventors: Keigo KASUYA, Takashi OHSHIMA, Souichi KATAGIRI, Shigeru KOKUBO, Hideo TODOKORO
  • Patent number: 8319193
    Abstract: Provided is a charged particle beam apparatus, which can emit a stable electron beam, having high brightness and a narrow energy width. The charged particle beam apparatus comprises a field emission electron source, electrodes for applying an electric field to the field emission electron source, and a vacuum exhaust unit for keeping the pressure around the field emission electron source at 1 10?8 Pa or less. The apparatus is so constituted as to use such one of the electron beams emitted as has an electron-beam-center radiation angle of 1×10?2sr or less, and to use the electric current thereof, the second order differentiation of which is negative or zero with respect to the time, and which reduces at a rate of 10% or less per hour. The charged particle beam apparatus further comprises a heating unit for the field emission electron source, and a detection unit for the electric current of the electron beam.
    Type: Grant
    Filed: June 10, 2009
    Date of Patent: November 27, 2012
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Keigo Kasuya, Takashi Ohshima, Souichi Katagiri, Shigeru Kokubo, Hideo Todokoro
  • Publication number: 20120104272
    Abstract: The present invention provides a charged particle gun including: a charged particle source (1); an extraction electrode (2); an opening (14) through which a charged particle beam passes; and a barrier provided in an area defined by connecting the charged particle source to the opening, the barrier serving to prevent molecules existing in a downstream vacuum chamber from passing through the opening to adsorb onto the charged particle source. Accordingly, the molecules existing in the downstream lower-vacuum chamber can be prevented from adsorbing onto the charged particle source, so that current noise can be reduced. This enables stable operations of the charged particle beam gun and a charged particle beam device including the charged particle beam gun.
    Type: Application
    Filed: June 11, 2010
    Publication date: May 3, 2012
    Inventors: Boklae Cho, Shigeru Kokubo, Hisaya Murakoshi
  • Publication number: 20110089336
    Abstract: Provided is a charged particle beam apparatus, which can emit a stable electron beam, having high brightness and a narrow energy width. The charged particle beam apparatus comprises a field emission electron source, electrodes for applying an electric field to the field emission electron source, and a vaccume exhaust unit for keeping the pressure around the field emission electron source at 1 10?8 Pa or less. The apparatus is so constituted as to use such one of the electron beams emitted as has an electron-beam-center radiation angle of 1 10?2 str or less, and to use the electric current thereof, the second order differentiation of which is negative or zero with respect to the time, and which reduces at a rate of 10% or less per hour. The charged particle beam apparatus further comprises a heating unit for the field emission electron source, and a detection unit for the electric current of the electron beam.
    Type: Application
    Filed: June 10, 2009
    Publication date: April 21, 2011
    Inventors: Keigo Kasuya, Takashi Ohshima, Souichi Katagiri, Shigeru Kokubo, Hideo Todokoro