Patents by Inventor Kiichi Sakamoto

Kiichi Sakamoto 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: 5148033
    Abstract: An electron beam exposure device comprises an electron gun, a mask plate provided with a plurality of apertures defining corresponding patterns, each pattern having a specific shape for forming a corresponding cross-sectional shape of an electron beam composed of charged particles incident thereon and passing therethrough, deflecting means provided both on a first side of a mask plate onto which the beam is irradiated and on a second side thereof from which the beam is emitted, for deflecting the beam from an original axis thereof so as to pass through a selected one of the apertures provided on the mask plate, and for deflecting again said beam so as to return said beam to the original axis thereof, sample holding means, focus point adjusting means provided between the mask plate and the sample holding means, and control means for controlling the focus point adjusting means.
    Type: Grant
    Filed: October 2, 1991
    Date of Patent: September 15, 1992
    Assignee: Fujitsu Limited
    Inventors: Akio Yamada, Kiichi Sakamoto
  • Patent number: 5144142
    Abstract: A blanking aperture array for use in a charged particle beam exposure has a substrate, at least m rows by n columns of apertures arranged two-dimensionally in the substrate, where each of the apertures have a pair of blanking electrodes and m and n are integers greater than one, and n m-bit shift registers provided on the substrate for applying voltages dependent on pattern data to m pairs of the blanking electrodes of the apertures in the ith column, where i=1, 2, . . . , n. The pattern data is relates to a pattern which is to be exposed using the blanking aperture array.
    Type: Grant
    Filed: May 18, 1990
    Date of Patent: September 1, 1992
    Assignee: Fujitsu Limited
    Inventors: Shunsuke Fueki, Hiroshi Yasuda, Kiichi Sakamoto, Yasushi Takahashi
  • Patent number: 5130547
    Abstract: A charged-particle beam exposure method which has a stencil mask formed with a several mask patterns, deflects a beam of charged particles to a mask pattern selected from among the several mask patterns and shapes the beam, and performs wafer exposure by deflecting the shaped beam and illuminating the same onto a wafer.
    Type: Grant
    Filed: November 21, 1990
    Date of Patent: July 14, 1992
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sakamoto, Yoshihisa Oae, Shunsuke Fueki, Akio Yamada, Hiroshi Yasuda
  • Patent number: 5118952
    Abstract: A photo cathode used for an electron image projection apparatus has a silver layer as a photo electric material and a layer of an alkali metal or alkaline earth metal, such as cesium, coated on the silver layer. The cesium is as thick as several atomic layers, and reduces the work function of the photo cathode. The silver layer may be coated all over a substrate, and portions other than the cathode may be masked by a non photoelectric metal, or non transparent metal, such as platinum. Or, the silver layer may be patterned on the layer of a non photoelectric metal coated on the substrate. An excitation light to the photo cathode may be irradiated onto the surface of the silver, or onto the back of the silver layer through a transparent substrate. After depositing the cesium layer on the silver, the layers are heated in a vacuum at 50.degree. to 200.degree. C., thus a contrast ratio, i.e. ratio of electron current from the cathode and from the non cathode portion, is achieved as high as 20.
    Type: Grant
    Filed: October 24, 1990
    Date of Patent: June 2, 1992
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sakamoto, Hiroshi Yasuda, Jinko Kudou, Akio Yamada
  • Patent number: 5117117
    Abstract: An electron beam exposure system for writing a pattern on an object by an electron beam comprises a beam source for producing an electron beam, a beam focusing unit for focusing the electron beam on the object, a beam processing unit provided along an optical axis of the electron beam for modifying the electron beam in response to control signals, a column extending along the optical axis of the electron beam so as to surround a region that includes the object, the beam source, the beam focusing unit and the beam processing unit and for maintaining the region evacuated, and an interface element mounted on the column for supplying the control signals to said beam processing unit.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: May 26, 1992
    Assignee: Fujitsu Limited
    Inventors: Yoshihisa Oae, Kiichi Sakamoto, Akio Yamada
  • Patent number: 5051556
    Abstract: A charged particle beam lithography system comprises a beam source of a charged particle beam, a beam shaping aperture for providing a predetermined cross section to the charged particle beam, a first focusing system for focusing the charged particle beam on a first crossover point located on the optical axis, a second focusing system provided between the first crossover point and an object for focusing the charged particle beam on a second crossover point located on the optical axis, a beam deflection system for deflecting the electron beam such that the beam is moved over the surface of the object, a stage for supporting the object, a mask provided in a vicinity of said first focusing system, and addressing system for selectively deflecting the charged particle beam such that the charged particle beam is passed through a selected aperture on the mask, wherein the addressing system comprises an electrostatic deflector for variable shaping of the charged particle beam and an electromagnetic deflector for defl
    Type: Grant
    Filed: October 31, 1989
    Date of Patent: September 24, 1991
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sakamoto, Hiroshi Yasuda, Akio Yamada
  • Patent number: 5036209
    Abstract: A charged particle beam exposure apparatus includes a charged particle beam generator, a deflector device for deflecting the charged particle beam electromagnetically to individually illuminate small areas of a pattern forming region formed on a transparent mask, apparatus for moving the transparent mask mechanically, and the various components required for reducing the charged particle beam pattern through the mask and projecting the same onto a semiconductor device substrate to be exposed. A semiconductor device is fabricated using such apparatus by moving the mask mechanically to position a pattern forming region at a predetermined exposure position. The pattern forming region includes a plurality of small areas which can be individually selected by deflecting the charged particle beam when the pattern forming region is positioned at the exposure position. Each individual area is of a size such that the entirety thereof is exposed when the beam is deflected onto such area.
    Type: Grant
    Filed: October 20, 1989
    Date of Patent: July 30, 1991
    Assignee: Fujitsu Limited
    Inventors: Toyotaka Kataoka, Kiichi Sakamoto
  • Patent number: 5029222
    Abstract: A photoelectron image projection apparatus has a device for detecting an image of a pattern of a mask within a predetermined projection region of the mask. An image signal describing the detected image is compared with a reference image signal which is known from the pattern of the mask, and a defect in the projection pattern is detected when the two compared image signals differ.
    Type: Grant
    Filed: August 30, 1988
    Date of Patent: July 2, 1991
    Assignee: Fujitsu Limited
    Inventors: Akio Yamada, Hiroshi Yasuda, Kiichi Sakamoto, Jinko Kudou
  • Patent number: 5023462
    Abstract: A photo-cathode image projection apparatus includes a light source for producing an optical beam, a photoelectron mask disposed so as to be irradiated by the optical beam and a photoelectron mask patterned according to a desired pattern with a material that emits photoelectrons in response to irradiation by an optical beam. The apparatus also includes a focusing device for focusing the emitted photoelectrons to form a photoelectron beam focused on the object, an acceleration electrode disposed along the path of the photoelectron beam for accelerating the photoelectrons in the beam, an elongated passage defined in the acceleration electrode to permit passage of a part of the photoelectron beam, and a stage disposed for supporting the object in a position such that the focused photoelectron beam is focused on the object. Also included is a voltage source for applying an acceleration voltage between the photoelectron mask and the acceleration electrode.
    Type: Grant
    Filed: March 23, 1989
    Date of Patent: June 11, 1991
    Assignee: Fujitsu Limited
    Inventors: Akio Yamada, Kiichi Sakamoto, Jinko Kudou, Hiroshi Yasuda
  • Patent number: 4980567
    Abstract: In a charged particle beam exposure system, a line of individual blanking apertures (39.sub.0 to 39.sub.255) is provided to form a line of beams which are individually blanked and unblanked by applying voltages to electrodes within the blanking apertures.
    Type: Grant
    Filed: March 28, 1989
    Date of Patent: December 25, 1990
    Assignee: Fujitsu Limited
    Inventors: Hiroshi Yasuda, Junichi Kai, Toyotaka Kataoka, Yasushi Takahashi, Shinji Miyaki, Kiichi Sakamoto
  • Patent number: 4954717
    Abstract: A photoelectron mask for photo cathode image projection includes a transparent substrate, and a pattern formed on a main surface of the transparent substrate. The pattern includes a non-transparent material. The mask also includes a photoelectron emission film formed so as to cover the main surface of the transparent substrate on which the pattern is formed. The photoelectron emission film includes a material selected from the group consisting of pure platinum, a platinum-rich material containing platinum as the major component, and a platinum compound.
    Type: Grant
    Filed: December 13, 1988
    Date of Patent: September 4, 1990
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sakamoto, Hiroshi Yasuda, Akio Yamada, Jinko Kudou