Patents by Inventor Tsuneo Okubo

Tsuneo Okubo 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: 4489241
    Abstract: An exposure method with an electron beam exposure apparatus in which an electron beam is emitted onto a substrate such as a silicon wafer on which an electron-beam sensitive resist is coated, thereby directly forming or writing patterns. A substrate having thereon a number of chips are divided into blocks, which each contain a plurality of chips. Marks are provided on each of the blocks, the positions of the marks are detected and the writing exposure positions of the chips within each block are modified on the basis of the detection results. According to this invention, efficient writing exposure can be made with high accuracy.
    Type: Grant
    Filed: June 9, 1982
    Date of Patent: December 18, 1984
    Assignees: Hitachi, Ltd., Nippon Telegraph & Telephone Public Corporation
    Inventors: Tadahito Matsuda, Tsuneo Okubo, Susumu Ozasa, Norio Saitou, Haruo Yoda
  • Patent number: 4443703
    Abstract: A method and apparatus of deflection calibration for a charged particle beam exposure apparatus having an electromagnetic deflector and an electrostatic deflector both for deflecting a charged particle beam and a movable stage structure. The electromagnetic deflector is previously subjected to a calibration operation known per se. With a fiducial mark positioned in a predetermined location, the beam is deflected by the calibrated electromagnetic deflector instead of moving the stage structure, the beam is then deflected by the electrostatic deflector to detect the location of the fiducial mark, and deflection data are measured of the electrostatic deflection for the detection of the location of the fiducial mark. According to the present invention the calibration is performed in a short time without causing degradation of the precision of, e.g., lithography due to heat generated by movement of the stage structure.
    Type: Grant
    Filed: February 10, 1982
    Date of Patent: April 17, 1984
    Assignees: Nippon Telegraph & Telephone Public Corporation, Hitachi, Ltd.
    Inventors: Nobuo Shimazu, Tsuneo Okubo, Norio Saitou, Susumu Ozasa
  • Patent number: 4336597
    Abstract: A method of measuring the diameter of an electron beam in which the electron beam diameter is measured from the leading edge or trailing edge of a detector signal that is obtained as the mark area formed on the specimen is scanned by the electron beam. This method comprises the following steps: scanning the specimen by the electron beam at least once to find the maximum and minimum values of the detector signal; setting two threshold levels based on the maximum and minimum values; scanning the mark area by the electron beam to measure the time interval during which the level of the detector signal is within the two threshold levels; and calculating the beam diameter.
    Type: Grant
    Filed: June 26, 1980
    Date of Patent: June 22, 1982
    Assignees: Nippon Telegraph and Telephone Public Corp., Hitachi, Ltd.
    Inventors: Tsuneo Okubo, Yasuo Kato, Genya Matsuoka
  • Patent number: 4286154
    Abstract: This invention relates to a method of detecting a mark by an electron beam, the mark being provided on a sample, which includes the steps of scanning the electron beam over an area of the mark in such a manner that the electron beam is subjected to chopping by sampling pulses having a higher frequency than the scanning frequency, eliminating a component of noise from a detected signal representative of the mark, synchronously rectifying the detected mark signal, binary-coding the detected mark signal as compared with a suitable threshold value, and detecting a position of the mark by using the binary-coded signal.
    Type: Grant
    Filed: November 26, 1979
    Date of Patent: August 25, 1981
    Assignees: Hitachi, Ltd., Nippon Telegraph & Telephone Public Corporation
    Inventors: Tsuneo Okubo, Nobuo Hamamoto, Kazuo Ichino
  • Patent number: 3983097
    Abstract: High molecular derivatives (1) including at least a recurring structural formula: ##SPC1##(wherein R means an organic residue except for 2,4-dinitrophenyl radical in its backbone or side chain) are produced by subjecting a polymer (2) including at least a recurring structural unit of the formula: ##SPC2##And an amino-containing organic substance (3) of the general formula:RNH.sub.2(wherein R has the meaning defined above) to a substitution reaction in a suitable liquid reaction medium and under neutral to alkaline conditions.
    Type: Grant
    Filed: February 21, 1975
    Date of Patent: September 28, 1976
    Inventors: Tsuneo Okubo, Norio Ise