Patents by Inventor Masahito Hiratsuka

Masahito Hiratsuka 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).

  • Plasma processing apparatus
    Patent number: 5271788
    Abstract: A magnetron plasma etching apparatus comprises a suscepter serving as an electrode on which a silicon wafer is mounted. A carbon ring having an outer diameter larger than the diameter of the wafer and an electrical resistance lower than that of the wafer, is arranged around the suscepter. The carbon ring is electrically connected to the suscepter. The carbon ring improves uniformity of etching of the wafer.
    Type: Grant
    Filed: July 23, 1992
    Date of Patent: December 21, 1993
    Assignees: Tokyo Electron Limited, Kabushiki Kaisha Toshiba
    Inventors: Makoto Hasegawa, Takaya Matsushita, Keiji Horioka, Isahiro Hasegawa, Toshihisa Nozawa, Yoshio Ishikawa, Masahito Hiratsuka, Satoshi Kaneko
  • Dry etching method
    Patent number: 5259923
    Abstract: A dry etching method, wherein a multilayer film including one selected from tungsten, molybdenum, and a silicide thereof, as the first layer, and polycrystal silicon as the second layer underlying is formed on a silicon oxide insulation film, a substrate having a mask pattern on the multilayer film is placed in a vacuum container, an etching gas is introduced into the vacuum container, and an electrical discharge is induced by applying an electrical field to the vacuum container, thereby anisotropically etching the multilayered film in accordance with the mask pattern.
    Type: Grant
    Filed: May 28, 1992
    Date of Patent: November 9, 1993
    Assignee: Tokyo Electron Limited
    Inventors: Masaru Hori, Keiji Horioka, Haruo Okano, Masao Ito, Masahito Hiratsuka, Yoshio Ishikawa