Patents by Inventor Kikuo Douta

Kikuo Douta 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: 4614706
    Abstract: A film of a photoresist having phenolic hydroxyl groups is irradiated with far-ultraviolet radiation, and is thereafter developed with an alkaline aqueous solution. Using as a mask a resist pattern thus obtained, dry etching is carried out to form a microscopic pattern. Since the photoresist is highly immune against the dry etching, the microscopic pattern can be formed at a high precision. By adding an azide of a specified structure, the photoresist has its sensitivity to the far-ultraviolet radiation enhanced more.
    Type: Grant
    Filed: May 2, 1984
    Date of Patent: September 30, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Toshiharu Matsuzawa, Takao Iwayanagi, Kikuo Douta, Hiroshi Yanazawa, Takahiro Kohashi, Saburo Nonogaki
  • Patent number: 4536421
    Abstract: A negative photoresist having benzene rings is irradiated with short-wavelength ultraviolet radiation, and is developed to form a photoresist pattern whose sectional shape is an inverted trapezoid. Using the photoresist pattern, the lift-off process having heretofore required troublesome steps can be performed very easily.
    Type: Grant
    Filed: July 30, 1981
    Date of Patent: August 20, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Toshiharu Matsuzawa, Kikuo Douta, Takao Iwayanagi, Hiroshi Yanazawa
  • Patent number: 3957609
    Abstract: A thin film mask having a predetermined pattern is formed directly on a thin, transparent, conductive SnO.sub.2 film formed on a dielectric substrate in order to form a fine pattern of the transparent, conductive film and that part of the transparent conductive film which is not covered by the mask is etched away through the bombardment with ions of gas accelerated under the influence of an RF electric field. Suitable masks include photoresists, aluminum, chromium, and manganese.
    Type: Grant
    Filed: September 12, 1974
    Date of Patent: May 18, 1976
    Assignee: Hitachi, Ltd.
    Inventors: Akira Sasano, Kikuo Douta, Mikio Ashikawa
  • Patent number: 3942982
    Abstract: In selectively etching a solid oxide thin film which has chemisorbed water (surface hydroxyl groups) in its surface, the thin film is surface-treated with an organic compound which has within its molecule a functional group to react with the surface hydroxyl groups. Thereafter, photo-etching is performed by the conventional method by applying a thin film of a photosensitive organic polymer onto the treated thin film. Through selection of the sort of the organic compound, the degree of side-etch arising in the process of the selective etch can be controlled.
    Type: Grant
    Filed: May 6, 1974
    Date of Patent: March 9, 1976
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Yanazawa, Norikazu Hashimoto, Mikio Ashikawa, Kikuo Douta