Patents Assigned to Hoya Electronics Co., Ltd.
  • Photo-mask blank for use in lithography including a modified chromium compound
    Patent number: 4530891
    Abstract: In a photo-mask blank, a transparent substrate is covered with a shading layer including chromium and chromium carbide. On the shading layer is an antireflection layer which includes chromium and chromium nitride. The shading and the antireflection layers are deposited in the same hollow space by sputtering. The etch rate of the shading layer is adjustable to that of the antireflection layer to make both etch rates equal and, thereby, to reduce undercuts appearing at the shading layer.
    Type: Grant
    Filed: December 29, 1983
    Date of Patent: July 23, 1985
    Assignee: Hoya Electronics Co., Ltd.
    Inventors: Osamu Nagarekawa, Shigekazu Matsui