Patents by Inventor Norikazu Takado

Norikazu Takado 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).

  • Process of patterning compound semiconductor film in halogen containing etching gas
    Patent number: 5421954
    Abstract: A gallium arsenide film or an aluminum gallium arsenide film is patterned through a process sequence comprising the steps of: covering the gallium arsenide film with a mask layer of indium gallium phosphide, indium gallium arsenide or indium gallium arsenic phosphide, etching a part of the mask layer in a gaseous etchant containing chlorine gas under radiating an electron beam onto the part of the mask layer for forming an etching mask, and etching a part of the gallium arsenide in the gaseous etchant, wherein one of the composition and the thickness of the mask layer is regulated in such a manner that crystal defects due to lattice mis-match are restricted, thereby preventing the gallium arsenide film from undesirable large side etching.
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: June 6, 1995
    Assignee: NEC Corporation
    Inventors: Norikazu Takado, Shigeru Kohmoto