Patents by Inventor Itsuji Ashida

Itsuji Ashida 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).

  • Projection exposure apparatus
    Patent number: 6153877
    Abstract: An object of a inventions of the present application is raising the pattern position precision by stabilizing the temperature of a reticle or a reduction lens in a projection aligner. The projection aligner comprises a reticle stage with a reticle, a light source emitting light to the reticle, a reduction lens projecting the light onto the wafer via the reticle, and a temperature control unit controlling the temperature of the reticle or/and a reduction lens by a clean air.
    Type: Grant
    Filed: July 8, 1998
    Date of Patent: November 28, 2000
    Assignee: Oki Electric Industry Co. Ltd.
    Inventor: Itsuji Ashida