Patents by Inventor Kiyohito Mashima

Kiyohito Mashima 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).

  • Reflective reduction imaging optical system for X-ray lithography
    Patent number: 5917879
    Abstract: A reflective reduction imaging optical system for X-ray lithography achieves good imaging performance using a simple construction. The system includes, from the side of mask M, first concave mirror G.sub.4, plane mirror G.sub.3, convex mirror G.sub.2, and second concave mirror G.sub.1 are placed, in that sequence, from the object side. The concave mirrors G.sub.4 and G.sub.1 and the convex mirror G.sub.2 are formed in aspherical shapes. The convex mirror G.sub.2 is placed at the pupil plane and the system becomes telecentric on the image side of wafer W.
    Type: Grant
    Filed: March 17, 1997
    Date of Patent: June 29, 1999
    Assignee: Nikon Corporation
    Inventor: Kiyohito Mashima