Patents by Inventor Yawara Nojima

Yawara Nojima 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: 5978072
    Abstract: An exposure apparatus illuminates a mask with exposure light emitted from an illumination optical system and projects a mask pattern image that is formed when the exposure light passes through the mask onto a photosensitive substrate. The illumination optical system includes an optical element for making the intensity distribution of exposure light emitted from the light source uniform, and aperture stops are interchangeably positioned directly behind the optical element. The illumination optical system additionally includes an adjusting mechanism that adjusts the positions and the inclination of the optical element and the aperture stops in the direction along the optical axis in directions perpendicular to the optical axis, and with respect to the inclination from the optical axis. Thus, the positional relationship between the optical element and the aperture stops can be kept constant, and as a result, the exposure accuracy of an exposure apparatus can be improved.
    Type: Grant
    Filed: May 29, 1997
    Date of Patent: November 2, 1999
    Assignee: Nikon Corporation
    Inventor: Yawara Nojima
  • Patent number: 5184196
    Abstract: A projection exposure apparatus comprises a projection optical system for forming an image of a predetermined pattern on a mask onto a photosensitive substrate under exposure light having a first wavelength, an illumination system for illuminating a mask on the photosensitive substrate with light having a second wavelength different from the first wavelength through the projection optical system so as to attain alignment, and a detection system for detecting light reflected by the mark. The illumination system comprises a light source for emitting the light having the second wavelength, a first field stop for defining an illumination field on the photosensitive substrate and a second field stop for defining an illumination field on the photosensitive substrate.
    Type: Grant
    Filed: December 19, 1991
    Date of Patent: February 2, 1993
    Assignee: Nikon Corporation
    Inventors: Masahiro Nakagawa, Hideo Mizutani, Kouichirou Komatsu, Yawara Nojima