Exposure method and apparatus therefor

Optical: systems and elements – Diffraction – Using fourier transform spatial filtering

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

355 53, 355 71, G02B 2746, G03B 2742, G03B 2772

Patent

active

054991374

ABSTRACT:
In an exposure method of illuminating a pattern formed on a mask with illumination light from an illumination optical system, and projecting/exposing an image of the pattern on a photosensitive substrate through a projection optical system, the pattern includes a transmission portion having a transmittance of about 1 with respect to the illumination light and a phase shift transmission portion which provides a phase difference of about (2n+1).pi. (n is an integer) with respect to the light transmitted through the transmission portion, and has a pattern width not more than a resolving limit of the projection optical system. The illumination light passing through a predetermined plane which is substantially coincident with a Fourier transform plane of the mask in the illumination optical system or a conjugate plane thereto, is limited to at least one local region having the center at a position shifted from an optical axis of the illumination optical system, thereby inclining the illumination light radiated on the mask at an angle corresponding to fineness of the pattern in a predetermined direction.

REFERENCES:
patent: 4947413 (1990-08-01), Jewell et al.
patent: 4952815 (1990-08-01), Nishi
patent: 5126220 (1992-06-01), Tokitomo et al.
patent: 5307207 (1994-04-01), Ichihara
patent: 5335044 (1994-08-01), Shiraishi

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Exposure method and apparatus therefor does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Exposure method and apparatus therefor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Exposure method and apparatus therefor will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2104800

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.