Catadioptric optical reduction system with high numerical apertu

Details Catadioptric optical reduction system with high numerical apertu Catadioptric optical reduction system with high numerical apertu

1993-10-08

1996-07-16

Epps, Georgia Y.

Optical: systems and elements

Lens

With reflecting element

359631, G02B 1700

Patent

active

055372600

ABSTRACT:
A catadioptric optical reduction system for use in the photolithographic manufacture of semiconductors having a concave mirror operating near unit magnification, or close to a concentric condition. A lens group before the mirror provides only enough power to image the entrance pupil at infinity to the aperture stop at or near the concave mirror. A lens group after the mirror provides a larger proportion of reduction from object to image size, as well as projecting the aperture stop to an infinite exit pupil. An aspheric concave mirror is used to further reduce high order aberrations. The catadioptric optical reduction system provides a relatively high numerical aperture of 0.7 capable of patterning features smaller than 0.35 microns over a 26.times.5 millimeter field. The optical reduction system is thereby well adapted to a step and scan microlithographic exposure tool as used in semiconductor manufacturing. Several other embodiments combine glasses of different refracting power to widen the spectral bandwidth which can be achieved.

REFERENCES:
patent: 3917399 (1975-11-01), Buzawa et al.
patent: 4896952 (1990-01-01), Rosenbluth
patent: 4953960 (1990-09-01), Williamson
patent: 5089913 (1992-02-01), Singh et al.
patent: 5212593 (1993-05-01), Williamson et al.
patent: 5220454 (1993-06-01), Ichihara et al.

Affiliated with

Also associated with

Rating

Catadioptric optical reduction system with high numerical apertu does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Catadioptric optical reduction system with high numerical apertu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Catadioptric optical reduction system with high numerical apertu will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1789260