Method and apparatus for enhancing illumination uniformity in wa

Details Method and apparatus for enhancing illumination uniformity in wa Method and apparatus for enhancing illumination uniformity in wa

1989-10-05

1991-10-08

Hayes, Monroe H.

Photocopying

Projection printing and copying cameras

Step and repeat

355 71, 355 80, G03B 2742

Patent

active

050558714

ABSTRACT:
Enhanced uniformity of illumination is achieved in photolithography by interposing photochromic glass in the light path between the illuminator light source and a semiconductor wafer. In one embodiment of the invention, the photochromic glass is disposed immediately adjacent and before (upstream of) the mask. In another embodiment of the invention, the photochromic glass is disposed upstream of the mask, and an intermediate lens is disposed between the photochromic glass and the mask. In a still further embodiment of the invention, the photochromic glass is disposed in a reflector behind the illuminator light source. In other embodiments of the invention. The photochromic glass is disposed downstream of the mask. In yet another embodiment of the invention, the photochromic glass is exposed by two or more copies of a mask on a reticle to effect averaging. The photochromic glass is then used as a virtual mask to expose the wafer. Each of the described embodiments has its own advantages. Method and apparatus are disclosed.

REFERENCES:
patent: 2420636 (1947-05-01), Yule
patent: 3160504 (1964-12-01), Montani
patent: 3436353 (1969-04-01), Dreyer et al.
patent: 3441346 (1969-04-01), Naidich et al.
patent: 3598471 (1971-08-01), Baldwin et al.
patent: 3680956 (1972-08-01), Custer
patent: 3758207 (1973-09-01), Letzer
patent: 4025191 (1977-05-01), Seward

Affiliated with

Also associated with

Rating

Method and apparatus for enhancing illumination uniformity in wa does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and apparatus for enhancing illumination uniformity in wa, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for enhancing illumination uniformity in wa will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-260060