A new algorithm for designing an illuminator in a proximity exposure system is discussed. A relation between aberration of an irradiating lens and the irradiance distribution is studied and it is found that the lens has to satisfy the expression:h =f tan 0 to achieve uniform distribution. We designed a new-type illuminator with irradiating lens based on this expression and used a Fresnel lens as a collimator. This illuminator has high uniformity in the distribution within over an exposure area of 650mm x 650 mm. It has a collimation angle which is desirable fOr high resolution; and, experimentally, a resolution of 5 p.m line and space pattern was observed with a gap of 50 p.m.

Date Published: 1 November 1990
PDF: 17 pages
Proc. SPIE 1333, Advanced Optical Manufacturing and Testing, (1 November 1990); doi: 10.1117/12.22820

Published in SPIE Proceedings Vol. 1333:
Advanced Optical Manufacturing and Testing
Gregory M. Sanger; Paul B. Reid; Lionel R. Baker, Editor(s)