Birefringence mapping of fused silica samples is used to measure density change in the material after exposure to excimer laser radiation. The proper techniques and methods that should be used to perform the exposure of the samples and the analysis of the birefringence results will be discussed. The quantitative analysis of birefringence measurements includes the correct subtraction of the initial birefringence of the sample and the comparison with a theoretical birefringence map calculated for a 1 ppm unconstrained density change under consideration of material and exposure parameters. Proper experimental conditions include the use of samples with low initial birefringence and a round circularly polarized laser beam with top-hat intensity profile.

Date Published: 28 May 2004
PDF: 6 pages
Proc. SPIE 5377, Optical Microlithography XVII, (28 May 2004); doi: 10.1117/12.534286

Published in SPIE Proceedings Vol. 5377:
Optical Microlithography XVII
Bruce W. Smith, Editor(s)