Excess coherence

Levenson, M. David
February 2007
Microlithography World;Feb2007, Vol. 16 Issue 1, p20
Trade Publication
The author reflects on excessive coherence in lithography. Coherence can be defined as the extent to which the exposure dose due to two features is greater or less than those that are attributable to each feature exposed separately. The two kinds of partial coherence common in lithography are transverse and longitudinal. Too much coherence of laser spectrum may result to the degradation of projected image.


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