MICROLITHOGRAPHIC PROJECTION EXPOSURE APPARATUS

摘要

The disclosure relates to a microlithographic projection exposure apparatus, such as are used for the production of large-scale integrated electrical circuits and other microstructured components. The disclosure relates in particular to coatings of optical elements in order to increase or reduce the reflectivity.

主权项

1. An optical system, comprising:
a plurality of optical elements; and a plurality of antireflection coatings comprising a first antireflection coating and a second antireflection coating which is different from the first antireflection coating, wherein:
each of the plurality of optical elements supports at least one of the plurality of antireflection coatings; andwithin a first incidence angle range, the first antireflection coating has a polarisation-dependent reflectivity which is greater for s-polarised light than for p-polarised light;within a second incidence angle range, the second antireflection coating has a polarisation-dependent reflectivity which is less for s-polarised light than for p-polarised light;during use of the optical system, the first and second antireflection coatings are in a path of light as it propagates through the optical system so that polarisation-dependent differences in reflectivity of the first and second antireflection coatings at least partially compensate each other; andthe optical system is a microlithographic optical system.