Microlithography projection illumination device incorporates a separate radiation sensor for measuring radiation that has traveled through the same optical system as useful radiation to permit regulation and correction

摘要

Illumination device, especially for a microlithography projection illumination device has an optical system (12) for generating an illumination beam (14) and dosing instrumentation for measuring a characteristic value of the illumination beam with a radiation sensor (18). The latter is arranged outside the useful illumination beam in the dispersion region and detects light that has traveled through the same optical system as the useful or working illumination beam.