Imaging and mask-inspection system for e.g. determining amount of energy delivered by illumination source, has control unit generating signals to control illumination source and/or correction value for image evaluation of imaging beam

摘要

The system has an optical element arranged in an imaging beam path (12) in addition to an optical component, where the optical element is provided for a coupling (10) and an uncoupling (11) of a reference beam (8). A control unit (15) generates signals from intensity values, performance values or energy measurement values of the reference beam imaged on a detector (14). The signals control an illumination source (1) and/or correction value for image evaluation of an imaging beam (16) imaged on the detector.