Method and assembly for analysing the wavefront effect of an optical system

A method for analysing the wavefront effect of an optical system, comprising:

• illuminating a measurement mask with illumination light from an illumination device;
• producing an interferogram in a specified plane using a diffraction grating from a wavefront coming from the illuminated measurement mask and traveling through the optical system;
• and
• capturing the interferogram with a detector;
• wherein different angular distributions of the illumination light that is incident on the measurement mask are produced by a mirror arrangement of independently settable mirror elements;
• wherein the optical system is a projection lens of a microlithographic projection exposure apparatus;
• and
• wherein the wavefront effect of the projection lens is ascertained in a targeted fashion by setting the mirror arrangement for pupil regions which are illuminated during operation of the projection exposure apparatus.

An arrangement for analysing the wavefront effect of an optical system, comprising:

• an illumination device, having a field facet mirror with a plurality of field facets and having a pupil facet mirror with a plurality of pupil facets, wherein the field facets are independently adjustable to produce a desired angular distribution of illumination light;
• a measurement mask on which the illumination light is incident;
• a diffraction grating, which produces a plurality of interferograms in a specified plane from respective wavefronts, each of which, during the illumination of the measurement mask with the illumination light from the illumination device, comes from the illuminated measurement mask and travels through the optical system for different angular distributions of the illumination light that is incident on the measurement mask;
• a detector configured to capture the interferograms obtained for the different angular distributions of the illumination light that is incident on the measurement mask;
• and
• one or more processors configured to calculate the respective system wavefront deviations of the optical system for pupil regions that are respectively illuminated in individual ones of the measurement steps, from a matching wavefront deviation portion in the captured interferograms;
• and
• one or more memories configured to store the respective system wavefront deviations of the optical system.