METHOD FOR THREE-DIMENSIONALLY MEASURING A 3D AERIAL IMAGE OF A LITHOGRAPHY MASK

摘要

In a method for three-dimensionally measuring a 3D aerial image in the region around an image plane during the imaging of a lithography mask (5) arranged in an object plane (4), a selectable imaging scale ratio in mutually perpendicular directions (x, y) is taken into account. For this purpose, an electromagnetic wavefront of imaging light (1) is reconstructed after the interaction thereof with the lithography mask (5). An influencing variable corresponding to the imaging scale ratio is included. Finally, the 3D aerial image measured with the inclusion of the influencing variable is output. This results in a measuring method which can also be used to measure lithography masks which are optimized for use with an anamorphic projection optical unit during projection exposure.