Patent ID: 8730474

Claim:
A method for measuring masks for photolithography, in which structures to be measured on a mask on a movable mask carrier are illuminated and imaged as an aerial image onto a detector, the illumination being set in a manner corresponding to the illumination in a photolithography scanner during a wafer exposure, a selection of positions at which the structures to be measured are situated on the mask is predetermined, a constant distance between the movable mask carrier and a sensor head is maintained, in which the sensor head is coupled to a scanning head that scans a scale to determine a position of the scanning head, from which a position of the mask is determined, the positions in the selection on the mask are successively brought to a focus of an imaging optical system and in each case imaged as a magnified aerial image onto the detector, the aerial images being stored, and structure properties are analyzed by means of predetermined evaluation algorithms.