Patent ID: 8731273

Claim:
A method for measuring the relative local position error of one of the sections of an object that is exposed section by section, in particular of a lithography mask or of a wafer, each exposed section having a plurality of measurement marks, wherein a) a region of the object which is larger than the one section is imaged in magnified fashion and is detected as an image; b) position errors of the measurement marks contained in the detected image are determined on the basis of the detected image; c) corrected position errors are derived by position error components which are caused by the magnified imaging and detection being extracted from the determined position errors of the measurement marks; and d) the relative local position error of the one section is derived on the basis of the corrected position errors of the measurement marks; wherein, in step c), a high-pass filtering is carried out for deriving the corrected position errors, and a function which changes more slowly than the expected changes in the determined position errors of the measurement marks at the section boundaries is fitted to the position errors determined and then, for each position error determined, the function value of the fitted function for the corresponding measurement mark is subtracted in order to obtain the corrected position error.