Patent attributes
A computer-implemented method of using a control module to control a lithographic apparatus includes pre-calculating, using a processor, a library of pupil images for a measuring spot of an object-under-test, wherein each pupil image represents a simulated structure of the object-under-test at the measuring spot given a particular set of configuration values and a particular probing wavelength used for testing the object-under-test using scatterometry. The method further includes, in response to receiving a real-time pupil image when testing the object-under-test using scatterometry, comparing, using the processor, the real-time pupil image with the library of pupil images to identify a best match from the library. The method further includes outputting a set of configuration values associated with the best match from the library.
