Patent ID: 8223314
Filing Date: 2012-07-17
Classification: G01M,G03B

Abstract:
1. A method comprising: determining a first processing center position to calculate a wavefront aberration of an optical system using a first mark including a first slit and a first window which are parallel to each other and extend along a first direction, by sequentially setting the optical system in a plurality of states in which the optical system has a plurality of spherical aberration amounts, and processing first interference fringe image data formed by the first mark and the optical system in each of the plurality of states; determining a second processing center position to calculate a wavefront aberration of the optical system using a second mark including a second slit and a second window which are parallel to each other and extend along a second direction orthogonal to the first direction, by processing second interference fringe image data formed by the optical system and the second mark in each of the plurality of states; correcting the first processing center position in the first direction using the second processing center position in the first direction and correcting the second processing center position in the second direction using the first processing center position in the second direction; and calculating a wavefront aberration of the optical system by processing the first interference fringe image data using the corrected first processing center position, and processing the second interference fringe image data using the corrected second processing center position.