Patent ID: 7102736

Claim:
A method of calibrating a measurement system configured to measure a position of a table in a plane substantially parallel to a principal surface of a substrate carried by the table, said method comprising: measuring, with a first part of a measurement system, each of a plurality of exposure positions of a table along each of two orthogonal axes in the plane; exposing a mark onto the substrate at each of the plurality of exposure positions; for each of said marks, and for a first orientation of the substrate with respect to the table, using a second part of the measurement system different than the first part to measure along each of the two orthogonal axes a measurement position of the table corresponding to a location of the mark; for each of said marks, and for a second orientation of the substrate with respect to the table different than the first orientation, using the second part of the measurement system to measure along each of the two orthogonal axes a second measurement position of the table corresponding to a location of the mark; recording said measured exposure, measurement, and second measurement positions; and based on said recorded positions, obtaining a characterization of a position measurement error of the measurement system along one of the orthogonal axes as a function of position along both of the orthogonal axes.