Metrology system and method for monitoring and correcting system generated errors

摘要

A metrology system (1) and a method for determining low order errors are disclosed. At least one measurement objective (9) for the determination of the position of structures (3) on a substrate (2) is provided. The substrate (2) to be measured rests in a support on three points of support (52). The support exhibits an opening (53) for measuring the substrate (2). At least two marks (54) are provided on the support for the mask (2) in such a way that the marks (54) are capturable with the measurement objective (9) by moving the measurement table (20). Furthermore the substrate (2) in the support does not screen the marks (54) on the support.