Single-pass and multi-pass interferometery systems having a dynamic beam-steering assembly for measuring distance, angle, and dispersion

摘要

The invention features an interferometry system which includes at least one dynamic beam steering assembly for redirecting one or more beams within the interferometry system in response to changes in the angular orientation or position of the measurement object. A control circuit controls the beam steering assembly based on a signal derived from one or more beams within the interferometry system. The dynamic beam steering assembly can be incorporated into interferometry systems that measure displacement, angle, and/or dispersion. The interferometry systems can be advantageously incorporated into lithography systems used to fabricate integrated circuits and other semiconducting devices and beam writing systems used to fabricate lithography masks.