Patent Number: 6,252,667

Title: Interferometer having a dynamic beam steering assembly

Abstract: 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. For example, the control circuit can cause the beam steering assembly to redirect a measurement beam within the system such that exit measurement and reference beams used to generate an interferometric signal remain substantially parallel to one another over a range of angular orientations or translations of the measurement object. 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.

Inventors: Hill; Henry A. (Tucson, AZ), de Groot; Peter (Middletown, CT)

Assignee: Zygo Corporation

International Classification: G01B 9/02 (20060101); G03F 7/20 (20060101); G01B 009/02 ()

Expiration Date: 06/26/2018