Patent ID: 8554510
Filing Date: 2013-10-08
Classification: G03F

Abstract:
1. A method of measuring properties of dynamic positioning errors in a lithographic apparatus arranged to transfer a pattern from a patterning device onto a substrate, the lithographic apparatus comprising a patterning subsystem for receiving said patterning device and applying said pattern to a portion of said substrate held at a patterning location, a substrate support for holding the substrate while said pattern is applied, and a positioning system for moving said substrate support, said patterning subsystem and said patterning device relative to each other in a sequence of movements such that said pattern is applied at a desired position on the substrate, said sequence of movements inherently including dynamic positioning errors on one or more axes which cause corresponding errors which can be measured in the applied pattern, the method comprising: operating the patterning subsystem and positioning system while imposing a dynamic positioning error having a known frequency content, the character of the injected error being controlled so as to be different in one or more characteristics, at different times during operation; measuring, directly or indirectly, variations in said patterning error associated with each different time of operation; and calculating, from the measured patterning error variations and known characteristics of each associated imposed error, at least one property of the inherent dynamic positioning error in a frequency band correlated with the known frequency content of the imposed error.