Abstract:
In a method for determining one or more properties of a substrate, scatterometry spectra can be measured from one or more targets on the substrate. Reconstructions of each of said spectra can be performed to derive one or more values for the property of the substrate, by comparing representations of each of the measured spectra with one or more modeled representations of spectra calculated using variable parameter values. At least one parameter in the reconstruction for each spectrum can be linked to the value of the parameter used in the reconstruction for a different spectrum.
Abstract:
Disclosed is a system configured to project a beam of radiation onto a target portion of a substrate within a lithographic apparatus. The system comprises a mirror (510) having an actuator (500) for positioning the mirror and/or configuring the shape of the mirror, the actuator also providing active damping to the mirror, and a controller (515a, 515b) for generating actuator control signals for control of said actuator(s). A first coordinate system is used for control of said actuator(s) when positioning said mirror and/or configuring the shape of said mirror and a second coordinate system is used for control of said actuator(s) when providing active damping to said mirror.