Method of measuring properties of dynamic positioning errors in a lithographic apparatus, data processing apparatus, and computer program product

A method of measuring a sensitivity of the performance of a lithographic process to 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:
• (m) operating the patterning subsystem and positioning system to apply a pattern to a substrate, while imposing a dynamic positioning error having a frequency matched to a null point in a natural frequency response of the lithographic apparatus, said natural frequency being related to an operating speed of the apparatus, the intensity of the injected error being controlled so as to be different at different times during operation;
• (n) measuring, directly or indirectly, variations in said patterning error associated with each different time of operation;
• and
• (o) calculating, from the measured patterning error variations and known characteristics of the associated imposed error, a sensititvity of said patterning error to the dynamic positioning error.