Object positioning in lithography

A method for positioning an object, the method comprising:

• providing a measurement system with one or more sensors configured to measure a position of the object in one or more degrees of freedom relative to a reference, wherein each of the one or more sensors of the measurement system has an associated measurement area on the object of which the position in one or more degrees of freedom relative to the reference is measured, and wherein a location of at least one measurement area on the object is dependent on the position of the object in at least one degree of freedom;
• providing an actuator system with one or more actuators configured to position the object;
• providing a set point representing a desired position of the object;
• providing a dynamic model of the object to estimate an internal dynamic behavior of the object, wherein the dynamic model includes a dependency of the location of at least one measurement area on the position of the object in at least one degree of freedom;
• estimating the internal dynamic behavior of the object using the dynamic model by providing to the dynamic model, an input to the object and the by the measurement system measured position of the object;
• compensating the output of the measurement system for the internal dynamic behavior using the estimated internal dynamic behavior;
• and
• positioning the object with the actuator system based on the set point and the by the measurement system measured position of the object while taking the internal dynamical behavior into account.

A non-transitory computer-readable medium comprising instructions, when executed, configured to cause a computer system to at least:

• obtain a measured position of an object using a measurement system, the measurement system having one or more sensors configured to measure the position of the object in one or more degrees of freedom relative to a reference, wherein each of the one or more sensors of the measurement system has an associated measurement area on the object of which the position in one or more degrees of freedom relative to the reference is measured, and wherein a location of at least one measurement area on the object is dependent on the position of the object in at least one degree of freedom;
• estimate an internal dynamic behavior of the object using a dynamic model of the object by providing to the dynamic model, an input to the object and the by the measurement system measured position of the object, the dynamic model configured to estimate the internal dynamic behavior of the object and the dynamic model including a dependency of the location of at least one measurement area on the position of the object in at least one degree of freedom;
• cause compensation of the output of the measurement system for the internal dynamic behavior using the estimated internal dynamic behavior;
• and
• output information to enable positioning of the object with an actuator system based on a set point representing a desired position of the object and the by the measurement system measured position of the object while taking the internal dynamical behavior into account.