Lithographic apparatus and device manufacturing method

A lithographic apparatus comprising:

• an illumination system configured to condition a radiation beam;
• a support structure constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam;
• a substrate table constructed to hold a substrate;
• a projection system configured to project the patterned radiation beam onto a target portion of the substrate;
• an interferometer system for measuring a position of the substrate table at a sampling frequency,
• a position control system configured to control the position of the support structure and the substrate table on the basis of the position measurement of the interferometer system, the position control system comprising a control path from a substrate table position controller to a support structure position controller for a substrate table position error, wherein a difference between the substrate table position error and the support structure position error is smaller than the substrate table position error for frequencies below a threshold frequency,
• wherein said position control system is configured to select a substrate table speed such that a sampled disturbance frequency generated by optical feedback in the interferometer system does not exceed said threshold frequency.

A device manufacturing method, comprising:

• transferring a pattern from a patterning device onto a substrate;
• supporting the patterning device with a support structure;
• holding the substrate on a substrate table;
• measuring a position of the substrate table with an interferometer system;
• controlling the position of the support structure and the substrate table on the basis of the position measurement of the interferometer system, and
• selecting a substrate table speed to prevent a positioning error due to a disturbance frequency generated by optical feedback in the interferometer system.

A device manufacturing method, comprising:

• transferring a pattern from a patterning device onto a substrate;
• supporting the patterning device with a support structure;
• holding the substrate on a substrate table;
• measuring a position of the substrate table by an interferometer system at a sampling frequency;
• controlling the position of the support structure and the substrate table on the basis of the position measurement of the interferometer system, the position control system comprising a control path from a substrate table position controller to a support structure position controller for a substrate table position error, wherein a difference between the substrate table position error and a support structure position error is smaller than the substrate table position error for frequencies below a threshold frequency, and
• selecting a substrate table speed such that a sampled disturbance frequency generated by optical feedback in said interferometer system does not exceed said threshold frequency.