Patent ID: 8013981

Claim:
A lithographic apparatus comprising: a projection system constructed and arranged to project a beam of radiation; a vacuum chamber containing at least part of a path of the beam; a movable table constructed and arranged to transport an object to a position in the beam path in the vacuum chamber; a first capacitor electrode and a second capacitor electrode attached to the table; a plurality of first inductor assemblies positioned along a path of movement of the movable table, each first inductor assembly configured to have a different inductance value such that the resonance frequencies of different ones of the plurality of first inductor assemblies are mutually different in the presence of the object over the first and second capacitor electrodes, wherein a first inductor assembly of the plurality of first inductor assemblies coupled to the first capacitor electrode and the second capacitor electrode, and configured to apply a voltage between the first capacitor electrode and the second capacitor electrode; and a second inductor assembly mounted at a position that remains fixed, the second inductor assembly being configured to generate a magnetic field, wherein the presence of the object on the table is detected by applying a voltage on the second inductor assembly which will result in a magnetic field which when picked up by the first inductor assembly wilt create a magnetic field response in the first inductor assembly dependent on the capacitance of the capacitor electrodes and therefore the presence of the object on the table.