Lithographic apparatus and device manufacturing method

A lithographic apparatus comprising:

• a support constructed to support a patterning device, the patterning device being capable of imparting a beam of radiation with a pattern in its cross-section to form a patterned beam of radiation;
• a substrate table constructed to hold a substrate;
• a projection system configured to project the patterned beam of radiation onto a target portion of the substrate;
• and
• a position measurement system configured to measure a position quantity of a movable object in a measurement direction, the position measurement system comprising
• a radiation source configured to emit a radiation beam,
• a beam splitter configured to split the radiation beam in a measurement beam and a reference beam,
• a first reflective surface mounted on the movable object configured to receive the measurement beam,
• a second reflective surface mounted on a reference object configured to receive the reference beam, and
• a detector arranged to receive a first reflected beam reflected by the first reflective surface and a second reflected beam reflected by the second reflective surface, the detector configured to provide a signal representative of the position quantity of the movable object on the basis of the first and the second beam,
• wherein the radiation source and the detector are mounted on an object that is different from the movable object and the reference object.

A lithographic apparatus comprising:

• a support constructed to support a patterning device, the patterning device being capable of imparting a beam of radiation with a pattern in its cross-section to form a patterned beam of radiation;
• a substrate table constructed to hold a substrate;
• a projection system configured to project the patterned beam of radiation onto a target portion of the substrate,
• a position measurement system configured to measure a position quantity of a movable object in a measurement direction, the position measurement system comprising
• a radiation source to emit a radiation beam,
• a first reflective and/or diffractive surface mounted on the movable object configured to receive a measurement beam,
• a second reflective and/or diffractive surface mounted on a reference object configured to receive a reference beam, and
• a detector arranged to receive a first beam from the first reflective and/or diffractive surface and a second beam from the second reflective and/or diffractive surface, the detector configured to provide a signal representative of the position quantity of the movable object on the basis of the first and the second beam,
• wherein the radiation source and the detector are arranged on a balance mass of a stage system of the support or substrate table.