Stage apparatus which supports interferometer, stage position measurement method, projection exposure apparatus, projection exposure apparatus maintenance method, semiconductor device manufacturing method, and semiconductor manufacturing factory

摘要

A stage apparatus on which a laser interferometer is mounted includes a reticle stage (1) movable in three, X-, Y-, and theta-axes, laser heads (8a-8d) each for generating a laser beam, interferometers (9a-9d) each of which is mounted on the stage (1) and splits the laser beam into reference and measurement beams, bar mirrors (11a-11c) each of which is arranged outside the stage (1) and reflects the measurement beam, and detectors (10a-10c) each for detecting the interference beam of the reference and measurement beams.