STAGE DEVICE AND EXPOSURE DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To prevent the measurement error of optical encoders which detect the height position of a work stage. SOLUTION: The height position and tilt of a plate chuck 10 holding a glass substrate is controlled by three linear motors 14. The optical encoders 15 consisting of sensor parts 15a and scale parts 15b are disposed near the respective linear motors 14 to respectively measure the height position of the plate chuck 10. The rolling quantity and pitching quantity of the scale parts 15b of the respective optical encoders 15 are calculated in accordance with the three measured values. The encodes are so constituted as to emit warning when these quantities exceed a prescribed threshold.