Projection exposure apparatus having active vibration isolator and method of controlling vibration by the active vibration isolator

摘要

A projection exposure apparatus transferring a pattern from a reticle to a wafer includes at least three vibration isolating pads, a vibration isolating stand on the vibration stand, a plurality of actuators driving the vibration isolating stand in a vertical direction, at least two stages over the vibration isolating stand, the stages mounting the wafer and the reticle, at least one displacement sensor at the vibration isolating stand and detecting a displacement of the vibration isolating stand, at least one acceleration sensor at the vibration isolating stand and detecting an acceleration and deceleration of the vibration isolating stand, a vibration control system coupled to the displacement sensors and the acceleration sensors, and controlling the actuators based on outputs of the displacement sensors and the acceleration sensor, a position measuring device positioned on the vibration isolating pads and measuring a position of the stages, and a vibration compensating system coupled to the vibration control system and receiving a command value to cancel a reaction force caused by the acceleration and deceleration of the stages in advance.