| 摘要 |
PROBLEM TO BE SOLVED: To provide a balanced positioning system capable of absorbing a factor of vibration such as reactive force, especially yaw moment generated when a mask or substrate table is driven, as a main factor of degrading accuracy in a lithography projection system. SOLUTION: A mask table MT movable on a XY plane freely for holding a mask is supported on two balanced masses 20 and 30 supported and moveable freely in at least Y direction against a base of the projection system. For positioning the mask, the mask table MT is driven in Y direction by driving units 18 and 17 operated between the mask table MT and the balance masses 20 and 30, and also driven in the X direction by a unit 19, while the reactive force is absorbed by the balanced masses. If these driving units are driven mutually, torque necessary for counterbalancing the yaw movement is obtained. |
