Patent ID: 7012398

Claim:
A scanning exposure method that exposes a pattern of a mask onto an object, the method comprising: moving a mask stage that holds the mask in a scanning direction by a first electromagnetic driver, the first electromagnetic driver having a first portion coupled to the mask stage and a second portion; detecting a position of the mask stage by a position detector that cooperates with a reflective portion of the mask stage, the reflective portion being positioned along the scanning direction; moving a counter weight that comprises a first bearing, a second bearing, and at least one beam extending along the scanning direction in a direction opposite to a movement direction of the mask stage in response to a reaction force generated by a movement of the mask stage by the first electromagnetic driver, the counter weight being heavier than the mask stage, and the at least one beam being coupled to the second portion of the first electromagnetic driver; movably supporting the counter weight by a base member having a surface extending in the scanning direction and a non-scanning direction different from the scanning direction, the base member supporting the counter weight via the first bearing; and guiding the movement of the counter weight in the scanning direction by a guide that is mounted on the base member and extends along the scanning direction, the guide guiding the movement of the counter weight via the second bearing, and a length of the guide along the scanning direction being longer than a length of the reflective portion along the scanning direction.