POSITION MEASURING METHOD AND POSITIONING METHOD OF MOVING STAGE AND THEIR EQUIPMENT

摘要

PURPOSE:To continuously obtain accurate values when the uneven form of a Y mirror (X mirror) is measured, by continuously monitoring, correcting and measuring the yaw generated when a stage is moved in the X direction (Y direction), with two noncontact displacement meters which continuously radiate parallel beams in the X direction (Y direction). CONSTITUTION:A stage 5 is moved in the X (or Y) direction and rotated around the Z axis vertical to the X-Y plane, in the manner in which the distances measured by two noncontact displacement meters 81X, 82X for an X mirror (or 81Y, 82Y for a Y mirror) become continuously equal. At the same time, by using either one of the noncontact displacement meters 81Y, 82Y for the Y mirror (or 81X, 82X for the X mirror), the uneven form is measured and stored in the mirror long axis direction. In the similar manner, the uneven form of the reflecting surface of the X (or Y) mirror is measured and stored in the mirror long axis direction. The coordinate position of the stage 5 is expressed by the coordinate values subjected to addition and correction by the obtained uneven form coordinate values in the coordinate.