摘要 |
<p>A wafer stage is moved while monitoring a position using an X interferometer and a Y interferometer, and a Z position of a Y scale arranged on the wafer stage upper surface is measured using a surface position sensor. In this case, for example, from a difference of measurement results of two surface position sensors, tilt of the Y scale in the Y-axis direction is obtained. By measuring the tilt of the entire surface of a pair of Y scales, two-dimensional unevenness data of the scales are made. By correcting the measurement results of the position surface sensor using the unevenness data, and then using the corrected measurement results, it becomes possible to drive wafer stage WST two-dimensionally with high precision.</p> |