| 摘要 |
PROBLEM TO BE SOLVED: To make feasible of performing high-accuracy base line control of a projection aligner provided with an off-axis alignment system. SOLUTION: A reference mark FM 2 to be aligned with a reticle mark and an alignment mark as well as another reference mark FM 1 to be aligned by an off-axis system are provided on a reference plate FP of wafer (WST) so as to measure the two reference marks FM 1 and 2 almost simultaneously in the stationary state of the stage. Furthermore, interferometers used at the stage position in the exposure time and off-axis alignment time are preset at the same measured value. |
