| 摘要 |
An exposure apparatus wherein a semiconductor wafer is exposed to an IC circuit pattern formed on a mask through a reduction projection optical system, and then the wafer is stepped; and these operations are alternately repeated, thereby forming a plurality of patterns on the wafer. A distance measuring system utilizing the interference between laser beams, has a first mirror fixed relative to the mask and another mirror fixed relative to the wafer, so that the relative position between the mask and the wafer is determined by a single interferometer system. |
