| 摘要 |
PURPOSE:To avoide deterioration in the measurement accuracy of a jogging stage position by providing the exposure device stage wherein a coarse stage operates on a jogging stage, and this jogging stage does not influence the opera tion of the coarse stage. CONSTITUTION:The position of a coarse stage 4 relative to a jogging stage 5 is measured with a coarse stage end measuring machine 41 comprising a magnetic linear sale on the jogging stage 5. On the other hand, the shift amount of the jogging stage 5 is measured with an end measuring system 6 constituted with a mirror 61 fixed on the jogging stage 5, an interferometer 62 and a protec tive tube 63 covering a laser beam passage 64 between the mirror 61 and the interferometer 62. As the shift stroke of the jogging stage 5 is very fine, how ever, a fixed length tube of high rigidity metal is used for the protective tube 63, thereby enabling the nearly complete enclosure of the laser beam passage 64. According to the aforesaid construction, the laser beam passage 64 becomes free from an influence due to the fluctuation of the atmosphere, and the accu racy of a laser end measurement system 6 can be fully obtained. |
