| 摘要 |
PROBLEM TO BE SOLVED: To provide a position sensing unit capable of sensing a mark position with high precision by projecting an optimum light beam in both search and fine alignment processes. SOLUTION: A reticle alignment system RA comprises a first light projection system 41 for projecting a first alignment light L1 on a reticle R, a second light projection system 42 for projecting a second alignment light L2 on the reticle R different from the first alignment light L1 in terms of quantity of light per unit area and coverage, a controller making the second light projection system 42 perform light projection while the first light projection system 41 is performing light projection, and a low-power alignment microscope 51 and a high-power alignment microscope 52 for sensing positional data about a reticle alignment mark RM based on optical data generated by the reticle R upon being irradiated with the first and second alignment lights L1 and L2. COPYRIGHT: (C)2004,JPO |
