| 摘要 |
PROBLEM TO BE SOLVED: To align a reticle with a wafer with high accuracy, especially in scanning exposure-type aligners, taking relative rotation and the like into account. SOLUTION: A wafer stage control system 16 drives a wafer stage according to a command from a speed command generating means 15b. A calculating means 15c is fed with the coordinates WX1, WX2, WY1, WY2 of the four axes of the wafer stage measured by means of an interferometer 7 and the coordinates RX, RL, RR of the three axes of a reticle stage measured by means of an interferometer 14. The calculating means 15c subtracts the present coordinates of the reticle stage from the target coordinates obtained by multiplying the coordinates (vectors) of the four axes of the wafer stage by a transformation matrix containing as elements functions of the relative rotational angle of the reticle and the wafer and the like to obtain differencesΔRX,ΔRL andΔRR. A reticle stage control system 17 corrects the position and rotational angle of the reticle stage according to these differences.
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