ALIGNER AND ALIGNMENT METHOD

摘要

PROBLEM TO BE SOLVED: To provide an aligner and an alignment method which can achieve higher-precision alignment by compensating the measurement precision of a base line quantity as an aligner equipped with an off-axis type alignment system and its alignment method. SOLUTION: By the alignment method of the aligner which indirectly positions a reticle and a wafer by using a reference mark fixed on a wafer stage, the base line quantity showing the relative position relation between the reticle and wafer is measured and the measured value of the base line quantity is used to predict a base line quantity for next exposure processing, thereby positioning the reticle and wafer according to the predicted value of the base line quantity.