| 摘要 |
An exposure system and exposure method that can maintain high mask alignment accuracy and throughput in a process requiring frequent mask changes. In the exposure process of a batch of wafers, the patterns on two reticles are projected onto one region of the wafer to superpose them one on the other. If both reticles are used for the first time, the positions of all alignment marks on the reticle are measured (precise positioning). Based on the measurement result, the reticles are positioned (S132, S135). If the reticles have been used before, the positions of only one set of alignment marks are measured to correct the results of the precise positioning. Based on the measurement result, the reticles are positioned (S133, S136).
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