| 摘要 |
Two lithographic substrate stages are used in a single lithographic system. While a substrate on one stage is being exposed, a second substrate is being loaded, unloaded, or aligned on a second stage. After exposure, the first stage is unloaded, reloaded, and the newly-loaded substrate is aligned, while the second substrate on the second stage is being exposed. The two stages are thus used alternately in different steps of the process. One of the steps is being performed on one stage while a different step is being performed on the other stage. The substrates on both stages are, therefore, being acted upon simultaneously. The two stages are carried on a single linear motor platen, and moved about the platen by use of linear motors. The two stages alternately both move in clockwise directions about the platen, or both move in counterclockwise directions. When both move in clockwise directions, the first stage is moving to the exposure position, and the second stage is moving to the unload/load/align station. When they both move in counterclockwise directions, the second stage is moving to the exposure position and the first stage is moving to the unload/load/align station.
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