| 摘要 |
A system and method for exposing a layer of resist on a target such as a semiconductor wafer are provided. An optical system includes a step and repeat projection aligner, and a mask having adjacent complementary pattern segments arranged in an alternating array of columns and rows. The method includes exposing the layer of resist in multiple stages by directing exposure energy through the mask onto the target. During each stage the target can be stepped through unequal stepping distances. A first stepping distance can be a width of a single pattern segment, and a second stepping distance can be a combined width of multiple pattern segments. The unequal stepping distances permit the complementary pattern segments to be initially exposed, and then overlayed on the target using relatively short stepping distance across most of the target.
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