摘要 |
Disclosed is a projection optical system for projecting a pattern of a mask placed on an object plane, onto a substrate placed on an image plane. The projection optical system is arranged so that an intermediate image of the pattern formed on the mask, is formed between a third reflection surface and a fourth reflection surface. In accordance with a particular shape of the third reflection surface or with particular disposition, high-precision projection is ensured without enlargement in size of the whole system.
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