| 摘要 |
PROBLEM TO BE SOLVED: To provide an aligner which always keeps the lens surface clean, thereby preventing the quality and yield of semiconductor devices from lowering by an abnormal pattern or the like. SOLUTION: Provided between a reticle stage 4 and a lens barrel 5 is a lens protective shutter 11, which comprises two column cylinders 12a and 12b and a film 13 having approximately the same width as the height of the cylinders 12a and 12b. The column cylinders 12a and 12b are arranged in parallel, in such a way that their height direction becomes horizontal to the horizontal plane, and the distance between the top sides becomes equal to the distance between the bottom sides. A reticle 3 is generally held between the columns 12a and 12b with a film 13 tightly stretched, horizontal to the horizontal plane with tension, and the film 13 has such an elasticity as to be able to absorb the shock even when the reticle 3 falls on the film. However, at exposing of a wafer 6, the film 13 is taken up around the column 12a so as not to shield the optical path.
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