Metrology apparatus for mask used with lithographic projection apparatus and used for manufacturing integrated circuits has mask holder which supports mask along horizontal edge of mask with uniformly distributed force against gravity

摘要

The mask metrology apparatus (1) has a mask holder (2) for holding a mask (3) having an object plane with marks (4); a mask positioning device (5) for positioning the mask holder in a predetermined position; and measurement optics (6) for measuring the position of the marks of the mask held by the mask holder. The mask holder holds the mask with the object plane substantially parallel to the direction of gravity and supports the mask along a horizontal edge of the mask with a uniformly distributed force against gravity. An independent claim is also included for a measuring method for a mask.