PHOTOMASK PATTERN INSPECTION

摘要

For inspecting the arrangement of unit patterns (2A to 2F; 41) on a photomask, the unit patterns being intended to have having the same shape and size and to be printed repeatedly with equal intervals on the photomask; shear-detecting-patterns (3a to 3c) are provided on each unit pattern so that pairs of adjacent shear-detecting patterns belonging to adjacent unit patterns form combined-patterns (51 to 53, 61 go 63, 71 to 73;81 to 86, 91 to 96). In a group of such combined-patterns all the combined-patterns should have the same shape and size. One combined-pattern of the group is designated a standard-pattern and comparison is effected between the standard-pattern and another combined pattern of the group. The comparison yields a difference amount from which it is determined whether the combined-pattern arrangement in the group is correct.