Method of manufacturing photomask

摘要

A method of manufacturing a photomask includes determining an average value of dimensions of a pattern in a photomask. determining an in-plane uniformity of the dimensions, determining an exposure latitude on the basis of the average value and the in-plane uniformity. The exposure latitude depends on dimensional accuracy of the pattern. Judging if the photomask is defective or non-defective is made on the basis of whether or not the exposure latitude falls within a prescribed exposure latitude