Patent ID: 6839890

Claim:
A method for forming, on a mask, a mask pattern used for exposure, which mask pattern includes a first pattern that blends plural types of patterns, and a second pattern that is smaller in size than the first pattern, the mask pattern being arranged on the mask so that the first pattern may be resolved and the second pattern is prevented from being resolved, said method comprising the steps of: classifying the first pattern into one of a periodic pattern having at least three elements having two equal intervals in at least one direction among two orthogonal directions, an isolated pair pattern that does not belong to the periodic pattern and includes a pair of elements arranged in at least one direction among the two orthogonal directions, and an isolated element that does not belong to the isolated pair pattern and includes only one element without constituting any pair in any of the two orthogonal directions; arranging the second pattern for the isolated pair pattern; arranging the second pattern for the isolated element; and arranging the second pattern for the periodic pattern.