Patent ID: 7060395

Claim:
A photomask comprising a mask pattern having light-shielding properties with respect to exposure light provided on a transparent substrate having light-transmitting properties with respect to the exposure light, wherein the mask pattern includes a phase shifter that generates a phase difference of (150+360×n) degrees or more and (210+360×n) degrees or less, where n=an integer, with respect to the exposure light between the phase shifter and a light-transmitting portion in which the mask pattern is not formed on the transparent substrate, and a first light intensity generated in a center of a light-shielded image formation region corresponding to the mask pattern on an exposed material by the exposure light transmitted through the phase shifter is not more than four times a second light intensity generated in the center of the light-shielded image formation region by the exposure light that is transmitted through a periphery of the mask pattern on the transparent substrate and goes into a back side of the mask pattern.