Patent ID: 7632613

Claim:
A Levenson type phase shift mask comprising light shielding portions and openings formed on a transparent substrate, the transparent substrate at the openings being partially dug in or a light shielding film being partially disposed on the transparent substrate at the openings to form shifter openings and non-shifter openings, the shifter openings and the non-shifter openings repetitively existing in the mask, the shifter openings inverting a phase of transmitted light, the Levenson type phase shift mask having: a first light shielding portions pattern disposed between the adjacent shifter openings of the same kind, and a second light shielding portions pattern disposed between the shifter opening and the non-shifter opening; the first light shielding portions pattern being subjected to bias correction which expands the first light shielding portions pattern to both sides thereof in a predetermined amount with respect to a predetermined design line width set by a design of the mask, and the first light shielding portions pattern having no undercut on the side of the shifter opening; and the second light shielding portions pattern having an undercut on the side of the shifter opening.