Photomask, pattern formation method using photomask and mask data creation method

摘要

A mask pattern includes a main pattern to be transferred through exposure and an auxiliary pattern that diffracts exposing light and is not transferred through the exposure. The main pattern is made from a shielding portion, a phase shifter or a combination of a semi-shielding portion or a shielding portion and a phase shifter. The auxiliary pattern is made from a shielding portion or a semi-shielding portion. The auxiliary pattern is disposed in a position away from the main pattern by a distance M x (»/(2 x sinÕ)) or M x ((»/(2 x sinÕ)) + (»/(NA + sinÕ))), wherein » indicates a wavelength of the exposing light, M and NA indicate magnification and numerical aperture of a reduction projection optical system of an aligner and Õ indicates an oblique incident angle.