Patent ID: 7332250

Claim:
A photomask comprising, on a transparent substrate: a semi-shielding portion having a transmitting property against exposing light; a transparent portion surrounded with said semi-shielding portion and having a transmitting property against the exposing light; and an auxiliary pattern surrounded with said semi-shielding portion and provided around said transparent portion, wherein part of said semi-shielding portion is interposed between said transparent portion and said auxiliary pattern, said transparent portion is smaller than a rectangle with a side of (0.8×λ×M)/NA, said auxiliary pattern is a rectangular pattern and has a center line thereof in a position away from the center of said transparent portion by a distance not less than (0.3×λ×M)/NA and not more than (0.5×λ×M)/NA, said semi-shielding portion and said transparent portion transmit the exposing light in an identical phase with respect to each other, said auxiliary pattern transmits the exposing light in an opposite phase with respect to said semi-shielding portion and said transparent portion and is not transferred through exposure, and λ indicates a wavelength of the exposing light, and M and NA respectively indicate magnification and numerical aperture of a reduction projection optical system of a projection aligner.