Patent ID: 7147975

Claim:
A photomask comprising: a mask pattern formed on a transparent substrate; and a transparent portion of said transparent substrate where said mask pattern is not formed, wherein said 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, said main pattern is composed of a first semi-shielding portion that has first transmittance for partially transmitting said exposing light and transmits said exposing light in an identical phase with respect to said transparent portion, and a phase shifter that transmits said exposing light in an opposite phase with respect to said transparent portion, said auxiliary pattern is made from a second semi-shielding portion that has second transmittance for partially transmitting said exposing light and transmits said exposing light in the identical phase with respect to said transparent portion, and a pattern width of said auxiliary pattern is smaller than that of said main pattern.