Photomask used for projection exposure with phase shifted auxiliary pattern

摘要

A photomask used for a projection exposure equipment comprises a transparent substrate and a light intercepting film provided on the transparent substrate. The transparent substrate comprises a main pattern region and an auxiliary pattern region provided in a periphery of the main pattern region. The auxiliary pattern region is etched to a depth at which a phase difference arises between light transmitted through the main pattern and light transmitted through the auxiliary pattern. The phase difference is of substantially an integral number of times as large as 360 degrees, wherein the integral number is one selected from the group consisting of integral numbers of one or more and integral numbers of minus one or less. The light intercepting film comprises openings on the main pattern region and the auxiliary pattern region.