Patent ID: 6939649

Claim:
A fabrication method of a semiconductor integrated circuit device, comprising the steps of: preparing a mask having, on a first main surface of a mask substrate, a first light transmitting region, a second light transmitting region disposed at the periphery of the first light transmitting region and permitting inversion of the phase of a light transmitted through the second light transmitting region relative to a light transmitted through the first light transmitting region, and a light shielding region disposed at the periphery of the second light transmitting region; and transferring predetermined patterns to a photoresist film over the main surface of a wafer by projection exposure reduction treatment using the mask, wherein said second light transmitting region has a first film formed over the first main surface of the mask substrate, wherein said light shielding region has a second film formed over the first main surface of the mask substrate via said first film, and wherein at least one of said first film and second film is a resist film.