Phase shifting mask, manufacturing method thereof, and exposure method using such a phase shifting mask

Claim 1

An exposure method, comprising the steps of: emitting exposure light from a light source; directing said exposure light to a phase shifting mask; and projecting the exposure light transmitted through said phase shifting mask onto a photoresist placed on a film to be etched for photosensitizing said photoresist, wherein said phase shifting mask includes a substrate including a first light transmitting portion which transmits said exposure light and a second light transmitting portion which is adjacent to said first light transmitting portion and transmits exposure light to have a different phase from that of the exposure light transmitted through said first light transmitting portion, and a semi-light shielding film which is located at an interface between said adjacent first and second light transmitting portions and formed in a part of said first and second light transmitting portions, said first light transmitting portion includes a first transmitting region and a first attenuated transmitting region in which said semi-light shielding film is formed, light intensity of exposure light transmitted through said first transmitting region is greater than that of the exposure light transmitted through said first attenuated transmitting region, said second light transmitting portion includes a second transmitting region and a second attenuated transmitting region in which said semi-light shielding film is formed, light intensity of exposure light transmitted through said second transmitting region is greater than that of the exposure light transmitted through said second attenuated transmitting region, and said semi-light shielding film has transmittance of at least 3% and not more than 30%.