Patent ID: 7803502

Claim:
A photomask comprising: a mask substrate to be irradiated with irradiation light; a first phase shifter comprising three or more first type phase shift elements, wherein the three or more first type phase shift elements are arranged on the mask substrate with a first pitch not larger than eight times a wavelength of the irradiation light, and wherein the first phase shifter has a transmittance of not more than 5% for the irradiation light and phase-shifts the irradiation light by 180°; and a second phase shifter comprising three or more second type phase shift elements, wherein the three or more second type phase shift elements are arranged on the mask substrate with a second pitch larger than eight times the wavelength of the irradiation light, and wherein the second phase shifter has a transmittance of not more than 5%, and phase-shifts the irradiation light by 180°.