Patent ID: 7968255

Claim:
A photomask used for photolithography using an ArF excimer laser as an exposing source for immersion exposure by quadrupole-polarized illumination with a high-NA lens, wherein the photomask comprises a mask pattern of a light shielding film or semi-transparent film on a transparent substrate, wherein, given that a thickness of the light shielding film or semi-transparent film is “t” nm, a refractive index is “n”, an extinction factor is “k”, and a bias of a space part of the mask pattern is “d” nm, when “t”, “d”, “n” and “k” are adjusted and the photomask is used for the photolithography, optical image contrast has a value exceeding 0.580, and further wherein the “t”, “d”, “n” and “k” are one set selected from the following ranges: 0<t≦20, −100≦d <−50, 0.5≦n<0.9, and 2.8<k≦3.0; 20<t ≦40, −100≦d<0, 0.5≦n <2.9, and 1.6<k≦3.0; 40<t≦60, −100≦d<0, 0.5≦n≦2.9, and 1.0<k≦3.0; 60<t≦80, −100≦d <−50, 0.5≦n≦2.9, and 0.6<k≦3.0; 80<t≦160, −100≦d<−50, 0.5≦n≦2.9, and 0.4<k ≦3.0; 160<t≦200, −100≦d<−50, 0.5≦n≦2.9, and 0.2<k ≦3.0; 60<t≦120, −50≦d<0, 0.5≦n≦2.9, and 0.4<k≦3.0; 120<t≦160, −50≦d<50, 0.5≦n≦2.9, and 0.2<k≦3.0; 160<t≦200, −50≦d<50, 0.5≦n≦2.9, and 0.0<k≦3.0; 40<t≦60, 0≦d<50, 0.5≦n<1.3, and 2.2<k ≦3.0; 60<t≦80, 0≦d<50, 0.5≦n<2.5, and 0.4<k ≦3.0; 80<t≦120, 0≦d<50, 0.5≦n≦2.9, and 0.4<k≦3.0; 140<t≦160, 50≦d<100, 0.5≦n <0.7, and 2.2<k<2.8; 160<t≦180, 50≦d<100, 0.5≦n<1.5, and 1.2<k<2.8; and 180 <t≦200, 50≦d<100, 0.5≦n<2.1, and 0.0<k<2.8.