Mask for correcting optical proximity effect

摘要

A mask corrects for an optical proximity effect (OPE). A dummy pattern having a phase-edge effect is formed on a mask substrate. The phase-edge effect reduces the intensity of light boundary of two transmitting regions from through transmitted light has a phase difference. A pattern can then be formed in a photolithographic process using the phase-edge effect. A difference between "isolated" and "dense" patterns formed on a wafer can be reduced by forming a dummy pattern in a isolated pattern region of the mask and making the diffraction pattern of the isolated pattern the same as that of the dense pattern, thereby improving the total focus margin. Because the intensity of light is reduced at the boundary between a first region in which the phase of the transmitted light is 0� and a second region in which the phase of the transmitted light is 180�, for example, a photoresist layer is not photosensitized.