A structure and method are provided for correcting the optical proximity
effects on a tri-tone attenuated phase-shifting mask. An attenuated rim,
formed by an opaque region and an attenuated phase-shifting region, can
be kept at a predetermined width across the mask or for certain types of
structures. Typically, the attenuated rim is made as large as possible to
maximize the effect of the attenuated phase-shifting region while still
preventing the printing of larger portions of the attenuated
phase-shifting region during the development process.