A method and apparatus for creating a phase shifting mask and a structure mask for shrinking integrated circuit designs. One embodiment of the invention includes using a two mask process. The first mask is a phase shift mask and the second mask is a single phase structure mask. The phase shift mask primarily defines regions requiring phase shifting. The single phase structure mask primarily defines regions not requiring phase shifting. The single phase structure mask also prevents the erasure of the phase shifting regions and prevents the creation of undesirable artifact regions that would otherwise be created by the phase shift mask. Both masks are derived from a set of masks used in a larger minimum dimension process technology.