1. A method for converting an integrated circuit design to a phase-shift compliant mask design, the method comprising the steps of: (a) locating features of the integrated circuit that violate predetermined design criteria; (b) modifying the features located in Step (a) based on a predetermined cost constraint; (c) determining if the Step (b) corrected all violations determined in the Step (a), changing the cost constraint to a further cost constraint if violations still exist and terminating the conversion if the violations are corrected; and (d) repeating steps (b) and (c).