1. A method of phase shifting photolithography, comprising: identifying a pattern for a layer to be formed using photolithographic masking, the pattern including at least a first feature having a first edge; and laying out phase shift regions for the identified pattern to produce a phase shift mask, the phase shift mask having a first set of phase shift regions having a first phase, and a second set of phase shift regions having a second phase, said first set of phase shift regions and said second set of phase shift regions assisting definition of only a portion of the first feature, the portion of the first feature including only the first edge of the first feature.