A method for forming a semiconductor device includes performing a first optimization of a first edge location of a feature fragment, wherein the first optimization has a first speed per fragment, and performing a second optimization of a second edge location of the feature fragment, wherein the second optimization has a second speed per fragment that is slower than the first speed per fragment. Next, a result of the second optimization is used to form a reticle pattern; and a layer on a semiconductor wafer is patterned using the reticle pattern.