A method for determining mask patterns to be used on photo-masks in a multiple-exposure photolithographic process is described. During the method, an initial mask pattern, which is intended for use in a single-exposure photolithographic process, and a target pattern that is to be printed are used to determine a first mask pattern and a second mask pattern, which are intended for use in the multiple-exposure photolithographic process. In particular, the first mask pattern includes a first feature and the second mask pattern includes a second feature, and the first feature and the second feature overlap an intersection between features in the initial mask pattern. Moreover, the first mask pattern and the second mask pattern have at least one decreased spatial frequency relative to the initial mask pattern along at least one direction in the initial mask pattern.