A method of generating complementary masks for use in a multiple-exposure lithographic imaging process. The method includes the steps of identifying “horizontal” critical features and “vertical” critical features from a plurality of features forming a layout; identifying interconnection areas which are areas in which one of the horizontal critical features or the vertical critical features contacts another feature of the layout; defining a set of primary parameters on the basis of the proximity of the plurality of features relative to one another; and generating an edge modification plan for each interconnection area based on the primary parameters. A horizontal mask pattern is then generated by compiling the horizontal critical features, a first shield plan for the vertical critical features and the interconnection areas containing a horizontal critical feature modified by the edge modification plan. A vertical mask pattern is then generated by compiling the vertical critical features, a second shield plan for the horizontal critical features and the interconnection areas containing a vertical critical feature modified by the edge modification plan.