Printability Enhancement with Color Balancing for Multiple Patterning Lithography

Due to the delay of Next Generation Lithography technologies, multiple patterning lithography (MPL) is still the major solution for the continuous advance of process nodes. Considering pattern color (density) balancing on multiple masks during layout decomposition is crucial to reduce pattern distortion and lithographic hotspots. While most of previous studies consider global color balancing during layout decomposition, we propose the first work of post-decomposition local color uniformity optimization, which will contribute to better pattern printability. In our flow, a linear programming (LP) formulation is developed to derive a good initial solution, and then a simulated annealing (SA)-based algorithm is proposed to globally search optimal solutions. Finally, a solution refinement procedure is applied based on the FM partitioning heuristic. The proposed flow is suitable for general MPL with an arbitrary number of masks, and we respectively demonstrate its effectiveness on double patterning lithography (DPL) and triple patterning lithography (TPL). The former indicates that our flow can derive near-optimal solutions, and the latter shows about 29 percent improvement over a state-of-the-art color balancing-aware TPL decomposer.