Optimization on illumination source with design of experiments
Helen Hu, Yi Zou, Yunfei Deng · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2010
In advanced photolithography process for manufacturing integrated circuits, the critical pattern sizes that need to be printed on wafer are much smaller than the wavelength. Thus, source optimization (SO) techniques play a critical role in enabling a successful technology node. However, finding an appropriate illumination configuration involves intensive computation simulations. EDA vendors have been developing the pixelated source optimization tools that co-optimize both source and mask for a set of patterns. As an alternative approach, we have introduced design of experiments (DOE) methodology for parameterized source optimization to minimize computation efforts while achieving comparable CDU control for given design patterns. In this paper, we present a Response Surface Methodology (RSM) that simplifies the response function and achieves the optimization goal on multiple responses. Results have shown that the optimal input settings identified by this approach are comparable with the pixelated source optimization results.