Efficient simulation of three-dimensional EUV masks for rigorous source mask optimization and mask induced imaging artifact analysis
In this paper a rigorous three dimensional EUV mask simulation model is presented. The mask near field is simulated with the Waveguide method which is similar to the RCWA approach. Additionally the method is extended by a so called decompositions technique. The mask image is computed by coupling the Waveguide method with a fully vectorial imaging simulation model based on an extended Abbe approach. The basic theory of the models is explained. The optimization and combination of both simulation approaches enables the simulation and analysis of larger EUV mask areas required for the analysis of complex three dimensional EUV mask structures as well as the very fast simulation of standard sized EUV mask areas required in the context of source mask optimizations. Corresponding simulation examp les like a rigorous source mask optimization and a mask induced imaging artifact analysis of a larger mask area demonstrate the capabilities and the performance of the new simulation system.