Mesoscopic resist processing simulation in optical lithography

Line-edge roughness (LER) control and minimization are among the critical issues for the further advancements in EUV and optical lithography. For the simulation of LER, discrete and stochastic models are required. This paper presents an improved stochastic exposure simulation model. It is proven that it is not necessar y to take the Poisson distribution of the photon statistics into account. Mesoscopic exposure and post exposure bake models are compared with continuous, deterministic models in terms of obtained CD values, convergence behavior, and required computing time. The results obtained with both methods show a very good agreement.