Stochastic EUV Resist Model

The stochastic effects in photoresist patterning is of great concern in the implementation of EUV lithography. The stochastic nature of EUV chemically amplified resist requires new modeling approaches rather than the continuous model used in DUV. In this paper, a stochastic model based on Gillespie algorithm is introduced, which subdivides the resist volume into many rectangular small cells and simulates the reaction-diffusion behavior of molecules in a cell volume according to carefully calculated probability. In addition, we further explore the influence of the cell size on the stochastic model. There is an optimal cell size in consideration of precision and running time. When cell size is sufficiently large, the results will approximate to the continuous model.