Monte Carlo impurity diffusion simulation considering charged species for low thermal budget sub-50 nm CMOS process modeling

A Monte Carlo dopant diffusion simulation program has been developed which includes charged species, Fermi-level effects on drift-diffusion and clustering reactions. An algorithm that determines variable time steps was improved to account for all the Fermi-level dependent quantities, such as different charge states of point-defects, pairs and complexes, and different diffusivities/reaction rates for them. Simulations of two extreme low thermal budget processes, i.e. spike-anneal (>1050/spl deg/C) and low temperature (<550/spl deg/C and long time) anneal for typical sub-50 nm CMOS processes have been demonstrated by using this MC program.