Simulation of dopant diffusion and activation during flash lamp annealing

Abstract

A set of advanced models implemented into the simulator Sentaurus Process was applied to simulate ultra shallow junction formation by flash lamp annealing (FLA). The full path transient enhanced diffusion model includes equations for small interstitial clusters (I 2, I 3, I 4), {3 1 1} defects and dislocation loops. A dopant-point defect clustering model is used for dopant activation simulation. Several cluster types are considered: B 2, B 2I, B 2I 2, B 3I, B 3I 2, B 3I 3 for boron and As 2, As 2V, As 3, As 3V, As 4, As 4V for arsenic. Different point defect and dopant-point defect pair charge states are taken into account to obtain accurate results in the high doping level region. The flux expressions in the three-phase segregation model include a dependence on the doping level and point defect supersaturation. The FLA process was performed at various peak temperatures in a Mattson Millios™ fRTP™ system. The measured wafer temperature as a function of time allowed us to simulate the transient processes with a high accuracy. A good agreement between secondary ion mass spectroscopy (SIMS) and simulated profiles was achieved. The sheet resistance dependence on the FLA peak temperature was reproduced successfully.