An atomistic kinetic Monte Carlo model for boron diffusion in amorphous silicon was presented. Boron diffusion was assumed to be indirect, mediated by dangling bonds present in a-Si. The model showed a transient character due to a-Si relaxation modelled by dangling bond annihilation. In addition, B produced clusters at higher concentrations, leading to an immobile B part. The model, when calibrated, was successfully applied to experiments of thermal anneals of amorphized B marker layers and B implantation into pre-amorphized Si. In addition, the contribution of B diffusion in a-Si in ultra-shallow junction formation of advanced technologies was studied. The model was also used to demonstrate how the contribution to diffusion of B in a-Si in current and future technologies could be higher than that in c-Si.

Indirect Boron Diffusion in Amorphous Silicon Modeled by Kinetic Monte Carlo. I.Martin-Bragado, N.Zographos: Solid-State Electronics, 2011, 55[1], 25-8