Theoretical investigation of implanted dopant diffusion from a silicide layer to the silicon wafer for ultra shallow p-n junction formation

In this work a theoretical model is presented to analyze the technique recently suggested to form shallow p-n junction. According to this technique a silicide acts as a source of a dopant and it is followed by controlled diffusion anneal to accomplish the dopant penetration into a silicon wafer. In our analysis the dependence of the p-n junction depth on process parameters is discussed. The model considers two cases, namely, with and without dopant evaporation. Experimental data for B diffusion from CoSi₂ acting as the source are used to evaluate our theoretical model. The agreement between theoretical and experimental results is satisfactory.