Suppression of phosphorus diffusion using cluster Carbon co-implantation

Phosphorus transient enhanced diffusion (TED) is caused by interstitial diffusion mechanism. It is important for the efficient suppression of phosphorus diffusion that some carbons could be located on lattice point in the initial stage of re-growth during annealing and trap interstitial Silicon. Carbon co-implantation after Germanium, pre-amorphization implantation (PAI) is applied for the applications of n+/p junction formation and the effects of Carbon co-implantation are reported. In our experiments it is shown that suppression of Phosphorus diffusion could be achieved with conventional rapid thermal annealing (RTA) by using cluster Carbon (C₁₆H_x⁺, C₇H_x⁺) co-implantation for the self-amorphization. Our experimental data suggests that cluster carbon co-implantation enable to suppress phosphorus diffusion without germanium pre-amorphous implantation. In this paper the characteristics of cluster Carbon co-implantation after RTA are introduced from experimental results which were obtained by secondary ion mass spectroscopy (SIMS) measurement, transmission electron microscopy (TEM) and sheet-resistance measurement.