Size effects on the electrical activation of low-energy implanted B in Si

The phenomena related to the electrical activation of low energy implanted B $(3keV,2×1014B∕cm2)$ in laterally submicron confined Si regions were studied by high resolution quantitative scanning capacitance microscopy (SCM). The B diffusion and its precipitation into electrically inactive B–Si interstitial clusters (BICs) were studied by varying the implant window size from $3.2to0.38μm$ and annealing at $800°C$ from $12to200min$ in $N2$ ambient. In particular, the electrically active B fraction is followed by calculating the carrier concentration profile from SCM data with increasing the annealing time. Both the B reactivation and diffusion exhibit a strong dependence on the window width. The higher electrically active B fraction is always found in the narrowest window, which also first recovers the almost complete electrical activation. The B diffusivity enhancement for the $3.2μm$ window size is more than one order of magnitude higher than for the $0.38μm$ window.