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 (3 keV,2× 1014 B 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 3.2 to 0.38 μm and annealing at 800°C from 12 to 200 min 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 3.2 μm window size is more than one order of magnitude higher than for the 0.38 μm window. © 2006 American Vacuum Society.