Ultra-low energy boron implants in crystalline silicon: Atomic transport properties and electrical activation

We investigated the atomic transport properties and electrical activation of boron in crystalline epitaxial silicon after ultra-low energy ion implantation (0.25-1 keV) and rapid thermal annealing (750-1100 degrees C). A wide range of implant doses was investigated (3x10(12)-1x10(15)/cm(2)). A fast Transient Enhanced Diffusion (TED) pulse is observed involving the tail of the implanted Boron, the profile displacement being dependent on the implant dose. The excess of interstitials able to promote enhanced diffusion of implanted boron occurs, provided the implant dose is high enough to generate a significant total number of point defects. The Boron diffusion following the fast initial TED pulse can be described by the equilibrium diffusion equations.