P implantation into preamorphized germanium and subsequent annealing: Solid phase epitaxial regrowth, P diffusion, and activation

Abstract

Phosphorus implantation (30 keV, 3×1015 cm−2) into preamorphized Ge and subsequent rapid thermal or flash lamp annealing is investigated. During annealing a significant P diffusion in amorphous Ge is not observed. However, the fast solid phase epitaxial regrowth causes a rapid redistribution of P. After completion of the regrowth and at temperatures above 500 °C, a concentration-dependent diffusion of P in crystalline Ge takes place and leads to considerable loss of P toward the surface. An appreciable influence of implantation defects on the diffusion coefficient of P is not detected. For 60 s rapid thermal annealing at 600 °C and for 20 ms flash lamp annealing at 900 °C, the junction depth and the sheet resistance vary between 140 and 200 nm and between 50 and 100 Ω, respectively, and the maximum electrical activation of P is about 3–7×1019 cm−3.