The effect of boron doping on the thermal behaviour of EOR defects in Silicon

Abstract

In this paper, we report for the first time that the doping level has a drastic effect on the growth and dissolution kinetics of EOR (End-Of-Range) defects upon annealing. TEM (Transmission Electronic Microscopy) observations were performed on B doped Si wafers (from 1.5×10 15 to 10 20 at/cm 3 ) amorphized with a Ge beam at 150 keV and a dose of 2×10 15 ions/cm 2 and annealed at 1000°C. Below 2.10 18 at/cm 3 the loop density and the number of atoms stored in the loops increase with doping. Above this value, the loop density decreases and for 10 20 at/cm 3 the loops have disappeared. This is interpreted in terms of intrinsic/extrinsic mechanisms for Si self-diffusion since at 1000°C, n i is of the order of a few 10 18 at/cm 3 This behaviour is of prime importance to understand the transient enhanced diffusion of boron in the vicimty of EOR defects.