Direct imaging of boron segregation to extended defects in silicon

Abstract

Silicon was implanted with a high boron dose (5×1015 at. cm−2) at 30 keV and further annealed at 950 °C for 30 s. The sample was analyzed using transmission electron microscopy (TEM) and atom probe tomography (APT). TEM images revealed the presence of a high density of dislocation loops (∼1011/cm−2) distributed around the projected range of implanted atoms. APT reconstructions showed local enrichment of boron in the form of loops that were interpreted as Cottrell atmosphere. Boron enriched rods, interpreted as the {113} defects, were also observed. Segregation energies of boron atoms to these defects were estimated to be ∼0.35 eV.