Secondary implantation of Sb into Si molecular beam epitaxy layers

Abstract

We report on the influence of low-energy Si+ ions on the incorporation of Sb adatoms existing on growing (100) Si molecular beam epitaxy layers. At a growth temperature of 650 °C employed for these experiments an increase of incorporation of about three orders of magnitude compared to the spontaneous incorporation is obtained at ion flux densities of typically 1012 cm−2 s−1. Dopant activation coefficients of almost unity are established up to 1019 cm−3. The number of incorporated adatoms is found to increase proportionally with preadjusted adatom density as well as with Si+ ion dose. At an ion energy of 500 eV the constant of proportionality is estimated to be σI =(5±2)×10−16 cm2.