LATTICE LOCATION OF ERBIUM IMPLANTED INTO GAAS

The lattice location or erbium atoms implanted into GaAs with energy of 150 keV to a dose of 10(15) cm-2 at 250-degrees-C has been studied using Rutherford backscattering and channeling spectroscopy. It is shown that in as-implanted samples the Er atoms are displaced from their substitutional positions towards the middle of the <1 1 0> channel. The implanted Er atoms approach substitutional locations as a result of rapid thermal annealing within temperature range of 700-1000-degrees-C. After 30 s annealing at 1000-degrees-C, at least 90% or Er atoms occupy lattice positions. However, the optical activity of the erbium atoms disappears entirely after they have been located on substitutional lattice sites.