Influence of growth temperature on Be incorporation in molecular beam epitaxy GaAs epilayers

Abstract

Photoluminescence investigation of several Be-doped molecular beam epitaxy GaAs epilayers (including post-epi-growth-annealed layers) revealed the presence of nonradiative recombination centers having the following properties. In low-temperature (550 °C)-grown layers their concentration is found to increase with Be acceptor concentration, while high-temperature (640 °C)-grown layers exhibited only a low concentration of these centers. Transmission electron microscope measurements on these layers showed the presence of extrinsic stacking faults involving interstitial atoms. Since this stacking faults density is also found to increase with doping level, we tentatively conclude that Be interstitial atoms are most likely participating in the formation of nonradiative centers.