INDIUM DESORPTION DURING MBE GROWTH OF STRAINED INGAAS LAYERS

We have investigated the In desorption during growth of pseudomorphic InGaAs/GaAs SQWs at various substrate temperatures (500-700-degrees-C) and In contents (5-45%) by photoluminescence and transmission electron microscopy. We present data about temperature dependent growth rates at different In contents. The evaluation of these data shows a strain dependent activation energy for In desorption, which at the low strain limit approaches that of unstrained relaxed InGaAs layers. Our results are in agreement with published data of growth investigations of InAs on GaAs. TEM images of highly strained InGaAs layers show a temperature range, where three-dimensional growth dominates, even for thicknesses far below the critical thickness.