MBE-growth of InAs/GaAs(0 0 1) quantum dots at low temperatures

We study the strain-induced formation of InAs quantum dots (QDs) on GaAs(0 0 1) at a low growth temperature of 265 °C (LT-mode). The influence of In flux, As4 partial pressure, as well as InAs coverage on the InAs surface morphology are investigated. It is shown that under certain deposition conditions QDs are formed even at the low temperature and that the growth parameters strongly influence the QD shape and density. Measurements of the critical coverage of QD formation as a function of growth temperature and speed are explained by a growth model for strain-induced InAs QD formation. After optimization of the InAs LT-growth parameters, InAs QDs are obtained with morphological properties comparable to those grown in the high-temperature (HT) regime.