GaAs(0 0 1) planarization after conventional oxide removal utilising self-governed InAs QD site selection

Native oxide removal on GaAs(0 0 1) wafers under conventional thermal desorption causes severe surface degradation in the form of pitting. Typical surface regeneration requires several hundred nanometres of buffer layer growth. This level of planarization is necessary to fill in the deep pits since Ehrlich–Schwoebel diffusion barriers cause a retardation of layer growth at multiple monolayer step edges. Pits are, however, attractive nucleation sites for quantum dots (QDs), and hence QDs fill the pits via a self-governing phenomenon. In this paper, we show how 1.7 ML of InAs growth on GaAs(0 0 1) immediately after thermal oxide removal aids the healing of the surface and reduces the necessity for thick buffer layer growth.