Surface passivation of In0.53Ga0.47As ridge quantum wires using silicon interface control layers

Abstract

Surface state effects in In0.53Ga0.47As one-dimensional quantum wires and the effectiveness of the Si interface control layer (Si ICL)-based passivation technique are investigated using photoluminescence (PL) as the probe. Scanning electron microscope and x-ray photoelectron spectroscopy measurements were made to characterize the structure and the interface properties. The In0.53Ga0.47As quantum wires embedded in In0.52Al0.48As barrier material were fabricated by selective molecular beam epitaxy growth on patterned InP substrates. Unpassivated near-surface quantum wires showed an exponential decrease of PL intensity with reduction of surface-to-well distance, tws, similarly to the near-surface quantum wells. By applying the Si ICL-based passivation, a nearly complete recovery of PL intensity was achieved with an observed maximum recovery factor of 250 for the InGaAs quantum wire directly passivated with SiO2/Si ICL (tws=0). The mechanism for the PL recovery is explained in terms of suppression of surface states by passivation.