Selective incorporation of Si along step edges during delta-doping on MOVPE-grown GaAs (001) vicinal surfaces

We investigated the delta-doping (δ-doping) of Si using SiH₄ on MOVPE-grown GaAs (001) vicinal surfaces to explore the possibility of selective incorporation of Si along atomic steps, and to demonstrate doping quantum wires by the combination of multiatomic steps and wire-like doping. It was found that the doping density on vicinal surfaces was enhanced as the misorientation angle was increased, which suggested the enhanced decomposition of SiH₄ and the selective incorporation of Si at step edges. It was also found that this selective incorporation could be enhanced by annealing the surface prior to the δ-doping, which resulted from the reduced incorporation of Si at the terrace regions. Anisotropic electron transport properties which are expected from the wire-like incorporation along step edges are also discussed.