Observation of quasiperiodic faceting both on MOCVD-grown and on gas-etched surfaces of vicinal (1 1 0)GaAs substrates

Abstract Surface morphology has been studied by means of Nomarski and atomic-force microscopy regarding grown or etched surfaces of vicinal (1 1 0)GaAs substrates. The substrates used were misoriented by 2° or 6° towards [ 0 0 1 ], [ 0 0 1 ], [ 1 1 1 ], or [ 1 1 1 ]. The same reactor was used both for metal-organic chemical vapor deposition (MOCVD) growth and for HCl gas etching. The surface showed a variety of morphology, depending on the misorientation and on whether they are grown or etched. Among them, quasiperiodic macrosteps of 15–70 nm in height were observed on the grown surfaces as well as on the etched surfaces when the misorientation was towards [ 0 0 1 ]. The edge lines of the macrosteps showed excellent straightness on the grown surface when the substrate was misoriented towards [ 0 0 1 ] by 6°.