ABSTRACT
Coherent multiatomic steps on vicinal (001) GaAs surfaces during metalorganic vapor phase epitaxial (MOVPE) growth are investigated by atomic force microscopy (AFM). AFM images show coherent multiatomic steps with extremely straight edges over a several micron scale. The average spacing of multiatomic steps depends on growth temperature, growth rate and AsH3 partial pressure. Similar multiatomic steps also appear on GaAs substrate surfaces after thermal treatment under AsH3/H2 atmosphere at temperatures higher than 700 °C. Furthermore, we fabricate GaAs quantum well wires (QWWs) on these coherent multiatomic steps. Locally thick GaAs, that is, QWWs are formed at corners of multiatomic steps. Photoluminescence spectra of QWWs show energy shift caused by the QWWs formation. These results suggest that self-organized QWWs can be formed uniformly on coherent multiatomic steps.
