MULTIATOMIC STEP FORMATION MECHANISM OF METALORGANIC VAPOR-PHASE EPITAXIAL GROWN GAAS VICINAL SURFACES AND ITS APPLICATION TO QUANTUM-WELL WIRES

The multiatomic steps formed on GaAs vicinal surfaces by metalorganic vapor phase epitaxy (MOVPE) are by atomic force microscopy (AFM). An A FM image of an epitaxially grown GaAs surface showed coherent multiato mic steps with extremely straight edges over a wide area. The average height and spacing of the multiatomic steps are 1.2-8 and 30-110 nm, r espectively. These terrace widths change with the growth conditions. N arrower terrace widths are obtained at higher growth rates, and under higher AsH3 partial pressures and higher impurity doping conditions. T he results suggest that the migration distance of a Ga atom on the ter race and the sticking coefficient at the step sites depend on these gr owth conditions. Using multiatomic steps, GaAs/AlGaAs quantum well wir es (QWWs) were grown on a GaAs vicinal surface. Cross-sectional transm ission electron microscopy and photoluminescence show the successful f abrication of QWWs.