The Effects of AsH₃ Preflow Conditions at Low Temperature on the Morphology of GaAs Buffer Layers for GaAs/Si Grown by Metalorganic Chemical Vapor Deposition

In the two-step growth of GaAs on Si, the effects of AsH 3 preflow conditions (preflow time and preflow rate) at a low temperature (450°C) on the morphology of GaAs buffer layers (GaAs islands) have been investigated with scanning electron microscopy. As the preflow time or preflow rate was increased, the islands were aligned parallel to the step edges of the misoriented Si surface, and Si surface coverage was increased. These results indicate that the sufficient AsH 3 preflow to the Si surface at low temperatures forms both multilayer steps on the Si surface for GaAs island nucleation and a stable GaAs/Si interface.