Molecular Beam Epitaxy Growth of Atomically Flat GaAs(111)A by As2

We analyzed the growth dynamics during the heteroepitaxy on a GaAs(111)A surface under an As2 flux. The growth is significantly influenced by the Ehrlich-Schwöbel effect and the presence of large multistep islands, which are prominent at high adatom diffusion lengths and high growth rates. We identified the optimal parameters for producing flat GaAs(111)A epilayers with roughness below 0.2 nm. Achieving this requires a growth temperature of 520 °C and a growth rate of approximately 0.5 μm/h, which ensures efficient epilayer production without sacrificing crystal quality or surface flatness. The optimal V/III ratio is compatible with the standard molecular beam epitaxy processes making these findings easily applicable within existing fabrication environments.