Surface morphology in InAs/GaAs(111)A heteroepitaxy: Experimental measurements and computer simulations

The surface morphology of InAs films grown on GaAs(111)A has been studied by scanning tunneling microscopy. The vertical surface displacement on the InAs films has been found to depend on the underlying GaAs buffer layer thickness: specifically, thin GaAs layers are observed to behave mechanically similar to compliant substrates. Atomistic simulations within a valence force field model have been used to compare quantitatively how the InAs surface morphology depends on film thickness and the underlying GaAs layer thickness. The experimental and theoretical results are in excellent agreement over a range of film thicknesses where the misfit dislocation network at the semicoherent InAs/GaAs interface is fully developed.