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 b y scanning tunneling microscopy. The vertical surface displacement on the I nAs films has been found to depend on the underlying GaAs buffer layer thic kness: specifically, thin GaAs layers are observed to behave mechanically s imilar to compliant substrates. Atomistic simulations within a valence forc e field model have been used to compare quantitatively how the InAs surface morphology depends on film thickness and the underlying GaAs layer thickne ss. The experimental and theoretical results are in excellent agreement ove r a range of film thicknesses where the misfit dislocation network at the s emicoherent InAs/GaAs interface is fully developed. (C) 1999 American Insti tute of Physics. [S0003-6951(99)00732-9].