Arsenic-flux dependence of surface morphology in InAs homoepitaxy

Surface morphology in molecular-beam epitaxy of InAs(001), (111)A, and (111)B has been studied using scanning tunneling microscopy. The surface morphologies of InAs strongly depend on substrate temperature, substrate orientation, and As/In flux ratio. The size and density of two-dimensional InAs islands on the (001) surface decreases and increases, respectively, as the As/In flux ratio is increased. On the other hand, island size (density) is increased (decreased) with the increase in As flux on (111)A and (111)B surfaces. Surface reconstructions on growing surfaces strongly affect the diffusion and incorporation kinetics of In atoms, thereby resulting in the observed surface morphologies.