Investigation of the epitaxial growth of InxGa1−xAs on GaAs(001) and extension of two-dimensional–three-dimensional growth mode transition

Abstract

The growth of highly strained InxGa1−xAs (x≳0.25) epilayer on GaAs (001) undergoes a two-dimensional–three-dimensional (2D-3D) growth mode transition beyond a critical thickness which depends on the strain. We show that the growth mode is controlled by the island-edge diffusion carrier which originates from elastic energy relaxation at the edge of 2D island. The 2D-3D growth mode transition depends upon whether or not a new layer nucleates on top of the island of 2 ML height before coalescence. The In atoms on the surface arising from surface segregation affect the island-edge diffusion barrier and nucleation, leading to a 3D growth mode at the critical thickness. The experimental investigation is explained satisfactorily.