Initial growth behavior of GaAs on ZnSe in MOVPE

We have used atomic force microscopy to investigate the initial stages of the growth of GaAs on ZnSe by metalorganic vapor phase epitaxy. Underlying ZnSe with an atomically flat surface is achieved by growth at 450°C and post-growth annealing at the same temperature. The growth modes of GaAs on the ZnSe surface strongly depend on growth temperatures. The growth carried out at 450°C is 2-dimensional, while that at 550°C is highly 3-dimensional (3D), where the 3D islands are elongated in the 110] direction. The growth behavior, unlike homoepitaxy, is well interpreted in terms of low sticking coefficient and anisotropic lateral growth rate in the heterovalent heteroepitaxy.