Epitaxial growth and surface modeling of ZnO on c-plane Al2O3

The growth of ZnO on c-plane sapphire by molecular beam epitaxy is presented for varying ratios of zinc and oxygen flux. Reflection high energy electron diffraction patterns during epitaxial growth suggest clear differences in the evolution of surface morphology for differing Zn flux. Atomic force microscope images indicate sizable hexagonal features in the surface morphology for Zn-rich material. A stochastic growth model is presented to represent the experimental ZnO surface, where differences in adatom lateral diffusion length are suspected to be the cause of the differing surface morphology. (C) 2004 American Institute of Physics.