Reflectivity analysis of ZnS layers grown on GaAs and Si substrates by metal organic vapour-phase epitaxy

Abstract

We have grown high-purity ZnS layers by metal organic vapour-phase epitaxy onto (100) GaAs and (111) Si substrates using triethylamine dimethylzinc. As is usually reported, the morphology and the crystalline quality assessed by the optical Nomarski microscopy and by double X-ray diffraction are similar on both substrates. However, we demonstrate for the first time, using reflectivity experiments along with a theoretical fit, that the crystalline quality of the sample deposited onto Si substrates is much poorer. This observation is interpreted in terms of antiphase defects related to the lack of polarity of the Si substrate.