MOLECULAR-BEAM EPITAXIAL-GROWTH OF ZNSE ON GAAS SUBSTRATES - INFLUENCE OF PRECURSORS ON INTERFACE QUALITY

The initial growth of thin ZnSe layers, grown on GaAs(0 0 1) using mol ecular beam epitaxy (MBE), has been studied using real-time reflection high-energy electron diffraction (RHEED), as well as X-ray double-cry stal rocking curves (DCRC), reflectivity difference spectroscopy (RDS) and transmission electron microscopy (TEM). A noticeable difference i n interface quality and growth was observed depending upon the initial precursor. Exposure to Se flux before growth led initially to three-d imensional growth, whereas exposure to Zn flux or no precursor led imm ediately to two-dimensional growth. X-ray DCRC and RDS confirmed that the overall sample quality was better with two-dimensional growth, and TEM observations were consistent with previous studies which have sho wn that initial three-dimensional growth is related to the formation o f Ga2Se3 at the interface, leading to high densities of stacking fault s and edge dislocations.