An investigation was made of defects, in ZnSe epitaxial layers, which were introduced during the initial stages of gas-source molecular beam epitaxy onto (100) GaAs epitaxial layers. The ZnSe layers were grown onto GaAs surfaces with a (4 x 8) Ga-stabilized reconstruction. Streaky reflection high-energy electron diffraction patterns were observed throughout 100nm of growth. The defects in the ZnSe layers were studied by means of plan-view and cross-sectional transmission electron microscopic observations. In the gas-source molecular beam epitaxial layers, stacking faults with a density that was of the order of 108/cm2 formed in pairs. All of the stacking faults originated from the interface between the ZnSe and the GaAs. A comparison of the results, for ZnSe layers that had been grown by solid-source molecular beam epitaxy, showed that the stacking faults which originated from the interface seemed to be characteristic defects in ZnSe layers which had been grown by gas-source molecular beam epitaxy. This was attributed to differences in the Se species that were involved in the gas-source molecular beam epitaxy and molecular beam epitaxy techniques.

Y.Endoh, J.Tanimura, M.Imaizumi, M.Suita, K.Ohtsuka, T.Isu, M.Nunoshita: Journal of Crystal Growth, 1995, 154[1-2], 41-6