A markedly low stacking-fault density was found in ZnSe epilayers which had been grown directly onto commercial epi-ready GaAs (001) substrates, without a GaAs buffer layer. It was found that the correct pre-growth treatment of epi-ready GaAs (001) substrates, in order to obtain clean surfaces, was essential to 2-dimensional layer-by-layer growth and to the suppression of stacking-fault generation. A clean GaAs (001) surface, which was here characterized by a (4 x 1) reconstruction, was obtained after thermal cleaning followed by Zn pre-exposure. Reflection high-energy electron diffraction intensity oscillations, with more than 50 periods, were observed from the very onset of ZnSe growth on GaAs substrates. The stacking fault densities in such a ZnSe layer were of the order of 105/cm2.

Low Stacking-Fault Density in ZnSe Epilayers Directly Grown on Epi-Ready GaAs Substrates without GaAs Buffer Layers. S.K.Hong, E.Kurtz, J.H.Chang, T.Hanada, M.Oku, T.Yao: Applied Physics Letters, 2001, 78[2], 165-7