STRUCTURAL ORDERING IN INGAAS GAAS SUPERLATTICES/

Various x-ray techniques have been applied to a study of semiconductor superlattices consisting of 100-period of InxGa1-xAs (15 Angstrom)/Ga As (100 Angstrom) grown on GaAs (100) substrates by molecular beam epi taxy. Structural parameters pertaining to the morphology of interfaces and thickness variations were obtained. The interfaces in these super lattices are found to be highly correlated, and the layers all show a high degree of crystallinity. Splittings in the x-ray reflectivity and diffraction patterns in one of the samples provide clear evidence for pronounced thickness modulation, and direct comparison of the diffrac tion satellite peaks with results of high resolution transmission elec tron microscopy indicates that there exists a lateral structural order ing in the [110] direction during epitaxial growth. (C) 1996 American Institute of Physics.