SI SIGE QUANTUM-WELLS GROWN ON VICINAL SI(001) SUBSTRATES - MORPHOLOGY, DISLOCATION DYNAMICS, AND TRANSPORT-PROPERTIES/

graded, strain relaxed Si0.72Ge0.28 buffers were grown on vicinal Si(0 01) substrates by gas source molecular beam epitaxy. Misfit dislocatio ns are shown to run along intersections of the {111}glide planes with the (11n) interface. X-ray diffraction studies demonstrate a relative tilt of the epilayer to the substrate in a direction which depends on the interplay between substrate orientation related preferential dislo cation nucleation rates and surface contamination induced heterogeneou s nucleation. Atomic force microscopy (AFM) images reveal an anisotrop y in surface roughness on the mu m scale related to reduced growth rat es on vicinal surfaces. Transport properties at 0.4 K in two dimension al electron gases grown on these relaxed SiGe buffers show anisotropic scattering times similar to interface roughness scattering which can be correlated to terrace configurations in the nm range determined by AFM. (C) 1998 American Institute of Physics.