We have studied the step bunching properties of Si and SiGe layers on vicin
al Si(113) substrates and the self-organized formation and spatial correlat
ion of SiGe wire and island structures induced by such surface steps. The p
arameters for MBE growth have been varied systematically in order to invest
igate the self-assembling and self-ordering mechanisms appearing in growth
of strained SiGe layers on vicinal surfaces. The nanostructures are analyze
d by atomic force microscopy (AFM), transmission electron microscopy (TEM)
and micro Raman spectroscopy. Si(113) substrates have a low surface energy
which is comparable to Si(001) but show a much stronger tendency for bunchi
ng of steps on vicinal surfaces. The Si(113) surface reveals step bunches w
hich are mainly multiples of a 4-atomic step unit. Periodic arrays of SiGe
wires form by strain-mediated self-organization during deposition of a SiGe
/Si multilayer. The correlation of wires in different layers is inclined wi
th respect to the growth direction. This is well described by a model calcu
lation assuming the Si surface steps to locate at the maxima of local strai
n. Ge islands nucleate preferentially at the step edges of vicinal Si(113)
substrates and form ordered rows of islands. No Ge islands but wire-like Ge
accumulations are observed at the step edges of the step bunched SiGe/Si m
ultilayer buffers. (C) 2000 Elsevier Science S.A. All rights reserved.