Strained layer instabilities on vicinal surfaces:: Ge0.8Si0.2 epitaxy on laser textured Si(001)

Laser textured substrates enable a combinatorial study of strained layer growth morphology as a function of substrate miscut. Si(001) substrates with miscut theta<15degrees off (001) are produced by texturing with nanosecond laser pulses. Ge0.8Si0.2 growth rates are varied over a wide range, 1.7-90 monolayers per minute, at a fixed substrate temperature of 600 degreesC. Film morphologies at all growth rates show strong dependence on the local miscut theta within the dimpled regions of the substrate: the results demonstrate the importance of anisotropy in surface stiffness for the formation of epitaxial nanostructures. The length scales of all structures display a similar trend of decreasing size with increasing growth rate due to the suppression of coarsening at high growth rates. (C) 2004 American Institute of Physics.