Si/Ge-nanocrystals on SiC(0001)

The growth and structure of Si- and Ge-nanocrystals was investigated using high resolution X-ray diffraction (HRXRD) and atomic force microscopy (AFM) . AFRI-images were used to determine the lateral and vertical dimensions of the nanocrystal. HRXRD measurements show clearly that Si- and Ge-nanocryst als grow on 6H-SiC(0001) preferentially in two different orientations - [11 1] and [110] - with respect to the surface normal. The growth of Ge-nanocry stals on Si-rich 6H-SiC(0001) surfaces leads to the formation of Si/Ge-allo y nanocrystals. Both types of nanocrystals grow coherently with respect to the substrate. Hence, due to the respective lattice mismatch, the degree of coherence was found to be much better for Si-nanocrystals. (C) 2000 Elsevi er Science B.V. All rights reserved.