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In this letter, the strain field below uncapped Ge islands of a different shape on a Si(001) substrate is estimated by molecular dynamics simulations at a realistic scale. Comparison to the Fourier transform maps of transmission electron micrographs, recently reported in literature, shows a very good agreement. We point out that the complex deformation in silicon, just below the edges of the Ge islands, is far from being uniaxial. The stress distribution generated by such a strain determines the range of interdot repulsion. (C) 2002 American Institute of Physics.

We perform molecular dynamics simulations to obtain the stress and strain distributions for Ge pyramids with {105} facets on Si(001). We show that the strain induced in the substrate is large and increasing with the pyramid size: up to 0.7% for the 22 nm in base, and corresponds to substrate bending below the pyramid, (C) 2002 Elsevier Science B.V. All rights reserved.

The total energy of equilibrated pyramids layer by layer films and flat prepyramids in the epitaxial growth of Ge on Si (001) was investigated. Molecular dynamics (MD) simulations were applied to equilibrate the samples at atomic scale by the efficient code. It was shown that pyramids are more stable than Frank-van der Merwe (FM) films due to the partial strain relief.