Three mechanisms by which edges induce stress relaxation in GeSi strained stripes are described and their relative importance is discussed. Relaxation of stresses in the middle of the layers with I/h( =half-width/thickness) varying from 3 to 100 is calculated including the efFect of the two mechanisms which are important in this range. The values calculated in this manner agree with our recent finite element calculations. Since the stresses in the stripes in the two orthogonal directions are not

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We investigated in detail the strain relaxation behaviour of metastable tensile-strained Si 1−y C y epilayers on Si(001) by comparing the layers before and after an annealing step using a variety of different diagnostic methods. The dominant strain-relieving mechanism is the formation of carbon-containing interstitial complexes and/or silicon carbide nanoparticles, similar to the behaviour of carbon in silicon under thermodynamical equilibrium conditions (concentrations below the solid bulk solubility limit). We did not observe any carbon out-diffusion. To grow material suitable for device applications, all carbon atoms should be incorporated substitutionally. There is only a very narrow temperature window for perfect epitaxial growth of such layers, limited on one side by the possible formation of interstitial carbon complexes and on the other side by the deterioration of epitaxial growth at low temperatures. The carbon concentration should not exceed a few per cent to avoid strain-driven precipitation.

Changes in the densities of dislocations on distinct slip systems during stress relaxation in thin aluminium layers: The interpretation of xray diffraction line broadening and line shift

10-nm-thick germanium layers have been grown on Si(100) with and without antimony as a surfactant, and investigated by RHEED, TEM, and XPS. We obtained smooth epitaxial germanium layers with the antimony surfactant by passing through an island formation stage. These islands, formed below 400 °C, are of different structure than the islands obtained without surfactants. A possible mechanism for the "smoothing out" of islands developed in the beginning stage of surfactant-controlled solid phase epitaxy is proposed.