The growth of germanium at low temperature by ultrahigh vacuum chemical vapor deposition on Si(001) is investigated in real time by reflection high-energy electron diffraction. These observations are complementarily checked by atomic force microscopy, Rutherford backscattering spectrometry, transmission electron microscopy, and x-ray diffraction experiments. It can be seen that the currently observed Stranski–Krastanov-related two-dimensional (2D) to three-dimensional transition is avoided at 330 °C and that the major part of the relaxation process occurs during the deposition of the first two monolayers. Then, the measured in-plane lattice parameter evolves slowly and approaches that of bulk Ge after deposition of 50 monolayers. The corresponding relaxation equals 83%. The resulting surface is flat, with a rms roughness of 0.55 nm. The relaxation is found to be mainly due to misfits dislocations located at the Ge/Si interface. Regrowth experiments at 600 °C show that the low-temperature films are not stable for thicknesses below 27 nm. In spite of the nearly complete relaxation observed for 7.5 nm, a much higher thickness is needed to enable a continuous 2D growth at 600 °C. Finally, a 500-nm-thick film, obtained with a low-temperature Ge buffer and with a Ge regrowth at high temperature, exhibits a channeling-to-random Rutherford backscattering spectrometry ratio (min) of 4%, which indicates a good crystalline quality. ©2005 American Institute of Physic

The rate of residual-resistivity increase and the isochronal recovery have been studied on the fcc metals Al, Ni, Cu, Pd, Ag, Pt, and Au irradiated at 4.6 K with reactor neutrons to a dose of about 10' fast neutrons/cm2.The rate of resistivity increase is nonlinear as a function of irradiation-induced resistivity; computer analysis shows that the data are best fitted with an expression having up to third-order terms in hp. There are deviations from simple damage-rate theory in all cases, but an anomalous negative deviation from a linear law (convex curvature) is observed in Ni, Pd, Pt (and Fe). This behavior is most probably caused by a decrease of the specific Frenkel-defect resistivity due to defect clustering, an effect which should contribute in all metals after fast-neutron irradiation to high doses. Saturation values of resistivity and defect concentration as well as recombination volumes have been obtained more accurately than from previous work.The isochronal recovery is compared with previous lower-dose data. Stage I decreases and stage III increases with increasing neutron dose. After high-dose irradiation, correlated recovery in stage III becomes dominant in the case of Al, Cu, Ag, and Au. 165285

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