The silicon transport in a silicon-germanium melt has been studied to address the issues of melt replenishment and seed production for the Czochralski growth of silicon germanium (SiGe) crystals. The growth of SiGe single crystals by the Czochralski method requires that the melt be replenished with silicon during the growth process due to the rejection of germanium into the melt during solidification. To facilitate the replenishment of the melt, an accurate knowledge of the dissolution rate of silicon into the melt and its transport through the melt is required. To address these issues, a number of experiments have been carried out on the dissolution of silicon into a germanium melt. Liquid phase diffusion growth experiments were also conducted for insight into transport and as a possible method for seed crystal production. The experiments encompassed various temperatures, crucible geometries, crucible translation, and magnetic field levels to determine optimum conditions for the most favorable dissolution rates and mass transport in the melt. Results have shown that replenishment from bottom of the crucible is most effective due to the enhanced silicon transport by buoyancy. The application of magnetic fields may also provide an effective mean to control the replenishment rate (mass transport rate) in the melt.
Successfully used recently for liquid Na and K the approach combined the linear trajectory approximation with the square-well model in the semi-analytical representation of the mean spherical approximation to calculate the self-diffusion coefficients is applied here to liquid Li and Rb. As well as earlier for Na and K, the results obtained are found to be in reasonable agreement with the available experimental data and confirm previous conclusion that the square-well model within the mean spherical approximation is quite useful for description of diffusion properties in liquid alkali metals.
Depth distribution of implanted species and microstructure of oxygen-containing Czochralski grown silicon (Cz-Si) implanted with light ions (such as H^{+}) are strongly influenced by hydrostatic pressure applied during the post-implantation treatment. Composition and structure of Si:H prepared by implantation of Cz-Si with H_{2}^{+}; fluence D = 1.7 × 10^{17} cm^{-2}, energy E = 50 keV (projected range of H_{2}^{+}, R_{p}(H) = 275 nm), processed at up to 923 K under Ar pressure up to 1.2 GPa for up to 10 h, were investigated by elastic recoil detection Rutherford backscattering methods and the depths distributions of implanted hydrogen and also carbon, oxygen and silicon in the near surface were determined for all samples. The defect structure of Si:H was also investigated by synchrotron diffraction topography at HASYLAB (Germany). High sensitivity to strain associated with small inclusions and dislocation loops was provided by monochromatic (λ = 0.1115 nm) beam topography. High resolution X-ray diffraction was also used.
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