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Solid phase epitaxy of 3500-Å-thick GexSi1−x (0.04≤x≤0.12) films on (100) Si substrates has been investigated. The thickness of regrown layers increased linearly with annealing time in the temperature range of 475–575 °C. The regrowth rates of stressed alloys were less than those of pure Si, while stress-relaxed alloys have larger rates than Si. The difference in regrowth rates was explained by the activation-strain tensor model (Aziz, Sabin, and Lu, to be published in Phys. Rev. B). The first element of the activation-strain tensor obtained in this experiment was in excellent agreement with that deduced by Aziz et al. For low Ge concentrations (x<0.08), the recrystallized region was of good crystalline quality. However, threading dislocations were observed in a stressed Ge0.1Si0.9 alloy after complete recrystallization. During the regrowth at 550 °C, the Ge-Si alloy first regrew coherently up to 300 Å, above which threading dislocations started to nucleate. On the other hand, no dislocations were detected in the regrown layer of a stress-relaxed Ge0.1Si0.9 alloy sample.

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In situ resistance measurements, x-ray diffraction, Rutherford backscattering spectrometry, transmission electron microscopy, isothermal and constant heating rate differential scanning calorimetry and Auger electron spectrometry depth profiles have been used to investigate the interactions in copper and magnesium thin films leading to the growth of Cu2Mg and CuMg2 intermetallics. The effect of exposing the reacting interfaces to controlled exposure of oxygen on the nucleation and growth kinetics of such intermetallics was also investigated. It is found that the first phase to form is CuMg2, at about 200–215 °C. It is determined that the formation of CuMg2 occurs by a two step process consisting of nucleation and growth. The nucleation of CuMg2 takes place in a region composed of a Cu/Mg solid solution. The nuclei form at certain preferred sites and grow in directions both parallel and perpendicular to the surface, eventually leading to a continuous CuMg2 layer. The growth of CuMg2 nuclei in the plane of the original interface occurs at a constant rate, whereas the growth in a direction perpendicular to the original interface is found to be diffusion limited. In the presence of excess copper Cu2Mg forms at higher temperatures, with complete conversion to Cu2Mg occurring at about 380 °C. When the Cu surface is dosed with oxygen prior to Mg deposition, ramp rate differential scanning calorimetry (DSC) shows that the nucleation and growth of CuMg2 as well as the growth of Cu2Mg are not disturbed. Dosing the Mg surface with oxygen results in significant changes in the growth of the two phases. In this case a thin MgO layer is formed at the oxygen dosed surface, lateral growth of CuMg2 is unaffected, but vertical growth of CuMg2 across the oxygen dosed interfaces is delayed by 25–30 °C. The growth of Cu2Mg is also shown to be delayed, by 22–54 °C due to the interfacial oxygen dose.