Characterization of SiGe Quantum Dots on SiO[sub 2] and HfO[sub 2] Grown by Rapid Thermal Chemical Deposition for Nanoelectronic Devices

Silicon-germanium quantum dot growth between 500 and 525°C using a -based chemistry was studied. The nucleation and growth of the SiGe dots were quantified by measuring the nuclei density and the concentration of Ge on and using scanning electron microscopy and atomic force microscopy. The effect of and pretreatment on the surface was investigated. It was found that Si atoms dominate the formation of the critical nuclei and Ge atoms impinge on these Si atoms to grow the SiGe dots. The Si atoms that terminate defect sites on and the partial pressure determine the densities of SiGe dots. The growth of SiGe dots is limited by the partial pressure, which reduces the activation energy of disilane decompositions in the surface-reaction-limited regime and desorption sites of H from the substrate.