Structural trends in Si dots formation on SiC surfaces using CVD environment

We report on the formation of Si dots on SiC surfaces, using chemical vapor deposition technique. Small nanometric objects, with lateral sizes and heights down to 10 and 4 nm respectively, can be obtained, letting expect quantum confinement in the formed dots. The influence, both of the substrate properties and the growth temperature on the dots structure, shape and density, is investigated by means of X ray diffraction, X ray photoemission, scanning electron microscopy, atomic force microscopy and cathodoluminescence. Growing the Si dots on hydrogenated SiC surfaces allows to form (1 1 0) preferentially oriented silicon crystalline objects with densities ranging from 109 to some 1011 cm−2 in dependence on the temperature of growth (850-950 °C). At the opposite, starting the growth on graphitized SiC surfaces significantly modifies the dots properties. In that case, no specific crystalline direction can be evidenced, due to the formation either of Si/SiC dots having a core/shell structure or of fully converted SiC dots.