Understanding of the retarded oxidation effects in silicon nanostructures

A new understanding of the retarded or self-limited oxidation phenomenon observed during the oxidation of silicon nanostructures is proposed. The wet thermal oxidation of various silicon nanostructures such as nanobeams, concave/convex nanorings and nanowires exhibits an extremely different and complex behaviour. Such effects have been investigated by the mode\-lling of the mechanical stress generated during the oxidation process explaining the retarded or quasi self-limited regime. The proposed model describes the oxidation kinetics of silicon nanowires down to a few nanometers while predicting reasonable and physical stress levels at the Si/SiO$_{2}$ interface by correctly taking into account the relaxation effects in silicon oxide through plastic flow. Finally, this study gives more insight into the retarded or self-limiting oxidation phenomenon.