Retarded oxidation of Si nanowires

Retarded thermal oxidation of Si nanowires is investigated. The oxidation behavior strongly depends on the wire curvature. The effect starts to evolve for a curvature larger than 0.05 nm, i.e., an original nanowire radius of 35 nm. For longer oxidation time and lower oxidation temperature, the effect of retarded oxidation gets stronger. The average values of the oxidation rate for small wires are reduced nearly by a factor of 2 compared to bulk < 100 > silicon. The authors suggest that the increased stress is responsible for the mechanism of retarded oxidation which cannot be decreased by the viscous flow of the oxide. (c) 2006 American Institute of Physics.