One-dimensional Au/Si heterojunction-microstructure and phase evolution under electron beam irradiation

A special type of Au/Si nanowire heterojunctions, which are wrapped by SiO2 surface layer, is demonstrated in this work. Nanochannels exist in-between the Si-core/SiO2-sheath close to the junction, which provides a flowing path for the Au at elevated temperatures. The Au-Si interactions during the reversible flowing process lead to an interesting phase evolution of the junction system, which eventually result in self-formation of the secondary nanostructures at the original Si/SiO2 interface. The observed microstructure/phase evolution of the Au-Si nanowire junction under the focused electron beam irradiation suggests an approach to modify and pattern the Si nanowire surface, which may have potential applications in the nanoelectronic industry. (c) 2005 American Institute of Physics.