Nucleation and growth of epitaxial silicide in silicon nanowires

Transition-metal silicides have been used in the salicide process to form gate and source/drain contacts in MOSFET devices. How to control silicide formation in shallow junction devices and the kinetics of single silicide phase formation between the Si and metal thin films have received extensive attention and study. As the trend of miniaturization of Si devices moves from 45 nm to smaller sizes, the formation of nanoscale metal silicides has attracted renewed interest in silicide formation. Nanostructures in Si nanowires have been studied for basic components in electronic and optoelectronics devices, especially for biosensors. Well-defined nanoscale building blocks such as ohmic contacts and gates on Si nanowires must be developed in order to be assembled into functional circuit components in future nanotechnology. It requires a systematic study of solid-state chemical reactions in the nanoscale to form these circuit components. In this review, we compare silicide formation in thin films and in nanowires and focus on the nucleation and growth of epitaxial silicides. The difference of silicide formation between the thin film case and the nanowire case, especially the kinetics of nucleation and growth, will be emphasized.