Formation of Silicide Nanowires by Annealing of Atomic Layer Deposition Cobalt/Silicon Core-Shell Nanowires

Abstract

Co/Si core-shell nanowires (NWs) were fabricated by using highly conformal thermal atomic layer deposition (TH-ALD) of Co and the formation of Co silicide NWs by annealing was investigated. When Co/Si core-shell NWs were annealed without capping layer, no Co silicide was observed due to oxygen contamination. To prevent oxygen contamination, in situ TH-ALD Ru was used for capping layer utilizing its excellent conformality suitable for 3-D nanostructures as well as thermal stability. The scanning transmission electron spectroscopy analysis showed Si NWs are perfectly wrapped by TH-ALD Ru/Co films, resulting in the formation of Ru/Co/Si core-shell NWs. By annealing Ru/Co/Si core-shell NWs, CoSi 2 was formed above T a = 800 {degree sign}C. This silicidation by using TH-ALD Co and Ru can be effectively used for the fabrication of future nanoscale devices.