Low temperature synthesis of silicon nanowire arrays

In this paper, we report the synthesis of silicon nanowire arrays using Ga cluster tip-led growth at temperatures lower than 200 °C using gentle plasma and chloro-silane gas phase chemistry. No nanowire growth is observed in the absence of plasma indicating that atomic hydrogen is essential for selective dissolution of silicon in to molten Ga. The growth kinetics analysis suggests that silicon dissolution from vapor phase occurs through dehydrogenation of silyl radicals through reaction with dissolved hydrogen in Ga. Also, the mode of silicon dissolution from the vapor phase in to molten Ga determines tip-led versus bulk nucleation and growth from molten Ga droplets, i.e., selective dissolution through vapor-molten Ga interface allows for tip-led growth and silicon dissolution through solid Si film-molten Ga interface leads to bulk nucleation and growth. (paper)