Jun-taek Lee

Thermal stability of Al-1%Si-0.5%Cu/TiSi2 contact structure

Stable TiSi2 was formed by rapid thermal annealing (RTA) on single-crystal Si. Subsequently a 600 nm-thick Al-1%Si-0.5%Cu layer was deposited on the top of the formed TiSi2 followed by furnace annealing for 30 min at 400–600 ‡C in N2 ambient atmosphere. The thermal stability of Al-1%Si-0.5%Cu/TiSi2 bilayer and interfacial reaction were investigated by employing four-point probe, scanning electron microscopy (SEM) and Auger electron spectroscopy (AES). The composition and the phase of precipitates formed by the reaction of Al-1%Si-0.5%Cu with TiSi2 were studied by energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). It was found that the TiSi2 layer was consumed by the reaction between TiSi2 and Al-1%Si-0.5%Cu layer, resulting in precipitates at 550 ‡C. The results from EDS revealed that the precipitates were composed of Ti, Al and Si. The precipitates were identified as Ti7Al5Si12 ternary compound from XRD analysis.