Aluminum mobility and interfacial segregation in fully silicided gate contacts

The mobility of aluminum implanted as a dopant of fully silicided nickel for advanced metal gates has been investigated following rapid thermal annealing at temperatures ranging from 160to700°C. Resonant nuclear reaction profiling using the Al27(p,γ)Si28 reaction was used for aluminum quantification and depth profiling. The results indicate that there is no significant aluminum loss in the whole annealing temperature interval. Furthermore, aluminum is seen to segregate near the interface with silicon oxide during metal silicidation, forming a stable layer of aluminum oxide.