Silicides for the 100-nm node and beyond: Co-silicide, Co(Ni)-silicide and Ni-silicide
As scaling progresses, conventional Co/Ti silicidation is facing difficulties related to the nucleation of the low resistive Co-disilicide phase during the second RTP step of silicidation. When linewidths, junction depths and silicide thicknesses are being reduced, the RTP2 thermal process window narrows down rapidly. It is expected that the process window can be widened by alloying the Co film with Ni, because the presence of Ni lowers the nucleation barrier for the Co-disilicide phase. Replacing Co-disilicide by Ni-monosilicide is a promising alternative because the same silicide sheet resistance can be obtained with 35% less silicon consumption.
ni-silicide sheet resistance co-silicide coni alloy junction leakage