Variability sources in nanoscale bulk FinFETs and TiTaN- a promising low variability WFM for 7/5nm CMOS nodes

A systematic methodology to segregate different variability sources from electrical measurements, in sub-10nm W
_fin
FinFETs, is proposed. The threshold voltage variation, coming from gate-metal work-function and oxide charge variations, is shown to be the major contributor to in-wafer variability. The contribution of FER, GER and RDF to V
_t
variability is negligible. TiTaN, a new work function metal (WFM) for the metal gate-stack, is introduced and it provides ~37% less total and ~27% less random variability.