Comprehensive analysis of Ion variation in metal gate FinFETs for 20nm and beyond

On-current (I_on) variation in metal gate FinFETs is comprehensively investigated with regard to the contributions of threshold voltage (V_t), parasitic resistance (R_para) and trans-conductance (G_m) variations, which are successfully extracted as the independent variation sources. It is experimentally confirmed that the G_m variation of the FinFETs exhibits a linear relationship in Pelgrom plot as well as the V_t variation, and is not reduced with scaling the gate dielectric thickness unlike the V_t variation. Perspective for beyond 20nm represents that the G_m variation will be the dominant I_on variation source. A solution to reduce the G_m variation for the FinFET is also proposed.