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.