Process-induced Vt variability in nanoscale FinFETs: Does Vt extraction methods have any impact?

In this work, we have studied the effect of threshold voltage (V-t) extraction methods on in-wafer variability of sub-10nm fin-width FinFETs. Using six different V-t extraction techniques, it is experimentally demonstrated that the V-t variability is independent of the extraction technique. The significant variation in work-function and oxide-charges compared to mobility and series-resistance is shown to be the reason behind these observations. It is also shown that the inferences drawn from this work will hold true even for future CMOS nodes.