Measurement-based analysis of the parasitic resistance (Rpara ) of FinFETs was extended to investigation of Rpara fluctuation, which could cause severe on-current variation. Rpara was obtained from the intercept in the linear relationship between measured on-resistance and gate length for FinFETs of various dimensions. A significant increase in Rpara is observed for fin thickness below 25 nm due to dopant loss from the ultrathin extension during processing. Rpara variation was evaluated for 45 FinFETs with an average fin thickness of 16 nm. Significant Rpara variation is observed and correlates with the variation of fin thickness.
- Parasitic resistance
- Source-drain (S/D)