Comprehensive analysis of variability sources of FinFET characteristics

FinFET performance variability is comprehensively investigated for undoped/doped channels with various gate materials. By evaluating the influence of channel doping, fluctuation of gate length and that of fin thickness, it is found that gate workfunction variation (WFV) is the dominant source of V_t variation for the undoped FinFET and that the WFV increases with scaling of gate area. In addition, it is demonstrated that the extension doping optimization successfully reduces the variation of parasitic resistance (R_p) due to fin thickness fluctuation as well as R_p itself. FinFET-SRAM performance in 20-nm-L_g node is predicted by the compact model using the measured variation data.