Metrics for performance benchmarking of nanoscale Si and carbon nanotube FETs including device nonidealities

This paper proposes a simple and accurate expression for inverter effective drive current for nanoscale Si and carbon nanotube FET (CNFET) performance benchmarking. The choice of I_eff=(I_NL+I_NM+I_NH-I_P)/3, where I_NL=I_DS(N-FET) (V_GS=0.5V_DD, V_DS=V_DD), I_NM=I_DS(N-FET)(V_GS=0.75V_DD, V_DS=0.75V_DD), I_NH=I_DS(N-FET) (V_GS=V_DD, V_DS=0.5V_DD), and I_P=I_SD(P-FET) (V_SG=0.25V_DD, V_SD=0.25V_DD), includes the effects of both the nFET and the pFET of an inverter and accurately captures the inverter delay performance over many CMOS technology nodes and in the presence of device nonidealities. The proposed metric indicates that the performance enhancement of CNFETs over Si MOSFETs is not as large as that predicted by I_Dsat in a circuit environment because of the nonideal I-V characteristics.