A Compact Virtual-Source Model for Carbon Nanotube FETs in the Sub-10-nm Regime-Part I: Intrinsic Elements

We present a data-calibrated compact model of carbon nanotube (CNT) FETs (CNTFETs) based on the virtual-source (VS) approach, describing the intrinsic current-voltage and charge-voltage characteristics. The features of the model include: 1) carrier VS velocity extracted from experimental devices with gate lengths down to 15 nm; 2) carrier effective mobility and velocity depending on the CNT diameter; 3) short channel effect such as inverse subthreshold slope degradation and drain-induced barrier lowering depending on the device dimensions; and 4) small-signal capacitances including the CNT quantum capacitance effect to account for the decreasing gate capacitance at high gate bias. The CNTFET model captures the dimensional scaling effects and is suitable for technology benchmarking and performance projection at the sub-10-nm technology nodes.