Performance dependency on doping level of carbon nanotube for ballistic CNTFETs

Carbon nanotube (CNT) could be exploited as a channel or source/drain region in field effect transistors (FETs). We theoretically investigate the impact of CNT doping level on a coaxially gated CNTFET's performance in the ballistic regime. The results show that the transconductance and subthreshold swing are independent of the CNT doping value. But threshold voltage and output conductance strongly depend on the channel doping level. It seems that the most important impact of CNT doping is the change in off-state current values resulting in a shift in the transfer characteristics of the device. However, it is possible to choose an optimal value of CNT doping to obtain the highest performance.