Performance evaluation of CNFET-based logic gates

As the physical gate length of current devices is reduced to below 65 nm, effects (such as large parametric variations and increase in leakage current) have caused the I-V characteristics to be substantially depart from those commonly associated with traditional MOSFETs, thus impeding the efficient development and manufacturing of devices at deep submicro/nano scales. Carbon Nanotube Field Effect Transistors (CNFETs) have received widespread attention, as one of the promising technologies for replacing MOSFETs at the end of the Technology Roadmap. This paper presents a detailed simulation-based assessment of circuit performance of this technology and compares it to conventional MOSFETs; the designs of different logic gates and the full adder circuit are simulated under the same minimum gate length and different operational conditions. It is shown that the power-delay product (PDP) and the leakage power for the CNFET based gates are lower than the MOSFET based logic gates by 100 to 150 times, respectively. The CNFET based logic gates demonstrate good functionality even at a 0.3 V power supply (while MOSFET based gates fail at 0.5 V).