Assessment of silicon MOS and carbon nanotube FET performance limits using a general theory of ballistic transistors

A simple model for ballistic nanotransistors, which extends previous work by treating both the charge control and the quantum capacitance limits of MOSFET-like transistors, is presented. We apply this new model to MOSFET-like carbon nanotube FETs (CNTFETs) and to MOSFETs at the scaling limit. The device physics for operation at ballistic and quantum capacitance limits are explored. Based on the analysis of recently reported CNTFETs, we compare CNTFETs to MOSFETs. The potential performance advantages over Si that might be achieved at the scaling limit are established by using the new model.