Impact of geometry-dependent parasitic capacitances on the performance of CNFET circuits

Intrinsic carbon-nanotube field-effect transistors (CNFETs) have been shown to have superior performance over silicon transistors. In this letter, we provide an insight how the parasitic fringe capacitance in state-of-the-art CNFET geometries impacts the overall performance of CNFET circuits. We show that unless the device (gate) width can be significantly reduced, the effective gate capacitance of CNFET will be strongly dominated by the parasitic fringe capacitances, and the superior performance of intrinsic CNFET over silicon MOSFET cannot be achieved in circuit.