Prospect of ballistic CNFET in high performance applications

Abstract

With the advent of carbon nanotube technology, evaluating circuit and system performance using these devices is becoming extremely important. In this article, we present a quasi-analytical device model for intrinsic ballistic CNFET, which can be used in any conventional circuit simulator like SPICE. This simple quasi-analytical model is effective in a wide variety of CNFET structures as well as for a wide range of operating conditions in the digital circuit application domain. We also provide insight into 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 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. We further show that unlike conventional MOSFET, nanotube FETs are significantly less sensitive to many process parameter variations due to their inherent device structures and cylindrical gate geometry.