Modeling the schottky barrier properties of graphene nanoribbon schottky diode

Abstract

The increasing demand for small sized, low power consumption and high processing speeds have always been the pillars of transistor development. To meet the demands of the transistor, the current trend is to reduce the size of Metal Oxide Semiconductor Field Effect Transistor (MOSFET) into nanoscale regime because size plays an essential role in the performance of transistors. However, the extreme scaling of the size has brought new challenges as the MOSFET reaches its performance limit. In this respect, the Graphene Nanoribbon (GNR), a promising material that holds much potential for the future nanoelectronic devices, is introduced as a new material to overcome the limitation that exists in the conventional MOSFET. In this research, the analytical model of the GNR Schottky diode was presented to analyse the behaviour of metal-GNR interface. The work presents a simple model to analyse the current-voltage characteristic in the function of Schottky barrier properties such as the potential barrier and the Schottky barrier lowering effect of GNR contact. By using the analytical method, the analytical model for depletion region width, potential barrier, Schottky barrier lowering effect and the current-voltage characteristics of the GNR Schottky diode were presented. Besides that, the device structure of the GNR Schottky diode was built using Atomic Toolkit Virtual Nano Lab software to analyse the edge effect of metal-GNR interface. Based on the results, it is found that the potential barrier of GNR contacts is lower than conventional silicon contacts by at least half of it and the metal-Zigzag GNR interface shows promising potential to become interconnect as the interface is able to carry high current density up to 109 A/cm2. In addition, the proposed current-voltage characteristics model of GNR Schottky diode shows good agreement with experimental data and also with ATK Tools Simulation result.