Improving performance of armchair graphene nanoribbon field effect transistors via boron nitride doping

Abstract

Device performance of 10nm length armchair graphene nanoribbon field effect transistors with 1.5nm and 4nm width (13 and 33 atoms in width respectively) are compared in terms of Ion/Ioff, trans-conductance, and sub-threshold swing. While narrow devices suffer from edge roughness wider devices are subject to more substrate surface roughness and reduced bandgap. Boron Nitride doping is employed to compensate reduced bandgap in wider devices. Simultaneous effects of edge and substrate surface roughness are considered. Results show that in the presence of both the edge and substrate surface roughness the 4nm wide device with boron nitride doping shows improved performance with respect to the 1.5nm one (both of which incorporate the same bandgap AGNR as channel material). Electronic simulations are performed via NEGF method along with tight-binding Hamiltonian. Edge and surface roughness are created by means of one and two dimensional auto correlation functions respectively. Electronic characteristics are averaged over a large number of devices due to statistic nature of both the edge and surface roughness.