Investigation of 6-armchair graphene nanoribbon tunnel FETs

Abstract

A simulation-based study of an n-type six-dimer-line armchair graphene nanoribbon (6-AGNR) tunnel field-effect transistor with asymmetric reservoir doping density is carried out. Tunnel field-effect transistor (TFET) structures are proposed based on a detailed investigation of the device behavior for different applied voltages, channel lengths, temperatures, insulator thicknesses, dielectric constants, and source impurity molar fractions. By suppressing the tunneling transmission in the off-state, the channel length of the device using HfO2 can be scaled down to 5 nm without increasing the leakage current. When using a supply voltage of 0.4 V, the ION/IOFF ratio reaches a high value of 3.6 × 1010 for the device with a 5-nm channel. Besides, a subthreshold swing (SS) of 3.8 mV/dec is measured for the same GNR-TFET. The high-performance 10-nm-channel device, when supplied with 0.6 V, exhibits a boosted ION value of up to 4.3 × 103 µA/µm, with SS, gm, and Dini values of 28 mV/dec, 11 µS, and 11 fs, respectively. Nevertheless, conventional GNR-TFETs with various channel lengths exhibit rather outstanding characteristics. Such 6-AGNR TFETs display promising functionality for application in future digital and analog integrated circuits.