A computational study of short-channel effects in double-gate junctionless graphene nanoribbon field-effect transistors

摘要

As the channel length shrinks below the 10-nm regime, emerging materials, junctionless technology, and multiple-gate geometries provide an excellent combination to continue progress towards lower-cost high-performance ultrascaled devices. In this study, the double-gate junctionless (JL) graphene nanoribbon field-effect transistor (GNRFET) and its conventional counterpart (C-GNRFET) are compared in terms of short-channel effects (SCEs) using a quantum simulation. The computational approach is based on solving the Schrodinger equation using the mode-space nonequilibrium Green's function formalism coupled self-consistently with a Poisson equation in the ballistic limit. The analysis of gate length downscaling shows that the JL GNRFET exhibits better leakage current, subthreshold swing (SS), drain-induced barrier lowering, and threshold voltage roll-off in comparison with the conventional GNRFET. In addition, we reveal that a decrease in the n-type doping concentration can enhance the above-mentioned characteristics of both devices. The results indicate that the JL GNRFET can mitigate critical issues and enhance the immunity to SCEs of the GNRFET, making it a promising candidate for high-performance ultrascaled (sub-5-nm) technology.