High-frequency analog GNR-FET design criteria

Some key aspects of the behavior of graphene nanoribbon (GNR) FETs for high-frequency analog applications are identified and discussed by means of a simulation study based on a full-quantum ballistic transport model. GNRs of width in the order of 10 nm are considered, where the small band-gap and the consequent leakage currents due to band-to-band-tunneling (BTBT) require a careful design. Simulations performed with a realistic model for source/drain metal contacts indicate that a proper choice of the drain doping profile can partially suppress BTBT currents. A 40-nm gate-length 2-nm SiO2 gate-dielectric GNR-FET can achieve a peak small-signal voltage gain of about 30 and a cut-off frequency well above 1 THz.