The understanding of the impact of efficiently optimized underlap length on analog/RF performance parameters of GNR-FETs

The aim of this study is to examine the analog/RF performance characteristics of graphene nanoribbon (GNR) field-effect transistors (FETs) using a novel technique called underlap engineering. The study employs self-consistent atomistic simulations and the non-equilibrium Green's function (NEGF) formalism. Initially, the optimal underlap length for the GNR-FET by device has been determined evaluating the ON-current (I(ON)) to OFF-current (I(OFF)) ratio, which is a critical parameter for digital applications. Subsequently, the impact of underlap engineering on analog/RF performance metrics has been analyzed and conducting a comprehensive trade-off analysis considering parameters such as intrinsic-gain, transistor efficiency, and device cut-off frequency. The results demonstrate that the device incorporating the underlap mechanism exhibits superior performance in terms of the I(ON)/I(OFF) ratio, transconductance generation factor (TGF), output resistance (r(0)), intrinsic gain (g(m)r(0)), gain frequency product (GFP), and gain transfer frequency product (GTFP). However, the device without the underlap effect demonstrates the highest transconductance (g(m)) and cut-off frequency (f(T)). Finally, a linearity analysis has been conducted to compare the optimized GNR-FET device with the conventional GNR-FET device without the underlap effect.