Promising Properties of a Sub-5-nm Monolayer MoSi2N4 Transistor

Abstract

Two-dimensional (2D) semiconductors have attracted tremendous interests as natural passivation and atomically thin channels that could facilitate continued transistor scaling. However, air-stable 2D semiconductors with high performance were quite elusive. Recently, extremely air-stable MoSi2N4 monolayer had been successfully fabricated [Hong et al., Science 369, 670 (2020)]. To further reveal its potential applications in the sub-5 nm MOSFETs, there is an urgent need to develop integrated circuits. Here we report first-principles quantum transport simulations on the performance limits of n- and p-type sub-5 nm monolayer (ML) MoSi2N4 metal-oxide-semiconductor FETs (MOSFETs). We find that the on-state current in the MoSi2N4 MOSFETs can be effectively manipulated by the length of gate and underlap (UL), as well as the doping concentration. Very strikingly, we also find that the n-type devices the optimized on-state current can reach up to 1390 and 1025 uA/um for the high performance (HP) and low power (LP) applications, respectively, both of which satisfy the International Technology Roadmap for Semiconductors (ITRS) requirements. Whereas, the optimized on-state current can meet the LP application (348 uA/um) for the p-type devices. Finally, we find that the MoSi2N4 MOSFETs have ultra-low subthreshold swing and power delay product, which have potential to realize the high speed and low power consumption devices. Our results show that MoSi2N4 is an ideal 2D channel material for future competitive ultrascaled devices.