Monolayer WSi2N4: A promising channel material for sub-5-nm-gate homogeneous CMOS devices

Complementary metal oxide semiconductor (CMOS) devices require both n-type and p-type metaloxide-semiconductor field-effect transistors (MOSFETs), but achieving both types that meet the requirements of the International Technology Roadmap for Semiconductors (ITRS) at ultrashort gate lengths is a challenge. Recently synthesized two-dimensional crystal WSi2N4 exhibits high theoretical hole and electron carrier mobilities. In this study, we investigate the performance limits of double-gated (DG) monolayer (ML) WSi2N4 MOSFETs with sub-5-nm gate lengths using first-principles density-functional theory and the nonequilibrium Green's function method. Our results show that both the n-type and ptype DG ML WSi2N4 MOSFETs can meet the requirements of ITRS 2013 for high-performance (HP) applications at the 2028 technology node, even when the gate length is scaled to 3 nm. For low-power applications, the scaling limits for the gate lengths of the n-type and p-type DG ML WSi2N4 MOSFETs are 4 and 5 nm, respectively. Importantly, the ON-state currents of the n-type and p-type HP DG ML WSi2N4 MOSFETs are highly symmetric, highlighting the potential of ML WSi2N4 as a promising material for building next-generation CMOS devices, especially for HP applications.