Quantum transport of sub-5 nm InSe and InSSe monolayers and their heterostructure transistors.

The emerging two-dimensional (2D) semiconductors hold a promising prospect for sustaining Moore's law benefitting from the excellent device electrostatics with narrowed channel length. Here, the performance limits of sub-5 nm InSe and InSSe metal-oxide-semiconductor field-effect transistors (MOSFETs) are explored by quantum transport simulations. The van der Waals heterostructures prepared by assembling different two-dimensional materials have emerged as a new design of artificial materials with promising physical properties. In this study, device performance was investigated utilizing InSe/InSSe van der Waals heterostructure as the channel material. Both the monolayer and heterostructure devices can scale Moore's law down to 5 nm. A heterostructure transistor exhibits a higher on-state current and faster switching speed compared with isolated monolayer transistors. This work proves that the sub-5 nm InSe/InSSe MOSFET can satisfy both the low power and high-performance requirements for the international technology roadmap for semiconductors in the next decade and can provide a feasible approach for enhancing device performance.