Bilayer GaN nanosheet: a potential transistor channel for next decade

Abstract

Gallium Nitride (GaN) is a promising third-generation semiconductor, and H-passivated buckled bilayer GaN exhibits unique electronic characters. Bilayer GaN metal-oxide-semiconductor field-effect transistors (MOSFETs) with a 5-nm gate length are evaluated using ab initio quantum transport simulations. Device performance is highly sensitive to electrode doping concentrations and underlap lengths. Specifically, the best-performing n-/p-type bilayer GaN MOSFETs demonstrate on-state currents of 1059/689 and 2037/1247 µA/µm, delay times of 0.053/0.078 and 0.047/0.073 ps, and power dissipations of 0.033/0.032 and 0.057/0.054 fJ/μm for low-power and high-performance applications, respectively. These performance metrics exceed the International Roadmap for Devices and Systems (IRDS) targets for the ‘5am eq’ technology node. Notably, bilayer GaN MOSFETs outperform monolayer MoS₂, InSe, InP, silicane, and germanane in terms of on-state current under identical operating conditions. Overall, bilayer GaN offers significant advantages as a next-generation transistor channel material and is well suited for operation under extreme environmental conditions due to the intrinsic properties of GaN.