Quantum transport simulations of sub-5 nm bilayer Ga₂O₃transistor for high-performance applications

Two-dimensional (2D) semiconductors with bizarre properties show great application potential for nanoscale devices, which is regarded as the Si alternation to extend the Moore's Law in sub-5 nm era. In this study, we investigate the electronic structure and ballistic transport characteristics of sub-5 nm bilayer (BL) Ga₂O₃metal-oxide-semiconductor field-effect transistor (MOSFET) using the first-principles calculations and the nonequilibrium Green's function method. Quasi-direct band structure with bandgap of 4.77 eV is observed in BL Ga₂O₃, and high electron mobility of 910 cm²V^-1s^-1at 300 K is observed under the full-phonon scattered processes. Due to the enlarged natural length, the gate-controllable ability of 2D Ga₂O₃n-MOSFET is suppressed with the increased layer. The transport characteristic investigation indicates that BL Ga₂O₃n-MOSFETs can meet the latest International Technology Roadmap for Semiconductors requirement for high-performance application untilL_g= 4 nm. The figures of merits including on-current, intrinsic delay time, and power delay product are showing competitive potential with the reported 2D materials. With the help of underlap structure, the device performance can be further improved in the sub-3 nm region. Our results indicate that BL Ga₂O₃is a promising candidate for sub-5 nm MOSFET applications.