Gate Field‐Induced Dynamic Schottky Barrier Height Reduction in Bilayer MoS2 for Sub‐60 mV/dec Schottky Barrier FETs

ABSTRACT Bilayer MoS2 exhibits bandgap narrowing under a vertical electric field due to inversion symmetry breaking, with the extent of reduction scaling proportionally with field strength. Leveraging this intrinsic property, this study investigates its impact on the performance of bilayer MoS2 Schottky barrier field‐effect transistors, with a particular focus on the role of Schottky barrier height reduction in improving subthreshold swing. Density functional theory calculations quantify field‐dependent shifts in the conduction and valence band edges, which are integrated into transport simulations considering thermionic emission and tunneling at the metal‐semiconductor interface, as well as drift‐diffusion in the channel. The barrier height reduction achieves a subthreshold swing of 44.7 mV/dec in a bilayer MoS2 FET with a 2 nm HfO2 gate dielectric, representing a 37.5% improvement. In a CMOS inverter configuration, barrier height reduction leads to improvements in switching speed by up to 38% and reduces total power consumption by approximately 5%, demonstrating its effectiveness in enhancing both performance and energy efficiency.