Extensive Analysis of Gate Leakage Current in Nano-Scale Multi-gate MOSFETs

Excessive gate leakage is crucial for nanoscale metal oxide semiconductor field-effect transistors (MOSFETs), resulting in unnecessary static power dissipation and switching delay. Herein, we used three-dimensional modeling to understand the gate leakage behavior of various nanoscale MOSFETs, including fin field-effect transistor and gate all around MOSFET. We used Wentzel-Kramers-Brillouin approximation to compute the direct quantum tunneling-based gate leakage current. We performed all computations of quantum transport for gate leakage current through the non-equilibrium Greens function approach. Among the MOSFET structures under study, the gate all around MOSFET demonstrates the most profound gate leakage deviation with the gate material work function and oxide thickness. A detailed analysis of the dependence of the gate leakage on the metal work function is presented, and the charge density model is used to explain this dependence. This work explores the possibilities of controlling the gate leakage through gate material variations in different nanoscale multi-gate MOSFET architectures.