Schottky-Barrier Metal–Oxide–Semiconductor Field-Effect Transistors as Resonant Tunneling Devices

Abstract

The current–voltage characteristics of double-gated Schottky-barrier metal–oxide–semiconductor field-effect transistor (MOSFET) 10 nm in length and with body thickness of 3 nm is numerically studied, illustrating a similarity between the rectangular quantum well cavity in conventional resonant tunneling diodes and the parabolic-like cavity created by a pair of Schottky junctions in scaled Schottky-barrier MOSFETs. Assuming ballistic transport for electrons within effective mass approximation, the appearance of negative differential resistance due to the resonant tunneling effect between the Schottky junctions of 0.75 eV height is confirmed by non-equilibrium Green's function simulation. In such scaled Schottky-barrier MOSFETs, the tunneling electrons by themselves determine the shape of resonant potential, through the charge terms in electrostatic field equations. Using both the Poisson equation and the Laplace equation, we highlight the importance of the self-consistency for realizing successful resonant tunneling operation in scaled Schottky-barrier MOSFETs.