Nonequilibrium Green's function treatment of a new nanoscale dual-material double-gate MOSFET

In this paper the electrical characteristics of a novel nanoscale double-gate (DG) silicon-on-insulator(SOI) MOSFET, in which the front gate consists of two materials with different work functions, have been investigated by a full quantum-mechanical simulation. The simulations have been done by the self-consistent solution of 2D Poisson–Schrödinger equations, within the nonequilibrium Green's function (NEGF) formalism. The quantum simulation results show that the new structure decreases significantly the leakage current and drain conductance and increases the on–off current ratio and voltage gain as compared to the conventional DG SOI MOSFET. In this new structure, the potential in the channel region exhibits a step function that ensures the screening of the drain potential variation by the gate near the drain, resulting in suppressed short-channel effects like the drain-induced barrier lowering (DIBL) and hot-carrier effect.

Research Highlights
► Because of reduction of quantum mechanical tunneling through the source to channel barrier, DMDG SOI structure decreases off-state current and subthreshold swing.
► DMDG SOI structure increases on-off current ratio and voltage gain.
► DMDG SOI structure with fixed channel length and larger gate material 1 decreases subthreshold swing and transconductance and increases on-off current ratio.