Wigner Function-Based Simulation of Quantum Transport in Scaled DG-MOSFETs Using a Monte Carlo Method

Source-to-drain tunneling in deca-nanometer double-gate MOSFETs is studied using a Monte Carlo solver for the Wigner transport equation. This approach allows the effect of scattering to be included. The subband structure is calculated by means of post-processing results from the device simulator Minimos-NT, and the contribution of the lowest subband is determined by the quantum transport simulation. By separating the potential profile into a smooth classical component and a rapidly varying quantum component the numerical stability of the Monte Carlo method is improved. The results clearly show an increasing tunneling component of the drain current with decreasing gate length. For longer gate lengths the semi-classical result is approached.