A study of the effect of the interface roughness on a DG-MOSFET using a full 2D NEGF technique

摘要

The effect of the surface roughness on the electron transport of a double gate nano MOSFETs has been investigated. The study has been carried out using a simulator based on the two-dimensional non-equilibrium Green's function (NEGF) formalism coupled self-consistently with Poisson's equation. An appropriate control volume discretisation scheme for the Poisson and Green's function equations has been implemented in order to describe properly the surface roughness. The two-dimensional electron and current density landscape for the device with surface roughness exhibit strong inhomogeneity as compare with the smooth interface case. Devices with different randomly generated surface roughness patterns have been compared. At nanodevice scale the effects of the specific profile of the surface roughness do not self-average. The total macroscopic current pattern follows the microscopic detail of the roughness. While the related threshold voltage fluctuations are in the range of 100mV, the subthreshold slope remains quite similar between the different devices