A two-dimensional electrostatic model for degraded LDD-nMOSFETs including spatial and energy distribution of hot-carrier-induced interface traps

A two-dimensional electrostatic model for degraded short channel lightly doped drain (LDD)-nMOSFETs is presented. The model is based on a numerical solution of the Poisson equation using the five-point finite difference approximation. The model takes into account all device details including doping profiles and spatial and energy distribution of hot-carrier induced interface traps in the LDD region. Potential and charge distributions within the device in weak (subthreshold) and strong inversion regimes have been extensively studied. The validation of the model has been carried out through comparison between simulated I-V characteristics in the linear region and published experimental data. The results obtained have shown that the drain current is greatly affected by the energy distribution of interface traps, especially in the low gate voltage range (near-threshold and subthreshold).