Estimation of surface potential variation in short channel MOSFET by solving 2D Poisson´s equation

Advances in technology leads to dramatic lowering of MOSFET channel length. However short channel effects (SCE) degrade device performance and put a limit to scaling down of device dimensions. Drain induced barrier lowering (DIBL) is such an effect where threshold voltage rolls off and sub-threshold current increases significantly. Study of the surface potential is important for understanding DIBL. In this paper we propose a numerical model to calculate the variation in surface potential by solving the 2-D Poisson´s equation, starting from a more accurate expression for the charge distribution. The results agree with the expected trend.