A new 2-D analytic threshold-voltage model for fully depleted short-channel SOI MOSFET's

The exact solution of the 2-D Poisson equation for fully depleted SOI MOSFETs is derived by using a three-zone Green's function solution technique. Based on the derived 2-D potential distribution, the front and back surface potential distributions in the Si film are analytically obtained and their accuracies are verified by 2-D numerical analysis. The calculated minimum surface potential and its location are used to analyze the drain-induced barrier-lowering effect and further to develop an analytic threshold-voltage model. Comparisons between the developed analytic threshold-voltage model and the 2-D numerical analysis are made. It is shown that excellent agreements are obtained for wide ranges of device structure parameters and applied biases.>