An efficient threshold voltage model for ultra thin body double gate/SOI MOSFETs

In this paper, an efficient non-iterative approach for calculating the threshold voltage of the nanoscale double gate nMOSFET is presented. First, it is shown that the parabolic potential is a reasonable approximation for the body potential along the coordinate normal to the interfaces at the threshold of conduction. Then, the energies of confined carriers are determined by solving the Schrodinger´s equation using the WKB approximation. All the coefficients of the potential polynomial are represented analytically in the threshold condition. To assess the accuracy of the proposed model, its predictions have been compared to the results of a numerical simulator and a previously published model. It is also observed that the approach can be extended to an iterative threshold voltage model for 4-terminal fully depleted SOI structures with intrinsic or doped body.