Modeling of subthreshold characteristics of deep-submicrometer FD devices

A third-order quasi-cubic silicon film potential function in the vertical direction is assumed for FD-SOI device, and the surface potential formula is obtained via solving the two-dimensional Poisson equation in the subthreshold region. The surface potential model in the deep-submicrometer FD device is presented by introducing some new parameters to describe the DIBL effect. Based on it, a drain current model in the subthreshold region is developed, which can predict the accurate sub-threshold drain current characteristics. The models are verified by comparing with the two-dimensional device simulator, MEDICI.