An analytical (classical) subthreshold behavior model for symmetrical fully-depleted SOI double-gate MOSFET's

Two dimensional device-physics-based analytical models are developed for subthreshold behavior in fully-depleted SOI double-gate MOSFET's. An analytical solution of Poisson's 2-D equation is employed to establish the design equation for the subthreshold behavior in the fully-depleted SOI double-gate MOSFET's. The concept of effective conducting path explains the silicon film thickness (t(si)), front and back oxide thickness (t(ox)) and doping density (N-A) unified dependence of subthreshold swing (S). Furthermore, alone, with the effective conducting path, the minimum channel potential is used to precisely predict the threshold voltage roll-off of the SOI double-gate MOSFET's. This analytical model not only gives physical insight into the fully-depleted SOI double-gate MOSFET's device physics, but also provides basic designing guidelines for fully-depleted double-gate MOSFET's.