A continuous analytic I?V model for long-channel undoped ultra-thin-body silicon-on-insulator (UTB-SOI) MOSFETs from a carrier-based approach
This paper presents for the first time a continuous analytic I–V model for long-channel undoped (lightly doped) ultra-thin-body silicon-on-insulator (UTB-SOI) MOSFETs from a carrier-based approach. It is based on the solution of the Poisson–Boltzmann equation and the current continuity equation of the Pao–Sah current formulation in terms of the mobile carrier concentration under an appropriate boundary approximation. The model is continuous and valid for all the operation regions (linear, saturation and sub-threshold) and traces the transitions between them. This preliminary model has been verified by comparison with long-channel results generated by a two-dimensional simulator. The predicted I–V characteristics also show a good agreement with two-dimensional numerical simulations for all ranges of gate and drain voltages, proving the validity of the analytical model. All these indicate that this model will be an ideal core model for UTB MOSFET modelling if the appropriate second-order effects such as the quantum-mechanical effect, doping-profile effect, short-channel effect and poly-depletion effect are integrated into it.