A Carrier-Based Analytic Model for Undoped Ultra-Thin-Body Silicon-on-Insulator (UTB-SOI) MOSFETs

This paper presents a carrier-based continuous analytic I-V model for long channel undoped (lightly doped) Ultra-Thin-Body Silicon-on-Insulator (UTB-SOI) MOSFETs. It is based on the solution of PoissonBoltzmann equation, and the current continuity equation of 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, sub-threshold) and traces the transition between them. This preliminary model has been verified by comparing with long channel results generated by two-dimensional simulator. The predicted I-V characteristics also show in a good agreement with twodimensional 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 quantum mechanical effect, doping profile effect, short-channel effects, and polydepletion effect are integrated into it.