AN ANALYTICAL MODEL FOR SNAPBACK IN N-CHANNEL SOI MOSFETS

At large drain voltages, the measured transfer characteristics of n-channel SOI transistors with either the body tied to the source or floating show hysteresis and current jumps which can be attributed to the snapback phenomena. An analytical model is developed in this paper for predicting the observed characteristics. This model is based on nonlinear feedback principles to account for the interactions among the impact ionization current, the body-to-source forward bias, the threshold voltage, and the drain current. Results obtained from this model show good agreement with experimental data measured from SIMOX devices fabricated on 0.3-mu-m epi film.