Modeling turn-off voltage rise in SOI LIGBT

Abstract

The behavior of the drain voltage rise of the Lateral IGBT during inductive turn-off is studied in detail. Numerical simulations show that, if compared with the well known vertical IGBT, the Lateral IGBT presents a differences in the on-state stored charge and in the growth of the depleted region that result in a different drain voltage rise.In this paper a complete model for the voltage rise is devised through an accurate calculation of the equivalent output capacitance. The model is in excellent agreement with twodimensional simulations. Further, the paper shows that previously proposed models, which targeted the vertical IGBT, are not adequate for the description of the turn-off voltage rise in the Lateral IGBT.