Conduction mechanisms of the reverse leakage current of 4H-SiC Schottky barrier diodes

Abstract

A new numerical method for determining the reverse transition voltage between thermionic and tunneling mechanisms has been performed for 4H-SiC Schottky barrier diodes. The idea of this method is based on equality between thermionic emission and the tunneling process and both are combined with the barrier lowering model. Application of this method shows a strong discrepancy between our results and those deduced from Padovani-Stratton conditions. The reverse transition voltage versus the temperature plot exhibits an unexpected peak at low temperatures which means that the thermionic emission mechanism predominates at low temperatures. The reverse transition voltage increases linearly with the increase in barrier height, the effective mass and the inverse of doping concentration. In order to predict the reverse transition voltage as a function of temperature, doping concentration and barrier height for a 4H-SiC Schottky barrier diode, an analytical model has been proposed.