Mechanism and Physical Model of the Single-Event Leakage Current for SiC JBS Diodes

Abstract

The single-event leakage current (SELC) mechanism of the silicon carbide (SiC) junction barrier Schottky (JBS) diode is thoroughly investigated in this work. A comprehensive physical model to quantify the degree of SELC for the JBS diode is also proposed. From the collected experimental results, it is found that the leakage current of the SiC JBS diode increased with the increase in both the reverse bias voltage under irradiation and the total fluence. According to the results of the current response during irradiation and the emission microscope (EMMI) after irradiation, it can be inferred that the leakage current degradation of the samples originated from the accumulation of the Schottky junction’s area with a barrier reduction by the ion-induced local high temperature. Taking the degradation mechanism into account, a novel physical model is developed with the help of TCAD simulations. This model clearly highlights the relationship between the degradation (i.e., Schottky barrier height reduction and amplification of the leakage current) and the irradiation conditions (i.e., reverse bias voltage and fluence). This work provides valuable insights into the underlying origins of the SELC effect and its potential mitigation in SiC JBS diodes.