Stability of silicon carbide Schottky diodes against leakage current thermal runaway

Thermal stability is mandatory for the application of power semiconductor devices. Thermal runaway as a consequence of the feedback loop of increasing temperature and increasing leakage current is one risk, especially for Schottky-diodes featuring particular blocking characteristics. In this work the blocking characteristics of modern SiC-Schottky diodes including MPS and JBS types were measured and the stability was investigated by means of theoretical considerations as well as measurements. Even the worst devices are thermally stable far beyond their datasheet limits and have to be mistreated to show thermal runaway. For the time being thermal runaway is, thus, not a limiting factor for the thermal design of SiC-diodes. However, when going to the much higher operating temperatures promised by SiC the picture looks quite different again.