High-temperature behavior of SiC power diodes

Silicon Carbide devices are in theory able to operate at very high temperatures, but many mechanisms actually lower the limit. In this paper we describe two of these mechanisms: the thermal run-away, and the ageing of the device. Ageing effects are assessed through two different set-ups: SiC diodes in plastic packages are stored for long periods (up to 2000 hrs) in a furnace with a temperature ranging from 200 to 250°C, while bare die diodes are stored in vacuum at a temperature of 350°C. A study is then performed to assess whether the diodes under test, which have a MPS structure, are sensitive to thermal run-away. It is found that the mixed unipolar-bipolar architecture offers much more robustness than a pure Schottky Barrier Diode would.