Catastrophic failure of power silicon PN junctions at high temperature induced by the surface leakage reverse current

The operation of commercial power silicon devices, available at this time, is not possible above 175-200°C junction temperature, without risk of failure. The surface leakage reverse current component is a source of nonnegligible localized power dissipation at high temperature. An overheating at the junction peripheral surface is possible and the reverse current thermal runaway may lead to definitive material degradation at the junction edge. Typical I-V reverse characteristics from room temperature to above 200°C, from available devices on the market, are shown. The presence of the surface current for standard recovery and fast recovery high voltage junctions is outlined.