Electrothermal issues in 4H-SiC 600 V Shottky diodes in forward mode: Experimental characterization, numerical Simulations and analytical modeling

The electrothermal behavior of 4H-SiC 600 V Schottky diodes operated in forward mode is analyzed through numerical and analytically-based simulations. It is shown that the unexpected occurrence of voltage surges systematically detected in state-of-the-art devices is a thermally-induced effect due to the compound contribution of a) the negative temperature coefficient of the forward current at high voltages and b) the relatively high package-to-ambient thermal resistance. As a main result, it is demonstrated that the proposed approaches are suitable to accurately predict the value of a "critical" current density beyond which voltage surges may arise.