Avalanche Breakdown Stability of High Voltage (1430 V) 4H-SiC p+–n0–n+ Diodes

The electrothermal breakdown in high-voltage (1430 V) 4H-SiC p+–n0–n+ diodes with an n0-base thickness of 7.5 μm, a donor concentration of 8.0 × 1015 cm–3, and 4.9 × 10–4 cm2 in area are studied. The stability of the diodes to avalanche breakdown is characterized by the maximum energy of a single avalanche current pulse that can be scattered by a diode until its catastrophic destruction. At a pulse duration of ~1 μs, the energy maximum is 1.4 mJ (2.9 J/cm2). It is shown that diode destruction is caused by local overheating of the diode structure to a temperature of ~1600 K at which the intrinsic carrier concentration becomes higher than the doping donor concentrations in the blocking n0-type base.