Voltage oscillations during surge pulses induced by self-extinguishing non-destructive second breakdown in pn-junction diodes

PN-junction diodes with different breakdown voltages have been subjected to surge pulses per the standard IEC 61000-4-5 and their transient behaviour has been studied. For medium breakdown voltages (20-40 V) at high surge currents large transient oscillations in the voltage drop across the diodes are observed. After such an event, the devices are still operational. 3D electro-thermal TCAD simulations have been done to understand the phenomenon. A comparison between measurement and simulation reveals that the periodic voltage drop is caused by non-destructive second breakdown.