Cosmic ray induced breakdown in high voltage semiconductor devices, microscopic model and phenomenological lifetime prediction

Recently a new cosmic ray induced failure mode of high current-high voltage semiconductor devices has been discovered. The failure affects diodes, thyristors and GTO's as well. it consists of a localised breakdown in the bulk of the device and is not related to junction termination instabilities. The onset of the breakdown occurs without a precursor within a few nanoseconds. The failure rate is constant in time, strongly dependent on applied voltage and nearly independent of temperature. The effect is reduced by screening and thus it is generally believed that the failure is cosmic ray induced. We have measured GTO's, diodes and thyristors of 2.5 kV and 4.5 kV ratings at various test voltages and also have obtained field data from customers.