Failure rates of fast recovery diodes due to cosmic rays

for a better worldTM In the early 1990’s a new failure mode for high current, high voltage semiconductor devices was discovered. The failure mode was of considerable practical significance and caused a series of equipment malfunctions in the field. This failure mode affects all kind of devices like diodes, thyristors, GTOs, IGCTs, IGBTs, etc. It consists of a localised breakdown in the bulk of the devices and is not related to junction termination instabilities. The location of the breakdown spot on the wafer is random. The onset of the breakdown occurs without a precursor within a few nanoseconds and there is no sign of early failures or wear out. The failure rate is, thus, constant in time but strongly dependent on the applied voltage and shows a small dependence on temperature. Application Note 5SYA 2061-00