Irradiation experiments with high-voltage power devices as a possible means to predict failure rates due to cosmic rays

High-voltage diodes with active areas between 1 cm/sup 2/ and 32 cm/sup 2/ were irradiated either with carbon ions having energies between 17 MeV and 252 MeV or /spl alpha/-particles of 98 MeV or neutrons with energies up to 800 MeV. As the voltage across the devices was raised all of them failed eventually, even if there was a 1 MOhm resistor in series. With the high-energy carbon ions it could be shown that the failure can be triggered at locations that are hundreds of microns away from the pn-junction. The neutron experiment indicates that there may be a steep fall-off in failure rate at the lowest voltages.