Cosmic ray-induced DC-stability failure in Si diodes

A tandem accelerator has been used to simulate the effect of cosmic rays on the DC stability properties of a reverse biased pn diode. 30 MeV Carbon ions, with a maximum ionization of 130 eV//spl Aring/, were stopped in a reverse biased pn-junction. If the electric field is high enough, the large number of electron-hole pairs created by the ions results in the initiation of an avalanche. The current was limited to prevent a complete breakdown, and the diodes could be used repeatedly. The dependence of the field for the occurrence of the sudden avalanches was exponential, which has previously been reported for cosmic ray failures. Computer simulation showed that inductive or capacitive loads are necessary to initiate the avalanche.