Hydrogen Passivation of Boron Acceptors and Long-Term Breakdown Voltage Instability in N/sup +//P Su

The breakdown voltage of integrated N+/P surface avalanche diodes has been observed to drift up to 40% of the initial value after 20'000 hours of field operation. The magnitude and the paroxistic behaviour of such a degradation could not be supported by the traditional walk-out effects. The present paper explains the observed instability in terms of the passivation of boron acceptors by hydrogen atoms introduced during the deposition of the silicon nitride glassivation. Finally, it reports the main symptoms and shows the proper techniques for the detection of this failure mechanism.