Active doping instability in n+- p silicon surface avalanche diodes

Abstract

A failure mode of n +- p silicon surface avalanche diodes subject to reverse current stress is characterized. The observed instability of the breakdown voltage is associated with a large increase of the dynamic resistance of the diode, likely due to boron neutralization of the p-type silicon region by hydrogen atoms released by hot-carriers from the avalanche condition. The initial phase of degradation is described by an empirical equation with appropriate parameters valid for a wide range of temperature and reverse current. Both static and dynamic degradation is investigated. Some issues relevant to accelerated life-tests are also addressed.