Dynamic avalanche breakdown of a p-n junction: Deterministic triggering of a plane streamer front

Abstract

We discuss the dynamic impact ionization breakdown of a high voltage p-n junction which occurs when the electric field is increased above the threshold of avalanche impact ionization on a time scale smaller than the inverse thermogeneration rate. The avalanche-to-streamer transition characterized by generation of dense electron-hole plasma capable of screening the applied external electric field occurs in such regimes. We argue that the experimentally observed deterministic triggering of the plane streamer front at the electric-field strength above the threshold of avalanche impact ionization, yet below the threshold of band-to-band tunneling, is generally caused by field-enhanced ionization of deep-level centers. We suggest that the process-induced sulfur centers and native defects such as EL2, HB2, and HB5 centers initiate the front in Si and GaAs structures, respectively. In deep-level-free structures the plane streamer front is triggered by Zener band-to-band tunneling.