Mechanism for excess noise in mixed tunneling and avalanche breakdown of silicon

Abstract

We propose a mechanism to explain the excess noise observed in silicon p-n junctions biased at the onset of mixed tunneling and avalanche breakdown. Electrons tunneling into different conduction valleys are treated as separate reaction channels with different impact ionization rates, due to different initial energies, that contribute excess noise. This noise contribution is regulated by the biasing circuit to prevent runaway. We have analyzed data from past measurements and shown higher conduction valley carrier channels can adequately account for the observed excess noise. The proposed framework provides an explanation of the excess noise data without any fitting parameters.