Impact ionization fronts in Si diodes: Numerical evidence of superfast propagation due to nonlocalized preionization

Abstract

We present numerical evidence of a novel propagation mode for superfast impact ionization fronts in high-voltage Si $p^{+}$-$n$-$n^{+}$ structures. In nonlinear dynamics terms, this mode corresponds to a pulled front propagating into an unstable state in the regime of nonlocalized initial conditions. Before the front starts to travel, field-ehanced emission of electrons from deep-level impurities preionizes initially depleted $n$ base creating spatially nonuniform free carriers profile. Impact ionization takes place in the whole high-field region. We find two ionizing fronts that propagate in opposite directions with velocities up to 10 times higher than the saturated drift velocity.

3 pages, 4 figures

References in corpus (4)

• Front propagation into unstable states
• Theory of superfast fronts of impact ionization in semiconductor structures
• Dynamic avalanche breakdown of a p-n junction: deterministic triggering of a plane streamer front
• Impact ionization fronts in semiconductors: superfast propagation due to "nonlocalized" preionization