AVALANCHE SHOCK FRONTS IN <i>p-n</i> JUNCTIONS

Abstract

A new transient mode of avalanche breakdown in p-n junctions is described. For sufficiently high current, a region of impact ionization of carriers advances as a shock front whose velocity can be several times faster than the carrier-saturated drift velocity. Since the passing disturbance rapidly fills the depletion region with a dense plasma of holes and electrons, it has been used to interpret the observed high-efficiency microwave oscillations of the trapped-plasma ``TRAPATT'' mode. An approximate analysis is given, and compared with numerical calculations.