Burst Noise and Walkout in Degraded Silicon Devices

Two effects, burst noise and walkout, that often accompany soft breakdown in silicon devices are discussed in this paper. It is shown that these effects are present in some devices as soon as they are manufactured and that these effects can be induced in other devices by high temperature storage or by the prolonged passage of large forward currents. The two effects are described and models of the mechanisms are presented. The models assume that both effects originate at the silicon-oxide to silicon interface and result from a stress-induced n+ accumulation layer at the surface of the n silicon.