ESD effects on the radiation response of low power vertical DMOS N-channel transistors

Abstract

The effect of non-catastrophic human body model positive electrostatic discharge pulses on the radiation response of low power VDMOS N-channel transistors is explored. The effect of multiple pulses of HBM ESD is to cause a change in threshold-voltage shifts between stressed and non-stressed devices when exposed to Co₆₀ gamma radiation. This difference is due to the build-up of a space charge region next to the Si/SiO₂ interface. This space charge region reduces the net electric field across the gate oxide when biased with a positive voltage and thus reduces the formation of holes and interface traps. Therefore, the ESD stressed devices appear to be less sensitive to radiation.