Influence of post-stress effects on the dynamic hot-carrier degradation behavior of passivated n-channel MOSFET´s

An apparently non-quasi-static degradation behavior is found for nMOS transistors that are dynamically stressed with conditions which favor hot-hole injection. This effect can be ascribed to a post-stress effect occurring during the waiting time between the different pulses. It is shown that this effect is of importance only when a net positive charge is built up during the stress. The deviating behavior under dynamic stress conditions can be predicted based on the measurement of the post-stress effect after a static degradation.<>