The properties, effect and extraction of localized defect profiles from degraded FET characteristics

We report simulations of localized defect profiles (DPs), typical for hot-carrier degradation (HCD), with exponential- and step-like shapes. First, we analyze how these localized DPs affect the transistor I-V and model the complex relation between DP and FET degradation by considering the degraded FET as a series circuit of an undegraded transistor (the source side) and a degraded one (the drain side). We also compare how the same DP causes different degradation for changes in the device structure. Second, we use the DP simulations to qualitatively understand the DP dependence on stress voltages in measured FETs and assess how uniquely a DP can be extracted from degraded I-V metrics. The results are of interest for HCD modeling.