The junction ideality factor for ageing characterization

A new method to investigate hot carrier degradation in submicrometer n-MOS transistors is presented. An alteration of the current-voltage characteristics of the substrate-drain junction has been observed after electrical constraints. Junction parameters are extracted and their variations after ageing steps are used to characterize the degradation of the device. Degradation processes by injected carriers are related to the insulating oxide edge defects in the gate to drain overlap region. The junction ideality factor appears as a sensitive parameter usable to characterize ageing effects and to quantify the magnitude of the degradations.