Measurement and analysis of hot-carrier-stress effect on NMOSFET's using substrate current characterization

Short-channel NMOSFET degradation is explored by measuring the effect of hot-carrier stress on the substrate and drain currents, with normal and reverse polarities applied. The degradation mechanism can be explained as being, under most conditions, the trapping of electrons in the gate oxide near the stressed drain. This mechanism can explain results which have previously been attributed to trapped holes in the oxide. Two-dimensional simulation of the device characteristics, with the degradation modeled as localized electrons in the oxide, supports this conclusion.