Thermal instability in p-channel transistors with reoxidized nitrided oxide gate dielectrics

Abstract

The authors report p-channel transistor degradation at elevated temperatures due to negative bias temperature instability (NBTI) combined with high-temperature hot-carrier degradation in devices with reoxidized nitrided oxide (RNO) gate dielectrics. It is shown that the degradation is considerably more severe than in devices with oxide gate dielectrics. At temperatures below 150 degrees C and voltages below 6 V, the RNO degradation under NBTI and combined NBTI/hot-carrier stress conditions is roughly an order of magnitude worse than the oxide degradation. Compared to the NBTI stress alone, the combined effect of hot-carrier and NBTI stress is to increase the degradation of both RNO and oxide devices by an additional two orders of magnitude. The results obtained are particularly significant for the determination of appropriate burn-in conditions for integrated circuits.