A Common Framework of NBTI Generation and Recovery in Plasma-Nitrided SiON p-MOSFETs

Generation and recovery of degradation during and after negative bias temperature instability (NBTI) stress are studied in a wide variety of plasma-nitrided (PN) silicon oxynitride (SiON) p-MOSFETs. An ultrafast on-the-fly linear drain current (I_DLIN) technique, which is capable of measuring the shift in threshold voltage from very short (approximately in microseconds) to long (approximately in hours) stress/recovery time, is used. The mechanics of NBTI generation and recovery are shown to be strongly correlated and can be consistently explained using the framework of an uncorrelated sum of a fast and weakly temperature (T)-dependent trapped-hole (??V _h) component and a relatively slow and strongly T-activated interface trap (??V _IT) component. The SiON process dependences are attributed to the difference in the relative contributions of ??V _h and ??V _IT to the overall degradation (??V _T), as dictated by the nitrogen (N) content and thickness of the gate insulator.