Mobility degradation due to interface traps in plasma oxynitride PMOS devices

Mobility degradation due to generation of interface traps (Deltamu_eff(N_IT)) is a well-known phenomenon that has been theoretically interpreted by several mobility models. Based on these analysis, there is a general perception that Deltamu_eff(N_IT) is relatively insignificant (compared to Deltamu_eff due to ionized impurity) and as such can be safely ignored for performance and reliability analysis. Here, we investigate the importance of considering Deltamu_eff(N_IT) for reliability analysis by analyzing a wide variety of plasma oxynitride PMOS devices using both parametric and physical mobility models. We find that contrary to popular belief this correction is fundamentally important for robust and uncorrupted estimates of the key reliability parameters like threshold-voltage shift, lifetime projection, voltage acceleration factor, etc. Therefore, in this paper, we develop a generalized algorithm for estimating Deltamu_eff(N_IT) for plasma oxynitride PMOS devices and systematically explore its implications for NBTI-specific reliability analysis.