The concept of advanced metrology is not new to the semiconductor industry. However, the focus of attention always seems to be on increasing the capabilities of visual inspection for defects even though yield-affecting defects include non-visible electrical defects, parametric defects and electrical faults whose root cause is often difficult to determine. The "2001 SIA International Roadmap for Semiconductors: Yield Enhancement" notes that current Data Management Systems (DMS) have limited abilities to incorporate real-time in-situ sensor data that can be correlated with lot and wafer-based data. Further, current DMS are even more limited in their abilities to use the information in a yield-predictive way in spite of the fact that real-time analysis of such data would result in more rapid identification and prioritization of defect generating mechanisms to a broad sector of engineering group. In this presentation, the sensor-integration and analysis system, FabGuardâ, is used to address these shortcomings by combining sensor output with logic and signal analysis to create real-time in-situ metrics for wafer health. These can then be used to track potential non-visible yield-loss defects in a way that can drive continuous product improvement with decreased emphasis on in-line and ex-situ metrology. The use of residual gas analysis in monitoring the degas operation in PVD cluster tools is shown to be a capable for generating metrics that sensitive to process variations exhibited by prior processing equipment such as etch, ash and CVD. Case studies of applying this metrology are presented that identify root causes of contamination-induced yield-limiting defect mechanisms.