Failure Analysis Methodology on Circular Patch Functional Failure Due to Device Parametric Drift

This paper describes the debug and analysis process of a challenging case study from wafer foundry which involved a circular patch functional leakage failure that was induced from device parametric drift due to thicker gate oxide with no detection signal from inline monitoring vehicles. It highlights the need for failure analyst to always be inquisitive and to deep dive into the failure symptoms to value-add the fab in discovering the root cause of the failure in challenging situation where information is limited.