Uncovered the “hidden real defect” masked by “other anomaly seen” through deep dive FA in wafer fabrication

In wafer fabrication, it is important for analyst to be equipped with the mindset of deep dive towards uncovering the underlying “hidden and real” defect even after finding some anomaly that appears to be the root cause. This is critical as inexperience analyst may regards the 1st anomaly seen as the cause of the low yield issue and this will lead to wrong process fix by the process integration. In this paper, we will discuss on 2 case studies to illustrate the beauty and importance of deep dive FA towards uncover the “hidden real defect” as masked by other anomaly seen first during the analysis. It will illustrate how failure analysis continues from analyst own thought to embark the root cause.