Three case studies in which the passive voltage contrast technique (PVC) was used in-fab during the development of a 0.25mm ASIC CMOS technology for rapid characterization and failure isolation are presented. The first case involved using the PVC technique to evaluate the gate oxide quality at different points of the process, allowing for quick identification of the process steps that were damaging the gate oxide and the relative magnitude of the damage that each process step contributed. PVC was then used to perform in-line evaluation of the split lots that were ran to address the problem without having to pull wafers off the line for electrical testing. In the second case study, PVC was used in-line to identify the source of siliciderelated gate-to-source/drain leakage. At this point of the process, electrical probing was not possible, and PVC circumvented this problem. The third case involved using PVC to help identify a new failure mechanism for tungsten plug vias that manifested itself due to plasma charging and layout peculiarities related to deep submicron design rules.