Application of passive voltage contrast and focused ion beam on failure analysis of metal via defect in wafer fabrication

A case of the application of passive voltage contrast (PVC) and focused ion beam (FIB) to failure analysis of metal interconnection or via defects in wafer fabrication was studied. We have proposed a simple, efficient and cost-saving identification method of locating the 1st, 2nd, 3rd and higher defective vias in the via chain through FIB-induced PVC and its precise cross-sectioning. Such a technique proves useful as it enables us to understand whether all the defective vias in the via chain exhibit the same failure phenomenon or display any particular failure pattern which will help the failure analysis or process engineers to determine the failure mechanism.