Fault Isolation for a Nanometer-Scale Poly Protrusion Causing Single Column Failure in SRAM Device

A common failure mode such as a faulty single full column in an SRAM can be caused by a wide range of defect types at various locations. Fault isolation by thorough electrical analysis and circuit behavior understanding is needed to precisely pinpoint the defect minimizing the destructive physical analysis. This case study shows the process and the techniques used to identify a nanometer scale poly defect.