Failure Localization of Bipolar Integrated Circuits by Implementing Active Voltage Contrast

Bipolar ICs are playing an important role in military applications, mainly used in logic gates, such as inverter and NAND gate. A metal break defect located on the step is one of the main failure mechanisms of bipolar ICs, resulting in open-circuit or functional failure. In this situation, general failure localization methods like optical beam induced resistance change (OBIRCH) and photon emission microscopy (PEM) might not be fully effective. However, active voltage contrast (AVC) can be used as a voltage probe, which may pinpoint the incorrect potential and thus locate the failure position. Two case studies will be present in this paper on how to implement AVC for failure localization, and the detailed failure mechanism will be discussed.