Optimization and application of Electron Beam Absorbed Current technique

Advanced microprocessors are aggressively scaled with process technology rapidly advancing to 14nm technology node. This presents a challenging task to uncover subtle physical defects resulting from resistive via/contact & shorted tight pitch metal interconnects. Electron Beam Absorbed Current (EBAC) is a promising technique that can help to identify the defective vias or metal shorts in non-invasive manner. This technique is based on scanning electron microscopy (SEM) and pizeo manipulators of tungsten tips. Metal lines are probed with tungsten probes in SEM and electrons beam current absorbed by the metal lines are collected and used to form a current or voltage contrast map of the area. Any abnormal metal EBAC image would indicate metal line defects and can be correlated with layout images.