A Case Study of a Short Failure Analysis by Voltage Applied EBAC

摘要

Miniaturization scaling of technology node is advancing in recent years, we are almost facing to the age of mass production for ultra-fine devices with the design rule of one-digit nanometers. Along with the scaling of technology node, distance of neighboring wires or contact plugs is inevitably reduced, and so, occurrences of short circuit defect are increasing. So far, various methods had been applied for investigating short-circuit failures. The failure analysis by SEM based electron beam absorbed current (EBAC) technique recently becomes main-stream technique among them because of its spatial resolution to determine the failure position. The DI EBAC that is the EBAC observation acquired by applying some voltage to the failure short circuit and forcing to run bias current through it was known to be effective to fix the malfunction position of failure short circuit. However, it is necessary for making the evaluation condition of the DI EBAC to have the best results. Especially, malfunction area localization for low resistive short failure is difficult by conventional technique, thus, the focus point of measurement condition is to find out DI EBAC short failure localization ability for low resistive short failure mode. In this study, several samples and measuring parameters were evaluated to find the most effective conditions in the DI EBAC. We confirmed that suitable measurement condition was possible to obtain hotspot signals in actual short failure analyses as low resistive shorted failure sample.