Abstract
The work presented here is related to the utilization of computer aided design (CAD) Navigation tools in combination with images from Emission Microscope (EMMI) to improve the accuracy and efficiency of Failure Analysis. The paper presents the flow to quickly identify the failing device by taking the photon emission microscope image and CAD data as input. EMMI is used extensively for detecting leakage current resulting from device defects, e.g., gate oxide defects/ leakage, latch-up, electrostatic discharge (ESD) failure, junction leakage, etc. This emitted light is captured as hotspots on the image. A typical photon emission microscope image has a series of photon emission spots initiated by one physical defect. Not all emission spots may be defects; for example, emissions are shown during normal saturation or switching mode of the transistor. This results in multiple connectivity path between these spots which failure analysis (FA) engineer may want to analyze. The FA engineer wants to detect the one failed device which causes multiple other devices to show false hotspots. The work presented in this paper involves identifying all the devices beneath the hotspot areas, processing the connectivity of the found devices and extracting the schematic for all the devices beneath these hotspots. The connectivity between the devices could be direct connections through nets or indirect through “transmission gates”. The extracted schematic helps the FA engineer focus the FA work on critical devices such as a driver and enables faster and more accurate fault localization. The work in the paper shows the extraction of critical path of devices and their connectivity.
