transmission electron microscopes are being utilized more often in failure analysis labs as processing nodes decrease and alternative device structures , such as three dimensional , multi - gate transistors , e . g ., finfets , are utilized in ic designs . however , these types of structures may confuse typical tem sample preparation as the resulting lamella may contain multiple potentially faulty structures , making it difficult to identify the actual faulty structure . passive voltage contrast may be used in a dual beam focused ion beam microscope system including a scanning electron microscope column by systematically identifying non - faulty structures and milling them from the lamella until the faulty structure is identified .