This article describes a series of experiments that were conducted on flash memory devices to correlate the defects that are detected by photon emission microscopy (PEM) and laser-induced techniques. Currently, there are two main categories of fault localization techniques for failure analysis, namely passive and active techniques. The article discusses defect localization by PEM and SOM. Three types of defects are described: Type 1 defects are those that can be accurately localized by both PEM and laser-induced techniques; Type 2 defects are defects which can only be detected with PEM and are not observable with laser-induced techniques; and Type 3 defects are those that are detectable with laser-induced techniques but cannot be detected by PEM. While PEM is able to capture the symptoms of existing leakage defects, laser-induced techniques can precisely localize temperature sensitive defects.