As semiconductor technologies continue to decrease in size and the number or metallization layers increase, traditional methods for localizing the failure mechanism in failing semiconductor circuits such as micro-probing or light emission are severely limited if not impossible to perform. In response to this situation, nano-probe technologies have been developed to overcome this obstacle. In this tutorial, both AFM based and in-situ beam tool based (FIB/SEM) nano-probe technologies will be reviewed. Techniques for the characterization and identification of common semiconductor defects will be presented. Case studies for several types of defects will also be presented.