Advanced analytical tools that have been primarily used for research and development application in the past are now being used extensively to understand VLSI failure analysis and reliability problems. In this paper, we present several new applications and techniques in the use of scanning electron microscopy (SEM), transmission electron microscopy (TEM). focused ion beam (FIB) microsurgery and secondary ion mass spectroscopy (SIMS) for problem solving. These tools, used in new ways. are playing a key role in identifying the sources of defects leading to potential device reliability problems and contributing to the elimination of their sources in the process line.