Problems in semiconductors and integrated circuits range from crystalline defects to contamination to misformed structures. They may be due to a single event (e.g. foreign particle) or a complex interaction between materials, processes, and environment. Many clues for the cause of these problems can be obtained from in-line measurements, such as electrical device behavior or layer thickness, but it is often not until after a defect or abnormal structure is seen that it is fully understood. The method of “seeing” must allow the normal to be distinguished from the abnormal and ultimately the reason for the difference to be determined. Vast amounts of data are often generated to electrically understand a defect or determine the reliability implications of a problem but it is often not until microscopic analysis is performed that the problem is fully revealed. It is not uncommon for just a small number of images bring to light the origin of a problem and lead to a solution.