SEM
A scanning electron microscope (SEM) is a type of electron microscope that images a sample by scanning it with a bundled, fine-focused high-energy beam of electrons in a raster scan pattern. The electrons interact with the atoms that make up the sample producing signals that contain information about the sample's surface topography, composition, and other properties such as electrical conductivity. The information gathered can be displayed as an image. A SEM has a very good depth of focus at very high magnification. With an additional EDX detector, elements can also be determined. It is frequently applied in failure- and element analysis.