Scanning Electron Microscope
SEM is one type of electron microscope. It is used for observing a physical object by irradiating an electron beam (a narrow, focused stream of electrons) onto the object by detecting, for example, "secondary electrons" emitted from the object and "reflected electrons" emitted when the direction of travel of the irradiating electron beam travelling within the object varies. Featuring the capability of visualizing the three-dimensional structure of the surface of objects at high sensitivity, SEM is utilized for inspection of the quality of semiconductor components (which are constantly being refined).
