Scanning electron microscope (SEM)


A microscope that scans the specimen with an electron beam, measures the intensity of quantum emitted from specimen, such as secondary electrons, reflected electrons and so on, to convert into electric signals. It can draw an image of distribution of a property of the material.

Since no electromagnetic lens is used in the image forming system, resolution of a SEM is determined by the diameter of the incident electron beam. By changing the quantum to detect, status of various properties can be observed. For example, observation of status of secondary electrons provides the images of the surface structure, and distribution of electric potentials of the specimen. Images of reflected electrons disclose composition and crystalline conditions. The X-rays image shows distribution of elements.


[Related Terms]
Transmission electron microscope (TEM)