Basic principles of scanning electron microscope
The electron beam emitted by the scanning electron microscope electron gun is focused and condensed into a point light source; the point light source forms a high-energy electron beam under an accelerating voltage; the high-energy electron beam is focused into a light spot with a small diameter through two electromagnetic lenses, and passes through the last one After an electromagnetic lens with a scanning coil, the electron beam bombards the sample surface point by point in a raster-like scanning manner, and at the same time excites electronic signals of different depths.