Guide to Coating for SEM Imaging

Imaging non-conductive samples in scanning electron microscopy (SEM) can be challenging. When exposed to the electron beam, non-conductive samples accumulate electrostatic charge, which can result in image distortions, defocussing, or bright spots on the SEM image. To prevent charge accumulation, techniques such as coating with a thin conductive layer, variable pressure SEM, low-kV imaging, beam deceleration, and environmental SEM (ESEM) can be employed.