Components of the SEM

Abstract

The primary components of the SEM are electron column, specimen chamber, and computer control system as shown in the photograph of Fig. 2.1. These components are used to carry out various functions of microscopy and microchemical analysis. The SEM instrumentation may include secondary and backscattered electron detectors, energy-dispersive x-ray spectrometer (EDS), low vacuum detector, electron backscattered diffraction (EBSD) detector, etc. Some of this instrumentation may not be necessary for basic imaging but play an increasingly important role in more demanding microscopy applications. A user has a continual interaction with the primary components of the SEM, which has a direct bearing on the quality of images and analyses obtained. In addition to these components, secondary/miscellaneous equipment such as vacuum pumps, water chiller, and electronics form an essential part of the overall system without which the SEM cannot function. However, this equipment runs seamlessly in the background and hardly needs any input from the user. Modern day SEMs are controlled with computers. However, the quality of images obtained largely depends on the input parameters as determined by the operator. This necessitates the study of SEM and its various components and the way it can be used to produce high-quality images and reliable analytical data.