**2. Historical development**

The human eye's ability to see very small and fine details is limited. For this reason, optical devices have been developed that help to see smaller images and details by changing the light paths that provide the transmission of the image with the help of various lenses. In 1923, De Broglie showed that electrons have wave behavior. In 1926, Busch discovered that electrons are deflected in a magnetic field. In 1935, Max Knoll became the name that produced the first SEM device. The first commercial scanning electron microscope was produced by Siemens in 1965. When Max Knoll manufactured the first Scanning Electron microscope in Berlin in 1935, he did not need a patent because he could not reach high magnifications [1]. In the same period, transmissive electron microscopes (TEM) are being developed, but images with the desired resolution cannot be obtained. With the simultaneous development and use of electronics with optical systems, imaging at high magnifications has become possible. The scanning electron microscope, designed within the framework of electrooptical principles, is one of the devices that serve this purpose. In addition to its use in research and development studies in many branches, SEM is widely used in chip production in microelectronics, error analysis in different branches of industry, biological sciences, medicine and criminal applications [2]. As a result of technological developments, SEM devices with high resolution field emission gun (FEG) have been developed. For this reason, the potential of SEM has emerged.
