Multiple-Beam Scanning Electron Microscopy

When resolving structures at nanometer scale, electron microscopes are the tools of choice. Since the invention of the electron microscope, the technology has matured into a standard technique applied in a wide variety of disciplines and laboratories. This holds especially true for scanning electron microscopes (SEMs), which have developed from room-filling equipment operated by highly specialized scientists to automated, desktop-sized, or even mobile, tools [1]. Some of the major advancements of SEMs in recent years have been (a) increases in resolution, especially at low electron landing energies [2]; (b) improvements in usability through digitalization, advances in software and tool handling, or miniaturization [3]; (c) addition of improved detection schemes such as energy- or wavelength-dispersive X-ray spectrometry (EDX, WDX) to maximize the amount of information that can be taken from the sample [4]; and (d) combinations of electron microscopy with other microscopic techniques for correlative microscopy [5–9]. SEMs have become ubiquitous tools that are used in various environments and for many different applications; they no longer require highly specialized operators. For many SEM applications in practice, the highest achievable resolution is not required [10].