Scanning Electron Microscopy (SEM) provides high-resolution imaging useful for evaluating various materials for surface fractures, flaws, contaminants, or corrosion. It is often used in metallurgy, semiconductors, nanomaterials, energy storage, medical devices, biotech, green energy, microelectronics, and other application areas.
SEM allows researchers to image and investigate micro- and nano-structures in solid objects using a focused beam of electrons to probe the surface layers. This technique helps characterize topography, morphology, and material composition, which can be applied to detect contamination, understand structural artifacts, and much more. SEM produced three types of signals; each provides different types of information. Understanding these signal types is vital in designing and conducting SEM experiments.
The eBrief, The 3 SEM Signals You Need to Know to Optimize Your SEM Analysis, provides an overview of these signal types. The eBrief covers how backscattering electrons (BSE), secondary electrons (SE), and x-ray emissions originate, what each signal is best used for, and tips on refining an experiment to optimize your data. Understanding the needs of the desired research and the type of signals needed to best probe the samples can lead to easier decisions in designing the experiment, such as which detector to use, how high the voltage should be, or if an electric field is needed.
In a cutting-edge SEM instrument, such as the Helios 5 DualBeam or Scios DualBeam, a wide selection of detectors and instrument settings are available, all of which can alter the results. While this selection can often be intimidating, understanding the desired results and the necessary signal can help narrow these choices down. With the right signal in mind, we can solidify our choices for detectors and narrow down the rest of the instrument settings to optimize this signal type. If you are designing an SEM experiment and are looking for a place to start, understanding the signal types can be a great place that will help refine the rest of the process.
To better understand SEM signals and how to refine your SEM experiments, check out the eBrief and learn more about these three types of signals and a few ways to optimize your experiments to reach your research goals.