Speakers
Description
Łukasz Feldo-Grudziński BSc, Daniel Wójcik MSc
1. Introduction to Scanning Electron Microscopy (SEM)
Overview of SEM Technology: Historical development, evolution from optical to electron microscopy, and modern applications in materials science, geology, biology, and engineering. SEM Instrumentation Components: Electron gun types (thermionic, field emission), electromagnetic lenses, apertures, scan coils, detectors, and vacuum systems. Electron–Matter Interactions: Primary and secondary electron production, backscattered electrons, X-rays, and other signals generated by electron beamsample interaction. Imaging Modes and Contrast Mechanisms: Secondary electron imaging for topography and backscattered electron imaging for compositional contrast.
2. Principles and Mechanism of SEM Operation
Electron Beam Generation: Mechanisms of electron emission and control of beam parameters (current, spot size, energy).
Beam–Sample Interaction Volume: Depth and lateral extent of interaction, dependence on accelerating voltage and atomic number.
Signal Detection and Image Formation:
• Secondary electron detector (Everhart-Thornley) for surface morphology.
• Backscattered electron detector for atomic number contrast.
• Other detectors: in beam detectors, transmitted electron detectors and EBSD systems. Image Resolution and Artifacts:
Factors affecting resolution (probe diameter, working distance, astigmatism), and common image artefacts with troubleshooting approaches.