The BSE (Back Scattered Electron) image contrast differs depending on both the take-off angle and energy of backscattered electrons. This contrast change needs to be visualized as some information may remain hidden when using more conventional BSE detection systems.
The new TESCAN CLARA ultra-high-resolution scanning electron microscope (UHR-SEM), based on TESCAN’s BrightBeamTM technology, enables variable, filtered BSE detection. One of the features of the TESCAN CLARA’s BSE detection system is the electron filtering based on take-off angle which allows users to explore three different contrast mechanisms.
The TESCAN CLARA UHR-SEM is equipped, as standard, with three BSE detectors:
- Fully retractable in-chamber detector collecting the wide-angle electrons. This, wide-angle BSE signal, significantly highlights topographical contrast.
- In Beam Axial detector, collecting the narrow-angle electrons. The take-off trajectories of BSEs collected by the Axial Detector are, of course, close to the optical axis of the SEM column and as a result provide topography-free compositional contrast.
- Multidetector (BSE) collects the so called ‘mid-angle’ backscattered electrons. The unique capability of this detector is that areas which were hidden from the in-chamber BSE detector are now visible here, however, moderate topographical contrast of the sample is also maintained.
This application example presents the benefits of the angular filtration of backscattered electrons.
Fig 1. Images of the natural oxidation of the metal surface collected with different TESCAN CLARA BSE detectors. LE BSE (wide-angle), Multidetector (mid-angle), Axial (narrow-angle) and color-coded image where each angle is represented by a color.
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TESCAN USA Inc.
Founded in 1991 by a group of managers and engineers from Tesla with its electron microscopy history starting in the 1950’s, today TESCAN is a globally renowned supplier of Focused Ion Beam workstations, Scanning Electron Microscopes and Optical Microscopes. TESCAN’s innovative solutions and collaborative nature with its customers have won it a leading position in the world of nano- and microtechnology. The company is proud to participate in premier research projects with prominent institutions across a range of scientific fields. TESCAN provides its clients with leading-class products in terms of value, quality and reliability. TESCAN USA Inc. is the North American arm of TESCAN ORSAY HOLDINGS, a multinational company established by the merger of Czech company TESCAN, a leading global supplier of SEMs and Focused Ion Beam workstations, and the French company ORSAY PHYSICS, a world leader in customized Focused Ion Beam and Electron Beam technology.
This information has been sourced, reviewed and adapted from materials provided by TESCAN.
For more information on this source, please visit Tescan.com.