A new type of scanning electron microscope using the coaxial backscattered electrons

Area of Science:

• Materials Science
• Analytical Chemistry
• Physics

Background:

• Conventional Scanning Electron Microscopy (SEM) often faces challenges in simultaneously visualizing atomic-number and topographic contrast.
• Distinguishing between elemental composition and surface morphology can be difficult with standard SEM imaging techniques.

Purpose of the Study:

• To introduce and evaluate a new coaxial detection system for backscattered electrons in SEM.
• To enhance atomic-number contrast while suppressing topographic contrast for improved material analysis.
• To develop a method for combining chemical and topographic information into a single, composite image.

Main Methods:

• Development of a coaxial detection system designed to collect backscattered electrons with minimal energy loss.
• Utilizing a specific take-off angle defined by the objective lens for electron collection.
• Conducting simulations and experimental validation of the new SEM configuration.

Main Results:

• The coaxial detection system significantly reinforces atomic-number contrast in SEM images.
• Topographic contrast is effectively suppressed, allowing for clearer visualization of compositional differences.
• Experimental results confirm the system's suitability for observing atomic number variations.
• A novel color imaging technique combining secondary electron and backscattered electron data provides simultaneous chemical and topographic information.

Conclusions:

• The new coaxial detection system offers a significant advancement in SEM capabilities for materials characterization.
• This technology enables more precise differentiation of elements based on atomic number.
• The integrated color imaging approach provides a comprehensive view of sample composition and surface structure in a single image.