Quantitative analysis of backscattered-electron contrast in scanning electron microscopy.

Area of Science:

• Materials Science
• Physics
• Chemistry

Background:

• Backscattered-electron scanning electron microscopy (BSE-SEM) is crucial for assessing material homogeneity.
• Quantitative analysis of BSE-SEM images for chemical information remains a significant challenge.
• Relating BSE intensity to backscattering coefficient and atomic number is key for chemical analysis.

Purpose of the Study:

• To develop a quantitative BSE-SEM method for deriving chemical information from images.
• To validate the method using challenging multilayered material systems.
• To demonstrate the utility of Monte Carlo simulations in quantitative BSE-SEM analysis.

Main Methods:

• Comparison of Monte Carlo (MC) simulated and measured BSE intensities.
• Utilizing wedge-shaped electron-transparent specimens with known thickness profiles.
• Implementing measures to enhance and validate MC simulation agreement with experimental data.

Main Results:

• Successfully applied the quantitative BSE-SEM method to ZnS/Zn(OxS1-x)/ZnO/Si and PTB7/PC71BM multilayer systems.
• Demonstrated the validity of the proposed method for quantitative materials analysis.
• Highlighted the importance of realistic MC simulations for accurate BSE-SEM data.

Conclusions:

• The developed quantitative BSE-SEM method enables accurate chemical information retrieval.
• MC simulations are essential for optimizing imaging parameters and improving quantitative analysis.
• Optimized BSE-SEM can distinguish materials with subtle compositional variations.