Experimental data and model simulations of beam spread in the environmental scanning electron microscope

Area of Science:

• Physics
• Materials Science
• Microscopy

Background:

• Electron beam spreading in environmental scanning electron microscopy (ESEM) arises from electron scattering by gas molecules.
• This scattering creates an electron 'skirt' around the primary beam, affecting image resolution.
• Factors influencing skirt intensity include gas pressure, beam path length, beam energy, and gas composition.

Purpose of the Study:

• To compare experimental measurements of electron beam spread with predictions from an independently developed model.
• To validate the model's ability to describe electron scattering phenomena in ESEM.

Main Methods:

• Experimental measurements of electron beam skirt intensity were conducted under controlled ESEM conditions.
• A theoretical model was used to predict the radial intensity distribution of scattered electrons.
• Direct comparison between experimental data and model predictions.

Main Results:

• The developed model successfully predicts the general trends observed in experimental electron beam scattering intensities.
• A systematic deviation was observed between the model's predictions and the experimental measurements.
• The model's accuracy in predicting beam skirt intensity requires further refinement.

Conclusions:

• The model provides a valuable framework for understanding electron beam spread in ESEM.
• Further development is needed to reconcile model predictions with experimental observations for improved accuracy.
• Accurate modeling of beam spread is crucial for optimizing ESEM performance and data interpretation.