Transmission imaging on a scintillator in a scanning electron microscope

Area of Science:

• Electron Microscopy
• Materials Science
• Biophysics

Background:

• Conventional electron microscopy (EM) faces throughput limitations for large-area imaging.
• Advances in transmission EM and multi-beam scanning EM (MBSEM) enable large EM datasets.
• Developing efficient imaging techniques for MBSEM is crucial for high-throughput EM.

Purpose of the Study:

• To describe a transmission imaging technique suitable for MBSEM.
• To model and predict contrast-to-noise (CNR) and signal-to-noise (SNR) ratios for this technique.
• To determine the optimal electron landing energy for maximizing imaging performance.

Main Methods:

• A transmission imaging technique using a thin tissue section on a coated scintillator.
• Electrons transmitted through the section generate light, collected by a high NA objective and imaged onto a photon detector.
• Monte Carlo simulations were used to model CNR and SNR, considering parameters like landing energy, staining, section thickness, coating properties, and light collection efficiency.

Main Results:

• Contrast-to-noise ratio (CNR) increases with decreasing landing energy.
• Signal-to-noise ratio (SNR) increases with increasing landing energy.
• An intermediate landing energy optimizes overall imaging performance, dependent on various experimental factors.

Conclusions:

• The developed imaging technique offers a straightforward method for signal separation in MBSEM.
• The study provides a predictive model for CNR and SNR, crucial for optimizing large-area EM.
• Experimental verification on a synthetic sample validates the model's predictions.