Quasi-ray Tracing Method for Coulomb Interaction Estimation in Charged Particle Systems.

Area of Science:

• Physics
• Materials Science
• Engineering

Background:

• Coulomb interaction (CI) significantly degrades resolution in charged particle imaging systems.
• High probe currents in scanning electron microscopes (SEM) amplify CI-induced resolution loss.
• Existing CI estimation methods lack a balance between speed and accuracy, hindering SEM design optimization.

Purpose of the Study:

• To develop a novel, efficient, and accurate method for estimating Coulomb interaction (CI) in charged particle imaging.
• To overcome the speed and accuracy limitations of current CI estimation techniques.
• To facilitate the optimization of SEM design parameters through improved CI analysis.

Main Methods:

• Proposed a quasi-ray tracing method leveraging perturbation theory.
• Employed Monte Carlo ray tracing to simulate CI-induced trajectory displacement and the Boersch effect.
• Eliminated the need for iterative solvers found in conventional direct ray tracing.

Main Results:

• Achieved simulation speeds over 105 times faster than direct ray tracing.
• Demonstrated an error margin of less than 1% compared to direct ray tracing.
• Validated performance across a wide range of parameters relevant to SEM applications.

Conclusions:

• The quasi-ray tracing method provides a fast and accurate solution for CI estimation.
• This approach significantly enhances the efficiency of optimizing charged particle imaging systems.
• Offers a generalizable tool for addressing CI effects in various electron microscopy applications.