Depth Resolution Dependence on Sample Thickness and Incident Energy in On-Axis Transmission Kikuchi Diffraction in...

Area of Science:

• Materials Science
• Nanotechnology
• Crystallography

Background:

• Transmission Kikuchi diffraction (TKD) is an advanced microscopy technique.
• It provides high-resolution orientation maps of material microstructures.
• Understanding its depth resolution is crucial for nanoscale analysis.

Purpose of the Study:

• To experimentally determine the depth resolution of the on-axis TKD configuration.
• To investigate the influence of incident electron energy and sample thickness on depth resolution.
• To develop a predictive model for TKD depth resolution.

Main Methods:

• Utilized a custom-designed twinned silicon bi-crystal sample.
• Performed Transmission Kikuchi diffraction experiments across a range of incident electron energies (10-30 keV).
• Analyzed the relationship between measured depth resolution, incident energy, and sample thickness.

Main Results:

• Depth resolution was measured to be between 30 and 65 nm.
• A near-linear dependence of depth resolution on incident energy was observed.
• Depth resolution showed no dependency on the total sample thickness.

Conclusions:

• Depth resolution in TKD is governed by Kikuchi diffraction generation and subsequent absorption.
• A model based on electron mean free path accurately predicts the energy dependence of depth resolution.
• The mean absorption coefficient can predict TKD depth resolution across different materials and energies.