AstroECP: towards more practical electron channeling contrast imaging

Area of Science:

• Materials Science
• Solid State Physics
• Microscopy

Background:

• Electron channeling contrast imaging (ECCI) is a scanning electron microscope technique for characterizing crystallographic defects in bulk samples.
• ECCI is underutilized for quantitative defect analysis compared to transmission electron microscopy (TEM) methods due to limitations in contrast and beam vector determination.

Purpose of the Study:

• To overcome barriers limiting ECCI's quantitative defect analysis capabilities.
• To optimize signal-to-noise contrast and enable precise incident beam vector determination.
• To introduce a systematic ECCI workflow and open-source software for improved defect imaging.

Main Methods:

• Developed a systematic ECCI workflow incorporating calibrated simulations and experimental selected-area electron channeling patterns (SA-ECPs).
• Introduced the open-source software AstroECP for workflow implementation.
• Utilized dynamical simulations for calibrating stage tilting, SA-ECP field of view, and energy for ECP/ECCI contrast.

Main Results:

• Optimized signal-to-noise contrast and precise incident beam vector determination were achieved.
• Demonstrated the workflow's functionality with case studies, including threading dislocations in GaAs.
• Validated precession-based ECCI contrast (electron channeling orientation determination).

Conclusions:

• The developed workflow and AstroECP software significantly enhance ECCI for quantitative defect analysis.
• Provides best-practice guidelines for implementing ECCI to promote high-resolution defect imaging.
• Facilitates broader adoption of ECCI for bulk-sample crystallographic defect characterization.