AstroECP: towards more practical electron channeling contrast imaging

Electron channeling contrast imaging (ECCI) is a scanning electron microscope based technique which enables bulk-sample characterization of crystallographic defects (e.g. dislocations, stacking faults, low-angle boundaries). Despite its potential, ECCI remains underused for quantitative defect analysis as compared with transmission electron microscope based methods. Here, we overcome barriers that limit the use of ECCI by optimizing signal-to-noise contrast and precise determination of the incident beam vector using calibrated, easy-to-use simulations and experimental selected-area electron channeling patterns (SA-ECPs). We introduce a systematic ECCI workflow, alongside a new open-source software tool (AstroECP), which includes calibration of stage tilting, SA-ECP field of view and the energy that forms the ECP/ECCI contrast using dynamical simulations. The functionality of this workflow is demonstrated with case studies that include threading dislocations in GaAs and the cross-validation of precession-based ECCI contrast, which is otherwise known as electron channeling orientation determination. To assist the reader, we also provide best-practice guidelines for ECCI implementation to promote high-resolution defect imaging in the scanning electron microscope.