AstroECP : towards more practical electron channeling contrast imaging

Journal of Applied Crystallography, vol. 59, pp. 530–551

Abstract

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.

Authors 8

1. M. Haroon Qaiser

   University of British Columbia

   Affiliation as printed

   Department of Materials Engineering University of British Columbia Vancouver British Columbia Canada

2. Lukas Berners Aachen Institute of Physical Metallurgy and Materials Physics

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Metallurgy and Materials Physics RWTH Aachen University Germany

3. Robin J. Scales

   University of Oxford

   Affiliation as printed

   Department of Materials University of Oxford Oxford Oxfordshire United Kingdom

4. Tianbi Zhang

   University of British Columbia

   Affiliation as printed

   Department of Materials Engineering University of British Columbia Vancouver British Columbia Canada

5. Martin Heller Aachen Institute of Physical Metallurgy and Materials Physics

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Metallurgy and Materials Physics RWTH Aachen University Germany

6. Jiří Dluhoš

   Tescan (Czechia)

   Affiliation as printed

   TESCAN Group a.s., Libušina třída 21, Brno, Czech Republic

7. Sandra Korte‐Kerzel Aachen Institute of Physical Metallurgy and Materials Physics

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Metallurgy and Materials Physics RWTH Aachen University Germany

8. T. Ben Britton

   University of British Columbia

   Affiliation as printed

   Department of Materials Engineering University of British Columbia Vancouver British Columbia Canada