Integration of a Broad Argon Ion Beam Into a Scanning Electron Microscope for In-Situ Large-Area Surface Preparation and Analysis.

In-situ, large-area, and high-quality surface preparation is essential for statistically representative microstructure characterization. Focused ion beam (FIB) systems are typically confined to scales below a hundred microns, while standalone broad ion beam (BIB) polishing systems often suffer from surface contamination and repositioning errors during sample transfer. Herein, we report an integrated argon broad ion beam scanning electron microscope (BIB-SEM) system achieved by mounting an electron cyclotron resonance (ECR) ion source directly into the SEM chamber. Three key engineering challenges were addressed through dual-layer magnetic shielding to suppress stray fields from the ECR ion source, a sputter-shielding assembly to mitigate debris contamination, and a wide-range tilt stage enabling flexible polishing angles and EBSD analysis. The integration establishes an iterative polishing-and-characterization workflow, allowing for in-situ assessment and parameter optimization without breaking vacuum. This capability enabled feedback-driven optimization on aluminum alloy to reach 99.98% EBSD indexing rates, uniform surfaces on molybdenum with >98% EBSD indexing rates across multiple regions on a ∼21 mm2 area, statistical analysis of estimated over 8 × 105 NCM811 particle cross-sections, and rapid cleaning of contaminated surface within 5 min. This integrated BIB-SEM system enables in-situ, millimeter-scale surface preparation with SEM/EBSD validation, advancing representative microstructural characterization in materials science.