Conventional sample preparation methods can introduce mechanical stresses, smearing, and thermal artifacts that alter the pristine microstructure of specimens, potentially compromising subsequent analyses [1]. To address these limitations, we investigate ultrashort femtosecond laser-based sample preparation as a minimally invasive alternative, complemented by focused ion beam (FIB) polishing, for specimens intended for SEM characterization [2].

Femtosecond laser pulses enable athermal bulk material removal, achieving rapid and precise ablation while minimizing thermal effects and excluding mechanical stress. This approach preserves critical microstructural features, such as interfaces, inclusions, and fine structural details, maintaining the specimen’s intrinsic state. Following laser ablation, FIB polishing provides delicate surface refinement, producing surfaces suitable for high-resolution SEM imaging, with minimal preparation-induced artifacts [2, 3].

Laser parameters—including pulse energy, repetition rate, and scanning strategy—were systematically optimized for different specimen types to maximize surface quality and reproducibility. CAD-based navigation allows targeted preparation of regions of interest, enhancing efficiency and consistency across multiple samples. A comparative evaluation with conventional mechanical preparation demonstrates that the laser-FIB workflow substantially reduces preparation-induced stress and artifacts, thereby improving microstructural fidelity and analytical reliability.

In summary, ultrashort pulse laser-based preparation, complemented by FIB polishing, represents a high-precision, minimally invasive alternative to conventional mechanical preparation. By reducing mechanical stress and preserving intrinsic microstructural features, this workflow enhances the accuracy and reliability of SEM- and EBSD-based analysis, providing a pathway for artifact-free investigation across a broad range of materials.

References

[1] N.D. Bassim, B.T. De Gregorio, A.L.D. Kilcoyne, K. Scott, T. Chou, S. Wirick, et al., Minimizing damage during FIB sample preparation of soft materials, J. Microsc. 245 (2012) 288-301.

[2] P. Denninger, P. Schweizer, E. Spiecker, Characterization of extended defects in 2D materials using aperture-based dark-field STEM in SEM, Micron 186 (2024) 103703.

[3] T. Höche, M. Krause, M. Ebert, U. Wagner, A Novel Laser Tool for High-Volume Sample Preparation, Laser Technik Journal 1/2015, 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.