Site-specific femtosecond laser ablation: The pathway to high-throughput atom probe tomography characterization

The exceptional chemical detection sensitivity and near-atomic scale resolution made atom probe tomography (APT) to an indispensable analytical tool to investigate the 3D chemical nature of crystal defects. However, this makes site-specific APT tip preparation necessary and, a long-lasting challenge obvious. The current gold standard for site-specific APT tip preparation using focused ion beams (FIB) is very time and resource consuming. The likely premature tip fracture of the welding zone between tip and specimen carrier further decreases the success rate. Facing these challenges, APT data sets are rarely of statistically relevant size as mostly only one or few sites (e.g., single grain boundary) are analyzed at best. Here we tackle these issues by successfully implementing femtosecond laser ablation to site-specifically prepare APT tips directly into the specimen, rendering lift-out procedures unnecessary. Our approach drastically reduces preparation time, as before near-net shaping of the APT tips with the laser, only the features of interest have to be marked. The time for the tip ablation process further does not require personal assistance and is independent of the number of tips. Moreover, FIB time is reduced to a final gentle tip sharpening process. The approach is extremely robust, as demonstrated by successful tip preparation of 100 % of the targeted features, including final analysis using field ion microscopy and APT. Thus, site-specific femtosecond laser ablation has the potential to develop APT towards a high-throughput characterization method. • Site-specifically prepare near-net shape APT tips using femtosecond laser ablation. • Only final tip sharpening by FIB is necessary. • Welding of tips to commercial coupons is not necessary. • 100 % of the targeted features could be successfully prepared. • Overall time efficiency is significantly increased.