3D-Micromac AG, Germany, the industry leader in laser micromachining and roll-to-roll laser systems for the semiconductor, photovoltaic, glass, and display markets, introduced the microPREP PRO FEMTO laser micromachining system for high-speed atom probe tomography (APT) and cross-section sample preparation.
Fulfilling a critical need for atomic-scale materials analysis, the microPREP PRO FEMTO system features a femtosecond laser and optimized optical setup, which enables micrometer-precision removal of material in minutes versus many hours with focused ion beam (FIB) milling while avoiding mechanical and thermal damage to the sample. The microPREP PRO FEMTO enables APT microtip coupons to be prepared directly from the sample material with automated workflows. This frees up valuable FIB resources to be utilized more cost effectively for final preparation steps only, such as final annular focused milling and polishing of the microtips.
Traditionally, APT sample preparation processes have been based on electrolytic or ion-based thinning workflows. Both workflows require mechanical preparation steps that introduce mechanical stress to the specimen, which can affect the overall quality and yield. Using FIB milling for the preparation process to avoid mechanical stress can take many hours to complete and requires specialized lift-out of the specimen, which introduces risk of damaging the specimen. Since FIB systems are costly, this approach also ties up FIB resources and results in very high operational costs for the user.
Some systems combine a laser for high-speed ablation and an FIB for final polishing in a single platform. However, this approach creates capacity bottlenecks since only one process can be used at a time. In addition, since laser preparation ablates high volumes of material, particle contamination inside the analytic area of combination laser/FIB tools becomes a much bigger issue and its removal is difficult due to the vacuum conditions inside the isolated laser or process chamber. Short pulse lasers can also cause large heat-affected zones, which can not only damage the sample but also can modify the structure of the probe tips, leading to inaccurate measurement results.
Unlike these other approaches, the microPREP PRO FEMTO is a dedicated laser micromachining solution that utilizes a femtosecond laser to provide the high speed, accuracy, cost-effectiveness, and versatility that research labs and universities require for APT sample preparation and cross-section analysis.
The microPREP PRO FEMTO can mill samples down to two microns from the final pillar – reducing APT sample preparation time from many hours to just minutes compared to FIB milling. Its femtosecond laser source limits the HAZ of the working sample to a few nanometers, compared to sub-micrometer-range HAZ with picosecond lasers. The system also features an optimized optical setup that includes a telecentric objective, which enables higher precision when preparing APT microtip coupons. This is especially important for coupons containing many APT pillars. The optical setup also features a shorter focal length and smaller laser spot size, adding to its high precision.
It also features 3D-Micromac’s integrated proprietary CO2 Snow Jet contactless, non-abrasive cleaning system, which uses compressed air and dry ice in a normal atmosphere to safely remove particles from the surface of the sample following the laser preparation process.
The microPREP PRO FEMTO also includes multiple pre-defined workflows, which facilitate setup and operation, and enable its use for a variety of use cases and applications.
Image – The microPREP PRO FEMTO laser micromachining system for high-speed atom probe tomography and cross-section sample preparation.
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3D-Micromac AG
