A Modular Atom Probe Concept: Design, Operational Aspects, and Performance of an Integrated APT-FIB/SEM Solution.

Atomic probe tomography (APT) is able to generate three-dimensional chemical maps in atomic resolution. The required instruments for APT have evolved over the last 20 years from an experimental to an established method of materials analysis. Here, we describe the realization of a new modular instrument concept that allows the direct attachment of APT to a dual-beam SEM microscope with the main achievement of fast and direct sample transfer and high flexibility in chamber and component configuration. New operational modes are enabled regarding sample geometry, alignment of tips, and the microelectrode. The instrument is optimized to handle cryo-samples at all stages of preparation and storage. It comes with its own software for evaluation and reconstruction. The performance in terms of mass resolution, aperture angle, and detection efficiency is demonstrated with a few application examples.