3D Nanoprobes for magnetic force microscopy utilizing FEBID technology

Atomic force microscopy (AFM) provides detailed quantitative 3D nano-topography and
functional surface property information. However, advanced modes demand functional AFM
tips, often requiring additional thin film coatings. This leads to two primary drawbacks:
diminished lateral resolution due to increased apex radii, and the risk of delamination during
AFM operation, impacting resolution and lateral correlation to morphology. To fully utilize
advanced AFM modes, there is a need to develop new approaches for fabricating highresolution
functional nano-probes. Motivated by this, focused electron beam induced
deposition (FEBID) is used—an emerging additive direct-write manufacturing technology for
novel 3D nano-probe concepts.[1] This study focuses on fabricating magnetic tips for
magnetic force microscopy (MFM), aiming for fully magnetic, coating-free characteristics.
Utilizing a HCo3Fe(CO)12 precursor,[2] the impact of FEBID process parameters is
investigated—including electron energies, beam currents, and precursor temperature—using
various characterization techniques. Subsequently, tip geometries are optimized to achieve
sharp apexes and robust overall designs to meet the demands of AFM operation. This yields
fabrication protocols delivering metal contents exceeding 90 at.% with sub-10 nm apex radii
consistently. Finally, the performance of these FEBID-based MFM tips is demonstrated,
focusing on lateral resolution, magnetic sensitivity, signal quality, and wear resistance.[3] The
results show that these introduced MFM tips outperform commercially available ones in all
aspects.