Batch fabrication of ultra-sharp atomic force microscope probes with stair-shaped handles for high-precision imaging

Atomic force microscope (AFM) systems rely on silicon (Si) probes for precise nanoscale characterization across diverse environments. However, fabricating high-aspect-ratio (HAR) and sharp Si tips and optimizing the handle geometries remain significant challenges. Conventional HAR probe fabrication methods lack scalability, precision, and cost efficiency, while cuboid-shaped handles risk obstructing laser detection and limiting compatibility. This study presents an innovative batch-fabrication strategy for high-performance Si AFM probes that integrate ultra-sharp HAR tips, rectangular cantilevers, and universally compatible stair-shaped handles. Notably, the tip fabrication process employs only low-cost microscale ultraviolet (UV) lithography, while still achieving nanoscale structural resolution. The fabricated probes exhibit a tip apex radius of 5 nm and a half-cone angle of 7.5°, enabling high-resolution and high-fidelity imaging. The novel stair-shaped handle geometry is introduced and fabricated via a single-step dry etching process, which provides unobstructed laser detection and ensures compatibility with a broad range of commercial AFM platforms. Durability testing demonstrates stable scanning performance for up to 8 hours within the 100 nm precision range, confirming the mechanical reliability of the design. This scalable, reproducible, and high-yield fabrication strategy represents a significant advancement in HAR AFM probe development, providing enhanced performance and extended applicability for diverse nanoscale imaging applications.