Focused ion beam modified atomic force microscope tips for scanning hall probe microscopy

A 50 nm thick and 40 nm wide bismuth film is thermally evaporated onto the AFM tip. A high precision focused ion beam (FIB) patterning technique is then used to image and accurately locate the apex of the tip and remove unwanted parts of the film in order to define the Hall sensor. From the generated SEM images, a cantilever and a pyramid-like tip of the FIB modified silicon nitride contact mode AFM sensor is shown.