Magnetically refined tips for Scanning Force Microscopy

Cantilever probes with integrated tips are commercially available. They are routinely used for atomic force microscopy (AFM). For such probes a magnetic refinement of the silicon tip has been developed which results in a deposition of ferromagnetic materials like Nickel or CrCoTa at the top area of the tip. This method consists of essentially three steps: 1. a broad-area sputter-deposition of a ferromagnetic material of any kind, 2. a selective electron-beam induced carbon deposition at the top of the tip of adjustable extension and thickness and 3. a broad-area ion beam sputter-etching which removes the magnetic layer everywhere except underneath the carbon cap. Experiments indicate that the method is reliable and improves the resolution of magnetic force microscopy (MFM). The best lateral spatial resolution amounts 25 nm. Moreover, the domain structure of weak magnetic materials is not destroyed using such probes.