Position-controlled nanodeposition of magnets using an electropulsed scanning probe microscope

Scanning probe microscopes (SPM) have been used to change surfaces at nanometer scales. We report the deposition of magnets in user defined patterns using an electropulsed atomic force microscope (AFM). The patterns were fabricated by applying −12 V electrical pulses in the 10–40 Hz range between a commercial CoCr-covered Si tip and a crystalline n-doped Si wafer. The tip damage during deposition is negligible. Immediately after deposition the same tip was used for performing AFM and magnetic force microscopy (MFM) measurements on the fabricated patterns. Applying one isolated electrical pulse results in a pixel with a typical size of the order of 28 nm as measured by AFM. By combining the scanning ability of the SPM with the atmospheric deposition induced by electrical pulses on the tip, user-defined patterns can be fabricated. The height of the deposited patterns is of the order of 2–3 nm. The MFM measurements performed in different scanning directions show a preferential magnetization direction as shown by the higher fringe fields from the rectangles shorter edges.