Fabrication and magnetisation measurements of variable-pitch gratings of cobalt on GaAs

A technique for engineering micron and sub-micron scale structures from magnetic films of transition metals has been developed using a combination of electron and ion beam lithography. The pattern is defined by a mask produced by 60kV electron beam lithography, enabling near-vertical sidewalls to be produced. The focused ion beam is rastered to etch cobalt in the mask openings. PMMA and aluminium masks have been assessed. High quality arrays of …