Optimized process for the fabrication of mesoscopic magnetic structures

We have used the advantage of the high etch selectivity between metals in a wet etching process to develop an optimized technique for engineering magnetic materials. This method is based on electron beam lithography and optimized pattern transfer by a combination of dry and wet etching. The technique has been used in fabricating mesoscopic Ni80Fe20 dots and wires with lateral dimensions down to 0.2 mu m. We have used scanning electron microscopy to verify the lateral sizes and edge acuity of the structures. The magnetic properties were characterized using magneto-optic Kerr effect and magnetoresistance measurements. A marked increase in the coercive held and the saturation held is seen as the width of the wire is decreased. The magnetoresistance change (partial derivative R) is found to increase significantly as the width of the wire is decreased. (C) 1997 American Institute of Physics.