Fabrication of magnetic submicron-wire channels for the investigation of magnetization reversal

Abstract

We have demonstrated a process for fabricating magnetic structures with feature sizes ranging from 50 nm to several hundred microns using high-resolution electron beam lithography with 50 keV electrons followed by Ti evaporation and liftoff. The Ti was used as an etch mask for ion milling and then removed by SF6 reactive ion etching. A variety of magnetic fine structures were fabricated on (CoNi/Pt)6 multilayer substrates. In particular, submicron-wire channels, which connect a number of microscopic squares to a large reservoir area, were obtained. The magnetization reversal processes in submicron wire channels were studied with a conventional magneto-optical Kerr microscope. We found that the switching field for magnetization and the reversal behavior of the connected microscopic squares strongly depend on the channel wire width, thereby providing a way to study domain wall motion in a subwavelength scale with diffraction limited methods.