Elliptical-ring magnetic arrays fabricated using zone-plate-array lithography

Zone-plate-array lithography and lift-off processing were employed to fabricate large arrays of elliptical-ring thin film magnets with widths of 600 nm and above. An undercut profile was created using WiDE™ antireflection coating spun underneath a PFI-88 resist layer. The process allowed for up to 60 - nm -thick sputtered magnetic multilayered structures. The magnetic properties of the elliptical ring arrays clearly show that the shape anisotropy induced by the ellipticity of the ring creates different magnetization reversal depending on the applied field direction. Magnetic force microscopy shows that the rings display magnetic states characteristic of ring structures, as well as sharp transitions between them. A fabrication process to produce magnetic memory prototypes based on these elliptical rings is presented.