Fabrication and Magnetic Characterization of Embedded Permalloy Structures

Magnetic nanostructures embedded in silicon wafers were successfully fabricated by the damascene technique using electron beam lithography. The magnetic properties of embedded square dots (1μm in width and 100nm in height), rectangular dots (300nm×100nm in area and 100nm in height), and circular dots (100nm in diameter and 100nm in height) were investigated. Magnetic force microscopy (MFM) and vibrating sample magnetometer (VSM) measurements showed that the perpendicular anisotropy increased with the aspect ratio, due to a decrease in the areal size. Fine magnetic structures of the 300nm×100nm pattern were clearly resolved by using a special MFM with a low-moment tip.