Electrodeposition of patterned magnetic nanostructures

Abstract

We report on fabrication and characterization of two types of devices, both with submicronic dimensions, and fabricated by combining lithography and electrodeposition. The first device, obtained by combining electron-beam lithography and electrodeposition, was devised to measure the current perpendicular to the plane giant magnetoresistance (CPP-GMR) of a single permalloy/copper multilayered nanopillar (height ∼0.3 μm, diameter ∼0.1 μm). Besides the fundamental interest of the spin-dependent transport properties in such nanoscaled magnets, this system is a potential candidate as a CPP-GMR sensor used, for example, to read very high-density magnetic storage. The second device, relevant for high-density storage media, consists in large areas (4×4 mm2) of magnetic permalloy dots (diameter ∼0.26 μm, period ∼0.4 μm) electrodeposited in a x-ray patterned photoresist matrix. We study the magnetic behavior of such mesoscopic pillars as a function of their height. We emphasize that our processes are less damaging for the nanostructures, in comparison with samples prepared by high vacuum deposition followed by lithography. This is because our magnetic nanostructures are electrodeposited after the whole lithographic process.