Fabrication of current-induced magnetization switching devices using etch-back planarization process

A patterning process for nanoscale current-perpendicular-to-plane magnetic devices was developed. Spin valve and magnetic tunnel junction (MTJ) pillars are patterned using electron-beam lithography and subsequent hard mask deposition and ion milling. Photoresist etch-back method is used to planarize the insulation layer, deposited on top of the spin valve/MTJ pillars, prior to top lead deposition. This method allows for a reduction of shadowing effect associated with the use of resist mask for ion milling. Critical switching current of ~6× 107 A cm2 was observed for spin valve nanopillars with clear field dependence of the switching current, which is comparable to the reported value for metallic system.