Influence of ion beam milling parameters on MRAM switching

The influence of the ion milling parameters on the magnetization reversal of patterned NiFe/CoFe layers is investigated. In 4 /spl mu/m/spl times/2 /spl mu/m ellipse elements switching of the magnetization occurs through a two step process. The first step is associated with domain wall propagation and the second with vortex annihilation. Reversal fields are reduced by ion milling at low angles (25/spl deg/-35/spl deg/). Magnetization reversal fields also show a dependence on ion energy. Milling at low ion energies reduces the switching field and dispersion values. Lower magnetization reversal fields are obtained for thinner layers.