A read sensor of the current-perpendicular-to-the-planes (CPP) type
includes a sensor stack structure formed in a central region between
first and second shield layers which serve as leads for the read sensor;
insulator layers formed in side regions adjacent the central region; seed
layer structures formed over the insulator layers in the side regions;
and hard bias layers formed over the seed layer structures in the side
regions. The hard bias layers are made of a nitrogenated cobalt-based
alloy, such as nitrogenated cobalt-platinum (CoPt). Suitable if not
exemplary coercivity and squareness properties are exhibited using the
nitrogenated cobalt-based alloy. The hard bias layers may be formed by
performing an ion beam deposition of cobalt-based materials using a
sputtering gas (e.g. xenon) and nitrogen as a reactive gas.