COMPOSITE HARDMASK ARCHITECTURE AND METHOD OF CREATING NON-UNIFORM CURRENT PATH FOR SPIN TORQUE DRIVEN MAGNETIC TUNNEL JUNCTION

摘要

A magnetic tunnel junction (MTJ) storage element and method of forming the MTJ are disclosed. The magnetic tunnel junction (MTJ) storage element includesa pinned layer, a barrier layer, a free layer and a composite hardmask or top electrode. The composite hardmask / top electrode architecture is configured to provide a non-uniform current path through the MTJ storage element and is formed from electrodes having different resistance characteristics coupled in parallel. An optional tuning layer interposed between the free layer and the top electrode helps to reduce the damping constant of the free layer.