Improved Current Switching Symmetry Of Magnetic Tunneling Junction And Giant Magnetoresistance Devices With Nano-Current-Channel Structure

The asymmetry of the switching current in magnetic tunneling junction (MTJ) and giant magnetoresistance (GMR) spin torque transfer devices was reported in both theory and experiment. This is one of the key challenges for future magnetic random access memory applications. In this work, the switching symmetry was greatly improved by inserting a nano-current-channel (NCC) structure in both MTJ and GMR devices. With the NCC structure, the current induced magnetization switching is nonuniform with initiation cites induced by locally high current density. The critical switching current density in both switching directions was successfully reduced while the degree of switching asymmetry {[(J(c)(P-AP)-J(c)(AP-P))/J(c)(AP-P)]x100%} was improved as well. (c) 2008 American Institute of Physics.