Performance of Co/Al2O3/NiFe magnetic tunnel junctions prepared by a two-step rf plasma oxidation method

Abstract

A two-step rf plasma oxidation technique of an insulating layer has been performed to enhance electrical and structural properties of magnetic tunnel junction (MTJ) devices. Comparison was made by analyzing properties of the MTJ oxidized by conventional rf and two-step rf plasma oxidation methods. Experimentally observed results give improved surface imaging and sufficient oxygen contents of the insulating layer under the two-step oxidation method. In addition, electrical breakdown voltage and magnetoresistance of the MTJ were increased from 0.7 to 1.8 V and from 4.5% to 6.8%, respectively, correlated with improved structural information.