Study about the damaged mechanism of the patterned perpendicular magnetic tunnel junctions by hydrogen ion treatments

In order to study about the degradation mechanism of the patterned perpendicular magnetic tunnel junctions (MTJs) by the hydrogen plasma condition (HPC) and hydrogen etching condition (HEC) treatments, we calculated the magneto-resistance (MR) and resistance (R) trends of the patterned MTJs at several electric and magnetic conditions of the damaged layer and correlated calculated results with experimental trends by the HPC and HEC treatments. As a result of this study, it has been recognized that hydrogen by the HPC treatment just reacts with the damaged layer at the edge of patterned MTJs, while it by the HEC treatment reacts with damage-less area of the patterned MTJs as well as the damaged layer. It is because the applied bias voltage during the HEC process can accelerate the reactivity of hydrogen plasma ions to penetrate into the interface between MgO and CoFeB of the patterned MTJs. In addition, it has been also recognized that the damaged layer generated by hydrogen plasma ions makes the MR and R degradations of patterned MTJs by interference with flows of current.