Magnetic and Electrical Properties of Magnetic Tunnel Junctions With Radical Oxidized MgO Barriers

This work focuses on magnetic tunnel junctions with a MgO barrier layer made by RF-sputtering and radical oxidation. In case of RF-sputtered MgO, its crystal orientation, MR and RA values very sensitively depend on the chamber atmosphere. The MR ratio of 97% in radical oxidized MgO is obtained at 0.4 V, which is slightly higher than RF-sputtered MgO. Also, its RA is smaller than that of RF-sputtered MgO. These improved MgO properties are originated from the improvement of the crystal orientation of MgO(200) and the decrease of OH component within the MgO barrier. In addition, the breakdown voltage in radical oxidized MgO is higher than that of RF-sputtered MgO at the same MgO thickness.