Perpendicular magnetic tunnel junctions with multi-interface free layer

Future generations of magnetic random access memory demand magnetic tunnel junctions that can provide simultaneously high magnetoresistance, strong retention, low switching energy, and small cell size below 10 nm. Here, we study perpendicular magnetic tunnel junctions with composite free layers, where multiple ferromagnet/nonmagnet interfaces can contribute to the thermal stability. Different nonmagnetic materials (MgO, Ta, and Mo) have been employed as the coupling layers in these multi-interface free layers. The evolution of junction properties under different annealing conditions is investigated. A strong dependence of the tunneling magnetoresistance on the thickness of the first CoFeB layer has been observed. In junctions where Mo and MgO are used as coupling layers, a large tunneling magnetoresistance above 200% has been achieved after 400 °C annealing.Semiconductor Research Corporation12 month embargo; published online: 15 December 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu