Perpendicular magnetic tunnel junctions with multi-interface free layer
Perpendicular magnetic tunnel junctions with multi-interface free layer
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DOI：
10.1063/5.0066782
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发表时间：
2021-12-13
影响因子：
4
通讯作者：
Wang, Weigang
中科院分区：
文献类型：
--
作者：
Khanal, Pravin;Zhou, Bowei;Wang, Weigang
未来几代磁性随机存取存储器需要磁性隧道结，该隧道结能够同时提供高磁阻、强保留、低开关能量和低于 10 nm 的小单元尺寸。在这里，我们研究具有复合自由层的垂直磁性隧道结，其中多个铁磁体/非磁体界面可以有助于热稳定性。不同的非磁性材料（MgO、Ta 和 Mo）已被用作这些多界面自由层中的耦合层。研究了不同退火条件下结性能的演变。已经观察到隧道磁阻对第一 CoFeB 层的厚度有很强的依赖性。在采用Mo和MgO作为耦合层的结中，经过400℃退火后，获得了200%以上的大隧道磁阻。
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 & DEG;C annealing.