Immunity of nanoscale magnetic tunnel junctions with perpendicular magnetic anisotropy to ionizing radiation
Immunity of nanoscale magnetic tunnel junctions with perpendicular magnetic anisotropy to ionizing radiation
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DOI：
10.1038/s41598-020-67257-2
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发表时间：
2020-06-23
影响因子：
4.6
通讯作者：
Krivorotov, Ilya N.
中科院分区：
文献类型：
--
作者：
Montoya, Eric Arturo;Chen, Jen-Ru;Krivorotov, Ilya N.
自旋转移矩磁性随机存取存储器（STT-MRAM）是下一代存储器的有希望的候选者，因为它是非易失性的、快速的并且具有无限的耐久性。STT-MRAM的另一个重要方面是其核心组件，即纳米级磁性隧道结（MTJ），被认为是抗辐射的，这使其对空间和核技术应用具有吸引力。然而，STT-MRAM写入过程中的电离辐射的影响的研究缺乏的MTJ与垂直磁各向异性（pMTJ）所需的可扩展的应用程序。特别是，极端总电离剂量对垂直磁各向异性的影响，这对热稳定性和临界写入电流起着至关重要的作用的问题，仍然是开放的。在这里，我们报告测量的影响，高剂量的伽马和中子辐射的纳米级pMTJ中使用的STT-MRAM。我们表征了辐照前后的隧穿磁电阻、磁场开关和电流感应开关。我们的研究结果表明，所有这些关键属性的纳米级MTJ相关的STT-MRAM应用是强大的电离辐射。此外，我们在伽马射线环境中进行热驱动随机开关的实验。这些结果表明，纳米级的MTJ是有前途的积木辐射硬非冯诺依曼计算。
Spin transfer torque magnetic random access memory (STT-MRAM) is a promising candidate for next generation memory as it is non-volatile, fast, and has unlimited endurance. Another important aspect of STT-MRAM is that its core component, the nanoscale magnetic tunneling junction (MTJ), is thought to be radiation hard, making it attractive for space and nuclear technology applications. However, studies on the effects of ionizing radiation on the STT-MRAM writing process are lacking for MTJs with perpendicular magnetic anisotropy (pMTJs) required for scalable applications. Particularly, the question of the impact of extreme total ionizing dose on perpendicular magnetic anisotropy, which plays a crucial role on thermal stability and critical writing current, remains open. Here we report measurements of the impact of high doses of gamma and neutron radiation on nanoscale pMTJs used in STT-MRAM. We characterize the tunneling magnetoresistance, the magnetic field switching, and the current-induced switching before and after irradiation. Our results demonstrate that all these key properties of nanoscale MTJs relevant to STT-MRAM applications are robust against ionizing radiation. Additionally, we perform experiments on thermally driven stochastic switching in the gamma ray environment. These results indicate that nanoscale MTJs are promising building blocks for radiation-hard non-von Neumann computing.