We investigate the heavy ions irradiation effect on the spin transfer torque film stacks with perpendicular magnetic anisotropy. Samples are exposed to 175MeV Cl ion and 235MeV Ge ion at the fluence of 1x10⁵ ions/cm² and 1x10⁶ ions/cm². Measurements of magnetization vs. magnetic field are performed on the film stacks before and after irradiation. The results exhibit that magnetic properties of free layer (CoFeB) in the spin transfer torque film keeps unchanged while magnetic properties of the synthetic antiferromagnet layer (Co/Pt) and the ferromagnetic exchange coupling between reference layer (CoFeB) and synthetic antiferromagnet layer through W layer have changed significantly when the fluence of the two kinds of ions reach 1x10⁶ ions/cm². We analysis the irradiation damage of the film stacks by SRIM simulation and give a reasonable explanation for this phenomenon. Thus, our work demonstrates that perpendicular spin transfer torque MRAM technology itself, the memory element construction, is subject to damage from heavy ions irradiation.

我们研究了重离子辐照对具有垂直磁各向异性的自旋转移矩薄膜堆栈的影响。样品以1x10 ⁵离子/cm ²和1x10 ⁶离子/cm ²的通量暴露于175MeV Cl离子和235MeV Ge离子。在辐照之前和之后对薄膜叠层进行磁化强度与磁场的测量。结果表明，自旋转移矩薄膜中自由层 (CoFeB) 的磁性能保持不变，而合成反铁磁层 (Co/Pt) 的磁性能以及参考层 (CoFeB) 与合成反铁磁层之间通过 W 的铁磁交换耦合当两种离子的通量达到 1x10 时，层数发生了显着变化^6个离子/cm ²。我们通过 SRIM 模拟分析了薄膜叠层的辐照损伤，并对这种现象给出了合理的解释。因此，我们的工作表明，垂直自旋转移矩 MRAM 技术本身，即存储元件结构，会受到重离子辐射的损坏。