Device-to-device variability of CoFeB/MgO based STT-MRAMs is studied based on experiments and simulations taking into account the influence of interface quality, temperature variation and device dimensionality. Metal-induced gap states resulting from electron transfer at the ferromagnet-tunnel barrier interface significantly influence the effective energy barrier height of these devices irrespective of their diameters. Switching voltage and parallel - antiparallel resistance values vary by as much as 43% and 30% respectively for about 13% variation of the energy barrier, whereas the tunneling magnetoresistance remains typically unaffected. WRITE cycles of highly scaled STT-MRAMs are therefore more susceptible to device-to-device variations resulting from microscopic variations in the interface quality, rather than the READ cycles. Such variations are observed to be independent of temperature, as well as spatial distribution of the defects.

中文翻译：

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MgO自旋传递转矩磁性RAM中接口质量和缺陷感应变异性的分析和仿真

基于实验和模拟，研究了基于CoFeB / MgO的STT-MRAM的器件间差异，其中考虑了接口质量，温度变化和器件尺寸的影响。由铁磁体-隧道势垒界面处的电子转移引起的金属诱导的间隙状态，无论它们的直径如何，都会显着影响这些器件的有效能垒高度。对于约13％的能垒变化，开关电压和并联-反并联电阻值分别变化高达43％和30％，而隧道磁阻通常保持不受影响。因此，大规模的STT-MRAM的WRITE周期更容易受到接口质量的微观变化而不是READ周期引起的设备间变化的影响。