垂直形状异形MRAM的热力学特性和切换动态
Wayne Lack1, Sarah Jenkins1, Andrea Meo1
1School of Physics, Engineering and Technology, University of York, York YO10 5DD, United Kingdom.
Journal of physics. Condensed matter : an Institute of Physics journal
|December 29, 2023
概括
研究人员探索了磁性RAM (MRAM) 塔结构,以提高稳定性和降低功耗. 将自由层稀释到18nm以下会损害形状异构性和稳定性,影响MRAM性能.
科学领域:
- 材料科学 材料科学 材料科学
- 电气工程 电气工程
- 计算机工程 计算机工程
背景情况:
- 现代随机存取内存 (RAM) 面临着电力消耗的挑战,需要低功耗的非挥发性替代品,如磁性RAM (MRAM).
- 基于CoFeB/MgO磁结的MRAM需要高热稳定性和低写电流,以适应20nm以下的缩放,以匹配当前的RAM密度.
- 通过塔结构利用垂直形状异质性,其中自由层厚度超过宽度,是MRAM的最新发展.
研究的目的:
- 为了研究薄圆柱形MRAM塔的温度依赖性质.
- 分析缩小自由层厚度 (从48nm到8nm) 对MRAM性能和稳定性的影响.
- 了解缩放MRAM设备中的切换机制.
主要方法:
- 使用原子模型模拟5nm直径的MRAM塔.
- 将自由层厚度从48nm缩小到8nm.
- 从歇斯底里数据分析了切换场分布,以了解温度依赖性质和切换机制.
主要成果:
- 热波动在工作温度下显著影响MRAM切换机制.
- 自由层厚度降低至18nm以下,导致形状异构性和稳定性快速丧失,即使在0凯尔文.
- 交换机制随着自由层厚度的变化而变化:8纳米层的连贯旋转与通过更厚的塔的域壁传播的不连贯旋转.
结论:
- 在18nm以下的MRAM自由层的缩放严重影响形状异构性和热稳定性,阻碍性能.
- 切换机制从不连贯的域壁传播过渡到连贯的旋转,随着自由层厚度的减少.
- 优化自由层厚度对于实现稳定和高效的MRAM设备至关重要.
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