解决三甲和水原子层沉积半反应的热量
Ashley R Bielinski1, Ethan P Kamphaus1, Lei Cheng1
1Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.
Journal of the American Chemical Society
|August 9, 2022
概括
原子层沉积 (ALD) 研究揭示了新的热力学和动力学见解. 烧电热量计显示ALD半反应释放的热量超过预测,需要精细的表面化学模型.
科学领域:
- 材料科学
- 表面化学
- 纳米技术
背景情况:
- 原子层沉积 (ALD) 是一个关键的表面合成技术,依赖于自我限制的前体反应.
- 在ALD中提高精度,包括区域和地点选择性增长,需要更深入地了解其底层表面化学.
- 现有的ALD热力学和动力学计算模型可能无法完全捕捉实验现实.
研究的目的:
- 研究三甲 (TMA) 和H2OALD半反应的热力学和动力学.
- 为管理这些基本的ALD过程的表面化学提供新的见解.
- 将实验结果与计算预测进行比较,并完善机械学理解.
主要方法:
- 使用在现场校准和时间解析的火电热量计进行高分辨率测量.
- 在ALD半反应中测量热释放,时间分辨率小于毫秒.
- 分析了前体输送和反应动力学,确定了多种动力学速率.
主要成果:
- TMA和H2O的ALD半反应释放的热量明显高于基于晶体Al2O3基质的模型所预测的热量 (分别为3.46和2.76 eV/Al).
- 实验热量与标准形成热量紧密结合.
- 观察到两个半反应的多重动态速率,TMA反应比H2O反应快100倍以上.
- 热电测量清楚地解决了前体输送和反应动力学.
结论:
- 实验结果突出了ALD表面化学现有计算模型的差异.
- 这项研究强调了需要精细的理论模型和机理理解,即使对于已成熟的ALD反应,如TMA/H2O.
- 在现场的热电测量是阐明ALD反应动态的强大工具.
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