In situ and ex situ processes for synthesizing metal multilayers with electronically conductive interfaces
In situ and ex situ processes for synthesizing metal multilayers with electronically conductive interfaces
复制标题
具有电子导电界面的金属多层膜的原位和非原位合成工艺
DOI：
10.1063/5.0084573
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发表时间：
2022-06
影响因子：
3.2
通讯作者：
Frank Angeles;Xinping Shi;Richard B. Wilson
中科院分区：
文献类型：
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作者：
Frank Angeles;Xinping Shi;Richard B. Wilson
许多技术应用和科学实验需要制备具有电子和导热界面的金属多层材料的工艺。我们研究了原位和非原位合成过程如何影响金属/金属界面的导热性。我们利用时域热反射实验研究了Au/Fe、Al/Cu和Cu/Pt双层样品中的热输运。我们量化了在沉积顶部金属层之前将底部金属层暴露于环境中的影响。我们观察到，对于Au/Fe，在沉积顶部Au层之前将Fe层暴露在空气中会显著阻碍界面电子电流。在沉积Al层之前，将Cu暴露在空气中可以有效地消除两个金属层之间的界面电子热流。暴露在空气中似乎对Cu/Pt体系中的界面输运没有影响。最后，我们表明，底层表面的短射频溅射蚀刻足以确保我们研究的所有材料中的热传导和导电金属/金属界面。我们用双温度模型分析了我们的结果，并对我们研究的9个样品的电子界面电导进行了绑定。我们的研究结果可以应用于薄膜合成，并促进对金属之间不同类型界面的电子热传导的基本理解。
A number of technological applications and scientific experiments require processes for preparing metal multilayers with electronically and thermally conductive interfaces. We investigate how in situ vs ex situ synthesis processes affect the thermal conductance of metal/metal interfaces. We use time-domain thermoreflectance experiments to study thermal transport in Au/Fe, Al/Cu, and Cu/Pt bilayer samples. We quantify the effect of exposing the bottom metal layer to an ambient environment prior to deposition of the top metal layer. We observe that for Au/Fe, exposure of the Fe layer to air before depositing the top Au layer significantly impedes interfacial electronic currents. Exposing Cu to air prior to depositing an Al layer effectively eliminates interfacial electronic heat currents between the two metal layers. Exposure to air appears to have no effect on interfacial transport in the Cu/Pt system. Finally, we show that a short RF sputter etch of the bottom layer surface is sufficient to ensure a thermally and electronically conductive metal/metal interface in all materials we study. We analyze our results with a two-temperature model and bound the electronic interface conductance for the nine samples we study. Our findings have applications for thin-film synthesis and advance fundamental understanding of electronic thermal conductance at different types of interfaces between metals.