Abstract Porous metal film has drawn plenty of attention due to the excellent reliability and potential of integration in current interconnects/electrodes technologies. However, the practical applications of porous metal film have been hampered by complex technique and poor electrical properties. Here, we report a one-step method to directly construct a unique sandwich-porous copper film combining with high mechanical and electrical performance by a simple sputtering process. Growth parameters, with emphases on substrate temperature and deposition time, are systematically investigated to provide direct experimental validation of the formation mechanism of the sandwich-porous films. Results demonstrate that by tuning a porous-factor ( β ) during the film deposition, it is possible to noticeably affect the surface topography, from columnar to porous and/or dense structure, and hence effectively control the formation of the sandwich-porous structure. Additionally, nanoindentation tests for the sandwich-porous films are also investigated, where high conductivity and super-elastic property are achieved due to the special microstructures with presence of nanoporous. This discovery may pave a facile and effective way to fabricate multifunctional porous metallic films for bottom-up fabrication schemes of next-generation devices in the microelectronics industry.

中文翻译：

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自下而上的夹心多孔铜膜：简便的构造、生长机制和超弹性

摘要 多孔金属薄膜由于其优异的可靠性和在当前互连/电极技术中的集成潜力而引起了广泛关注。然而，多孔金属薄膜的实际应用受到技术复杂和电性能差的阻碍。在这里，我们报告了一种通过简单的溅射工艺直接构建具有高机械和电气性能的独特夹心多孔铜膜的一步法。系统地研究了生长参数，重点是衬底温度和沉积时间，以提供对夹心多孔膜形成机制的直接实验验证。结果表明，通过在薄膜沉积过程中调整多孔因子 (β)，可以显着影响表面形貌，从柱状到多孔和/或致密结构，从而有效控制夹心多孔结构的形成。此外，还研究了夹心多孔薄膜的纳米压痕测试，由于纳米多孔的特殊微结构，实现了高导电性和超弹性。这一发现可能为制造多功能多孔金属薄膜铺平了一条简便有效的方法，用于微电子行业下一代器件的自下而上的制造方案。