The miniaturization of electronic devices requires thin films with electrical conductivities that are comparable to those of bulk metals. However, ultrathin coinage metal films inevitably suffer from increased electrical resistivity compared with bulk metals, hindering their performance in miniaturized electronics. This study presents a novel approach to achieve near-bulk resistivity in sub-10-nm-thick Au films on heterogeneous oxide substrates. Our method utilizes O-incorporated epitaxial growth of Au films on α-AlO(0001) substrates followed by thermal treatment. This strategy promoted an exceptional film crystallinity, particularly favoring the Au(111) orientation, and significantly reduced the resistivity. Notably, the 8-nm-thick Au film exhibited a record-low resistivity of 3.7 μΩ⋅cm, approaching that of a significantly thicker (60-nm) Au film. This performance surpasses those of Cu and Ag film electrodes of similar thicknesses. Density functional theory calculations provided theoretical insights into the mechanism of O-induced epitaxial growth. Our findings demonstrate that improved crystallinity mitigates the strong dependence of resistivity on the thickness reduction. This study challenges the conventional view of resistivity increase in ultrathin metal films and offers a promising path toward high-performance miniaturized electronics with superior electrical properties.

中文翻译：

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摆脱厚度缩小效应，实现亚 10nm Au 薄膜的接近体电阻率


电子设备的小型化需要具有与块状金属相当的电导率的薄膜。然而，与块状金属相比，超薄造币金属薄膜不可避免地会遇到电阻率增加的问题，从而阻碍了它们在小型电子产品中的性能。这项研究提出了一种新颖的方法，可以在异质氧化物基板上的亚 10 nm 厚的金薄膜中实现接近体电阻率。我们的方法利用在 α-Al2O(0001) 基板上掺氧外延生长 Au 薄膜，然后进行热处理。这种策略促进了优异的薄膜结晶度，特别有利于 Au(111) 取向，并显着降低了电阻率。值得注意的是，8 nm 厚的 Au 薄膜表现出 3.7 μΩ·cm 的创纪录低电阻率，接近明显更厚（60 nm）的 Au 薄膜。该性能超过了相似厚度的铜膜和银膜电极。密度泛函理论计算为 O 诱导外延生长的机制提供了理论见解。我们的研究结果表明，结晶度的提高减轻了电阻率对厚度减少的强烈依赖性。这项研究挑战了超薄金属薄膜电阻率增加的传统观点，并为实现具有卓越电性能的高性能微型电子产品提供了一条有前途的道路。