发表机构
University of Queensland; National Taiwan University; Monash University; Shanghai University; The University of Melbourne; ALBA Synchrotron Light Source; Australian Nuclear Science and Technology Organisation（昆士兰大学; 台湾大学; 莫纳什大学; 上海大学; 墨尔本大学; 阿尔巴同步辐射光源; 澳大利亚核科学和技术组织）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文开发氢等离子体辅助原子层沉积技术，实现超导氮化钛薄膜的外延生长，解决了低温下结晶度与界面无序的控制难题，所得薄膜在2.2 K超导，适用于低温量子技术。
AI 中文摘要
原子层沉积（ALD）能够对薄膜生长进行精确、保形的控制，是半导体制造的关键技术，但其在超导量子电路中的应用受到限制，原因在于需要在低温下同时控制结晶度、化学计量比和界面无序度。在此，我们开发了氢等离子体辅助ALD技术，用于外延生长超导氮化钛（TiN）薄膜，利用氢等离子体步骤改变表面化学性质，以在每个沉积循环中抑制前驱体引入的杂质。同步辐射X射线散射显示，TiN在c面蓝宝石上实现了半共格外延，具有离散的晶体学畴和最小的长程结构无序。互补的X射线光谱和中子反射测量表明，整个薄膜中与氧相关的无序可忽略不计，且没有显著的氢掺入。所得TiN薄膜在2.2 K时表现出超导转变，动感电感为15 pH/sq，超导相干长度为14.6 nm，与测得的晶体相干长度相当。这些结果确立了氢等离子体辅助ALD作为结构有序超导TiN薄膜外延生长的途径，并证明ALD的纳米尺度控制可扩展到适用于低温量子技术的材料。
英文摘要
Atomic layer deposition (ALD) offers precise, conformal control of thin-film growth and is a workhorse for semiconductor manufacturing, but its use in superconducting quantum circuits is constrained by the need to simultaneously control crystallinity, stoichiometry and interfacial disorder at cryogenic temperatures. Here we develop hydrogen plasma assisted ALD to epitaxially grow superconducting titanium nitride (TiN) thin films, using a hydrogen plasma step to modify the surface chemistry to suppress precursor-derived impurities during each deposition cycle. Synchrotron X-ray scattering reveals semi-coherent epitaxy of TiN on c-plane sapphire, with discrete crystallographic domains and minimal long-range structural disorder. Complementary X-ray spectroscopy and neutron reflectometry show negligible oxygen-related disorder throughout the film and no substantial hydrogen incorporation. The resulting TiN films exhibit a superconducting transition at 2.2 K, a kinetic inductance of 15 pH/sq and a superconducting coherence length of 14.6 nm, comparable to the measured crystal coherence length. These results establish hydrogen plasma assisted ALD as a route to structurally ordered superconducting TiN thin film epitaxy and demonstrate that the nanoscale control of ALD can be extended to materials suitable for cryogenic quantum technologies.
