Non-Destructive X-Ray Imaging of Patterned Delta-Layer Devices in Silicon
Non-Destructive X-Ray Imaging of Patterned Delta-Layer Devices in Silicon
复制标题
硅中图案化 Delta 层器件的无损 X 射线成像
DOI：
10.1002/aelm.202201212
复制
发表时间：
2023
影响因子：
6.2
通讯作者：
D'Anna N
中科院分区：
文献类型：
--
作者：
D'Anna N
集成电子器件小型化的进步催生了硅中原子和纳米尺寸的掺杂剂器件。这种结构可以通过氢抗蚀光刻法使用各种掺杂剂（例如磷和砷）常规制造。然而，非破坏性地获得最终结构的原子物种特定图像的能力仍然是一个尚未解决的挑战，这将是构建更复杂的纳米级设备（例如量子协处理器）不可或缺的工具。在这里，利用 X 射线荧光创建 Si 中 As 掺杂剂的元素特定图像，掺杂剂密度采用绝对单位，分辨率受光束焦点尺寸（此处 ≈1 µm）限制，而不影响器件的低温电子特性。将 X 射线数据提供的砷密度与霍尔效应测量以及标准不可重复扫描隧道显微镜和二次离子质谱技术得出的砷密度进行比较。在 X 射线实验之前和之后，我们还测量了磁导，其主要是弱局域化，这是一种对样品尺寸和无序性极其敏感的量子干涉效应。尽管器件暴露在 1.5 × 1010Sv (1.5 × 1016Rad cm−2) 的 X 射线下，但所有输运数据均未改变在实验误差范围内，对应于典型 As 原子辐射引起的运动的上限为 0.2 埃，活化的载流子贡献掺杂剂的损失上限为 3%。借助下一代同步加速器辐射源和更先进的光学器件，作者预计将有可能获得 5 nm 解析半径内的单个掺杂原子的 X 射线图像。
The progress of miniaturization in integrated electronics has led to atomic and nanometer‐sized dopant devices in silicon. Such structures can be fabricated routinely by hydrogen resist lithography, using various dopants such as P and As. However, the ability to non‐destructively obtain atomic‐species‐specific images of the final structure, which would be an indispensable tool for building more complex nano‐scale devices, such as quantum co‐processors, remains an unresolved challenge. Here, X‐ray fluorescence is exploited to create an element‐specific image of As dopants in Si, with dopant densities in absolute units and a resolution limited by the beam focal size (here ≈1 µm), without affecting the device's low temperature electronic properties. The As densities provided by the X‐ray data are compared to those derived from Hall effect measurements as well as the standard non‐repeatable, scanning tunneling microscopy and secondary ion mass spectroscopy, techniques. Before and after the X‐ray experiments, we also measured the magneto‐conductance, which is dominated by weak localization, a quantum interference effect extremely sensitive to sample dimensions and disorder. Notwithstanding the 1.5 × 1010Sv (1.5 × 1016Rad cm−2) exposure of the device to X‐rays, all transport data are unchanged to within experimental errors, corresponding to upper bounds of 0.2 Angstroms for the radiation‐induced motion of the typical As atom and 3% for the loss of activated, carrier‐contributing dopants. With next generation synchrotron radiation sources and more advanced optics, the authors foresee that it will be possible to obtain X‐ray images of single dopant atoms within resolved radii of 5 nm.