Różański Piotr T, Bryant Garnett W, Zieliński Michał
Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Toruń, Poland.
Nanoscale Device Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899-8423, USA.
Sci Rep. 2024 Aug 5;14(1):18062. doi: 10.1038/s41598-024-67903-z.
The design and implementation of dopant-based silicon nanoscale devices rely heavily on knowing precisely the locations of phosphorous dopants in their host crystal. One potential solution combines scanning tunneling microscopy (STM) imaging with atomistic tight-binding simulations to reverse-engineer dopant coordinates. This work shows that such an approach may not be straightforwardly extended to double-dopant systems. We find that the ground (quasi-molecular) state of a pair of coupled phosphorous dopants often cannot be fully explained by the linear combination of single-dopant ground states. Although the contributions from excited single-dopant states are relatively small, they can lead to ambiguity in determining individual dopant positions from a multi-dopant STM image. To overcome that, we exploit knowledge about dopant-pair wave functions and propose a simple yet effective scheme for finding double-dopant positions based on STM images.
基于掺杂剂的硅纳米级器件的设计与实现，在很大程度上依赖于精确知晓磷掺杂剂在其主体晶体中的位置。一种潜在的解决方案是将扫描隧道显微镜（STM）成像与原子紧束缚模拟相结合，以逆向工程掺杂剂坐标。这项工作表明，这种方法可能无法直接扩展到双掺杂剂系统。我们发现，一对耦合磷掺杂剂的基态（准分子态）通常不能通过单掺杂剂基态的线性组合得到充分解释。尽管来自单掺杂剂激发态的贡献相对较小，但它们会导致在从多掺杂剂STM图像确定单个掺杂剂位置时产生模糊性。为克服这一问题，我们利用关于掺杂剂对波函数的知识，提出了一种基于STM图像寻找双掺杂剂位置的简单而有效的方案。
