There has been a persistent effort to understand and control the incorporation of metal impurities in semiconductors at nanoscale, as it is important for semiconductor processing from growth, doping to making contact. Previously, the injection of metal atoms into nanoscaled semiconductor, with concentrations orders of magnitude higher than the equilibrium solid solubility, has been reported, which is often deemed to be detrimental. Here our theoretical exploration reveals that this colossal injection is because gold or aluminum atoms tend to substitute Si atoms and thus are not mobile in the lattice of Si. In contrast, the interstitial atoms in the Si lattice such as manganese (Mn) are expected to quickly diffuse out conveniently. Experimentally, we confirm the self-inhibition effect of Mn incorporation in nanoscaled silicon, as no metal atoms can be found in the body of silicon (below 10¹⁷ atoms per cm⁻³) by careful three-dimensional atomic mappings using highly focused ultraviolet-laser-assisted atom-probe tomography. As a result of self-inhibition effect of metal incorporation, the corresponding field-effect devices demonstrate superior transport properties. This finding of self-inhibition effect provides a missing piece for understanding the metal incorporation in semiconductor at nanoscale, which is critical not only for growing nanoscale building blocks, but also for designing and processing metal–semiconductor structures and fine-tuning their properties at nanoscale.

人们一直在努力理解和控制纳米级半导体中金属杂质的掺入，因为这对于半导体从生长、掺杂到接触的加工很重要。以前，已经报道了将金属原子注入纳米级半导体中，其浓度比平衡固溶度高几个数量级，这通常被认为是有害的。在这里，我们的理论探索表明，这种巨大的注入是因为金或铝原子倾向于取代 Si 原子，因此在 Si 的晶格中不能移动。相比之下，硅晶格中的间隙原子如锰 (Mn) 有望快速方便地扩散出去。通过实验，我们证实了 Mn 掺入纳米级硅的自抑制效应，¹⁷个原子/cm ^-3）通过使用高度聚焦的紫外激光辅助原子探针断层扫描进行仔细的三维原子映射。由于金属掺入的自抑制效应，相应的场效应器件表现出优异的传输性能。自抑制效应的这一发现为理解纳米级半导体中的金属掺入提供了一个缺失的部分，这不仅对于生长纳米级构件至关重要，而且对于设计和加工金属-半导体结构以及在纳米级微调它们的性能也至关重要.