Atomic-Scale Patterning of Arsenic in Silicon by Scanning Tunneling Microscopy
Atomic-Scale Patterning of Arsenic in Silicon by Scanning Tunneling Microscopy
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DOI：
10.1021/acsnano.9b08943
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发表时间：
2020-03-24
期刊：
影响因子：
17.1
通讯作者：
Curson, Neil J.
中科院分区：
文献类型：
--
作者：
Stock, Taylor J. Z.;Warschkow, Oliver;Curson, Neil J.
在过去的二十年里，通过使用扫描隧道显微镜和抗氢光刻技术，以原子尺度的精度在硅中定位磷原子，为未来的经典和量子计算技术制造了原型设备。尽管取得了这些成功，但磷化氢仍然是唯一被证明与抗氢光刻技术相容的供体前体分子。到目前为止，在原子尺度上放置替代掺杂剂的潜在好处仍未得到探索。在这项工作中，我们证明了砷硅原子尺度结构的成功制造。利用扫描隧道显微镜尖端，我们设计了一个单层氢掩膜，以砷为前体分子，选择性地将砷原子放置在Si（001）表面。我们充分阐明了砷在硅上的表面化学和反应途径（001），揭示了与磷化氢的显著差异。我们解释了与磷相比，这些差异如何导致砷的表面固定化和面内约束增强，以及0.24 +/- 0.04单层的剂量率无关的砷饱和密度。我们展示了利用硅分子束外延成功封装砷三角洲层，并发现了与磷制造的等效结构竞争的电学特性。砷三角洲层也被发现提供与类似制备的磷层一样好的约束，同时仍然保持80%的载流子活化和片电阻
Over the past two decades, prototype devices for future classical and quantum computing technologies have been fabricated by using scanning tunneling microscopy and hydrogen resist lithography to position phosphorus atoms in silicon with atomic-scale precision. Despite these successes, phosphine remains the only donor precursor molecule to have been demonstrated as compatible with the hydrogen resist lithography technique. The potential benefits of atomic-scale placement of alternative dopant species have, until now, remained unexplored. In this work, we demonstrate the successful fabrication of atomic-scale structures of arsenic-insilicon. Using a scanning tunneling microscope tip, we pattern a monolayer hydrogen mask to selectively place arsenic atoms on the Si(001) surface using arsine as the precursor molecule. We fully elucidate the surface chemistry and reaction pathways of arsine on Si(001), revealing significant differences to phosphine. We explain how these differences result in enhanced surface immobilization and in-plane confinement of arsenic compared to phosphorus, and a dose-rate independent arsenic saturation density of 0.24 +/- 0.04 monolayers. We demonstrate the successful encapsulation of arsenic delta-layers using silicon molecular beam epitaxy, and find electrical characteristics that are competitive with equivalent structures fabricated with phosphorus. Arsenic delta-layers are also found to offer confinement as good as similarly prepared phosphorus layers, while still retaining >80% carrier activation and sheet resistances of