Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, NSW 2052, Australia.
Nat Nanotechnol. 2012 Feb 19;7(4):242-6. doi: 10.1038/nnano.2012.21.
The ability to control matter at the atomic scale and build devices with atomic precision is central to nanotechnology. The scanning tunnelling microscope can manipulate individual atoms and molecules on surfaces, but the manipulation of silicon to make atomic-scale logic circuits has been hampered by the covalent nature of its bonds. Resist-based strategies have allowed the formation of atomic-scale structures on silicon surfaces, but the fabrication of working devices-such as transistors with extremely short gate lengths, spin-based quantum computers and solitary dopant optoelectronic devices-requires the ability to position individual atoms in a silicon crystal with atomic precision. Here, we use a combination of scanning tunnelling microscopy and hydrogen-resist lithography to demonstrate a single-atom transistor in which an individual phosphorus dopant atom has been deterministically placed within an epitaxial silicon device architecture with a spatial accuracy of one lattice site. The transistor operates at liquid helium temperatures, and millikelvin electron transport measurements confirm the presence of discrete quantum levels in the energy spectrum of the phosphorus atom. We find a charging energy that is close to the bulk value, previously only observed by optical spectroscopy.
在原子尺度上控制物质并以原子精度构建器件是纳米技术的核心。扫描隧道显微镜可以在表面上操纵单个原子和分子，但由于硅的共价键性质，其原子级逻辑电路的制造一直受到阻碍。基于抗蚀剂的策略已经允许在硅表面上形成原子级结构，但制造工作器件，如具有极短栅长的晶体管、基于自旋的量子计算机和孤立掺杂光电设备，需要能够以原子精度将单个原子定位在硅晶体中。在这里，我们使用扫描隧道显微镜和氢抗蚀剂光刻技术的组合，展示了一种单原子晶体管，其中一个磷掺杂原子已经被确定性地放置在具有一个晶格位置的空间精度的外延硅器件结构中。该晶体管在液氦温度下工作，毫开尔文电子输运测量证实了磷原子能谱中存在离散量子能级。我们发现一个接近体值的充电能量，之前只有通过光学光谱才能观察到。
