Fabrication of atomic dopant wires at large scale is challenging. We explored the feasibility to fabricate atomic dopant wires by nano-patterning self-assembled dopant carrying molecular monolayers via a resist-free lithographic approach. The resist-free lithography is to use electron beam exposure to decompose hydrocarbon contaminants in vacuum chamber into amorphous carbon that serves as an etching mask for nanopatterning the phosphorus-bearing monolayers. Dopant wires were fabricated in silicon by patterning diethyl vinylphosphonate monolayers into lines with a width ranging from 1 μm down to 8 nm. The dopants were subsequently driven into silicon to form dopant wires by rapid thermal annealing. Electrical measurements show a linear correlation between wire width and conductance, indicating the success of the monolayer patterning process at nanoscale. The dopant wires can be potentially scaled down to atomic scale if the dopant thermal diffusion can be mitigated.

大规模制造原子掺杂线具有挑战性。我们探索了通过无抗蚀剂光刻方法对载有分子单分子层的自组装掺杂剂进行纳米构图来制造原子掺杂剂线的可行性。无抗蚀剂光刻是使用电子束曝光将真空室中的碳氢化合物污染物分解为无定形碳，该碳用作刻蚀掩模，用于对含磷单分子层进行纳米构图。通过将乙烯基膦酸二乙酯单层图案化成宽度范围从1μm到8 nm的线，在硅中制造掺杂剂线。随后通过快速热退火将掺杂剂驱入硅中以形成掺杂剂线。电学测量表明线宽和电导之间存在线性关系，表明单层构图工艺在纳米级的成功。如果可以减轻掺杂剂的热扩散，则可以将掺杂剂线按比例缩小到原子级。