Characterising arsenic dopant incorporation in germanium

Germanium is receiving renewed interest for its utility in fabricating quantum technological devices, showcasing advantages over silicon such as higher electron mobility, stronger spin-orbit coupling, and enlarged Bohr radius. Its potential for nuclear spin-free isotopic enrichment and long donor coherence times, coupled with its already-established use in high-performance electronics, underscores its evolving relevance for the fabrication of devices such as a solid-state quantum computer. Recently, we have demonstrated that arsenic incorporates into the Ge(001) surface at room temperature [1]. This remarkable result means that there is no incorporation anneal required after the deposition of the precursor molecule, the incorporation probability of arsenic is unity, and lateral diffusion during fabrication should be minimal. Here, we present new work investigating the conductivity and confinement of arsenic in germanium with parallels to our similar recent results in silicon [2,3].

[1] Hofmann et. al., Angewandte Chemie, 62(7), (2023).

[2] Constantinou, et al., Advanced Science, 10, 2302101, (2023).

[3] D’Anna, Advanced Electronic Materials, 9, 2201212, (2023).