Magnetotransport Characterization of Atomic-scale B-doped δ-layer devices in Si*

Atomic precision advanced manufacturing (APAM) processes in silicon have advanced significantly over the past decade as researchers strive towards the ultimate realization of a single dopant qubit based Kane quantum computer architecture. Here, we demonstrate the fabrication of atomic-scale, B-doped δ-layer devices in Si through area selective deposition of BCl₃ on Si(100) and measure the magnetotransport properties of resulting Hall bar devices. Magneto and Hall measurements conducted at 3 K revealed a sheet resistance of 1.9 kΩ without performing incorporation or activation anneal. Relatively high hole concentrations, 1.9 x 10¹⁴ cm², and mobilities, ∼39 cm² V ⁻¹ s ⁻¹, within a sub-nanometer transport layer were routinely obtained on multiple samples. We further demonstrate STM-based lithography techniques to create B-doped wires and tunnel junctions and report on their electrical characterization. These findings provide a pathway towards the realization of atomic-scale acceptor-based devices and the exploration of superconductivity in silicon.