Transport and Tunneling in Atomic-scale Acceptor-based Devices in Silicon

Ultradoped silicon provides a novel frontier for the exploration of electronic transport in a disordered potential with extremely high carrier concentrations (> 10¹⁴ cm^-2).  Atomic-precision advanced manufacturing (APAM) techniques associated with scanning tunneling microscopy (STM)-based lithography can be used to confine the dopants to quasi-2D regions of silicon having dimensions from microns to angstroms. This plays an essential role in building dopant-based nanoelectronic devices for single dopant atom qubit measurement and control. This process has recently been extended to include acceptor doping with B. Here, we present the details of fabrication and measurement of gated Si∶B wires and single hole transistors (SHTs) to provide insight into transport and tunneling in these planar, atomic-scale devices at low temperatures. Such a detailed understanding provides the pathway towards engineering and realization of single B atom-based devices in silicon.