Narrow, highly P-doped, planar wires in silicon created by scanning probe microscopy

We demonstrate the use of a scanning tunnelling microscope (STM) to pattern buried, highly planar phosphorus-doped silicon wires with widths down to the sub-10 nm level. We confirm the structural integrity of these wires using both buried dopant imaging techniques and ex situ electrical characterization. Four terminal I–V characteristics at 4 K show ohmic behaviour for all wires with resistivities between 1 and 24 × 10 −8 Ω cm. Magnetotransport measurements reveal that conduction is dominated by disordered scattering with quantum corrections consistent with 2D weak localization theory. Our results show that these quantum corrections become more pronounced as the electron phase coherence length approaches the width of the wire.