Nanoscale electronics based on two-dimensional dopant patterns in silicon

A nanoscale fabrication process compatible with present Si technology is reported. Preimplanted contact arrays provide external leads for scanning tunneling microscope (STM)-defined dopant patterns. The STM’s low energy electron beam removes hydrogen from H terminated Si(100) surfaces for selective adsorption of ${\mathrm{PH}}_3$ precursor molecules, followed by room temperature Si overgrowth and 500 °C rapid thermal anneal to create activated P-donor patterns in contact with ${\mathrm{As}}^{+}$ -implanted lines. Electrical and magnetoresistance measurements are reported here on 50 and 95 nm-wide P-donor lines, along with Ga-acceptor wires created by focused ion beams, as a means for extending Si device fabrication toward atomic dimensions.