Ohmic conduction of sub-10nm P-doped silicon nanowires at cryogenic temperatures

Abstract
We investigate the conduction properties of an embedded, highly phosphorus-doped nanowire with a width of 8 nm lithographically defined by scanning tunneling microscope based patterning of a hydrogen-terminated Si(100):H surface. Four terminal I - V measurements show that ohmic conduction is maintained within the investigated temperature range from 35 K down to 1.3 K . A prominent resistance increase is observed below ∼ 4 K which is attributed to a crossover into the strong localization regime. The low temperature conductance follows a one-dimensional variable range hopping model accompanied by positive magnetoresistance which dominates over weak localization effects at low temperature.