Resonant tunneling properties of SiO2/polycrystalline Si/SiO2 multilayers fabricated by radio-frequency magnetron sputtering

SiO2/poly-Si/SiO2 double-barrier structures fabricated by radio-frequency magnetron sputtering are shown to exhibit negative differential resistance (NDR) that is attributed to resonant tunneling (RT) at low temperatures. An annealing process conducted after the multilayer deposition is found to effectively yield stable NDR. Five percent of all of the fabricated devices exhibit clear NDR below 50 K. Other devices with the same multilayered structure exhibit staircase-like current-voltage curves caused by the Coulomb blockade (CB) or by interplay between the RT and CB. The requisites of the poly-Si layer microstructures for the realization of stable RT are elucidated. (C) 2015 AIP Publishing LLC.