Nonlinear conductance quantization effects in CeOx/SiO2-based resistive switching devices

The electron transport in W/CeOx/SiO2/NiSi2 resistive switching devices fabricated onto a p+-type Si substrate is investigated. It is shown that the structures exhibit bipolar switching with conductance values in the low resistance state (LRS) close to integer and half integer values of the quantum unit G0 = 2e2/h, e and h being the electron charge and Planck constant, respectively. This behavior is consistent with the so-called nonlinear conduction regime in quantum point-contacts. A simple model for the LRS current-voltage characteristic based on the finite-bias Landauer formula which accounts for the right- and left-going conduction modes dictated by the constriction’s cross-section area and the voltage drop distribution along the filamentary path is reported.