Quantum point contact model of filamentary conduction in resistive switching memories

The quantum point contact (QPC) model, originally developed to model the conduction after soft and hard breakdown events in thin-oxide MOS devices, is applied to resistive random access memories (RRAM). The QPC model is based on the idea that the conducting filament (CF) behaves as a quantum wire and it is shown to adequately describe the conduction in the low-resistance state (LRS) and in the high-resistance state (HRS). These two regimes show linear and nonlinear current-voltage (I-V) characteristics, respectively. In the LRS, the CF shows metallic conduction properties and the signature of conductance quantization. In the HRS, the conduction is linear at low and high enough voltages, and it is strongly nonlinear in the transition between these two linear regimes. After showing that the model is adequate for both the LRS and the HRS, the QPC picture is used to provide a compact model for the whole dynamic switching cycle of CF-based RRAM devices and memristors.