Pulse-induced low-power resistive switching in HfO2 metal-insulator-metal diodes for nonvolatile memory applications

Abstract

The conduction process as well as the unipolar resistive switching behavior of Au∕HfO2∕TiN metal-insulator-metal structures were investigated for future nonvolatile memory applications. With current-voltage measurements performed at different temperatures (200–400K), the Poole–Frenkel effect as conduction process was identified. In particular, we extracted a trap energy level at ϕt=0.35±0.05eV below the HfO2 conduction band to which a microscopic origin is tentatively assigned. From current-voltage measurements of Au∕HfO2∕TiN structures, low-power (as low as 120μW) resistive switching was observed. The required forming process is shown to be an energy-induced phenomenon. The characteristics include electric pulse-induced resistive switching by applying pulses up to 100μs and a retention time upon continuous nondestructive readout of more than 104s.