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

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 (200-400 K), the Poole-Frenkel effect as conduction process was identified. In particular, we extracted a trap energy level at phi(t) = 0.35 +/- 0.05 eV 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 120 mu W)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 100 mu s and a retention time upon continuous nondestructive readout of more than 10(4) s. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3139282]