Resistance switching properties of sol-gel derived SrZrO3 based memory thin films

Sol-gel derived SrZrO3 based metal/insulator/metal (MIM) devices were fabricated to study their reversible resistance switching properties operated by dc voltage sweep and voltage pulses. The leakage-state of the device is changed from the original-state and finally switched between the high leakage-state (H-state) and the low leakage-state (L-state). The resistance ratio between the H-state and the L-state is about 10(4), and the leakage-states are not changed without power supply, which is suitable for nonvolatile memory application. The conduction mechanisms of the original-state, the H-state and the L-state obey Schottky emission, Frenkel-Poole emission and Ohmic conduction, respectively. The first device resistance switching, called the forming process, changed from the original-state to the H-state. The switching time from the H-state to the L-state is much longer than that from the L-state to the H-state and that of the forming process. The decay behaviours of leakage current after resistance switching are influenced by pulse width and voltage stress directions. The switching time can be accumulated to switch the device from the H-state to the L-state, which could be a guide to multi-level memory applications. The model of conducting paths can well explain the electrical behaviours of our resistance switching devices.