Influence of SiO2 Layer on Resistive Switching Properties of SiO2/CuXO Stack Structure
CuxO and SiO2 thin films were deposited using a radio-frequency magnetron sputter on Pt/Ti/SiO2/Si substrates to form SiO2/CuxO/Pt and CuxO/Pt structures. The current-voltage characteristics were measured by DC voltage sweeping using a tungsten (W) probe. The two structures needed a large voltage to initiate the first resistive switching; this sweep was called the forming process. Afterwards, the resistances of the two structures could be switched reversibly between the low-resistance-state (LRS) and high-resistance-state (HRS) by applying a DC voltage. The conduction mechanisms of the LRS and the HRS were dominated by Ohmic conduction. Structures with non-destructive readout characteristics and long retention time were suitable for use in non-volatile memory. The difference between resistive switching in W-probe/SiO2/CuxO/Pt and W-probe/CuxO/Pt structures was investigated. The additional SiO2 layer decreased the switching voltages and currents; this should be due to the presence of pinholes within the SiO2 layer. The influence of SiO2 thickness on the resistive switching characteristics was also investigated. The switching voltages and currents, except the forming voltage, decreased as the thickness of SiO2 decreased. The conducting filament model with a thermochemical reaction was suggested to best explain the resistive switching behavior that was observed.
Chengming Li, Chengbao Jiang, Zhiyong Zhong and Yichun Zhou
C. Y. Liu et al., "Influence of SiO2 Layer on Resistive Switching Properties of SiO2/CuXO Stack Structure", Materials Science Forum, Vol. 687, pp. 106-111, 2011