Resistive Switching of SnO₂ Thin Films on Glass Substrates

Abstract

Resistive switching of SnO2 thin films deposited by RF magnetron reactive sputtering at room temperature was investigated. Ag/SnO2/Ti structures were fabricated on glass substrates for current-voltage characteristics evaluation. Repeatable unipolar switching was observed using a compliance current of 10 mA and limiting the reset voltage between 0.8 and 1.2 V. Different top contact area were fabricated indicating a filamentary forming mechanism. Furthermore, a retention memory analysis was performed indicating an acceptable device behavior through time. An Ohmic conduction process was found in LRS and HRS. However for HRS, Ohmic conduction was observed only at voltages lower than 0.3 V. At higher voltages, conduction is not explained well by Ohmic, Poole-Frankel, Schottky emission, or space-charge-limited conduction. This indicates that a material structural change occurs at voltages above 0.3 V which is the onset to switching from HRS to LRS.