Conducting and switching characteristics of SiO films with Al and Ag electrodes

The field and temperature dependence of the conductivity in SiO films (550–2800 Å) was investigated using evaporated Al electrodes. Reversible switching of resistance occurred when one or both electrodes were made of Ag. Depending on the magnitude of the first voltage pulse applied to the sample (“forming”) we observed either threshold switching or one of two different memory effects. The resistance of the completely formed sample could be switched between 300 ohm and 109 ohm simply by changing the duration of the voltage pulses. Even after a large number (> 500 000) of switching operations, the sample retained its memory element character. A model to explain the memory effect by metal diffusion from the electrodes is presented.