Resistive switching and impedance spectroscopy in SiOx-based metal-oxide-metal trilayers down to helium temperatures

• Au/SiOx/TiN structures exhibit bipolar resistive switching (RS).
• The RS has been observed at low temperatures, down to 9 K.
• The RS is dependent on the atmospheric exposure of the Au top electrode.
• The impedance spectra of the HRS and the LRS have distinct temperature dependences.
• The RS is of filamentary nature.

In this work, Au/SiOx/TiN layered structures, obtained by magnetron sputtering deposition of silicon oxide (SiOx), are studied by means of I–V characteristics and impedance spectroscopy, in order to understand the underlying mechanisms of the resistive switching (RS) in these structures. After electroforming, the observed RS is bipolar with a resistance ratio higher than 102 between the high resistance state (HRS) and the low resistance state (LRS). The samples were subject to temperature dependent studies and the RS was observed down to 9 K, close to the liquid helium temperature. The switching voltage from the HRS to the LRS is dependent on the temperature and on the voltage application time used during the voltage sweep. The impedance spectra in the LRS and in the HRS show distinct temperature dependences, evidencing big differences between the two states, induced by the RS. There is a weak dependence of the resistance in the LRS on the area of the Au top electrodes. The observed RS is hence of filamentary nature and should involve redox processes and breakage and recovery of Si–O bonds, processes inhibited by isolating the Au top electrode from the surrounding atmosphere.