Proton mobility in SiO2 thin films and impact of hydrogen and humidity on the resistive switching effect

ABSTRACTSilicon dioxide based Electrochemical Metallization (ECM) cells were intensively studied as a promising candidate for CMOS compatible non-volatile memory devices. The resistance of ECM cells can be switched between a high resistive (OFF) state and a low resistive (ON) state by applying a sufficient voltage or current pulse. This resistance transition is attributed to the formation and rupture of a few nanometers in diameter metallic filament. However, the metal ion transport which is believed to be responsible for the filamentary switching mechanism is not understood in detail. In case of SiO2 we suppose protons or humidity may enhance the metal ion transport.In this work we report our studies on the proton incorporation in amorphous SiO2 thin films focused on the impact of hydrogen and humidity on the resistive switching effect. The switching behavior was analyzed by current-voltage measurements performed at different ambient conditions. The incorporation of hydrogen has been confirmed by Time-of-Flight Secondary-Ion-Mass-Spectroscopy (ToF-SIMS). The results led to an expansion of the defect model proposed in the literature.