Role of interface reaction on resistive switching of Metal/a-TiO2/Al RRAM devices

For the clear understanding of the role of interface reaction between top metal electrode and titanium oxide layer, we investigated the effects of various top metals on the resistive switching in Metal/a-TiO2/Al devices. The top Al device with the highest oxygen affinity showed the best memory performance, which is attributed to the fast formation of interfacial layer (Al-Ti-O), as confirmed by high resolution transmission electron microscopy and electron dispersive spectroscopy. Hence, we concluded that the interface layer, created by the redox reaction between top metal electrode and TiO2 layer, plays a crucial role in bipolar resistive switching behaviors of metal/TiO2/Al systems.