Comparative study of Al2O3, HfO2, and HfAlOx for improved self-compliance bipolar resistive switching

Abstract

The comparison of resistive switching (RS) storage in the same device architecture is explored for atomic layer deposition (ALD) Al₂O₃, HfO₂ and HfAlOx-based resistive random access memory (ReRAM) devices. Among them, the deeper high- and low-resistance states, more uniform V-SET-V-RES, persistent R-OFF/R-ON (>10²) ratio and endurance up to 10⁵ cycles during both DC and AC measurements were observed for HfAlOx-based device. This improved behavior is attributed to the intermixing of amorphous Al₂O₃/HfO₂ oxide layers to form amorphous thermally stable HfAlOx thin films by consecutive-cycled ALD. In addition, the higher oxygen content at Ti/HfAlOx thin films interface was found within the energy dispersive spectroscopy analysis (EDS). We believe this higher oxygen content at the interface could lead to its sufficient storage and supply, leading to the stable filament reduction-oxidation operation. Further given insight to the RS mechanism, SET/RESET power necessities and scavenging effect shed a light to the enhancement of HfAlOx-based ReRAM device as well.