Comparative study of Al 2 O 3 , HfO 2 , and HfAlO x for improved self‐compliance bipolar resistive switching

The comparison of resistive switching ( RS ) storage in the same device architecture is explored for atomic layer deposition ( ALD ) Al 2 O 3 , HfO 2 and HfAlO x ‐based resistive random access memory (Re RAM ) devices. Among them, the deeper high‐ and low‐ resistance states, more uniform V SET ‐ V RES , persistent R OFF / R ON (>10 2 ) ratio and endurance up to 10 5 cycles during both DC and AC measurements were observed for HfAlO x ‐based device. This improved behavior is attributed to the intermixing of amorphous Al 2 O 3 /HfO 2 oxide layers to form amorphous thermally stable HfAlO x thin films by consecutive‐cycled ALD . In addition, the higher oxygen content at Ti/HfAlO x 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 HfAlO x ‐based Re RAM device as well.