Dynamic conductance characteristics in HfOₓ-based resistive random access memory

Characteristics of HfOₓ-based resistive switching memory (RRAM) in Al/HfOₓ/Al and Al/AlOₓ/HfOₓ/Al structures were studied using a dynamic conductance method. Step-like RESET behaviors as well as pre- and post-RESET regions of operation were characterized. The results indicated that defects at the oxide interface caused cycling issues in the Al/AlOₓ/HfOₓ/Al structure. No such RESET behavior was observed for the Al/HfOₓ/Al structure. Current induced over-heating, which caused an early RESET event, could be avoided using current-sweep technique that caused less electrical and thermal stress in localized regions. The experimental results not only provided insights into potential reliability issues and power management in HfOₓ-based RRAM, but also helped clarifying the resistive switching mechanisms.