Comparative study of non-polar switching behaviors of NiO- and HfO_2-based oxide resistive-RAMs

摘要

This paper presents a detailed comparative study of the switching characteristics of resistive memory devices, with NiO or HfO_2 active materials and Pt electrodes, based on identical integration schemes. Material screening and qualification are performed using structural and composition analyses. Preliminary electrical investigations outline the non-polar switching behavior of both HfO_2 and NiO devices. Then, by using a specific test setup, we present a systematic comparative study of HfO_2 and NiO devices, clearly showing the tunability of the electrical characteristics with material type and process. HfO_2 devices lead to largest High Resistance State/Low Resistance State ratios and higher forming voltages compared to NiO cells, while reset voltages are similar. Data retention of both materials show highly stable Low Resistance State, while High Resistance State increases over time under 85 ℃ baking.