An Increasing High Resistance State Phenomenon in Al/VOx/Cu Resistive Switching Device

Abstract

In this paper, we reported increasing high resistance state (HRS) phenomenon of Al/VOx/Cu resistive random access memory (RRAM). The current of HRS became lower in current-voltage (I-V) curves and resistance of HRS gradually increased from a lower pristine sate to a higher HRS during cycling operation. Schottky emission theory was employed to investigate the HRS conduction. We found that the slope of HRS I-V curves on ln(J) and sqrt(V) plot decreased after cycling operation. According to Schottky emission theory, we concluded that generation of AlOx layer between Al electrode and VOx film was the cause of increasing HRS resistance. We finally verify the conclusion by data retention under constant voltage stress.