Improved Stability and Controllability in ZrN-Based Resistive Memory Device by Inserting TiO₂ Layer

In this work, the enhanced resistive switching of ZrN-based resistive switching memory is demonstrated by embedding TiO₂ layer between Ag top electrode and ZrN switching layer. The Ag/ZrN/n-Si device exhibits unstable resistive switching as a result of the uncontrollable Ag migration. Both unipolar and bipolar resistive switching with high RESET current were observed. Negative-SET behavior in the Ag/ZrN/n-Si device makes set-stuck, causing permanent resistive switching failure. On the other hand, the analogue switching in the Ag/TiO₂/ZrN/n-Si device, which could be adopted for the multi-bit data storage applications, is obtained. The gradual switching in Ag/TiO₂/ZrN/n-Si device is achieved, possibly due to the suppressed Ag diffusion caused by TiO₂ inserting layer. The current-voltage (I-V) switching characteristics of Ag/ZrN/n-Si and Ag/TiO₂/ZrN/n-Si devices can be well verified by pulse transient. Finally, we established that the Ag/TiO₂/ZrN/n-Si device is suitable for neuromorphic application through a comparison study of conductance update. This paper paves the way for neuromorphic application in nitride-based memristor devices.