Impact of oxide bottom electrodes on resistive switching behavior associated with oxygen vacancy dynamics in Al/ZrO₂/BE ReRAM structures

This study investigates the impact of oxide bottom electrode (BE) material and orientation on the resistive switching (RS) characteristics of Al/ZrO₂-based ReRAM devices. Devices with different oxide BEs, including (400)- and (222)-oriented ITO BEs deposited under pure argon and argon–oxygen (20% O₂) sputtering atmospheres, as well as SrRuO₃ (SRO), show distinct RS behaviors. The Al/ZrO₂/(400)-ITO and Al/ZrO₂/SRO devices demonstrate stable bipolar RS performance, with (400)-ITO enabling an abrupt reset process, a wider memory window (> 10⁴), and superior stability, while SRO devices exhibit gradual reset transitions with lower power consumption. Furthermore, the crystallographic orientation control applied to ITO BE significantly affects the V_O dynamics and RS performance, with (222)-ITO devices exhibiting irreversible RS behavior. It is irrefutable that BE material and its orientation can strongly influence RS performance by modulating the V_O dynamics, electric field distribution, and conductive filament behavior. These findings underscore the importance of BE properties in optimizing ReRAM performance and provide valuable guidance for the development of high-efficiency memory devices.