Enhanced resistive switching properties of HfAlOx/ZrO2- based RRAM devices
P.R. Sekhar Reddy, Venkata Raveendra Nallagatla, Yedluri Anil Kumar, G. Murali
Abstract
Resistive Random-Access Memory (RRAM) devices are recognized as potential candidates for next-generation memory devices, due to their smallest cell size, high write/erase speed, and endurance. Particularly, the resistive switching (RS) characteristics in oxide materials have offered new opportunities for developing CMOS-compatible high-density RRAM devices. In this study, the RS behavior of HfAlOx/ZrO2 thin films sandwiched structure between TiN bottom electrode and Au top electrodes were investigated. It was found that Au/HfAlOx/ZrO2/TiN stacks were superior in terms of RS performance when compare to Au/HfAlOx/TiN memory stacks. The devices demonstrated a good resistance ratio of high resistance state and low resistance state ∼103 for Au/HfAlOx/TiN and ∼105 for Au/HfAlOx/ZrO2/TiN stacks, respectively. Both stacks showed good retention characteristics (>104 s) and endurance (>103 cycles). The experimental current-voltage characteristics fitted with different conducting mechanisms, the linear lower bias region is dominated by ohmic conductivity, whereas the non-linear higher bias region was dominated by space-charge limited current conduction mechanism.