Effect of ZrO_x/HfO_x bilayer structure on switching uniformity and reliability in nonvolatile memory applications

摘要

We have investigated the bilayer structure of binary oxides such as HfO_xand ZrO_x for applications to resistance memory. The ZrO_x/HfO_x bilayer structure shows a lower reset current and operating voltage than an HfO_x monolayer under dc sweep voltage. Furthermore, the bilayer structure exhibits a tight distribution of switching parameters, good switching endurance up to 105 cycles, and good data retention at 85 ℃. The resistive switching mechanism of memory devices incorporating the ZrO_x/HfO_x bilayer structure can be attributed to the control of multiple conducting filaments through the occurrence of redox reactions at the tip of the localized filament.