Effect of ZrOx/HfOx bilayer structure on switching uniformity and reliability in nonvolatile memory applications

We have investigated the bilayer structure of binary oxides such as HfOx and ZrOx for applications to resistance memory. The ZrOx/HfOx bilayer structure shows a lower reset current and operating voltage than an HfOx monolayer under dc sweep voltage. Furthermore, the bilayer structure exhibits a tight distribution of switching parameters, good switching endurance up to 10(5) cycles, and good data retention at 85 degrees C. The resistive switching mechanism of memory devices incorporating the ZrOx/HfOx 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. (C) 2010 American Institute of Physics. [doi:10.1063/1.3491803]