Effects of Mg-Doping on HfO2-Based ReRAM Device Switching Characteristics

We report the switching characteristics of Mg-doped HfO2-based ReRAM devices consisting of Ru/Mg:HfO2/TiN/W stacks. The concentration of the Mg dopant was varied from 0% to 20% for four samples to show the impact on the forming voltage. In addition to reducing the forming voltage from 2.8 to 1.7 V, Mg doping in HfO2 also improved the repeatability in the initial device characteristics, switching characteristics, and retention. The mechanism of conduction was identified as Frenkel-Poole emission in doped and undoped samples in virgin resistance state (VRS). Further analysis showed that the increased conductance in the doped samples in VRS was due to higher carrier concentration.