Impact of the Heat Conductivity of the Inert Electrode on ReRAM Performance and Endurance

Abstract

We report on the impact of the inert electrode on the endurance of ReRAM memory cells. The baseline device Cu/TaOx/Pt/Ti is compared with six devices manufactured with different inert electrode constructions: Pt/Cr, Rh/Cr, Rh/Ti, Rh/Al2O3, Ir/Ti, and Ir/Cr, while the Cu electrode and the TaOx dielectric are identical. Although the glue layers Ti, Cr or Al2O3 are not an inherent part of the device proper, they have a tangible impact on the device endurance as well. We find consistently that inert electrodes with high thermal conductivities have superior endurance properties over an electrode with low thermal conductivity. Specifically, Rh(150/Cr(94) (numbers represent the heat conductivity in units of W/(m·K)) is not only superior to Pt(72)/Ti(20) but also to Rh(150)/Ti(20) device. We explain the impact of the heat conductivity of the inert electrode on the endurance by the deformation of the Cu filament due to Cu fluxes during the switching cycles.