MoO2 as a thermally stable oxide electrode for dynamic random-access memory capacitors

Abstract

Metallic MoO₂ is proposed as a new oxide electrode for dynamic random-access memory (DRAM) capacitors. Although noble metal oxide electrodes including RuO₂ and SrRuO₃ have attracted interest as capacitor electrodes, these materials have critical instability problems of ease-of-reduction during the subsequent annealing process. In contrast, MoO₂ shows excellent thermal stability of the structural and chemical properties even after annealing at 400 °C in both forming gas and O₂ atmospheres. In addition, MoO₂ electrodes induce the formation of a high temperature phase with a high dielectric constant, rutile TiO₂, by atomic layer deposition at the relatively low temperature of 250 °C because of the structural homogeneity between MoO₂ and rutile TiO₂. These results demonstrate that MoO₂ could be a promising electrode material for DRAM capacitors.