MoO ₂ as a thermally stable oxide electrode for dynamic random-access memory capacitors

Metallic MoO ₂ is proposed as a new oxide electrode for dynamic random-access memory (DRAM) capacitors. Although noble metal oxide electrodes including RuO ₂ and SrRuO ₃ have attracted interest as capacitor electrodes, these materials have critical instability problems of ease-of-reduction during the subsequent annealing process. In contrast, MoO ₂ shows excellent thermal stability of the structural and chemical properties even after annealing at 400 °C in both forming gas and O ₂ atmospheres. In addition, MoO ₂ electrodes induce the formation of a high temperature phase with a high dielectric constant, rutile TiO ₂ , by atomic layer deposition at the relatively low temperature of 250 °C because of the structural homogeneity between MoO ₂ and rutile TiO ₂ . These results demonstrate that MoO ₂ could be a promising electrode material for DRAM capacitors.