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 degrees C in both forming gas and O-2 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 degrees 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.