A new design concept for diffusion barriers in high-density memory capacitors was suggested, and both the RuTiN (RTN) and the RuTiO (RTO) films, as sacrificial oxygen diffusion barriers, were proposed. The newly developed RTN and RTO barriers showed much lower sheet resistance, as reported by others, than various barriers including binary and ternary nitrides up to 800degreesC, without a large increase in resistance. For both the Pt/RTN/TiSix/n(++) poly-plug/n(+) channel layer/Si and the Pt/RTO/RTN/TiSix/n(++) poly-plug/n(+) channel layer/Si contact structures, contact resistance, the most important electrical parameter for the diffusion barrier in the bottom electrode structure of capacitors, exhibited as low as 5 kOmega, even after annealing up to 750degreesC. Moreover, when the RTN film was inserted as a glue layer between the bottom electrode Pt layer and the TiN barrier film in the chemical vapor deposited-(Ba, Sr)TiO3 simple stack-type structure, the thermal stability of the RTN glue layer was observed to be 150degreesC higher than that of the TiN glue layer. Correspondingly, new RTN and RTO films, as diffusion barriers for oxygen, are very promising materials for achieving the high-density capacitors.