Investigation of RuO₂-incorporated Pt layer as a bottom electrode and diffusion barrier for high epsilon capacitor applications

The effects of the amount of RuO₂ added in the Pt film on the electrical properties of the deposited Pt-RuO₂ film on the n²⁺-poly-Si substrate by using metal mask of 500 m m dot in size were investigated at the temperature range of 500-700 °C in air. When the Pt film was prepared without RuO₂ addition, it showed the higher total resistance and nonlinear characteristics, attributed to the oxidized layer at the Pt/n²⁺-poly-Si interface formed by reaction between the indiffused oxygen through Pt grain boundaries and Si during annealing in air. The Pt layer fabricated by RuO₂ incorporation exhibited the lower total resistance and ohmic behavior up to 700 °C and suppressed the reaction of Pt-silicide up to 800 °C. in the latter case, the incorporation of ruthenium dioxide (RuO₂) into the Pt bottom electrode layer led to the retardation of the interdiffusion of oxygen, Si, and Pt up to 700 °C, resulting from RuO₂ stuffing effect in the polycrystalline Pt film. Consequently, this implies that the RuO₂-stuffed Pt layer is expected to perform as a bottom electrode as well as diffusion barrier.