Investigation of RuO_2-Incorporated Pt Layer as a Bottom Electrode and Diffusion Barrier for High Epsilon Capacitor Applications

摘要

The effects of the amount of RuO_2 added in the Pt film on the electrical properties of the deposited Pt-RuO_2 film on the n~(2+)-poly-Si substrate by using metal mask of 500 m m dot in size were investigated at the temperature range of 500-700 ℃ in air. When the Pt film was prepared without RuO_2 addition, it showed the higher total resistance and nonlinear characteristics, attributed to the oxidized layer at the Pt~(2+)-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 RuO_2 incorporation exhibited the lower total resistance and ohmic behavior up to 700 ℃ and suppressed the reaction of Pt-silicide up to 800 ℃. In the latter case, the incorporation of ruthenium dioxide (RuO_2) into the Pt bottom electrode layer led to the retardation of the interdiffusion of oxygen, Si, and Pt up to 700 ℃, resulting from RuO_2 stuffing effect in the polycrystalline Pt film. Consequently, this implies that the RuO_2-stuffed Pt layer is expected to perform as a bottom electrode as well as diffusion barrier.