Properties of Ru and RuO2 thin films prepared by metalorganic chemical vapor deposition

Ru and RuO2 thin films were deposited on Si substrates, using a metalorganic precursor of ruthenium carbonyl [Ru-3(CO)(12)], by metalorganic chemical vapor deposition (MOCVD), and their properties were investigated. Ru or RuO2 single phase could be obtained by controlling the flow rate of the oxidant gas (O-2). When the Ru film was annealed in oxygen atmosphere, oxygen atoms diffused through the Ru layer, resulting in the oxidation of ruthenium. The compositional. uniformity of RuO2 thin films in the thickness direction was good, and interdiffusion at the interface between RuO2 and Si was not observable even alter the post-annealing process. The deposition rate of RuO2 thin films is highest at 550 degrees C. All RuO2 thin films showed a dense and smooth microstructure. It was demonstrated that a larger grain size of the Trim resulted in lower resistivity, and that post-annealing decreased the resistivity. The larger the grain size of the RuO2 film, the greater is the decrease in resistivity by annealing.