A high quality high temperature compatible Tantalum oxide film for advanced dRAM applications

A reactive sputtering technique was used for the preparation of Ta2O5films on Si substrates. The film was found either comparable or superior to the best results reported in the literature [1-5] in breakdown field strength, dielectric constant and/or leakage current. Thermal oxidation of the Ta2O5film resulted in the growth of SiO2under Ta2O5. The electrical characteristics of the oxidized film were close to pure SiO2with an advantage of 20% higher storage charge density. From underlying silicon oxidation kinetics, an activation energy of 0.9 eV was found for the oxygen diffusion in Ta2O5. The Ta2O5film has shown potential for applications in advanced dRAMs.