Electrical properties of Ta₂O₅ thin films deposited on Cu

The electrical and dielectric properties of reactively sputtered Ta₂O₅ thin films with Cu as the top and bottom electrodes forming a simple metal insulator metal (MIM) structure, Cu/Ta₂O₅/Cu/n-Si, were studied. Ta₂O₅ films subjected to rapid thermal annealing (RTA) at 800°C for 30 s in N₂ ambient crystallized the film, decreased the leakage current density and resulted in reliable time-dependent dielectric breakdown characteristics. The conduction mechanism at low electric fields (< 100 kV/cm) is due to Ohmic conduction; however, the Schottky mechanism becomes predominant at high fields (> 100 kV/cm). Present studies demonstrate the use of Cu as a potential electrode material to replace the conventional precious metal electrodes for Ta₂O₅ storage capacitors.