Electrical properties of thin Ta2O5 films obtained by thermal oxidation of Ta on Si

Tantalum pentoxide films (13-260 nm) on p-type Si have been prepared by thermal oxidation at 673-873 K of rf sputtered Ta films and have been studied using Al-Ta2O5-Si capacitors. Both dielectric constant and refractive index were found to depend on the thickness of the Ta2O5 layers. Layers with a dielectric constant of 25-32 were obtained. A decreasing trend in the leakage current was found upon increasing oxidation temperature from 673 to 873 K. Leakage current density of (10(-8) to 3 x 10(-7)) A cm(-2) at 1 MV cm(-1) effective field was achieved. (C) 1998 Elsevier Science Ltd. All rights reserved.