Amorphous TaOx thin films were deposited on a PtOx electrode by low pressure chemical vapor deposition (LPCVD) in Ar atmosphere with the use of Ta(OC2H5)(5) as a precursor. An in situ reduction of PtOx electrode was found during the LPCVD Process, and the active oxygen released from the reduction of the PtOx electrode enhanced the deposition of TaOx films with an activation energy of 0.43 +/- 0.03 eV lower than. the value, 0.57 +/- 0.01 eV, obtained from deposition on the Pt electrode. The growth of TaOx was controlled by the reduction reaction of PtOx, which had an activation energy of 0.32 +/- 0.04 eV, and the activated oxidation/decomposition reaction of Ta(OC2H5)(5), Which had a low activation energy of 0.11 +/- 0.05 eV. It Was also found that the, reduction of PtOx roughed the surface of the PtOx electrode, and the rough structure significantly enhanced the capacitance of Pt/TaOx/PtOx although an increase of the leakage current also accompanied it. (C) 2003 American Vacuum Society.