DEPOSITION OF BATIO3 THIN-FILMS BY PLASMA MOCVD

Barium titanium trioxide (BaTiO3) thin films were deposited on fused s ilica or silicon wafer substrate from barium dipivaloylmethanate (II) (Ba(dpm)(2)) and titanium tetraisopropoxide (TV) (TTIP) used as precur sors in an oxygen microwave plasma. The substrates were dielectrically heated and the substrate temperatures were around 900 K during the fi lm deposition. The deposition was performed for 15 min and the deposit s were identified as BaTiO3 by means of X-ray diffraction, X-ray photo electron spectroscopy, infrared spectroscopy, and ellipsometry. Oxygen and barium atoms and TiO and CO molecules were identified in the plas ma. These species would produce higher deposition rates at lower subst rate temperatures than those did in the usual thermal metalorganic che mical vapor deposition (MOCVD). The dielectric constant of the BaTiO3 thin film that was directly deposited on the silicon wafer substrate w as as low as 10(1) order of magnitude. Because the deposit reacted wit h the substrate and an interdiffusional layer was formed, the platinum layer was coated on the silicon wafer substrate in order to prevent t he formation of an interdiffusional layer. The dielectric constant the n increased to 10(3) order of magnitude. (C) 1997 Elsevier Science S.A .