Low temperature deposition of epitaxial BaTiO3 films in a rotating disk vertical MOCVD reactor

Epitaxial BaTiO3 thin films were deposited on MgO (100) in a rotating disk vertical metalorganic chemical vapor deposition (MOCVD) reactor at 700 degrees C. The metalorganic sources used were titanium tetraisopropoxide and the highly volatile fluorinated barium precursor (Ba(hfa)(2)(.)pentaethyleneglycolethylbutylether(PEB)). To facilitate growth at the lower temperature while suppressing the formation of BaF2 impurity phases, a strong oxidant consisting of a mixture of 80% N2O and 20% O-2 was employed. The BaTiO3 films deposited at 700 degrees C are phase pure and show only BaTiO3 {001} x-ray diffraction peaks. The x-ray rocking curve full width at half maximum (FWHM) of the BaTiO3 (002) peak was 0.82 degrees. The fourfold symmetry and coincident position of the {110} peaks for both the film and substrate confirms in-plane epitaxy of cube-on-cube orientation. The Phi-scan FWHM of the BaTiO3 film is 1.05 degrees. The growth temperature in this work is lower than the temperatures used in most comparable thermal MOCVD epitaxial oxide processes for BaTiO3. (c) 2005 American Vacuum Society.