Preferential c-axis orientation and dielectric constants of thin BaTiO3 films deposited on Si wafers by a low energy ion beam assisted deposition technique

Thin BaTiO3 films were deposited on thin TiN film covered Si wafers by ion beam assisted deposition comprising of two electron beam evaporators for evaporating Ti and BaCO3 and an electron cyclotron resonance ion source for ionizing O-2. Films deposited using 25 eV oxygen ion beams had many small X-ray diffraction (XRD) peaks from tetragonal (t-) BaTiO3, BaTi2O5 and Ba2TiO4. BaTi2O5 grew predominantly in films deposited using 50 eV oxygen ion beams. Films deposited using oxygen ion beams with energies above 200 eV had large XRD peaks from t-BaTiO3 and small XRD peaks from Ba2TiO4. Remanent polarizations and dielectric constants increased with increasing oxygen ion beam energy while the films had approximately the same coercive field regardless of composition. Films deposited using 300 eV oxygen ion beams had a remanent polarization of 0.048 mC/cm(2) and a coercive field of 0.64 MV/cm. (c) 2007 Elsevier B.V. All rights reserved.