Properties of BaTiO3 thin films deposited by radiofrequency beam discharge assisted pulsed laser deposition

BaTiO3 (Barium titanate, BTO) thin films were grown on Pt coated Si substrates by radiofrequency discharge assisted pulsed laser deposition (RF-PLD). A standard experimental set-up consisting in a pulsed YAG-Nd laser working at wavelength of 355 nm and incident fluence in the range of 2-3 J/cm(2) and assisted by a radio frequency plasma discharge (power RF of about 50-200 W in a O-2 gas flow ranged from 1 to 100 sccm) was used to produce films starting from a BTO ceramic target. Using a special configuration of radio frequency discharge, a beam of excited and/or ionized oxygen species was produced and directed toward the substrate: reactivity increases and oxygen vacancies in deposited thin films were effectively reduced, so thin films dielectric and ferroelectric properties were improved. High dielectric constant values (on the order of hundreds) with losses as low as 0.008-0.08 have been obtained: a comparison with films obtained without RF discharge has been carried out. (C) 2003 Published by Elsevier B.V.